Recent lattice QCD calculations from the HAL and NPLQCD Collaborations have
reported evidence for the existence of a bound state with strangeness -2 and
baryon number 2 at quark masses somewhat higher than the physical values. A
controlled chiral extrapolation of these lattice results to the physical point
suggested that the state, identified with the famed H dibaryon, is most likely
slightly unbound (by 13 Β± 14 MeV) with respect to the ΞββΞ
threshold. We report the results of an updated analysis which finds the H
unbound by 26 Β± 11 MeV. Apart from the insight it would give us into how
QCD is realized in Nature, the H is of great interest because of its potential
implications for the equation of state of dense matter and studies of neutron
stars. It may also explain the enhancement above the ΞββΞ
threshold already reported experimentally. It is clearly of great importance
that the latter be pursued in experiments at the new J-PARC facility.Comment: Invited presentation at APPC12 (12th Asia Pacific Physics
Conference), July 14-19, 2013, Chiba, Japa