Motivated by additional experimental hints of Lepton Flavour Universality violation in B decays, both charged- and neutral-current processes, we analyse the ingredients necessary to provide a combined description these phenomena. By means an Effective Field Theory (EFT) approach, based on hypothesis New Physics coupled predominantly third generation left-handed quarks leptons, show how this is possible. We demonstrate, particular, solve problems posed electroweak precision tests direct...

In view of recent experimental indications violations Lepton Flavor Universality (LFU) in B decays, we analyze constraints and implications LFU interactions, both using an effective theory approach, explicit dynamical model. We show that a simple model based on SU(2) L triplet massive vector bosons, coupled predominantly to third generation fermions (both quarks leptons), can significantly improve the description present data. particular, decreases tension between data SM predictions...

We confront the indications of lepton flavor universality (LFU) violation observed in semi-tauonic $B$ meson decays with new physics (NP) searches using high $p_T$ tau leptons at LHC. Using effective field theory arguments we correlate possible non-standard contributions to charged currents $\tau^+ \tau^-$ signature energy hadron colliders. Several representative standard model extensions put forward explain anomaly are examined detail: (i) weak triplet color-neutral vector resonances, (ii)...

The vector leptoquark representation, $U_\mu = (3,1,2/3)$, was recently identified as an exceptional single mediator model to address experimental hints on lepton flavour universality violation in semileptonic $B$-meson decays, both neutral ($b \to s \mu \mu$) and charged c \tau \nu$) current processes. Nonetheless, it is well-known that massive vectors crave ultraviolet (UV) completion. We present the first full-fledged UV complete calculable gauge which incorporates this scenario while...

We construct a model of quark-lepton unification at the TeV scale based on an $SU(4)$ gauge symmetry, while still having acceptable neutrino masses and enough suppression in flavor changing neutral currents. An approximate $U(2)$ symmetry is artifact family-dependent charges leading to natural realization CKM mixing matrix. The predicts sizeable violation PMNS unitarity as well vector leptoquark $U_1^\mu = ({\bf 3}, {\bf 1}, 2/3)$ which can be produced LHC -- both effects within reach future...

A bstract Rare b hadron decays are considered excellent probes of new semileptonic four-fermion interactions microscopic origin. However, the same also correct high-mass Drell-Yan tails. In this work, we revisit first statement in context complementarity and chart space short-distance physics that could show up rare decays. We analyze latest → qℓ + ℓ − measurements, where q = d or s e μ , including most recent LHCb $$ {R}_{K^{\left(\ast \right)}} <mml:math...

A bstract We propose a mechanism that allows for sizeable flavour violation in quark-lepton currents, while suppressing changing neutral currents quark-quark and lepton-lepton sectors. The is applied to the recently proposed “4321” renormalizable model, which can accommodate current experimental anomalies B -meson decays, both charged remaining consistent with all other indirect electroweak precision measurements direct searches at high- p T . To support this claim, we present an exhaustive...

We speculate about the origin of recent excess at $$\sim $$ 750 GeV in diphoton resonance searches observed by ATLAS and CMS experiments using first 13 TeV data. Its interpretation as a new scalar produced gluon fusion decaying to photons is consistent with all relevant exclusion bounds from 8 LHC run. provide simple phenomenological framework parametrize properties show model-independent way that, if fusion, additional colored charged particles are required. Finally, we discuss some...

The basic features of quark and lepton mass matrices can be successfully explained by natural minima a generic potential with dynamical Yukawa fields invariant under the $[\mathrm{SU(3)}]^5\times \mathcal{O}(3)$ flavor symmetry. If this symmetry is gauged, in order to avoid potentially dangerous Goldstone bosons, small perturbations are added exactly fit observed pattern fermion masses, spectrum massive gauge bosons naturally explain hints for new physics $b\to s \ell^+\ell^-$ transitions,...

We investigate the crossing-symmetry relation between b→cτ^{-}ν[over ¯] decay and bc[over ¯]→τ^{-}ν[over scattering to derive direct correlations of new physics in semitauonic B-meson decays mono-tau signature at LHC (pp→τ_{h}X+MET). Using an exhaustive set effective operators heavy mediators we find that current ATLAS CMS data constrain scenarios addressing anomalies B decays. Pure tensor solutions, completed by leptoquark, right-handed W_{R}^{'} or are challenged our analysis. Furthermore,...

We implement scalar and vector leptoquark (LQ) models in the universal FeynRules output (UFO) format assuming Standard Model fermion content conservation of baryon lepton numbers. Scalar LQ implementations include next-to-leading order (NLO) QCD corrections. report NLO inclusive cross sections proton-proton collisions at 13 TeV, 14 27 TeV for all on-shell production processes. These comprise (i) pair ($p p \to \Phi \Phi$) (ii) single + \ell$) initial quark flavours ($u$, $d$, $s$, $c$, $b$)....

A bstract We provide an ultraviolet (UV) complete model for the R ( D (∗) ) anomalies, in which additional contribution to semi-tauonic b → c transitions arises from decay a right-handed sterile neutrino via exchange of TeV-scale SU(2) L singlet W ′ . The is based on extension Standard Model (SM) hypercharge group, U(1) Y , V × gauge containing several pairs heavy vector-like fermions. present comprehensive phenomenological survey model, ranging low-energy flavor physics, direct searches at...

