학술논문
Measurement of initial-state-final-state radiation interference in the processes e+e- →μ+μ-γ and e+e- →π+π-γ
Document Type
article
Author
Lees, JP; Poireau, V; Tisserand, V; Grauges, E; Palano, A; Eigen, G; Stugu, B; Brown, DN; Kerth, LT; Kolomensky, YG; Lee, MJ; Lynch, G; Koch, H; Schroeder, T; Hearty, C; Mattison, TS; McKenna, JA; So, RY; Khan, A; Blinov, VE; Buzykaev, AR; Druzhinin, VP; Golubev, VB; Kravchenko, EA; Onuchin, AP; Serednyakov, SI; Skovpen, YI; Solodov, EP; Todyshev, KY; Lankford, AJ; Dey, B; Gary, JW; Long, O; Franco Sevilla, M; Hong, TM; Kovalskyi, D; Richman, JD; West, CA; Eisner, AM; Lockman, WS; Panduro Vazquez, W; Schumm, BA; Seiden, A; Chao, DS; Cheng, CH; Echenard, B; Flood, KT; Hitlin, DG; Kim, J; Miyashita, TS; Ongmongkolkul, P; Porter, FC; Röhrken, M; Andreassen, R; Huard, Z; Meadows, BT; Pushpawela, BG; Sokoloff, MD; Sun, L; Ford, WT; Smith, JG; Wagner, SR; Ayad, R; Toki, WH; Spaan, B; Bernard, D; Verderi, M; Playfer, S; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Fioravanti, E; Garzia, I; Luppi, E; Piemontese, L; Santoro, V; Calcaterra, A; De Sangro, R; Finocchiaro, G; Martellotti, S; Patteri, P; Peruzzi, IM; Piccolo, M; Zallo, A; Contri, R; Monge, MR; Passaggio, S; Patrignani, C; Bhuyan, B; Prasad, V; Adametz, A; Uwer, U; Lacker, HM; Mallik, U; Chen, C; Cochran, J; Prell, S; Ahmed, H; Gritsan, AV
Source
Physical Review D - Particles, Fields, Gravitation and Cosmology. 92(7)
Subject
Language
Abstract
Charge asymmetry in the processes e+e-→μ+μ-γ and e+e-→π+π-γ 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/c2. It is compared to the expectation from QED for e+e-→μ+μ-γ, and from theoretical models for e+e-→π+π-γ. A clear interference pattern is observed in e+e-→π+π-γ, particularly in the vicinity of the f2(1270) resonance. The inferred rate of lowest-order FSR production is consistent with the QED expectation for e+e-→μ+μ-γ, and is negligibly small for e+e-→π+π-γ.