First evidence of a structure in the J/ψ Λ invariant mass distribution is obtained from an amplitude analysis of Ξb− → J/ψ Λ K− decays. The observed structure is consistent with being due to a charmonium pentaquark with strangeness. Its mass and width are determined to be 4458.8 ± 2.9{−1.1}{+4.7} MeV and 17.3 ± 6.5{−5.7}{+8.0} MeV, where the quoted uncertainties are statistical and systematic, respectively. The structure is also consistent with being due to two resonances. In addition, the narrow excited Ξ− states, Ξ(1690)− and Ξ(1820)−, are seen for the first time in a Ξb− decay, and their masses and widths are measured with improved precision. The analysis is performed using pp collision data corresponding to a total integrated luminosity of 9 fb^−1, collected with the LHCb experiment at centre-of-mass energies of 7, 8 and 13 TeV.

Aaij, R., Abellán Beteta, C., Ackernley, T., Adeva, B., Adinolfi, M., Afsharnia, H., et al. (2021). Evidence of a J/ψ Λ Structure and Observation of Excited Ξ− States in the Ξb− → J/ψ Λ K− Decay. SCIENCE BULLETIN, 66(13), 1278-1287 [10.1016/j.scib.2021.02.030].

Evidence of a J/ψ Λ Structure and Observation of Excited Ξ− States in the Ξb− → J/ψ Λ K− Decay

Capriotti, L.;Carbone, A.;Ferrari, F.;Galli, D.;Maccolini, S.;Manuzzi, D.;Patrignani, C.;Pisani, F.;Zucchelli, S.;
2021

Abstract

First evidence of a structure in the J/ψ Λ invariant mass distribution is obtained from an amplitude analysis of Ξb− → J/ψ Λ K− decays. The observed structure is consistent with being due to a charmonium pentaquark with strangeness. Its mass and width are determined to be 4458.8 ± 2.9{−1.1}{+4.7} MeV and 17.3 ± 6.5{−5.7}{+8.0} MeV, where the quoted uncertainties are statistical and systematic, respectively. The structure is also consistent with being due to two resonances. In addition, the narrow excited Ξ− states, Ξ(1690)− and Ξ(1820)−, are seen for the first time in a Ξb− decay, and their masses and widths are measured with improved precision. The analysis is performed using pp collision data corresponding to a total integrated luminosity of 9 fb^−1, collected with the LHCb experiment at centre-of-mass energies of 7, 8 and 13 TeV.
2021
Aaij, R., Abellán Beteta, C., Ackernley, T., Adeva, B., Adinolfi, M., Afsharnia, H., et al. (2021). Evidence of a J/ψ Λ Structure and Observation of Excited Ξ− States in the Ξb− → J/ψ Λ K− Decay. SCIENCE BULLETIN, 66(13), 1278-1287 [10.1016/j.scib.2021.02.030].
Aaij, R.; Abellán Beteta, C.; Ackernley, T.; Adeva, B.; Adinolfi, M.; Afsharnia, H.; Aidala, C.A.; Aiola, S.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; A...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/849049
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