Related papers: Constraints on Extra Gauge Bosons in e gamma Colli…
The process gamma gamma \to mu tau b bbar is studied in the minimal supersymmetric standard model within a large tan_beta scenario imposing on the parameter space present direct and indirect constraints from B physics and rare LFV…
Contactlike nonstandard effective interactions can be revealed through deviations of observables from the Standard Model predictions. If such deviations were observed, the relevant source should be identified among the possible models that…
We investigate the sensitivity of total cross sections of $e+p \rightarrow W,Z$ to CP-conserving non-standard $WW\gamma$ couplings. We include all the important production mechanisms and study the dependence of the total $W$ cross sections…
The discovery potential and diagnostic abilities of proposed future colliders for new heavy neutral ($Z'$) and charged ($W'$) gauge bosons are summarized. Typical bounds achievable on $M_{Z',W'}$ at the TEVATRON, DI-TEVATRON, LHC, 500 GeV…
We present a search for excited and exotic electrons (e*) decaying to an electron and a photon, both with high transverse momentum. We use 202/pb of data collected in p-pbar collisions at sqrt(s) = 1.96 TeV with the CDF II detector. No…
We report the results of a search for a heavy neutral gauge boson Z' decaying into the dielectron final state using data corresponding to an integrated luminosity of 5.4 fb-1 collected by the D0 experiment at the Fermilab Tevatron Collider.…
Many types of physics beyond the standard model include an extended electroweak gauge group. If these extensions are associated with flavor symmetry breaking, the gauge interactions will not be flavor-universal. In this note we update the…
We present a phenomenological study of neutral gauge bosons and fermions in an extended Standard model with SU(3)C x SU(4)L x U(1)X gauge symmetry.The model includes gauge bosons and fermions without exotic charges and is distinguished by…
A first measurement of the cross section of the process e+e- -> Z gamma gamma is reported using a total integrated luminosity of 231 pb^-1 collected with the L3 detector at centre-of-mass energies of 182.7 GeV and 188.7 GeV. By selecting…
We investigate the status of models containing exotic fermions or extra Z-like neutral gauge bosons in the light of the recent data on anomalous magnetic moment of muon. We find that it is possible to extract interesting bounds on the…
A search for nu_bar_mu to nu_bar_e oscillations has been conducted at the Los Alamos Meson Physics Facility using nu_bar_mu from mu+ decay at rest. The nu_bar_e are detected via the reaction (nu_bar_e,p) -> (e+,n), correlated with the 2.2…
The recently completed calculation of the full electroweak O(alpha) corrections to the charged-current four-fermion production processes e+e- --> nu_tau tau+ mu- anti-nu_mu, u anti-d mu- anti-nu_mu, and u anti-d s anti-c is briefly…
We compare two most relevant loop induced muon number violating processes, \mu --> e \gamma and \mu-e conversion in nuclei, in constraining new physics. Because of much richer structure of the latter process it may be enhanced with respect…
Together with the existence of new neutral gauge bosons, models based on extended gauge groups (rank $> 4$) often predict also new charged fermions. A mixing of the known fermions with new states with {\it exotic} weak-isospin assignments…
We describe a general search for resonances decaying to a neutral e-mu final state in ppbar collisions at a center-of-mass energy of 1.96 TeV. Using a data sample representing 344 pb^-1 of integrated luminosity recorded by the CDF-II…
Littlest Higgs model predicts some extra particles beyond the Standard Model. Among them, an extra neutral gauge boson A_H is lightest and its mass could be a few hundred GeV. We study production and decay of A_H at future e^+ e^- inear…
We obtain bounds on the anomalous magnetic and electric dipole moments of the tau-neutrino through the reaction $e^{+}e^{-}\to \nu \bar \nu \gamma$ at the $Z_1$-pole in the framework of a Left-Right symmetric model and a class of $E_6$…
We examine the sensitivity of the process e+e- -> nu nubar + gamma to additional W-like bosons which arise in various models. The process is found to be sensitive to W' masses up to several TeV.
There is a recent proposal of identifying the Higgs particle of the Standard Model as a pseudo Nambu-Goldstone boson. This new broken symmetry introduces new particles and new interactions. Among these new interactions a central role to get…
An extension of the standard model of electro-weak interactions by an extra abelian gauge boson is given, in which the extra gauge boson and the hypercharge gauge boson both couple to an axionic scalar in a form that leads to a Stueckelberg…