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. © 2021 CERN.

Observation of New Resonances Decaying to J /ψK+ and J /ψφ

De Serio, M.;Pappagallo, M.;Simone, S.;
2021-01-01

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. © 2021 CERN.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11586/379191
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 116
  • ???jsp.display-item.citation.isi??? 99
social impact