New Physics in b Decays

10.1142/12696 ◽  
2022 ◽  
Author(s):  
Sheldon Stone ◽  
Marina Artuso ◽  
Gino Isidori
Keyword(s):  
2019 ◽  
Vol 222 ◽  
pp. 01007 ◽  
Author(s):  
Dmitri Melikhov

Rare B-decays induced by flavour-changing neutral currents (FCNC) is one of the promising candidates for probing physics beyond the Standard model. However, for identifying potential new physics from the data, reliable control over QCD contributions is necessary. We focus on one of such QCD contributions – the charming loops – that potentially can lead to difficulties in disentangling new physics effects from the observable and discuss the possibility to gain control over theoretical predictions for charming loops.


2019 ◽  
Vol 34 (06n07) ◽  
pp. 1950036 ◽  
Author(s):  
Saeed Kamali

In this work, we study the effects of New Physics (NP) operators on the inclusive [Formula: see text] decay including power [Formula: see text] corrections in the NP operators. In analogy with [Formula: see text] observables, we study the observable [Formula: see text]. We present some numerical results for [Formula: see text] and compare the results for this observable with and without power corrections in the NP contributions.


2000 ◽  
Vol 15 (08) ◽  
pp. 1079-1156
Author(s):  
I. I. BIGI

The narrative of these lectures contains three main threads: (i) CP violation despite having so far been observed only in the decays of neutral kaons has been recognized as a phenomenon of truly fundamental importance. The KM ansatz constitutes the minimal implementation of CP violation: without requiring unknown degrees of freedom it can reproduce the known CP phenomenology in a nontrivial way. (ii) The physics of beauty hadrons — in particular their weak decays — opens a novel window onto fundamental dynamics: they usher in a new quark family (presumably the last one); they allow us to determine fundamental quantities of the Standard Model like the b quark mass and the CKM parameters V(cb), V(ub), V(ts) and V(td); they exhibit speedy or even rapid [Formula: see text] oscillations. (iii) Heavy Quark Expansions allow us to treat B decays with an accuracy that would not have been thought possible a mere decade ago. These three threads are joined together in the following manner: (a) Huge CP asymmetries are predicted in B decays, which represents a decisive test of the KM paradigm for CP violation. (b) Some of these predictions are made with high parametric reliability, which (c) can be translated into numerical precision through the judicious employment of novel theoretical technologies. (d) Beauty decays thus provide us with a rich and promising field to search for New Physics and even study some of its salient features. At the end of it there might quite possibly be a New Paradigm for High Energy Physics. There will be some other threads woven into this tapestry: electric dipole moments, and CP violation in other strange and in charm decays.


2000 ◽  
Vol 476 (3-4) ◽  
pp. 233-242 ◽  
Author(s):  
G. Abbiendi ◽  
K. Ackerstaff ◽  
P.F. Akesson ◽  
G. Alexander ◽  
J. Allison ◽  
...  
Keyword(s):  
B Decays ◽  

2006 ◽  
Vol 21 (08n09) ◽  
pp. 1724-1737 ◽  
Author(s):  
ULRICH NIERSTE

I summarize the theoretical progress in the determination of the CKM elements since Lepton-Photon 2003 and present the status of the elements and parameters of the Cabibbo-Kobayashi-Maskawa (CKM) matrix. One finds |Vus| = 0.2227 ± 0.0017 from K and τ decays and |Vcb| = (41.6 ± 0.5) · 10-3 from inclusive semileptonic B decays. The unitarity triangle can now be determined from tree-level quantities alone and the result agrees well with the global fit including flavour-changing neutral current (FCNC) processes, which are sensitive to new physics. From the global fit one finds the three CKM angles θ12 = 12.9° ± 0.1°, θ23 = 2.38° ± 0.03° and θ13 = 0.223° ± 0.007° in the standard PDG convention. The CP phase equals [Formula: see text] at 1σ CL and [Formula: see text] at 2σ CL. A major progress are first results from fully unquenched lattice QCD computations for the hadronic quantities entering the UT fit. I further present the calculation of three-loop QCD corrections to the charm contribution in [Formula: see text] decays, which removes the last relevant theoretical uncertainty from the [Formula: see text] system. Finally I discuss mixing-induced CP asymmetries in [Formula: see text] penguin decays, whose naive average is below its Standard Model value by 3σ.


2021 ◽  
Vol 81 (6) ◽  
Author(s):  
S. Biswas ◽  
P. Nayek ◽  
P. Maji ◽  
S. Sahoo

AbstractMotivated by the recent LHCb results of lepton flavour violation on $$b\rightarrow s$$ b → s and $$b\rightarrow c$$ b → c transitions we study the lepton flavour violating (LFV) baryonic decays $${\Lambda }_{b}\rightarrow {\Lambda }l_{i}^{+}l_{j}^{-}$$ Λ b → Λ l i + l j - in non-universal $$Z^{\prime }$$ Z ′ model. We discuss the two-fold decay distribution of $${\Lambda }_{b}\rightarrow {\Lambda }l_{i}^{+}l_{j}^{-}$$ Λ b → Λ l i + l j - decays in terms of transversity amplitudes. From this distribution we study the differential branching ratio and lepton side forward-backward asymmetry in new physics (NP). The predicted values of the observables are very interesting and that might emboss the footprints of NP more aesthetically.


2002 ◽  
Author(s):  
Chao-Shang Huang ◽  
Wei LIAO
Keyword(s):  

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