Measurement of the D*(2010)+ natural line width and the D*(2010)+ - D0 mass difference

TL;DR

This paper precisely measures the natural line width and mass difference between D*(2010)+ and D0 mesons using BABAR data, improving the accuracy of these fundamental parameters.

Contribution

The study provides the most precise measurements to date of the D*(2010)+ width and mass difference, refining previous experimental results.

Findings

Width measured as approximately 83.3 keV with improved precision.

Mass difference determined as approximately 145,426 keV with higher accuracy.

Width is about 12 times more precise than previous measurements.

Abstract

We measure the mass difference, \Delta m_0, between the D*(2010)+ and the D0 and the natural line width, \Gamma, of the transition D*(2010)+ -> D0 pi+. The data were recorded with the BABAR detector at center-of-mass energies at and near the Upsilon(4S) resonance, and correspond to an integrated luminosity of approximately 477 1/fb. The D0 is reconstructed in the decay modes D0 -> K- pi+ and D0 -> K- pi+ pi- pi+. For the decay mode D0 -> K- pi+ we obtain Gamma = (83.4 +- 1.7 +- 1.5) keV and \Delta m_0 = (145 425.6 +- 0.6 +- 1.8) keV, where the quoted errors are statistical and systematic, respectively. For the D0 -> K- pi+ pi- pi+ mode we obtain \Gamma = (83.2 +- 1.5 +- 2.6) keV and \Delta m_0 = (145 426.6 +- 0.5 +- 2.0) keV. The combined measurements yield \Gamma = (83.3 +- 1.2 +- 1.4) keV and \Delta m_0 = (145 425.9 +- 0.4 +- 1.7) keV; the width is a factor of approximately 12 times more precise than the previous value, while the mass difference is a factor of approximately 6 times more precise.