Partial wave analysis of $\psi(2S) \to p \bar{p}\eta$

TL;DR

This study analyzes the decay of $oldsymbol{ ext{psi}(2S)}$ into $oldsymbol{p ar{p} ext{eta}}$ using BESIII data, identifying the dominant intermediate state N(1535) and measuring relevant branching fractions.

Contribution

First partial wave analysis of $ ext{psi}(2S) o p ar{p} ext{eta}$ decay, revealing N(1535) as the dominant intermediate state and providing precise branching fraction measurements.

Findings

N(1535) identified as dominant intermediate state

Measured branching fraction of $ ext{psi}(2S) o p ar{p} ext{eta}$

Determined product branching fraction involving N(1535)

Abstract

Using a sample of $1.06 \times 10^{8}$ $\psi(2S)$ events collected with the BESIII detector at BEPCII, the decay $\psi(2S) \to p \bar{p}\eta$ is studied. A partial wave analysis determines that the intermediate state N(1535) with a mass of $1524\pm5^{+10}_{-4}$ MeV/$c^2$ and a width of $130^{+27+57}_{-24-10}$ MeV/$c^2$ is dominant in the decay; the product branching fraction is determined to be $B(\psi(2S) \to N(1535)\bar{p})\times B(N(1535)\to p\eta)+c.c. = (5.2\pm0.3^{+3.2}_{-1.2})\times 10^{-5}$. Furthermore, the branching fraction of $\psi(2S) \to \eta p \bar{p}$ is measured to be $(6.4\pm0.2\pm0.6)\times 10^{-5}$.