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...

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...

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.

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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.

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...

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...

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...

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...

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...

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...

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...

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...

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.

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...

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...

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...

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...

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...

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),...

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...

Progress on Proton Charge Radius Measurements

Ashot Gasparian

NC A&T State University

for the PRad Collaboration

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Abstract
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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...

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...

One of the key open questions on the nature of the neutrino is whether it is a Dirac or a Majorana particle. If the neutrino is a Majorana particle, then the interference terms that break the time-reversal symmetry of muon decay appear as the transverse spin polarization of the decay electron [1]. Experiments have been performed at Paul Scherrer Institute to measure the spin polarization of...

In QCD the momentum and spin structure of the nucleon explored in hard-scattering reactions is described in terms of Transverse Momentum Dependent Parton Distribution Functions (TMD PDFs). The PDFs were studied primarily in the collinear approximation, until it was demonstrated that the intrinsic transverse motion of partons plays an important role.

In Semi-Inclusive Deep Inelastic Scattering...

We propose an estimate of cos(2$\phi$) azimuthal asymmetry in $J/\psi$ electroproduction, in an unpolarized electron-proton scattering process. We have used a non-relativistic QCD (NRQCD) framework for the $J/\psi$ production rate. Within the kinematical range of the proposed Electron-Ion Collider (EIC), this can investigate the linearly polarised gluon distribution in the unpolarized proton....

A comprehensive set of azimuthal single-spin and double-spin asymmetries in semi-inclusive leptoproduction of pions, charged kaons, protons, and antiprotons from transversely polarized protons is presented. These asymmetries include the previously published \hermes results on Collins and Sivers asymmetries, the analysis of which has been extended to include protons and antiprotons and also to...

We report preliminary results from the first measurement of a novel beam-spin asymmetry involving the back-to-back production of a target-fragmentation proton and current-fragmentation $\pi^+$. Non-zero $\sin \Delta \phi$ moments for the semi-inclusive deep inelastic scattering process, $ep \rightarrow P \pi^+ X$, where the $\Delta \phi$ is the difference of azimuthal angles between the two...

Spin asymmetries provide a wide range of insights into nucleon structure and

hadronization. Recent measurements of beam spin asymmetries of $\pi^+\pi^-$

dihadrons from SIDIS at CLAS12 provide the first empirical evidence of a nonzero

$G_1^\perp$, the parton helicity-dependent dihadron fragmentation function

(DiFF) encoding spin-momentum correlations in hadronization. These...

The Jülich Electric Dipole moment Investigations (JEDI) collaboration is performing a measurement of the electric dipole moment (EDM) of charged hadrons in storage rings. To perform this measurement with a high precision, it requires a small systematic error. A large contribution to the systematic error is due to unknown magnetic fields, which are picked up when one is off of the optimal...

The beam-spin induced polarization of Λ and anti-Λ hyperons produced in deep-inelastic scattering of longitudinally polarized positrons from unpolarized nucleons has been investigated by the HERMES experiment at a positron beam energy of 27.6 GeV. Here, preliminary results are reported from data taken in the years

1999 to 2007, including in particular the two high-luminosity periods of 2006...

The requirements to hadron polarimetry at future Electron Ion Collider (EIC) include measurements of the absolute helion (${}^3\text{He}$, $h$) beam polarization with systematic uncertainties better than $\sigma^\text{syst}_P/P\le1\%$. Here, we consider a possibility to utilize the Polarized Atomic Hydrogen Gas Jet Target (HJET) for precision measurement of polarization of the...

The $\eta d$ threshold structure $\mathcal{D}_{\eta d}$ with a spin parity of $1^-$ has been experimentally studied in the $\gamma d \to \pi^0 \eta d$ reaction at $E_\gamma \lt 1.15$ GeV. The structure is connected to the isoscalar $S$-wave two-body system between the nucleon $N$ and nucleon resonance $N(1535)1/2^-$, or the chiral partner candidate of $N$. By incorporating the known isovector...

The meson photoproduction is a useful tool to study baryon resonances.Especially, an $\eta$ meson is an isoscalar meson with $s\bar{s}$ components, so it is expected to couple with $\mathrm{N}^{*}$ states with large $s\bar{s}$ components. In previous experiments, the bump structure was seen above 2 GeV in differential cross sections of $\eta$ photoproduction. But in this energy region, many...

