Back to Search
Start Over
Extraction of beam-spin asymmetries from the hard exclusive π+ channel off protons in a wide range of kinematics
- Source :
- Phys.Rev.Lett., Phys.Rev.Lett., 2020, 125 (18), pp.182001. ⟨10.1103/PhysRevLett.125.182001⟩
- Publication Year :
- 2020
- Publisher :
- American Physical Society, 2020.
-
Abstract
- We have measured beam-spin asymmetries to extract the \ud sin\ud ϕ\ud moment \ud A\ud sin\ud ϕ\ud L\ud U\ud from the hard exclusive \ud →\ud e\ud p\ud →\ud e\ud ′\ud n\ud π\ud +\ud reaction above the resonance region, for the first time with nearly full coverage from forward to backward angles in the center of mass. The \ud A\ud sin\ud ϕ\ud L\ud U\ud moment has been measured up to \ud 6.6\ud \ud \ud GeV\ud 2\ud in \ud −\ud t\ud , covering the kinematic regimes of generalized parton distributions (GPD) and baryon-to-meson transition distribution amplitudes (TDA) at the same time. The experimental results in very forward kinematics demonstrate the sensitivity to chiral-odd and chiral-even GPDs. In very backward kinematics where the TDA framework is applicable, we found \ud A\ud sin\ud ϕ\ud L\ud U\ud to be negative, while a sign change was observed near 90° in the center of mass. The unique results presented in this Letter will provide critical constraints to establish reaction mechanisms that can help to further develop the GPD and TDA frameworks.
- Subjects :
- Particle physics
generalized parton distribution
Partons
Nucleons
Compton Scattering
media_common.quotation_subject
General Physics and Astronomy
parton: distribution function
Socio-culturale
Parton
[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex]
01 natural sciences
Resonance (particle physics)
Asymmetry
High Energy Physics - Experiment
Pion
PE2_2
PE2_1
CLAS
0103 physical sciences
[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]
010306 general physics
Nuclear Experiment
PE2_3
Spin-½
media_common
Physics
Settore FIS/04
electroproduction
moment
Moment (mathematics)
distribution amplitude
High Energy Physics - Phenomenology
Amplitude
kinematics
[PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph]
Elementary Particles and Fields
High Energy Physics::Experiment
Center of mass
asymmetry
experimental results
Subjects
Details
- Language :
- English
- ISSN :
- 00319007
- Database :
- OpenAIRE
- Journal :
- Phys.Rev.Lett., Phys.Rev.Lett., 2020, 125 (18), pp.182001. ⟨10.1103/PhysRevLett.125.182001⟩
- Accession number :
- edsair.doi.dedup.....ad51c5afe8be18c8c69b21550f47db95