Correlation between direct dark matter detection andBr(Bs→μμ)with a large phase ofBs−B¯smixing (original) (raw)
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Physical Review D, 2009
We combine the analyses for flavor changing neutral current processes and dark matter solutions in minimal-type supersymmetric grand unified theory (GUT) models, SO(10) and SU(5), with a large B s-B s mixing phase and large tan β. For large tan β, the double penguin diagram dominates the SUSY contribution to the B s-B s mixing amplitude. Also, the Br(B s → µµ) constraint becomes important as it grows as tan 6 β, although it can still be suppressed by large pseudoscalar Higgs mass m A. We investigate the correlation between B s → µµ and the dark matter direct detection cross-section through their dependence on m A. In the minimal-type of SU(5) with type I seesaw, the large mixing in neutrino Dirac couplings results in large lepton flavor violating decay process τ → µγ, which in turn sets upper bound on m A. In the SO(10) case, the large mixing can be chosen to be in the Majorana couplings instead, and the constraint from Br(τ → µγ) can be avoided. The heavy Higgs funnel region turns out to be an interesting possibility in both cases and the direct dark matter detection should be possible in the near future in these scenarios.
Physical Review D, 2003
We calculate dark matter scattering rates in the minimal supersymmetric extension of the Standard Model (MSSM), allowing the soft supersymmetry-breaking masses of the Higgs multiplets, m 1,2 , to be non-universal (NUHM). Compared with the constrained MSSM (CMSSM) in which m 1,2 are required to be equal to the soft supersymmetry-breaking masses m 0 of the squark and slepton masses, we find that the elastic scattering cross sections may be up to two orders of magnitude larger than values in the CMSSM for similar LSP masses. We find the following preferred ranges for the spin-independent cross section: 10 −6 pb > ∼ σ SI > ∼ 10 −10 pb, and for the spin-dependent cross section: 10 −3 pb > ∼ σ SD , with the lower bound on σ SI dependent on using the putative constraint from the muon anomalous magnetic moment. We stress the importance of incorporating accelerator and dark matter constraints in restricting the NUHM parameter space, and also of requiring that no undesirable vacuum appear below the GUT scale. In particular, values of the spin-independent cross section another order of magnitude larger would appear to be allowed, for small tan β, if the GUT vacuum stability requirement were relaxed, and much lower cross-section values would be permitted if the muon anomalous magnetic moment constraint were dropped.
Dark matter allowed scenarios for Yukawa-unified SO(10) SUSY GUTs
Journal of High Energy Physics, 2008
Simple supersymmetric grand unified models based on the gauge group SO(10) require-in addition to gauge and matter unification-the unification of t-b-τ Yukawa couplings. Owing to sparticle contributions to fermion self-energy diagrams, the Yukawa unification however only occurs for very special values of the soft SUSY breaking parameters. We perform a search using a Markov Chain Monte Carlo (MCMC) technique to investigate model parameters and sparticle mass spectra which occur in Yukawa-unified SUSY models, where we also require the relic density of neutralino dark matter to saturate the WMAPmeasured abundance. For Yukawa unified models with µ > 0, the spectrum is characterizd by three mass scales: first and second generation scalars in the multi-TeV range, third generation scalars in the TeV range, and gauginos in the ∼ 100 GeV range. Most solutions give far too high a relic abundance of neutralino dark matter. The dark matter discrepancy can be rectified by i). allowing for neutralino decay to axino plus photon, ii). imposing gaugino mass non-universality or iii). imposing generational non-universality. In addition, the MCMC approach finds a compromise solution where scalar masses are not too heavy, and where neutralino annihilation occurs via the light Higgs h resonance. By imposing weak scale Higgs soft term boundary conditions, we are also able to generate low µ, m A solutions with neutralino annihilation via a light A resonance, though these solutions seem to be excluded by CDF/D0 measurements of the B s → µ + µ − branching fraction. Based on the dual requirements of Yukawa coupling unification and dark matter relic density, we predict new physics signals at the LHC from pair production of 350-450 GeV gluinos. The events are characterized by very high b-jet multiplicity and a dilepton mass edge around mχ0 2 − mχ0 1 ∼ 50-75 GeV.
Cold dark matter detection in SUSY models at large /tanbeta
Physics Letters B, 2001
We study the direct detection rate for SUSY cold dark matter (CDM) predicted by the minimal supersymmetric standard model with universal boundary conditions and large values for /tanβ. The relic abundance of the lightest supersymmetric particle (LSP), assumed to be approximately a bino, is obtained by including its coannihilations with the next-to-lightest supersymmetric particle (NLSP), which is the lightest s-tau. The cosmological constraint on this quantity severely limits the allowed SUSY parameter space, especially in the case the CP-even Higgs has mass of around 114 GeV. We find that for large /tanβ it is possible to find a subsection of the allowed parameter space, which yields detectable rates in the currently planned experiments.
