The 24th International Spin Symposium

Asia/Tokyo
Matsue, Shimane Prefecture, Japan

Matsue, Shimane Prefecture, Japan

Matsue City, Shimane Prefecture, Japan
,
Description

We are pleased to announce that the registration for the 24th International Spin Symposium (SPIN2021) is now open. The symposium will be held at Kunibiki Messe Convention Center in Matsue, Shimane prefecture, Japan in October 18-22, 2021, in a hybrid style, i.e., both of in-person (onsite) and remote (online) participation will be possible.

Second Circular (pdf)

We are pleased to announce that the registration for the 24th International Spin Symposium (SPIN2021) is now open at the symposium webpage: https://spin2021.riken.jp
The symposium will be held at Kunibiki Messe Convention Center in Matsue, Shimane prefecture, Japan in October 18-22, 2021, in a hybrid style, i.e., both of in-person (onsite) and remote (online) participation will be possible. Based on the current status of COVID-19, we don’t know how much in-person participation will be possible, and we cannot respond to
visas or invitation letters at this time. We hope that the situation will improve so that as many people as possible can participate in-person.

This conference series has been held jointly since 2000, combining the High Energy Spin
Symposia and the Nuclear Polarization Conferences. The most recent symposia took place in
Dubna, Russia (2012), Beijing, China (2014), Urbana Champaign, USA (2016), and Ferrara,
Italy (2018). The scientific program of SPIN2021 will include topics related to spin
phenomena in particle and nuclear physics as well as those in related fields. The symposium
format consists of talks in plenary and parallel sessions. We will have poster sessions as well.
Although we will not organize a social event to minimize the possibility of COVID-19
infection, we would like to introduce Matsue city and Shimane prefecture as a very attractive
place in Japan. This place is a famous and interesting area with over 2,000 years of history
ranging from the Japanese creation myth era to modern times. You can find the Izumo Taisha
(Grand Shrine), the historic Tatara Iron Mill, Matsue Castle, famous Japanese gardens and
other popular sights.
September 30, 2021. We will collect registration fees to cover the costs of publishing the
symposium proceedings and holding the symposium in a hybrid style. Please see the
registration section below. There will be no registration fee for non-presenting audience
participants, but we would appreciate your contribution of many presentations. If you have a
question, please do not hesitate to ask us. We look forward to meeting you in Matsue, albeit
in a hybrid style.
Yuji Goto and Tomohiro Uesaka (Co-Chairs)
on behalf of the Local Organizing Committee

Plenary Speakers:
Already confirmed (Note: talk titles are tentative):
V. Tishchenko (BNL), Measurement of muon g-2
B. Malaescu (LPNHE), Theory of muon g-2
S. Henrot-Versille (Orsay), Polarization aspects of CMB
E. Saito (Tokyo), Spintronics
N. Sato (Jefferson Lab), Theoretical studies on the nucleon helicity structure
F. Kunne (Saclay), Experimental studies on the high-energy spin physics in
the fixed-target experiments
F. Ringer (LBNL), Progress on fragmentation-function studies
A. Gasparian (North Carolina), Progress on proton-radius measurements
Z. Liang (Shandong), Spin polarization and asymmetry in heavy-ion collisions
C. Alexandrou (Cyprus), Progress on Lattice QCD studies on the spin physics
J. Doyle (Harvard), EDM search with cold molecules
M. Kitaguchi (Nagoya), T-violation in neutron scattering
O. Evdokimov (UIC), EIC physics overview
L. Pappalardo (INFN Ferrara), Polarized target experiments at LHC
J. Pretz (Aachen), EDM searches in storage rings
M. Iinuma (Hiroshima), Progress on the solid polarized target

Plenary speakers on the following topics will be announced later.
* Theoretical studies on the 3D structure of the nucleon
* Experimental studies on the high-energy spin physics in the collider experiments
* Neutron EDM
* Experiment with photon beams
* LEPS experiments
* Polarized proton experiments
* ELI-NP project overview
* EIC accelerator
* NMR in biology
* Polarized target for protein crystal studies

Venue

The symposium will be held at
Kunibiki Messe Convention Center
http://www.kunibikimesse.jp/14.html
in Matsue, Shimane prefecture, Japan.
For access information to the Kunibiki Messe, please see:
http://www.kunibikimesse.jp/60.html
Accommodation and visitor information
There are many hotels available in Matsue ranging from affordable to high quality hotels.
Matsue can be easily accessed from two nearby local airports, Izumo airport and Yonago
airport, both of which are connected to Japan's large international airports in Tokyo, Osaka, etc.
For visitor information, please see Matsue city official travel guide:
https://www.visit-matsue.com/
Schedule
Given the hybrid style of the symposium, the plenary and parallel sessions are arranged such
that at least some of them are convenient to participants from outside Asia.

Important dates:
Registration / Abstract submission open: July 20, 2021
Notification for contributed talks: August 31, 2021
Registration
Please register at the Indico webpage of SPIN2021:
https://indico2.riken.jp/event/3082/registrations/144/

Registration fees:

Registration fee for onsite regular participants: 15,000 JPY, students: 10,000 JPY
Registration fee for online oral/poster presenters: 10,000 JPY, students: 5,000 JPY
Registration fee for online audience: FREE

First circular

First circular
24th International Symposium on Spin Physics
October 18-22, 2021, Matsue, Japan

We are pleased to announce that the 24th International Symposium on Spin Physics will be held at Kunibiki Messe Convention Center in Matsue, Shimane prefecture, Japan in October 18-22, 2021. This conference was originally scheduled to be held in 2020 as "SPIN 2020" but postponed because of the worldwide COVID-19 pandemic. Although it is still difficult to predict the situation of the pandemic, we believe that we should resume this conference.

The conference will be held in a hybrid style (i.e., both of in-person (onsite) and online participations will be possible). Recently, we have successfully tested it with a domestic conference on spin physics and think this style is useful to invigorate our scientific discussions under the present situation of the pandemic.

This conference series has been held jointly since 2000, combining the High Energy Spin Symposia and the Nuclear Polarization Conferences. The most recent symposia took place in Dubna, Russia (2012), Beijing, China (2014), Urbana Champaign, USA (2016), and Ferrara, Italy (2018). SPIN 2021 will be co-chaired by Yuji Goto and Tomohiro Uesaka (RIKEN).

The scientific program of SPIN 2021 will include topics related to spin phenomena in particle and nuclear physics as well as those in related fields.
The symposium topics cover acceleration, storage and polarimetry of
polarized beams; applications of spin physics; fundamental symmetries
and physics beyond the standard model; future facilities and
experiments; nucleon structure; polarized ion and lepton sources and
targets; spin physics in nuclear reactions and nuclei; spin physics
using photon, lepton and hadron probes; and the spin structure of
hadrons. The symposium format consists of talks in plenary and parallel sessions.

Although we will not organize a social event to minimize the possibility of the infection to COVID-19 on the site, we would like to introduce Matsue city and Shimane prefecture as a very attractive place in Japan. This place is a famous and interesting area with over 2,000 years of history ranging from the Japanese creation myth era to modern times.
You can find the Izumo Taisha (Grand Shrine), the historic Tatara Iron
Mill, Matsue Castle, famous Japanese gardens and other popular sights
here.
Matsue can be easily accessed from two nearby local airports, Izumo
airport and Yonago airport, both of which are connected to Japan's
large international airports in Tokyo, Osaka, etc.

A preliminary webpage for SPIN 2021 can be accessed at
http://spin2021.riken.jp
The page will be updated with additional information when available.
directly or send an email to contact-spin2021@ml.riken.jp

We look forward to meeting you in Matsue.

Yuji Goto and Tomohiro Uesaka (Co-Chairs)
on behalf of the Local Organizing Committee

Registration
Spin 2021 Registration
Participants
• Abdel Nasser Tawfik
• Alexandr Chumakov
• Alexandre Lebedev
• Ananya Paul
• Anatolii Koval
• Andras Laszlo
• Andreas Lehrach
• Andrei Poblaguev
• andrzej sandacz
• Ashot Gasparian
• Barbara Pasquini
• Chrysovalantis Kannis
• Constantia Alexandrou
• Devon Loomis
• Dillon Fitzgerald
• Dingyu Shao
• dustin keller
• Fanyi Zhao
• Fatiha Benmokhtar
• Felix Ringer
• Frank Rathmann
• Georgi Georgiev
• Gordon Baym
• Haiyan Gao
• Hans Stroeher
• Hendrik Smitmanns
• Hideki Kohri
• Hyeon-Dong Son
• Itaru Nakagawa
• Jackson Pybus
• John Lajoie
• john terry
• Jose Goity
• Josh Pierce
• Kazuhisa Kakurai
• Kenichiro Tateishi
• Kurt Aulenbacher
• Luciano Pappalardo
• Marco Zaccheddu
• Maria Zurek
• Masaki Sasano
• Masanori Wakasugi
• Matthew McEneaney
• Max Vitz
• Mikio Sakurai
• Miroslav Finger
• Motoki Sato
• Mriganka Mouli Mondal
• Naohito SAITO
• Nobuo Hinohara
• Oleg Tereshchenko
• Otari Javakhishvili
• Paolo Lenisa
• POONAM CHOUDHARY
• Ralf Engels
• Ralf Seidl
• Salvatore Fazio
• Takashi Ichihara
• Takumi Doi
• Thomas Roser
• Tianbo Liu
• Tomohiro Uesaka
• Tomotsugu Wakasa
• Valery Tyukin
• Vera Shmakova
• Volker Hejny
• Willem van Oers
• Xiaoyu Wang
• Yasuhiro Sakemi
• Yasushi Watanabe
• Yoshiyuki Miyachi
• Yuichi Ichikawa
• Yuji Goto
• Yuki ITO
• Yukie Maeda
• Yulia Furletova
• Yusuke Takeuchi
• Zhenyu Ye
Contact
• Monday, 18 October
• 15:00 16:30
Plenary Presentations: Plenary 1
• 15:00
Opening remarks 15m
Speakers: Tomohiro Uesaka (RIKEN Nishina Center) , yuji goto (riken)
• 15:15
Theory of muon g-2 15m

