4,678 research outputs found

    Matter parity as the origin of scalar Dark Matter

    Full text link
    We extend the concept of matter parity PM=(−1)3(B−L)P_M=(-1)^{3(B-L)} to non-supersymmetric theories and argue that PMP_M is the natural explanation to the existence of Dark Matter of the Universe. We show that the non-supersymmetric Dark Matter must be contained in scalar 16 representation(s) of SO(10),SO(10), thus the unique low energy Dark Matter candidates are PMP_M-odd complex scalar singlet(s) SS and inert scalar doublet(s) H2.H_2. We have calculated the thermal relic Dark Matter abundance of the model and shown that its minimal form may be testable at LHC via the SM Higgs boson decays H1→DMDM.H_1\to DM DM. The PAMELA anomaly can be explained with the decays DM→νlWDM\to \nu l W induced via seesaw-like operator which is additionally suppressed by Planck scale. Because the SM fermions are odd under matter parity too, the DM sector is just our scalar relative.Comment: The origin of scalar DM is emphasized, version accepted by PR

    Implications of the 125 GeV Higgs boson for scalar dark matter and for the CMSSM phenomenology

    Full text link
    We study phenomenological implications of the ATLAS and CMS hint of a 125±1125\pm 1 GeV Higgs boson for the singlet, and singlet plus doublet non-supersymmetric dark matter models, and for the phenomenology of the CMSSM. We show that in scalar dark matter models the vacuum stability bound on Higgs boson mass is lower than in the standard model and the 125 GeV Higgs boson is consistent with the models being valid up the GUT or Planck scale. We perform a detailed study of the full CMSSM parameter space keeping the Higgs boson mass fixed to 125±1125\pm 1 GeV, and study in detail the freeze-out processes that imply the observed amount of dark matter. After imposing all phenomenological constraints except for the muon (g−2)μ,(g-2)_\mu, we show that the CMSSM parameter space is divided into well separated regions with distinctive but in general heavy sparticle mass spectra. Imposing the (g−2)μ(g-2)_\mu constraint introduces severe tension between the high SUSY scale and the experimental measurements -- only the slepton co-annihilation region survives with potentially testable sparticle masses at the LHC. In the latter case the spin-independent DM-nucleon scattering cross section is predicted to be below detectable limit at the XENON100 but might be of measurable magnitude in the general case of light dark matter with large bino-higgsino mixing and unobservably large scalar masses.Comment: 17 pages, 7 figures. v3: same as published versio

    Long-lived charged Higgs at LHC as a probe of scalar Dark Matter

    Full text link
    We study inert charged Higgs boson H±H^\pm production and decays at LHC experiments in the context of constrained scalar dark matter model (CSDMM). In the CSDMM the inert doublet and singlet scalar's mass spectrum is predicted from the GUT scale initial conditions via RGE evolution. We compute the cross sections of processes pp→H+H−, H±Si0pp\to H^+H^-,\, H^\pm S_i^0 at the LHC and show that for light H±H^\pm the first one is dominated by top quark mediated 1-loop diagram with Higgs boson in s-channel. In a significant fraction of the parameter space H±H^\pm are long-lived because their decays to predominantly singlet scalar dark matter (DM) and next-to-lightest (NL) scalar, H±→SDM, NLff′,H^\pm\to S_{\text{DM, NL}} ff', are suppressed by the small singlet-doublet mixing angle and by the moderate mass difference ΔM=MH+−MDM. \Delta M=M_{H^+}-M_{\text{DM}} . The experimentally measurable displaced vertex in H±H^\pm decays to leptons and/or jets and missing energy allows one to discover the H+H−H^+H^- signal over the huge W+W−W^+W^- background. We propose benchmark points for studies of this scenario at the LHC. If, however, H±H^\pm are short-lived, the subsequent decays SNL→SDMffˉS_{\text{NL}}\to S_{\text{DM}} f\bar f necessarily produce additional displaced vertices that allow to reconstruct the full H±H^\pm decay chain.Comment: 15 pages, 5 figure

