Related papers: Testing Leptoquark/EFT in $\bar B \to D^{(*)} l\ba…
With the absence of the direct detection of new physics and the large data set collected at the LHC, the search for indirect effects in precision measurements became popular. Effective field theories enable to interpret these effects that…
We show the outstanding potential of the High-Luminosity LHC (HL-LHC) to discover charged lepton flavor violation (cLFV) via the ultra-peripheral process $\gamma\gamma \to e^\pm\mu^\mp$. Using a gauge-invariant Effective Field Theory (EFT)…
We examine various scenarios in which the Standard Model is extended by a light leptoquark state to solve for one or both $B$-physics anomalies, viz. $R_{D^{(\ast)}}^\mathrm{exp}> R_{D^{(\ast)}}^\mathrm{SM}$ or/and…
The energy spectrum of the lepton(s) in e^+e^- --> tt-bar --> l^{+-} ...../l^+l^-..... at next linear colliders (NLC) is studied for arbitrary longitudinal beam polarizations as a possible test of new physics in top-quark couplings. The…
We study the $\bar{B}\to D(D^*) \ell^-\bar{\nu}_{\ell}$ decays based on the up-to-date available inputs from experiments and the lattice. First, we review the standard model (SM) predictions of the different observables associated with…
The Standard Model (SM) has no flavor-changing neutral current (FCNC) processes at the tree level. Therefore, processes featuring FCNC in new physics are tightly constrained by data. Typically, the lower bounds on the scale of new physics…
We investigate the $\Lambda_c \to \Lambda \ell^{+} \nu_\ell$ decay with a focus on potential new physics (NP) effects in the $\ell = \mu$ channel. We employ an effective Hamiltonian within the framework of the Standard Model Effective Field…
We investigate the viability of extending the Standard Model with $S_1$ and $S_3$ scalar leptoquarks when the flavour structure is parametrized in terms of Froggatt-Nielsen charges. In contrast to a similar analysis with a vector…
A search for the charged-lepton-flavor-violating process $Z\rightarrow e\mu$ is presented, using 139 fb$^{-1}$ of $\sqrt{s}=13$ TeV $pp$ collision data collected by the ATLAS experiment at the LHC. An excess in the $e\mu$ invariant mass…
We shortly review and emphasize how l_j -> l_i gamma experiments and the searches for lepton e.d.m. are constraining New Physics model building. They are pure signals of new phenomena around the TeV scale since the SM contributions are…
We derive new bounds on scalar leptoquark couplings from K^0 K^0 bar, D^0 D^0 bar and B^0 B^0 bar mixing. Although leptoquarks contribute to these processes only at one loop, their contribution is large, due to the lack of GIM cancelation.…
We compare the sensitivity of precision measurements of lepton flavour observables to the reach of the LHC in a case study of lepton-flavour violating operators of dimension six with two leptons and two quarks. For light quarks precision…
The P2 experiment aims at high-precision measurements of the parity-violating asymmetry in elastic electron-proton and electron-$^{12}$C scatterings with longitudinally polarized electrons. We discuss here the sensitivity of P2 to…
Lepton Flavor Violating (LFV) observables such as $\mu\to e\gamma$, $\mu\to 3e$ and $\mu N \to eN$ are among the best probes for new physics at the TeV scale. In the near future the bounds on these observables will improve by many orders of…
Leptoquarks (LQ) with couplings to the third generation of Standard Model (SM) quarks have been proposed as possible explanations of the flavour anomalies indicating the violation of lepton flavour universality (LFV). The CMS collaboration…
In the framework of gauged flavour symmetries, new fermions in parity symmetric representations of the standard model are generically needed for the compensation of mixed anomalies. The key point is that their masses are also protected by…
Present measurements of b->c tau nu and b->u tau nu transitions differ from the standard model predictions of lepton flavor universality by almost 4sigma. We examine new physics interpretations of this anomaly. An effective field theory…
We revisit the constraints on semileptonic operators derived from the mono-$\tau$ high-$p_T$ events in $pp$ collisions at LHC. Like in previous studies, we obtain limits on the New Physics couplings from the CMS data much stronger than from…
We study limits from dilepton searches on leptoquark completions to the Standard Model in the parameter space motivated by anomalies in the $b \rightarrow s$ sector. After a full Run-2 analysis by LHCb, the disparity in lepton flavour…
This is a brief pedagogic introduction to searches for new physics with top quarks. It covers indirect searches for heavy new particles based on standard model effective theory and direct searches for new signatures of a light hidden…