Lepton flavor violation in two-body decays of quarkonia

Abstract

In this paper we firstly study various model-independent bounds on lepton flavor violation (LFV) in processes of J/Ψ, Ψ ′ and Υ two-body decays, then calculate their branch ratios in models of the leptoquark, R violating MSSM and topcolor assisted technicolor(TC2) models.

Palatable leptoquark scenarios for lepton flavor violation in exclusive b → sℓ 1 ℓ 2 modes

“…Theoretically, the LFV decays are predicted in various NP scenarios, such as in models with heavy sterile fermions [1][2][3][4][5][6], in models with a peculiar breaking of supersymmetry [7][8][9][10], in models involving an extra Z -boson [11,12], and in multiple scenarios founded on the paradigm of existence of one or more leptoquark (LQ) states [13]. Most of the current experimental efforts in searching for the effects of LFV are focused onto lepton decays, 1 → 2 γ, 1 → 3 2 (with 1,2 ∈ {e, µ, τ }), and on the µ − e conversion in nuclei [14].…”

New gauge bosonZ′and lepton flavor violating decays and production of vector mesons

“…The general expression of the branching ratio Br(V → ℓ i ℓ j ) contributed by the new gauge boson Z ′ can be approximately written as [8] …”

“…Studying of lepton flavor violating (LFV) processes is an important tool to search for new physics beyond the SM. The LFV decays of the neutral vector mesons, such as ρ, ω, φ, J/Ψ, and Υ, unified called as V , have been studied in several new physics scenarios [8] and in a model-independent way [9]. It has been shown that the branching ratio Br(V → ℓ i ℓ j ) with ℓ i , ℓ j ∈ {e, µ, τ } can be significantly enhanced.…”

“…Where F V is the decay constant of the vector meson V with momentum p and in a polarization state σ, M V and ε σ µ express its mass and polarization vector, respectively. The general expression of the branching ratio Br(V → ℓ i ℓ j ) contributed by the new gauge boson Z ′ can be approximately written as [8]…”

Test of lepton universality and search for lepton flavor violation in ϒ(1S,2S,3S) decays at CLEO

“…On the other hand, many extensions of the Standard Model, such as GUT inspired models, supersymmetric models, and technicolor models, allow new scalar and vector bosons (leptoquarks, sleptons, Z') which can induce LFV decays [5]. In addition, LFV decays can be also triggered by low scale quantum gravity effects (or other new physics at the TeV scale) or by extra spacial dimensions [6].…”