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 role 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\times 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.
We update the upper bound on the lightest CP even Higgs mass in the NMSSM, which is given as a function of tan(beta) and lambda. We include the available one and two loop corrections to the NMSSM Higgs masses, and constraints from the absence of Landau singularities below the GUT scale as well as from the stability of the NMSSM Higgs potential. For m_top varying between 171.4 and 178 GeV, squark masses of 1 TeV and maximal mixing the upper bound is assumed near tan(beta) ~ 2 and varies between 139.9 and 141.4 GeV.
We investigate neutralino dark matter in the framework of NMSSM performing a scan over its parameter space and calculating neutralino capture and annihilation rates in the Sun. We discuss the prospects of searches for neutralino dark matter in neutrino experiments depending on neutralino content and its main annihilation channel. We recalculate the upper limits on neutralino-proton elastic cross sections directly from neutrino telescopes upper bounds on annihilation rates in the Sun. This procedure has advantages as compared with corresponding recalcalations from the limits on muon flux, namel…
A novel computation of the fully-differential cross section for neutral Higgs-boson production through gluon fusion in the CP-conserving NMSSM is presented. Based on the calculation of NLO corrections to the total cross section [1], we implemented the NMSSM amplitudes in three codes, applying different resummation techniques: analytic transverse-momentum resummation at NLO+NLL, and two fully-differential NLO+PS Monte-Carlo approaches using the MC@NLO and POWHEG matching procedures, respectively. We study phenomenological predictions for distributions in the NMSSM with a special emphasis on the…
In this work, we study the direct-detection constraints of light dark matter in the next-to minimal supersymmetric standard model (NMSSM) with non-universal Higgs masses (NUHM), especially the correlation between higgsino asymmetry and spin-dependent cross section. Finally, we get the following conclusions: (i) The spin-dependent cross section is proportional to the square of higgsino asymmetry in dark matter $\tildeχ^0_1$ in the NMSSM-NUHM. (ii) For highly singlino-dominated dark matter $\tildeχ^0_1$, the relic density can be sufficient, but the higgsino asymmetry and spin-dependent cross sec…
We examine in detail radiative corrections to the lightest scalar Higgs boson mass due to the top quark and scalar quark loops in the next-to-minimal supersymmetric standard model (NMSSM). We take into account the nondegenerate state for the top scalar quark masses. In our analysis, the mass matrix of the top scalar quark contains the gauge terms. Therefore our formula for the scalar Higgs boson mass matrix at the 1-loop level includes the contribution of the gauge sector as well as the effect of the top scalar quark mass splitting. Thus we calculate the upper bound on the lightest scalar Higg…
We study the implication of triviality on Higgs sector in next to minimal supersymmetric model (NMSSM) using variational field theory. It is shown that mass of the lightest Higgs boson in NMSSM has an upper bound $\sim 10\, M_W$ which is of the same order as that in standard model.