Primordial neutrinos decoupled in the early universe predominantly in helicity eigenstates. Their subsequent propagation through the residual cosmic and galactic magnetic fields partially flips their helicities.[1] In view of the possibility of large neutrino magnetic moments arising from beyond-the-standard-model physics -- e.g., as the XENON1T experiment reported as a possible explanation...

In this talk we show how to apply the Soft-Collinear Effective Theory formalism to factorize the Exclusive Double Drell-Yan process, which gives access to Generalized TMDs as well as double TMDs. We discuss the relevance of the soft factor in the factorization theorem and its role in the definition of the GTMDs.

Understanding the internal spin structure of the nucleon still remains a challenge in strong interaction physics. Transversity, which describes the transverse spin structure of quarks in a transversely polarized proton, is still poorly constrained by experimental data. Since it is chiral-odd, it can only be accessed through channels that couple to other chiral-odd distributions, like the...

Data from the Belle Collaboration for associated production (with a light unpolarized hadron) and single-inclusive production of transversely polarized $\Lambda$-hyperons in $e^+e^-$ annihilation processes allowed to extract, for the first time, the $\Lambda$ polarizing fragmentation function, by adopting a simplified TMD approach.

Recent theoretical developments on the computation of cross...

Semi-inclusive deep inelastic scattering (SIDIS) is one of the key processes to extract transverse momentum dependent parton distributions (TMDs). An advantage of electrons is that they are much cleaner probes of nucleon structure than hadron beams, but, at the same time, electron scattering at large momentum transfer can be a source of considerable photon radiation, which can significantly...

In this talk, we report on the first simultaneous extraction of the worm-gear function $g_{1T}$, one of the eight leading-twist TMDs. The study analyzes HERMES, COMPASS and JLab semi-inclusive deep-inelastic scattering data using Monte Carlo techniques. We provide a comparison of $g_{1T}$ obtained from this experimental data with lattice QCD calculations, a large $N_{c}$ analysis, and the...

Electron-positron annihilation into hadrons is one of the fundamental tools for studying non-perturbative QCD effects. Fragmentation functions, describing the formation of hadrons from partons, are an indispensable tool in the interpretation of hadron-production data, e.g., in the investigation of nucleon structure via semi-inclusive deep-inelastic scattering. The cleanest process to access...

We present the complete structure of the azimuthal dependences and polarization observables for two-hadron production in $e^+e^-$ annihilation processes within a TMD approach adopting the helicity formalism. The leading-twist quark and gluon TMD fragmentation functions (FFs) for spin-1/2 hadrons, with their properties and their probabilistic interpretation, are fully accounted for.

The...

The tensor polarization of virtual photons revealed in angular distributions of Drell-Yan processes may be described in simple geometric model.

The results are compared with collier and fixed target data. The model compatibility with pQCD is discussed.

The contribution as a background for TMDs (in particular, Boer-Muders distribution) studies is considered

We perform the first simultaneous QCD global analysis of data from semi-inclusive deep inelastic scattering, Drell-Yan, e+e- annihilation into hadron pairs, and proton-proton collisions. Consequently, we are able to extract a universal set of nonperturbative functions that describes the observed asymmetries in these reactions. The outcome of our analysis indicates single transverse-spin...

We study the polarization of 𝐽/𝜓 mesons produced in semi-inclusive, deep-inelastic electron-proton scattering in different reference frames at the EIC energies. At low transverse momentum, we propose factorized expressions in terms of transverse momentum dependent gluon distributions and shape functions. In particular, we show that the distribution of linearly polarized gluons can, in...

We report on the design and performance of a Mott polarimeter optimized for a nominal 5-MeV electron beam from the Continuous Electron Beam Accelerator Facility (CEBAF) injector. The rf time structure of this beam allows the use of time of flight in the scattered electron detection, making it possible to cleanly isolate those detected electrons that originate from the scattering foil, and...

Our contribution describes design, fabrication and testing of the high voltage system to upgrade the Wien spin rotator to be compatible with the 200 keV electron beam. This required Solidworks modeling, CST and Opera electro- and magnetostatic simulations, upgrading HV vacuum feedthroughs, and assembly techniques for improving electrode alignment. The electric and magnetic fields required by...

Twist-3 distributions are very important quantities for the study of hadron structure, and presently they are poorly known experimentally. In this talk, we present the first-ever results on the proton iso-vector twist-3 PDFs $g_T(x)$ and $h_L(x)$, obtained from lattice QCD. We employ the quasi-PDF approach, which is based on computation of correlation functions between two boosted proton...