The longstanding discrepancy between the measured and the predicted values of the anomalous magnetic moment of the muon, $a_\mu$ = (g-2)/2, is one of the most intriguing potential hints of new physics in particle physics. After a brief introduction, the status of the theoretical prediction of g-2 will be presented, with some focus on the contributions yielding the dominant uncertainties. The results presented here are based mainly on the White Paper (arXiv:2006.04822) of the Muon g-2 Theory Initiative.

Speaker: Dr Bogdan MALAESCU (CNRS, LPNHE)
• 15:30
Measurement of muon g-2 30m

At present, there is a discrepancy between the Standard Model calculation and the measured value of the anomalous magnetic moment of the muon $a_\mu$. This disagreement may arise from new physics, or from an omission in either theory or experiment. Ongoing international efforts on both fronts aim to resolve the source of this discrepancy. This talk will present the progress and prospects of precision measurements of $a_\mu$.

Speaker: Vladimir Tishchenko (Brookhaven National Laboratory)
• 16:00
Progress on Lattice QCD studies on the spin physics 30m

Resent results obtained using state-of-the-art lattice QCD simulations on the nucleon spin decomposition will be reviewed. The results include valence and sea quark and gluon contributions. Open issues in particular connected to the fixing and renormalisation will be discussed.

Speaker: Constantia Alexandrou (University of Cyprus and The Cyprus Institute)
• 16:30 16:40
Social (Coffee breaks, Lunch, etc): Coffee break
• 16:40 18:10
Plenary Presentations: Plenary 2
• 16:45
Dipole polarizability from small-angle proton scattering and implications for symmetry energy properties and the formation of neutron skins 30m

The dipole polarizability of nuclei carries information on the density dependence of the symmetry energy governing the properties of the Equation of State of neutron-rich matter relevant to neutron stars and core-collapse supernovae. In recent years, zero-degree polarized proton scattering has been developed at RCNP as an experimental tool to measure the dipole polarizability [1]. Such data also provide constraints on the neutron skin thickness of heavy nuclei [2]. A recent study of $^{40}$Ca together with results from a previous experiment on $^{48}$Ca [3] serve as a test of state-of-the-art ab initio [4,5] and energy densitiy functional [6] calculations. From the good agreement obtained for both methods one can set limits on the density dependence of the symmetry energy. These are clearly at variance with those derived [7] from the recently published result of the PREX-II experiment [8].

[1] P. von Neumann-Cosel and A. Tamii, Eur. Phys. J. A 55, 110 (2019).
[2] A. Tamii et al., Phys. Rev. Lett. 107, 262502 (2011).
[3] J. Birkhan et al., Phys. Rev. Lett. 118, 252501 (2017).
[4] J. Simonis, S. Bacca, and G. Hagen, Eur. Phys. J. A 55, 241 (2019).
[5] S. Kaufmann et al., Phys. Rev. Lett. 124, 132502 (2020).
[6] P.-G. Reinhard, X. Roca-Maza, and W. Nazarewicz, arXiv:2105.15050.
[7] B.T. Reed, F.J. Fattoyev, C.J. Horowitz, and J. Piekarewicz, Phys. Rev. Lett. 126, 172503 (2021).
[8] D. Adhikari et al., Phys. Rev. Lett. 126, 172502 (2021).

Speaker: Peter von Neumann-Cosel (Institut fur Kernphysik, TU Darmstadt)
• 17:15
ELI-NP project overview 25m

Extreme Light Infrastructure - Nuclear Physics (ELI-NP) is a new research infrastructure installed in Bucharest-Magurele (Romania) dedicated to Nuclear Photonics with extreme photon beams. At ELI-NP high-power laser and gamma beams with unprecedented characteristics will be provided to be used for nuclear physics, laser plasma physics, quantum electrodynamics, material science research and related fields.
The high-power laser system consisting of 2 x 10 PW lasers with ultra-short pulses will reach irradiance values as high as 10$^{23}$ W/cm$^2$ and will create ultra-dense, ultra-short, high-energy ion beams as well as coherent X-ray sources. The operation of the laser system at 10 PW has recently marked a world premiere in the field of high-power lasers.
The gamma beams to be delivered at ELI-NP will exhibit high spectral density of about 10$^4$ photons/s/eV, average relative bandwidth of less than 0.5%, continuously tuneable energy up to about 20 MeV, linear polarization of more than 95%.
The experimental setups are currently under commissioning and the first experiments with high-power lasers aim at measuring the magnitude and scaling of the achievable laser intensity via laser-gamma conversion efficiency, finding new ion acceleration schemes and achieving a better understanding and control of high-intensity laser-driven ion sources.
The outstanding characteristics of the gamma beams that will be provided at ELI-NP are opening new perspectives in Nuclear Photonics. Nuclear Resonance Fluorescence experiments will allow for the direct, model-independent determination of key information about the nuclear excited states, such as: excitation energy, spin quantum numbers, parities, branching ratios as well as level widths and gamma decay branching ratios. Photonuclear reactions experiments will largely benefit of the outstanding features of the gamma beams allowing for the study of electromagnetic dipole response of rare nuclei available in nature in extremely low quantities, such as p-nuclei.
A broad research program on technologies for biomedical applications, anchored in the unique ELI-NP capabilities, is currently being developed and addresses topics, such as: production of radiotherapy relevant nuclear beams, radiobiological effects of laser and gamma nuclear beams, medical imaging research with laser X-ray sources and medical isotope production research with laser-driven nuclear beams.
An overview of the ELI-NP research infrastructure and of selected research topics to be investigated at ELI-NP will be given.

Speaker: Dr Calin Alexandru Ur (ELI-NP / IFIN-HH)
• 17:40
Electric Dipole Moment Measurements at Storage Rings 25m

Electric Dipole Moments (EDMs) of elementary particles, including hadrons, are
considered as one of the most powerful tool to study CP-violation beyond the Standard Model.
Such CP-violating mechanisms are searched for to
explain the dominance of matter over anti-matter in our universe.

The talk will discuss EDM searches of charged hadrons in storage rings.
Due to an EDM, the spin vector will experience a torque
resulting in a change of the original spin direction which can be
determined with the help of a polarimeter.
Although the principle of the measurement is simple,
the smallness of the expected effect makes this a challenging experiment
requiring new developments in various experimental areas.
Given the complexity of the project, a step wise approach is proposed$^{1)}$.

The talk will discuss activities at the existing storage ring COSY at Forschungszentrum J\"ulich, Germany.
The next step is the design of a 100\,m circumference prototype ring able to demonstrate
key technologies and components. These include simultaneous clockwise and counter-clockwise beam operation
with electrostatic bending elements and, by adding a magnetic field, the frozen spin technique.
The final step is the operation of a pure electric storage ring of about 500\,m circumference.
Other projects like a measurement of the muon EDM will also be discussed.

$^{1)}$ Storage ring to search for electric dipole moments of charged particles, Feasibility study , CPEDM collaboration, https://doi.org/10.23731/CYRM-2021-003

Speaker: Joerg Pretz (Forschungsyentrum Juelich Germany/RWTH Aachen University)
• 19:00 20:30
Form Factors and GPDs: GPD 1
Conveners: Itaru Nakagawa (RIKEN) , Marie Boer, Prof. Wen-Chen Chang (Institute of Physics, Academia Sinica)
• 19:00
Deeply Virtual Compton Scattering at COMPASS 30m

Deeply Virtual Compton Scattering (DVCS) is the golden exclusive reaction to study Generalized Parton Distributions (GPDs). Such exclusive measurements were performed at COMPASS in 2016 and 2017 at the M2 beamline of the CERN SPS using the 160 GeV muon beam scattering off a 2.5m long liquid hydrogen target surrounded by a barrel-shaped time-of-flight system to detect the recoiling target proton. The scattered muons and the produced real photons were detected by the COMPASS spectrometer, which was supplemented by an additional electromagnetic calorimeter for the detection of large-angle photons.
The DVCS cross section and its dependence with respect to the squared four-momentum transfer are extracted from the sum of cross-sections measured with opposite beam charge and polarization. The goal of the measurement is to determine the transverse extension of the partons in the specific Bjorken x domain of COMPASS between valence quarks and gluons. The analysis method and preliminary results of the long run will be discussed.

