Bounding the Electromagnetic and Weak Dipole Moments of the Tau–lepton in a Simplest Little Higgs Model

Abstract

From the total cross section for the reaction e + e − → τ + τ − γ at the Z 1 pole and in the framework of a simplest little Higgs model (SLHM), we get a limit on the characteristic energy scale of the model f , f ≥ 5.4 T eV , which in turn induces bounds on the electromagnetic and weak dipole moments of the tau-lepton. Our bounds on the electromagnetic moments are consistent with the bounds obtained by the L3 and OPAL collaborations for the reaction e + e − → τ + τ − γ. We also obtained bounds on the tau weak dipole moments which are consistent with the bounds obtained recently by the DELPHI and ALEPH collaborations from the reaction e + e − → τ + τ − .

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

“…The most restrictive experimental bounds are obtained by BELLE: −2.2 < Re(d τ ) < 4.5 × (10 −17 e cm) and −2.5 < Im(d τ ) < 0.8 × (10 −17 e cm). There are model dependent and independent studies on the anomalous dipole moments of the tau lepton in the literature [19][20][21][22][23][24][25][26][27].…”

Sensitivity on the electromagnetic dipole moments of the tau-lepton at the CLIC

“…The best sensitivities obtained on a τ and d τ are −0.00012 ≤ a τ ≤ 0.00014 and |d τ (ecm)| = 7.445 × 10 −19 [6]. Furthermore, there has been extensive theoretical work done in new physics beyond de Standard Model that contributes to dipole moments of tau-lepton: Left-right symmetric model [17], E 6 superstring models [18], simplest little Higgs model [19], and 331 model [20]. Other limits on the MM and EDM of the τ-lepton are reported in Refs.…”

Dipole moments of the tau-neutrino from the process e+e−→νν¯γ

“…[3,4] this model is that is independent of the mass of the additional Z 2 heavy gauge boson and so we have the characteristic energy scale of the model f as the only additional parameter. The MM, EDM and the characteristic energy scale of the simplest little Higgs model f give a contribution to the total cross section for the process e + e − → ννγ.…”