    Dark Matter as the signal of Grand Unification

    Full text link
    We argue that the existence of Dark Matter (DM) is a possible consequence of GUT symmetry breaking. In GUTs like SO(10), discrete Z_2 matter parity (-1)^{3(B-L)} survives despite of broken B-L, and group theory uniquely determines that the only possible Z_2-odd matter multiplets belong to representation 16. We construct the minimal non-SUSY SO(10) model containing one scalar 16 for DM and study its predictions below M_{G}. We find that EWSB occurs radiatively due to DM couplings to the SM Higgs boson. For thermal relic DM the mass range M_{DM}\sim (0.1-1) TeV is predicted by model perturbativity up to M_{G}. For M_{DM}\sim (1) TeV to explain the observed cosmic ray anomalies with DM decays, there exists a lower bound on the spin-independent direct detection cross section within the reach of planned experiments.Comment: DM direct detection cross section is corrected by adding s-quark contribution which turned out to be the dominant one. The prediction is just below the present CDMS and XENON10 bound. Extended version, RGE-s included, new references adde

    Effective Dark Matter Model: Relic density, CDMS II, Fermi LAT and LHC

    Full text link
    The Cryogenic Dark Matter Search recently announced the observation of two signal events with a 77% confidence level. Although statistically inconclusive, it is nevertheless suggestive. In this work we present a model-independent analysis on the implication of a positive signal in dark matter scattering off nuclei. Assuming the interaction between (scalar, fermion or vector) dark matter and the standard model induced by unknown new physics at the scale Λ\Lambda, we examine various dimension-6 tree-level induced operators and constrain them using the current experimental data, e.g. the WMAP data of the relic abundance, CDMS II direct detection of the spin-independent scattering, and indirect detection data (Fermi LAT cosmic gamma-ray), etc. Finally, the LHC reach is also explored

    Resilience of the Spectral Standard Model

    Get PDF
    We show that the inconsistency between the spectral Standard Model and the experimental value of the Higgs mass is resolved by the presence of a real scalar field strongly coupled to the Higgs field. This scalar field was already present in the spectral model and we wrongly neglected it in our previous computations. It was shown recently by several authors, independently of the spectral approach, that such a strongly coupled scalar field stabilizes the Standard Model up to unification scale in spite of the low value of the Higgs mass. In this letter we show that the noncommutative neutral singlet modifies substantially the RG analysis, invalidates our previous prediction of Higgs mass in the range 160--180 Gev, and restores the consistency of the noncommutative geometric model with the low Higgs mass.Comment: 13 pages, more contours added to Higgs mass plot, one reference adde

    Higgs and Dark Matter Hints of an Oasis in the Desert

    Get PDF
    Recent LHC results suggest a standard model (SM)-like Higgs boson in the vicinity of 125 GeV with no clear indications yet of physics beyond the SM. At the same time, the SM is incomplete, since additional dynamics are required to accommodate cosmological dark matter (DM). In this paper we show that interactions between weak scale DM and the Higgs which are strong enough to yield a thermal relic abundance consistent with observation can easily destabilize the electroweak vacuum or drive the theory into a non-perturbative regime at a low scale. As a consequence, new physics--beyond the DM itself--must enter at a cutoff well below the Planck scale and in some cases as low as O(10 - 1000 TeV), a range relevant to indirect probes of flavor and CP violation. In addition, this cutoff is correlated with the DM mass and scattering cross-section in a parameter space which will be probed experimentally in the near term. Specifically, we consider the SM plus additional spin 0 or 1/2 states with singlet, triplet, or doublet electroweak quantum numbers and quartic or Yukawa couplings to the Higgs boson. We derive explicit expressions for the full two-loop RGEs and one-loop threshold corrections for these theories.Comment: 29 pages, 13 figure
    • …
    corecore