Speaker: Dr Nicole d'Hose (IRFU CEA-Université Paris-Saclay)
• 19:30
Spin Density Matrix Elements in Exclusive Muoproduction of $\rho ^0$ and $\omega$ Mesons at COMPASS 20m

We will present results on Spin Density Matrix Elements (SDMEs) measured in hard exclusivsive muoproduction of $\rho ^0$ and $\omega$ mesons on the proton at COMPASS using 160 GeV/$c$ polarised $\mu ^{+}$ and $\mu^{-}$ beams scattering off a liquid
hydrogen target. The measurements cover the range 5 GeV/$c^2$ $< W <$ 17 GeV/$c^2$, 1.0 (GeV/$c$)$^2$ $< Q^2 <$ 10.0 (GeV/$c$)$^2$ and 0.01 (GeV/$c$)$^2$ $< p_T^2 <$ 0.5 (GeV/$c$)$^2$. Here, $Q^2$ denotes the virtuality of exchanged photon, $W$ the mass of final hadronic system and $p_T$ the transverse momentum of the vector meson with respect to the virtual-photon direction. The measured non-zero SDMEs for transitions of transversely polarised virtual photons to longitudinally polarised vector mesons ($\gamma _{T} \rightarrow V_{L}$) indicate a considerable violation of $s$-channel helicity conservation. Additionally, for $\rho ^0$ production we observe a dominant contribution of natural-parity-exchange transitions and a small contribution of
unnatural-parity-exchange transitions observed only at small values of $W$. On the contrary,the contribution of unnatural-parity-exchange for $\omega$ production is significant. It decreases with increasing $W$, being still non-negligible at the largest $W$ values accessible at COMPASS. The results provide an important input for modelling Generalised Parton Distribution (GPDs). In particular, they may allow to evaluate in a model-dependent way the role of parton-helicity flip GPDs ("transversity GPDs") in exclusive $\rho ^0$ and $\omega$ production.

Speaker: Kamil Augsten (Czech Technical University in Prague)
• 19:50
Measurements of the exclusive neutral pion electroproduction at Jefferson Lab Hall A experiment E12-06-114 20m

Generalized Parton Distributions (GPDs) provide a 3D picture of the nucleon by correlating the longitudinal momentum to the transverse position of the partons inside of it. In addition to the chiral-even GPDs, the Deeply Virtual Meson Production (DVMP) also gives access to the chiral-odd (transversity) GPDs and has been providing inputs for the understanding of them. The exclusive production of $\pi^0$, in the Bjorken limit, is expected to be dominated by the contribution of the longitudinally polarized virtual photon that involves only the chiral-even GPDs, but it turned out not to be the case as shown by the previous data with limited reach in $Q^2$. The large contribution from the transversely polarized photon has been suggested to be the consequence of the convolution of the transversity GPDs and the Distribution Amplitudes (DA) of the $\pi^0$. The Jefferson Lab Hall A experiment E12-06-114 extended the kinematic coverage in the quark valence regime, and has measured the cross section of exclusive $\pi^0$ production off protons at large values of $x_B$ (0.36, 0.48, and 0.60) and $Q^2$ (3.1 to 8.4 $\mathrm{GeV^2}$). In this talk, the results of the E12-06-114 measurement will be presented.

Speaker: PO-JU LIN (CEA - Université Paris-Saclay / IJCLab - Orsay)
• 20:10
The deconvolution problem of deeply virtual Compton scattering 20m

Generalised parton distributions are instrumental to study both the three-dimensional structure and the energy-momentum tensor of the nucleon, and motivate numerous experimental programmes involving hard exclusive measurements. Based on a next-to-leading order analysis and a careful study of evolution effects, we exhibit non-trivial generalised parton distributions with arbitrarily small imprints on deeply virtual Compton scattering observables. This means that in practice the reconstruction of generalised parton distributions from measurements, known as the deconvolution problem, does not possess a unique solution for this channel. We further discuss the consequences on the extraction of generalised parton distributions from data and advocate for a multi-channel analysis.

Speaker: Hervé Dutrieux (Irfu, CEA, Université Paris-Saclay)
• 19:00 20:30
Future facilities and experiments
Conveners: Kenichi Nakano (University of Virginia) , Prof. Tanja Horn (The Catholic University of America) , Yuji Goto (RIKEN)
• 19:00 20:30
Polarized Sources and Targets
Conveners: Dr Genki NUKAZUKA (RIKEN BNL Research Center) , Kenichiro Tateishi (RIKEN) , Shunsuke Ikeda (BNL)
• 19:00 20:30
Transverse Momentum Structure (TMD)
Conveners: Prof. Michela Chiosso (University of Torino and INFN) , Ralf Seidl (RIKEN) , Shinsuke Yoshida (Niigata University)
• 20:30 22:00
Acceleration, Storage and Polarimetry of polarized Beams
Conveners: Mitsuhiro Fukuda (RCNP, Osaka University) , Tsutomu Mibe (IPNS/KEK) , Dr Vahid Ranjbar (BNL)
• 20:30 22:00
Form Factors and GPDs: GPD 2
Conveners: Itaru Nakagawa (RIKEN) , Marie Boer, Prof. Wen-Chen Chang (Institute of Physics, Academia Sinica)
• 20:30
Time-like gravitational formfactors and shear viscosity 30m

The extraction of time-like gravitational formfactors from exclusive meson pair production is discussed. The special attention is payed to structures which should cancel between quarks and gluons but may be non-zero for quarks. In particular, dipole term may be associated with shear viscosity. Its studies in exotic hybrid mesons production is addressed. The smallness of the respective GDA may be an analog of smallness of shear viscosity in holographic approach,

Speaker: Oleg Teryaev
• 21:00
Three-loop corrections to the quark and gluon decomposition of the QCD trace anomaly and their applications 20m

In the QCD energy-momentum tensor $T^{\mu\nu}$, the terms that contribute to physical matrix elements are expressed as the sum of the gauge-invariant quark part and gluon part. Each part undergoes the renormalization due to the interactions among quarks and gluons, although the total tensor $T^{\mu\nu}$ is not renormalized thanks to conservation of energy and momentum. We show that, through the renormalization, each of the quark and gluon parts of $T^{\mu\nu}$ receives a definite amount of anomalous trace contribution, such that their sum reproduces the well-known QCD trace anomaly. We provide a procedure to derive such anomalous trace contributions to all orders in perturbation theory, and present the corresponding explicit decomposition formulas up to three-loop order in the (modified) minimal subtraction scheme in the dimensional regularization. We apply our three-loop formulas of the quark/gluon decomposition of the trace anomaly to calculate the anomaly-induced mass structure of nucleons as well as pions. Another application of our three-loop formulas is a quantitative analysis for the constraints on the twist-four gravitational form factors of a hadron, $\bar{C}_{q,g}$, which receive much attention in connection with the force distribution inside the nucleon and the nucleon's transverse spin sum rule. This talk is based on our work, JHEP 1901 (2019) 120, and some additional results.

• 21:20
Accessing pion's large-x gluon by fixed-target charmonium production 20m

The pion, as the Goldstone boson of dynamical chiral symmetry breaking of the strong interaction, is the lightest QCD bound state. Because of its light mass, pion plays a dominant role in the long-range nucleon-nucleon interaction. Understanding the pion’s internal structure is important to investigate the low-energy, non-perturbative aspects of QCD. Nevertheless, the uncertainties of partonic density functions (PDFs) of pions are relatively huge due to lacking rest pion targets.

In this talk, we will review recent theoretical and experimental progress of extracting the pion PDFs. Furthermore, we will provide quantitative evidence within the CEM and NRQCD frameworks that the existing pion-induced fixed-target J/psi data, are sensitive to the gluon density of pions, and favor the pion PDFs with relatively large gluon contents at large x.

References
[1] C.Y. Hsieh, Y.S. Lian, W.C. Chang, J.C. Peng, S. Platchkov, and T. Sawada, Chin. J. Phys. 73, 13 (2021); arXiv:2103.11660.
[2] W.C. Chang, J.C. Peng, S. Platchkov, and T. Sawada, Phys. Rev. D 102, 054024 (2020).Rev. D 99, 014032 (2019); arXiv:2006.06947.

Speaker: Prof. Wen-Chen Chang (Institute of Physics, Academia Sinica)
• 21:40
Exclusive pi0 muoproduction at COMPASS 20m

Hard Exclusive Meson Production and Deeply Virtual Compton Scattering (DVCS) are very promising reactions to study Generalized Parton Distributions (GPDs). Such exclusive measurements were performed at COMPASS in 2016 and 2017 at the M2 beamline of the CERN SPS using the 160 GeV muon beam scattering off a 2.5m long liquid hydrogen target surrounded by a barrel-shaped time-of-flight system to detect the recoiling target proton. The scattered muons and the produced real photons were detected by the COMPASS spectrometer, which was supplemented by an additional electromagnetic calorimeter for the detection of large-angle photons.
Exclusive pi0 production is the main source of background for DVCS measurement, while it provides complementary information for parametrization of GPDs. We will report on preliminary results on exclusive pi0 production cross section and its dependence on the squared four-momentum transfer and on the azimuthal angle between the scattering plane and the pi0 production plane. This reaction is aiming to constrain the GPDs, in particular chiral-odd (“transversity”) GPDs.

