Measurement of $\psip$ Radiative Decays

TL;DR

This paper reports the first measurements of various branching fractions for psi(2S) radiative decays into specific hadronic final states using 14 million events at BESII, providing new data on charmonium decay modes.

Contribution

It provides the first measurements and upper limits of branching fractions for multiple psi(2S) radiative decay channels into hadrons, expanding understanding of charmonium decay processes.

Findings

Measured branching fractions for several decay modes.

Established upper limits for some decay channels.

Enhanced data on psi(2S) radiative decay patterns.

Abstract

Using 14 million psi(2S) events accumulated at the BESII detector, we report first measurements of branching fractions or upper limits for psi(2S) decays into gamma ppbar, gamma 2(pi^+pi^-), gamma K_s K^-pi^++c.c., gamma K^+ K^- pi^+pi^-, gamma K^{*0} K^- pi^+ +c.c., gamma K^{*0}\bar K^{*0}, gamma pi^+pi^- p pbar, gamma 2(K^+K^-), gamma 3(pi^+pi^-), and gamma 2(pi^+pi^-)K^+K^- with the invariant mass of hadrons below 2.9GeV/c^2. We also report branching fractions of psi(2S) decays into 2(pi^+pi^-) pi^0, omega pi^+pi^-, omega f_2(1270), b_1^\pm pi^\mp, and pi^0 2(pi^+pi^-) K^+K^-.