Spin-independent cross-section for neutralino dark matter scattering off nuclei is investigated in the NMSSM. Several classes of blind spots for direct detection of singlino-Higgsino dark matter are analytically identified, including such that have no analog in the MSSM. It is shown that mixing of the Higgs doublets with the scalar singlet has a big impact on the position of blind spots in the parameter space. In particular, this mixing allows for more freedom in the sign assignment for the parameters entering the neutralino mass matrix, required for a blind spot to occur, as compared to the M…
In the NMSSM it is well possible to find an additional Higgs boson with a mass below 125 GeV which remains invisible in standard Higgs boson search channels. We study the Higgs pair production cross sections times branching fractions in this scenario, focusing on gluon fusion and the bb+tautau and bb+gammagamma final states. Summing over the SM-like and the lighter Higgs states, the production cross sections times branching fractions are never below the ones for SM Higgs pair production. Sizable enhancements of the signal rates are also possible, notably if a lighter Higgs state is produced. H…
We study the parameter space of the semi-constrained NMSSM, compatible with constraints on the Standard Model like Higgs mass and signal rates, constraints from searches for squarks and gluinos, a dark matter relic density compatible with bounds from WMAP/Planck, and direct detection cross sections compatible with constraints from LUX. The remaining parameter space allows for a fine-tuning as low as about 100, an additional lighter Higgs boson in the 60-120 GeV mass range detectable in the diphoton mode or in decays into a pair of lighter CP-odd Higgs bosons, and dominantly singlino like dark …
We analyze the stability of the vacuum and the electroweak phase transition in the NMSSM close to the Peccei-Quinn symmetry limit. This limit contains light Dark Matter (DM) particles with a mass significantly smaller than the weak scale and also light CP-even and CP-odd Higgs bosons. Such light particles lead to a consistent relic density and facilitate a large spin-independent direct DM detection cross section, that may accommodate the recently reported signatures at the DAMA and CoGeNT experiments. Studying the one-loop effective potential at finite temperature, we show that when the lighte…
We study the upper mass bound of the lightest neutral Higgs scalar in the NMSSM using the RGE analysis. We require the successful occurence of the electroweak radiative symmetry breaking to restrict the parameter space. As a result the upper mass bound $m_{h^0}$ is largely restricted compared with the one estimated without imposing this condition. We point out some features of $m_{h^0}$ related to the initial value of $h_t$ and discuss why the models with more extra matters ${\bf 5}+\bar{\bf 5}$ of SU(5) could bring the larger maximum value of $m_{h^0}$.
We address the direct detection of neutralino dark matter in the framework of the Next-to-Minimal Supersymmetric Standard Model. We conduct a detailed analysis of the parameter space, taking into account all the available constraints from LEPII, and compute the neutralino-nucleon cross section. We find that sizable values for the detection cross section, within the reach of dark matter detectors, are attainable in this framework, and are associated with the exchange of very light Higgses, $m_{h_1^0}\lesssim 70$ GeV, the latter exhibiting a significant singlet composition.
We analyze the direct detection of neutralino dark matter in the framework of the Next-to-Minimal Supersymmetric Standard Model. Taking into account all the available constraints from LEPII and Tevatron, including bounds from the muon anomalous magnetic moment and flavor constraint as $b \to s γ$, we compute the neutralino-nucleon cross section and compare the results with the sensitivity of dark matter detectors. We also study the relic abundance of neutralinos, comparing it with WMAP observations. We show that a light singlet-like Higgs can escape accelerator constraints allowing for scenari…
We place perturbative unitarity constraints on both the dimensionful and dimensionless parameters in the Next-to-Minimal Supersymmetric Standard Model (NMSSM) Higgs Sector. These constraints, plus the requirement that the singlino and/or Higgsino constitutes at least part of the observed dark matter relic abundance, generate upper bounds on the Higgs, neutralino and chargino mass spectrum. Requiring higher order corrections to be no more than 41% of the tree-level value, we obtain an upper bound of 20 TeV for the heavy Higgses and 12 TeV for the charginos and neutralinos outside defined fine-t…
We study the associated production of a charged Higgs and a W boson in high-energy pp collisions at the Large Hadron Collider. This is an interesting process for charged Higgs discovery, or exclusion, since the production cross section could depend strongly on the model, offering potential discriminating power between supersymmetric extensions of the Standard Model with minimal or extended Higgs sectors. We compute the cross section for this process in the next-to-minimal supersymmetric Standard Model (NMSSM), at the tree level for quark-quark scattering and at one-loop level for gluon-gluon s…
Thermal leptogenesis in the canonical seesaw model in supersymmetry suffers from the incompatibility of a generic lower bound on the mass scale of the lightest right-handed neutrino and the upper bound on the reheating temperature of the Universe after inflation. This is resolved by adding an extra singlet superfield, with a discrete $Z_2$ symmetry, to the NMSSM (Next to Minimal Supersymmetric Standard Model). This generic mechanism is applicable to any supersymmetric model for lowering the scale of leptogenesis.
