Related papers: On-shell Renormalization with Vector-like Leptons,…
In the MSSM, the Higgs couplings to down-type quarks and leptons, normalized with respect to their corresponding Standard Model values, coincide at tree-level and this degeneracy is only slightly broken at the quantum level. Motivated by…
We derive new constraints on the quantities delta_{XY}^{ij}, X,Y=L,R, which parametrise the flavour-off-diagonal terms of the charged slepton mass matrix in the MSSM. Considering mass and anomalous magnetic moment of the electron we obtain…
The new experiment data of muon g-2 is reported by the workers at Fermilab National Accelerator Laboratory(FNAL). Combined with the previous Brookhaven National Laboratory(BNL) E821 result, the departure from the standard model prediction…
Within the $\nu$MSSM, a Minimal Supersymmetric neutrino See-saw Model, Lepton Flavour Violating Higgs couplings are strongly enhanced at large $\tan\beta$ ($\gsim30$), which can lead to BR$(H^0/A^0 \to \tau\mu) \simeq O(10^{-4})$, for…
We study a renormalizable theory that includes a heavy weak-singlet vectorlike lepton, $\tau^\prime$, that decays into a pseudoscalar boson and a tau lepton. We show that this can be the dominant decay mode of $\tau^\prime$ provided the…
We use renormalization-group methods in effective field theory to improve the theoretical prediction for the cross section for Higgs-boson production at hadron colliders. In addition to soft-gluon resummation at NNNLL, we also resum…
We calculate radiative corrections to a full set of coupling constants for the 125 GeV Higgs boson at the one-loop level in two Higgs doublet models with four types of Yukawa interaction under the softly-broken discrete $Z_2$ symmetry. The…
A formula is derived that allows the computation of one-loop mass shifts for self-dual semilocal topological solitons. These extended objects, which in three spatial dimensions are called semi-local strings, arise in a generalized Abelian…
We consider the renormalization group improvement in the theory of the Standard Model (SM) Higgs boson playing the role of an inflaton with a strong non-minimal coupling to gravity. At the one-loop level with the running of constants taken…
In a supersymmetric extension of the standard model where baryon and lepton numbers are local gauge symmetries(BLMSSM) and the Yukawa couplings between Higgs doublets and exotic quarks are considered, we study the one loop diagrams and the…
We show that a high-scale leptogenesis can be consistent with a low-scale one-loop neutrino mass generation. Our models are based on the SU(3)_c\times SU(2)_L\times U(1)_Y\times U(1)_{B-L} gauge groups. Except a complex singlet scalar for…
The ongoing searches for Higgs-boson signals in data taken at the CERN LHC and the Fermilab Tevatron crucially rely on the decay channels H -> Z l l and H -> W l nu. We present a precision study of the partial widths of these decay channels…
The anomalous magnetic moment of the muon is one of the most precisely measured quantities in physics. Its experimental value exhibits a $4.2 \, \sigma$ discrepancy $\delta a_\mu=(251 \pm 59) \times 10^{-11}$ with its theoretical value…
We classify all possible one-particle (scalar and fermion) extensions of the Standard Model that can contribute to the anomalous magnetic moment of leptons. We review the cases already discussed in the literature and complete the picture by…
Minimal Composite Higgs Models (MCHM) have long provided a solution to the hierarchy problem of the Standard Model, yet suffer from various sources of fine tuning that are becoming increasingly problematic with the lack of new physics…
Studies of on-shell and off-shell Higgs boson production in the four-lepton final state are presented, using data from the CMS experiment at the LHC that correspond to an integrated luminosity of 80.2 fb$^{-1}$ at a center-of-mass energy of…
Heavy neutral leptons (HNLs) are an attractive minimal extension of the Standard Model, as is a singlet scalar $s$ mixing with the Higgs boson. If both are present, it is natural for HNLs to interact with $s$. For a light singlet,the decay…
A first search is presented for vector-like leptons (VLLs) decaying into a light long-lived pseudoscalar boson and a standard model $\tau$ lepton. The pseudoscalar boson is assumed to have a mass below the $\tau^+\tau^-$ threshold, so that…
The recent observation of the muon $(g-2)_{\mu}$ anomaly continues to challenge the explanations provided by the Standard Model. However, this anomaly can potentially find reconciliation within the framework of two-Higgs doublet models,…
We consider the resonant production of charged sleptons at the LHC via R-parity violation followed by gauge decays to a charged lepton and a neutralino which then decays via R-parity violation. This gives a signature of two like-sign…