A structure is observed in the B±K∓ mass spectrum in a sample of proton–proton collisions at centre-of-mass energies of 7, 8, and 13 TeV, collected with the LHCb detector and corresponding to a total integrated luminosity of 9fb-1. The structure is interpreted as the result of overlapping excited Bs0 states. With high significance, a two-peak hypothesis provides a better description of the data than a single resonance. Under this hypothesis the masses and widths of the two states, assuming they decay directly to B±K∓, are determined to be m1=6063.5±1.2(stat)±0.8(syst)Me,Γ1=26±4(stat)±4(syst)Me,m2=6114±3(stat)±5(syst)Me,Γ2=66±18(stat)±21(syst)Me.Alternative values assuming a decay through B∗ ±K∓, with a missing photon from the B∗ ±→ B±γ decay, which are shifted by approximately 45MeV, are also determined. The possibility of a single state decaying in both channels is also considered. The ratio of the total production cross-section times branching fraction of the new states relative to the previously observed Bs2∗0 state is determined to be 0.87±0.15(stat)±0.19(syst).

Aaij, R., Beteta, C., Ackernley, T., Adeva, B., Adinolfi, M., Afsharnia, H., et al. (2021). Observation of new excited Bs0 states. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS, 81(7) [10.1140/epjc/s10052-021-09305-3].

Observation of new excited Bs0 states

Borsato M.;Calvi M.;Capelli S.;Carniti P.;Fazzini D.;Garcia Pardinas J.;Gotti C.;Martinazzoli L.;Martinelli M.;Meloni S.;Petruzzo M.;Shields E. B.;
2021

Abstract

A structure is observed in the B±K∓ mass spectrum in a sample of proton–proton collisions at centre-of-mass energies of 7, 8, and 13 TeV, collected with the LHCb detector and corresponding to a total integrated luminosity of 9fb-1. The structure is interpreted as the result of overlapping excited Bs0 states. With high significance, a two-peak hypothesis provides a better description of the data than a single resonance. Under this hypothesis the masses and widths of the two states, assuming they decay directly to B±K∓, are determined to be m1=6063.5±1.2(stat)±0.8(syst)Me,Γ1=26±4(stat)±4(syst)Me,m2=6114±3(stat)±5(syst)Me,Γ2=66±18(stat)±21(syst)Me.Alternative values assuming a decay through B∗ ±K∓, with a missing photon from the B∗ ±→ B±γ decay, which are shifted by approximately 45MeV, are also determined. The possibility of a single state decaying in both channels is also considered. The ratio of the total production cross-section times branching fraction of the new states relative to the previously observed Bs2∗0 state is determined to be 0.87±0.15(stat)±0.19(syst).
Articolo in rivista - Articolo scientifico
Heavy Quarks Spectroscopy; Particles and Fields
English
12-lug-2021
2021
81
7
601
none
Aaij, R., Beteta, C., Ackernley, T., Adeva, B., Adinolfi, M., Afsharnia, H., et al. (2021). Observation of new excited Bs0 states. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS, 81(7) [10.1140/epjc/s10052-021-09305-3].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/338370
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