Search for intermediate resonances and dark gauge bosons in $J/\psi \to \gamma {\pi }^0{\eta }^{\prime }$

Abstract

We report on an analysis of the decay $J/\psi \to \gamma {\pi }^0{\eta }^{\prime }$ using a sample of $(1310.6\pm 7.0)\times 10^{6}J/\psi$ events collected with the BESIII detector. We search for the CP-violating process ${\eta }_c\to {\pi }^0{\eta }^{\prime }$ and a dark gauge boson $U^{\prime }$ in $J/\psi \to U^{\prime }{\eta }^{\prime },U^{\prime }\to \gamma {\pi }^0,{\pi }^0\to \gamma \gamma$. No evidence of an ${\eta }_c$ signal is observed in the ${\pi }^0{\eta }^{\prime }$ invariant-mass spectrum and the upper limit of the branching fraction is determined to be $7.2\times 10^{-5}$ at the 90\% confidence level. We also find no evidence of $U^{\prime }$ production and set upper limits at the 90\% confidence level on the product branching fraction $\mathcal{B}(J/\psi \to U^{\prime }{\eta }^{\prime })\times \mathcal{B}(U^{\prime }\to {\pi }^0\gamma )$ in the range between $(0.8-6.5)\times 10^{-7}$ for 0.2 $\le m_{U^{\prime }}\le 2.1$GeV$/c^2$. In addition, we study the process $J/\psi \to \omega {\eta }^{\prime }$ with $\omega \to \gamma {\pi }^0$. The branching fraction of $J/\psi \to \omega {\eta }^{\prime }$ is found to be $(1.87\pm 0.09\pm 0.12)\times 10^{-4}$, where the first uncertainty is statistical and the second is systematic, with a precision that is improved by a factor of 1.4 over the previously published BESIII measurement.

References in corpus (24)

• 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
• Search for a dark photon in e+e- collisions at BABAR
• U-boson production in e+e- annihilations, psi and Upsilon decays, and Light Dark Matter
• Search for $A^{\prime }\to {\mu }^{+}{\mu }^{-}$ decays
• Dark matter search in missing energy events with NA64
• Search for hadronic transition ${\chi }_{cJ}\to {\eta }_c{\pi }^{+}{\pi }^{-}$ and observation of ${\chi }_{cJ}\to K\bar{K}\pi \pi \pi$
• New weakly-coupled forces hidden in low-energy QCD
• Constraints on Light Dark Matter and U bosons, from psi, Upsilon, K+, pi0, eta and eta' decays
• Proposal to search for a dark photon in $e^{+}$ on target collisions at DA$\Phi$NE linac
• Determination of the number of $J/\psi$ events with inclusive $J/\psi$ decays
• An amplitude analysis of the ${\pi }^0{\pi }^0$ system produced in radiative $J/\psi$ decays
• Dark Photon Search in the Mass Range Between 1.5 and 3.4 GeV/$c^2$
• Combined limit on the production of a light gauge boson decaying into ${\mu }^{+}{\mu }^{-}$ and ${\pi }^{+}{\pi }^{-}$
• U(1)_A symmetry in two-doublet models, U bosons or light scalars, and psi and Upsilon decays
• Observation of ${\eta }^{\prime }\to {\pi }^{+}{\pi }^{-}{\pi }^{+}{\pi }^{-}$ and ${\eta }^{\prime }\to {\pi }^{+}{\pi }^{-}{\pi }^0{\pi }^0$
• Measurement of $\mathcal{B}(J/\psi \to {\eta }^{\prime }{e}^{+}{e}^{-}$) and search for a dark photon
• Probing Dark force at BES-III/BEPCII
• Study of $J/\psi$ and $\psi (3686)$ decays to ${\pi }^{+}{\pi }^{-}{\eta }^{\prime }$
• Search for a dark vector gauge boson decaying to ${\pi }^{+}{\pi }^{-}$ using $\eta \to {\pi }^{+}{\pi }^{-}\gamma$ decays
• Search for CP and $P$ violating pseudoscalar decays into $\pi \pi$
• Measurement of branching fractions for $D$ meson decaying into $\varphi$ meson and a pseudoscalar meson
• A simulation study on the measurement of D0-D0bar mixing parameter y at BES-III

Cited by in corpus (1)

• Feebly-Interacting Particles:FIPs 2020 Workshop Report