Lightest Neutralino Mass Research Articles

(g-2)μ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$(g-2)_\\mu $$\\end{document} and stau coannihilation: dark matter and collider analysis

Slepton coannihilation is one of the most promising scenarios that can bring the predicted Dark Matter (DM) abundance in the the Minimal Supersymmetric Standard Model (MSSM) into agreement with the experimental observation. In this scenario, the lightest supersymmetric particle (LSP), usually assumed to be the lightest neutralino, χ~10\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ ilde{\\chi }_{1}^0$$\\end{document} can serve as a Dark Matter (DM) candidate while the sleptons as the next-to-LSPs (NLSPs) lie close in mass. In our previous studies analyzing the electroweak sector of MSSM, a degeneracy between the three generations of sleptons was assumed for the sake of simplicity. In case of slepton coannihilation this directly links the smuons involved in the explanation for (g-2)μ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$(g-2)_\\mu $$\\end{document} to the coannihilating NLSPs required to explain the DM content of the universe. On the other hand, in well-motivated top-down models such degeneracy do not hold, and often the lighter stau turns out to be the NLSP at the electroweak (EW) scale, with the smuons (and selectrons) somewhat heavier. In this paper we analyze such a scenario at the EW scale assuming non-universal slepton masses where the first two generations of sleptons are taken to be mass-degenerate and heavier than the staus, enforcing stau coannihilation. We analyze the parameter space of the electroweak MSSM in the light of a variety of experimental data namely, the DM relic density and direct detection limits, LHC data and especially, the discrepancy between the experimental result for the anomalous magnetic moment of the muon, (g-2)μ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$(g-2)_\\mu $$\\end{document}, and its Standard Model (SM) prediction. We find an upper limit on the lightest neutralino mass, the lighter stau mass and the mass of the tau sneutrino of about ∼550GeV\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\sim 550 \\,\\, {\ extrm{GeV}}$$\\end{document}. In contrast to the scenario with full degeneracy among the three families of sleptons, the upper limit on the light smuon/selectron mass moves up by ∼200GeV\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\sim 200 \\,\\, {\ extrm{GeV}}$$\\end{document}. We analyze the DD prospects as well as the physics potential of the HL-LHC and a future high-energy e+e-\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$e^+e^-$$\\end{document} collider to investigate this scenario further. We find that the combination DD experiments and e+e-\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$e^+e^-$$\\end{document} collider searches with center of mass energies up to s∼1100GeV\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\sqrt{s} \\sim 1100 \\,\\, {\ extrm{GeV}}$$\\end{document} can fully cover this scenario.

Search for new phenomena in final states with two opposite-charge, same-flavor leptons, jets, and missing transverse momentum in pp collisions at sqrt{s}=13 TeV

Search results are presented for physics beyond the standard model in final states with two opposite-charge, same-flavor leptons, jets, and missing transverse momentum. The data sample corresponds to an integrated luminosity of 35.9 fb−1 of proton-proton collisions at sqrt{s}=13 TeV collected with the CMS detector at the LHC in 2016. The analysis uses the invariant mass of the lepton pair, searching for a kinematic edge or a resonant-like excess compatible with the Z boson mass. The search for a kinematic edge targets production of particles sensitive to the strong force, while the resonance search targets both strongly and electroweakly produced new physics. The observed yields are consistent with the expectations from the standard model, and the results are interpreted in the context of simplified models of supersymmetry. In a gauge mediated supersymmetry breaking (GMSB) model of gluino pair production with decay chains including Z bosons, gluino masses up to 1500–1770 GeV are excluded at the 95% confidence level depending on the lightest neutralino mass. In a model of electroweak chargino-neutralino production, chargino masses as high as 610 GeV are excluded when the lightest neutralino is massless. In GMSB models of electroweak neutralino-neutralino production, neutralino masses up to 500-650 GeV are excluded depending on the decay mode assumed. Finally, in a model with bottom squark pair production and decay chains resulting in a kinematic edge in the dilepton invariant mass distribution, bottom squark masses up to 980–1200 GeV are excluded depending on the mass of the next-to-lightest neutralino.