In the next-to minimal supersymmetric standard model (NMSSM) one additional singlet-like Higgs boson with small couplings to standard model (SM) particles is introduced. Although the mass can be well below the discovered 125 GeV Higgs boson mass its small couplings may make a discovery at the LHC difficult. We use a novel scanning technique to efficiently scan the whole parameter space and determine the range of cross sections and branching ratios for the light singlet-like Higgs boson below 125 GeV. This allows to determine the perspectives for the future discovery potential at the LHC. Speci…
We give the upper bounds on the masses of the lightest and second lightest CP even Higgs bosons in the NMSSM, the MSSM extended by a gauge singlet. The dominant two loop corrections are included. Since the coupling R of the lightest Higgs scalar to gauge bosons can be small, we study in detail the relation between masses and couplings of both lightest scalars. We present upper bounds on the mass of a 'strongly' coupled Higgs (R>1/2) as a function of lower experimental limits on the mass of a 'weakly' coupled Higgs (R<1/2). With the help of these results, the whole parameter space of the model …
The excess of events in the diphoton final state near 750 GeV observed by ATLAS and CMS can be explained within the NMSSM near the R-symmetry limit. Both scalars beyond the Standard Model Higgs boson have masses near 750 GeV, mix strongly, and share sizeable production cross sections in association with b-quarks as well as branching fractions into a pair of very light pseudoscalars. Pseudoscalars with a mass of ~ 210 MeV decay into collimated diphotons, whereas pseudoscalars with a mass of ~ 500-550 MeV can decay either into collimated diphotons or into three pi^0 resulting in collimated photo…
In the Next-to-Minimal Supersymmetric Standard Model, neutralino dark matter can annihilate into a pair of photons through the exchange of a CP-odd Higgs boson in the s-channel. The CP-odd Higgs boson couples to two photons through a loop of dominantly higgsino-like charginos. We show that the parameter space of the NMSSM can accommodate simultaneously i) neutralino-like dark matter of a mass of about 130 GeV giving rise to a 130 GeV photon line; ii) an annihilation cross section of or larger than 10^{-27}cm^3s^{-1}; iii) a relic density in agreement with WMAP constraints; iv) a direct detecti…
Next-to-Minimal Supersymmetric Standard Model neutralino dark matter candidates in the (1-15) GeV range are found with a Markov Chain Monte Carlo scanning code. A very light, singlet-like Higgs and/or CP-odd Higgs is needed in order to achieve such light masses. Light scalar Higgses can yield large direct detection cross sections, suitable for an account of the recent claims for signals. Neutralino annihilations via resonant light pseudoscalar Higgs exchanges can overproduce the indirect yield of gamma-rays from dwarf spheroidal galaxies. Hence, direct and indirect detection experiments probe …
The problem of the lightest Higgs boson mass in the next-to-minimal supersymmetric standard model (NMSSM) is investigated. Assuming the validity of the perturbation theory up to unification scales and using the recent experimental results for the top quark mass, the restrictions on the NMSSM coupling constants are obtained. These restrictions are used to make the predictions for the lightest Higgs mass, which are compared to those of the minimal supersymmetric standard model (MSSM).
We provide a scan of the parameter space for neutralino-hadron scattering in the next-to-minimal supersymmetric standard model using an updated value for the strange quark sigma commutator. These results also take into account constraints from WMAP data on the relic density and new constraints from the Large Hadron Collider. We find that the resultant spin-independent cross sections are smaller in magnitude than those found in recent results obtained within the constrained minimal supersymmetric standard model, yet still great enough to feasibly allow for detection in the case of bino-like neu…
This work studies the self-interacting dark matter (SIDM) scenario in the general NMSSM and beyond, where the dark matter is a Majorana fermion and the force mediator is a scalar boson. An improved analytical expression for the dark matter (DM) self-interacting cross section which takes into account the Born level effects is proposed. Due to the large couplings and light mediator in SIDM scenario, the DM/mediator will go through multiple branchings if they are produced with high energy. Based on the Monte Carlo simulation of the showers in the DM sector, we obtain the multiplicities and the sp…
A substantial contribution to the SM-like Higgs mass may come from the mixing with the lightest singlet-dominated scalar in NMSSM for moderate or large values of $\tanβ$ [1]. The LSP neutralino in this model may also contain the singlet component - singlino. In this work we analyze the direct detection cross section for a Higgsino-singlino LSP with the emphasis on possible direct detection blind spots in the parameter space. Correlations between the LSP properties and the effects in the Higgs sector coming from the mixing are also discussed.
