Using pp collision data corresponding to an integrated luminosity of 8.5 fb-1 recorded by the LHCb experiment at center-of-mass energies of s=7, 8, and 13 TeV, the observation of an excited Bc+ state in the Bc+π+π- invariant-mass spectrum is reported. The observed peak has a mass of 6841.2±0.6(stat)±0.1(syst)±0.8(Bc+) MeV/c2, where the last uncertainty is due to the limited knowledge of the Bc+ mass. It is consistent with expectations of the Bc∗(2S31)+ state reconstructed without the low-energy photon from the Bc∗(1S31)+→Bc+γ decay following Bc∗(2S31)+→Bc∗(1S31)+π+π-. A second state is seen with a global (local) statistical significance of 2.2σ (3.2σ) and a mass of 6872.1±1.3(stat)±0.1(syst)±0.8(Bc+) MeV/c2, and is consistent with the Bc(2S10)+ state. These mass measurements are the most precise to date.

Observation of an Excited Bc+ State / Aaij, R., Abellan Beteta, C., Adeva, B., Adinolfi, M., Aidala, C.A., Ajaltouni, Z., Akar, S., Albicocco, P., Albrecht, J., Alessio, F., Alexander, M., Alfonso Albero, A., Alkhazov, G., Alvarez Cartelle, P., Alves, A.A., Amato, S., Amhis, Y., An, L., Anderlini, L., Andreassi, G., et al.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 122:23(2019), p. 232001. [10.1103/PhysRevLett.122.232001]

Observation of an Excited Bc+ State

Capriotti L.;Casse G.;Sarti A.;Sciubba A.;
2019

Abstract

Using pp collision data corresponding to an integrated luminosity of 8.5 fb-1 recorded by the LHCb experiment at center-of-mass energies of s=7, 8, and 13 TeV, the observation of an excited Bc+ state in the Bc+π+π- invariant-mass spectrum is reported. The observed peak has a mass of 6841.2±0.6(stat)±0.1(syst)±0.8(Bc+) MeV/c2, where the last uncertainty is due to the limited knowledge of the Bc+ mass. It is consistent with expectations of the Bc∗(2S31)+ state reconstructed without the low-energy photon from the Bc∗(1S31)+→Bc+γ decay following Bc∗(2S31)+→Bc∗(1S31)+π+π-. A second state is seen with a global (local) statistical significance of 2.2σ (3.2σ) and a mass of 6872.1±1.3(stat)±0.1(syst)±0.8(Bc+) MeV/c2, and is consistent with the Bc(2S10)+ state. These mass measurements are the most precise to date.
2019
Branching fraction, Hadron-Hadron scattering (experiments), QCD
01 Pubblicazione su rivista::01a Articolo in rivista
Observation of an Excited Bc+ State / Aaij, R., Abellan Beteta, C., Adeva, B., Adinolfi, M., Aidala, C.A., Ajaltouni, Z., Akar, S., Albicocco, P., Albrecht, J., Alessio, F., Alexander, M., Alfonso Albero, A., Alkhazov, G., Alvarez Cartelle, P., Alves, A.A., Amato, S., Amhis, Y., An, L., Anderlini, L., Andreassi, G., et al.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 122:23(2019), p. 232001. [10.1103/PhysRevLett.122.232001]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/1310073
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