相关论文: Tau $g-2$ at $e^-e^+$ colliders with momentum depe…
If physics beyond the Standard Model (BSM) explains the $4.2\sigma$ difference between the Standard-Model and measured muon anomalous magnetic moment, $a_{\mu}$, minimal flavor violation predicts a shift in the analog quantity for the…
In this paper, we consider phenomenology of a model with an $L_\mu-L_\tau$ gauge symmetry. Since the muon couples to the $L_\mu-L_\tau$ gauge boson (called $Z''$ boson), its contribution to the muon anomalous magnetic moment (muon g-2) can…
The BaBar Collaboration has an intensive program of studying hadronic cross sections at low-energy $e^+e^-$ collisions, accessible via initial-state radiation. Our measurements allow significant improvements in the precision of the…
About 3 sigma deviation from the standard model prediction of muon anomalous magnetic moment (muon g-2) has been reported. We consider new physics beyond the standard model which has new Yukawa interactions with muon. We compute new…
The discrepancy between the muon $g-2$ measurement and the Standard Model prediction points to new physics around or below the weak scale. It is tantalizing to consider the loop effects of a heavy axion (in the general sense, also known as…
This article reviews and updates the Standard Model prediction of the tau lepton g-2. Updated QED and electroweak contributions are presented, together with new values of the leading-order hadronic term, based on the recent low energy e+ e-…
We review the present status of the theoretical evaluation of the anomalous magnetic moment of the the muon within the Standard Model. We mainly focus on the hadronic contributions in the muon g-2 due to vacuum polarization effects,…
We study muon pair production $ e^+ e^- \to \mu^+ \mu^-$ in the noncommutative(NC) extension of the standard model using the Seiberg-Witten maps of this to the second order of the noncommutative parameter $\Theta_{\mu \nu}$. Using…
The long-standing muon g-2 anomaly can be explained by heavy new physics particles through chirally enhanced contributions. It has been recently proposed that a muon collider running at center-of-mass energies of several TeV could test…
The anomalous magnetic ($\tilde{a}_\tau$) and electric dipole ($\tilde{d}_\tau$) moment of tau lepton described in $\tau\bar{\tau}\gamma$ vertices are studied via $\mu^{+}\mu^{-} \rightarrow \tau^+\bar{\tau}^-$ process at the Muon colliders…
A Two-Higgs doublet model (2HDM) can predict the observed muon $g-2$ for an appropriately light pseudoscalar that now faces tight constraints. However, It was shown in past that augmenting the 2HDM by an additional inert doublet can lead to…
We discuss the Type-X (lepton-specific) two Higgs doublet model as a solution of the anomaly of the muon $g-2$. We consider various experimental constraints on the parameter space such as direct searches for extra Higgs bosons at the LEP II…
Using the effective Lagrangian formalism, the anomalous magnetic and electric dipole moments of the tau-lepton in the $\mu^{+}\mu^{-} \rightarrow \mu^{+}\gamma^{*} \gamma^{*} \mu^{-}\rightarrow \mu^{+}\tau \bar{\tau}\mu^{-}$ process at the…
The new measurement of the muon's anomalous magnetic moment released by the Muon g-2 experiment at Fermilab sets strong constraints on the properties of many new particles. Using an effective field theory approach to the interactions of…
Two next generation muon $g-2$ experiments at Fermilab in the US and at J-PARC in Japan have been designed to reach a four times better precision from 0.54 ppm to 0.14 ppm and the challenge for the theory side is to keep up in precision as…
The anomalous magnetic moment of the tau lepton $a_\tau = (g_\tau -2)/2$ strikingly evades measurement, but is highly sensitive to new physics such as compositeness or supersymmetry. We propose using ultraperipheral heavy ion collisions at…
A review of the theoretical and experimental values for the charged lepton (electron and muon) anomalous magnetic moment $a_l= (g_l-2)/2$ is presented. Employing the most accurate value for the fine structure constant $\alpha^{-1}=…
The BABAR collaboration has nearly completed a program of precise measurements of the cross sections for the dominant channels of e+e- --> hadrons from threshold to an energy of 3-5 GeV using the initial-state radiation (ISR) method, i.e.…
The calculation of the hadronic light-by-light scattering contribution to the muon g-2 currently relies entirely on models. Measurements of the form factors which describe the interactions of hadrons with photons can help to constrain the…
The longstanding muon g-2 anomaly may indicate the existence of new particles that couple to muons, which could either be light (< GeV) and weakly coupled, or heavy (>> 100 GeV) with large couplings. If light new states are responsible,…