Measurement of the matrix elements for the decays ${\eta }^{\prime }\to \eta {\pi }^{+}{\pi }^{-}$ and ${\eta }^{\prime }\to \eta {\pi }^0{\pi }^0$

Abstract

Based on a sample of $1.31\times 10^9$ $J/\psi$ events collected with the BESIII detector, the matrix elements for the decays ${\eta }^{\prime }\to \eta {\pi }^{+}{\pi }^{-}$ and ${\eta }^{\prime }\to \eta {\pi }^0{\pi }^0$ are determined using 351,016 ${\eta }^{\prime }\to (\eta \to \gamma \gamma ){\pi }^{+}{\pi }^{-}$ and 56,249 ${\eta }^{\prime }\to (\eta \to \gamma \gamma ){\pi }^0{\pi }^0$ events with background levels less than 1\%. Two commonly used representations are used to describe the Dalitz plot density. We find that an assumption of a linear amplitude does not describe the data well. A small deviation of the obtained matrix elements between ${\eta }^{\prime }\to \eta {\pi }^{+}{\pi }^{-}$ and ${\eta }^{\prime }\to \eta {\pi }^0{\pi }^0$ is probably caused by the mass difference between charged and neutral pions or radiative corrections. No cusp structure in ${\eta }^{\prime }\to \eta {\pi }^0{\pi }^0$ is observed.

arXiv comment11 pages, 7 figures

References in corpus (19)

• Design and Construction of the BESIII Detector
• The Precision Monte Carlo Event Generator KK For Two-Fermion Final States In e+e- Collisions
• Coherent Exclusive Exponentiation For Precision Monte Carlo Calculations
• Cusps in K --> 3 pi decays
• Determination of the a0-a2 pion scattering length from K->pi+ pi0 pi0 decay
• Pion-pion scattering and the K->3pi decay amplitudes
• Observation of a cusp-like structure in the pizero-pizero invariant mass distribution from K+- ==> pi+- pizero pizero decay and determination of the pi-pi scattering lengths
• Hadronic eta and eta-prime decays
• eta' to eta pi pi Decay as a Probe of a Possible Lowest-Lying Scalar Nonet
• Measurement of the Matrix Elements for the Decays $\eta \to {\pi }^{+}{\pi }^{-}{\pi }^0$ and $\eta /{\eta }^{\prime }\to {\pi }^0{\pi }^0{\pi }^0$
• The cusp effect in eta' --> eta pi pi decays
• Chiral dynamics predictions for eta' -> eta pi pi
• Dispersion relations for ${\eta }^{\prime }\to \eta \pi \pi$
• Hadronic decays of eta and eta-prime with coupled channels
• K -> 3 pi Final State Interactions at NLO in CHPT and Cabibbo's Proposal to Measure a_0-a_2
• Measurement of the Matrix Element for the Decay ${\eta }^{\prime }\to \eta {\pi }^{+}{\pi }^{-}$
• Study of ${\eta }^{\prime }\to \eta {\pi }^{+}{\pi }^{-}$ Dalitz plot
• Rare Decays of the ${\eta }^{{}^{\prime }}$
• Chiral Nonet Mixing in ${\eta }^{\prime }\to \eta \pi \pi$ Decay

Cited by in corpus (9)

• Precision measurement of the branching fractions of ${\eta }^{\prime }$ decays
• Dispersive construction of two-loop $P\to \pi \pi \pi$ $(P=K,\eta )$ amplitudes
• Patterns of $C$- and $CP$-violation in hadronic $\eta$ and ${\eta }^{\prime }$ three-body decays
• Search for the decay ${\eta }^{\prime }\to \gamma \gamma \eta$
• Measurement of the decay ${\eta }^{\prime }\to {\pi }^0{\pi }^0\eta$ at MAMI
• Search for the rare decay ${\eta }^{\prime }\to {\pi }^0{\pi }^0{\pi }^0{\pi }^0$ at BESIII
• Evidence for the Cusp Effect in ${\eta }^{\prime }$ Decays into $\eta {\pi }^0{\pi }^0$
• Novel method for determining the light quark mass ratio using ${\eta }^{\prime }\to \eta \pi \pi$ decays
• Measurement of the $\eta$ transition form factor through ${\eta }^{\prime }\to {\pi }^{+}{\pi }^{-}\eta$ decay