Extraction of the proton mass radius from the vector meson photoproductions near thresholds
| Autor: | Wei Kou, Ya-Ping Xie, Rong Wang, Xurong Chen |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Quantum chromodynamics
Physics Particle physics Meson Proton 010308 nuclear & particles physics Scalar (mathematics) Nuclear Theory Form factor (quantum field theory) FOS: Physical sciences Quarkonium 01 natural sciences Omega High Energy Physics - Phenomenology High Energy Physics - Phenomenology (hep-ph) 0103 physical sciences High Energy Physics::Experiment Vector meson Astrophysics::Earth and Planetary Astrophysics 010306 general physics Nuclear Experiment |
| Zdroj: | Physical Review |
| Popis: | We present an analysis of the proton mass radius by studying the $t$-dependence of the differential cross sections of the vector meson photoproductions near the thresholds. At low energy, the photoproduction of a quarkonium off the proton is connected to the scalar gravitational form factor of the proton, which is sensitive to the proton mass distribution from the QCD trace anomaly. Under an assumption of the scalar form factor of dipole form, the proton mass radius is extracted via the near-threshold photoproduction data of J/$\psi$, $\phi$ and $\omega$ vector mesons. The average value of the proton mass radius is estimated to be $\sqrt{\left} = 0.67\pm0.03$ fm, with the dipole cutoff $m_{\rm s}=1.01\pm0.04$ GeV. Comment: 5 pages, 2 figures, minor modifications |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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