Measurement of the mass and width of the Ds1(2536)+ meson

TL;DR

This paper precisely measures the mass and decay width of the Ds1(2536)+ meson using data from the BABAR detector, confirming its spin-parity and improving the accuracy of its known properties.

Contribution

The study provides the most precise measurements to date of the Ds1(2536)+ meson's mass, width, and mass difference, confirming its unnatural spin-parity.

Findings

Decay width measured as 0.92 ± 0.03 (stat) ± 0.04 (syst) MeV

Mass of the Ds1(2536)+ meson is 2535.08 ± 0.01 ± 0.15 MeV/c^2

Mass difference between Ds1+ and D*+ is 524.83 ± 0.01 ± 0.04 MeV/c^2

Abstract

The decay width and mass of the Ds1(2536)+ meson are measured via the decay channel Ds1+ -> D*+KS0 using 385 fb^-1 of data recorded with the BABAR detector in the vicinity of the Y(4S) resonance at the PEP-II asymmetric-energy electron-positron collider. The result for the decay width is 0.92 +- 0.03 (stat) +- 0.04 (syst) MeV. For the mass, a value of 2535.08 +- 0.01 +- 0.15 MeV/c^2 is obtained. The mass difference between the Ds1+ and the D*+ is measured to be 524.83 +- 0.01 +- 0.04 MeV/c^2, representing a significant improvement compared to the current world average. The unnatural spin-parity assignment for the Ds1+ meson is confirmed.