相关论文: Two-loop heavy top effects on the MZ-MW interdepen…
Results are presented for the leading two-loop contributions of O(alpha_t alpha_s) to the masses and mixing effects in the Higgs sector of the MSSM with complex parameters. They are obtained in the Feynman-diagrammatic approach using…
We discuss the impact of the two-loop corrections to the Higgs mass in the NMSSM beyond $O(\alpha_S(\alpha_b + \alpha_t))$. For this purpose we use the combination of the public tools SARAH and SPheno to include all contributions stemming…
We improve the determination of the Higgs-boson mass in the MSSM with heavy superpartners, by computing the two-loop threshold corrections to the quartic Higgs coupling that involve both the strong and the electroweak gauge couplings.…
The off-shell two-loop correction to the massive quark propagator in an arbitrary covariant gauge is calculated and results for the bare and renormalized propagator are presented. The calculations were performed by means of a set of new…
The presently most accurate prediction for the W-boson mass in the Standard Model is obtained by combining the complete two-loop result with the known higher-order QCD and electroweak corrections. The numerical impact of the different…
We evaluate O(alpha_b alpha_s) corrections in the Higgs boson sector of the CP-conserving MSSM, generalising the known result in the literature to arbitrary values of tan beta. A detailed analysis of the renormalisation in the bottom/scalar…
The assumption that two-loop top corrections are well approximated by the $O(G_mu^2 mt^4)$ contribution is investigated. It is shown that in the case of the ratio neutral-to-charged current amplitudes at zero momentum transfer the $O(G_mu^2…
We compute the dominant two-loop electroweak correction, of O(G_F M_t^2), to the partial width of the decay of an intermediate-mass Higgs boson into a pair of photons. We use the asymptotic-expansion technique in order to extract the…
The Higgs-mass dependence of the two-loop contributions to muon decay is analyzed at the two-loop level. Exact results are given for the Higgs-dependent two-loop corrections associated with the fermions, i.e. no expansion in the top-quark…
We investigate the effect of one-loop corrections of ${\cal O}(\alpha_S^2\alpha_W)$ on the $t\bar t$ invariant mass spectrum at the Large Hadron Collider (LHC) in presence of both resonant and non-resonant Higgs boson effects. We show that…
We compute analytically the complete electroweak two-loop corrections to the $B^0-{\bar B}^0$ mixing. These corrections fix the normalization of the electroweak coupling employed in the extraction of $|V_{td}|$ and reduce the theoretical…
We compute the pole mass of the gluon in QCD from the local composite operator formalism at two loops in the MSbar renormalization scheme. For Yang-Mills theory an estimate of the mass at two loops is 2.13 Lambda_MSbar.
Recently exact results for the complete fermionic two-loop contributions to the prediction for the W-boson mass from muon decay in the electroweak Standard Model have been published [hep-ph/0007091]. This paper illustrates the techniques…
The evolution of the strong coupling constant $\alpha_s$ from $M_Z$ to the GUT scale is presented, involving three-loop running and two-loop decoupling. Accordingly, the two-loop transition from the $\bar{\rm MS}$ to the $\bar{\rm DR}$…
We analytically calculate the dominant two-loop electroweak correction, of O(G_F^2 m_t^4), to the partial width of the decay of a Higgs boson, with mass M_H << m_t, into a bottom-quark pair, and describe the most important conceptual and…
Motivated by recent preliminary results from the SLD Collaboration on the measurement of angle-dependent B-Bbar energy correlations in Z^0 -> b bbar events, we propose a class of observables that can be computed as a power expansion in the…
The dominant electroweak corrections to the production cross sections and partial decay widths of a light Standard-Model Higgs boson, with mass M_H << 2m_t, are due to top-quark loops. By means of a low-energy theorem, we study at the…
We present O(alpha_s^2) corrections to the decay t-->bW in the limit of a very large top quark mass, m_t >> m_W. We find that the O(alpha_s^2) effects decrease the top quark decay width Gamma_t by about 2%: Gamma_t =…
We complete the effective potential calculation of the two-loop, top/bottom Yukawa corrections to the Higgs boson masses in the Minimal Supersymmetric Standard Model, by computing the O(at^2 + at*ab + ab^2) contributions for arbitrary…
We discuss a recent analysis of a dominant two-loop electroweak correction, of O(G_F M_t^2), to the partial width of the decay of an intermediate-mass Higgs boson into a pair of photons. The asymptotic-expansion technique was used in order…