Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userInclusive |V_cb| and global fit
171
0
0.0
(
0
)
Authors
C.Schwanda
Ask ChatGPT about the research
No Arabic abstract
A reliable determination of the Cabibbo-Kobayashi-Maskawa matrix element $|V_{cb}|$ is mandatory for precision flavor physics and for the search for CP violating phases from new, heavy particles. In this article, we review the theory of the determination of $|V_{cb}|$ from inclusive semileptonic $B$ decays. We discuss the available measurements of the semileptonic $B$ branching fraction and other inclusive observables in B decays relevant to the determination of $|V_{cb}|$. Finally, we perform a global fit to extract $|V_{cb}|$ and the $b$-quark mass $m_b$.
rate research
Read More
In this article, we review the theory and the experimental status of inclusive semileptonic B meson decays B -> Xc l nu. Based on these inputs, we present the latest determination of the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element |V_cb| and of the b-quark mass m_b, obtained by the Heavy Flavor Averaging Group (HFAG).
We perform global fits to the moments of semileptonic B decay distributions and extract |V_cb|, the heavy quark masses, and the non-perturbative parameters of the heavy quark expansion. We include NNLO perturbative corrections and recent determinations of the charm mass, and discuss how they improve the precision of the global fit. In particular, using the m_c determination of Ref.[11] we get m_b^kin=4.541(23) GeV and |V_cb|=(42.42+- 0.86) 10^{-3}. We also discuss the implications of the new fits for the normalization of rare B decays, the zero-recoil sum rule in B-> D* l nu, and the inclusive determination of |V_ub|.
In this talk, I present the brand new results from the H1 and ZEUS Collaborations on the combination of all previously published inclusive deep inelastic cross sections at HERA for neutral and charged current $e^pm p$ scattering for zero beam polarisation and the corresponding parton distributions functions, HERAPDF 2.0, at up to next-to-next-to-leading order (NNLO). The results also include a new precise determination at next-to-leading order (NLO) of the strong coupling constant $alpha_s(M^2_Z)=0.1184pm 0.0016$ (excluding scale uncertainties) based on a simultaneous fit to the combined inclusive cross section data and jet production data.
The DGLAP analyses of the nuclear parton distribution functions (nPDF) based on the global fits to the data are reviewed, and the results from EKS98 and HKM are compared. The usefulness of measuring hard probes in $pA$ collisions, at the LHC in particular, is demonstrated.
In this presentation Gfitter results from the global Standard Model (SM) fit to electroweak precision data are discussed. We have used the latest measurements of m_top and M_W and the most recent results for direct Higgs searches at LEP and Tevatron. We obtain M_H=121^{+17}_{-6} GeV and a 95% CL upper limit of 155 GeV for the SM Higgs mass. The forth-order result for the strong coupling constant is given by alpha_S(M_Z^2)=0.1193 +- 0.0028(exp) +- 0.0001(theo). In addition the electroweak fit has been performed with the top mass determined from the ttbar cross-section as measured at Tevatron.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
