论文信息 - Observation of J/p resonances consistent with pentaquark states in [0 over b] J/K[superscript -]p decays

Observation of J/p resonances consistent with pentaquark states in [0 over b] J/K[superscript -]p decays

Observations of exotic structures in the J= ψ p channel, which we refer to as charmonium-pentaquark states, in Λ 0 b → J= ψ K − 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= ψ p 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 (cid:1) 8 (cid:1) 29 MeV and a width of 205 (cid:1) 18 (cid:1) 86 MeV, while the second is narrower, with a mass of 4449 . 8 (cid:1) 1 . 7 (cid:1) 2 . 5 MeV and a width of 39 (cid:1) 5 (cid:1) 19 MeV. The preferred J P assignments are of opposite parity, with one state having spin 3 = 2 and the other 5 = 2 .

[1] S. L. Olsen. Multiquark Hadrons , 2016, 1611.01277.

[2] E. Swanson. Z b and Z c exotic states as coupled channel cusps , 2014, 1409.3291.

[3] Xiang Liu,et al. A possible global group structure for exotic states , 2014, 1409.3332.

[4] C Bozzi,et al. Observation of overlapping spin-1 and spin-3 D0K- resonances at mass 2.86 GeV/c2. , 2014, Physical review letters.

[5] D. M. Santos,et al. Mass distributions marginalized over per-event errors , 2013, 1312.5000.

[6] J. Michałowski,et al. Performance of the LHCb Outer Tracker , 2013, 1311.3893.

[7] S. Malde,et al. Performance of the LHCb RICH detector at the LHC , 2012, The European physical journal. C, Particles and fields.

[8] G. Manca,et al. Performance of the LHCb muon system , 2012, 1211.1346.

[9] A. Bhattacharya,et al. Heavy pentaquarks and doubly heavy baryons in quasiparticle approach , 2012 .

[10] K. Hicks. On the conundrum of the pentaquark , 2012 .

[11] S. Miglioranzi,et al. The LHCb Simulation Application, Gauss: Design, Evolution and Experience , 2011 .

[12] T. Shears,et al. Performance of the LHCb Vertex Locator , 2011, 2012 IEEE Nuclear Science Symposium and Medical Imaging Conference Record (NSS/MIC).

[13] P. Harrison,et al. Handling of the generation of primary events in Gauss, the LHCb simulation framework , 2010, IEEE Nuclear Science Symposuim & Medical Imaging Conference.

[14] R. Molina,et al. Prediction of narrow N* and Λ* resonances with hidden charm above 4 GeV. , 2010, Physical review letters.

[15] P. Cochat,et al. Et al , 2008, Archives de pediatrie : organe officiel de la Societe francaise de pediatrie.

[16] Jae Hyun Kim,et al. Experimental constraints on the spin and parity of the Z(4430) , 2007, 1306.4894.

[17] W. Hulsbergen,et al. Decay chain fitting with a Kalman filter , 2005, physics/0503191.

[18] A. Polosa,et al. Diquark-antidiquarks with hidden or open charm and the nature of X(3872) , 2004, hep-ph/0412098.

[19] M. Pivk,et al. SPlot: A Statistical tool to unfold data distributions , 2004, physics/0402083.

[20] H. Lipkin,et al. A diquark–triquark model for the KN pentaquark , 2003, hep-ph/0402260.

[21] F. Wilczek,et al. Diquarks and exotic spectroscopy. , 2003, Physical review letters.

[22] D. Strottman. Multi - Quark Baryons and the MIT Bag Model , 1979 .

[23] G. Veneziano,et al. A possible description of baryon dynamics in dual and gauge theories , 1977 .

[24] Stanley M. Flatte,et al. Coupled-channel analysis of the πη and KK̄ systems near KK̄ threshold , 1976 .

[25] C. Quigg,et al. Centrifugal-barrier effects in resonance partial decay widths, shapes, and production amplitudes , 1972 .

[26] R. Dalitz,et al. CXII. On the analysis of τ-meson data and the nature of the τ-meson , 1953 .

[27] 刘翔,et al. Possible hidden-charm molecular baryons composed of an anti-charmed meson and a charmed baryon , 2012 .

[28] M. Snir,et al. Report No , 2005 .

[29] S. N.,et al. New Possibilities for Exotic Hadrons -anticharmed Strange Baryons ~" , 2002 .

[30] L. Okun,et al. Hadron Molecules and Charmonium Atom , 1976 .