相关论文: Anomalies in Bottom from new physics in Top
At present, there are several measurements of $B$ decays that exhibit discrepancies with the predictions of the Standard Model, and suggest the presence of new physics in $b\to s$ and $b \to c(u)$ quark level transitions. Motivated by the…
We consider one of the most significant deviations from the Standard Model: the forward-backward asymmetry of the b-quark measured at leptonic colliders. We investigate the possibility to solve this discrepancy by introducing new physics at…
We consider a flavour conserving two Higgs doublet model that consists of a type I (or X) quark sector and a generalized lepton sector where the Yukawa couplings of the charged leptons to the new scalars are not proportional to the lepton…
The Fermi effective theory of the weak interaction helped identify the structure of the electroweak sector of the Standard Model, and the chiral effective Lagrangian pointed towards QCD as the theory of the strong interactions. The Standard…
We study the constraints imposed by perturbative unitarity on the new physics interpretation of the muon $g-2$ anomaly. Within a Standard Model Effective Field Theory (SMEFT) approach, we find that scattering amplitudes sourced by effective…
In this paper we present updated constraints on the top-quark sector of the Standard Model Effective Field Theory using data available from Tevatron, LEP and the LHC. Bounds are obtained for the Wilson coefficients from a global fit…
We study single top quark production in association with a lepton-neutrino pair at the LHC within the framework of the Standard Model Effective Field Theory (SMEFT). We focus on relevant two-quark-two-lepton operators ($O^{3}_{lq}$,…
Following a proposal for an experiment with sensitivity to an electric dipole moment (EDM) of the muon $d_\mu$ of order $6\times10^{-23}\ e$ cm, three to four orders of magnitude below the current bound, but still seven orders of magnitude…
Charged lepton flavor violation (cLFV) processes, potentially important for various Beyond the Standard Model Physics scenarios are analyzed in the Standard Model Effective Field Theory (SMEFT) framework. We consider the most relevant 2…
At energies below the electroweak scale, baryon number $B$ and lepton number $L$ violating processes are of significant importance in identifying the nature of UV extensions of the Standard Model. The imprint of UV theories on low-energy…
We derive the causality and unitarity constraints on dimension 6 and dimension 8 Gluon field strength operators in the Standard Model Effective Field Theory (SMEFT). In the first part of the paper, we use the 'amplitude analysis' i.e.…
We review and update current limits on possible anomalous couplings of the top quark to gauge bosons. We consider data from top quark decay (as encoded in the $W$-boson helicity fractions) and single-top production (in the $t$-, $s$- and…
Modified interactions in the electroweak sector may lead to scattering amplitudes that grow with energy compared to their Standard Model (SM) counterparts. We present a detailed study of all $2\to2$ scattering amplitudes involving at least…
We present results from a complete next-to-leading order (NLO) calculation of $e^+e^-\rightarrow ZH$ in the Standard Model Effective Field Theory (SMEFT) framework, including all contributions from dimension-6 operators. At NLO, there are…
Supersymmetry is one of the best motivated possibilities for new physics at the TeV scale. However, both concrete string constructions and phenomenological considerations suggest the possibility that the physics at the TeV scale could be…
There are four models of tree-level new physics (NP) that can potentially simultaneously explain the $b \to s \mu^+ \mu^-$ and $b \to c \tau^- {\bar\nu}$ anomalies. They are the S3, U3 and U1 leptoquarks (LQs), and a triplet of SM-like…
The present approach relies on the SM chiral symmetry breaking pattern $SU(2)_L\otimes SU(2)_R\to SU(2)_{L+R}$, with the EW Goldstone bosons given in a non-linear realization and the Higgs boson described by an EW singlet field. In…
We replace the standard model scalar doublet by a doublet of vector fields and generate masses by dynamical symmetry breaking. Oblique radiative corrections are small if the new vector bosons ($ B^+$, $ B^0 $) are heavy. In this note it is…
The gauge-invariant operators up to dimension six in the low-energy effective field theory below the electroweak scale are classified. There are 70 Hermitian dimension-five and 3631 Hermitian dimension-six operators that conserve baryon and…
We present a class of models in the framework of gauge mediation supersymmetry breaking where the messenger fields transform in the adjoint representation of the Standard Model gauge symmetry. To avoid unacceptably light right-handed…