%0 Journal Article
%T Observation of Two New Xi(-)(b) Baryon Resonances
%A LHCb Collaboration (Aaij, R. et al
%A Martinez-Vidal, F.
%A Oyanguren, A.
%A Ruiz Valls, P.
%A Sanchez Mayordomo, C.
%J Physical Review Letters
%D 2015
%V 114
%N 6
%I Amer Physical Soc
%@ 0031-9007
%G English
%F LHCbCollaborationAaij_etal2015
%O WOS:000349490200004
%O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=2127), last updated on Fri, 20 Mar 2015 09:27:31 +0000
%X Two structures are observed close to the kinematic threshold in the Xi(0)(b)pi(-) mass spectrum in a sample of proton-proton collision data, corresponding to an integrated luminosity of 3.0 fb(-1), recorded by the LEICb 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 Xi'(-)(b) and Xi*(-)(b). Interpreting the structures as these resonances, we measure the mass differences and the width of the heavier state to be m(Xi'(-)(b)) – m(Xi(0)(b)) – m(pi(-))=3.653 +/- 0.018 +/- 0.006 MeV/c(2), m(Xi*(-)(b)) – m(Xi(0)(b)) – m(pi(-)) = 23.96 +/- 0.12 +/- 0.06 MeV/e(2), Gamma(Xi*(-)(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 Gamma(Xi'(-)(b)) < 0.08 MeV at 95% confidence level. Relative production rates of these states are also reported.
%R 10.1103/PhysRevLett.114.062004
%U http://arxiv.org/abs/1411.4849
%U https://doi.org/10.1103/PhysRevLett.114.062004
%P 062004-9pp