Conveners
Form Factors and GPDs: Chair: Wen-Chen Chang
- Itaru Nakagawa (RIKEN)
- Wen-Chen Chang (Institute of Physics, Academia Sinica)
- Marie Boer
Form Factors and GPDs: Chair: Wen-Chen Chang, Itaru Nakagawa
- Marie Boer
- Wen-Chen Chang (Institute of Physics, Academia Sinica)
- Itaru Nakagawa (RIKEN)
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...
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...
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 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...
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 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...
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...
