Precision measurement of D meson mass differences

TL;DR

This paper reports precise measurements of D meson mass differences and the D^0 mass using decay modes in proton-proton collisions at 7 TeV, achieving improved accuracy over previous results.

Contribution

The study provides the most precise measurements to date of D meson mass differences and the D^0 mass using large LHCb data and specific decay channels.

Findings

D^0 mass measured as 1864.75 ± 0.15 (stat) ± 0.11 (syst) MeV/c^2

Mass difference M(D^+) - M(D^0) is 4.76 ± 0.12 (stat) ± 0.07 (syst) MeV/c^2

Mass difference M(D_s^+) - M(D^+) is 98.68 ± 0.03 (stat) ± 0.04 (syst) MeV/c^2

Abstract

Using three- and four-body decays of $D$ mesons produced in semileptonic $b$-hadron decays, precision measurements of $D$ meson mass differences are made together with a measurement of the $D^{0}$ mass. The measurements are based on a dataset corresponding to an integrated luminosity of $1.0 fb^{-1}$ collected in $pp$ collisions at 7\,TeV. Using the decay $D^0 \rightarrow K^{+} K^{-} K^{-} \pi^{+}$, the $D^0$ mass is measured to be $M(D^0) &=& 1864.75 \pm 0.15 \,({\rm stat}) \pm 0.11 \,({\rm syst}) \, \textrm{MeV/c^2}$. The mass differences $M(D^{+}) - M(D^{0}) = 4.76 \pm 0.12 \,({\rm stat}) \pm 0.07 \,({\rm syst}) \, \textrm{MeV/c^2}$ and $M(D^{+}_s) - M(D^{+}) = 98.68 \pm 0.03 \,({\rm stat}) \pm 0.04 \,({\rm syst}) \, \textrm{MeV/c^2}$ are measured using the $D^0 \rightarrow K^{+} K^{-} \pi^{+} \pi^{-}$ and $D^{+}_{(s)} \rightarrow K^{+}K^{-} \pi^{+}$ modes.