2014/11/30 by LHCb collaboration, R. Aaij, B. Adeva +707 · 1 citation
Chemistry · Physics and Astronomy · #Analytical Chemistry (journal) #Baryon #Chemistry #High-Energy Particle Collisions Research #Luminosity #Nuclear physics #Particle physics #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #Quantum mechanics #Quark #hep-ex
paper · pdf · doi:10.1103/physrevlett.114.062004
published as Phys. Rev. Lett. 114, 062004 (2015) · 17 pages, 2 figures
openalex publication_date 2015/02/10 · arxiv created 2015/02/16 · arxiv updated 2015/03/04 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
Two structures are observed close to the kinematic threshold in the Ξ(b)(0)π(-) mass spectrum in a sample of proton-proton collision data, corresponding to an integrated luminosity of 3.0 fb(-1), recorded by the LHCb experiment. In the quark model, two baryonic resonances with quark content bds are expected in this mass region: the spin-parity J(P)=(1/2)(+) and J(P)=(3/2)(+) states, denoted Ξ(b)('-) and Ξ(b)(*-). Interpreting the structures as these resonances, we measure the mass differences and the width of the heavier state to be m(Ξ(b)('-))-m(Ξ(b)(0))-m(π(-))=3.653±0.018±0.006 MeV/c(2), m(Ξ(b)(*-))-m(Ξ(b)(0))-m(π(-))=23.96±0.12±0.06 MeV/c(2), Γ(Ξ(b)(*-))=1.65±0.31±0.10 MeV, where the first and second uncertainties are statistical and systematic, respectively. The width of the lighter state is consistent with zero, and we place an upper limit of Γ(Ξ(b)('-))<0.08 MeV at 95% confidence level. Relative production rates of these states are also reported.