Measurement of the B0_s semileptonic branching ratio to an orbitally excited D_s** state, Br(B0_s -> Ds1(2536) mu nu)

TL;DR

This paper reports the first measurement of the semileptonic branching ratio of B0_s decays to the excited D_s** state, using data from the D0 detector to observe and analyze the D_s1(2536) state.

Contribution

It provides the first measurement of the branching ratio for B0_s decays to D_s1(2536) mu nu, advancing understanding of B0_s semileptonic decay modes.

Findings

Observation of D_s1(2536) with measured mass 2535.7 MeV

Measurement of the product of branching ratios involving D_s1(2536)

Extraction of the semileptonic branching ratio Br(B0_s -> D_s1(2536) mu nu)

Abstract

In a data sample of approximately 1.3 fb-1 collected with the D0 detector between 2002 and 2006, the orbitally excited charm state D_s1(2536) has been observed with a measured mass of 2535.7 +/- 0.6 (stat) +/- 0.5 (syst) MeV via the decay mode B0_s -> D_s1(2536) mu nu X. A first measurement is made of the branching ratio product Br(b(bar) -> D_s1(2536) mu nu X).Br(D_s1(2536)->D* K0_S). Assuming that D_s1(2536) production in semileptonic decay is entirely from B0_s, an extraction of the semileptonic branching ratio Br(B0_s -> D_s1(2536) mu nu X) is made.