Related papers: Two-loop QCD corrections to $\eta_b \to J/\psi + \…
In this work, we study the radiative decay of $Z$ boson to a $P$-wave quarkonium $H$ in association with a photon, where $H$ can be $\chi_{QJ}$, $h_Q$ with $Q=c,b$ and $J=0,1,2$. The helicity amplitudes and the unpolarized decay widths are…
Higher-order QED radiative corrections to muon decay spectrum are evaluated within the QED structure function approach in the next-to-leading order logarithmic approximation. New analytical results are given in the…
The next to leading order (NLO) QCD corrections to J/psi polarization of hadronproduction at Tevatron and LHC are calculated. The results show that the J/psi polarization is extremely changed from more transversal polarization at leading…
In this work, we study the exclusive decay of $\Upsilon$ into $J/\psi$ in association with $\eta_c$ ($\chi_{c0,1,2}$). The decay widths for different helicity configurations are evaluated up to QCD next-to-leading order within the…
Motivated by very recent measurement of the radiative decays of $\Upsilon(1S)$ to $\chi_{c1}$ at Belle, we use the nonrelativistic QCD factorization theory and calculate the branching fractions of the radiative decays of bottomonium into…
In this work, we investigate the next-to-leading order (NLO) QCD correction to $J/\psi$ associated production with a bottom quark pair from the Higgs boson decay within the nonrelativistic QCD framework. From numerical results, {we find…
The decay $B \to X_s \gamma$ is studied at the Next to Leading Order in QCD in a class of models containing at least two Higgs doublets and with only one charged Higgs boson non-decoupled at low-energy. The two-loop matching condition is…
Cross sections of the heavy quarkonium production process $e^+e^-\to H + \gamma$ at the c.m. energy of $Z^0$-boson resonance are calculated at leading order in $\alpha_s$ with relativistic corrections resummed within the framework of…
The inclusive $J/\psi$ production in $e^+ e^- \to J/\psi c\bar c$ at B factories is one of the most challenging open problems in heavy quarkonium physics. The observed cross section of this double charm production process is larger than…
In this paper the complete two-loop corrections to the Higgs-boson decay, H -> gamma gamma, are presented. The evaluations of both QCD and electroweak corrections are based on a numerical approach. The results cover all kinematical regions,…
By employing the perturbative QCD (PQCD) factorization approach, we studied the sixteen $B/B_s \to \eta_c (\pi, K, \eta^{(\prime)},\rho,K^*,\omega,\phi)$ decays with the inclusion of the currently known next-to-leading order (NLO)…
Next-to-leading order QCD corrections to the QCD-induced $pp \rightarrow l^+l^- \gamma j j +X$ and $pp \rightarrow \bar{\nu}_l \nu_l \gamma jj+X$ processes are presented. The latter is used to find an optimal cut to reduce the contribution…
D0 and CDF collaborations at the Fermilab Tevatron have searched for non-standard-model single top-quark production and set upper limits on the anomalous top quark flavor-changing neutral current (FCNC) couplings $\kappa^g_{tc}/\Lambda$ and…
We study the spectra of the bottomonium and B_c states within perturbative QCD up to order alpha_s^4. The O(Lambda_QCD) renormalon cancellation between the static potential and the pole mass is performed in the epsilon-expansion scheme. We…
We compute next-to-next-to-leading order corrections to the decay width difference of mass eigenstates and the charge-parity (CP) asymmetry $a_{\rm fs}$ in flavour-specific decays of neutral $B$ mesons. We include both current-current and…
We report a calculation of approximate next-to-next-to-leading-order (N$^2$LO) and next-to-N$^2$LO (N$^3$LO) QCD corrections to associated $tW$ production at the LHC, which constitute the dominant contributions to full perturbative…
I present estimates of the branching fractions in the non-leptonic charmonium two-body decay rates for $B^0\rightarrow \psi(2S)\pi^0$ decay and the same decays of $B^+\rightarrow \psi(2S)\pi^+$, $B^0\rightarrow \psi(2S)K^0$ and…
It is interesting to investigate the OZI-forbidden radiative orthoquarkonium decays $J/\psi\to \gamma\pi^0, \gamma\eta$ and $\gamma\eta'$ in perturbative QCD. In this work without the approximations adopted in literature we carry out a full…
We calculate the next-to-leading corrections to the branching ratio of exclusive $B\to K^* \gamma$ decay. The renormalization scale dependence is reduced compared to the leading logarithmic result but there remains a dependence on a cutoff…
We study the radiative leptonic $B_c\to \gamma\ell\bar\nu$ decays in the nonrelativistic QCD effective field theory, and consider a fast-moving photon. As a result the interactions with the heavy quarks can be integrated out, and thus we…