2023/09/08 by Rigo Bause, Bause, Rigo, Hector Gisbert +9
Physics and Astronomy · Computer Science · #Particle physics theoretical and experimental studies #Computational Physics and Python Applications #Dark Matter and Cosmic Phenomena
paper · pdf · doi:10.48550/arxiv.2309.04513
The recent LHCb determination of the direct CP asymmetries in the decays D0 → K+ K-, π+ π- hints at a sizeable breaking of two approximate symmetries of the SM: CP and U-spin. We aim at explaining the data with BSM physics and use the framework of flavorful Z^′ models. Interestingly, experimental and theoretical constraints very much narrow down the shape of viable models: Viable, anomaly-free models are electron- and muon-phobic and feature a light Z^′ of 10-20 GeV coupling only to right-handed fermions. The Z^′ can be searched for in low mass dijets or at the LHC as well as dark photon searches. A light Z^′ of ∼ 3 GeV or ∼ 5-7 GeV can moreover resolve the longstanding discrepancy in the J/ψ, ψ^′ branching ratios with pion form factors from fits to e+ e- → π+ π- data, and simultaneously explain the charm CP asymmetries. Smoking gun signatures for this scenario are Υ and charmonium decays into pions, taus or invisbles.