Multi muon/anti-muon signals via productions of gauge and scalar bosons in a $$U(1)_{L_\mu - L_\tau }$$ model at muonic colliders

Abstract

AbstractWe discuss the discovery potential of a promising signals, $$3 \times \mu ^+ \mu ^-$$ 3 × μ + μ - at a $$\mu ^+ \mu ^-$$ μ + μ - collider and $$\mu ^+ \mu ^+ \mu ^+ \mu ^+ \mu ^- \mu ^- $$ μ + μ + μ + μ + μ - μ - at a $$\mu ^+ \mu ^+$$ μ + μ + collider, that are obtained via production of $$Z'$$ Z ′ and a new scalar boson $$\phi $$ ϕ in a spontaneously broken local $$U(1)_{L_\mu - L_\tau }$$ U ( 1 ) L μ - L τ model. We consider the $$Z'$$ Z ′ associated production from the process $$\mu ^+ \mu ^- \rightarrow \phi Z'$$ μ + μ - → ϕ Z ′ in addition to a muonphilic $$Z'$$ Z ′ fusion process $$\mu ^+ \mu ^\pm \rightarrow \phi \mu ^+ \mu ^\pm $$ μ + μ ± → ϕ μ + μ ± . The scalar boson is associated with $$U(1)_{L_\mu - L_\tau }$$ U ( 1 ) L μ - L τ symmetry breaking and dominantly decays into $$Z' Z'$$ Z ′ Z ′ mode. We carry out numerical simulation analysis for signal and background processes to estimate a discovery significance for different benchmark points. It is shown that our signal can be observed with integrated luminosity less than $$\mathcal {O}(100)$$ O ( 100 ) fb$$^{-1}$$ - 1 for both $$\mu ^+ \mu ^-$$ μ + μ - and $$\mu ^+ \mu ^+$$ μ + μ + colliders with more than 5-$$\sigma $$ σ significance.