اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدProbing New Physics with b to s l l and b to s nu nu transitions
209
0
0.0
(
0
)
تأليف
Michael Wick
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
The rare decay B to K* (to K pi) mu+ mu- is regarded as one of the crucial channels for B physics since its angular distribution gives access to many observables that offer new important tests of the Standard Model and its extensions. We point out a number of correlations among various observables which will allow a clear distinction between different New Physics (NP) scenarios. Furthermore, we discuss the decay B to K* nu anti-nu which allows for a transparent study of Z penguin effects in NP frameworks in the absence of dipole operator contributions and Higgs penguin contributions. We study all possible observables in B to K* nu anti-nu and the related b to s transitions B to K nu anti-nu and B to X_s nu anti-nu in the context of the SM and various NP models.
قيم البحث
اقرأ أيضاً
B --> rho l nu decay is analyzed in the effective theory of heavy quark with infinite mass limit. The matrix element relevant to the heavy to light vector meson semileptonic decays is parametrized by a set of four heavy flavor-spin independent univer
sal wave functions at the leading order of effective theory. The form factors are calculated at the leading 1/m_Q order using the light cone sum rule method in the framework of effective theory. |V_{ub}| is then extracted via B --> rho l nu decay mode.
We study the impact of next-to-next-to-leading order (NNLO) QCD corrections on partial decay rates in B --> X_u l nu decays, at leading-order in the 1/m_b expansion for shape-function kinematics. These corrections are implemented within a modified fo
rm of the BLNP framework, which allows for arbitrary variations of the jet scale mu_i sim 1.5 GeV. Our analysis includes a detailed comparison between resummed and fixed-order perturbation theory, and between the complete NNLO results and those obtained in the large-$beta_0$ approximation. For the default choice mu_i=1.5 GeV used in current extractions of |V_ub| within the BLNP framework, the NNLO corrections induce significant downward shifts in the central values of partial decay rates with cuts on the hadronic variable P_+, the hadronic invariant mass, and the lepton energy. At the same time, perturbative uncertainties are reduced, especially those at the jet scale, which are the dominant ones at next-to-leading order (NLO). For higher values of mu_i and in fixed-order perturbation theory, the shifts between NLO and NNLO are more moderate. We combine our new results with known power-suppressed terms in order to illustrate the implications of our analysis on the determination of |V_ub| from inclusive decays.
The calculation of partial decay rates in B --> X_u l nu decays at next-to-next-to-leading order (NNLO) in alpha_s and to leading order in 1/m_b is described. New results for the hard function are combined with known results for the jet function and
shape-function moments in a numerical analysis which explores the impact of the NNLO corrections on partial decay rates and the determination of |V_{ub}|.
In the heavy quark effective field theory of QCD, we analyze the order 1/m_Q contributions to heavy to light vector decays. Light cone sum rule method is applied with including the effects of 1/m_Q order corrections. We then extract |V_{ub}| from B -> rho l nu decay up to order of 1/m_Q corrections.
The inclusive decay B --> X_u l nu is of much interest because of its potential to constrain the CKM element |V_ub|. Experimental cuts required to suppress charm background restrict measurements of this decay to the shape-function region, where the h
adronic final state carries a large energy but only a moderate invariant mass. In this kinematic region, the differential decay distributions satisfy a factorization formula of the form $H cdot J otimes S$, where S is the non-perturbative shape function, and the object $H cdot J$ is a perturbatively calculable hard-scattering kernel. In this paper we present the calculation of the hard function H at next-to-next-to-leading order (NNLO) in perturbation theory. Combined with the known NNLO result for the jet function J, this completes the perturbative part of the NNLO calculation for this process.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
