Relativization of the Sommerfeld-Gamow-Sakharov factor

Abstract

Abstract:The Sommerfeld-Gamow-Sakharov factor is considered for the general case of arbitrary masses and energies. It is shown that the scalar triangular one-loop diagram gives the Coulomb singularity in radiative corrections at the threshold. The singular part of the correction is factorized at the complete Born cross section regardless of its partial wave decomposition. Different approaches to generalize the factor are discussed.

Study ofe+e−→pp¯via initial-state radiation atBABAR

“…(3). The definition of the form factor permits comparison of our measurement with measurements from other experiments, most of which were made under the assumption |G E | = |G M |.…”

“…[3] and references therein), which results in a non-zero cross section at threshold, and G M and G E are the magnetic and electric form factors, respectively (|G E | = |G M | at threshold). From measurement of the cross section, a linear combination of the squared form factors can be determined.…”

Study of the processe+e−→nn¯Ачасов1, Barnyakov2, Beloborodov3 et al. 2014Phys. Rev. D831561View full textAdd to dashboardCite

“…where s = 4E 2 b , E b is the beam energy, β = 1 − 4m 2 B /s, C is a factor taking into account Coulomb interaction of the final baryons [C = y/(1 − e −y ) with y = πα(1 + β 2 )/β for protons [1], and C = 1 for neutrons], τ = s/4m 2 B , and θ is the baryon polar angle in the e + e − center-of-mass (c.m.) frame.…”

The time-like electromagnetic form factors of proton and charged kaon at high energies

“…The Coulomb interaction factor C accounts for the electromagnetic pp final state interactions (see [1] and references therein).…”