Observation of Ds1(2536)+ -> D+pi-K+ and angular decomposition of Ds1(2536)+ -> D*+K0S

TL;DR

This paper reports the first observation of the decay Ds1(2536)+ -> D+pi-K+ and analyzes its angular distribution, revealing the dominance of the S-wave component and providing precise measurements of branching ratios and amplitude ratios.

Contribution

First observation of the decay Ds1(2536)+ -> D+pi-K+ and detailed angular analysis of Ds1(2536)+ -> D*+K0S decay with amplitude ratio measurements.

Findings

Measured branching ratio B(Ds1+ -> D+pi-K+)/B(Ds1+ -> D*+K0) = (3.27+-0.18+-0.37)%

S-wave amplitude dominates with Gamma_S/Gamma_total=0.72+-0.05+-0.01

Angular distributions support S-wave dominance in decay

Abstract

Using 462/fb of e+e- annihilation data recorded by the Belle detector, we report the first observation of the decay Ds1(2536)+ -> D+pi-K+. The ratio of branching fractions B(Ds1+ -> D+pi-K+)/B(Ds1+ -> D*+K0) is measured to be (3.27+-0.18+-0.37)%. We also study the angular distributions in the Ds1(2536)+ -> D*+K0S decay and measure the ratio of D- and S-wave amplitudes. The S-wave dominates, with a partial width of Gamma_S/Gamma_total=0.72+-0.05+-0.01.