Related papers: $Zb\bar{b}$ Loop Correction with Charge 2/3 Single…
We consider Quantum Chromodynamics with external vector, axial-vector, scalar and pseudo-scalar currents and compute three-loop corrections to the corresponding vertex function taking into account massive quarks. We consider all non-singlet…
We present an improved direct measurement of the parity-violation parameter A_b in the Z boson-b quark coupling using a self-calibrating track-charge technique applied to a sample enriched in Z -> b b-bar events via the topological…
We survey the implications for new physics of the discrepancy between the LEP measurement of $R_b$ and its Standard Model prediction. Two broad classes of models are considered: ($i$) those in which new $Z\bbar b$ couplings arise at tree…
The one-loop correction and two-loop contribution to black-body radiation (BBR) shift are restudied. The S-matrix approach and nonrelativistic quantum electrodynamics (NRQED) are adopted in finite temperature case. The relativistic…
Radiative corrections to the parity-violating asymmetry measured in elastic electron-proton scattering are analyzed in the framework of the Standard Model. We include the complete set of one-loop contributions to one quark current…
The Minimal supersymmetric extension of the Standard Model (MSSM) with light stops, charginos or pseudoscalar Higgs bosons has been suggested as an explanation of the too high value of the branching ratio of the Z0 boson into b quarks (Rb…
We calculate the QCD corrections to the cross section of e^+ e^- -> t anti-b H^- and its charge-conjugate counterpart within the minimal supersymmetric extension of the Standard Model. This process is particularly important if m_t < m_H +…
Exploiting the manipulation of the SLC electron-beam polarization, we present precise direct measurements of the parity violation parameters A_c and A_b in the Z boson - c quark and Z boson - b quark coupling. Quark/antiquark discrimination…
I point out that $B \to X_q \l^+ \l^-$ decays $(q = s, d)$ are sensitive probes of possible violation of CKM unitarity. I compute the decay rates and asymmetries in a minimal extension of the Standard Model containing an additional…
We explore corrections to electroweak parameters in the context of Extended Technicolor (ETC) models in which the ETC gauge-boson which generates the top-quark mass carries weak $SU(2)$ charge. For $m_t \sim 150$ GeV there exist potentially…
In this paper we compute one-loop corrections to masses and couplings in the minimal supersymmetric standard model. We present explicit formulae for the complete corrections and a set of compact approximations which hold over the unified…
In the supersymmetric extension of the Standard Model we derive the two-loop QCD corrections to the scalar quark contributions to the electroweak precision observables entering via the rho parameter. A very compact expression is derived for…
We present general formulas for the oblique-correction parameters $S$, $T$, $U$, $V$, $W$, and $X$ in a model of New Physics having arbitrary numbers of scalar leptoquarks of the five permissible types. We allow for a general mixing among…
We calculate isotope mass shift for several light ions using Dirac wave functions and mass shift operator with relativistic corrections of the order of $(\alpha Z)^2$. Calculated relativistic corrections to the specific mass shift vary from…
We consider the leading one-loop Yukawa-coupling corrections to the h^0 b b-bar coupling at O(m_t^2)in the MSSM in the decoupling limit. The decoupling behavior of the corrections from the various MSSM sectors is analyzed in the case of…
We deal with extensions of the Standard Model by adding horizontal interactions between particle generations. We calculate two loop corrections caused by the presence of coupling between hypothetical horizontal gauge bosons and matter…
We review the one-loop corrections to the partial decay width of sbottom-quark into a top quark and a chargino for the parameter space relevant to the TESLA e+e- linear collider. We present the results available in the literature for the…
We compute the weak lensing convergence power spectrum, $C^{\kappa\kappa}(\theta)$, in a dust-filled universe using fully non-linear general relativistic simulations. The spectrum is then compared to more standard, approximate calculations…
We emphasise that even in the extreme chiral limit where only the top and bottom quarks acquire mass, quark mixing is physically meaningful. This implies that the natural value of $|V_{13}|^2 + |V_{23}|^2$ is of order one, which is to be…
We analyze LEP and SLC data from the 1995 Summer Conferences as well as from low energy neutral current experiments for signals of new physics. The reasons for doing this are twofold, first to explain the deviations from the standard model…