In recent years, Laser Plasma Acceleration (LPA) has become a promising alternative to conventional RF accelerators. However, so far, it has only been theoretically shown that polarized LPA beams are possible.

The LEAP (Laser Electron Acceleration with Polarization) project at DESY aims to demonstrate this experimentally for the first time, using a prepolarized plasma target.

The electron...

We make a systemic study on the longitudinal polarization and two transverse polarizations of the $\Lambda$ hyperons produced in unpolarized SIDIS and $e^+e^-$ annihilation.

Recently, Belle collaboration measured the transverse polarization ($P_N$) of $\Lambda$ hyperons in $e^+e^-$ annihilation [1], which inspired three parameterizations of the $D_{1T}^\perp (z,p_T)$ fragmentation function...

A polarized electron beam is being considered as an upgrade for the SuperKEKB accelerator. Having a polarized beam at Belle II opens a new precision electroweak physics program, as well as improving sensitivity to dark sector and lepton flavour violating processes. In order to achieve a polarized beam at SuperKEKB a variety of hardware and technical challenges are being studied. The limiting...

The COMPASS experiment at CERN performed in 2015 and 2018 Drell-Yan measurements using a 190 GeV negative pion beam scattering off a NH3 target and nuclear aluminium and tungsten targets. We will present the differential cross section obtained from that measurement in the kinematic in x-Feynman, transverse momentum, and mass. The results will be valuable input for constraining parton...

Even though Møller scattering has been a subject of several precise experiments, studies of the final spin state in Møller scattering of polarized electron beams offer a unique tool for testing the fundamnetal predictions of relativistic quantum mechanics. The aim of this work was to measure the polarization transfer in Møller scattering (the ratio of the transverse polarization vector...

COMPASS is a fixed-target high energy physics experiment located at the M2 beamline of the Super Proton Synchrotron at CERN. The study of the spin structure of the nucleon by measuring nucleon spin (in)dependent azimuthal asymmetries in Drell-Yan process is one of the main topics of the phase-II research programme of the experiment.

In 2015 and 2018 COMPASS performed Drell-Yan measurements...

We report a new measurement of transverse single-spin asymmetries for pair-production of jets in collisions of transversely polarized protons at $\sqrt{s}$ = 200 GeV with data taken in 2012 and 2015 at STAR. In this measurement we probe, at high $Q^2$, correlations between the transverse spin ($\vec S$) of a proton, moving in the longitudinal ($\vec p$) direction, and the transverse momenta of...

A new particle spin tracking feature has been developed and implemented within General Particle Tracer (GPT). Simulating polarized particles under various conditions within accelerators requires the classical dynamics and time-dependent spin equation of motion. These equations capture the particles behavior as it interacts with electro-magnetic fields. The GPT-Spin extension is able to track...

We perform the first simultaneous global QCD extraction of the transverse momentum dependent (TMD) parton distribution functions and the TMD fragmentation functions in nuclei. We have considered the world set of data from semi-inclusive electron-nucleus deep inelastic scattering and Drell-Yan di-lepton production. In total, this data set consists of 126 data points from HERMES, Fermilab, RHIC...

We will present the current status of nucleon structure studies with physical light quarks ($m_\pi$ = 135 MeV) in two large spatial extents of about 10 and 5 fm. Our calculations are performed on 2+1 flavor gauge configurations generated by PACS collaboration with the stout-smeared $O(a)$ improved Wilson fermions and Iwasaki gauge action at $\beta$=1.82 corresponding to the lattice spacing of...

Muonic helium is a helium atom with one of the two electrons substituted by a negative muon. This three-body atomic system gives rise to opportunities to precisely study the hyperfine structure interval as well as the negative muon magnetic moment and mass. Muonic helium atoms are formed by stopping a negative muon beam in dense helium gas, but in this formation process, the polarization of...

The matter-antimatter asymmetry might be understood by investigating the EDM (Electric Dipole Moment) of elementary particles. A permanent EDM of a subatomic particle violates time reversal and parity symmetry at the same time and a discovery of a non-zero EDM would be a strong indication for physics beyond the Standard Model.

The JEDI-Collaboration (Jülich Electric Dipole moment...

The HERMES experiment has collected a wealth of data using the 27.6 GeV polarized HERA lepton beam and various polarized and unpolarized gaseous targets. This allows for a series of unique measurements of observables sensitive to the multidimensional (spin) structure of the nucleon, in particular semi-inclusive deep-inelastic scattering (SIDIS) measurements, for which the HERMES dual-radiator...