We analyse the direct detection of neutralino dark matter in the framework of the Next-to-Minimal Supersymmetric Standard Model. After performing a detailed analysis of the parameter space, taking into account all the available constraints from LEPII, we compute the neutralino-nucleon cross section, and compare the results with the sensitivity of detectors. We find that sizable values for the detection cross section, within the reach of dark matter detectors, are attainable in this framework. For example, neutralino-proton cross sections compatible with the sensitivity of present experiments c…
We study the properties of the right-handed sneutrino and its viability as a WIMP dark matter candidate in an extended version of the NMSSM in which a right-handed neutrino superfield is included with a coupling to the singlet Higgs in order to provide non-vanishing Majorana neutrino masses. We perform a systematic study of the parameter space, including LEP constraints and experimental bounds on low-energy observables. We investigate the conditions under which the right-handed sneutrino has the correct relic abundance and the dominant annihilation channels. Next we calculate the theoretical p…
We study the NMSSM with universal Susy breaking terms (besides the Higgs sector) at the GUT scale. Within this constrained parameter space, it is not difficult to find a Higgs boson with a mass of about 125 GeV and an enhanced cross section in the diphoton channel. An additional lighter Higgs boson with reduced couplings and a mass <123 GeV is potentially observable at the LHC. The NMSSM-specific Yukawa couplings lambda and kappa are relatively large and tan(beta) is small, such that lambda, kappa and the top Yukawa coupling are of order 1 at the GUT scale. The lightest stop can be as light as…
We present benchmark planes (or lines) with cross sections via gluon fusion for the processes $H\to h+H_{S}$, resonant Higgs pair and triple Higgs production, $A \to h+(A_S \to γγ)$, $A \to Z+ h$ and $A \to Z+ H_{S}$ within the Next-to-Minimal Supersymmetric Standard Model. Moreover we propose new searches for $H\to h+(H_{S} \to t\bar{t})$, $A \to Z+ (H_{S}\to h+h)$ and $A \to Z+ (H_{S}\to t\bar{t})$ for which possible cross sections are given. These allow the experimental collaborations to verify in the future which search channels cover yet unexplored regions of the parameter space. Expressi…
The light higgsino-singlino scenario of the NMSSM allows to combine a naturally small $μ$ parameter with a good dark matter relic density. Given the new constraints on spin-dependent and spin-independent direct detection cross sections in 2016 we study first which regions in the plane of chargino- and LSP-masses below 300 GeV remain viable. Subsequently we investigate the impact of searches for charginos and neutralinos at the LHC, and find that the limits from run I do not rule out any additional region in this plane. Only the HL-LHC at 3000 fb$^{-1}$ will test parts of this plane correspondi…
In the framework of the NMSSM with a singlino-like LSP, we study quantitatively the impact of the additional bino -> singlino cascade on the efficiencies in several search channels for supersymmetry of the ATLAS and CMS collaborations. Compared to the MSSM, the additional cascade reduces the missing transverse energy, but leads to additional jets or leptons. For the NMSSM benchmark lines which generalize cMSSM benchmark points, the efficiencies in the most relevant 2/3 jet + missing energy search channels can drop by factors ~1/3 to ~1/7, and can reduce the present lower bounds on M_{1/2} by a…
We study the viability of the lightest neutralino as a dark matter candidate in the Next-to-Minimal Supersymmetric Standard Model. Taking into account accelerator constraints as well as bounds on low-energy observables, and imposing consistency with present bounds on the neutralino relic density, we address the prospects for the direct detection of neutralino dark matter. We find regions of the allowed parameter space where the neutralino detection cross section is within the reach of dark matter detectors, essentially owing to the presence of very light singlet-like Higgses, and to either sin…
We reexamine the constrained version of the Next-to-Minimal Supersymmetric Standard Model with semi universal parameters at the GUT scale (CNMSSM). We include constraints from collider searches for Higgs and SUSY particles, upper bound on the relic density of dark matter, measurements of the muon anomalous magnetic moment and of B-physics observables as well as direct searches for dark matter. We then study the prospects for direct detection of dark matter in large scale detectors and comment on the prospects for discovery of heavy Higgs states at the LHC.
