Related papers: Tree Level Unitarity Bounds for the Minimal B-L Mo…
We show that perturbative unitarity for $W_LW_L$ scattering places significant constraints on the Randall-Sundrum theory with two 3-branes, with matter confined to the TeV brane. The exchange of massive 4D Kaluza-Klein gravitons leads to…
We consider the supersymmetric extension of the Standard Model with neutrino Yukawa interactions and R-parity violation. We found that R-parity breaking term \lambda \nu H_u H_d leads to an additional F-type contribution to the Higgs scalar…
We consider supersymmetric models that include particles beyond the Minimal Supersymmetric Standard Model (MSSM) with masses in the TeV range, and that couple significantly to the MSSM Higgs sector. We perform a model-independent analysis…
We consider the neutralino mass matrix in a supersymmetric theory based on SU(2) $\times$ U(1) gauge group with arbitrary number of singlet, doublet and triplet Higgs superfields. We derive an upper bound on the mass of the lightest…
Three extensions of the scalar sector of the Standard Model are considered: one extra isosinglet, one extra isotriplet, two extra isotriplets (the Georgi-Machacek model). Double Higgs boson production cross section is calculated in all…
We study a bound system of N identical bosons interacting by model pair potentials of the form V(r) = A sgn(p)r^p + B/r^2, A > 0, B >= 0. By using a variational trial function and the `equivalent 2-body method', we find explicit upper and…
We consider a procedure for directly constructing general tree-level four-particle scattering amplitudes of massive spinning particles that are consistent with the usual requirements of Lorentz invariance, unitarity, crossing symmetry, and…
The Higgs discovery has given us the Higgs-gauge sector as a new handle to search for physics beyond the Standard Model. This includes physics scenarios originally linked to massive gauge boson scattering at high energies. We investigate…
Using asymptotic helicity amplitudes for Vector-Vector, Vector-Higgs and Higgs-Higgs scattering, we establish the unitarity constraints on the $SU(2)_c$ conserving and $W_\mu$ depending interactions, which at sufficiently high energies may…
The triviality and vacuum stability bounds on the Higgs-boson mass were revisited in presence of weakly-coupled new interactions parameterized in a model-independent way by effective operators of dimension 6. It was shown that for the scale…
A possible extension of the Standard Model of elementary particles is Gauge-Higgs unification, where the Higgs field is identified with (some of) the extra dimensional components of a five-dimensional gauge field. In this scenario there is…
This article reviews the theoretical constraints on the scalar potential of a general extension of the Standard Model that encompasses a $SU(3)_c\times SU(3)_L\times U(1)_X$ gauge symmetry. In this respect, the boundedness-from-below is…
I point out that $B \to X_q \l^+ \l^-$ decays $(q = s, d)$ are sensitive probes of possible violation of CKM unitarity. I compute the decay rates and asymmetries in a minimal extension of the Standard Model containing an additional…
We present twin Higgs models based on the extension of the Standard Model to left-right symmetry that protect the weak scale against radiative corrections up to scales of order 5 TeV. In the ultra-violet the Higgs sector of these theories…
If the recently discovered Higgs boson's couplings deviate from the Standard Model expectation, we may anticipate new resonant physics in the weak boson fusion channels resulting from high scale unitarity sum rules of longitudinal gauge…
New spin-1 particles with masses below the weak scale are present in many theories of beyond Standard Model (SM) physics. In this work, we extend previous analyses by systematically considering the couplings of such a vector to the bosonic…
We investigate non perturbatively scattering properties of Goldstone Bosons in an SU(2) gauge theory with two Wilson fermions in the fundamental representation. Such a theory can be used to build extensions of the Standard Model that…
A spontaneously broken SU(2) theory is the simplest generalization of the Abelian Higgs model, containing three equally massive vector bosons and a single Higgs scalar. A strictly diagrammatic proof is presented of the tree-level unitarity…
It is proved that the minimum of a general two Higgs doublet models' potential is stable at tree level. A relation between stability and flavour changing neutral currents at tree level is shown.
A complete parton level analysis of lv + four jets production at the LHC is presented, including all processes at order O(alpha^6), O(alpha^4*alpha_s^2) and O(alpha^2*alpha_s^4). The infinite Higgs mass scenario, which is considered as a…