Probe of the electromagnetic moments of the tau lepton in gamma-gamma collisions at the CLIC

Abstract

We have investigated the electromagnetic moments of the tau lepton in e + e − → e + γ * γ * e − → e + ττ e − process at the CLIC. We have obtained 95% confidence level bounds on the anomalous magnetic and electric dipole moments for various values of the integrated luminosity and the center of mass energy. We have shown that the e + e − → e + γ * γ * e − → e + ττ e − process at the CLIC leads to a remarkable improvement in the existing experimental bounds on the anomalous magnetic and electric dipole moments.

Improved sensitivity on the electromagnetic dipole moments of the top quark in γγ , γγ* , and γ*Billur1, Köksal2, Gutiérrez‐Rodríguez3 2017Phys. Rev. DSelf Cite230190View full textAdd to dashboardCite

“…In this work, we have taken into account the maximum virtuality of the photon is Q 2 max = 2 GeV 2 . The larger values of Q 2 max do not make a significant contribution to the sensitivity limits which is similar to results in previous works [69][70][71][72]. The minimum value of the Q 2 min is given by…”

H →τ + τ − γ as a probe of the τ magnetic dipole moment

“…Another interesting direction for the future would be to study the prospects at a future e + e − collider such as the ILC or a future circular collider [59,60]. While the rate for hZ production at such colliders is considerably smaller than the inclusive Higgs production at the LHC, new physics saturating the LEP bound nonetheless allows for a handful of events, and the prospects depend sensitively on the ability to efficiently reconstruct the signal events and reject backgrounds.…”

Model-independent sensitivity estimates for the electromagnetic dipole moments of the τ -lepton at the CLIC

“…We take advantage of our previous works on the collision modes γγ, γγ Ã , and γ Ã γ Ã [26,[56][57][58] to calculate the total cross section for the γγ → τ þ τ − and γγ → τ þ τ − γ reactions. The corresponding Feynman diagrams for these processes are given in Figs.…”

“…(12). In addition, we take into account the systematic uncertainties for the collider and use the usual formula for the χ 2 function [24][25][26]66],…”

“…Furthermore, there has been extensive theoretical work done in BSM models that contributes to dipole moments of charged leptons: CP-violation BSM [14], extra dimensions [15], seesaw model [16], version III of the two-higgs-doublet model [17], noncommutative geometry [18], nonuniversal extra dimensions [19], left-right symmetric model [20], E 6 superstring models [21], simplest little Higgs model [22], and 331 model [23]. There are also bounds independent of the model such as γp collisions [24], e − γ scattering [25], and γγ collisions [26,27]. Other limits on the MM and EDM of the τ-lepton are reported in Refs.…”