Related papers: Limits on a Strong Electroweak Sector from e^+ e^-…
We calculate the event rates for the Standard Model production of two photons plus missing mass through the process electron positron to gamma gamma nu nubar, where nu is any of the three neutrino flavors, at LEP energies. This process can…
Accepting that there is a mass gap above the electroweak scale, the Electroweak Effective Theory (EWET) is an appropriate tool to describe this situation. Since the EWET couplings contain information on the unknown high-energy dynamics, we…
The vanishing of the cross section for particular points in phase space - radiation zeros - is examined for the process $ q \bar q \to W^+W^- \gamma$ at high energy. Unlike the process $q \bar q' \to W^\pm \gamma$, actual zeros only occur…
For successful electroweak baryogenesis to take place through the sphaleron process the universe needs to undergo a strong first order cosmological phase transition. While it does not occur in the Standard Model it becomes possible in the…
We discuss the collider signatures of electroweak (1,0)-mode excitations in the framework of two universal extra dimension (2UED) at the LHC and ILC. In general, pair production of electroweak (1,0)-mode particles of 2UED gives rise to…
Absorption of high-energy $\bar{\nu}_e$ over electrons above the W boson production threshold is reexamined. It is pointed out that, in the case of photon emissions along the direction of incident high-energy $\bar{\nu}_e$, the…
In $e^+ e^-$ collisions, electromagnetic effects caused by large charge density bunches modify the effective acceptance of the luminometer system of the experiments. These effects consequently bias the luminosity measurement from the rate…
For the first time the experiments ALEPH, DELPHI, L3 and OPAL have presented preliminary results for fermion-pair and photon-pair production in e+e- collisions on the full LEP2 data set. The details of the experimental measurements and…
These are the notes of a set of four lectures which I gave at the 2012 CERN Summer School of Particle Physics. They cover the basic ideas of gauge symmetries and the phenomenon of spontaneous symmetry breaking which are used in the…
The double-radiative process e+e- -> Z gamma gamma -> q q~ gamma gamma, where the two hard photons escape detection at low polar angles into opposite directions, is studied in 0.62/fb of data collected with the L3 detector at LEP at…
We study the phenomenology of gauge singlet extensions of the Standard Model scalar sector and their implications for the electroweak phase transition. We determine the conditions on the scalar potential parameters that lead to a strong…
We investigate the reaction e^+ e^- \to W^+ W^-, W^- \to l^- \bar{nu} in a strong coupling scenario as implemented in the BESS model. Energy and angle spectra of the secondary lepton are calculated and compared with the predictions of the…
We systematically analyze the anomalous dipole $\Delta k_{\gamma}$ and quadrupole $\Delta Q_{\gamma}$ moments of the W gauge bosons in the context of the minimal supersymmetric standard model as functions of the soft SUSY breaking…
We investigate the two-photon corrections to the process $p\bar{p} \to e^+e^-$ at large momentum transfer, aimed to access the time-like nucleon form factors. We estimate the two-photon corrections using a hard rescattering mechanism, which…
We study CPT-odd non-minimal Lorentz-symmetry violating couplings in the electroweak sector modifying the interactions between leptons, gauge mediators and the Higgs boson. The tree-level (differential) cross sections for three important…
The reconstruction of fundamental parameters in supersymmetric theories requires the evolution to high scales, where the characteristic regularities in mechanisms of supersymmetry breaking become manifest. We have studied a set of…
We study the pair-production and decay of right handed selectrons within a Gauge Mediated Supersymmetry Breaking Model in polarised $e^-e^-$ interaction. Detailed analyses of the possible signals and backgrounds are performed for a few…
We review models of electroweak symmetry breaking due to new strong interactions at the TeV energy scale and discuss the prospects for their experimental tests. We emphasize the direct observation of the new interactions through high-energy…
Possibility of electroweak baryogenesis (EWBG) via multi-step phase transition (PT) is considered. We investigate the EWBG between $SU(2)$ broken phases in the second step PT of the two-step PT. The produced baryon number asymmetry is…
The mechanism of electroweak symmetry breaking in Little Higgs Models is analyzed in an effective field theory approach. This enables us to identify observable effects irrespective of the specific structure and content of the heavy degrees…