Evidence of a J/ψΛ structure and observation of excited Ξ- states in the Ξb                      -→J/ψΛK- decay

LHCb Collaboration

doi:10.1016/j.scib.2021.02.030

Evidence of a J/ψΛ structure and observation of excited Ξ^- states in the Ξ_b ^-→J/ψΛK^- decay

LHCb Collaboration

Physics and Astronomy

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Abstract

First evidence of a structure in the J/ψΛ invariant mass distribution is obtained from an amplitude analysis of Ξ_b ^-→J/ψΛK^- decays. The observed structure is consistent with being due to a charmonium pentaquark with strangeness with a significance of 3.1σ including systematic uncertainties and look-elsewhere effect. Its mass and width are determined to be 4458.8±2.9_-1.1 ^+4.7MeV and 17.3±6.5_-5.7 ^+8.0MeV, respectively, where the quoted uncertainties are statistical and systematic. The structure is also consistent with being due to two resonances. In addition, the narrow excited Ξ^- states, Ξ1690^- and Ξ1820^-, are seen for the first time in a Ξ_b ^- decay, and their masses and widths are measured with improved precision. The analysis is performed using pp collision data corresponding to a total integrated luminosity of 9 fb^-1, collected with the LHCb experiment at centre-of-mass energies of 7, 8 and 13 TeV.

Original language	English
Pages (from-to)	1278-1287
Number of pages	10
Journal	Science Bulletin
Volume	66
Issue number	13
Early online date	9 Mar 2021
DOIs	https://doi.org/10.1016/j.scib.2021.02.030
Publication status	Published - 15 Jul 2021

Bibliographical note

Funding Information:
The numerical calculations for this paper have been supported by the Supercomputing Center of Wuhan University. We express our gratitude to our colleagues in the CERN accelerator departments for the excellent performance of the LHC. We thank the technical and administrative staff at the LHCb institutes. We acknowledge support from CERN and from the national agencies: CAPES, CNPq, FAPERJ and FINEP (Brazil); MOST and NSFC (China); CNRS/IN2P3 (France); BMBF, DFG and MPG (Germany); INFN (Italy); NWO (Netherlands); MNiSW and NCN (Poland); MEN/IFA (Romania); MSHE (Russia); MICINN (Spain); SNSF and SER (Switzerland); NASU (Ukraine); STFC (United Kingdom); DOE NP and NSF (USA). We acknowledge the computing resources that are provided by CERN, IN2P3 (France), KIT and DESY (Germany), INFN (Italy), SURF (Netherlands), PIC (Spain), GridPP (United Kingdom), RRCKI and Yandex LLC (Russia), CSCS (Switzerland), IFIN–HH (Romania), CBPF (Brazil), PL-GRID (Poland) and OSC (USA). We are indebted to the communities behind the multiple open-source software packages on which we depend. Individual groups or members have received support from AvH Foundation (Germany); EPLANET, Marie Skłodowska-Curie Actions and ERC (European Union); A*MIDEX, ANR, Labex P2IO and OCEVU, and Région Auvergne-Rhône-Alpes (France); Key Research Program of Frontier Sciences of CAS, CAS PIFI, CAS CCEPP, Fundamental Research Funds for the Central Universities, and Sci. & Tech. Program of Guangzhou (China); RFBR, RSF and Yandex LLC (Russia); GVA, XuntaGal and GENCAT (Spain); the Royal Society and the Leverhulme Trust (United Kingdom).

Publisher Copyright:
© 2021 Science China Press

Keywords

Exotics
Particle and resonance production
Pentaquark
QCD
Quarkonium
Spectroscopy

ASJC Scopus subject areas

General

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Cite this

@article{2ab7d9682c064050bea985753c6bde22,

title = "Evidence of a J/ψΛ structure and observation of excited Ξ- states in the Ξb -→J/ψΛK- decay",

abstract = "First evidence of a structure in the J/ψΛ invariant mass distribution is obtained from an amplitude analysis of Ξb -→J/ψΛK- decays. The observed structure is consistent with being due to a charmonium pentaquark with strangeness with a significance of 3.1σ including systematic uncertainties and look-elsewhere effect. Its mass and width are determined to be 4458.8±2.9-1.1 +4.7MeV and 17.3±6.5-5.7 +8.0MeV, respectively, where the quoted uncertainties are statistical and systematic. The structure is also consistent with being due to two resonances. In addition, the narrow excited Ξ- states, Ξ1690- and Ξ1820-, are seen for the first time in a Ξb - decay, and their masses and widths are measured with improved precision. The analysis is performed using pp collision data corresponding to a total integrated luminosity of 9 fb-1, collected with the LHCb experiment at centre-of-mass energies of 7, 8 and 13 TeV.",

