Observations of exotic structures in the J/ψp channel, which we refer to as charmonium-pentaquark states, in Λb0→J/ψK-p decays are presented. The data sample corresponds to an integrated luminosity of 3fb-1 acquired with the LHCb detector from 7 and 8 TeV pp collisions. An amplitude analysis of the three-body final state reproduces the two-body mass and angular distributions. To obtain a satisfactory fit of the structures seen in the J/ψp mass spectrum, it is necessary to include two Breit-Wigner amplitudes that each describe a resonant state. The significance of each of these resonances is more than 9 standard deviations. One has a mass of 4380±8±29MeV and a width of 205±18±86MeV, while the second is narrower, with a mass of 4449.8±1.7±2.5MeV and a width of 39±5±19MeV. The preferred JP assignments are of opposite parity, with one state having spin 3/2 and the other 5/2.

Aaij, R., Adeva, B., Adinolfi, M., Affolder, A., Ajaltouni, Z., Akar, S., et al. (2015). Observation of J /ψp Resonances Consistent with Pentaquark States in Λb0 →j /ψK-p Decays. PHYSICAL REVIEW LETTERS, 115(7) [10.1103/PhysRevLett.115.072001].

Observation of J /ψp Resonances Consistent with Pentaquark States in Λb0 →j /ψK-p Decays

BELLOLI, NICOLETTA;Borsato, M;CALVI, MARTA;CARNITI, PAOLO;CASSINA, LORENZO;GOTTI, CLAUDIO;KHANJI, BASEM;Martinelli, M;Petruzzo, M;
2015

Abstract

Observations of exotic structures in the J/ψp channel, which we refer to as charmonium-pentaquark states, in Λb0→J/ψK-p decays are presented. The data sample corresponds to an integrated luminosity of 3fb-1 acquired with the LHCb detector from 7 and 8 TeV pp collisions. An amplitude analysis of the three-body final state reproduces the two-body mass and angular distributions. To obtain a satisfactory fit of the structures seen in the J/ψp mass spectrum, it is necessary to include two Breit-Wigner amplitudes that each describe a resonant state. The significance of each of these resonances is more than 9 standard deviations. One has a mass of 4380±8±29MeV and a width of 205±18±86MeV, while the second is narrower, with a mass of 4449.8±1.7±2.5MeV and a width of 39±5±19MeV. The preferred JP assignments are of opposite parity, with one state having spin 3/2 and the other 5/2.
Articolo in rivista - Articolo scientifico
Mass spectrometry; Tellurium compounds Amplitude analysis; Data sample; Exotic structures; Integrated luminosity; Mass spectra; Pentaquark state; Resonant state; Standard deviation
English
2015
115
7
072001
reserved
Aaij, R., Adeva, B., Adinolfi, M., Affolder, A., Ajaltouni, Z., Akar, S., et al. (2015). Observation of J /ψp Resonances Consistent with Pentaquark States in Λb0 →j /ψK-p Decays. PHYSICAL REVIEW LETTERS, 115(7) [10.1103/PhysRevLett.115.072001].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/90832
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