Observations of exotic structures in the J=ψp channel, which we refer to as charmonium-pentaquark states, in Λ0 b → J=ψK−p decays are presented. The data sample corresponds to an integrated luminosity of 3 fb−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 29 MeV and a width of 205 18 86 MeV, while the second is narrower, with a mass of 4449.8 1.7 2.5 MeV and a width of 39 5 19 MeV. The preferred JP assignments are of opposite parity, with one state having spin 3=2 and the other 5=2.

Observation of J /ψp Resonances Consistent with Pentaquark States in Λb0 →j /ψK-p Decays / Aaij, R., Adeva, B., Adinolfi, M., Affolder, A., Ajaltouni, Z., Akar, S., Albrecht, J., Alessio, F., Alexander, M., Ali, S., Alkhazov, G., Alvarez Cartelle, P., Alves, A.A., Amato, S., Amerio, S., Amhis, Y., An, L., Anderlini, L., Anderson, J., Andreassi, G., et al.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 115:7(2015), p. 072001. [10.1103/PhysRevLett.115.072001]

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

Capriotti, L.;Casse, G.;SARTI, ALESSIO;SCIUBBA, Adalberto;
2015

Abstract

Observations of exotic structures in the J=ψp channel, which we refer to as charmonium-pentaquark states, in Λ0 b → J=ψK−p decays are presented. The data sample corresponds to an integrated luminosity of 3 fb−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 29 MeV and a width of 205 18 86 MeV, while the second is narrower, with a mass of 4449.8 1.7 2.5 MeV and a width of 39 5 19 MeV. The preferred JP assignments are of opposite parity, with one state having spin 3=2 and the other 5=2.
2015
Heavy quarkonia, Decays of J/ψ, Υ, and other quarkonia
01 Pubblicazione su rivista::01a Articolo in rivista
Observation of J /ψp Resonances Consistent with Pentaquark States in Λb0 →j /ψK-p Decays / Aaij, R., Adeva, B., Adinolfi, M., Affolder, A., Ajaltouni, Z., Akar, S., Albrecht, J., Alessio, F., Alexander, M., Ali, S., Alkhazov, G., Alvarez Cartelle, P., Alves, A.A., Amato, S., Amerio, S., Amhis, Y., An, L., Anderlini, L., Anderson, J., Andreassi, G., et al.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 115:7(2015), p. 072001. [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/11573/836100
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