Related papers: Constraints on vector resonances from a strong Hig…
An evidence for a diphoton resonance at a mass of 750 GeV has been observed in the data collected at the LHC run at a center of mass energy of 13 TeV. We explore several interpretations of this signal in terms of Higgs-like resonances in a…
A search for a hypothetical heavy scalar particle, $X$, decaying into a singlet scalar particle, $S$, and a Standard Model Higgs boson, $H$, using 140 fb$^{-1}$ of proton-proton collision data at the centre-of-mass energy of 13 TeV recorded…
The recent announcement of a discovery of a possible Higgs-like particle -its spin and parity is yet to be determined- at the LHC with a mass of 126 GeV necessitates a fresh look at the nature of the electroweak symmetry breaking, in…
We study an extension of the Standard Model featuring a hidden sector that consists of a new scalar charged under a new SU$(N)_D$ gauge group, singlet under all Standard Model gauge interactions, and coupled with the Standard Model only via…
Using a general effective Lagrangian implementing the chiral symmetry breaking SU(2)L x SU(2)R -> SU(2){L+R}, we present a one-loop calculation of the oblique S and T parameters within electroweak strongly-coupled models with a light…
Vector-Like (VL) quarks arise in the main alternatives to the supersymmetric extensions of the Standard Model (SM). Given the experimental possibility of a 125 GeV Higgs boson with rates significantly different from the SM expectations, it…
In the two Higgs doublet model, perturbativity breaks down below the Planck scale: For top mass values 170-180 GeV, the Yukawa coupling reaches the pole below 1000 TeV, if the ratio of vev's v_u/v_d is below 1. We discuss top condensate…
We consider a minimal model where the Higgs boson arises as an elementary pseudo-Nambu-Goldstone boson. The model is based on an extended scalar sector with global SO(5)/SO(4) symmetry. To achieve the correct electroweak symmetry breaking…
We study in a bottom-up approach the theoretically consistent description of additional resonances in the electroweak sector beyond the discovered Higgs boson as simplified models. We focus on scalar and tensor resonances. Our formalism is…
We describe a natural UV complete theory with a composite little Higgs. Below a TeV we have the minimal Standard Model with a light Higgs, and an extra neutral scalar. At the TeV scale there are additional scalars, gauge bosons, and…
The Standard Model (SM) with a light Higgs boson provides a very good description of the precision electroweak observable data coming from the LEP, SLD and Tevatron experiments. Most of the observables, with the notable exception of the…
Hidden sector SUSY breaking where charged hidden sector fields obtain SUSY breaking vevs once seemed common in dynamical SUSY breaking (DSB). In such a case, scalars can obtain large masses but gauginos and A-terms gain loop-suppressed…
The last years have seen a great development in our understanding of particle physics at the weak scale. Precision electroweak observables have played a key role in this process and their values are consistent, within the Standard Model…
A search for heavy pseudoscalar ($A$) and scalar ($H$) Higgs bosons decaying into a top quark pair ($t\bar{t}$) has been performed with 20.3 fb$^{-1}$ of proton--proton collision data collected by the ATLAS experiment at the Large Hadron…
We study models in which the Higgs sector is extended by a single scalar electroweak multiplet Z with isospin T=5/2 (sextet) or 7/2 (octet) and the same hypercharge as the Standard Model Higgs doublet, in which Z is odd under a global Z2…
With the Higgs search program already quite mature, there is the exciting possibility of discovering a new particle with rates near that of the SM Higgs. We consider models with a signal in $\gamma \gamma$ below the SM Higgs mass, taking…
The phenomenology of the electroweak symmetry breaking sector is expected to involve resonances decaying preferentially into heavy fermions. Three recent CDF analyses are reviewed and used to constrain Higgs and Technicolor models.
In a recent paper, we introduced a new Little Higgs model, which contains the gauge structure $SU(2)^3\times U(1)$, embedded in an approximate global $SO(5)\times SO(5)$ symmetry. After breaking to the standard model, $SU(2)_L \times…
In the standard Higgs model of electroweak symmetry breaking, the Higgs boson is associated with both vector-boson and fermion mass generation. In contrast, we discuss a two-Higgs-doublet model in which these masses are associated with two…
We study electroweak symmetry breaking in minimal composite Higgs models $SU(4)/Sp(4)$ with purely fermionic UV completions based on a confining Hypercolor gauge group and find that the extra Higgs potential from the underlying preon mass…