相关论文: Hunting for Vectorlike Quarks
We study cascade decays of heavy neutral Higgs bosons through vectorlike quarks. We focus on scenarios where decay modes into pairs of vectorlike quarks are not kinematically open which extends the sensitivity of the LHC to larger masses.…
We study $4b+2\tau$ and $4b+1\tau$ signatures of heavy neutral and charged Higgs bosons originating from cascade decays of pair-produced new quarks. Decays of vectorlike quarks through heavy Higgses can easily dominate in the two Higgs…
We consider supersymmetric extensions of the standard model with a vector-like doublet $(T \, B)$ of quarks with charge $2/3$ and $-1/3$, respectively. Compared to non-supersymmetric models, there is a variety of new decay modes for the…
In extensions of two Higgs doublet models with vectorlike quarks, the decays of vectorlike quarks may easily be dominated by cascade decays through charged or neutral Higgs bosons leading to signatures with 6 top or bottom quarks. Since top…
The Higgs boson decay to massive bottom quarks has the largest branching ratio. The decay is mainly induced by the bottom-quark Yukawa coupling with the decay rate calculated up to $\mathcal{O}(\alpha_s^4)$ assuming the massless final-state…
A search for the standard model Higgs boson (H) decaying to a b-quark pair when produced in association with weak vector bosons (V) is reported for the following modes: W(mu,nu)H, W(e,nu)H, Z(mu,mu)H, Z(e,e)H and Z(nu,nu)H. The search is…
In extensions of two Higgs doublet models with vectorlike quarks, the decays of vectorlike quarks may be easily dominated by cascade decays through charged or neutral Higgs bosons leading to signatures with 6 top or bottom quarks. Since top…
New vectorlike fermions that mix with the third generation can significantly affect the tau and b Yukawa couplings. Consistent with precision electroweak measurements, the width of the Higgs boson to tau tau, b b can be reduced by O(1) with…
The vector-like quark model is one of the extensions of the standard model (SM) of particle physics. The simplest version of this model introduces a vector-like singlet quark which can mix with SM quarks and give rise to new contributions…
We show that both flavor-conserving and flavor-violating Yukawa couplings of the Higgs boson to first- and second-generation quarks can be probed by measuring rare decays of the form h->MV, where M denotes a vector meson and V indicates…
An SU(2) vectorlike singlet quark with a charge either +2/3 (t') or -1/3 (b') is predicted in many extensions of the Standard Model. The mixing of these quarks with the top or bottom lead to Flavor Changing Yukawa Interactions and Neutral…
We study Little Higgs models based on a SU(3)_1 x SU(3)_2 global symmetry and with two scales (the two vacuum expectation values f_{1,2}) substantially different. We show that all the extra vector boson fields present in these models may be…
Yukawa couplings of the first quark generation are notoriously difficult to constrain due to their small values within the Standard Model. Here we propose Higgs off-shell production, with the Higgs boson decaying to four leptons, as a probe…
A search is performed for a vector-like heavy T quark that is produced in pairs and that decays to a top quark and a Higgs boson. The data analysed correspond to an integrated luminosity of 19.7 inverse femtobarns collected with the CMS…
The small mass of the bottom quark, relative to its weak isospin partner, the top quark, makes the bottom an effective probe of new physics in Higgs and top sectors. We study the Higgs boson production associated with bottom quarks,…
New vector-like quarks can mix sizably with first generation Standard Model quarks without conflicting with current experimental constraints. Searches for such new quarks have been performed in pair production and electroweak single…
We consider an extension of the Standard Model involving a singlet Higgs and down type vector-like quarks in the light of the current LHC Higgs data. For a good range of the parameters of the Higgs potential, and a mass range for the heavy…
We present predictions for the Higgs boson decay into four bottom quarks in the standard model and via light exotic scalars retaining full bottom-quark mass dependence. In the SM the decay can be induced either by the Yukawa couplings of…
We present a detailed analysis of the rare exclusive Higgs-boson decays into a single vector meson and a photon and investigate the possibility of using these processes to probe the light-quark Yukawa couplings. We work with an effective…
A search is presented for production of a heavy up-type quark (t') together with its antiparticle, assuming a significant branching ratio for subsequent decay into a W boson and a b quark. The search is based on 4.7 fb^-1 of pp collisions…