The JEDI (Jülich Electric Dipole moment Investigations) collaboration in Jülich is conducting a set of experiments at the COSY accelerator and storage ring, aiming to develop experimental techniques to measure the EDMs of charged particles, like proton and deuteron. One of the key elements of these experiments is the modular polarimeter (JEPO) with a special target system.

In the current...

Polarization facilities are being developed at the JINR accelerator complex in the framework of the polarization research program under the NICA project. Those are the polarized deuteron and proton source SPI, SPI low energy and linac output polarimeters, and the absolute polarimeter at the NICA collider. The status of the above facilities and the results achieved are presented.

E1039/SpinQuest is a polarized fixed-target Drell-Yan experiment using the 120 GeV proton beam from the Main Injector at Fermilab. The primary goal of SpinQuest is to measure the Sivers asymmetries, aiming to shed light on the fundamental question, “Do the light sea quarks contribute to the intrinsic spin of the nucleon via their orbital angular momentum?”. The Sivers asymmetry was first...

The evolution of primordial neutrino helicities in cosmic magnetic fields and gravitational inhomogeneity has been studied recently [1,2]. Detection of relic neutrinos from the Big Bang, e.g., through the inverse tritium beta decay reaction (ITBD) in the PTOLEMY experiment, remains a major challenge. We examine the implications of the helicity properties of the relic neutrinos on their...

In this talk, I will introduce our recent study on the probing transverse momentum-dependent gluon Sivers function in open heavy flavor quark production at the future EIC. We derive the theoretical framework to calculate heavy-quark pair production in the small transverse momentum region. Based on the factorization and resummation formula, we resum large logarithms in the small qT region and...

We review the recent progress on the extraction of unpolarized TMD PDFs and TMD FFs from global data of Semi-Inclusive Deep-Inelastic Scattering, Drell-Yan and Z boson production. In particular, we address the tension between the low-energy SIDIS data and the theory predictions, and explore the impact of the very precise LHC data on the fit results.

The quasi-PDF approach has made it possible to extract the light-cone PDFs from lattice QCD. In this approach, one calculates matrix elements of space-like operators for boosted hadrons. Quasi-PDFs can be related to the light-cone PDFs through a perturbatively calculable matching coefficient. We address the matching for the very first time for the twist-3 PDFs $g_{T}(x)$ and $h_{L}(x)$. In...

The J-PARC E42 is a dedicated experiment to search for an H-dibaryon near $\Lambda\Lambda$ and $\Xi^{-}p$ threshold. The H-dibaryon is the lightest $S=−2$ system which can be decomposed into a symmetric six-quark object made from $\textit{uuddss}$ quarks and two baryon states involving $\Lambda\Lambda$, $\Xi N$, and $\Sigma\Sigma$ components. E42 detector is highlighted by a large-acceptance...

The recursive quantum mechanical string+3P0 model of polarized quark

fragmentation with pseudoscalar and vector meson production developed recently

has been implemented for the first time in a stand alone Monte Carlo program.

The program allows for a detailed study of the still unknown Collins effect for

vector meson production and of the effects of vector meson decays on the

Collins and...

The matter-antimatter asymmetry may be explained through CP-violation by observing a permanent electric dipole moment (EDM) of subatomic particles. An advanced approach to measure the EDM of charged particles is to apply a unique method of "Frozen spin" on a polarized beam in an accelerator. To increase the experimental precision step by step and to study systematic effects, the EDM experiment...

The SPASCHARM project is aimed at studying a fundamental problem of modern particle physics, such as the mechanism of spin asymmetries in the production of hadrons. The goal of the first stage of the SPASCHARM experiment at the U-70 accelerator in Protvino is the study of single-spin asymmetry in different reactions using negative pion beam with a polarized proton target. SPASCHARM setup was...

We study the Sivers azimuthal asymmetry for $J/\psi$ production in semi-inclusive deeply inelastic scattering, with the aim of gaining information on the poorly known gluon Sivers function. We concentrate on the $J/\psi$ low transverse momentum region, adopting the transverse-momentum dependent generalized parton model (GPM), and its color gauge invariant extension (CGI-GPM), which includes...

The internal structure of jets has been an active research topic in QCD in recent years. In this talk, we propose to use one particular jet substructure - the so-called jet fragmentation function to study spin-dependent distribution and dynamics. In particular, we provide the general theoretical framework for studying the distribution of hadrons inside a jet by taking full advantage of the...

