Proton Timelike Form Factors Near Threshold via Antiproton-Nucleus Electromagnetic Annihilation

2010/10/14 by Karmanov, V. A., Fonvieille, H.
#FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #Nuclear Theory (nucl-th)

paper · doi:10.48550/arxiv.1010.2872

Abstract

In the reaction of the antiproton-deuteron electromagnetic annihilation pbar + d --> e+e-n the value of the invariant mass M of the (e+e-) pair can be near or below the (pbar p) mass even for enough high momentum of incident antiproton. This allows to access the proton electromagnetic form factors in the time-like region of q² near the (pbar p) threshold. We estimate the cross section dsigma(pbar + d --> e+e-n)/dM for an antiproton beam momentum of 1.5 GeV/c. We find that near the (pbar p) threshold this cross section is about 1 pb/MeV. The case of heavy nuclei target is also discussed. Elements of experimental feasibility are presented for the process pbar + d --> e+e-n in the context of the Panda project. We conclude that this process has a chance to be measurable at Panda.

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