Observation of sizeable ? contribution to?c1(3872) ? p+ p- J=? decays

作者：Aaij, R.; Abdelmotteleb, A. S. W.; Beteta, C. Abellan; Abudinen, F.; Ackernley, T.; Adeva, B.; Adinolfi, M.; Adlarson, P.; Afsharnia, H.; Agapopoulou, C.; Aidala, C. A.; Ajaltouni, Z.; Akar, S.; Akiba, K.; Albrecht, J.; Alessio, F.; Alexander, M.; Alfonso Albero, A.; Aliouche, Z.; Cartelle, P. Alvarez; Amalric, R.; Amato, S.; Amey, J. L.; Amhis, Y.; An, L.; Anderlini, L.; Andersson, M.; Andreianov, A.; Andreotti, M.; Andreou, D.; Ao, D.; Archilli, F.; Artamonov, A.; Artuso, M.; Aslanides, E.

来源：Physical Review D, 2023, 108(1): L011103.

DOI：10.1103/PhysRevD.108.L011103

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Resonant structures in the dipion mass spectrum from & chi;c1(3872) & RARR; & pi;+& pi;-J=& psi; decays, produced via B+ & RARR; K+& chi;c1(3872) decays, are analyzed using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9 fb-1. A sizeable contribution from the isospin conserving & chi;c1(3872) & RARR; & omega;J=& psi; decay is established for the first time, (21.4 & PLUSMN; 2.3 & PLUSMN; 2.0)%, with a significance of more than 7.1 & sigma;. The amplitude of isospin violating decay, & chi;c1(3872) & RARR; & rho;0J=& psi;, relative to isospin conserving decay, & chi;c1(3872) & RARR; & omega;J=& psi;, is properly determined, and it is a factor of 6 larger than expected for a pure charmonium state.