keywords = "Exotics, Particle and resonance production, Pentaquark, QCD, Quarkonium, Spectroscopy",

author = "{LHCb Collaboration} and R. Aaij and {Abell{\'a}n Beteta}, C. and T. Ackernley and B. Adeva and M. Adinolfi and H. Afsharnia and Aidala, {C. A.} and S. Aiola and Z. Ajaltouni and S. Akar and J. Albrecht and F. Alessio and M. Alexander and {Alfonso Albero}, A. and Z. Aliouche and G. Alkhazov and {Alvarez Cartelle}, P. and S. Amato and Y. Amhis and L. An and L. Anderlini and A. Andreianov and M. Andreotti and F. Archilli and A. Artamonov and M. Artuso and K. Arzymatov and E. Aslanides and M. Atzeni and B. Audurier and S. Bachmann and M. Bachmayer and Back, {J. J.} and S. Baker and S. Bifani and R. Calladine and G. Chatzikonstantinidis and N. Cooke and V. Duk and N. Farley and P. Griffith and P. Ilten and Parkinson, {C. J.} and J. Plews and D. Popov and A. Sergi and Slater, {M. W.} and Swallow, {P. N.} and Watson, {N. K.} and Zarebski, {K. A.}",

note = "Funding Information: The numerical calculations for this paper have been supported by the Supercomputing Center of Wuhan University. We express our gratitude to our colleagues in the CERN accelerator departments for the excellent performance of the LHC. We thank the technical and administrative staff at the LHCb institutes. We acknowledge support from CERN and from the national agencies: CAPES, CNPq, FAPERJ and FINEP (Brazil); MOST and NSFC (China); CNRS/IN2P3 (France); BMBF, DFG and MPG (Germany); INFN (Italy); NWO (Netherlands); MNiSW and NCN (Poland); MEN/IFA (Romania); MSHE (Russia); MICINN (Spain); SNSF and SER (Switzerland); NASU (Ukraine); STFC (United Kingdom); DOE NP and NSF (USA). We acknowledge the computing resources that are provided by CERN, IN2P3 (France), KIT and DESY (Germany), INFN (Italy), SURF (Netherlands), PIC (Spain), GridPP (United Kingdom), RRCKI and Yandex LLC (Russia), CSCS (Switzerland), IFIN–HH (Romania), CBPF (Brazil), PL-GRID (Poland) and OSC (USA). We are indebted to the communities behind the multiple open-source software packages on which we depend. Individual groups or members have received support from AvH Foundation (Germany); EPLANET, Marie Sk{\l}odowska-Curie Actions and ERC (European Union); A*MIDEX, ANR, Labex P2IO and OCEVU, and R{\'e}gion Auvergne-Rh{\^o}ne-Alpes (France); Key Research Program of Frontier Sciences of CAS, CAS PIFI, CAS CCEPP, Fundamental Research Funds for the Central Universities, and Sci. & Tech. Program of Guangzhou (China); RFBR, RSF and Yandex LLC (Russia); GVA, XuntaGal and GENCAT (Spain); the Royal Society and the Leverhulme Trust (United Kingdom). Publisher Copyright: {\textcopyright} 2021 Science China Press ",

year = "2021",

month = jul,

day = "15",

doi = "10.1016/j.scib.2021.02.030",

language = "English",

volume = "66",

pages = "1278--1287",

journal = "Science Bulletin",

issn = "2095-9273",

publisher = "Springer Science + Business Media",

number = "13",

}

TY - JOUR

T1 - Evidence of a J/ψΛ structure and observation of excited Ξ- states in the Ξb -→J/ψΛK- decay

AU - LHCb Collaboration

AU - Aaij, R.

AU - Abellán Beteta, C.

AU - Ackernley, T.

AU - Adeva, B.

AU - Adinolfi, M.

AU - Afsharnia, H.

AU - Aidala, C. A.

AU - Aiola, S.

AU - Ajaltouni, Z.

AU - Akar, S.

AU - Albrecht, J.

AU - Alessio, F.

AU - Alexander, M.

AU - Alfonso Albero, A.

AU - Aliouche, Z.

AU - Alkhazov, G.

AU - Alvarez Cartelle, P.

AU - Amato, S.

AU - Amhis, Y.

AU - An, L.

AU - Anderlini, L.

AU - Andreianov, A.

AU - Andreotti, M.

AU - Archilli, F.

AU - Artamonov, A.

AU - Artuso, M.

AU - Arzymatov, K.

AU - Aslanides, E.

AU - Atzeni, M.

AU - Audurier, B.

AU - Bachmann, S.

AU - Bachmayer, M.

AU - Back, J. J.

AU - Baker, S.

AU - Bifani, S.

AU - Calladine, R.

AU - Chatzikonstantinidis, G.