• 20:30 22:00
Fundamental Symmetries and and Spin Physics Beyond the Standard Model
Conveners: Hanjie Liu (University of Massachusetts) , Hiroki Nagahama (CNS, The University of Tokyo) , Shinsuke Kawasaki (KEK) , Tsutomu Mibe (IPNS/KEK)
• 20:30 22:00
Spin in Nuclear Reactions and Nuclei
Conveners: Georgi Georgiev (CSNSM/IN2P3/CNRS) , Juzo ZENIHIRO (RIKEN Nishina Center) , Satoshi Sakaguchi (Dept. of Physics, Kyushu University)
• 20:30 22:00
Transverse Momentum Structure (TMD)
Conveners: Prof. Michela Chiosso (University of Torino and INFN) , Ralf Seidl (RIKEN) , Shinsuke Yoshida (South China Normal University)
• Tuesday, 19 October
• 10:30 11:00
Social (Coffee breaks, Lunch, etc): Coffee break
• 15:00 16:40
Plenary Presentations: Pleanry 3
• 15:45
Spin Polarization Effects in Heavy Ion Collisions 30m

itle: Spin polarization effects in Heavy Ion Collisions
Presenter: Zuo-tang Liang (Shandong University)

Abstract:
In non-central high energy heavy ion collisions, the colliding system possesses a huge orbital angular momentum along the normal direction of the reaction plane. Due to the spin orbit interaction in the relativistic quantum system, such a huge orbital angular momentum leads to the spin polarization of quarks and anti-quarks in the quark matter system produced in the collision. Such an effect, known as the global polarization effect (GPE), was predicted many years ago and has been confirmed by the STAR collaboration at RHIC. The discovery of GPE by the STAR collaboration opens a new window in heavy ion physics in general and in studying the properties of quark-gluon plasma in particular. In this talk, I will briefly review the original ideas and calculations that lead to the prediction and summarize progresses and problems in related aspects.

Speaker: Zuo-tang Liang (Shandong University)
• 16:15
Polarized target experiments at LHC 25m

A polarized gaseous target, operated in combination with the high-energy, high-intensity LHC beams and a highly performing LHC particle detector, has the potential to open new physics frontiers and to deepen our understanding of the intricacies of the strong interaction in the non-perturbative regime of QCD. Specifically, the LHCspin project aims to develop, in the next few years, innovative solutions and cutting-edge technologies to access spin physics in high-energy polarized fixed-target collisions using the LHCb detector. Given its forward geometry (2<𝜂<5), the LHCb spectrometer is, in fact, perfectly suitable to cope with the forward kinematics of these collisions. Furthermore, being designed and optimized for the detection of heavy hadrons, it will allow to probe the nucleon’s structure by exploiting new probes, such as inclusive production of c- an b-hadrons, and ideal tool to access, e.g., the essentially unexplored spin-dependent gluon TMDs. This configuration, with center-of-mass energies ranging from 115 GeV in pp interactions to 72 GeV per nucleon in collisions with ion beams, will allow to explore the nucleon’s internal dynamics at unique kinematic conditions, by covering a wide backward rapidity region, including the poorly explored high x-Bjorken and high x-Feynman regimes. This ambitious task poses its basis on the recent installation of SMOG2, a storage-cell based unpolarized gas target in front of the LHCb spectrometer. With the installation of the proposed polarized target system, LHCb will become the first experiment delivering simultaneously unpolarized beam-beam collisions at 14 TeV and both polarized and unpolarized beam-target collisions at center-of-mass energies of the order of 100 GeV. The status of the LHCspin project is presented along with a selection of physics opportunities

Speaker: Dr Luciano Pappalardo (University of Ferrara, Ferrara, Italy)
• 16:40 16:50
Social (Coffee breaks, Lunch, etc): Coffee break
• 16:50 18:20
Plenary Presentations: Plenary 4
• 16:50
Result of the neutron EDM starch at PSI 30m

We report on the result of the neutron EDM experiment which took data in 2015 and 2016 at PSIs ultracold neutron source. The neutron EDM is deemed to be one of the most sensitive probes of physics beyond the standard model. The experiment measured the precession frequency of spin polarized neutrons as a function of a strong electric field. The electric dipole moment of the neutrons leads to a linear dependence between those two quantities. After a blinded data analysis by two independent teams, we concluded that our results do not show this dependence within statistical uncertainties. We thus published a new upper limit of $d_n < 1.8 \,10^{-26} e\, \mathrm{cm}$ [1]. The new result also significantly improves systematic uncertainties which will be discussed in detail. We will also give a future outlook on our new apparatus, n2EDM, which is currently set up at PSI.

[1] C. Abel et al. “Measurement of the Permanent Electric Dipole Moment of the Neutron” Phys. Rev. Lett. 124, 081803 (2020) 10.1103/PhysRevLett.124.081803.

Speaker: Georg Bison (Paul Scherrer Institut)
• 19:00 20:30
Joint BSM - Accelerator - Future Session EU timezone
Conveners: Hanjie Liu (University of Massachusetts) , Hiroki Nagahama (CNS, The University of Tokyo) , Kenichi Nakano (University of Virginia) , Mitsuhiro Fukuda (RCNP, Osaka University) , Shinsuke Kawasaki (KEK) , Prof. Tanja Horn (The Catholic University of America) , Tsutomu Mibe (IPNS/KEK) , Dr Vahid Ranjbar (BNL)
• 19:00 20:30
Nucleon Helicity Structure: Helicity 1
Conveners: Itaru Nakagawa (RIKEN) , Maria Zurek (Argonne National Laboratory)
• 19:00
Illuminating the nucleon spin 30m

I will discuss the extension of the nucleon spin sum rule to QCDxQED. I will present the QED corrections to the evolution of the quark and gluon helicity and orbital-angular-momentum (OAM) distributions, which are calculated for the first time, and the necessary inclusion of photon and lepton helicity and OAM distributions.

Speaker: Miguel Echevarria (Universidad de Alcalá)
• 19:30
Useful relations and sum rules for PDFs and multiparton distribution functions of spin-1 hadrons 20m

Sum rules for structure functions and their twist-2 relations have important roles in constraining their magnitudes and $x$ dependencies and in studying higher-twist effects. The Wandzura-Wilczek (WW) relation and the Burkhardt-Cottingham (BC) sum rule are such examples for the polarized structure functions $g_1$ and $g_2$. Recently, new twist-3 and twist-4 parton distribution functions were proposed for spin-1 hadrons, so that it became possible to investigate spin-1 structure functions including higher-twist ones. We show in this work that an analogous twist-2 relation and a sum rule exist for the tensor-polarized parton distribution functions $f_{1LL}$ and $f_{LT}$, where $f_{1LL}$ is a twist-2 function and $f_{LT}$ is a twist-3 one. Namely, the twist-2 part of $f_{LT}$ is expressed by an integral of $f_{1LL}$ (or $b_1$) and the integral of the function $f_{2LT} = (2/3) f_{LT} -f_{1LL}$ over $x$ vanishes. If the parton-model sum rule for $f_{1LL}$ ($b_1$) is applied by assuming vanishing tensor-polarized antiquark distributions, another sum rule also exists for $f_{LT}$ itself. These relations should be valuable for studying tensor-polarized distribution functions of spin-1 hadrons and for separating twist-2 components from higher-twist terms, as the WW relation and BC sum rule have been used for investigating $x$ dependence and higher-twist effects in $g_2$. In deriving these relations, we indicate that four twist-3 multiparton distribution functions $F_{LT}$, $G_{LT}$, $H_{LL}^\perp$, and $H_{TT}$ exist for tensor-polarized spin-1 hadrons. These multiparton distribution functions are also interesting to probe multiparton correlations in spin-1 hadrons.

Speaker: Qin-Tao Song (Zhengzhou University)
• 19:50
Helicity quasi-PDFs in a large Nc nucleon 20m

We discuss the properties of the helicity quark quasi-distributions in the large Nc limit. Within the framework of the chiral quark-soliton model, we review the properties of the quasi-PDFs such as the sum rules and the positivity. Numerical results for quark and antiquark isovector helicity distributions are presented. Significant antiquark flavor asymmetry is observed in a wide range of nucleon momentum.