Combined search for electroweak production of charginos and neutralinos in proton-proton collisions at sqrt{s}=13 TeV

A statistical combination of several searches for the electroweak production of charginos and neutralinos is presented. All searches use proton-proton collision data at sqrt{s}=13 TeV, recorded with the CMS detector at the LHC in 2016 and corresponding to an integrated luminosity of 35.9 fb−1. In addition to the combination of previous searches, a targeted analysis requiring three or more charged leptons (electrons or muons) is presented, focusing on the challenging scenario in which the difference in mass between the two least massive neutralinos is approximately equal to the mass of the Z boson. The results are interpreted in simplified models of chargino-neutralino or neutralino pair production. For chargino-neutralino production, in the case when the lightest neutralino is massless, the combination yields an observed (expected) limit at the 95% confidence level on the chargino mass of up to 650 (570) GeV, improving upon the individual analysis limits by up to 40 GeV. If the mass difference between the two least massive neutralinos is approximately equal to the mass of the Z boson in the chargino-neutralino model, the targeted search requiring three or more leptons obtains observed and expected exclusion limits of around 225 GeV on the second neutralino mass and 125 GeV on the lightest neutralino mass, improving the observed limit by about 60 GeV in both masses compared to the previous CMS result. In the neutralino pair production model, the combined observed (expected) exclusion limit on the neutralino mass extends up to 650–750 (550–750) GeV, depending on the branching fraction assumed. This extends the observed exclusion achieved in the individual analyses by up to 200 GeV. The combined result additionally excludes some intermediate gaps in the mass coverage of the individual analyses.

Testing the light dark matter scenario of the MSSM at the LHC

In the light dark matter (DM) scenario of the MSSM, the DM relic density puts non-trivial requirements on the spectrum of supersymmetric particles. As a result, the direct search for multi-lepton signals at the LHC has great impact on the scenario. In this work, we concentrate on the searches for sleptons and electroweak-inos at the LHC, and investigate the constraints on the light DM scenario from the 8 TeV LHC data as well as the capability of the 14 TeV LHC to test the scenario. We first get the samples of the scenario by scanning the vast parameter space of the MSSM and considering some easily available constraints, such as those from the DM relic density, the LUX experiment and the Higgs searches at colliders. Then for the surviving samples, we simulate the $2l+E_T^{miss}$ signal from slepton pair production process and the $2l+E_T^{miss}$ and $3l+E_T^{miss}$ signals from chargino and neutralino associated production processes at both the 8 TeV LHC and the 14 TeV LHC. Our simulations indicate that the 8 TeV LHC has excluded a sizable portion of the samples, and the 14 TeV LHC can be even much more powerful in testing the scenario. For example, in case that no multi-lepton signals are observed at the 14 TeV LHC, most samples of the light DM scenario will be excluded, especially a lower limit on the lightest neutralino mass will be set at 42 GeV and 44 GeV with 30 $fb^{-1}$ and 100 $fb^{-1}$ data respectively, and this limit can be further pushed up to $55\ {\rm GeV}$ with 300 $fb^{-1}$ data.

Search for supersymmetry in events with soft leptons, low jet multiplicity, and missing transverse energy in proton–proton collisions at s=8 TeV

