Measurement of the decay ${\eta }^{\prime }\to {\pi }^0{\pi }^0\eta$ at MAMI

Abstract

An experimental study of the ${\eta }^{\prime }\to {\pi }^0{\pi }^0\eta \to 6\gamma$ decay has been conducted with the best up-to-date statistical accuracy, by measuring ${\eta }^{\prime }$ mesons produced in the $\gamma p\to {\eta }^{\prime }p$ reaction with the A2 tagged-photon facility at the Mainz Microtron, MAMI. The results obtained for the standard parametrization of the ${\eta }^{\prime }\to {\pi }^0{\pi }^0\eta$ matrix element are consistent with the most recent results for ${\eta }^{\prime }\to \pi \pi \eta$ decays, but have smaller uncertainties. The available statistics and experimental resolution allowed, for the first time, an observation of a structure below the ${\pi }^{+}{\pi }^{-}$ mass threshold, the magnitude and sign of which, checked within the framework of the nonrelativistic effective-field theory, demonstrated good agreement with the cusp that was predicted based on the $\pi \pi$ scattering length combination, $a_0-a_2$, extracted from $K\to 3\pi$ decays.

arXiv comment15 pages, 8 figures, 2 tables, accepted for publication in Phys. Rev. D

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• ππscattering
• Large N_c in chiral perturbation theory
• Cusps in K --> 3 pi decays
• Study of the gp-->etap reaction with the Crystal Ball detector at the Mainz Microtron(MAMI-C)
• 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
• Electromagnetic corrections in eta --> 3 pi decays
• Radiative corrections in K --> 3 pi decays
• Measurement of the Slope Parameter $\alpha$ for the $\eta \to 3{\pi }^0$ decay with the Crystal Ball detector at the Mainz Microtron (MAMI-C)
• Cusps in K_L --> 3 pi decays
• Study of $\eta$ and ${\eta }^{\prime }$ photoproduction at MAMI
• Determination of the Dalitz plot parameter alpha for the decay eta->3pi^0 with the Crystal Ball at MAMI-B
• Measurement of pi^0 photoproduction on the proton at MAMI C
• 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 eta->3pi0 Dalitz Plot Distribution with the WASA Detector at COSY
• Measurement of the Matrix Element for the Decay ${\eta }^{\prime }\to \eta {\pi }^{+}{\pi }^{-}$
• Study of ${\eta }^{\prime }\to \eta {\pi }^{+}{\pi }^{-}$ Dalitz plot
• Predictions for the cusp in eta->3pi0 decay
• Rare Decays of the ${\eta }^{{}^{\prime }}$
• Detailed Study of the KL -> 3pi0 Dalitz Plot
• Measurement of the matrix elements for the decays ${\eta }^{\prime }\to \eta {\pi }^{+}{\pi }^{-}$ and ${\eta }^{\prime }\to \eta {\pi }^0{\pi }^0$
• $\eta$-${\eta }^{\prime }$ Mixing in Large-$N_c$ Chiral Perturbation Theory
• Chiral Nonet Mixing in ${\eta }^{\prime }\to \eta \pi \pi$ Decay

Cited by in corpus (6)

• Precision tests of fundamental physics with $\eta$ and ${\eta }^{\prime }$ mesons
• What can we learn about light-meson interactions at electron-positron colliders?
• ${\eta }^{\prime }\to \eta \pi \pi$ decays in unitarized resonance chiral theory
• 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
• Evidence for the Cusp Effect in ${\eta }^{\prime }$ Decays into $\eta {\pi }^0{\pi }^0$