Cold dark matter detection in SUSY models at large tanβ
Physics Letters B, 2001
We study the direct detection rate for SUSY cold dark matter (CDM) predicted by the minimal supersymmetric standard model with universal boundary conditions and large values for tanβ. The relic abundance of the lightest supersymmetric particle (LSP), assumed to be approximately a bino, is obtained by including its coannihilations with the next-to-lightest supersymmetric particle (NLSP), which is the lightest s-tau. The cosmological constraint on this quantity severely limits the allowed SUSY parameter space, especially in the case the CP-even Higgs has mass of around 114 GeV. We find that for large tanβ it is possible to find a subsection of the allowed parameter space, which yields detectable rates in the currently planned experiments.
Physics of Atomic Nuclei, 2002
Direct detection experiments for neutralino dark matter in the Milky Way are examined within the framework of SUGRA models with R-parity invariance and grand unification at the GUT scale, M G. Models of this type apply to a large number of phenomena, and all existing bounds on the SUSY parameter space due to current experimental constraints are included. For models with universal soft breaking at M G (mSUGRA), the Higgs mass and b → sγ constraints imply that the gaugino mass, m 1/2 , obeys m 1/2 >(300-400)GeV putting most of the parameter space in the co-annihilation domain where there is a relatively narrow band in the m 0 − m 1/2 plane. For µ > 0 we find that the neutralino-proton cross section > ∼ 10 −10 pb for m 1/2 < 1 TeV, making almost all of this parameter space accessible to future planned detectors. For µ < 0, however, there will be large regions of parameter space with cross sections < 10 −12 pb, and hence unaccessible experimentally. If, however, the muon magnetic moment anomaly is confirmed, then µ > 0 and m 1/2 < ∼ 800 GeV. Models with non-universal soft breaking in the third generation and Higgs sector can allow for new effects arising from additional early universe annihilation through the Z-channel pole. Here cross sections that will be accessible in the near future to the next generation of detectors can arise, and can even rise to the large values implied by the DAMA data. Thus dark matter detectors have the possibility of studying the the post-GUT physics that control the patterns of soft breaking.
Bs→μ+μ− in supersymmetric grand unified theories
Physics Letters B, 2011
We investigate the recent CDF measurement of the Br(B s → µ + µ −) which shows excess over the Standard Model. We consider minimal supergravity motivated models (mSUGRA)/CMSSM and grand unified models, SU(5) and SO(10). In the grand unified models, the neutrino mixings provide an additional source of squark flavor violation through the quark-lepton unification. In the context of minimal SU(5) model, we find that the new CDF measurement has imposed a lower bound on the branching ratio of τ → µγ for a large CP phase in the B s-B s mixing. Recall that there have been indication for a large CP phase in B s mixing from B s → J/ψφ (Tevatron and LHCb) and dimuon asymmetry (D0). We also predict Br(τ → µη) for the possible range of values of Br(τ → µγ).
Physical Review D, 2010
We re-examine the prospects for the detection of Higgs mediated lepton flavor violation at LHC, at a photon collider and in τ decays such as τ → µη, τ → µγ. We allow for the presence of a large, model independent, source of lepton flavor violation in the slepton mass matrix in the τ − µ sector by the mass insertion approximation and constrain the parameter space using the τ LFV decays together with the B-mesons physics observables, the anomalous magnetic moment of the muon and the dark matter relic density. We further impose the exclusion limit on spin-independent neutralinonucleon scattering from CDMS and the CDF limits from direct search of the heavy neutral Higgs at the TEVATRON. We find rates probably too small to be observed at future experiments if models have to accommodate for the relic density measured by WMAP and explain the (g − 2)µ anomaly: better prospects are found if these two constraints are applied only as upper bounds. The spin-independent neutralino-nucleon cross section in the studied constrained parameter space is just below the present CDMS limit and the running XENON100 experiment will cover the region of the parameter space where the lightest neutralino has large gaugino-higgsino mixing.
