Related papers: Constraint on parity-violating muonic forces
We propose a set of precision muon-related observables that serve as a tool to constrain new physics models. Using LEP's precision measurements on the $Z$-boson pole, we derive bounds on the new physics quantum contributions to the decay $Z…
The "proton size puzzle" and the "muon anomalous moment problem" are incomplete descriptions of significant discrepancies of Standard Model calculations with experiments. What is particularly new is that the experiments and theory confront…
A measurement of the Lamb shift in muonic hydrogen yields a charge radius of the proton that is smaller than the CODATA value by about 5 standard deviations. We explore the possibility that new scalar, pseudoscalar, vector, and tensor…
The leptonic bound states positronium and muonium are used to constrain galileon contributions to the Lamb shift of muonic hydrogen. Through the application of a variety of bounds on lepton compositeness, it is shown that either the…
New results from the CDF Collaboration on the invariant mass distribution of dijet events observed at the Tevatron are used to constrain the masses and couplings of new gauge bosons ($W'$ and $Z'$) as well as fundamental diquarks which can…
We discuss the collider phenomenology of TeV Z' gauge bosons related to the absence of a bare mu-term in the superpotential. Decays of the type Z' --> Higgsinos can directly test whether a gauge symmetry is responsible for forbidding the…
We study some of the consequences of the SU(6)$_{L}\otimes$U(1)$_{Y}$ model of unification of electroweak interactions and families with a horizontal gauge group SU(2)$_{H}$, paying special attention to processes with flavor changing…
We consider a gauged $U(1)_{L_\mu-L_\tau}$ extension of the left-right symmetric theory in order to simultaneously explain neutrino mass, mixing and the muon anomalous magnetic moment. We get sizeable contribution from the interaction of…
We consider the three CP-conserving dimension-6 operators that encode the leading new-physics effects in the triple gauge couplings. The contributions to the standard-model electromagnetic dipole and semi-leptonic vector and axial-vector…
A massive $U(1)^{\prime}$ gauge boson known as a "dark photon" or $A^{\prime}$, has long been proposed as a potential explanation for the discrepancy observed between the experimental measurement and theoretical determination of the…
The QED hadronic vacuum polarization function plays an important role in the determination of precision electroweak observables and of the anomalous magnetic moment of the muon. These contributions have been computed from data, by means of…
We consider the strangeness-changing decays of hyperons into another baryon and missing energy which is carried away by a pair of invisible spinless bosons. Pursuing a model-independent approach and taking into account constraints from the…
We consider tree-level corrections to hypercharge changing semileptonic decays of certain baryons induced by a minimal supersymmetric standard model with explicitly broken R-parity via $L$-violation. This study leads to a new set of…
We constrain, from rare tau decays, several combinations of $\lambda$ and $\lambda'$ type couplings coming from Supersymmetry without R-parity. The processes that we consider are tau --> l M, tau --> l_i l_j l_k, and tau --> l gamma, where…
We show that lepton number violating muon decays, \mu^+ -> e^+ + \nu_e-bar + \nu_i-bar (i=e, \mu or \tau), can consistently explain the neutrino anomaly reported by the LSND experiment. Two effective operators in the Standard Model are…
New physics effects in $B$ decays are routinely modeled through operators invariant under the strong and electromagnetic gauge symmetries. Assuming the scale for new physics is well above the electro-weak scale, we further require…
The V-A structure of the weak interactions leads to definite amplitude hierarchies in exclusive heavy-to-light decays mediated by $b \to (d,s)\gamma$ and $b \to (d,s) \ell \bar{\ell}$. However, the extraction of right-handed currents beyond…
We present a new way to break parity symmetry in left-right symmetric models using boundary conditions on the fields residing in the fifth dimension. We also discuss the connection between the limits on the size of extra dimensions and the…
A non-universal interaction, which involves only the third family leptons induces lepton flavor violating couplings and contributes to the anomalous magnetic moment of muon. In this paper, we study the effects of non-universal interaction…
We investigate the potential of rare hyperon decays to probe the short distance structure in the $s\to d\nu\bar\nu$ and $s\to d\ell^+\ell^-$ transitions. Hyperon decays into neutrinos ($B_1\to B_2\nu\bar\nu$) can be reliably predicted by…