相关论文: Doubling down on down-type diquarks
We analyse the constraints and some of the phenomenological implications of a class of two Higgs doublet models where there are flavour-changing neutral currents (FCNC) at tree level but the potentially dangerous FCNC couplings are…
Until now the focus within the direct search for supersymmetry has mainly been on flavour diagonal observables. Recently lepton flavour violating signals at future electron positron colliders have been studied. There is now an opportunity…
New physics can manifest itself by an appreciable increase of the decay rate of top quarks in rare flavour-changing final states. Exploiting the large top quark production rate at the LHC, we bound four-fermion operators contributing to…
We conduct a comprehensive investigation into the flavour phenomenology and collider signatures of flavon of $\mathcal{Z}_{\rm N} \times \mathcal{Z}_{\rm M}$ flavour symmetries for the soft symmetry-breaking scenario and a new…
We construct a class of two Higgs doublets models with a 4th sequential generation of fermions that may effectively accommodate the low energy characteristics and phenomenology of a dynamical electroweak symmetry breaking scenario which is…
In the contest of a Two Higgs Doublet Model without flavor conservation, the presence of Flavor Changing Neutral Scalar Currents may affect in particular the couplings of the top quark. Some ideas on how to look for new signals from Flavor…
Many composite Higgs models predict the existence of vector-like quarks with masses outside the reach of the LHC, e.g. $m_Q \gtrsim 2$ TeV, in particular if these models contain a dark matter candidate. In such models the mass of the new…
We present a comprehensive analysis of the discovery reach and exclusion limits for an ultraheavy diquark scalar (7-9.5 TeV) decaying into a pair of vectorlike quarks (1.5-2 TeV) at the HL-LHC. Building on an improved signal selection…
The possibility of detecting double flavor violating top quark transitions at future colliders is explored in a model-independent manner using the effective Lagrangian approach through the $t \to u_i\tau \mu$ ($u_i=u,c$) decays. A Yukawa…
We use ATLAS and CMS searches in the mono-jet + missing energy and mono-photon + missing energy final state to set limits on the couplings of dark matter to quarks and gluons. Working in an effective field theory framework we compare…
We consider large classes of chiral extensions of the Standard Model, including new quark generations that do not involve additional neutrinos as well as lepton generations without quarks. An analysis of renormalization flows of Yukawa and…
Simplified models provide a useful tool to conduct the search and exploration of physics beyond the Standard Model in a model-independent fashion. In this work we consider the complementarity of indirect searches for new physics in Higgs…
Motivated by our limited knowledge of the Higgs couplings to first two generation fermions, we analyze the collider phenomenology of a class of two Higgs doublet models (2HDMs) with a non-standard Yukawa sector. One Higgs doublet is mainly…
A discovery of flavour-changing Higgs-boson decays would constitute an undeniable signal of new physics. We derive model-independent constraints on the tch and tuh couplings that arise from the bounds on hadronic electric dipole moments.…
We explore the capability of the Tevatron and LHC as well as other future hadron colliders to place limits on the possible existence of flavor-independent $q \bar q \gamma\gamma$ contact interactions which can lead to an excess of high…
Imposing the theoretical constraints from vacuum stability, unitarity and perturbativity as well as the experimental constraints from the electroweak precision data, flavor observables and the non-observation of additional Higgs at…
A charged Higgs boson is a clear signal for an extended Higgs sector, as for example predicted by supersymmetry. Squark mixing can significantly change the pattern of charged-Higgs production and most notably circumvent the chiral…
We propose two new analysis strategies for studying charm and beauty quarks at colliders. The first strategy is aimed at testing the kinematics of heavy-flavor quarks within an identified jet. Here, we use the SoftDrop jet-declustering…
A common lore has arisen that beyond the Standard Model (BSM) particles, which can be searched for at current and proposed experiments, should have flavorless or mostly third-generation interactions with Standard Model quarks. This…
We explore signatures related to squark decays in the framework of non-minimally flavour-violating Supersymmetry. We consider a simplified model where the lightest squark consists of an admixture of charm and top flavour. By recasting the…