Results are presented from a search for supersymmetric particles in scenarios with a compressed mass spectrum. The data sample corresponds to 19.7 inverse femtobarns of proton-proton collisions recorded by the CMS experiment at sqrt(s) = 8 TeV. The search targets top squark pair production in scenarios with mass differences Delta m = m(top squark) - m(neutralino) below the W-boson mass and with top-squark decays in the four-body mode (top squark to b l nu neutralino), where the neutralino is assumed to be the lightest supersymmetric particle (LSP). The signature includes a high transverse momentum (pt) jet associated with initial-state radiation, one or two low-pt leptons, and significant missing transverse energy. The event yields observed in data are consistent with the expected background contributions from standard model processes. Limits are set on the cross section for top squark pair production as a function of the top squark and LSP masses. Assuming a 100% branching fraction for the four-body decay mode, top-squark masses below 316 GeV are excluded for Delta m = 25 GeV at 95% CL. The dilepton data are also interpreted under the assumption of chargino-neutralino production, with subsequent decays to sleptons or sneutrinos. Assuming a difference between the common lightest chargino/next lightest neutralino mass and the LSP mass of 20 GeV and a tau-enriched decay scenario, masses in the range m(chargino) < 307 GeV are excluded at 95% CL.

PAMELA excess from neutralino annihilation in the NMSSM

We examine whether the cosmic ray positron excess observed by PAMELA can be explained by neutralino annihilation in the next-to-minimal supersymmetric standard model (NMSSM). The main dark matter annihilation products are the lightest $CP$-even scalar ${h}_{1}$ plus the lightest $CP$-odd scalar ${a}_{1}$, with the ${a}_{1}$ decaying into two muons. The energetic positrons needed to explain PAMELA are thus obtained in the NMSSM simply from kinematics. The required large annihilation cross section is obtained from an $s$-channel resonance with the heavier $CP$-odd scalar ${a}_{2}$. Various experiments constrain the PAMELA-favored NMSSM parameter space, including collider searches for a light ${a}_{1}$. These constraints point to a unique corner of the NMSSM parameter space, having a lightest neutralino mass around 160 GeV and a very light pseudoscalar mass less than a GeV. A simple parametrized formula for the charge-dependent solar modulation effects reconciles the discrepancy between the PAMELA data and the estimated background at lower energies. We also discuss the electron and gamma-ray spectra from the Fermi LAT observations, and point out the discrepancy between the NMSSM predictions and Fermi LAT preliminary results and possible resolution. An NMSSM explanation of PAMELA makes three striking and uniquely correlated predictions: the rise in the PAMELA positron spectrum will turn over at around 70 GeV, the dark matter particle mass is less than the top quark mass, and a light sub-GeV pseudoscalar will be discovered at colliders.

Complementarity of gamma-ray and CERN LHC searches for neutralino dark matter in the focus point region

We study the complementarity between the indirect detection of dark matter with $\ensuremath{\gamma}$-rays in H.E.S.S. and the supersymmetry searches with ATLAS at the Large Hadron Collider (LHC) in the focus point region within the mSUGRA framework. The sensitivity of the central telescope of the H.E.S.S. II experiment with an energy threshold of $\ensuremath{\sim}20\text{ }\text{ }\mathrm{GeV}$ is investigated. We show that the detection of $\ensuremath{\gamma}$-ray fluxes of $\mathcal{O}({10}^{\ensuremath{-}12})\text{ }\text{ }{\mathrm{cm}}^{\ensuremath{-}2}\text{ }{\mathrm{s}}^{\ensuremath{-}1}$ with H.E.S.S. II covers a substantial part of the focus point region which may be more difficult for LHC experiments. Despite the presence of multi-TeV scalars, we show that LHC will be sensitive to a complementary part of this region through three-body next-to-lightest supersymmetric particle leptonic decays. This interesting complementarity between H.E.S.S. II and LHC searches is further highlighted in terms of the gluino mass and the two lightest neutralino mass difference.

Theoretical upper bound on the mass of the LSP in the MNSSM

We study the neutralino sector of the Minimal Non-minimal Supersymmetric Standard Model (MNSSM) where the μ problem of the Minimal Supersymmetric Standard Model (MSSM) is solved without accompanying problems related with the appearance of domain walls. In the MNSSM as in the MSSM the lightest neutralino can be the absolutely stable lightest supersymmetric particle (LSP) providing a good candidate for the cold dark matter component of the Universe. In contrast with the MSSM the allowed range of the mass of the lightest neutralino in the MNSSM is limited. We establish the theoretical upper bound on the lightest neutralino mass in the framework of this model and obtain an approximate solution for this mass.

