Related papers: Bileptons - Present Constraints and Future Prospec…
We investigate the potential collider signatures of singly-charged and doubly-charged Higgs bosons such as those arising in minimal left-right symmetric models. Focusing on multileptonic probes in the context of the high-luminosity run of…
We investigate the impact of extra leptons on observed tensions in the muon $g-2$ and the first-row CKM unitarity. By introducing a new SU(2)$_L$ doublet lepton and a SU(2)$_L$ triplet lepton, we find that both of the tensions can be…
We show that new physics explanations of the muon $g-2$ anomaly by the contributions of new leptons mediated by the standard model Higgs boson necessarily lead to large rates for $\mu^+ \mu^- \to hh$ and $\mu^+ \mu^- \to hhh$ irrespectively…
We study the sensitivity to doubly charged Higgs bosons, $\Delta^{--}$, in the process $e^-\gamma\to e^+ \mu^-\mu^-$ for centre of mass energies appropriate to future high energy $e^+e^-$ collider proposals. For $M_\Delta <…
The weak dipole moments of leptons and quarks, \ie those related to their $Z$--coupling, are reviewed. Standard Model predictions and experimental results may result in a stringent test for both their pointlike structure and also for the…
I briefly review the Higgs sector in the Standard Model. After summarizing the properties of the Higgs boson, I will discuss the prospects for discovering this particle at the present colliders LEP2 and Tevatron and at the next generation…
The parity solution to the strong CP problem necessarily extends the Standard Model to include the SU$(2)_{\rm R}$ gauge sector and imposes restrictions on the structure of the Yukawa interactions. In this framework, one can consider an…
Supersymmetric theories with significant lepton flavor violation have $\tilde{e}$ and $\tilde{\mu}$ nearly degenerate. In this case, pair production of $\tilde{e}^+ \tilde{e}^-$ and $\tilde{\mu}^+ \tilde{\mu}^-$ at LEPII and at the Next…
We discuss the predictions of the bilepton model which is an extension of the standard model in which the group $SU(2) \times U(1)$ is changed to $SU(3)\times U(1)$ and the fermion families are treated non-sequentially with the third…
Dileptons represent a unique probe for nuclear matter under extreme conditions reached in heavy-ion collisions. They allow to study meson properties, like mass and decay width, at various density and temperature regimes. Present days models…
If new sequential leptons $E^\pm$ and $N^0$ exist, the LEP bound implies $m_E$, $m_N > M_Z/2$. The heaviness of the neutral lepton breaks away from the pattern of the first three generations. The minimal model is to have 4 left-handed…
We study the phenomenology of the type-II seesaw model at a linear e^-e^- collider. We show that the process e^-e^- \rightarrow alpha^-beta^- (alpha, beta = e, mu, tau being charged leptons) mediated by a doubly charged scalar is very…
Motivated by the interest in lepton number violating processes, we study the connection between the rate of Z -> mu e decay and those of the low-energy processes mu ->3 e, and mu -> e conversion in nuclear field. We show that if the vector…
Events with two or more leptons (electrons or muons) with high transverse momentum are measured in electron-proton collisions at HERA using the data sample collected in the period 1994-2005. Multi-lepton events at high transverse momenta…
The possibility of single and pair excited neutrino production in high energy e+e-, gamma-e and gamma-gamma collisions on linear colliders is studied. The integrated cross sections of these subproceses are calculated. Special attention is…
Processes $\tau\rightarrow l\gamma$, $\tau\rightarrow lll$ with $l= e,\mu$ and $\mu(\tau) \to e (\mu) \gamma$ are evaluated in the framework of a model based on the extended symmetry gauge $SU(3)_c \otimes SU(3)_L \otimes U(1)_Y$ with a…
The $SU(3)_C X SU(3)_L X U(1)_X$ gauge model with the minimal scalar sector (two Higgs triplets) is studied in detail. One of the vacuum expectation values $u$ is a source of lepton-number violations and a reason for the mixing among the…
Two-boson momentum correlations at fixed particle number constraint are studied in a simple analytically solvable model of a thermal expanding system. We show that the increase of expansion rate, as well as increase of particle…
In this paper we examine the constraints dedicated LHC multi lepton searches can place on $Z'$ bosons coming from gauged muon number minus tau number, $L_{\mu}-L_{\tau}$. As the $L_{\mu}-L_{\tau}$ gauge boson does not couple to proton…
The energy spectrum of the lepton(s) in e^+e^- --> tt-bar --> l^{+-} ...../l^+l^-..... at next linear colliders (NLC) is studied for arbitrary longitudinal beam polarizations as a possible test of new physics in top-quark couplings. The…