The first observation of exotic states with a new quark content cc¯us¯ decaying to the J/ψK+ final state is reported with high significance from an amplitude analysis of the B+→J/ψφK+ decay. The analysis is carried out using proton-proton collision data corresponding to a total integrated luminosity of 9 fb-1 collected by the LHCb experiment at center-of-mass energies of 7, 8, and 13 TeV. The most significant state, Zcs(4000)+, has a mass of 4003±6-14+4 MeV, a width of 131±15±26 MeV, and spin parity JP=1+, where the quoted uncertainties are statistical and systematic, respectively. A new 1+ X(4685) state decaying to the J/ψφ final state is also observed with high significance. In addition, the four previously reported J/ψφ states are confirmed and two more exotic states, Zcs(4220)+ and X(4630), are observed with significance exceeding 5 standard deviations.
Aaij, R., Abellan Beteta, C., Ackernley, T., Adeva, B., Adinolfi, M., Afsharnia, H., et al. (2021). Observation of New Resonances Decaying to J /ψK+ and J /ψφ. PHYSICAL REVIEW LETTERS, 127(8) [10.1103/PhysRevLett.127.082001].
Observation of New Resonances Decaying to J /ψK+ and J /ψφ
Borsato M.Membro del Collaboration Group
;Calvi M.Membro del Collaboration Group
;Capelli S.Membro del Collaboration Group
;Carniti P.Membro del Collaboration Group
;Fazzini D.Membro del Collaboration Group
;Garcia Pardinas J.Membro del Collaboration Group
;Gotti C.Membro del Collaboration Group
;Martinazzoli L.Membro del Collaboration Group
;Martinelli M.Membro del Collaboration Group
;Meloni S.Membro del Collaboration Group
;Petruzzo M.Membro del Collaboration Group
;Shields E. B.Membro del Collaboration Group
;
2021
Abstract
The first observation of exotic states with a new quark content cc¯us¯ decaying to the J/ψK+ final state is reported with high significance from an amplitude analysis of the B+→J/ψφK+ decay. The analysis is carried out using proton-proton collision data corresponding to a total integrated luminosity of 9 fb-1 collected by the LHCb experiment at center-of-mass energies of 7, 8, and 13 TeV. The most significant state, Zcs(4000)+, has a mass of 4003±6-14+4 MeV, a width of 131±15±26 MeV, and spin parity JP=1+, where the quoted uncertainties are statistical and systematic, respectively. A new 1+ X(4685) state decaying to the J/ψφ final state is also observed with high significance. In addition, the four previously reported J/ψφ states are confirmed and two more exotic states, Zcs(4220)+ and X(4630), are observed with significance exceeding 5 standard deviations.
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
