scholarly journals RECENT BABAR RESULTS ON B DECAYS

2008 ◽  
Vol 23 (21) ◽  
pp. 3218-3223
Author(s):  
◽  
P. J. CLARK

Several recent key results from the BABAR experiment are presented, most using 383.6 fb−1 of data. In particular, the search for B+ → τ+ν, inclusive and exclusive measurements of |Vub|, measurements of b → dγ decays and new observations of rare charmless hadronic decays. The new results provide important experimental constraints on the Standard Model and new physics models.

2013 ◽  
Vol 22 (03) ◽  
pp. 1330006 ◽  
Author(s):  
Z. J. AJALTOUNI ◽  
E. DI SALVO

This review paper stresses the possible connection between time-reversal violation and new physics processes beyond the standard model. In particular, this violation is proposed as an alternative to CP violation in the search for such unkown processes. Emphasis is put on the weak decays of heavy hadrons, especially beauty ones. Specific methods for extracting useful parameters from experimental data are elaborated in order to test TR symmetry. These methods could be used successfully in the analysis of the LHC data.


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.


2007 ◽  
Vol 22 (30) ◽  
pp. 5433-5442
Author(s):  
R. J. BARLOW

New results on rare decays of B mesons and τ leptons are summarised. Measurement are generally in excellent agreement with the Standard Model predictions, the only exceptions being the polarisation of vector particles in B decays and the non-appearance of CP violation in B ± → K ±π0.


2006 ◽  
Vol 21 (14) ◽  
pp. 1137-1150 ◽  
Author(s):  
CHUAN-HUNG CHEN ◽  
CHAO-QIANG GENG

We study the decays of B→K(*)ℓ+ℓ- in split supersymmetry with R-parity violation. We find that the decay branching ratio of B→Kτ+τ- in the new physics model due to the scalar interactions can be 1.8×10-6 which is about one order of magnitude larger than in the standard model, whereas those of B→Kℓ+ℓ- (ℓ=e and μ) and the K* modes are insensitive to the new physics. On the other hand, the forward–backward asymmetries of B→Kτ+τ- and Kμ+μ-, vanishing in the standard model, can be over 10 and 1%, respectively. In addition, we show that the new interactions will significantly change the forward–backward asymmetry in B→K*τ+τ-.


2020 ◽  
Vol 234 ◽  
pp. 01004 ◽  
Author(s):  
P. de Simone

Tests of lepton flavour universality in B decays offer an excellent opportunity to test the Standard Model, and show hints of new physics in analyses performed by the LHCb, Belle and BaBar experiments. Several theoretical models proposed to explain possible violation of lepton flavour universality claim a connection with lepton flavour violation in B decays. These proceedings review the experimental status of the tests of lepton flavour universality and the searches of lepton flavour violation in B decays.


2002 ◽  
Vol 17 (22) ◽  
pp. 2936-2950 ◽  
Author(s):  
MATTHIAS NEUBERT

Recent developments in the theory of CP violation in the B-meson system are reviewed, with focus on the determination of sin 2β from B → J/ψ K decays, its implications for tests of the Standard Model and searches for New Physics, and the determination of γ and α from charmless hadronic B decays.


2021 ◽  
Vol 81 (10) ◽  
Author(s):  
Wolfgang Altmannshofer ◽  
Peter Stangl

AbstractThe anomalies in rare B decays endure. We present results of an updated global analysis that takes into account the latest experimental input – in particular the recent results on $$R_K$$ R K and BR$$(B_s \rightarrow \mu ^+\mu ^-)$$ ( B s → μ + μ - ) – and that qualitatively improves the treatment of theory uncertainties. Fit results are presented for the Wilson coefficients of four-fermion contact interactions. We find that muon specific Wilson coefficients $$C_9 \simeq -0.73$$ C 9 ≃ - 0.73 or $$C_9 = -C_{10} \simeq -0.39$$ C 9 = - C 10 ≃ - 0.39 continue to give an excellent description of the data. If only theoretically clean observables are considered, muon specific $$C_{10} \simeq 0.60$$ C 10 ≃ 0.60 or $$C_9=-C_{10} \simeq -0.35$$ C 9 = - C 10 ≃ - 0.35 improve over the Standard Model by $$\sqrt{\Delta \chi ^2} \simeq 4.7\sigma $$ Δ χ 2 ≃ 4.7 σ and $$\sqrt{\Delta \chi ^2} \simeq 4.6\sigma $$ Δ χ 2 ≃ 4.6 σ , respectively. In various new physics scenarios we provide predictions for lepton flavor universality observables and CP asymmetries that can be tested with more data. We update our previous combination of ATLAS, CMS, and LHCb data on BR$$(B_s \rightarrow \mu ^+\mu ^-)$$ ( B s → μ + μ - ) and BR$$(B^0\rightarrow \mu ^+\mu ^-)$$ ( B 0 → μ + μ - ) taking into account the full two-dimensional non-Gaussian experimental likelihoods.


2019 ◽  
Author(s):  
Sean Benson

In the Standard Model, the three charged leptons are identical copies of each other, apart from mass differences. Experimental tests of this feature in semileptonic decays of -hadrons are highly sensitive to New Physics particles which preferentially couple to the 2nd and 3rd generations of leptons. A review of the latest lepton universality tests in semileptonic transitions at is reported.


2007 ◽  
Vol 85 (6) ◽  
pp. 607-612
Author(s):  
A Datta

Rare decays of the B meson are sensitive to new physics effects. Several experimental results on these decays have been difficult to understand within the Standard Model (SM) though more precise measurements and a better understanding of SM theory predictions are needed before any firm conclusions can be drawn. In this note we try to understand the present data assuming the presence of new physics. We find that the data points to new physics of an extended Higgs sector and we present a two-Higgs-doublet model with a 2–3 flavor symmetry in the down-type quark sector that can explain the deviations from the Standard Model reported in several rare B decays. PACS Nos.: 11.30.Er, 11.30.Hv, and 13.20.He


2004 ◽  
Vol 19 (31) ◽  
pp. 5463-5475 ◽  
Author(s):  
DAVID LONDON

I review CP violation in the standard model (SM). I also describe the predictions for CP violation in the B system, along with signals for physics beyond the SM. I stress the numerous contributions of Pat O'Donnell to this subject. Finally, I discuss a new method for measuring new-physics parameters in B decays. This knowledge will allow us to partially identify any new physics which is found, before its direct production at high-energy colliders.


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