Search results for "ROWE"

Testing triplet fermions at the electron-positron and electron-proton colliders using fat jet signatures

2020

The addition of $SU(2)_L$ triplet fermions of zero hypercharge with the Standard Model (SM) helps to explain the origin of the neutrino mass by the so-called seesaw mechanism. Such a scenario is commonly know as the type-III seesaw model. After the electroweak symmetry breaking the mixings between the light and heavy mass eigenstates of the neutral leptons are developed which play important roles in the study of the charged and neutral multiplets of the triplet fermions at the colliders. In this article we study such interactions to produce these multiplets of the triplet fermion at the electron-positron and electron-proton colliders at different center of mass energies. We focus on the hea…

SU(2)×U(1)Gauge Invariance and the Shape of New Physics in RareBDecays

2014

New physics effects in B decays are routinely modeled through operators invariant under the strong and electromagnetic gauge symmetries. Assuming the scale for new physics is well above the electroweak scale, we further require invariance under the full standard model gauge symmetry group. Retaining up to dimension-six operators, we unveil new constraints between different new physics operators that are assumed to be independent in the standard phenomenological analyses. We illustrate this approach by analyzing the constraints on new physics from rare B(q) (semi-)leptonic decays.

FlexibleSUSY -- A spectrum generator generator for supersymmetric models

2014

We introduce FlexibleSUSY, a Mathematica and C++ package, which generates a fast, precise C++ spectrum generator for any SUSY model specified by the user. The generated code is designed with both speed and modularity in mind, making it easy to adapt and extend with new features. The model is specified by supplying the superpotential, gauge structure and particle content in a SARAH model file; specific boundary conditions e.g. at the GUT, weak or intermediate scales are defined in a separate FlexibleSUSY model file. From these model files, FlexibleSUSY generates C++ code for self-energies, tadpole corrections, renormalization group equations (RGEs) and electroweak symmetry breaking (EWSB) co…

Electroweak effects in intermediate energy physics

2008

A composite Heavy Vector Triplet in the ATLAS di-boson excess

2015

Composite vector resonances in the triplet of the SM SU$(2)_{L}$ gauge group are a universal prediction of "natural" new physics models involving a new strongly-interacting sector and are therefore among the most plausible new particles that the LHC could discover. We consider the possibility that one such triplet could account for the ATLAS excess in the invariant-mass spectrum of boson-tagged jets and we assess the compatibility of this hypothesis with all other relevant resonance searches. We find that the hypothesis is not excluded and that the predicted signal is close to the expected sensitivity of several channels, some of which show an upper fluctuation of the observed limit while o…

A flavour physics scenario for the 750 GeV diphoton anomaly

2016

A simple variant of a realistic flavor symmetry scheme for fermion masses and mixings provides a possible interpretation of the diphoton anomaly as an electroweak singlet ``flavon.'' The existence of TeV scale vectorlike T-quarks required to provide adequate values for Cabibbo-Kobayashi-Maskawa (CKM) parameters can also naturally account for the diphoton anomaly. Correlations between ${V}_{ub}$ and ${V}_{cb}$ with the vectorlike T-quark mass can be predicted. Should the diphoton anomaly survive in a future run, our proposed interpretation can also be tested in upcoming B and LHC studies.

LHC bounds on colored scalars

2019

We analyze the constraints on coloured scalar bosons imposed by the current LHC data at $\sqrt{s}=13$ TeV. Specifically, we consider an additional electroweak doublet of colour-octet scalars, satisfying the principle of Minimal Flavour Violation in order to fulfill the stringent experimental limits on flavour-changing neutral currents. We demonstrate that coloured scalars with masses below 800 GeV are already excluded, provided they are not fermiophobic.

Electroweak Symmetry Breaking and the Higgs Boson

2015

The first LHC run has confirmed the Standard Model as the correct theory at the electroweak scale, and the existence of a Higgs-like particle associated with the spontaneous breaking of the electroweak gauge symmetry. These lectures overview the present knowledge on the Higgs boson and discuss alternative scenarios of electroweak symmetry breaking which are already being constrained by the experimental data.

LHC constraints on two-Higgs doublet models

2014

The recent discovery of a Standard Model-like boson with mass of about 126 GeV seems to be the first direct information on the electroweak symmetry breaking mechanism. Using the available experimental data from the LHC and Tevatron we study the implications on the parameter space of the Two-Higgs Doublet Model extension of the Standard Model. The generic structure of the Aligned Two-Higgs Doublet Model (ATHDM) is imposed in the Yukawa sector; also the models with discrete Z2 symmetries are analyzed.

Search for Higgs andZBoson Decays toϕγwith the ATLAS Detector

2016

A search for the decays of the Higgs and Z bosons to a ϕ meson and a photon is performed with a pp collision data sample corresponding to an integrated luminosity of 2.7  fb^{-1} collected at sqrt[s]=13  TeV with the ATLAS detector at the LHC. No significant excess of events is observed above the background, and 95% confidence level upper limits on the branching fractions of the Higgs and Z boson decays to ϕγ of 1.4×10^{-3} and 8.3×10^{-6}, respectively, are obtained.