Related papers: Radiative corrections to stoponium annihilation de…
We calculate radiative corrections to decay rates of CP-odd Higgs boson $A$ for various decay modes in the four types of two Higgs doublet models with the softly broken discrete $Z_{2}$ symmetry. The decay branching ratios are evaluated at…
In this paper, we calculate the decay widths and branching fractions for the decays $Z \to H+ \gamma$ up to ${\cal O}(\alpha_{s} v^2)$ accuracy within the framework of nonrelativistic QCD, where $H$ stands for the $S$-wave quarkonium…
We have calculated the next-to-leading order perturbative QCD corrections to the photon energy spectrum in radiative Upsilon decays. The higher-order corrections significantly modify the shape of the spectrum, in particular at large photon…
In this work we study the indirect effects of squarks and gluinos via supersymmetric QCD radiative corrections in the decays of Higgs particles within the Minimal Supersymmetric Standard Model. We consider a heavy supersymmetric spectrum…
We present threshold enhanced QCD corrections to the bottom quark energy distribution in Higgs boson decay and to hadroproduction in $l^+l^-$ annihilation beyond leading order in the strong coupling constant. This is achieved using the…
In some supersymmetric extensions of the Standard Model fairly light superpartner of t-quark is predicted, which may form bound states ({\it stoponiums}) under certain conditions. We study prospects of search for stoponium at the future…
We present a computation of QCD next-to-leading order corrections to the top production and decay process at linear colliders. The top quarks are allowed to be off-shell and the production and decay subprocesses are treated together, thus…
The one-loop supersymmetric QCD quantum effects on the width of the unconventional top quark decay mode $t\rightarrow H^{+}\, b$ are evaluated within the MSSM. The study of this process is useful to hint at the supersymmetric nature of the…
The mass spectra and electromagnetic decay rates of charmonium, bottomonium and B_c mesons are comprehensively investigated in the relativistic quark model. The presence of only heavy quarks allows the expansion in powers of their…
We review the status of radiative corrections to the decay rates of the Standard-Model Higgs boson in the mass range accessible at LEP~2. Specifically, we consider corrections of ${\cal O}(\alpha)$, ${\cal O}(\alpha_sG_Fm_t^2)$, and ${\cal…
A Higgs boson in the intermediate mass range is considered. An effective Lagrangian approach is used in order to evaluate the top-induced QCD corrections of order $\alpha_s^3$ to the decay into light quarks and $O(\alpha_s^4)$ corrections…
Motivated by the restoration of $SU(2)\times U(1)$ at high energy, we suggest that certain ratios of diboson differential cross sections can be used as high-precision observables at the LHC. We rewrite leading-order diboson partonic cross…
Stoponium, a bound state of top squark and its antiparticle in a supersymmetric model, may be found in the ongoing Higgs searches at the LHC. Its WW and ZZ detection ratios relative to the Standard Model Higgs boson can be more than unity…
It is shown that up to an over all scale the lowest-order QCD corrections to $t\to H^+b$ and to $t\to W^+b$ are the same in the heavy top limit. Asymptotically, they are given by $-{4\alpha_s\over 3\pi}[{\pi^2\over 3}-{5\over 4}]$,…
Positronium is an ideal system for the research of the bound state QED. New precise measurement of orthopositronium decay rate has been performed with an accuracy of 150 ppm, and the result combined with the last three is 7.0401 +- 0.0007…
The decay of a light Higgs boson to bottom quarks is dominant and can be exploited for the discovery of the Higgs particle and the measurement of its properties at the LHC and future collider experiments. We perform a first computation of…
The decay widths of top quark to S-wave $b\bar{c}$ and $b\bar{b}$ bound states are evaluated at the next-to-leading(NLO) accuracy in strong interaction. Numerical calculation shows that the NLO corrections to these processes are remarkable.…
In this paper we use the conformal anomaly in QCD to derive the coupling of light radion to gluons in the Randall-Sundrum model and use it to compute the radion production cross section at hadron colliders by gluon fusion. We find that the…
The photonic and QCD radiative corrections at next-to-leading order are calculated for fermion-pair production at muon colliders, maintaining the full mass dependence and helicity information of the muons and the produced fermions.…
In the Minimal Supersymmetric Standard Model, neutralinos lighter than 50 GeV are compatible with all accelerator, precision, and cosmological bounds. Such neutralinos might constitute a relevant decay channel for the Higgs boson, modifying…