0000000000783805

AUTHOR

Chaden Djalali

showing 2 related works from this author

Beam-Helicity Asymmetries in Double-Charged-Pion Photoproduction on the Proton

2005

Beam-helicity asymmetries for the two-pion-photoproduction reaction gamma + p --> p pi+ pi- have been studied for the first time in the resonance region for center-of-mass energies between 1.35 GeV and 2.30 GeV. The experiment was performed at Jefferson Lab with the CEBAF Large Acceptance Spectrometer using circularly polarized tagged photons incident on an unpolarized hydrogen target. Beam-helicity-dependent angular distributions of the final-state particles were measured. The large cross-section asymmetries exhibit strong sensitivity to the kinematics and dynamics of the reaction. The data are compared with the results of various phenomenological model calculations, and show that these…

Particle physicsPhotonProtonGeneral Physics and AstronomyFOS: Physical sciences13.60.-r 13.60.Le 13.88.+e[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex]01 natural sciencesHigh Energy Physics - ExperimentNuclear physicsHigh Energy Physics - Experiment (hep-ex)Pion0103 physical sciencesPhenomenological model[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]Nuclear Experiment (nucl-ex)010306 general physicsNuclear ExperimentNuclear ExperimentPhysics010308 nuclear & particles physicsBremsstrahlungHelicity3. Good healthPair productionNucleon
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ProjectileΔand target Roper excitation in thep(d,d′)Xreaction

2000

In this paper we compare a model that contains the mechanisms of $\ensuremath{\Delta}$ excitation in the projectile and Roper excitation in the target with experimental data from two ${(d,d}^{\ensuremath{'}})$ experiments on a proton target. The agreement of the theory with the experiment is fair for the data taken at ${T}_{d}=2.3$ GeV. The $\ensuremath{\Delta}$ excitation in the projectile is predicted close to the observed energy with the correct width. The theory, however, underpredicts by about 40% the cross sections measured at ${T}_{d} = 1.6$ GeV at angles where the cross section has fallen by about two orders of magnitude. The analysis done here allows us to extract an approximate st…

PhysicsNuclear and High Energy PhysicsProton010308 nuclear & particles physicsProjectile01 natural sciencesNuclear physicsCross section (physics)0103 physical sciencesAtomic physicsNuclear Experiment010306 general physicsNuclear theoryExcitationEnergy (signal processing)Order of magnitudePhysical Review C
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