Speaker: Hyeon-Dong Son (Ruhr-University Bochum)
• 19:00 20:30
Polarized Sources and Targets
Conveners: Dr Genki NUKAZUKA (RIKEN BNL Research Center) , Kenichiro Tateishi (RIKEN) , Shunsuke Ikeda (BNL)
• 19:00 20:30
Transverse Momentum Structure (TMD)
Conveners: Prof. Michela Chiosso (University of Torino and INFN) , Ralf Seidl (RIKEN) , Shinsuke Yoshida (South China Normal University)
• 20:30 22:00
Acceleration, Storage and Polarimetry of polarized Beams
Conveners: Mitsuhiro Fukuda (RCNP, Osaka University) , Tsutomu Mibe (IPNS/KEK) , Dr Vahid Ranjbar (BNL)
• 20:30 22:00
Applications of Nuclear Polarization in other Fields
Conveners: Kenichiro Tateishi (RIKEN) , Patrick Hautle (Paul Scherrer Institute) , Takayuki KUMADA (Japan Atomic Energy Agency)
• 20:30 22:00
Fundamental Symmetries and and Spin Physics Beyond the Standard Model
Conveners: Hanjie Liu (University of Massachusetts) , Hiroki Nagahama (CNS, The University of Tokyo) , Shinsuke Kawasaki (KEK) , Tsutomu Mibe (IPNS/KEK)
• 20:30 22:00
Joint TMD - GPD - HELCITY - Future session EU timezone
Conveners: Itaru Nakagawa (RIKEN) , Kenichi Nakano (University of Virginia) , Maria Zurek (Argonne National Laboratory) , Marie Boer, Prof. Michela Chiosso (University of Torino and INFN) , Shinsuke Yoshida (South China Normal University) , Prof. Tanja Horn (The Catholic University of America) , Prof. Wen-Chen Chang (Institute of Physics, Academia Sinica) , Yuji Goto (RIKEN)
• Wednesday, 20 October
• 09:00 10:45
Plenary Presentations: Plenary 5
• 10:15
Crystallography of Dynamically Polarized Proteins with Polarized Neutron Beams 30m

Protein crystallography is an established technique for determining the structure of many protein systems. X-ray protein crystallography is the dominant technique, as the incredibly high flux of modern light sources allows researchers to collect data very quickly using very small crystals. In comparison, neutron crystallography has many unique advantages (due the neutron’s sensitivity to isotopes and light nuclei) but suffers from the low flux available at neutron sources. The spin dependence of slow neutron scattering provides an opportunity to overcome the flux limitations of neutron sources, expanding the number of protein systems that can be studied, improving the signal to noise, and enabling novel measurement techniques to determine the location of hydrogen atoms. At Oak Ridge National Laboratory, a program has been underway to develop Dynamic Nuclear Polarization (DNP) techniques, and apply them to neutron scattering, especially Neutron Macromolecular Crystallography of proteins. The status and results of the Dynamic Nuclear Polarization program at Oak Ridge National Laboratory will be discussed, with an emphasis on the use of DNP to enhance measurements of diffraction from protein crystals.

Speaker: Josh Pierce (Oak Ridge National Laboratory)
• 10:45 11:00
Social (Coffee breaks, Lunch, etc): Coffee break
• 11:00 12:30
Fundamental Symmetries and and Spin Physics Beyond the Standard Model
Conveners: Hanjie Liu (University of Massachusetts) , Hiroki Nagahama (CNS, The University of Tokyo) , Shinsuke Kawasaki (KEK) , Tsutomu Mibe (IPNS/KEK)
• 11:00 12:30
Nucleon Helicity Structure: Helicity 2
Conveners: Itaru Nakagawa (RIKEN) , Maria Zurek (Argonne National Laboratory)
• 11:00
Measurement of the anti-quark flavor asymmetry in the proton at FNAL-SeaQuest 30m

The flavor asymmetry of the unpolarized distributions of light anti-quarks (i.e. $\bar{u}(x)$ and $\bar{d}(x)$) in the proton was observed by several deep-inelastic muon scattering experiments. The ratio $\bar{d}(x)/\bar{u}(x)$ was measured by Drell-Yan experiments NA51 at CERN and E866 at Fermilab and a large asymmetry was reported.

The mechanism of this asymmetry has been studied via various theoretical models. The asymmetry of unpolarized distributions can be correlated with that of helicity distributions, e.g. the statistical model predicts the similar magnitude with the opposite sign; $\bar{d}(x) - \bar{u}(x) \approx - \left(\Delta\bar{d}(x) - \Delta\bar{u}(x)\right)$. Therefore a comparison between the unpolarized and helicity distributions of the sea quarks is appropriate.

SeaQuest at Fermilab is a fixed-target experiment designed to detect the Drell-Yan process in $p+p$ and $p+d$ reactions. The goal is to measure precisely the ratio $\bar{d}(x)/\bar{u}(x)$ in a wide Bjorken $x$ region up to 0.45. Results from SeaQuest on the anti-quark flavor asymmetry will be presented.

Speaker: Kenichi Nakano (University of Virginia)
• 11:30
Measurement of longitudinal spin transfer of the $\Lambda(\bar{\Lambda})$ hyperon in longitudinally polarized $\rm{p}$$+$$\rm{p}$ collisions at $\sqrt{s}=200$ $\rm{GeV}$ at RHIC-STAR 20m

Since the first surprising results on the spin structure of the proton by the EMC experiment in the late 1980s, much progress has been made in understanding the origin of the proton spin. However, the sea quark contribution to the proton spin, for example, the helicity distributions of the strange quark (anti-quark), $s(\bar{s})$, is still not well constrained by experimental data. Since the $s(\bar{s})$ is expected to carry a substantial fraction of the spin of the $\Lambda(\bar{\Lambda})$ hyperon, measurements of the longitudinal spin transfer, $D_{LL}$, of the $\Lambda(\bar{\Lambda}$) hyperon can thus shed light on the helicity distribution of the $s(\bar{s})$ and the longitudinally polarized fragmentation functions. In this talk, we will present the status of the $\Lambda(\bar{\Lambda}$) $D_{LL}$ analysis using data collected at RHIC-STAR in 2015, for the pseudo-rapidity $|\eta| < 1.2$ and transverse momenta up to $8.0$ $\rm{GeV}$$/c$. The $D_{LL}$ as a function of the longitudinal momentum fraction of the $\Lambda(\bar{\Lambda})$ hyperon in the jet is also investigated. This data set is about twice as large as the 2009 data used for the previously published $D_{LL}$ results.In addition, the longitudinal double spin asymmetries, $A_{LL}$, of the $\Lambda(\bar{\Lambda})$ hyperon and the $K_{S}^{0}$ meson are investigated, which are also expected to be sensitive to the $s(\bar{s})$ helicity distributions.

• 11:50
Studies of Neutral Current Neutrino-Nucleon Scattering with the MicroBooNE Detector 20m

The MicroBooNE experiment is an 85 ton active volume liquid-argon time projection chamber (LArTPC) located in the Booster Neutrino Beamline at Fermilab. The excellent calorimetric and spatial resolution of the LArTPC allows us to identify isolated proton tracks with lengths as short as 2 cm, which is equivalent to proton kinetic energy T = 50 MeV. We report the progress towards the first measurement of muon neutrino neutral current elastic scattering from protons in Argon in the region of four-momentum transfer squared, $0.1 < Q^2< 1$ GeV$^2$, using MicroBooNE's 6.87$\times 10^{20}$ POT data. We also present our plan to extract the strange quark contribution to the axial form factor, which is crucial for understanding the strange quark contribution to the proton spin.

• 12:10
Collinear twist-3 approach to hyperon polarization in SIDIS 20m

We discuss the production of transversely polarized hyperons in semi-inclusive deep inelastic scattering in the framework of the collinear twist-3 factorization. In this framework, the twist-3 cross section consists of three contributions depending on the origins for the polarizations: (i) Twist-3 distribution in the initial proton combined with the twist-2 transversity fragmentation function (FF) for the final hyperon, (ii) Twist-3 quark FF for the hyperon and (iii) Twist-3 gluon FF for the hyperon. In this talk. we focus on the first two contributions, since they are expected to become dominant contribution. We present the twist-3 cross section in the leading order (LO) with respect to the QCD coupling constant for all the five structure functions which have different dependences on the azimuthal angles. We also discuss the matching with the TMD framework in the small-$P_T$ region. The present result is important for the future EIC experiment.

• 11:00 12:30
Transverse Momentum Structure (TMD)
Conveners: Prof. Michela Chiosso (University of Torino and INFN) , Ralf Seidl (RIKEN) , Shinsuke Yoshida (South China Normal University)
• 16:30 18:00
Joint GPD - Future session
Conveners: Itaru Nakagawa (RIKEN) , Kenichi Nakano (University of Virginia) , Marie Boer, Prof. Tanja Horn (The Catholic University of America) , Prof. Wen-Chen Chang (Institute of Physics, Academia Sinica) , Yuji Goto (RIKEN)
• 16:30
Phenomenological assessment of proton mechanical properties from deeply virtual Compton scattering 30m

A unique feature of generalised parton distributions is their relation to the QCD energy–momentum tensor. In particular, they provide access to the mechanical properties of the proton i.e. the distributions of pressure and shear stress induced by its quark and gluon structure. In principle the pressure distribution can be experimentally determined in a model-independent way from a dispersive analysis of deeply virtual Compton scattering data through the measurement of the subtraction constant. In practice the kinematic coverage and accuracy of existing experimental data make this endeavour a challenge. Elaborating on recent global fits of deeply virtual Compton scattering measurements using artificial neural networks, our analysis presents the current knowledge on this subtraction constant and assesses the impact of the most frequent systematic assumptions made in this field of research. This study will pave the way for future works when more precise data will become available, e.g. obtained in the foreseen electron-ion colliders EIC and EIcC.

