Signals consistent with the B_c^+(2S) and B_c^*+(2S) states are observed in proton-proton collisions at sqrt[s]=13  TeV, in an event sample corresponding to an integrated luminosity of 143  fb^-1, collected by the CMS experiment during the 2015-2018 LHC running periods. These excited b[over ¯]c states are observed in the B_c^+π^+π^- invariant mass spectrum, with the ground state B_c^+ reconstructed through its decay to J/ψπ^+. The two states are reconstructed as two well-resolved peaks, separated in mass by 29.1±1.5(stat)±0.7(syst)  MeV. The observation of two peaks, rather than one, is established with a significance exceeding five standard deviations. The mass of the B_c^+(2S) meson is measured to be 6871.0±1.2(stat)±0.8(syst)±0.8(B_c^+)  MeV, where the last term corresponds to the uncertainty in the world-average B_c^+ mass.

Observation of Two Excited Bc+ States and Measurement of the Bc+ (2S) Mass in pp Collisions at s =13 TeV / Sirunyan, A.M., Tumasyan, A., Adam, W., Ambrogi, F., Bergauer, T., Brandstetter, J., Dragicevic, M., Ero, J., Escalante Del Valle, A., Flechl, M., Fruhwirth, R., Jeitler, M., Krammer, N., Kratschmer, I., Liko, D., Madlener, T., Mikulec, I., Rad, N., Schieck, J., Schofbeck, R., et al.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 122:13(2019), p. 132001. [10.1103/PhysRevLett.122.132001]

Observation of Two Excited Bc+ States and Measurement of the Bc+ (2S) Mass in pp Collisions at s =13 TeV

De Iorio Agostino;Di Crescenzo Antonia;Fienga F.;Iorio A. O. M.;Lista Luca.;
2019

Abstract

Signals consistent with the B_c^+(2S) and B_c^*+(2S) states are observed in proton-proton collisions at sqrt[s]=13  TeV, in an event sample corresponding to an integrated luminosity of 143  fb^-1, collected by the CMS experiment during the 2015-2018 LHC running periods. These excited b[over ¯]c states are observed in the B_c^+π^+π^- invariant mass spectrum, with the ground state B_c^+ reconstructed through its decay to J/ψπ^+. The two states are reconstructed as two well-resolved peaks, separated in mass by 29.1±1.5(stat)±0.7(syst)  MeV. The observation of two peaks, rather than one, is established with a significance exceeding five standard deviations. The mass of the B_c^+(2S) meson is measured to be 6871.0±1.2(stat)±0.8(syst)±0.8(B_c^+)  MeV, where the last term corresponds to the uncertainty in the world-average B_c^+ mass.
2019
Observation of Two Excited Bc+ States and Measurement of the Bc+ (2S) Mass in pp Collisions at s =13 TeV / Sirunyan, A.M., Tumasyan, A., Adam, W., Ambrogi, F., Bergauer, T., Brandstetter, J., Dragicevic, M., Ero, J., Escalante Del Valle, A., Flechl, M., Fruhwirth, R., Jeitler, M., Krammer, N., Kratschmer, I., Liko, D., Madlener, T., Mikulec, I., Rad, N., Schieck, J., Schofbeck, R., et al.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 122:13(2019), p. 132001. [10.1103/PhysRevLett.122.132001]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11588/777233
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