Update of the direct detection of dark matter and the role of the nuclear spin (original) (raw)
Related papers
Direct detection of supersymmetric dark matter and the role of the target nucleus spin
Physical Review D, 1994
We investigate the role of nuclear spin in elastic scattering of Dark Matter (DM) neutralinos from nuclei in the framework of the Minimal SUSY standard model (MSSM). The relative contribution of spindependent axial-vector and spin-independent scalar interactions to the event rate in a DM detector has been analyzed for various nuclei. Within general assumptions about the nuclear and nucleon structure we find that for nuclei with atomic weights A > 50 the spin-independent part of the event rate R si is larger than the spin-dependent one R sd in the domain of the MSSM parameter space allowed by the known experimental data and where the additional constraint for the total event rate R = R sd + R si > 0.01 is satisfied. The latter reflects realistic sensitivities of present and near future DM detectors. Therefore we expect equal chances for discovering the DM event either with spin-zero or with spin-non-zero isotopes if their atomic weights are A 1 ∼ A 2 > 50.
Direct detection of dark matter in supersymmetric models
Journal of Cosmology and …, 2003
Abstract. We evaluate neutralino-nucleon scattering rates in several well-motivated supersymmetric models, and compare against constraints on the neutralino relic density, as well as the muon anomalous magnetic moment . In the mSUGRA model, the indirect constraints favour the ...
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
Update on the Direct Detection of Supersymmetric Dark Matter
Physical Review D, 2005
We compare updated predictions for the elastic scattering of supersymmetric neutralino dark matter with the improved experimental upper limit recently published by CDMS II. We take into account the possibility that the π-nucleon Σ term may be somewhat larger than was previously considered plausible, as may be supported by the masses of exotic baryons reported recently. We also incorporate the new central value of m t , which affects indirectly constraints on the supersymmetric parameter space, for example via calculations of the relic density. Even if a large value of Σ is assumed, the CDMS II data currently exclude only small parts of the parameter space in the constrained MSSM (CMSSM) with universal soft supersymmetry-breaking Higgs, squark and slepton masses. None of the previously-proposed CMSSM benchmark scenarios is excluded for any value of Σ, and the CDMS II data do not impinge on the domains of the CMSSM parameter space favoured at the 90% confidence level in a recent likelihood analysis. However, some models with non-universal Higgs, squark and slepton masses and neutralino masses < ∼ 700 GeV are excluded by the CDMS II data.
2008
We present brief synopses of supersymmetric models where either the neutralino composition or its mass is adjusted so that thermal relic neutralinos from the Big Bang saturate the measured abundance of cold dark matter in the universe. We first review minimal supergravity (mSUGRA), and then examine its various one-parameter extensions where we relax the assumed universality of the soft supersymmetry breaking parameters. Our goal is to correlate relic-density-allowed parameter choices with expected phenomena in direct, indirect and collider dark matter search experiments. For every non-universal model, we first provide plots to facilitate the selection of ``dark-matter allowed'' parameter space points, and then present salient features of each model with respect to searches at Tevatron, LHC and ILC and also direct and indirect dark matter searches. We present benchmark scenarios that allow one to compare and contrast the non-universal models with one another and with the para...
Journal of Cosmology and Astroparticle Physics, 2016
In this work we show how the inclusion of dark matter (DM) direct detection upper bounds in a theoretically consistent manner can affect the allowed parameter space of a DM model. Traditionally, the limits from DM direct detection experiments on the elastic scattering cross section of DM particles as a function of their mass are extracted under simplifying assumptions. Relaxing the assumptions related to the DM particle nature, such as the neutron to proton ratio of the interactions, or the possibility of having similar contributions from the spin independent (SI) and spin dependent (SD) interactions can vary significantly the upper limits. Furthermore, it is known that astrophysical and nuclear uncertainties can also affect the upper bounds. To exemplify the impact of properly including all these factors, we have analysed two well motivated and popular DM scenarios: neutralinos in the NMSSM and a Z ′ portal with Dirac DM. We have found that the allowed parameter space of these models is subject to important variations when one includes both the SI and SD interactions at the same time, realistic neutron to proton ratios, as well as using different self-consistent speed distributions corresponding to popular DM halo density profiles, and distinct SD structure functions. Finally, we provide all the necessary information to include the upper bounds of SuperCDMS and LUX taking into account all these subtleties in the investigation of any particle physics model. The data for each experiment and example codes are available at this site http://goo.gl/1CDFYi, and their use is detailed in the appendices of this work.
