Related papers: $R$--Parity Violating SUSY or Leptoquarks: Virtual…
We study the production of scalar and vector leptoquarks in $e^-e^-$ scattering. We use the most general couplings to the known fermions which are dimensionless, baryon and lepton number conserving, and $SU(3)_c \otimes SU(2)_L \otimes…
Question of the proper incorporation of spin effects in tau lepton decays is often of importance. In present work, case of the Z/gamma to tau+ tau- production mechanism is studied in detail. As an example, the effects due to the spin…
The Higgs boson production p p (p\bar p) -> b h +X via b g -> b h at the LHC, which may be an important channel for testing the bottom quark Yukawa coupling, is subject to large supersymmetric quantum corrections. In this work the one-loop…
We study the effects of O(alpha_s) supersymmetric QCD (SQCD) corrections on the total production rate and kinematic distributions of polarized and unpolarized top-pair production in pp and p anti-p collisions. At the Fermilab Tevatron p…
The complex Clebsch-Gordon coefficients in the double tetrahedral group T' offers the possibility that CP violation can be entirely geometrical in origin, as pointed out by us recently. In this note, we investigate leptogenesis in a SUSY…
We evaluate the observability of the effects of a scalar singlet leptoquark (LQ) in $\mu$ and $\tau$-pair productions at the $Z$ factory. In the scenario addressing the charged-current anomalies, the LQ contributions to $\mu$-pair final…
One of the most important mechanisms at the Large Hadron Collider (LHC) for the production of the pseudoscalar Higgs boson of the Minimal Supersymmetric Standard Model (MSSM) is the loop-induced gluon fusion process $gg\to A$. The…
A search for pair produced scalar fermions with couplings that violate R-parity has been performed using a data sample corresponding to an integrated luminosity of 56 pb-1 at a centre-of-mass energy of sqrt{s}= 183 GeV collected with the…
CP-violating contributions to Higgs--fermion couplings are absent in the standard model of particle physics (SM), but are motivated by models of electroweak baryogenesis. Here, we employ the framework of the SM effective theory (SMEFT) to…
The possibility of discovering heavy Majorana neutrinos and lepton number violation via the like sign dilepton signal at hadron super- colliders is investigated. The cross-sections for the production of these neutrinos singly as well as in…
Type-II seesaw is a simple scenario in which Majorana neutrino masses are generated by the exchange of a heavy scalar electroweak triplet. When endowed with additional heavy fields, such as right-handed neutrinos or extra triplets, it also…
The purely leptonic decays D -> e nu and Ds -> e nu, for which no experimental limits exist, are highly suppressed in the Standard Model. Mere observation of these decays at the B factories BELLE/BaBar or forthcoming CLEO-c would be a clear…
We present a comprehensive analysis of low-energy signals of hypothetical scalar leptoquark interactions in lepton and kaon transitions. We derive the most general effective four-fermion Lagrangian induced by tree-level scalar leptoquark…
We analyze the recent experimental evidence for an excess of $\tau$-lepton production in several exclusive semileptonic $B$-meson decays in the context of two-Higgs-doublet models. These decay modes are sensitive to the exchange of charged…
We extend the $SU(3)_C \times SU(3)_L \times U(1)_X$ model with neutral leptons (331LHN) by introducing scalar leptoquarks. We determine the particle content of the leptoquark multiplets and their Yukawa interactions with fermions. We find…
Quark-sector Lorentz violation is studied in the context of Drell-Yan dilepton production including effects from Z-boson exchange. We show the chiral nature of the weak interactions enables parity-violating and spin-dependent effects to be…
The so-called supersymmetric flavour and CP problems are deeply related to the origin of flavour and hence to the origin of the SM Yukawa couplings themselves. We show that realistic SU(3) flavour symmetries with spontaneous CP violation…
We analyze the next-to-leading order SUSY-QCD corrections to the production of Higgs particles at hadron colliders in supersymmetric extensions of the Standard Model. Besides the standard QCD corrections due to gluon exchange and emission,…
In the minimal supersymmetric standard model with R-parity violation, the lepton number violating top quark interactions can contribute to the top pair production at a linear collider via tree-level u-channel squark exchange diagrams. We…
A search for squarks in R-parity violating supersymmetry is performed in e^+- p collisions at HERA using the H1 detector. The full data sample taken at a centre-of-mass energy sqrt{s}=319 GeV is used for the analysis, corresponding to an…