%0 Journal Article
%T Measurement of initial-state-final-state radiation interference in the processes e(+)e(-) -> mu(+)mu(-)gamma and e(+)e(-) -> pi(+)pi(-)gamma
%A BABAR Collaboration (Lees, J. P. et al
%A Martinez-Vidal, F.
%A Oyanguren, A.
%J Physical Review D
%D 2015
%V 92
%N 7
%I Amer Physical Soc
%@ 1550-7998
%G English
%F BABARCollaborationLees_etal2015
%O WOS:000363527500001
%O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=2433), last updated on Thu, 19 Nov 2015 12:54:50 +0000
%X Charge asymmetry in the processes e(+)e(-) -> mu(+)mu(-)gamma and e(+)e(-) -> pi(+)pi(-)gamma is measured using 232 fb(-1) of data collected with the BABAR detector at e(+)e(-) center-of-mass energies near 10.58 GeV. An observable is introduced and shown to be very robust against detector asymmetries while keeping a large sensitivity to the physical charge asymmetry that results from the interference between initial-and final-state radiation (FSR). The asymmetry is determined as a function of the invariant mass of the final-state tracks from production threshold to a few GeV/c(2). It is compared to the expectation from QED for e(+)e(-) -> mu(+)mu(-)gamma, and from theoretical models for e(+)e(-) -> pi(+)pi(-)gamma. A clear interference pattern is observed in e(+)e(-) -> pi(+)pi(-)gamma, particularly in the vicinity of the f(2)(1270) resonance. The inferred rate of lowest-order FSR production is consistent with the QED expectation for e(+)e(-) -> mu(+)mu(-)gamma, and is negligibly small for e(+)e(-) -> pi(+)pi(-)gamma.
%R 10.1103/PhysRevD.92.072015
%U http://arxiv.org/abs/1508.04008
%U https://doi.org/10.1103/PhysRevD.92.072015
%P 072015-29pp