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Related papers: Addendum to: Combined Constraints on First Generat…

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We use the current CMS and ATLAS data for the leptonic $pp \to WW, WZ$ channels to show that diboson production is, for a broad class of flavour models, already competitive with LEP-1 measurements for setting bounds on the dimension six…

High Energy Physics - Phenomenology · Physics 2019-03-27 Christophe Grojean , Marc Montull , Marc Riembau

The "Cabibbo Angle Anomaly" (CAA) originates from the disagreement between the CKM elements $V_{ud}$ and $V_{us}$ extracted from superallowed beta and kaon decays, respectively, once compared via CKM unitarity. It points towards new physics…

High Energy Physics - Phenomenology · Physics 2021-02-19 Andreas Crivellin , Fiona Kirk , Claudio Andrea Manzari , Marc Montull

New neutral heavy gauge bosons ($Z^\prime$) are predicted within many extensions of the Standard Model. While in case they couple to quarks the LHC bounds are very stringent, leptophilic $Z^\prime$ bosons (even with sizable couplings) can…

High Energy Physics - Phenomenology · Physics 2021-06-30 Andrzej J. Buras , Andreas Crivellin , Fiona Kirk , Claudio Andrea Manzari , Marc Montull

We investigate the impact of flavour-conserving, non-universal quark-lepton contact interactions on the dilepton invariant mass distribution in $p~p \to \ell^+ \ell^-$ processes at the LHC. After recasting the recent ATLAS search performed…

High Energy Physics - Phenomenology · Physics 2017-09-13 Admir Greljo , David Marzocca

We study effects of beyond the Standard Model physics coupling third generation quarks to leptons of the first two generations. We parametrize these effects by dimension-six effective operators, and we also consider related simplified UV…

High Energy Physics - Phenomenology · Physics 2020-08-26 Daniel Stolarski , Alberto Tonero

Lepton flavor violation (LFV) within the realm of the Standard Model is forbidden. However recent neutrino experiments strongly suggest neutrino oscillations, giving way to LFV. Beyond SM theories, such as supersymmetry and supergravity…

High Energy Physics - Experiment · Physics 2007-05-23 N. G. Unel

Some anomalies in the processes $b\to s\ell\ell$ ($\ell=\mu,e$) and $b\to c \ell\bar\nu_\ell$ ($\ell=\tau,\mu,e$), in particular in the observables $R_K$ and $R_{D^{(\ast)}}$, have been found by the BaBar, LHCb and Belle Collaborations,…

High Energy Physics - Phenomenology · Physics 2017-09-13 Eugenio Megias , Mariano Quiros , Lindber Salas

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

The most efficient way to extend the Standard Model of particle theory so that it accommodates the observed B anomalies is the hypothesis of a leptoquark which is a color-triplet weak-singlet boson with electric charge $Q=+\frac{2}{3}$. We…

High Energy Physics - Phenomenology · Physics 2022-07-12 Claudio Corianò , Paul H. Frampton

LHCb found hints for physics beyond the standard model in $B\to K^*\mu^+\mu^-$, $B\to K^*\mu^+\mu^-/B\to K^*e^+e^-$ and $B_s\to\phi\mu^+\mu^-$. In addition, the BABAR results for $B\to D^{(*)}\tau\nu$ and the CMS excess in…

High Energy Physics - Phenomenology · Physics 2016-04-20 Andreas Crivellin

We point out that in extended supersymmetric models such as supersymmetric left-right models, it is possible to have leptoquarks that explain the HERA high $Q^2$ anomaly without giving up R-parity conservation. The leptoquarks belong to…

High Energy Physics - Phenomenology · Physics 2009-10-30 B. Dutta , R. N. Mohapatra , S. Nandi

We have investigated a flavour model [1] which inspired by small squared-mass difference measured in solar neutrino oscillation experiments and observability in neutrinoless double beta decay experiments. In our model, the $1^{\rm st.}$ and…

High Energy Physics - Phenomenology · Physics 2017-08-23 Hiroyuki Ishida

We analyze lepton flavour violating transitions, leptonic magnetic dipole moments (MDMs) and electric dipole moments (EDMs) in a class of models characterized by the flavour symmetry A4 x Z3 x U(1)_{FN}, whose choice is motivated by the…

High Energy Physics - Phenomenology · Physics 2008-12-18 Ferruccio Feruglio , Claudia Hagedorn , Yin Lin , Luca Merlo

After a summary of the motivations for searching flavour violating decays and electric dipole moments in the leptonic sector, I briefly sketch the present status of the limits on lepton-slepton misalignement and discuss the potentialities…

High Energy Physics - Phenomenology · Physics 2007-05-23 Isabella Masina

A search for second and third generation scalar and vector leptoquarks produced in ep collisions via the lepton flavour violating processes ep -> mu X and ep -> tau X is performed by the H1 experiment at HERA. The full H1 ep data sample…

High Energy Physics - Experiment · Physics 2011-08-05 David M. South

We study $b \to s \ell_1^+ \ell_2^-$ transitions, both for the lepton flavour conserving $\ell_1=\ell_2$ and violating case $\ell_1 \neq \ell_2$, in a minimal extension of the Standard Model proposed in [1]. In this framework, the Standard…

High Energy Physics - Phenomenology · Physics 2026-01-23 Pietro Colangelo , Fulvia De Fazio , Davide Milillo

While the $S_3$ scalar leptoquark presents a possible tree-level explanation of the $b \to s \ell \ell$ flavour anomalies, it suffers from two conceptual problems which are often disregarded by model-builders. Firstly, the quantum numbers…

High Energy Physics - Phenomenology · Physics 2021-01-05 Joe Davighi , Matthew Kirk , Marco Nardecchia

Given the hints of lepton-flavour non-universality in $B$-meson decays, leptoquarks (LQs) are enjoying a renaissance. We propose novel Large Hadron Collider (LHC) searches for such hypothetical states that do not rely on strong production…

High Energy Physics - Phenomenology · Physics 2021-05-17 Ulrich Haisch , Giacomo Polesello

The impact of possible sources of lepton-flavor mixing on $K \to \pi \nu\bar\nu$ decays is analysed. At the one-loop level lepton-flavor mixing originated from non-diagonal lepton mass matrices cannot generate a CP-conserving $K_L \to…

High Energy Physics - Phenomenology · Physics 2009-09-29 Yuval Grossman , Gino Isidori , Hitoshi Murayama

Recently, both ATLAS and CMS measured the decay $h\to\mu^+\mu^-$, finding a signal strength with respect to the Standard Model expectation of $1.2\pm0.6$ and $1.19\substack{+0.41+0.17\\-0.39 -0.16}$, respectively. This provides, for the…

High Energy Physics - Phenomenology · Physics 2021-07-14 Andreas Crivellin , Dario Mueller , Francesco Saturnino