We investigate the impact of flavour-conserving, non-universal quark-lepton contact interactions on dilepton invariant mass distribution in $p~p \to \ell^+ \ell^-$ processes at LHC. After recasting recent ATLAS search performed 13 TeV with 36.1 fb$^{-1}$ data, we derive best up-to-date limits full set 36 relevant four-fermion operators, as well estimate sensitivity achievable HL-LHC. discuss how these high-$p_T$ measurements can provide complementary information to low-$p_T$ rare meson...

We revisit the physics of neutrino magnetic moments, focusing in particular on case where right-handed, or sterile, neutrinos are heavier (up to several MeV) than left-handed Standard Model neutrinos. The discussion is centered around idea detecting an upscattering event mediated by a transition moment dark matter experiment. Considering from all known sources, as well including available data XENON1T and Borexino, we derive strongest up-to-date exclusion limits active-to-sterile moment....

We discuss how to perform consistent extractions of anomalous triple gauge couplings (aTGC) from electroweak boson pair production at the LHC in Standard Model Effective Field Theory (SMEFT). After recasting recent ATLAS and CMS searches pp → W Z(W ) ℓ′νℓ+ℓ−(νℓ) channels, we find that: (a) working consistently order Λ−2 SMEFT expansion existing aTGC bounds Higgs LEP-2 data are not improved, (b) strong limits quoted by experimental collaborations due partial Λ−4 corrections (dimension-6...

We present a combined analysis of LHC Higgs data (signal strengths) together with LEP-2 WW production measurements. To characterize possible deviations from the standard model (SM) predictions, we employ framework an effective field theory (EFT) where SM is extended by higher-dimensional operators suppressed mass scale new physics Λ. The performed consistently at order Λ(-2) in EFT expansion keeping all relevant operators. While two sets suffer flat directions, they impose stringent...

We present a systematic survey of possible short-distance new-physics effects in (semi)leptonic charged- and neutral-current charmed meson decays. Using the Standard Model Effective Field Theory (SMEFT) to analyze most relevant experimental data at low high energies, we demonstrate striking complementarity between charm decays invariant mass lepton tails LHC. Interestingly enough, high-$p_T$ Drell-Yan offer competitive constraints on new physics scenarios. Furthermore, full set correlated...

The Standard Model (SM) is augmented with a U(1)B−3Lμ gauge symmetry spontaneously broken above the TeV scale when an SM-singlet scalar condenses. Scalar leptoquarks S1(3)=(3‾,1(3),13) charged under mediate intriguing effects observed in muon (g−2), RK(⁎), and b→sμ+μ− angular distributions, while generically evading all other phenomenological constraints. fermionic sector minimally extended three right-handed neutrinos, successful type-I seesaw mechanism realized. Charged lepton flavor...

A bstract The high-energy tails of charged- and neutral-current Drell-Yan processes provide important constraints on the light quark anti-quark parton distribution functions (PDFs) in large- x region. At same time, short-distance new physics effects such as those encoded by Standard Model Effective Field Theory (SMEFT) would induce smooth distortions to tails. In this work, we assess for first time interplay between PDFs EFT high-mass at LHC quantify impact that consistent joint...

A bstract We develop an economical theoretical framework for combined explanations of the flavor physics anomalies involving muons: ( g − 2) μ , $$ {R}_{K^{\left(\ast \right)}} <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>R</mml:mi> <mml:msup> <mml:mi>K</mml:mi> <mml:mfenced> <mml:mo>∗</mml:mo> </mml:mfenced> </mml:msup> </mml:msub> </mml:math> and b → sμ + angular distributions branching ratios, that was first initiated by some us in ref. [1]. The Standard...

Abstract We propose an economical model to address the mass hierarchies of quarks and charged leptons. The light generations left-handed fermions form doublets under $$ \textrm{SU}(2) <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mtext>SU</mml:mtext> <mml:mo>(</mml:mo> <mml:mn>2</mml:mn> <mml:mo>)</mml:mo> </mml:mrow> </mml:math> flavor symmetry, which is gauged. generational emerge from three independent rank-one contributions Yukawa matrices: one a...

We study implications of large lepton-quark-leptoquark couplings for direct leptoquark searches at Large Hadron Collider. present all existing flavor constraints on the strength these assuming that leptoquarks under consideration interact exclusively with charged leptons and quarks same generation. find can have sizeable to Standard Model fermions. This insures a self consistency our study. discuss production mechanisms LHC demonstrate importance inclusion t-channel pair and, in particular,...

We speculate about the possible interpretations of recently observed excess in $h \to \tau \mu$ decay. derive a robust lower bound on Higgs boson coupling strength to tau and muon, even presence most general new physics affecting other properties. Then we reevaluate complementary indirect constraints coming from low energy observables as well theoretical considerations. In particular, tentative signal should lead $\tau \mu \gamma$ at rates which could be Belle II. turn show that, barring...