PT Journal
AU LHCb Collaboration (Aaij, Rea
   Jaimes Elles, SJ
   Jashal, BK
   Martinez-Vidal, F
   Oyanguren, A
   Rebollo De Miguel, M
   Remon Alepuz, C
   Ruiz Vidal, J
   Sanderswood, I
TI Observation of a Resonant Structure near the Ds+Ds- Threshold in the B+ -> Ds+Ds- K+ Decay
SO Physical Review Letters
JI Phys. Rev. Lett.
PY 2023
BP 071901
EP 12pp
VL 131
IS 7
DI 10.1103/PhysRevLett.131.071901
LA English
AB An amplitude analysis of the B thorn & RARR; D thorn s D-s K thorn decay is carried out to study for the first time its intermediate resonant contributions, using proton-proton collision data collected with the LHCb detector at center-of-mass energies of 7, 8, and 13 TeV. A near-threshold peaking structure, referred to as X(3960), is observed in the D thorn s D-s invariant-mass spectrum with significance greater than 12 standard deviations. The mass, width, and the quantum numbers of the structure are measured to be 3956 1 5 1 10 MeV, 43 1 13 1 8 MeV, and JPC = 0 thorn thorn , respectively, where the first uncertainties are statistical and the second systematic. The properties of the new structure are consistent with recent theoretical predictions for a state composed of cc over bar ss over bar quarks. Evidence for an additional structure is found around 4140 MeV in the D thorn s D-s invariant mass, which might be caused either by a new resonance with the 0 thorn thorn assignment or by a J=& psi;& phi; & LRARR; D thorn s D-s coupled-channel effect.
ER