• 17:00
Exclusive production of Quarkonia and Heavy Flavors to access gluon Generalized Parton Distributions at EIC 20m

Exclusive heavy meson production is a key tool for accessing the inner dynamics of the proton. These reactions involve the proton Generalized Parton Distributions (GPDs), which correlate the longitudinal momenta and their transverse distribution of the proton’s composite partons. The hard exclusive production of Quarkonia ($J/\psi$, $\Upsilon$, etc.) is particularly interesting, as it accesses the gluon GPDs at the lowest order. We used ROOT to create a new flexible generator for the photoproduction, quasi-photoproduction, and electroproduction of vector mesons off a proton. The output phase space is weighted by the reaction cross-section, creating a realistic graph of event count as a function of kinematics. We will discuss the relevance of measuring hard exclusive production of Quarkonia, present our work on the event generator, and discuss our projections for the upcoming Electron-Ion Collider (EIC).

Speaker: Tyler Schroeder
• 17:20
Artificial neural network techniques in modelling of GPDs 20m

We discuss the use of machine learning techniques for the modeling of generalized parton distributions in view of their nonparametric estimation from experimental data. Current GPD extractions indeed suffer from a model dependence which lessens their impact and brings unknown systematics in the estimation of derived quantities like 3D tomography or angular momentum decomposition. On the contrary this new strategy to describe GPDs allows a flexible implementation of theory driven constraints and provides tools to keep model dependence at a minimum level. We also address aspects of a practical nature like the design and training of artificial neural networks suitable for this analysis. Getting a better grip on the control of systematic effects, our work will help GPD phenomenology to achieve its maturity in the precision era of GPD extractions opened by a new generation of experiments.

Speaker: Paweł Sznajder (National Centre for Nuclear Research)
• 17:40
Accessing pion GPDs through the Sullivan process: is it feasible? 20m

The description of hadronic structure in terms of quark and gluon degrees of freedom is an open subject in physics. Great efforts are being devoted to this subject on both the theoretical and experimental sides. Triggered by existing plans to build new experimental facilities such as the EIC (BNL), and the need to properly interpret the data that are to come, the theoretical interest into the zoology of parton distribution functions is increasing. Among them, GPDs, which are known to parametrize the soft-physics taking place in DVCS, are expected to play a central role drawing three-dimensional images of hadrons. In this work we focus on the study of pions which, as Nambu-Goldstone bosons of QCD chiral symmetry breaking, provide one of the clearest windows onto the phenomenon of emergent hadronic mass (EHM). Herein we present a novel class of pion off-forward parton distributions: the so called postitivity-saturated GPDs, which relying on the covariant-extension fulfill all of the theoretical constraints required by QCD and benefit from a direct interpretation in terms of fundamental degrees of freedom: quarks and gluons. Exploiting them we are capable to obtain predictions for DVCS on pions to be probed through the Sullivan process at the EIC. We will show that a measurable asymmetry on the channel arise, therefore pushing optimism about probing pion structure at future electron-ion colliders.

• 16:30 18:00
Spin in Nuclear Reactions and Nuclei
Conveners: Georgi Georgiev (CSNSM/IN2P3/CNRS) , Juzo ZENIHIRO (RIKEN Nishina Center) , Satoshi Sakaguchi (Dept. of Physics, Kyushu University)
• 16:30 18:00
Transverse Momentum Structure (TMD)
Conveners: Prof. Michela Chiosso (University of Torino and INFN) , Ralf Seidl (RIKEN) , Shinsuke Yoshida (South China Normal University)
• 18:30 20:00
Plenary Presentations: Plenary 6
• 19:05
Experimental studies on the high-energy spin physics in collider experiments at RHIC 30m

The Relativistic Heavy Ion Collider (RHIC) is the world’s only polarized proton+proton collider, capable of reaching center of mass energies up to 510 GeV. RHIC's experiments, PHENIX and STAR, have been carrying out a cold QCD program in order to gain deeper insight into the proton's spin structure and dynamics.
Data from longitudinally polarized $p+p$ collisions allow one to study the gluon helicity distribution function ($\Delta g(x)$), by measuring the longitudinal double-spin asymmetry ($A_{LL}$) of pions and jets. On the other side, the transversely polarized proton collisions at RHIC enable the studies of the transverse spin structure, such as the transversity and Sivers distributions, as well as polarized fragmentation functions. These studies can be used to test universality of transverse-momentum dependent distributions (TMDs) with respect to $e$+$p$ processes, and constrain their evolution effects. Furthermore, unpolarized measurements of differential cross sections of weak bosons at RHIC provide important constraints on the scale dependence of unpolarized TMDs in an $x$ range ($0.1 < x < 0.3$) that naturally complements the phase space accessed at the LHC.
In this talk, we present the recent measurements for longitudinal and transverse polarization, besides selected unpolarized results. PHENIX newly redesigned detector, sPHENIX is being installed while STAR is currently installing a suite of new sub detectors in the forward region ($2.5 < \eta < 4$). How those upgrades will supplement previous Spin measurements at RHIC will also be briefly discussed.

Speaker: Salvatore Fazio (University of Calabria & INFN Cosenza - Italy)
• Thursday, 21 October
• 07:00 08:30
Acceleration, Storage and Polarimetry of polarized Beams
Conveners: Mitsuhiro Fukuda (RCNP, Osaka University) , Tsutomu Mibe (IPNS/KEK) , Dr Vahid Ranjbar (BNL)
• 07:00 08:30
Fundamental Symmetries and and Spin Physics Beyond the Standard Model
Conveners: Hanjie Liu (University of Massachusetts) , Hiroki Nagahama (CNS, The University of Tokyo) , Shinsuke Kawasaki (KEK) , Tsutomu Mibe (IPNS/KEK)
• 07:00 08:30
Joint TMD - GPD - HELCITY - Future session US timezone
Conveners: Itaru Nakagawa (RIKEN) , Kenichi Nakano (University of Virginia) , Maria Zurek (Argonne National Laboratory) , Marie Boer, Prof. Michela Chiosso (University of Torino and INFN) , Shinsuke Yoshida (South China Normal University) , Prof. Tanja Horn (The Catholic University of America) , Prof. Wen-Chen Chang (Institute of Physics, Academia Sinica) , Yuji Goto (RIKEN)
• 07:00 08:30
Low energy spin physics with lepton, photon and hadron probes
Conveners: Atsushi Tamii (Research Center for Nuclear Physics) , Hideki Kohri (RCNP, Osaka University)
• 08:30 10:00
Future facilities and experiments
Conveners: Kenichi Nakano (University of Virginia) , Prof. Tanja Horn (The Catholic University of America) , Yuji Goto (RIKEN)
• 08:30 10:00
Joint GPD - Helicity session
Conveners: Itaru Nakagawa (RIKEN) , Maria Zurek (Argonne National Laboratory) , Marie Boer, Prof. Wen-Chen Chang (Institute of Physics, Academia Sinica)
• 08:30
transverse spin sum rules 30m

There are two transverse spin sum rules for the proton: One involves twist-2 GPDs, which has a partonic interpretation, and the other involves twist-3 distributions including the well-know spin structure function g_2. I will explain the origin and physics of these two spin sum rules.

Speaker: Prof. XIANGDONG JI (University of Maryland)
• 09:00
Novel CFFs Extraction in Unpolarized DVCS 20m

Over the last 20 years there has been intense experimental activity dedicated to the measurement of observables to help build a 3D description of the nucleon. Generalized parton distributions (GPDs) describe complementary aspects of the structure of hadrons, providing qualitative and quantitative information about the partonic structure and dynamics such as orbital angular momentum. The formulation of the DVCS cross section is parametrized in terms of Compton Form Factors (CFFs) which are convolutions of GPDs with coefficient functions computed from perturbative QCD.This talk presents the most recent DVCS helicity amplitude formulations aimed at extracting CFFs and explores their distinctive kinematic characteristics.

• 09:20
Longitudinal Spin Transfer to Lambda Hyperons in CLAS12 20m

Using the self analyzing decay of the $\Lambda^0$, the longitudinal spin transfer $D_{LL}$ from a polarized electron beam scattering an unpolarized proton target to the hyperon can be measured. For $\Lambda$'s produced in the current fragmentation region, this quantity is proportional to the helicity dependent fragmentation function $G_1^\Lambda$ and can provide insight into the spin structure of the $\Lambda^0$. Currently, experimental data on $D_{LL}$ is limited and is not able to discriminate between different models of the $\Lambda^0$ spin structure. This contribution will report the status of the ongoing analysis of the longitudinal spin transfer using data taken by the CLAS12 experiment at Jefferson Lab, a large acceptance spectrometer using a 10.6 GeV electron beam. A focus of the analysis will be on the use of Graph Neural Networks (GNNs) to identify signal events.

