APS » Journals » Phys. Rev. Lett. » Accepted Papers » Measurement of the $\Lambda_b^0$, $\Xi_b^-$, and $\Omega_b^-$ baryon masses

Measurement of the \Lambda_b^0, \Xi_b^-, and \Omega_b^- baryon masses

Accepted

---------------- Bottom baryons decaying to a meson and a hyperon are reconstructed using 1.0 fb-1 of data collected in 2011 with the LHCb detector. Significant \myLb\jpsi\myL, \myXb\jpsi\myX and \myOb\jpsi\myO signals are observed and the corresponding masses are measured to be M(\myLb)  = 5619.53    0.13  (stat)  0.45  (syst) MeV/c2, M(\myXb)  = 5795.8    0.9  (stat)  0.4  (syst) MeV/c2, M(\myOb)  = 6046.0    2.2  (stat)  0.5  (syst) MeV/c2, while the differences with respect to the mass are M(\myXb) -M(\myLb)  = 176.2    0.9  (stat)  0.1  (syst) MeV/c2, M(\myOb) -M(\myLb)  = 426.4    2.2  (stat)  0.4  (syst) MeV/c2. These are the most precise mass measurements of the , and baryons to date. Averaging the above mass measurement with that published by  using 35 pb-1 of data collected in 2010 yields M(\myLb) = 5619.44 0.13 (stat)0.38 (syst) .