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Related papers: Effects of mixing with quark singlets

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We investigate the consequences of deviations from the Standard Model observed in $b\to s\mu\mu$ transitions for flavour-changing neutral-current processes involving down-type quarks and neutrinos. We derive the relevant Wilson coefficients…

High Energy Physics - Phenomenology · Physics 2020-09-16 Sébastien Descotes-Genon , Svjetlana Fajfer , Jernej F. Kamenik , Martín Novoa-Brunet

We show that the study of CP asymmetries in neutral B-meson decays provides a very sensitive probe of flavour-changing neutral currents (FCNC). We introduce two new angles, $\alpha_{SM}$ and $\beta_{SM}$, whose main feature is that they can…

High Energy Physics - Phenomenology · Physics 2010-11-23 G. Barenboim , F. J. Botella , G. C. Branco , O. Vives

We present a general phenomenological analysis of a class of Two Higgs Doublet Models with Flavor Changing Neutral Currents arising at the tree level. The existing constraints mainly affect the couplings of the first two generations of…

High Energy Physics - Phenomenology · Physics 2007-05-23 David Atwood , Laura Reina , Amarjit Soni

We study the potential effect of anomalous couplings of the third generation quarks to gauge bosons in rare B decays. We focus on the constraints from flavor changing neutral current processes such as $b\to s\gamma$ and $b\to s…

High Energy Physics - Phenomenology · Physics 2009-10-31 Gustavo Burdman , M. C. Gonzalez-Garcia , S. F. Novaes

Motivated by recent preliminary results from the SLD Collaboration on the measurement of angle-dependent B-Bbar energy correlations in Z^0 -> b bbar events, we propose a class of observables that can be computed as a power expansion in the…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. Brandenburg , P. Nason , C. Oleari

A review is given of latest results on tests of the flavour independence of strong interactions. Heavy quark mass effects are evident in the data and are now taken into account at next-to-leading order in QCD perturbation theory. The…

High Energy Physics - Experiment · Physics 2007-05-23 P. N. Burrows

We discuss new physics (NP) contributions to kaon mixing parameter $\varepsilon_K$, direct CP violation parameter $\varepsilon^\prime/\varepsilon$ of $K\to \pi\pi$, and rare decays $K^+\to \pi^+\nu\bar\nu$, $K_L\to \pi^0\nu\bar\nu$ and…

High Energy Physics - Phenomenology · Physics 2023-03-22 Girish Kumar

We study flavour-changing neutral current decays of the top quark in the democratic Three Higgs Doublet Model featuring a $Z_3$-symmetric scalar potential and Natural Flavour Conservation. In this framework, while such processes are absent…

High Energy Physics - Phenomenology · Physics 2026-01-26 Baradhwaj Coleppa , Benjamin Fuks , Akshat Khanna

These lectures review some of the progress made in the quantitative understanding of B decays. The emphasis here is on applications of QCD using perturbative and non-perturbative techniques. In some cases, however, phenomenological models…

High Energy Physics - Phenomenology · Physics 2011-04-15 A. Ali

At long-baseline neutrino experiments, neutral-current (NC) events accumulate in large numbers but are seldom exploited for new physics searches. We demonstrate their potential using non-standard neutrino interactions (NSI) with quarks as a…

High Energy Physics - Phenomenology · Physics 2026-04-20 Julia Gehrlein , Jaime Hoefken Zink , Pedro A. N. Machado , João Paulo Pinheiro

Large neutrino event numbers in future experiments measuring coherent elastic neutrino nucleus scattering allow precision measurements of standard and new physics. We analyze the current and prospective limits of a light scalar particle…

High Energy Physics - Phenomenology · Physics 2018-06-13 Yasaman Farzan , Manfred Lindner , Werner Rodejohann , Xun-Jie Xu

We revisit the impact of top partial compositeness on electroweak precision observables in the misaligned vacuum basis. We identify a new source for $S$ in the singlet mixing case, and for $S$-$T$ in the bi-doublet mixing, stemming from…

High Energy Physics - Phenomenology · Physics 2022-12-21 Haiying Cai , Giacomo Cacciapaglia

Collisions of particles at the energy frontier can reveal new particles and forces via localized excesses. However, the initial observation may be consistent with a large variety of theoretical models, especially in sectors with new top…

High Energy Physics - Phenomenology · Physics 2025-02-21 Krish Wu , Brandon Sun , Nitish Polishetty , Justin Kline , Max Fieg , Daniel Whiteson

The mixing of neutral mesons is sensitive to some of the highest scales probed in laboratory experiments. In light of the planned LHCb Upgrade II, a possible upgrade of Belle II, and the broad interest in flavor physics in the tera-$Z$…

High Energy Physics - Phenomenology · Physics 2020-10-07 J. Charles , S. Descotes-Genon , Z. Ligeti , S. Monteil , M. Papucci , K. Trabelsi , L. Vale Silva

These proceedings review the status of New Physics contributions to flavour violating $B$ decays. The anomalies in charged and neutral current $B$ decays related to lepton flavour universality violation have received a substantial amount of…

High Energy Physics - Phenomenology · Physics 2022-09-21 Monika Blanke

In a global analysis of the latest parity-violating electron scattering measurements on nuclear targets, we demonstrate a significant improvement in the experimental knowledge of the weak neutral-current lepton-quark interactions at low…

High Energy Physics - Phenomenology · Physics 2008-11-26 R. D. Young , R. D. Carlini , A. W. Thomas , J. Roche

An interesting mass relation between down type quarks and charged leptons has been recently predicted within a supersymmetric SU(3)_c \times SU(2)_L \times U(1)_Y model based on the A4 flavor symmetry. Here we propose a simple extension…

High Energy Physics - Phenomenology · Physics 2013-08-02 S. Morisi , M. Nebot , Ketan M. Patel , E. Peinado , J. W. F. Valle

In the heavy-quark and large-energy limits, symmetry relations reduce the number of independent form factors governing heavy-to-light $B$-meson decays. Exploiting these relations, the form factors can be parametrized while systematically…

High Energy Physics - Phenomenology · Physics 2026-05-11 Saba Ayub , Saba Shafaq , Arslan Sikandar , M. Jamil Aslam

The study of the processes with the production of top quarks represents a unique possibility to test the standard model (SM) predictions and probe the new physics effects. Potential deviations from the SM expectations are parametrized…

High Energy Physics - Experiment · Physics 2020-08-17 Kirill Skovpen

A study of the top quark interactions via flavour-changing neutral current (FCNC) processes provides an intriguing connection between the heaviest elementary particle of the standard model (SM) of particle physics and the new scalar bosons…

High Energy Physics - Experiment · Physics 2022-11-23 Nuno Castro , Kirill Skovpen