A light singlino is a promising candidate for dark matter, and a light higgsino is natural in the parameter space of the NMSSM. We study the combined constraints on this scenario resulting from the dark matter relic density, the most recent results from direct detection experiments, LEP and the LHC. In particular limits from a recent search for electroweak production of charginos and neutralinos at $\sqrt{s}=13$ TeV after 35.9 fb$^{-1}$ by CMS and constraints on spin-independent dark matter-nucleon cross sections from XENON1T after one tonne$\times$year exposure are considered. We find that sc…
In the Next-to-Minimal-Supersymmetric-Standard-Model (NMSSM) the lightest supersymmetric particle (LSP) is a candidate for the dark matter (DM) in the universe. It is a mixture from the various gauginos and Higgsinos and can be bino-, Higgsino- or singlino-dominated. Singlino-dominated LSPs can have very low cross sections below the neutrino background from coherent neutrino scattering which is limiting the sensitivity of future direct DM search experiments. However, previous studies suggested that the combination of both, the spin-dependent (SD) and spin-independent (SI) searches are sensitiv…
In a recent paper arXiv:1107.5048, we discussed the correlation between the elastic neutralino-nucleon scattering cross section, constrained by dark matter direct detection experiments, and fine-tuning at tree-level in the electroweak symmetry breaking sector of the Minimal Supersymmetric Standard Model (MSSM). Here, we show that the correlation persists in the Next-to-Minimal Supersymmetric Standard Model (NMSSM), and its variant, lambda-SUSY. Both models are strongly motivated by the recent discovery of a 125 GeV Higgs-like particle. We also discuss the implications of the recently published…
The Higgs sectors of supersymmetric extensions of the Standard Model have two doublets in the minimal version (MSSM), and two doublets plus a singlet in two others: with (UMSSM) and without (NMSSM) an extra U(1)'. A very concise comparison of these three models is possible if we assume that the singlet has a somewhat larger breaking scale compared to the electroweak scale. In that case, the UMSSM and the NMSSM become effectively two-Higgs-doublet models (THDM), like the MSSM. As expected, the mass of the lightest CP-even neutral Higgs boson has an upper bound in each case. We find that in the …
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 o…
This paper investigates the impact of the recent LHC constraints on the Higgs sector in the semi-constrained version of the Next-to-Minimal Supersymmetric Standard Model. Our analysis focuses on the parameter space for which the value of the Higgs doublet-singlet coupling, $λ$, is large as possible, while the ratio between the vacuum expectation values of the two Higgs doublets, $\tanβ$, is small as possible. Under the current constraints, we present the possible fermionic decay channels and reduced cross-section into fermions final states for the lightest neutral Higgs bosons in the NMSSM, $(…
Singlino-dominated dark matter properties are investigated in the $Z_3$ Next-to-Minimal Supersymmetric Standard Model, producing superweak interactions with nucleons involved in dark matter direct detection experiments. Approximate analytical formulas describing the dark matter abundance and cross section in the scattering with nucleons are used to illustrate a dependence on theoretical parameters in neutralino and Higgs sectors. It is shown that the measured abundance requires a sizable singlet--doublet Higgs coupling parameter $λ$, while the experimental detection results prefer a small $λ$.…
The next-to-minimal supersymmetric model (NMSSM) with a large lambda (the mixing parameter between the singlet and doublet Higgs fields) is well motivated since it can significantly push up the upper bound on the SM-like Higgs boson mass to solve the little hierarchy problem. In this work we examine the current experimental constraints on the NMSSM with a large lambda, which include the direct search for Higgs boson and sparticles at colliders, the indirect constraints from precision electroweak measurements, the cosmic dark matter relic density, the muon anomalous magnetic moment, as well as …
