Related papers: Systematically Testing Singlet Models for $(g-2)_\…
A discrepancy between the measured anomalous magnetic moment of the muon $(g - 2)_{\mu}$ and computed Standard Model value now stands at a combined $4.2\sigma$ following experiments at Brookhaven National Lab (BNL) and the Fermi National…
We study limits from dilepton searches on leptoquark completions to the Standard Model in the parameter space motivated by anomalies in the $b \rightarrow s$ sector. After a full Run-2 analysis by LHCb, the disparity in lepton flavour…
We consider a type I or type X two Higgs doublets model with a modified lepton sector. The generalized lepton sector is also flavor conserving but with the new Yukawa couplings completely decoupled from lepton mass proportionality. The…
A muon collider operating in the TeV energy range can be an ideal s-channel Higgs boson factory. This is especially true for a heavy Higgs boson. The non-perturbative dynamical aspects of such a Higgs boson were recently investigated with…
Supersymmetric particles at the multi-TeV scale will escape direct detection at planned future colliders. However, such particles induce non-decoupling corrections in processes involving the accessible superparticles through violations of…
If the origin of neutrino mass is at the TeV energy scale, collider experiments may in fact {\it map out} all the elements of the $3 \times 3$ neutrino mass matrix, up to an overall scale. Two examples \cite{mrs,ma01} are discussed and one…
Rare kaon decays are excellent probes of light, new weakly-coupled particles. If such particles $X$ couple preferentially to muons, they can be produced in $K\to \mu \nu X$ decays. In this letter we evaluate the future sensitivity for this…
We study the capabilities of a muon collider, at 3 and 10 TeV center-of-mass energy, of probing the interactions of the Higgs boson with the muon. We consider all the possible processes involving the direct production of EW bosons ($W,Z$…
We show that inclusion of a single generation of vector-like leptons in the Two-Higgs Doublet Models significantly enlarges the allowed parameter space consistent with the muon anomalous magnetic moment, as well as with other theoretical…
The electroweak (EW) sector of the Minimal Supersymmetric Standard Model (MSSM), with the lightest neutralino as Dark Matter (DM) candidate, can account for a variety of experimental data. This includes the DM content of the universe, DM…
We discuss the use of massive vectors for the interpretation of some recent experimental anomalies, with special attention to the muon $g-2$. We restrict our discussion to the case where the massive vector is embedded into a spontaneously…
We study the discrimination power of future multi-TeV muon colliders for a large set of models with extended gauge symmetries and additional neutral gauge bosons ("$Z'$-models"). Our study is carried out using a $\chi^2$-analysis of…
We discuss the current status of theoretical and experimental constraints on the real Higgs singlet extension of the Standard Model. For the second neutral (non-standard) Higgs boson we consider the full mass range from 1 GeV to 1 TeV…
We present a search for a new narrow, spin-1, high mass resonance decaying to $\mu^+\mu^- + X $, using a matrix element based likelihood and a simultaneous measurement of the resonance mass and production rate. In data with 4.6 fb$^{-1}$ of…
Rare flavour-changing neutral-current transitions $b \to s \mu^+ \mu^-$ probe higher energy scales than what is directly accessible at the LHC. Therefore, the presence of new physics in such transitions, as suggested by the present-day LHCb…
We study the phenomenology of the charged Higgs boson at future muon colliders. We investigate both the pair production $\mu^+ \mu^- \to H^+ H^-$, the single production $\mu^+ \mu^- \to W^\pm H^\mp$, as well as the Vector Boson Fusion (VBF)…
We propose to generate non-universal gaugino masses in SU(5) GUT with the generalized Planck-scale mediation SUSY breaking mechanism, in which the non-universality arises from proper wavefunction normalization with lowest component VEVs of…
TeV-scale seesaw mechanisms are interesting due to their potential testability at existing collider experiments. Herein we propose an E$_6$-inspired model allowing a TeV-scale pseudo-Dirac singlet neutrino seesaw mechanism with naturally…
The electric and magnetic dipole moments of the electron and of the muon provide stringent tests of the Standard Model and sensitive probes of new physics. By contrast, the corresponding dipole moments of the $\tau$ lepton remain weakly…
Recently, Kajiyama, Okada and Yagyu (KOY) proposed an electron/muon specific two Higgs doublet model. In this model, an S3 symmetry suppresses flavor changing neutral currents instead of a Z2 symmetry. In the "Type I" version of the model,…