: First evidence of a structure in the J/ψΛ invariant mass distribution is obtained from an amplitude analysis of Ξb-→J/ψΛK- decays. The observed structure is consistent with being due to a charmonium pentaquark with strangeness with a significance of 3.1σ including systematic uncertainties and look-elsewhere effect. Its mass and width are determined to be 4458.8±2.9-1.1+4.7MeV and 17.3±6.5-5.7+8.0MeV, respectively, where the quoted uncertainties are statistical and systematic. The structure is also consistent with being due to two resonances. In addition, the narrow excited Ξ- states, Ξ1690- and Ξ1820-, 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.

Evidence of a J/ψΛ structure and observation of excited Ξ- states in the Ξb-→J/ψΛK- decay / 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: SCIENCE BULLETIN. - ISSN 2095-9281. - 66:13(2021), pp. 1278-1287. [10.1016/j.scib.2021.02.030]

Evidence of a J/ψΛ structure and observation of excited Ξ- states in the Ξb-→J/ψΛK- decay

Casse G.;Sarti A.;Sciubba A.;
2021

Abstract

: First evidence of a structure in the J/ψΛ invariant mass distribution is obtained from an amplitude analysis of Ξb-→J/ψΛK- decays. The observed structure is consistent with being due to a charmonium pentaquark with strangeness with a significance of 3.1σ including systematic uncertainties and look-elsewhere effect. Its mass and width are determined to be 4458.8±2.9-1.1+4.7MeV and 17.3±6.5-5.7+8.0MeV, respectively, where the quoted uncertainties are statistical and systematic. The structure is also consistent with being due to two resonances. In addition, the narrow excited Ξ- states, Ξ1690- and Ξ1820-, 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
Exotics; Particle and resonance production; Pentaquark; QCD; Quarkonium; Spectroscopy
01 Pubblicazione su rivista::01a Articolo in rivista
Evidence of a J/ψΛ structure and observation of excited Ξ- states in the Ξb-→J/ψΛK- decay / 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: SCIENCE BULLETIN. - ISSN 2095-9281. - 66:13(2021), pp. 1278-1287. [10.1016/j.scib.2021.02.030]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/1673463
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