We perform a comparative study of the neutralino dark matter scattering on nucleon in three popular supersymmetric models: the minimal (MSSM), the next-to-minimal (NMSSM) and the nearly minimal (nMSSM). First, we give the predictions of the elastic cross section by scanning over the parameter space allowed by various direct and indirect constraints, which are from the measurement of the cosmic dark matter relic density, the collider search for Higgs boson and sparticles, the precision electroweak measurements and the muon anomalous magnetic moment. Then we demonstrate the property of the allow…
We study a region in the NMSSM parameter space in which the mass of the SM-like Higgs boson is uplifted by ~4-17 GeV, allowing for stop masses and |A_t| <= 1 TeV alleviating the little fine tuning problem of the MSSM. An uplift of the mass of the SM-like Higgs boson is possible in two distinct regions in the NMSSM parameter space: Either for large lambda and small tan(beta) or, through singlet-doublet mixing, for small lambda and large tan(beta). For a mostly singlet-like Higgs state H_S with a mass below 125 GeV we investigate possible direct or indirect search channels at the run II of the L…
Relatively light stops in gauge mediation models are usually made compatible with the Higgs mass of 125 GeV by introducing direct Higgs-messenger couplings. We show that such couplings are not necessary in a simple and predictive model that combines minimal gauge mediation and the next-to-minimal supersymmetric standard model (NMSSM). We show that one can obtain a 125 GeV Standard Model-like Higgs boson with stops as light as 1.1 TeV, thanks to the mixing of the Higgs with a singlet state at ${\cal O}(90-100)$ GeV that can explain the LEP excess. In this scenario the singlet-higgs-higgs superf…
We study the implications of the triviality problem for the Higgs masses and other relevant parameters in the Next to Minimal Supersymmetric Standard Model (NMSSM). By means of triviality, a new way to constrain parameters is proposed, and therefore we are able to derive triviality bounds on the heaviest-Higgs mass, the lightest-Higgs mass, the soft SUSY- breaking parameters, and the vacuum expectation value of the Higgs gauge singlet through a thorough examination of the parameter space. The triviality upper bound on the lightest-Higgs mass predicted by NMSSM is indeed larger than the upper b…
For the experimental search of neutralino dark matter, it is important to know its allowed mass and scattering cross section with the nucleon. In order to figure out how light a neutralino dark matter can be predicted in low energy supersymmetry, we scan over the parameter space of the NMSSM (next-to-minimal supersymmetric model), assuming all the relevant soft mass parameters to be below TeV scale. We find that in the parameter space allowed by current experiments the neutralino dark matter can be as light as a few GeV and its scattering rate off the nucleon can reach the sensitivity of XENON…
Recent results from the Cryogenic Dark Matter Search (CDMS) experiment have renewed interest in light dark matter with a large spin-independent neutralino-nucleon scattering cross-section. Here, we examine the regions of the Next-to-MSSM (NMSSM) capable of producing a light neutralino with a large spin-independent scattering cross-section, with the scattering mediated by a very light singlet-like scalar, and a 126 GeV Standard Model-like Higgs consistent with the LHC results, while satisfying other relevant cosmological, flavor and collider constraints. We focus on two different scenarios for …
In the Next-to-Minimal Supersymmetric Standard Model with the inverse seesaw mechanism to generate neutrino masses, the lightest sneutrino may act as a feasible dark matter candidate in vast parameter space. In this case, the smallness of the leptonic unitarity violation and the recent XENON-1T experiment can limit the dark matter physics. In particular, they set upper bounds of the neutrino Yukawa couplings $λ_ν$ and $Y_ν$. We study such effects by encoding the constraints in a likelihood function and carrying out elaborated scans over the parameter space of the theory with the Nested Samplin…
