Related papers: Heavy-to-light decays with a two-loop accuracy
Masses of heavy Standard Model fermions (top-quark, bottom-quark, and tau-lepton) play an important role in the analysis of theories beyond the SM. They serve as low-energy input and reduce the parameter space of such theories. In this…
We present our recent calculation of the third order corrections to the semileptonic $b \to c$ and the muon decays. The calculation has been performed in an expansion around the limit $m_c \sim m_b$, but shows decent convergence even for…
The semileptonic $B_s (B) \to K_2^*(a_2, f_2) \ell\nu$, $\ell=\tau, \mu$ transitions are investigated in the frame work of the three-point QCD sum rules. Considering the quark condensate contributions, the relevant form factors of these…
We compute $\mathcal O(\alpha^2 Z)$ radiative corrections to superallowed $\beta$ decays with a heavy-particle effective field theory that systematically describes the interactions of low-energy ultrasoft photons with nuclei. We calculate…
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…
The successful operation of LHC provides a great opportunity to study the processes where heavy baryons are involved. {In this work we mainly study} the weak transitions of $\Sigma_b\to \Sigma_c$. Assuming the reasonable quark-diquark…
We consider the $\Lambda N\to NN$ weak transition, responsible for a large fraction of the non-mesonic weak decay of hypernuclei. We follow on the previously derived effective field theory and compute the next-to-leading one-loop…
Within the HQET, the heavy to light vector meson transitions are systematically analyzed to the order of 1/m_Q. Besides the four universal functions at the leading order, there are twenty-two independent universal form factors at the order…
We calculate the part of the order $\alpha_s^2$ correction to the semileptonic heavy quark decay rate proportional to the number of light quark flavors, and use our result to set the scale for evaluating the strong coupling in the order…
Three-loop corrections to hyperfine splitting in muonium generated by the gauge invariant sets of diagrams with muon and tauon loop light-by-light scattering blocks are calculated. These results complete calculations of all light-by-light…
Analytic formulae are given for QCD corrections to the lepton spectra in decays of polarised up and down type heavy quarks. These formulae are much simpler than the published ones for the corrections to the spectra of charged leptons…
I consider a model for heavy meson decays based on an effective quark-meson Lagrangian. The model is constrained by the known symmetries of QCD in the m_Q -> infinity limit for the heavy quarks, and chiral symmetry in the light quark…
We study the heavy flavor conserved semi-leptonic decay $B_s\to B\ell\nu$ in the covariant light front approach. The covariant light front quark model is used to calculate the transition form factors of $B_s\to B^{(*)}$ as well as $D_s\to…
The tree level semileptonic $\Lambda_{b}\to pl\nu$ and $\Lambda_{c}\to nl\nu$ transitions are investigated using the light cone QCD sum rules approach in full theory. The spin--1/2, $\Lambda_{Q}$ baryon with $Q=b$ or $c$, is considered by…
A review is given on the quantum correction $\Delta r$ in the $W$--$Z$ mass correlation at the electroweak two-loop level, as derived from the calculation of the muon lifetime in the Standard Model. Exact results for $\Delta r$ and the…
We have calculated the rate of the decay b -> clv to second order in alpha_s in the limit that the b and c quarks have equal masses. The results here confirm recent calculations done in the opposite limit where the c-quark is much lighter…
The current status of lattice calculation of weak matrix elements for heavy quark systems is reviewed. After an assessment of systematic errors in present simulations, results for the B meson decay constant, the B-parameter B_B and…
We employ a Dyson-Schwinger equation model to effect a unified and uniformly accurate description of light- and heavy-meson observables, which we characterise by heavy-meson leptonic decays, semileptonic heavy-to-heavy and heavy-to-light…
By means of a heavy-top-quark effective Lagrangian, we calculate the three-loop corrections of O(alpha_s^2 G_F M_t^2) to the H->bb-bar partial decay width of the standard-model Higgs boson with intermediate mass M_H<<2M_t. We take advantage…
$s\to u$ weak decays of heavy flavor hadrons play a unique role in the field of heavy flavor physics. In this work, we investigate semileptonic $s\to u$ decays of singly heavy baryons in the light-front approach under the three-quark…