AU - Cooke, N.

AU - Duk, V.

AU - Farley, N.

AU - Griffith, P.

AU - Ilten, P.

AU - Parkinson, C. J.

AU - Plews, J.

AU - Popov, D.

AU - Sergi, A.

AU - Slater, M. W.

AU - Swallow, P. N.

AU - Watson, N. K.

AU - Zarebski, K. A.

N1 - Funding Information: The numerical calculations for this paper have been supported by the Supercomputing Center of Wuhan University. We express our gratitude to our colleagues in the CERN accelerator departments for the excellent performance of the LHC. We thank the technical and administrative staff at the LHCb institutes. We acknowledge support from CERN and from the national agencies: CAPES, CNPq, FAPERJ and FINEP (Brazil); MOST and NSFC (China); CNRS/IN2P3 (France); BMBF, DFG and MPG (Germany); INFN (Italy); NWO (Netherlands); MNiSW and NCN (Poland); MEN/IFA (Romania); MSHE (Russia); MICINN (Spain); SNSF and SER (Switzerland); NASU (Ukraine); STFC (United Kingdom); DOE NP and NSF (USA). We acknowledge the computing resources that are provided by CERN, IN2P3 (France), KIT and DESY (Germany), INFN (Italy), SURF (Netherlands), PIC (Spain), GridPP (United Kingdom), RRCKI and Yandex LLC (Russia), CSCS (Switzerland), IFIN–HH (Romania), CBPF (Brazil), PL-GRID (Poland) and OSC (USA). We are indebted to the communities behind the multiple open-source software packages on which we depend. Individual groups or members have received support from AvH Foundation (Germany); EPLANET, Marie Skłodowska-Curie Actions and ERC (European Union); A*MIDEX, ANR, Labex P2IO and OCEVU, and Région Auvergne-Rhône-Alpes (France); Key Research Program of Frontier Sciences of CAS, CAS PIFI, CAS CCEPP, Fundamental Research Funds for the Central Universities, and Sci. & Tech. Program of Guangzhou (China); RFBR, RSF and Yandex LLC (Russia); GVA, XuntaGal and GENCAT (Spain); the Royal Society and the Leverhulme Trust (United Kingdom). Publisher Copyright: © 2021 Science China Press

PY - 2021/7/15

Y1 - 2021/7/15

N2 - First evidence of a structure in the J/ψΛ invariant mass distribution is obtained from an amplitude analysis of Ξb -→J/ψΛK- decays. The observed structure is consistent with being due to a charmonium pentaquark with strangeness with a significance of 3.1σ including systematic uncertainties and look-elsewhere effect. Its mass and width are determined to be 4458.8±2.9-1.1 +4.7MeV and 17.3±6.5-5.7 +8.0MeV, respectively, where the quoted uncertainties are statistical and systematic. The structure is also consistent with being due to two resonances. In addition, the narrow excited Ξ- states, Ξ1690- and Ξ1820-, are seen for the first time in a Ξb - decay, and their masses and widths are measured with improved precision. The analysis is performed using pp collision data corresponding to a total integrated luminosity of 9 fb-1, collected with the LHCb experiment at centre-of-mass energies of 7, 8 and 13 TeV.

AB - First evidence of a structure in the J/ψΛ invariant mass distribution is obtained from an amplitude analysis of Ξb -→J/ψΛK- decays. The observed structure is consistent with being due to a charmonium pentaquark with strangeness with a significance of 3.1σ including systematic uncertainties and look-elsewhere effect. Its mass and width are determined to be 4458.8±2.9-1.1 +4.7MeV and 17.3±6.5-5.7 +8.0MeV, respectively, where the quoted uncertainties are statistical and systematic. The structure is also consistent with being due to two resonances. In addition, the narrow excited Ξ- states, Ξ1690- and Ξ1820-, are seen for the first time in a Ξb - decay, and their masses and widths are measured with improved precision. The analysis is performed using pp collision data corresponding to a total integrated luminosity of 9 fb-1, collected with the LHCb experiment at centre-of-mass energies of 7, 8 and 13 TeV.

KW - Exotics

KW - Particle and resonance production

KW - Pentaquark

KW - QCD

KW - Quarkonium

KW - Spectroscopy

UR - http://www.scopus.com/inward/record.url?scp=85104149325&partnerID=8YFLogxK

U2 - 10.1016/j.scib.2021.02.030

DO - 10.1016/j.scib.2021.02.030

M3 - Article

AN - SCOPUS:85104149325

SN - 2095-9273

VL - 66

SP - 1278

EP - 1287

JO - Science Bulletin

JF - Science Bulletin

IS - 13

ER -

Evidence of a J/ψΛ structure and observation of excited Ξ- states in the Ξb -→J/ψΛK- decay