Search for the decay Bs0 → η' Xss̄ Using a Semi-Inclusive Method at the Belle Experiment

Abstract

The decay Bs0 → η' Xss̄ is searched for at Belle, using Belle’s 121.4/fbintegrated luminosity data sample, taken at Υ(5S) resonance. A semi- inclusive reconstruction method whereby the Xss̄ is reconstructed as a system of two kaons and up to four pions, with at most one neutral pion, is used. Using the η' sub-decay mode η'→ η (→ γγ ) π+ π− and examining the Xss̄ mass range M( Xss̄ ) ≤ 2.4 GeV/c^2 , an upper limit at 90% confidence level is set. This mode had been previously unstudied and this analysis partially hopes to motivate future theoretical studies as well as future analyses at the Belle II experiment.