We study spectral features in the gamma-ray emission from dark matter (DM) annihilation in the Next-to-Minimal Supersymmetric Standard Model (NMSSM), with either neutralino or right-handed (RH) sneutrino DM. We perform a series of scans over the NMSSM parameter space, compute the DM annihilation cross section into two photons and the contribution of box-shaped features, and compare them with the limits derived from the Fermi-LAT search for gamma-ray lines using the latest Pass 8 data. We implement the LHC bounds on the Higgs sector and on the masses of supersymmetric particles as well as the c…
Since the recent results of direct detection experiments at low mass, many authors have revisited the case of light (1 -10) GeV WIMPs. In particular, there have been a few attempts to explain the results from the DAMA/LIBRA, CDMS and/or CoGeNT experiments by invoking neutralinos lighter than 15 GeV. Here we show that in the MSSM, such light particles are completely ruled out by the TEVATRON limits on the mass of the pseudoscalar Higgs. On the contrary, in the NMSSM, we find that light neutralinos could still be viable candidates. In fact, in some cases, they may even have an elastic scattering…
Though the mass of Higgs particle is the parameter determined by the experiment in the standard model (SM), SUSY models have rather predictive power for the lightest Higgs mass, and its upper bound in some SUSY models are close to the observable region in LEP2. The upper bound of the lightest Higgs mass is analysed systematically on the basis of the $CP$ violation in the minimal and the next minimal supersymmetric standard model (MSSM and NMSSM). In the explicit $CP$ violation case, the mass bound is large around $130 \sim 160$ GeV in both models. In the spontaneous $CP$ violation case induced…
We assess the extent to which the NMSSM can allow for light dark matter in the $2\gev\lsim \mcnone\lsim 12\gev$ mass range with correct relic density and large spin-independent direct-detection cross section, $\sigsi$, in the range suggested by \cogent\ and DAMA. For standard assumptions regarding nucleon $s$-quark content and cosmological relic density, $ρ$, we find that the NMSSM falls short by a factor of about 10 to 15 (3 to 5) without (with) significant violation of the current $(g-2)_μ$ constraints.
In the natural realization of the Next-to-minimal Supersymmetric Standard Model, Higgsinos tend to be lighter than about several hundred GeVs, which can induce detectable leptonic signals at the LHC as well as large DM-nucleon scattering cross section. We explore the constraints from the direct searches for electroweakino and slepton at the LHC Run II and the latest DM direct detection experiments on the scenario with low fine tuning indicator $Δ_{Z/h} \leq 50$. We find that these experiments are complementary to each other in excluding the scenario, and as far as each kind of experiment is co…
Given the fact that the relatively light Higgsino mass $μ$ favored in natural supersymmetry usually results in a sizable scattering cross section between the neutralino dark matter and the nucleon, we study the impact of the recently updated direct detection bounds from LUX experiment, including both Spin Independent (SI) and Spin Dependent (SD) measurements, on the parameter space of natural Next-to-Minimal Supersymmetric Standard Model (nNMSSM). Different from the common impression that the SI bound is stronger than the SD one, we find that the SD bound is complementary to the SI bound and i…
A highly bino-like Dark Matter (DM), which is the Lightest Supersymmetric Particle (LSP), could be motivated by the stringent upper bounds on the DM direct detection rates. This is especially so when its mass is around or below 100 GeV for which such a bound tends to get most severe. Requiring not so large a higgsino mass parameter, that would render the scenario reasonably natural, prompts such a bino-like state to be relatively light. In the Minimal Supersymmetric Standard Model (MSSM), in the absence of comparably light scalars, such an excitation, if it has to be a thermal relic, is unable…
