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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…

High Energy Physics - Phenomenology · Physics 2009-11-13 Alakabha Datta

Neutral-meson mixing is loop suppressed in the Standard Model, leading to the possibility of enhanced sensitivity to new physics. The uncertainty in Standard Model predictions for $B$-meson oscillation frequencies is dominated by…

High Energy Physics - Lattice · Physics 2015-09-24 C. C. Chang

Decays of $B$ mesons with leptons in the final state offer an interesting laboratory to search for possible effects of physics from beyond the Standard Model. In view of puzzling patterns in experimental data, the violation of lepton…

High Energy Physics - Phenomenology · Physics 2021-08-02 Robert Fleischer , Ruben Jaarsma , Gilberto Tetlalmatzi-Xolocotzi

We revisit the $L_\mu - L_\tau$ extension of the Standard Model that can simultaneously address anomalies in semileptonic $B$ meson decays and the nature of dark matter (DM). In the region favored by the $B$ anomalies, this scenario is…

High Energy Physics - Phenomenology · Physics 2022-09-09 Douglas Tuckler

Lattice matrix elements are briefly reviewed. In the quenched approximation $f_B$, $B_B$ and $B_K$ are now under good control. Experimental hints for $f^{\rm expt}_{D_S}> f^{\rm QQCD}_{D_S}$ are noted; precise determination of $f_{D_S}$…

High Energy Physics - Phenomenology · Physics 2016-11-23 Amarjit Soni

We revisit the possibilities of accommodating the experimental indications of the lepton flavor universality violation in $b$-hadron decays in the minimal scenarios in which the Standard Model is extended by the presence of a single…

High Energy Physics - Phenomenology · Physics 2021-09-22 Andrei Angelescu , Damir Bečirević , Darius A. Faroughy , Florentin Jaffredo , Olcyr Sumensari

We analyze constraints on the anomalous $Wtb$ couplings from $B$-physics experiments, performing a correlated analysis and allowing all anomalous couplings to differ simultaneously from their Standard-Model (SM) values. The $B$-physics…

High Energy Physics - Phenomenology · Physics 2020-09-15 Anastasiia Kozachuk , Dmitri Melikhov

We investigate solutions to the flavour anomalies in $B$ decays based on loop diagrams of a "split" dark sector characterised by the simultaneous presence of heavy particles at the TeV scale and light particles around and below the…

High Energy Physics - Phenomenology · Physics 2020-09-01 Luc Darmé , Marco Fedele , Kamila Kowalska , Enrico Maria Sessolo

In order to simultaneously account for both $R_{D^{(\ast)}}$ and $R_{K^{(\ast)}}$ anomalies in $B$-decays, we consider an extension of the Standard Model by a single vector leptoquark field, and study how one can achieve the required lepton…

High Energy Physics - Phenomenology · Physics 2020-01-29 C. Hati , J. Kriewald , J. Orloff , A. M. Teixeira

We investigate the constraints on the flavour violating parameters from the decay B --> X_s gamma, taking into account the interplay of the various sources of flavour violation in the unconstrained MSSM. We present a systematic leading…

High Energy Physics - Phenomenology · Physics 2011-01-05 Thomas Besmer , Christoph Greub , Tobias Hurth

The Standard Model with a light Higgs provides a very accurate description of the electroweak precision observables. The largest deviation between the Standard Model predictions and the experimental measurements, the forward-backward…

High Energy Physics - Phenomenology · Physics 2011-05-10 Leandro Da Rold

The updated analysis of the LHCb Collaboration on the lepton flavor violation suggests that the new physics should couple to muons and electrons with comparable magnitudes, resulting in the anomalies in both rare decay channels, $b…

High Energy Physics - Phenomenology · Physics 2023-11-13 Sang Quang Dinh , Hieu Minh Tran

We observe that quantities like (f_{B_s}/f_B) / (f_{D_s} /f_D) are predicted to be unity both by heavy quark and by light quark flavor symmetries. Hence, the deviation from the symmetry prediction must be simultaneously small in both…

High Energy Physics - Phenomenology · Physics 2010-11-01 Benjamin Grinstein

The most common predictions for rare $K$ and $B$ decay branching ratios in the Standard Model are based on the CKM elements $|V_{cb}|$ and $|V_{ub}|$ resulting from global fits, that are in the ballpark of their inclusive and exclusive…

High Energy Physics - Phenomenology · Physics 2022-08-10 Andrzej J. Buras , Elena Venturini

There exist experimental hints from the B sector for CP violation beyond the Standard Model (SM) CKM paradigm. An anomalous dimuon asymmetry was reported by the D0 collaboration, while tension exists between $B \to \tau \nu$ and $S_{\psi…

High Energy Physics - Phenomenology · Physics 2011-09-08 Sean Tulin , Peter Winslow

If electroweak symmetry breaking arises via strong dynamics, electroweak precision tests and flavour physics experiments suggest that the minimal model should closely resemble the Standard Model at the LHC. I describe two directions going…

High Energy Physics - Phenomenology · Physics 2010-05-07 Ben Gripaios

The recent observation of the mass difference in $B_s$ system seems to be not in complete agreement with the corresponding standard model value. We consider the model with an extra vector like down quark to explain this discrepancy and…

High Energy Physics - Phenomenology · Physics 2008-12-18 R. Mohanta , A. K. Giri

We examine current collider constraints on some simple $Z^\prime$ models that fit neutral current $B-$anomalies, including constraints coming from measurements of Standard Model (SM) signatures at the LHC. The `MDM' simplified model is not…

High Energy Physics - Phenomenology · Physics 2020-01-29 B. C. Allanach , J. M. Butterworth , Tyler Corbett

Leptoquark models are prime candidates for new physics (NP) explanations of the long-standing anomalies in semi-leptonic $B$ decays; $b\to c \tau \bar\nu$ (encoded in $R(D^{(\ast)})$) and $b\to s\ell\bar\ell (\ell=e,\mu)$ transitions.…

High Energy Physics - Phenomenology · Physics 2025-11-24 Andreas Crivellin , Syuhei Iguro , Teppei Kitahara

We employ a bottom-up and model-independent technique to search for non-Abelian discrete flavour symmetries capable of predicting viable CKM and PMNS matrices alongside of special patterns of leptoquark couplings. In particular, we analyze…

High Energy Physics - Phenomenology · Physics 2020-02-19 Jordan Bernigaud , Ivo de Medeiros Varzielas , Jim Talbert