, 48:33,
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Date: 20 Mar 2012

No Sommerfeld resummation factor in \(e^ + e^ - \to p\bar p\) ?


The Sommerfeld rescattering formula is compared to the \(e^ + e^ - \to p\bar p\) BABAR data at threshold and above. While there is the expected Coulomb enhancement at threshold, two unexpected outcomes have been found: the modulus of the proton form factor is normalized to one at threshold, i.e. |G p (4M p 2 )| = 1, as a pointlike fermion, and, moreover, data show that the resummation factor in the Sommerfeld formula is not needed. Other e + e → baryon-antibaryon cross-sections show similar behavior near threshold.

This article is published with open access at Springerlink.com
Communicated by J. Bijnens