Light dark matter in the NMSSM: upper bounds on direct detection cross sections
Journal of High Energy Physics, 2010
In the Next-to-Minimal Supersymmetric Standard Model, a bino-like LSP can be as light as a few GeV and satisfy WMAP constraints on the dark matter relic density in the presence of a light CP-odd Higgs scalar. We study upper bounds on the direct detection cross sections for such a light LSP in the mass range 2 − 20 GeV in the NMSSM, respecting all constraints from B-physics and LEP. The OPAL constraints on e + e − → χ 0 1 χ 0 i (i > 1) play an important rôle and are discussed in some detail. The resulting upper bounds on the spin-independent and spin-dependent nucleon cross sections are ∼ 10 −42 cm 2 and ∼ 4 × 10 −40 cm 2 , respectively. Hence the upper bound on the spin-independent cross section is below the DAMA and CoGeNT regions, but could be compatible with the two events observed by CDMS-II.
Indirect, direct and collider detection of neutralino dark matter in the minimal supergravity model
Journal of Cosmology …, 2004
We examine the prospects for supersymmetry discovery in the minimal supergravity (mSUGRA) model via indirect detection of neutralino dark matter. We investigate rates for muon detection in neutrino telescopes, and detection of photons, positrons and anti-protons by balloon and space based experiments. We compare the discovery reach in these channels with the reach for direct detection of dark matter, and also with the reach of collider experiments such as Fermilab Tevatron, CERN LHC and a √ s = 0.5 − 1 TeV linear e + e − collider. We pay particular attention to regions of model parameter space in accord with recent WMAP results on the dark matter density of the universe. We find that 3rd generation direct dark matter detection experiments should be able to cover the entire WMAP allowed portion of the hyperbolic branch/focus point (HB/FP) region of parameter space, while the IceCube neutrino telescope can cover almost all this region. This is in contrast to the case of the CERN LHC or a linear e + e − collider, where only a fraction of the HB/FP region can be accessed. In addition, we show that detection of γs, e + s andps should occur in much of the HB/FP region, as well as in the low m 1/2 portion of the A annihilation funnel, and will be complementary to searches via colliders in these regions.
Theoretical expectations for dark matter detection at the LHC
I present an overview of theoretical expectations for detection of dark matter (DM) at the LHC, concentrating entirely on supersymmetric candidates. En route, I present a unified theory which explains dark matter signals at indirect and direct detection experiments. While direct DM detection is likely impossible at LHC, detection of SUSY matter states is robust, where LHC with \sqrt{s}=7 TeV and 1fb^{-1} can access m(gluino) 1 TeV for m(squark) m(gluino), and m(gluino) 640 GeV for m(squark)>> m(gluino). Models with well-tempered neutralinos will soon be tested by Xenon-100/LUX, and should provide a distinctive mass edge at LHC in the m(l+l-) distribution. In the case of SUSY, neutralino dark matter now seems highly disfavored by both the magnitude of the dark matter density, and also the gravitino problem. Alternatively, the PQMSSM yields a solution to the strong CP problem, provides all the benefits of SUSY, and solves several cosmological problems. Predictions for SUSY parti...
Journal of Cosmology and Astroparticle Physics, 2007
The viability of the lightest neutralino as a dark matter candidate in the next-to-minimal supersymmetric standard model is analysed. We carry out a thorough analysis of the parameter space, taking into account accelerator constraints as well as bounds on low-energy observables, such as the muon anomalous magnetic moment and rare K and B meson decays. The neutralino relic density is also evaluated and consistency with present bounds imposed. Finally, the neutralino direct detection cross section is calculated in the allowed regions of the parameter space and compared to the sensitivities of present and projected dark matter experiments. Regions of the parameter space are found where experimental constraints are fulfilled, the lightest neutralino has the correct relic abundance and its detection cross section is within the reach of dark matter detectors. This is possible in the presence of very light singlet-like Higgses and when the neutralino is either light enough so that some annihilation channels are kinematically forbidden, or has a large singlino component.