• 08:30 10:00
Polarized Sources and Targets
Conveners: Dr Genki NUKAZUKA (RIKEN BNL Research Center) , Kenichiro Tateishi (RIKEN) , Shunsuke Ikeda (BNL)
• 08:30 10:00
Transverse Momentum Structure (TMD)
Conveners: Prof. Michela Chiosso (University of Torino and INFN) , Ralf Seidl (RIKEN) , Shinsuke Yoshida (South China Normal University)
• 10:30 11:00
Social (Coffee breaks, Lunch, etc): Coffee break
• 11:00 12:30
Plenary Presentations: Plenary 7
• 11:30
T-violation in neutron scattering 30m

The fundamental symmetry violation can be studied by using nuclear reactions with polarized neutrons beam and target nuclei. The large enhancement of the parity violation was observed in the neutron capture reactions for some nuclei. It is predicted that time reversal symmetry violation is also enhanced with the same mechanism. Our recent results of 139La(n, γ) reaction suggested that the enhancement is large enough to search T-violation with high sensitivity, which can be reach to the sensitivity of neutron electric dipole moment and which has different systematics. We are performing the research and development for the T-violation search experiment at J-PARC, for example, details of nuclear reactions with candidate nuclei and that of experimental setup. We are also developing the polarization technique for both of neutron beam and target nuclei, so-called spin exchange optical pumping and dynamic nuclear polarization, respectively.

Speaker: Masaaki Kitaguchi (Nagoya University)
• 12:00
Progress on fragmentation-function studies 30m

In recent years, significant progress has been made in improving our understanding of the QCD fragmentation process. I will review theoretical and experimental advances that can shed new light on both collinear and Transverse Momentum Dependent (TMD) fragmentation. Examples include new extractions of fragmentation functions, hadron-in-jet fragmentation, and multi-differential measurements. In addition, I will review spin-polarized observables in electron-positron annihilation, proton-proton collisions and at the future Electron-Ion Collider.

Speaker: Felix Ringer (LBNL)
• 12:40 14:25
Plenary Presentations: Plenary 8
• 13:30
Spin Physics Detector at NICA 25m

The Spin Physics Detector (SPD) is one of the two large setups at the
NICA collider under construction at JINR (Dubna). The ultimate goal of
the studies at SPD is measurement of different spin observables in
polarized proton-proton, deuteron-deuteron and proton-deuteron
collisions sensitive to the polarized gluonic structure of the nucleon
at the luminosity up to 10^32 cm^-2*s^-1 and \sqrt{s} up to 27 GeV.
SPD will consist of the superconducting magnetic system, silicon
tracker based on the DSSD and MAPS technologies, straw mini-drift
tubes tracker, time-of-flight system, electromagnetic «shashlyk»-type
calorimeter, muon (range) and local-polarimetry systems. The high
performance free-streaming DAQ system will be able to operate at the
collision rate up to 4 MHz.

• 13:55
Nuclear spin-isospin responses studied by nuclear reactions: A tribute to Munetake Ichimura 25m

Progress in the nuclear spin physics studied by nuclear reactions is briefly reviewed with particular emphasis on the contributions of Munetake Ichimura and his research-group.
Much of his recent work was based on a comprehensive framework consisting of a distorted wave impulse approximation (DWIA) with response function calculated by a continuum random phase approximation(RPA).
We pay special attention to two contrasting problem.
One is the quenching of the total Gamow-Teller (GT) transition strength with respect to the model-independent GT sum rule (Ikeda's sum rule).
The other is the enhancement of the pionic modes at relative large momentum transfers as a precursor phenomenon of pion condensation.
A main aim of this review is to gain an overall understanding of the behavior of these spin-isospin modes.
Furthermore, recent developments in the isospin dependence of the spin-isospin residual interaction studied by the GT resonances for unstable nuclei as well as the tensor correlation effects observed in the spin-dipole resonances are also addressed.

Speaker: Tomotsugu Wakasa (Kyushu University)
• 15:30 16:00
Social (Coffee breaks, Lunch, etc): Coffee break
• Friday, 22 October
• 07:00 08:30
Future facilities and experiments
Conveners: Kenichi Nakano (University of Virginia) , Prof. Tanja Horn (The Catholic University of America) , Yuji Goto (RIKEN)
• 07:00 08:30
Nucleon Helicity Structure: Helicity 3
• 07:00
Small-x Helicity Evolution and the Proton Spin Puzzle 30m

We report on the first phenomenological analysis of the world polarized deep-inelastic scattering (DIS) data incorporating small-x helicity (Kovchegov-Pitonyak-Sievert) evolution. This framework allows for one to predict the behavior of helicity parton distribution functions (PDFs) down to very low x. Consequently, one can control the uncertainties in these functions beyond the measured region and make precise calculations of the integrals needed to determine the contribution of quark and gluon spin to the proton spin. Therefore, the small-x helicity formalism will play a crucial role in using future Electron-Ion Collider data to resolve the proton spin puzzle.

Speaker: Dr Daniel Pitonyak
• 07:30
First Extraction of Polarized Sea Asymmetry from Weak Boson Production in Proton-Proton Collisions 20m

We present the first global QCD analysis of helicity parton distribution functions (PDFs) to include the latest polarized $W$-lepton production data from the STAR collaboration at the Relativistic Heavy-Ion Collider. This data allows the first extraction of a nonzero helicity light quark sea asymmetry within a global QCD analysis. By performing a simultaneous extraction of the unpolarized and helicity PDFs, we are also able to extract for the first time in a self-consistent manner the polarizations of the light sea quarks $\Delta \bar{u}/\bar{u}$ and $\Delta \bar{d}/\bar{d}$.

• 07:50
J/psi spin asymmetry measurements in p+p collisions at 200 and 510 GeV by the PHENIX experiment at RHIC 20m

Studies of heavy quark bound states, like J/psi meson, provide a useful tool to investigate QCD properties. Many general features of J/psi production, such as cross-sections and transverse momentum distributions are well described by many existing models. In order to differentiate between various theoretical models one has to study J/psi production in more details. One of the observables which can be used for this purpose is angular distribution of leptons produced in quarkonium decays, usually called polarization or spin asymmetry.
The PHENIX experiment at RHIC has measured inclusive J/psi polar and azimuthal angular decay coefficients at the mid (|y|<0.35) and forward (1.2<|y|<2.2) rapidity in p+p collisions at 200 GeV and 510 GeV. In this talk the analysis details as well as the results in different polarization frames will be presented and compared to theory.

Speaker: alexandre lebedev (Iowa State University)
• 07:00 08:30
Spin in Nuclear Reactions and Nuclei
Conveners: Georgi Georgiev (CSNSM/IN2P3/CNRS) , Juzo ZENIHIRO (RIKEN Nishina Center) , Satoshi Sakaguchi (Dept. of Physics, Kyushu University)
• 07:00 08:30
Transverse Momentum Structure (TMD): TMD 7
Conveners: Prof. Michela Chiosso (University of Torino and INFN) , Ralf Seidl (RIKEN) , Shinsuke Yoshida (South China Normal University)
• 08:30 10:00
Acceleration, Storage and Polarimetry of polarized Beams
Conveners: Mitsuhiro Fukuda (RCNP, Osaka University) , Tsutomu Mibe (IPNS/KEK) , Dr Vahid Ranjbar (BNL)
• 08:30 10:00
Joint BSM - Lowenergy - Future Session US timezone
Conveners: Atsushi Tamii (Research Center for Nuclear Physics) , Hanjie Liu (University of Massachusetts) , Hideki Kohri (RCNP, Osaka University) , Hiroki Nagahama (CNS, The University of Tokyo) , Kenichi Nakano (University of Virginia) , Shinsuke Kawasaki (KEK) , Prof. Tanja Horn (The Catholic University of America) , Tsutomu Mibe (IPNS/KEK) , Yuji Goto (RIKEN)
• 08:30 10:00
Nucleon Helicity Structure: Helicity 4
• 08:30
The role of the chiral anomaly in polarized deeply inelastic scattering: Topological screening and emergent axion-like dynamics 30m

I’ll discuss the role of the chiral anomaly in deep inelastic scattering (DIS) of electrons off polarized protons employing a worldline formalism, which is a powerful framework for the computation of perturbative multi-leg Feynman amplitudes. I’ll demonstrate how the triangle anomaly appears at high energies in the DIS box diagram for the polarized structure function $g_1(x_B,Q^2)$ in both the Bjorken limit of large $Q^2$ and in the Regge limit of small $x_B$. I’ll show that the infrared pole of the anomaly appears in both limits. I will introduce an effective action for spin dependent observables at small x that follows from the cancellation of the infrared pole in the matrix element of the anomaly. This effective action, consistent with anomalous chiral Ward identities, is controlled by two dimensionful scales in Regge asymptotics. The first is the color charge squared per unit area, while the second is the pure Yang-Mills topological susceptibility.