A spin distribution in a high energy $e^{+}$ or $e^{-}$ storage ring is governed by a $(6+1)$ dimensional linear Fokker-Planck-type equation known as the full Bloch equation. Its reduction, the reduced Bloch equation (RBE), is the spin-orbit diffusion equation which takes into account just those terms in the spin-orbit dynamics that suffice for calculating the spin-depolarization rate....

The transverse single-spin asymmetry in inclusive electron-nucleon scattering, e + N(S_T) -> e’ + X, represents a pure two-photon exchange observable and is of fundamental interest for exploring higher-order QED effects in electron scattering. We compute this observable in the resonance region, where excitation of Delta isobars occurs in both intermediate and final states. We employ a novel...

The Spin Transparency technique is discussed as an efficient, highly flexible method for control of the beam polarization. It applies from acceleration to long term maintenance and spin manipulation in real time during an experimental run of a collider or storage ring. This method relies on "transparent" collider structures where, for a particle moving on the design orbit, any initial...

Searches of electric dipole moments (EDM) of charged particles

in pure magnetic rings, such as COSY, or electrostatic and hybrid

magnetic-electric storage rings, planned in the future, require new

methods to disentangle the EDM signal from the large background

produced by magnetic dipole moments. In these experiments, the

sources of systematic background are in-plane magnetic fields. It...

Charmed baryons are actively studied in Belle experiment

and measurements on spin-related phenomena such as

weak decay asymmetries are obtained recently.

In this talk, we will report the determination of

$\Xi_c(2970)$ spin-parity and the measurements of

decay asymmetries in $\Xi_c$ weak decays.

In addition, other results on charmed baryon will be

presented if time allows.

Transverse Momentum Dependent Parton Distribution Functions (TMD PDFs) can be extracted from the processes that are corresponding to multiple kinematic scales such as Drell-Yan (DY), Semi Inclusive Deep Inelastic Scattering (SIDIS) and e+ e− annihilation. Among the eight leading- twist TMD PDFs, there are two time-reversal odd TMDs, namely Sivers function & Boer-Mulders function, which...

I will talk about our recent computation [1] of a gT(x) contribution to transverse single spin asymmetry (SSA) in SIDIS in a collinear framework. In [1] we have found that gT(x) first appears at two-loops. I will explain main steps of our calculation and show the final formula for the cross section [2] in the Wilczek-Wandzura (WW) approximation, that is, neglecting the genuine twist-3 pieces....

The TRIUMF Ultra-Cold Advanced Neutron (TUCAN) collaboration aims at a precision neutron electric dipole moment (nEDM) measurement with an uncertainty of 10$^{-27}$ e$\cdot$cm, which is an order-of-magnitude better than the current nEDM upper limit [1] and enables us to test Supersymmetry. To achieve this precision, our collaboration has been developing a new high-intensity ultracold neutron...

The Lund String Fragmentation Model, widely used in Monte Carlo generators of jets, is extended to include the quark spin as a full quantum-mechanical degree of freedom, described by Pauli spinors. Such a model is needed to describe consistently the azimuthal asymmetries in jets from polarized quarks, like the Collins effect, di-hadron asymmetry and jet handedness.

The model is formulated in...

We re-examine the jet probes of the nucleon spin and flavor structures. We find for the first time

that the time-reversal odd (T-odd) component of a jet, conventionally thought to vanish, can survive

due to the nonperturbative fragmentation and hadronization effects. This additional contribution

of a jet will lead to novel jet phenomena relevant for unlocking the access to several spin...

We use soft collinear effective theory (SCET) to study a dijet production process in deep-inelastic-scattering (DIS), measuring the imbalance of the two hard probes in the Breit frame. In order to achieve factorization of the transverse momentum dependent (TMD) cross-section, we need to introduce a new soft function that we calculate at one-loop, regulating rapidity divergencies with the...

Semi-Inclusive Deep-Inelastic Scattering (SIDIS) is one of the processes that allow us to extract information about Transverse Momentum Distributions (TMDs) and will be the main channel to access TMDs at the future Electron Ion Collider (EIC).

We provide an estimate of the impact that EIC data will have on unpolarized Transverse-Momentum Dependent (TMD) Parton Distribution Functions (PDFs)...

