Charmed-baryon spectroscopy from lattice QCD withNf=2+1+1flavors

Abstract

We present preliminary results of the calculation of the positive-parity ground state charm baryon spectrum using of N f = 2 + 1 + 1 dynamical quarks. The calculation uses a relativistic heavyquark action for the valence charm quark, clover-Wilson fermions for the valence light quarks and HISQ sea quarks. The spectrum is calculated with a lightest pion mass around 220 MeV and two lattice spacings (a ∼ 0.12 fm and 0.09 fm) are used to extrapolate to continuum limit. Our preliminary results are consistent with the currently measured baryon spectrum, except for the isospin-averaged J = 1/2 Ξ cc which is approximately 2 σ above the SELEX observed value. We predict the yet-to-be-discovered double and triple-charm baryons Ξ * cc , Ω cc , Ω * cc , Ω ccc to have masses 3665(42)(29) MeV, 3694(40)(45) MeV, 3739(35)(21) MeV and 4782(24)(28) MeV, respectively.

Spectroscopy of doubly charmed baryons from lattice QCD

“…al [40], and Briceno et. al [37] are extrapolated to the physical pion mass, while ILGTI [39] results are at pion mass 390 MeV. While the lattice spacing in the temporal direction (a t ) for this work is 0.0351 fm, for ETMC, a t = 0.056 fm, for PACS-CS, a t = 0.0899 fm, for Bali et.…”

“…Given this significance of doubly-charmed baryons, it is desirable to study these states comprehensively using lattice QCD. Lattice QCD groups have studied the ground states of the doubly-charmed baryons using quenched NRQCD [30], quenched QCD with relativistic quarks [31][32][33], and full QCD [34][35][36][37][38][39][40][41] calculations. However, all previous lattice calculations involve only the spin 1/2 and spin 3/2 ground state spectrum of Ξ cc and Ω cc .…”

Charmed baryons circa 2015

“…[56]. Figure 4 shows the results of recent lattice studies of doubly and triply charmed baryon spectra by different groups: RQCD [57], HSC [58], Brown et al [59], ETMC [60], ILGTI [61], PACS-CS [62], Durr et al [63], Briceno et al [64], Liu et al [65], and Na et al [66]. A new lattice calculation of Ω ( * ) cc and Ω ccc was available in Ref.…”

Heavy-hadron interactions from Lattice QCD

“…One of the highlights from recent years has been the prediction of the mass of the Ξ cc (and of a number of other charmed baryons) by various groups [26][27][28][29][30][31][32], which has been presented in Section 2.…”

“…A number of years ago, an isospin partner to this state has been claimed by the SELEX collaboration [18,19] Before the observation by the LHCb collaboration, a number of lattice calculations yielded predictions for the mass of Ξ cc in the isospin limit. The most advanced of these determinations [26][27][28][29][30][31] are collected in Figure 2, together with the state claimed by SELEX (green circle) and the observation by LHCb (magenta vertical band). While having a sizeable uncertainty, which largely stems from the limited set of gauge configurations, the various lattice determinations agree within uncertainties and the more precise determinations show considerable tension with the observation by SELEX, but agree quite well with the observed mass from LHCb.…”