2011/11/30 by Jinlin Fu, JINLIN FU, Hai-Bo Li +5
Computer Science · Physics and Astronomy · #Computational Physics and Python Applications #Dark Matter and Cosmic Phenomena #Particle physics theoretical and experimental studies #hep-ex #hep-ph
paper · pdf · doi:10.1142/s0217732312502239
6 pages, 3 figure, add two more figures, more discussions
arxiv created 2012/05/16 · openalex publication_date 2012/11/25 · arxiv updated 2012/12/03 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We study the electromagnetic Dalitz decay modes of J/ψ → P l + l - (P = π 0 , η or η′). In these decays, the lepton pairs are formed by internal conversion of an intermediate virtual photon with invariant mass m l + l - . Study of the effective-mass spectrum of the l + l - will shed light on the dynamic transition form factor [Formula: see text], which characterizes the electromagnetic structure arising at the vertex of the transition J/ψ to pseudoscalars. We also discuss the direct productions of a GeV scale vector U boson in these processes J/ψ → PU (U → l + l - ). It is responsible for mediating a new U(1) d interaction, as recently exploited in the context of weakly interacting massive particle dark matter. In this paper, we firstly use the usual pole approximation for the form factor to estimate the decay rate of J/ψ → P l + l - in the Standard Model. Then the reach of searching for the dark photon is estimated. We suggest that these Dalitz decays can be used to search for the light U boson in the BESIII experiment with a huge J/ψ data set.