Observation of a new charged charmoniumlike state in B -> J/psi K pi decays
hep-ex
/ Authors
Belle Collaboration, K. Chilikin, R. Mizuk, I. Adachi, H. Aihara, S. Al Said, K. Arinstein, D. M. Asner, V. Aulchenko, T. Aushev
and 155 more authors
R. Ayad, T. Aziz, A. M. Bakich, V. Bansal, A. Bondar, G. Bonvicini, A. Bozek, M. Bračko, T. E. Browder, D. Červenkov, V. Chekelian, A. Chen, B. G. Cheon, R. Chistov, K. Cho, V. Chobanova, S. -K. Choi, Y. Choi, D. Cinabro, M. Danilov, Z. Doležal, Z. Drásal, A. Drutskoy, K. Dutta
/ Abstract
We present the results of an amplitude analysis of anti-B0 -> J/psi K- pi+ decays. A new charged charmoniumlike state Zc(4200)+ decaying to J/psi pi+ is observed with a significance of 6.2 sigma. The mass and width of the Zc(4200)+ are 4196 +31-29 +17-13 MeV/c^2 and 370 +70-70 +70-132 MeV, respectively; the preferred assignment of the quantum numbers is J^P = 1^+. In addition, we find evidence for Zc(4430)+ -> J/psi pi+. The analysis is based on a 711 fb^-1 data sample collected by the Belle detector at the asymmetric-energy e+ e- collider KEKB.