SUSY-GUTs, SUSY-Seesaw and the neutralino dark matter

We will consider a SUSY-SU(5) with one right-handed neutrino with a large top like Yukawa coupling. Assuming universal soft masses at high scale we compute the low-energy spectrum and subsequently the neutralino LSP relic density taking also into consideration SU(5) as well as the see-saw running effects above the gauge coupling unification scale. We found that there exists no viable region in parameter space for tan β 35. The coannihilation process starts becoming efficient for tan β 35−40. However, this process is significantly constrained by the limited range in which the stau is lighter than the neutralino. In fact, for a given tan β we find that there exists an upper bound on the lightest neutralino mass (Mχ10) in this region. The A-pole funnel region appears at very large tan β 45−50, while the focus-point region does not make an appearance till large (m0, M1/2), namely a few TeV. Large A0 terms at high scale can lead to extended regions consistent with WMAP constraints and remove the upper bounds in the stau coannihilation regions.

QCD correction to neutralino annihilation process and dark matter density in supersymmetric models

We calculate QCD correction to the neutralino annihilation cross section into quark anti-quark final state and discuss its implications to the calculation of neutralino relic density. We see that the QCD correction enhances the pair-annihilation cross section by O(10 %) when final-state quarks are non-relativistic. Consequently, when the lightest neutralinos dominantly annihilate into a t\bar{t} pair, the relic density of the lightest neutralino is significantly affected by the QCD correction, in particular when the lightest-neutralino mass is close to the top-quark mass.

Muon anomalous magnetic moment in a supersymmetric [formula omitted] model

We study the muon anomalous magnetic moment aμ=(gμ−2)/2 in a supersymmetric U(1)′ model. The neutralino sector has extra components from the superpartners of the U(1)′ gauge boson and the extra Higgs singlets that break the U(1)′ symmetry. The theoretical maximum bound on the lightest neutralino mass is much smaller than that of the Minimal Supersymmetric Standard Model (MSSM) because of the mixing pattern of the extra components. In a U(1)′ model where the U(1)′ symmetry is broken by a secluded sector (the S-model), tanβ is required to be ≲3 to have realistic electroweak symmetry breaking. These facts suggest that the aμ prediction may be meaningfully different from that of the MSSM. We evaluate and compare the muon anomalous magnetic moment in this model and the MSSM and discuss the constraints on tanβ and relevant soft breaking terms. There are regions of the parameter space that can explain the experimental deviation of aμ from the Standard Model calculation and yield an acceptable cold dark matter relic density without conflict with collider experimental constraints.

Neutralino relic density in a supersymmetric [formula omitted] model

We study properties of the lightest neutralino (χ0) and calculate its cosmological relic density in a supersymmetric U(1)′ model with a secluded U(1)′ breaking sector (the S-model). The lightest neutralino mass is smaller than in the minimal supersymmetric standard model; for instance, mχ0≲100 GeV in the limit that the U(1)′ gaugino mass is large compared to the electroweak scale. We find that the Zχ0χ0 coupling can be enhanced due to the singlino components in the extended neutralino sector. Neutralino annihilation through the Z-resonance then reproduces the measured cold dark matter density over broad regions of the model parameter space.