Speaker: Dr Andrey Tarasov (The Ohio State University)
• 09:00
Measurement of Direct Photon Cross Section and Double Helicity Asymmetry at $\sqrt{s}$ = 510 GeV in $\vec{p}+\vec{p}$ Collisions at PHENIX 20m

The proton spin decomposition provides key information about the structure of the nucleons. Since late 1980s, experiments showed that the quark spin contributes only $\sim$30\% to the proton spin, with remaining part coming from gluon spin as well as quark and gluon orbital angular momentum. While the quark spin contribution was better constrained by polarized deep inelastic scattering (DIS), the gluon spin contribution remains less known, because it is probed through higher order processes (suppressed by $\sim$0.2 comparing to leading order processes) in DIS. The Relativistic Heavy Ion Collider (RHIC) is the only collider capable of producing two longitudinal polarized proton ($\vec{p}+\vec{p}$) beams. Direct photon, jet and charged pion productions in $\vec{p}+\vec{p}$ collisions can probe the gluon spin at leading order. Comparing with hadron productions, direct photon production is the most clean'' channel, since there is little fragmentation involved, and is considered thegolden'' channel. However, the relatively small direct photon cross section compared to the hadron productions made it a challenging observable, until the RHIC 2013 run, which provides the largest integrated luminosity (155 pb$^{-1}$) in $\vec{p}+\vec{p}$. In addition, the Electromagnetic Calorimeter at PHENIX has fine granularity to separate the two $\pi^0$ decay photons up to $\pi^0$ transverse momentum $p_T$ of 12 GeV/c, and a shower profile analysis extends the $\gamma/\pi^0$ discrimination to beyond 20 GeV/c. These conditions finally made this golden'' measurement come to reality. In this talk, I will present the isolated and inclusive direct photon cross sections and their ratio for photon $p_T$ of 6--30 GeV/c, as well as the isolated direct photon double helicity asymmetry ($A_{LL}$) for photon $p_T$ of 6--20 GeV/c. When included in global analyses in the future, our results will provide an independent constraint on the gluon spin contribution to the proton spin.

Speaker: Mr Zhongling Ji (Stony Brook University)
• 09:20
Recent Longitudinal Spin Results with Charged Pions and Jets at PHENIX 20m

Operated at the Relativistic Heavy Ion Collider at Brookhaven until beginning its recent upgrade into sPHENIX, the PHENIX experiment has collected a wealth of data from polarized proton collisions. Analysis of these data sets continues to offer insight into the spin structure of the proton. In particular, RHIC's polarized proton-proton data help constrain polarized PDFs in the proton, and the double spin asymmetry of various processes is sensitive to gluons at leading order. I will give a brief overview of the detector and recent results in charged pion and jet asymmetries, as well as a discussion of the impact these measurements have on our understanding of parton polarizations.

• 09:40
Constraining the Polarized Gluon Distribution Function of the Proton with Recent STAR Measurements 20m

The contribution of the gluon spin to the spin of the proton is being studied through the use of the unique capability of the Relativistic Heavy Ion Collider (RHIC) to collide longitudinally polarized protons at $\sqrt{s}=200\,$GeV and $\sqrt{s}=510\,$GeV. The kinematic coverage of the Solenoidal Tracker At RHIC (STAR) allows access to gluons through quark-gluon and gluon-gluon scattering processes which dominate particle production at low and medium transverse momentum. The polarized gluon distribution function, $\Delta g(x)$, can be constrained through global analyses of the longitudinal double-spin asymmetries ($A_{LL}$) of inclusive jet and di-jet production.

Published inclusive jet results from 2009 data at mid-rapidity ($|\eta| < 1$ ) at $\sqrt{s}=200\,$GeV have been included in global analyses and suggest a significant non-zero truncated first moment of $\Delta g(x)$ for $x>0.05$. An additional data sample of $43\,$pb$^{-1}$ has been collected in 2015 at the same collision energy. This new data sample is over twice as large as the previous sample, providing an opportunity to improve the precision of $\Delta g(x)$ for $x>0.05$. The published results from the analysis of the 2015 data will be presented along with the status of the analysis using a large data sample of $250\,$pb$^{-1}$ collected at $\sqrt{s}=510\,$GeV in 2013.

• 08:30 10:00
Polarized Sources and Targets
Conveners: Dr Genki NUKAZUKA (RIKEN BNL Research Center) , Kenichiro Tateishi (RIKEN) , Shunsuke Ikeda (BNL)
• 08:30 10:00
Transverse Momentum Structure (TMD): TMD 8
Conveners: Prof. Michela Chiosso (University of Torino and INFN) , Ralf Seidl (RIKEN) , Shinsuke Yoshida (South China Normal University)
• 10:30 11:00
Social (Coffee breaks, Lunch, etc): Coffee break
• 11:00 12:30
Plenary Presentations: Plenary 9
• 11:30
LEPS experiments with polarized photons 30m

A linearly polarized photon beam acts as a filter to disentangle the production mechanisms and suppress background processes in the photoproduction of mesons and baryons. Compton backscattering of laser light off the 8 GeV electrons circulating in the SPring-8 storage ring provides a high-intensity beam of linearly polarized photons in a range of $1.4$ - $2.9$ GeV. The LEPS facility featured a large dipole spectrometer and operated in the last 20 years. LEPS data encompasses final states produced forward, such as $K^+$, $K^\ast$, and $\phi$ from photoproduction and manifested in experimental observables such as the cross-section and beam asymmetry. In addition, associated hyperon production with $K^\ast$ is fascinating to unveil the nature of $\Lambda(1405)$. The LEPS2 facility, consisting of a large solenoid magnet and a time projection chamber, has recently completed its first phase of beam commissioning and physics running. Analysis effort of the first dataset is now underway. We will present selected recent highlights with LEPS and the prospects of the LEPS2 facility.

Speaker: Prof. Jung Keun Ahn (Korea University)
• 12:00
Progress on Proton Charge Radius Measurements 30m

Progress on Proton Charge Radius Measurements

Ashot Gasparian
NC A&T State University

        Abstract


The proton charge radius is one of the fundamental quantities in physics. For the past seventy years it has been measured through elastic electron-proton scattering and ordinary hydrogen spectroscopy methods. Over the years, results from both methods generally agreed with each other within their experimental uncertainties. Unexpectedly, in 2010 (and 2013) two experiments from newly developed muonic hydrogen atomic spectroscopy method reported results up to six standard deviations smaller values than the accepted average from all previous experiments performed on ordinary hydrogen. This discrepancy triggered the well-known proton radius puzzle in hadronic physics. This talk will discuss the post-2010 progress in proton radius measurement methods together with new experimental results and plans for new experiments. In particular, a novel magnetic-spectrometer-free electron-proton scattering experiment (PRad), performed at Jefferson Lab in 2016, will be presented emphasizing its methods and results. Finally, the current status of the proton radius puzzle will be presented and discussed.

Speaker: Prof. Ashot Gasparian (North Carolina A&T State University)
• 12:40 14:10
Plenary Presentations: Plenary 10
• 12:40
Progress on the new solid polarized target by using the symmetry of Perovskite structure 25m

It is widely known that a solid polarized target is a powerful device for researches in spin physics, such as investigation of spin structure of nucleons, nuclear structure, and spin correlation in nuclear reactions. Although about 50 years have already passed since the beginning of studies on the Dynamic Nuclear polarization(DNP), the solid polarized targets are still limited to protons and deuterons in practical beam experiments. A possible method for breaking the above situation is the DNP by using the symmetry of Perovskite structure. This method holds possibilities for realizing the practical polarized targets of nuclei with high quadrupole moments, which are expected as completely new tools for opening up potentialities in Spin Physics. The NOPTREX collaboration applies it to the development of polarized lanthanum(La) targets for discovery of Time-reversal violating effects with ultra-high sensitivity. In this presentation, we will not only introduce the method and its features, but also report current status of development of the polarized La target in the NOPTREX project.

Speaker: Dr Masataka Iinuma (Hiroshima University)
• 13:05
The physics program at EIC: towards the realization 25m

The Electron-Ion Collider (EIC) will be the new, most sophisticated accelerator facility for studying properties of nuclear matter at high intensity and resolving power. Nearly two decades in the planning, the EIC is now the highest priority project for new construction in the US Nuclear Physics Long Range Plan of 2015. It is enthusiastically endorsed by the US National Academy of Sciences in 2018. The EIC will address fundamental open questions on nucleon and nuclear structure, the origin of mass and nucleon spin, and the emergent properties of a dense system of gluons in nuclear matter.

To further sharpen and broaden the physics case and to evaluate experimental requirements for the detector design capable of delivering the EIC physics goal, the EIC Users Group has organized the Yellow Report Initiative. This intensive year-long study of planned physics measurements and required and available detector technologies resulted in the most comprehensive report, providing the basis for further development of experimental setup best suited for science needs.

In this talk, I will summarize the established EIC design capabilities and physics goals and then focus on recent progress in developments of physics measurement, corresponding experimental equipment requirements, and emerging detector concepts on the path for the realization of the EIC.

Speaker: Olga Evdokimov (UIC)