Measurement of the D∗(2010)+−D+ Mass Difference

Abstract

We measure the mass difference, Δ m + , between the D ∗ ( 2010 ) + and the D + using the decay chain D ∗ ( 2010 ) + → D + π 0 with D + → K − π + π + . The data were recorded with the BABAR detector at center-of-mass energies at and near the Υ ( 4 S ) resonance, and correspond to an integrated luminosity of approximately 468 fb − 1 . We measure Δ m + = ( 140 601.0 ± 6.8 [ stat ] ± 12.9 [ syst ] ) keV . We combine this result with a previous BABAR measurement of Δ m 0 ≡ m ( D ∗ ( 2010 ) + ) − m ( D 0 ) to obtain Δ m D = m ( D + ) − m ( D 0 ) = ( 4824.9 ± 6.8 [ stat ] ± 12.9 [ syst ] ) keV . These results are compatible with and approximately five times more precise than the Particle Data Group averages.