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.
Observation of New Resonances Decaying to J /ψK+ and J /ψφ / Aaij, R., Abellan Beteta, C., Ackernley, T., Adeva, B., Adinolfi, M., Afsharnia, H., Aidala, C.A., Aiola, S., Ajaltouni, Z., Akar, S., Albrecht, J., Alessio, F., Alexander, M., Alfonso Albero, A., Aliouche, Z., Alkhazov, G., Alvarez Cartelle, P., Amato, S., Amhis, Y., An, L., et al.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 127:8(2021), pp. 082001-082001. [10.1103/PhysRevLett.127.082001]
Observation of New Resonances Decaying to J /ψK+ and J /ψφ
Bizzeti A.Funding Acquisition
;
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.| File | Dimensione | Formato | |
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PhysRevLett.127.082001.pdf
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