First evid.nce of a structure in the J/ψΛinvariant mass d.stribution is obtained.from an amplitud. analysis of■b^(-)J/ψΛK^(-)*** observed.structure is consistent with being d.e to a charmonium pentaquark with str...
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First evid.nce of a structure in the J/ψΛinvariant mass d.stribution is obtained.from an amplitud. analysis of■b^(-)J/ψΛK^(-)*** observed.structure is consistent with being d.e to a charmonium pentaquark with strangeness with a significance of 3.1r includ.ng systematic uncertainties and.lookelsewhere *** mass and.wid.h are d.termined.to be 4458:8±2:9t4:7-1:1 MeV and.17:3±6:5t8:0-5:7 MeV,respectively,where the quoted.uncertainties are statistical and.*** structure is also consistent with being d.e to two *** ad.ition,the narrow excited.^(-)states,N■(1690)and.(1820),are seen for the first time in a■b^(-)d.cay,and.their masses and.wid.hs are measured.with improved.*** analysis is performed.using pp collision d.ta correspond.ng 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.
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