Observation of a Narrow Pentaquark State, P-c(4312)(+), and of the Two-Peak Structure of the P-c(4450)(+)

Aaij, R.; Beteta, C. Abellan; Adeva, B.; Adinolfi, M.; Aidala, C. A.; Ajaltouni, Z.; Akar, S.; Albicocco, P.; Albrecht, J.; Alessio, F.; Alexander, M.; Alfonso Albero, A.; Alkhazov, G.; Cartelle, P. Alvarez; Alves, A. A., Jr.; Amato, S.; Amhis, Y.; An, L.; Anderlini, L.; Andreassi, G.; Andreotti, M.; Andrews, J. E.; Archilli, F.; d'Argent, P.; Romeu, J. Arnau; Artamonov, A.; Artuso, M.; Arzymatov, K.; Aslanides, E.; Atzeni, M.; Audurier, B.; Bachmann, S.; Back, J. J.; Baker, S.; Balagura, V.; Baldini, W.; Baranov, A.; Barlow, R. J.; Barsuk, S.; Barter, W.; Bartolini, M.; Baryshnikov, F.; Batozskaya, V.; Batsukh, B.; Battig, A.; Battista, V.; Bay, A.; Bedeschi, F.; Bediaga, I.; Beiter, A.; Bel, L. J.; Belavin, V.; Belin, S.; Beliy, N.; Bellee, V.; Belloli, N.; Belous, K.; Belyaev, I.; Ben-Haim, E.; Bencivenni, G.; Benson, S.; Beranek, S.; Berezhnoy, A.; Bernet, R.; Berninghoff, D.; Bertholet, E.; Bertolin, A.; Betancourt, C.; Betti, F.; Bettler, M. O.; van Beuzekom, M.; Bezshyiko, Ia.; Bhasin, S.; Bhom, J.; Bieker, M. S.; Bifani, S.; Billoir, P.; Birnkraut, A.; Bizzeti, A.; Bjorn, M.; Blago, M. P.; Blake, T.; Blanc, F.; Blusk, S.; Bobulska, D.; Bocci, V.; Boente Garcia, O.; Boettcher, T.; Bondar, A.; Bondar, N.; Borghi, S.; Borisyak, M.; Borsato, M.; Boubdir, M.; Bowcock, T. J. V.; Bozzi, C.; Braun, S.; Brea Rodriguez, A.; Brodski, M.; Brodzicka, J.; et al.

doi:10.1103/PhysRevLett.122.222001

research article

Observation of a Narrow Pentaquark State, P-c(4312)(+), and of the Two-Peak Structure of the P-c(4450)(+)

Aaij, R.

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Beteta, C. Abellan

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Adeva, B.

June 5, 2019

Physical Review Letters

A narrow pentaquark state, P-c(4312)(+), decaying to J/psi p, is discovered with a statistical significance of 7.3 sigma in a data sample of Lambda(0)(b) -> J/psi pK(-) decays, which is an order of magnitude larger than that previously analyzed by the LHCb Collaboration. The P-c(4450)(+) pentaquark structure formerly reported by LHCb is confirmed and observed to consist of two narrow overlapping peaks, P-c(4440)(+) and P-c(4457)(+), where the statistical significance of this two-peak interpretation is 5.4 sigma. The proximity of the Sigma(+)(c)(D) over bar (0) and Sigma(+)(c)(D) over bar (*0) thresholds to the observed narrow peaks suggests that they play an important role in the dynamics of these states.