Evidence for Decays of h_c to Multi-Pion Final States

TL;DR

This paper reports the first evidence for the decay of h_c to multi-pion final states, measuring the product branching fraction and comparing it to other decay modes, using data from psi(2S) decays.

Contribution

It provides the first evidence for h_c decaying into multi-pion final states and measures the associated branching fraction, expanding understanding of h_c decay channels.

Findings

First evidence for h_c -> 2(pi^+ pi^-) pi^0 decay

Measured product branching fraction: 1.88 x 10^{-5}

h_c -> hadrons and h_c -> gamma eta_c have similar rates

Abstract

Using a sample of 2.59 x 10^7$ psi(2S) decays collected by the CLEO--c detector, we present results of a search for the decay chain psi(2S) -> pi^0 h_c, h_c -> n(pi^+ pi^-) pi^0, n=1,2,3. We observe no significant signals for n=1 and n=3 and set upper limits for the corresponding decay rates. First evidence for the decay h_c {\o}pi^+ pi^- pi^+ pi^- pi^0 is presented, and a product branching fraction of B(psi(2S) -> h_c) x B(h_c -> 2(pi^+ pi^-) pi^0)=1.88^{+0.48+0.47}_{-0.45-0.30} x 10^{-5} is measured. This result implies that h_c -> $ hadrons and h_c -> gamma eta_c have comparable rates, in agreement with expectations.