Journal Article

Measurement of the phase difference between short- and long-distance amplitudes in the Formula: see text decay

Girard, O G, Costa Sobral, C M, Brodzicka, J, Koopman, R F, Esen, S, Ferguson, D, Fiore, M, Jalocha, J, Tully, A, Shevchenko, V, shaw, D C, Koliiev, S, Artuso, M, Meissner, M, Tonelli, D, Xing, Z, Lucchesi, D, Hennessy, K, Mathad, A, Batsukh, B, Charles, M, Gys, T, Raven, G, Vecchi, S, Voneki, B, Yushchenko, O, Dzyuba, A, Borgheresi, A, Pappalardo, L L, Gazzoni, G, Jurik, N, Gao, Y, Kuonen, A K, Jans, E, Lionetto, F, Saunders, D M, Xu, Z, Buchanan, E, Viemann, H, Bowen, E, Nikitin, N, Kucharczyk, M, Maurice, E, Nasteva, I, Gushchin, E, Monteil, S, Silva de Oliveira, L, Petridis, K, Dujany, G, De Miranda, J M, Kariuki, J M, Cavallero, G, Tisserand, V, Liu, X, Zarebski, K A, Borsato, M, Mulder, M, Hicheur, A, Fini, R A, Likhomanenko, T, Wislicki, W, Punzi, G, Beddow, J, Benson, S, Ronayne, J W, Evans, T, Perret, P, Blanc, F, Grillo, L, Kandybei, S, Santovetti, E, Couturier, B, Easo, S, Needham, M, Wishahi, J, Carboni, G, Chamont, D, Matev, R, Bezshyiko, Ia, Giubega, L, Santamarina Rios, C, Patrignani, C, Campana, P, Prouve, C, Wotton, S A, Ely, S, Hopchev, H, Cheung, S-F, Zhang, Y, Harnew, S T, Lai, A, Schubert, K, Baalouch, M, Blouw, J, Manca, G, Klimaszewski, K, van Veghel,

2017

Overview

A measurement of the phase difference between the short- and long-distance contributions to the [Formula: see text] decay is performed by analysing the dimuon mass distribution. The analysis is based on pp collision data corresponding to an integrated luminosity of 3[Formula: see text] collected by the LHCb experiment in 2011 and 2012. The long-distance contribution to the [Formula: see text] decay is modelled as a sum of relativistic Breit-Wigner amplitudes representing different vector meson resonances decaying to muon pairs, each with their own magnitude and phase. The measured phases of the [Formula: see text] and [Formula: see text] resonances are such that the interference with the short-distance component in dimuon mass regions far from their pole masses is small. In addition, constraints are placed on the Wilson coefficients, [Formula: see text] and [Formula: see text], and the branching fraction of the short-distance component is measured.A measurement of the phase difference between the short- and long-distance contributions to the [Formula: see text] decay is performed by analysing the dimuon mass distribution. The analysis is based on pp collision data corresponding to an integrated luminosity of 3[Formula: see text] collected by the LHCb experiment in 2011 and 2012. The long-distance contribution to the [Formula: see text] decay is modelled as a sum of relativistic Breit-Wigner amplitudes representing different vector meson resonances decaying to muon pairs, each with their own magnitude and phase. The measured phases of the [Formula: see text] and [Formula: see text] resonances are such that the interference with the short-distance component in dimuon mass regions far from their pole masses is small. In addition, constraints are placed on the Wilson coefficients, [Formula: see text] and [Formula: see text], and the branching fraction of the short-distance component is measured.