We explain possible transverse-momentum-dependent parton distribution functions (TMDs) for spin-1 hadrons up to twist 4 by decomposing a quark correlation function with the conditions of the Hermiticity and parity invariance [1]. In the TMDs, there exist time-reversal-odd functions in addition to the time-reversal-even ones. We showed that 40 TMDs exist in the tensor-polarized spin-1 hadron in...

We perform explorative analyses of the 3D gluon content of the proton via a study of polarized T-odd gluon TMDs at leading twist, calculated in a spectator model for the parent nucleon. Our approach encodes a flexible parameterization for the spectator-mass density, suited to describe both moderate and small-x effects. All these prospective developments are relevant in the investigation of the...

As part of the investigation programme of the transverse spin and transverse momentum structure of the nucleon in semi-inclusive DIS processes, COMPASS has measured several transverse momentum distributions of the final state hadrons in DIS of 160 GeV/c muons off unpolarised targets.

Recently transverse momentum distributions were obtained by scattering the muons off an isoscalar target...

We study the transverse polarization of hyperons produced

in semi-inclusive deep inelastic scattering, $ep \to e\Lambda^{\uparrow}X$,

in the collinear twist-3 factorization. This process receives three types of

twist-3 contributions: (i) twist-3 distribution in the initial proton combined

with the transversity fragmentation function (FF) for the hyperon,

(ii) Twist-3 quark FFs for the...

Understanding the transverse spin and momentum structure of the proton is of large interest to the nuclear physics community and it is one of the main goals of the spin physics program at the Relativistic Heavy Ion Collider (RHIC). Transverse single spin asymmetry measurements for particles produced in proton-proton collisions provide insight into initial and final state spin-momentum and...

Very forward neutron production cross sections in proton proton collisions are well described by a one pion exchange (OPE) mechanism. However, the simple OPE model alone was not able to explain the large transverse single spin asymmetry ($A_{N}$) that was discovered at RHIC in polarized proton proton collisions. An interference between the spin-flip pion exchange and non-flip $a_1$-Reggeon...

Recently published measurements from the PHENIX experiment at the Relativistic Heavy Ion Collider will be presented for the transverse single-spin asymmetries (TSSAs) of direct photons, neutral pions, and eta mesons produced at midrapidity in 200 GeV proton-proton collisions. As hadrons, neutral pions and eta mesons are sensitive to nonperturbative spin-momentum correlations both within the...

The STAR experiment at RHIC has measured transverse single-spin asymmetries of W±-bosons in proton-proton collisions at a center-of-mass energy √s = 510 GeV (2017 data). These asymmetries probe correlations between parton motion and the proton spin in the initial state which are described in terms of transverse momentum dependent parton distribution functions (TMD), in this case the Sivers...

There have been various attempts, both experimentally and theoretically, to understand the origin of the unexpectedly large transverse single-spin asymmetries ($A_N$) for inclusive hadron production at forward rapidity in p$^\uparrow$+p collisions that persist from low to high center-of-mass energies. Two proposed potential sources are the twist-3 contributions in the collinear factorization...

The study of the partonic and spin structure of the nucleon, using semi-inclusive measurements of hadron muoproduction in Deep Inelastic Scattering (DIS), is one of the main objectives of the COMPASS experiment at CERN. Within the QCD parton model approach, the nucleon structure in DIS can be parametrized in terms of Transverse Momentum Dependent (TMD) Parton Distribution Functions (PDFs),...

At the leading twist, the transversity distribution function, $h^{q}_{1}(x)$, where $x$ is the longitudinal momentum fraction of the proton carried by quark $q$, encodes the transverse spin structure of the proton. Extraction of it is difficult because of its chiral-odd nature. However, it can be coupled to a spin-dependent interference fragmentation function, leading to experimentally...

The transverse spin transfer, $D_{TT}$, of $\Lambda$ and $\overline{\Lambda}$ hyperons in $p$+$p$ collisions is expected to be sensitive to the $s$ and $\bar{s}$ quark transversity distributions in the proton and to the transversely polarized fragmetation functions. The STAR experiment has published the first measurement of the transverse spin transfer of $\Lambda$ and $\overline{\Lambda}$...

We discuss twist-3 gluon fragmentation function (FF) contribution to the polarized hyperon production in unpolarized pp collisions. The final formula for the LO cross section is presented. We emphasize the importance of the Lorentz invariance relations and the QCD equation-of-motion relations among the twist-3 gluon FFs to guarantee the frame independence of the twist-3 cross section. This...