Electroweak baryogenesis and dark matter in a minimal extension of the MSSM

We examine the possibility of electroweak baryogenesis and dark matter in the nMSSM, a minimal extension of the MSSM with a singlet field. This extension avoids the usual domain wall problem of the NMSSM, and also appears as the low energy theory in models of dynamical electroweak symmetry breaking with a so-called fat-Higgs boson. We demonstrate that a strong, first order electroweak phase transition, necessary for electroweak baryogenesis, may arise in regions of parameter space where the lightest neutralino provides an acceptable dark matter candidate. We investigate the parameter space in which these two properties are fulfilled and discuss the resulting phenomenology. In particular, we show that there are always two light CP-even and one light CP-odd Higgs bosons with masses smaller than about 250 GeV. Moreover, in order to obtain a realistic relic density, the lightest neutralino mass tends to be smaller than $M_Z/2$, in which case the lightest Higgs boson decays predominantly into neutralinos.

Search for chargino and neutralino production at

A search for charginos and neutralinos, predicted by supersymmetric theories, has been performed using a data sample of 57 pb $^{-1}$ at centre-of-mass energies of 181–184 GeV taken with the OPAL detector at LEP. No evidence for chargino or neutralino production has been found. Upper limits on chargino and neutralino pair production ( $\tilde\chi^+_1 \tilde\chi^-_1$ , $\tilde\chi^0_1 \tilde\chi^0_2$ ) cross-sections are obtained as a function of the chargino mass ( $m_{\tilde\chi^\pm_1}$ ), the lightest neutralino mass ( $m_{\tilde\chi^0_1}$ ) and the second lightest neutralino mass ( $m_{\tilde\chi^0_2}$ ). For large chargino masses the limits have been improved with respect to the previous analyses at lower centre-of-mass energies. Exclusion regions at 95% confidence level (C.L.) of parameters of the Constrained Minimal Supersymmetric Standard Model are determined for the case of a large universal scalar mass, $m_0$ , implying heavy scalar fermions, and for the case of a small $m_0$ resulting in light scalar fermions and giving the worst-case limits. Within this framework and for $m_{\tilde\chi^\pm_1} - m_{\tilde\chi^0_1} \geq 5$ GeV the 95% C.L. lower limits on $m_{\tilde\chi^\pm_1}$ for $m_0=500$ GeV are 90.0 and 90.2 GeV for $\tan \beta = 1.5$ and 35 respectively. These limits for all $m_0$ (the worst-case) are 69.1 and 65.2 GeV for $\tan \beta = 1.5$ and 35 respectively. Exclusion regions are also presented for neutralino masses, including an absolute lower limit at 95% C.L. for the mass of the lightest neutralino of 30.1 GeV for $m_0 = 500$ GeV (24.2 GeV for all $m_0$ ), with implications for experimental searches for the lightest neutralino as a dark matter candidate.

Limits on SUSY particle spectra from proton stability and dark matter constraints

It is shown that the combined constraints on the amount of cold dark matter and of proton stability produce a stringent upper limit on the gluino mass m g ̃ (and hence on the lightest neutralino mass m χ 1 0 ≃m g ̃ /7 for a large class of gravity mediated supergravity unified models. One finds that for the minimal SU(5) model current data (Kamiokande) restricts m g ̃ ≤400 GeV for a scalar soft breaking mass m 0≤1 TeV. Expected future data from Super Kamiokande and ICARUS will be sensitive to the entire range of gluino mass for m 0≤1 TeV, and be sensitive to the region m g ̃ ≥500 GeV for m 0≤5 TeV. Effects of quark mass textures are studied and one finds that the bound m g ̃ ≤500 GeV holds when the experimental proton lifetime for the p→ ν ̄ K + mode becomes ≥5×10 32 yr. Implications of these results for a test of these models at the Tevatron and at the LHC are discussed. The effects of non-universal soft breaking in the Higgs and the third generation squark sectors are also examined, and it is found that the proton lifetime is sensitive to these non-universal effects. The current data already eliminates some regions of non-universalities. The constraints of proton stability on the direct detection of dark matter are seen to reduce the maximum event rates by as much as a factor of 10 3.

