Lattice QCD study of doubly charmed strange baryons

We present the energy spectra of the low-lying doubly charmed baryons using lattice quantum chromodynamics. We precisely predict the ground state mass of the charmed-strange ${\mathrm{\Omega }}_{cc}(1/2^{+})$ baryon to be 3712(11)(12) MeV which could well be the next doubly charmed baryon to be discovered at the LHCb experiment at CERN. We also predict masses of other doubly charmed strange baryons with quantum numbers $3/2^{+}$, $1/2^{-}$, and $3/2^{-}$.

Figure 1

(Top) Effective mass plot of the ground state of ${\mathrm{\Omega }}_{cc}(1/2^{+})$ baryon (in arbitrary units) corresponding to relativistic operator, and (Bottom) effective hyperfine splitting (in units of MeV) on fine lattice.

Figure 2

Ground state mass of ${\mathrm{\Omega }}_{cc}(1/2^{+})$ baryon at three lattice spacings are shown in terms of (top) energy splittings from the spin-average mass [Eq. (2)] and (bottom) the ratio with the spin-average mass [Eq. (4)]. Continuum extrapolated values are also shown by the star symbol. Two cases are for HQET (upper) and relativistic (lower) interpolators.

Figure 3

Hyperfine splitting between $3/2^{+}$ and $1/2^{+}$ ${\mathrm{\Omega }}_{cc}$ baryons are shown at three lattice spacings and at the continuum limit. Bands represent one sigma-errors in fits with quadratic and logarithmic forms in lattice spacing.

Figure 4

Comparison of hyperfine splitting between the ground states of $3/2^{+}$ and $1/2^{+}$ baryons obtained from various theoretical calculations. Continuum extrapolated results are shown by symbols with red color while symbols with all other colors are obtained only at one lattice spacing.

Figure 5

Ground state mass of (top) ${\mathrm{\Omega }}_{cc}(1/2^{-})$ and (bottom) ${\mathrm{\Omega }}_{cc}(3/2^{-})$ at three lattice spacings are plotted in terms of the energy splittings from the spin-average mass [Eq. (2)].

Figure 6

Energy spectra of the low-lying ${\mathrm{\Omega }}_{cc}(ccs)$ baryons obtained from different lattice calculations and a recent quark model calculation. Our results are represented as ILGTI (this calculation) and HSC (previous calculation). Continuum extrapolated results are shown by symbols with red color while symbols with all other colors are obtained only at one lattice spacing.