Anomalous magnetic and weak magnetic dipole moments of the $$\tau $$ τ lepton in the simplest little Higgs model

Abstract

We obtain analytical expressions, both in terms of parametric integrals and Passarino-Veltman scalar functions, for the one-loop contributions to the anomalous weak magnetic dipole moment (AWMDM) of a charged lepton in the framework of the simplest little Higgs model (SLHM). Our results are general and can be useful to compute the weak properties of a charged lepton in other extensions of the standard model (SM). As a by-product we obtain generic contributions to the anomalous magnetic dipole moment (AMDM), which agree with previous results. We then study numerically the potential contributions from this model to the τ lepton AMDM and AWMDM for values of the parameter space consistent with current experimental data. It is found that they depend mainly on the energy scale f at which the global symmetry is broken and the t β parameter, whereas there is little sensitivity to a mild change in the values of other parameters of the model. While the τ AMDM is of the order of 10 −9 , the real (imaginary) part of its AWMDM is of the order of 10 −9 (10 −10 ). These values seem to be out of the reach of the expected experimental sensitivity of future experiments.

Flavor violation in chromo- and electromagnetic dipole moments induced by Z′ gauge bosons and a brief revisit of the Standard Model

“…To contextualize our results, we cite some predictions of a τ in some extended models. The estimations for a τ coming from two-Higgs doublet models [51], the minimal supersymmetric Standard Model [52], and the unparticle model [53] are of the order of 10 −6 , whereas for leptoquark models, a τ can be as high as 10 −8 [54], which coincides with the strongest prediction of the simplest little Higgs model [55].…”

Inclusive spin–momentum analysis and new physics at a polarized electron–positron collider

“…This approach can include models mentioned above, for some of which form factors have been calculated in the past [42,43,44,45,46]. B. BSM contribution through effective e + e − hh c interactions This case includes contributions which do not take place through γhh c and Zhh c vertices.…”

Search for the electromagnetic moments of the τ lepton in photon–photon collisions at the LHeC and the FCC-he

“…Also, these couplings at the LHC have examined through the processes [33]. Finally, there is a lot of work related to theã τ anomalous magnetic moment of the τ lepton [34][35][36][37][38][39][40][41][42][43][44]. All of the experimental and theoretical limits on the electric and magnetic dipole moments of the tau lepton are given in Table I. In the investigated processes for examining the electromagnetic dipole moments of the τ lepton in particle accelerators, it is not possible that all the particles are on-shell.…”

“…. Finally, there is a lot of work related to the ãτ anomalous magnetic moment of the τ lepton [34][35][36][37][38][39][40][41][42][43][44]. All of the experimental and theoretical limits on the electric and magnetic dipole moments of the tau lepton are given in Table I.…”