Related papers: $b\to s\gamma$ and $\epsilon_1$ Constraints on Sup…
New limits on the Higgs mass from LEP and new calculations on the radiative (penguin) decay of the b->s gamma branching ratio restrict the parameter space of the Constrained Minimal Supersymmetric Standard Model (CMSSM). We find that for…
A novel technique for measuring the mass of the top quark that uses only the kinematic properties of its charged decay products is presented. Top quark pair events with final states with one or two charged leptons and hadronic jets are…
We explore the possible values of the $\mu \to e \gamma$ branching ratio, $\text{BR}(\mu\rightarrow e\gamma)$, and the electron dipole moment (eEDM), $d_e$, in no-scale SU(5) super-GUT models with the boundary conditions that soft…
In this work, we reinterpret ATLAS and CMS dijet resonance searches to set robust constraints on all hypothetical tree-level scalar and vector mediators with masses up to 5 TeV, assuming a diquark or a quark-antiquark coupling with an…
The rare top quark decays mediated by a new neutral massive gauge boson that is predicted in models with extended gauge symmetries are studied. We focus on the processes $t\to cV, uV$ induced at the one loop level, where $V =\gamma, g$, by…
We determine the top quark mass m_t using t-tbar pairs produced in the D0 detector by \sqrt{s} = 1.8 TeV p-pbar collisions in a 125 pb^-1 exposure at the Fermilab Tevatron. We make a two constraint fit to m_t in t-tbar -> b W^+bbar W^-…
The quark-level process $b \to s \gamma$ has been used extensively to place constraints on new interactions. These same interactions can be further constrained from the enhancement they induce in the quark-level $s \to d \gamma$ transition,…
A search for new dielectron mass resonances using data recorded by the CDF II detector and corresponding to an integrated luminosity of 5.7/fb is presented. No significant excess over the expected standard model prediction is observed. In…
Precise measurements of Z-boson parameters and W-boson and t-quark masses put strong constraints on non SU(2) * U(1) singlet New Physics. We demonstrate that one extra generation passes electroweak constraints even when all new particle…
Within the Minimal Supersymmetric Grand Unified Theory (MSGUT) masses of the predicted supersymmetric particles are constrained by the world averaged values of the electroweak and strong coupling constants, the lower limits on the proton…
We study the constraints on gravity scale $M_P$ in extra-dimension gravitational theory, obtained from gravity-induced processes. The obtained constraints are subdivided into strong (though not robust) and reliable (though less strong). The…
We derive perturbativity constraints on beyond standard model scenarios with extra gauge groups, such as $SU(2)$ or $U(1)$, whose generators contribute to the electric charge, and show that there are both upper and lower limits on the…
The $b\rightarrow s+ \gamma$ decay is a powerful tool for testing models of new physics because the new physics diagrams enter in the same loop order as the Standard Model ones. The current experimental and theoretical status of this decay…
We present a new measurement of the top quark mass in $t\bar t$ events in which both $W$ bosons from top quarks decay into lepton ($e \nu,\mu \nu$). We use events collected by the CDF experiment from $p\bar p$ collisions at \sqrt s=1.8 TeV…
We obtain a new constraint on the CP-violating flavor mixing between the left-handed top scalar quark (\tilde{t}_L) and charm scalar quark (\tilde{c}_L), by considering a chargino loop contribution to chromo-electric dipole moment of…
Possible anomalous couplings of the top-quark to on-shell photons and gluons are constrained by the recent results of the CLEO Collaboration on both inclusive and exclusive radiative $B$ decays. We find that the process \bsg\ can lead to…
The predictions of SU(5) supergravity models with radiative breaking constrained by experimental proton decay bounds are discussed. It is shown that cosmological constraints further restrict the parameter space but can be satisfied for a…
An analysis is made on bottom-tau Yukawa unification in supersymmetric (SUSY) SU(5) grand unified theory (GUT) in the framework of minimal supergravity, in which the parameter space is restricted by some experimental constraints including…
We demonstrate that in a recently proposed unified leptoquark model based on the gauge group $SU(4)_C\times SU(2)_L \times U(1)_R$ significant deviations from the Standard Model values of $R_K$ and $R_{K^*}$ can be accommodated without any…
Randall-Sundrum models are models of quark flavor, because they explain the hierarchies in the quark masses and mixings in terms of order one localization parameters of extra dimensional wavefunctions. The same small numbers which generate…