2,502 research outputs found
LHC Benchmark Scenarios for the Real Higgs Singlet Extension of the Standard Model
We present benchmark scenarios for searches for an additional Higgs state in
the real Higgs singlet extension of the Standard Model in Run 2 of the LHC. The
scenarios are selected such that they fulfill all relevant current theoretical
and experimental constraints, but can potentially be discovered at the current
LHC run. We take into account the results presented in earlier work and update
the experimental constraints from relevant LHC Higgs searches and signal rate
measurements. The benchmark scenarios are given separately for the low mass and
high mass region, i.e. the mass range where the additional Higgs state is
lighter or heavier than the discovered Higgs state at around 125 GeV. They have
also been presented in the framework of the LHC Higgs Cross Section Working
Group.Comment: 23 pages, 9 tables, 4 figures. arXiv admin note: text overlap with
arXiv:1501.02234; v2: one subsection, one figure, and some references added,
minor errors corrected. Corresponds to published journal versio
Constraining Extended Scalar Sectors at the LHC and beyond
We give a brief overview of beyond the Standard Model (BSM) theories with an
extended scalar sector and their phenomenological status in the light of recent
experimental results. We discuss the relevant theoretical and experimental
constraints, and show their impact on the allowed parameter space of two
specific models: the real scalar singlet extension of the Standard Model (SM)
and the Inert Doublet Model. We emphasize the importance of the LHC
measurements, both the direct searches for additional scalar bosons, as well as
the precise measurements of properties of the Higgs boson of mass 125 GeV. We
show the complementarity of these measurements to electroweak and dark matter
observables.Comment: 18 pages, 8 figures; prepared for submission to MPLA (invited review)
v2: several references and small text modification added to align with
journal version. 2 small errors in plots correcte
The Electroweak Phase Transition in the Inert Doublet Model
We study the strength of a first-order electroweak phase transition in the
Inert Doublet Model (IDM), where particle dark matter (DM) is comprised of the
lightest neutral inert Higgs boson. We improve over previous studies in the
description and treatment of the finite-temperature effective potential and of
the electroweak phase transition. We focus on a set of benchmark models
inspired by the key mechanisms in the IDM leading to a viable dark matter
particle candidate, and illustrate how to enhance the strength of the
electroweak phase transition by adjusting the masses of the yet undiscovered
IDM Higgs states. We argue that across a variety of DM masses, obtaining a
strong enough first-order phase transition is a generic possibility in the IDM.
We find that due to direct dark matter searches and collider constraints, a
sufficiently strong transition and a thermal relic density matching the
universal DM abundance is possible only in the Higgs funnel regime.Comment: 22 pages, 1 figure. Improved comments on gauge invariance. Matches
published versio
The Not-So-Well Tempered Neutralino
Light electroweakinos, the neutral and charged fermionic supersymmetric
partners of the Standard Model gauge bosons
and of the two Higgs doublets, are an important target for
searches for new physics with the Large Hadron Collider (LHC). However, if the
lightest neutralino is the dark matter, constraints from direct dark matter
detection experiments rule out large swaths of the parameter space accessible
to the LHC, including in large part the so-called "well-tempered" neutralinos.
We focus on the Minimal Supersymmetric Standard Model (MSSM) and explore in
detail which regions of parameter space are not excluded by null results from
direct dark matter detection, assuming exclusive thermal production of
neutralinos in the early universe, and illustrate the complementarity with
current and future LHC searches for electroweak gauginos. We consider both
bino-Higgsino and bino-wino "not-so-well-tempered" neutralinos, i.e. we include
models where the lightest neutralino constitutes only part of the cosmological
dark matter, with the consequent suppression of the constraints from direct and
indirect dark matter searches.Comment: 14 pages, 6 figures; v2: minor modifications, matches published
versio
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