TY  - JOUR
AU  - BABAR Collaboration (Lees, J. P. et al
AU  - Martinez-Vidal, F.
AU  - Oyanguren, A.
PY  - 2015
DA  - 2015//
TI  - Measurement of initial-state-final-state radiation interference in the processes e(+)e(-) -> mu(+)mu(-)gamma and e(+)e(-) -> pi(+)pi(-)gamma
T2  - Phys. Rev. D
JO  - Physical Review D
SP  - 072015
EP  - 29pp
VL  - 92
IS  - 7
PB  - Amer Physical Soc
AB  - 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.
SN  - 1550-7998
UR  - http://arxiv.org/abs/1508.04008
UR  - https://doi.org/10.1103/PhysRevD.92.072015
DO  - 10.1103/PhysRevD.92.072015
LA  - English
N1  - WOS:000363527500001
ID  - BABARCollaborationLees_etal2015
ER  -