Search results for "Higgs mechanism"
showing 10 items of 32 documents
Observing Higgs boson production through its decay into gamma-rays: A messenger for Dark Matter candidates
2012
In this Letter, we study the gamma-ray signatures subsequent to the production of a Higgs boson in space by dark matter annihilations. We investigate the cases where the Higgs boson is produced at rest or slightly boosted and show that such configurations can produce characteristic bumps in the gamma-ray data. These results are relevant in the case of the Standard Model-like Higgs boson provided that the dark matter mass is about 63 GeV, 109 GeV or 126 GeV, but can be generalized to any other Higgs boson masses. Here, we point out that it may be worth looking for a 63 GeV line since it could be the signature of the decay of a Standard Model-like Higgs boson produced in space, as in the case…
Search for Low-Mass Dark-Sector Higgs Bosons
2012
See paper for full list of authors - 7 pages, 5 postscript figures, submitted to Phys. Rev. Lett; Recent astrophysical and terrestrial experiments have motivated the proposal of a dark sector with GeV-scale gauge boson force carriers and new Higgs bosons. We present a search for a dark Higgs boson using 516 fb-1 of data collected with the BABAR detector. We do not observe a significant signal and we set 90% confidence level upper limits on the product of the Standard Model-dark sector mixing angle and the dark sector coupling constant.
No-scale N=4 supergravity coupled to Yang-Mills: the scalar potential and super-Higgs effect
2002
We derive the scalar potential of the effective theory of type IIB orientifold with 3-form fluxes turned on in presence of non abelian brane coordinates. N=4 supergravity predicts a positive semidefinite potential with vanishing cosmological constant in the vacuum of commuting coordinates, with a classical moduli space given by three radial moduli and three RR scalars which complete three copies of the coset (U(1,1+n)/U(1)\otimes U(1+n)), together with 6n D3-branes coordinates, n being the rank of the gauge group G. Implications for the super Higgs mechanism are also discussed.
GENERALIZED GAUGE TRANSFORMATIONS AND HIDDEN SYMMETRY IN THE STANDARD MODEL
1992
A recently proposed, new construction of the Standard Model based on the graded Lie algebra SU (2|1) is analyzed in some depth. The essential ingredient is an algebraic superconnection which incorporates both the gauge fields and the Higgs fields and whose curvature automatically leads to a spontaneously broken realization of the theory. The mechanism of hiding the original algebraic structure is unorthodox and is due to the specific, "noncommutative" realization of SU (2|1). The model is characterized by a constant background supercurvature which is invariant under arbitrary, constant SU (2|1) gauge transformations. This background field whose effect is analogous to the action of a consta…
Light composite Higgs and precision electroweak measurements on the Z resonance: An update
2005
We update our analysis of technicolour theories with techniquarks in higher dimensional representations of the technicolour gauge group in the light of the new electroweak precision data on the Z resonance.
Vacuum stability with spontaneous violation of lepton number
2016
The vacuum of the Standard Model is known to be unstable for the measured values of the top and Higgs masses. Here we show how vacuum stability can be achieved naturally if lepton number is violated spontaneously at the TeV scale. More precise Higgs measurements in the next LHC run should provide a crucial test of our symmetry breaking scenario. In addition, these schemes typically lead to enhanced rates for processes involving lepton flavour violation .
Invisible Higgs decays and neutrino physics
1993
Abstract A wide class of neutrino physics motivated models are characterized by the spontaneous violation of a global U(1) lepton number symmetry at or below the electroweak scale by an SU(2)⊗U(1) singlet vacuum expectation value 〈 σ 〉 ≲ O(1) TeV. In all these models the main Higgs decay channel is likely to be “invisible”, e.g. h → JJ, where J denotes the associated weakly interacting pseudoscalar Goldstone boson — the majoron. This leads to events with large missing energy that could be observable at LEP and affect the Higgs mass bounds obtained, as well as lead to novel ways to search for Higgs bosons and high-energy supercolliders such as the LHC/SSC.
Radiative Corrections to Scalar Masses and Mixing in a Scale Invariant Two Higgs Doublet Model
2012
We study the Higgs-boson mass spectrum of a classical scale-invariant realization of the two-Higgs-doublet model (SI-2HDM). The classical scale symmetry of the theory is explicitly broken by quantum loop effects due to gauge interactions, Higgs self-couplings and top-quark Yukawa couplings. We determine the allowed parameter space compatible with perturbative unitarity and electroweak precision data. Taking into account the LEP and the recent LHC exclusion limits on a Standard-Model-like Higgs boson H_SM, we obtain rather strict constraints on the mass spectrum of the heavy Higgs sector of the SI-2HDM. In particular, if M_{H_SM} \sim 125 GeV, the SI-2HDM strongly favours scenarios, in which…
Higgs Sector of the Minimal Left-Right Symmetric Model
2001
We perform an exhaustive analysis of the most general Higgs sector of the minimal left-right symmetric model (MLRM). We find that the CP properties of the vacuum state are connected to the Higgs spectrum: if CP is broken spontaneously, the MLRM does not approach the Standard Model in the limit of a decoupling left-right symmetry breaking scale. Depending on the size of the CP phases scenarios with extra non-decoupling flavor-violating doublet Higgses or very light SU(2) triplet Higgses emerge, both of which are ruled out by phenomenology. For zero CP phases the non-standard Higgses decouple only if a very unnatural fine-tuning condition is fulfilled. We also discuss generalizations to a non…
Search for neutral Higgs bosons from supersymmetry in Z decays
1990
The light scalar Higgs boson h and the pseudoscalar Higgs boson A of the minimal supersymmetric standard model have been searched for in the processes e+e−→hff and e+e−→hA using data collected by ALEPH at the LEP e+e− collider, with center of mass energies at and near the Z peak. Using a variety of signatures adapted to various mass ranges for h and A, we have excluded a large domain in the parameter space. For large values of ν2ν1, the ratio of the vacuum expectation values of the two Higgs fields, the whole range from 0 to 38.8 GeV is excluded for Mh and MA at 95% CL.