Search for chargino and neutralino production at $\sqrt{s} = 170$ and 172 GeV at LEP

A search for charginos and neutralinos, predicted by supersymmetric theories, is performed using a data sample of 182.1 pb-1 taken at a centre-of-mass energy of 189 GeV with the OPAL detector at LEP. No evidence for chargino or neutralino production is found. Upper limits on chargino and neutralino pair production (X1+X1-, X10X20) cross-sections are obtained as a function of the chargino mass (mX1±), the lightest neutralino mass (mX10) and the second lightest neutralino mass (mX20). Within the Constrained Minimal Supersymmetric Standard Model framework, and for mX1± - mX10 ≥ 5 GeV, the 95% confidence level lower limits on mX1± are 93.6 GeV for tan β = 1.5 and 94.1 GeV for tan β = 35. These limits are obtained assuming a universal scalar mass m0 ≥ 500 GeV. The corresponding limits for all m0 are 78.0 and 71.7 GeV. The 95% confidence level lower limits on the lightest neutralino mass, valid for any value of tan β are 32.8 GeV for m0 ≥ 500 GeV and 31.6 GeV for all m0.

Selectron pair production in e+e− colliders and the supergravity spectrum

Selectrons may be produced in pairs at LEPII if their mass is less than about 100 GeV. Preferably, they decay into the lightest neutralino plus an electron. In a scenario where selectrons are observed at LEPII, we show that: (i) in a first stage where experimental errors are large, the measurement of the total cross section of selectron pair production, the selectron mass, and the lightest neutralino mass, allow us to validate or rule out the Minimal Supergravity Model in its simplest form, and that (ii) in a second stage where precision measurements are available, the value of $\tan\beta$ can be determined together with the rest of the parameters that specify the Minimal Supergravity Model and, with them, the entire supersymmetric spectrum can be calculated. We include experimental constraints from sparticle searches, $Z$--pole physics, stability of the lightest supersymmetric particle (LSP) and the decay $b\rightarrow s\gamma$. In these scenarios, small values of $\tan\beta$ and negative values of $\mu$ are preferred, and the lightest Higgs mass satisfies $m_h<110$ GeV, which makes it likely to be detected at LEPII.

Search for chargino and neutralino production at

A search for charginos and neutralinos, predicted by supersymmetric theories, has been performed using a data sample of $10.3$ pb $^{-1}$ at centre-of-mass energies of $\sqrt{s} = $ 170 and 172 GeV with the OPAL detector at LEP. No evidence for these particles has been found. The results are combined with those from previous OPAL chargino and neutralino searches at lower energies to obtain limits. Exclusion regions at 95% C.L. of parameters of the Minimal Supersymmetric Standard Model are determined. Within this framework, for $\tan\beta \ge 1.0$ , lower mass limits are placed on the lightest chargino and the three lightest neutralinos. The 95% C.L. lower mass limit on the lightest chargino, assuming that it is heavier than the lightest neutralino by more than 10 GeV, is 84.5 GeV for the case of a large universal scalar mass ( $m_0 >$ 1 TeV) and 65.7 GeV for the smallest $m_0$ compatible with current limits on the sneutrino mass and slepton cross-sections. The lower limit on the lightest neutralino mass at 95% C.L. for $\tan \beta \geq 1.0$ is 24.7 GeV for $m_0 = 1$ TeV and 13.3 GeV for the minimum $m_0$ scenario. These mass limits are higher for increasing values of $\tan\beta$ . The interpretation of the limits in terms of gluino and scalar quark mass limits is also given.

Cornering the supersymmetry preferred dark matter candidate: The neutralino

In the minimal supersymmetric extension of the standard model (the Minimal Supersymmetric Standard Model, MSSM), the lightest supersymmetric particle (LSP) is stable and hence is a good dark matter candidate. The preferred LSP in this model is the lightest neutralino, which is a combination of photino, zino and higgsinos. In the MSSM, the lightest neutralino mass, composition and couplings depend on only three unknown parameters. In this talk we will show some limits on the possible values of these three parameters, coming from indirect dark matter searches and cosmology.