Physical Review D, 2006
We explore the prospects for indirect detection of neutralino dark matter in supersymmetric models with an extended Higgs sector (NMSSM). We compute, for the first time, one-loop amplitudes for NMSSM neutralino pair annihilation into two photons and two gluons, and point out that extra diagrams (with respect to the MSSM), featuring a potentially light CP-odd Higgs boson exchange, can strongly enhance these radiative modes. Expected signals in neutrino telescopes due to the annihilation of relic neutralinos in the Sun and in the Earth are evaluated, as well as the prospects of detection of a neutralino annihilation signal in space-based gamma-ray, antiproton and positron search experiments, and at low-energy antideuteron searches. We find that in the low mass regime the signals from capture in the Earth are enhanced compared to the MSSM, and that NMSSM neutralinos have a remote possibility of affecting solar dynamics. Also, antimatter experiments are an excellent probe of galactic NMSSM dark matter. We also find enhanced two photon decay modes that make the possibility of the detection of a monochromatic gamma-ray line within the NMSSM more promising than in the MSSM. I. INTRODUCTION Numerous theoretical and phenomenological motivations exist for a Minimal Supersymmetric extension of the Standard Model (MSSM). At the same time one of the attractive by-products of low energy supersymmetry is the natural occurrence in the particle content of the theory of a stable weakly interacting massive particle, the lightest neutralino, which could be the microscopic constituent of the as yet unobserved galactic halo dark matter. Another strong motivation comes from the SM hierarchy problem, originating from the large fine-tuning required by the stability of the electroweak scale to radiative corrections, originating from the large number of orders of magnitude occurring between the GUT, or the Planck, scale, and the electroweak scale itself. Although very appealing, the MSSM has been challenged by various pieces of experimental information, and by some arguments of more theoretical nature. Among these, the LEP-II limit on the mass of the lightest CP-even Higgs [1], the constraints on the masses of supersymmetric (Susy) charged or colored particles from direct searches at LEP and at the Tevatron [2], and the so-called µ problem, i.e. the fundamental reason why the Susy Higgsino mass term µ appearing in the MSSM superpotential lies at some scale near the electroweak scale rather than at some much higher scale. The addition of a new gauge singlet chiral multiplet,Ŝ, to the particle content of the MSSM can provide an elegant solution to the mentioned µ problem of the MSSM [3]. The so-called Next to Minimal Supersymmetric Standard Model (NMSSM) [4] is an example of one such minimal extension that also alleviates the little fine tuning problem of the MSSM, arising from the non-detection of a neutral CP-even Higgs at LEP-II [1]. A further motivation to go beyond the MSSM comes from Electro-Weak Baryogenesis (EWB), i.e. the possibility that the baryon asymmetry of the Universe originated through electro-weak physics at the electro-weak phasetransition in the Early Universe. Although still a viable scenario within the MSSM [5], EWB generically requires the Higgs mass to be in the narrow mass range above the current LEP-II limits and below ≃ 120 GeV, a rather unnatural mass splitting between the right-handed and the left-handed stops (the first one required to lie below the top quark mass, and the other in the multi-TeV range), CP violation at levels sometimes at odds with electric dipole moment experimental results, and, generically, a very heavy sfermion sector [6]. In contrast, the NMSSM provides extra triscalar Higgs couplings which hugely facilitate the occurrence of a more strongly first-order EW phase transition, and extra CP violating sources, relaxing most of the above mentioned requirements in the context of the MSSM [7, 8]. One of the chief remaining cosmological issues associated with the NMSSM, the cosmological domain wall problem [9], caused by the discrete Z 3 symmetry of the NMSSM, can be circumvented by introducing non-renormalizable Planck-suppressed operators [10]. The Higgs sector of the NMSSM contains three CP-even and two CP-odd scalars, which are mixtures of MSSM-like Higgses and singlets. Also, the neutralino sector contains five mass-eigenstates, instead of the four in the MSSM, each of which has, in addition to the four MSSM components, a singlino component, the latter being the fermionic partner of the extra singlet scalars. The extended Higgs and neutralino sectors weaken the mass bounds for both the Higgs bosons and the neutralinos. Very light neutralinos and Higgs bosons, even in the few GeV range, are in fact not
Physical Review D, 2009
A non-universal scalar mass supergravity type of model is explored where the first two generation of scalars and the third generation of sleptons may be very massive. The lighter or vanishing third generation of squarks as well as Higgs scalars at the unification scale cause the radiative electroweak symmetry breaking constraint to be less prohibitive. Thus, both FCNC/CP-violation problems as well as the naturalness problem are within control. We identify a large slepton mass effect in the RGE of m 2 H D (for the down type of Higgs) that may turn the later negative at the electroweak scale even for a small tan β. A hyperbolic branch/focus point like effect is found for m 2 A that may result in very light Higgs spectra. The lightest stable particle is dominantly a bino that pair annihilates via Higgs exchange, giving rise to a WMAP satisfied relic density region for all tan β. Detection prospects of such LSPs in the upcoming dark matter experiments both of direct and indirect types (photon flux) are interesting. The Higgs bosons and the third generation of squarks are light in this scenario and these may be easily probed besides charginos and neutralinos in the early runs of LHC.