As discussed recently by Hooper and Tait, the singlino-like dark matter in the Minimal Supersymmetric Standard Model (MSSM) extended by a singlet Higgs superfield can give a perfect explanation for both the relic density and the Pamela result through the Sommerfeld-enhanced annihilation into singlet Higgs bosons ($a$ or $h$ followed by $h->a a$) with $a$ being light enough to decay dominantly to muons or electrons. In this work we analyze the parameter space required by such a dark matter explanation and also consider the constraints from the LEP experiments. We find that although the light singlet Higgs bosons have small mixings with the Higgs doublets in the allowed parameter space, their couplings with the SM-like Higgs boson $h_{SM}$ (the lightest doublet-dominant Higgs boson) can be enhanced by the soft parameter $A_κ$ and, in order to meet the stringent LEP constraints, the $h_{SM}$ tends to decay into the singlet Higgs pairs $aa$ or $hh$ instead of $b\bar b$. So the $h_{SM}$ produced at the LHC will give a multi-muon signal, h_{SM} -> aa -> 4 muons or h_{SM} -> hh -> 4 a -> 8 muons.
We take the MSSM as a complete theory of low energy phenomena, including neutrino masses and mixings. This immediately implies that the gravitino is the only possible dark matter candidate. We study the implications of the astrophysical experiments such as PAMELA and Fermi-LAT, on this scenario. The theory can account for both the realistic neutrino masses and mixings, and the PAMELA data as long as the slepton masses lie in the $500-10^6 $TeV range. The squarks can be either light or heavy, depending on their contribution to radiative neutrino masses. On the other hand, the Fermi-LAT data imp…
We present the dark matter (DM) extension (by N) of the minimal supersymmetric standard model to give the recent trend of the high energy positron spectrum of the PAMELA/HEAT experiments. If the trend survives by future experiments, the MSSM needs to be extended. Here, we minimally extend the MSSM with one more DM component N together with a heavy lepton E, and introduce the coupling e_R E_R^c N_R. This coupling naturally appears in the flipped SU(5) GUT models. This N_{DM}MSSM contains the discrete symmetry Z_6, and for some parameter ranges there result two DM components. For the MSSM fields…
We consider a scenario within the Minimal Supersymmetric Standard Model extended by a singlet chiral superfield, in which neutralino dark matter annihilates to light singlet-like Higgs bosons, which proceed to decay to either electron-positron or muon-antimuon pairs. Unlike neutralino annihilations in the MSSM, this model can provide a good fit to the PAMELA cosmic ray positron fraction excess. Furthermore, the singlet-like scalar Higgs can induce a large Sommerfeld enhancement and provide an annihilation rate sufficient to accommodate the observed positron excess.
Recent data on $e^+/e^-$ and $\bar{p}$ cosmic rays suggest that dark matter annihilate into the standard model (SM) particles through new leptophilic interaction. In this paper, we consider a standard model extension with the gauged $U(1)_{L_μ- L_τ}$ group, with a new Dirac fermion charged under this U(1) as a dark matter. We study the muon $(g-2)_μ$, thermal relic density of the cold dark matter, and the collider signatures of this model. $Z^{'}$ productions at the Tevatron or the LHC could be easily order of $O(1)-O(10^3)$ fb.
Positron excess upto energies $\sim$350 GeV has been observed by AMS-02 result and it is consistent with the positron excess observed by PAMELA upto 100 GeV. There is no observed excess of anti-protons over the expected CR background. We propose a leptophilic dark matter with an $U(1)_{L_μ-L_τ}$ gauge extension of MSSM. The dark matter is an admixture of the $L_μ-L_τ$ gaugino and fermionic partners of the extra $SU(2)$ singlet Higgs boson, which break the $L_μ-L_τ$ symmetry. We construct the SM$\otimes U(1)_{ L_μ-L_τ}$ SUSY model which provides the correct relic density of dark matter and is c…
We discuss various phenomenological aspects of supersymmetric models beyond the MSSM. A particular focus is on models which can correctly explain neutrino data and the possiblities of LHC to identify the underlying scenario.
In this note we briefly review the recent studies of dark matter in the MSSM and its singlet extensions: the NMSSM, the nMSSM, and the general singlet extension. Under the new detection results of CDMS II, XENON, CoGeNT and PAMELA, we find that (i) the latest detection results can exclude a large part of the parameter space which allowed by current collider constraints in these models. The future SuperCDMS and XENON can cover most of the allowed parameter space; (ii) the singlet sector will decouple from the MSSM-like sector in the NMSSM, however, singlet sector makes the nMSSM quite different…
A short review of the theory and phenomenology of Higgs bosons is given, with focus on the Standard Model (SM) and the minimal supersymmetric extension of the Standard Model (MSSM). The potential for Higgs boson discovery at the Tevatron and LHC, and precision Higgs studies at the LHC and a future e+e- linear collider are briefly surveyed. The phenomenological challenge of the approach to the decoupling limit, where the properties of the lightest CP-even Higgs boson of the MSSM are nearly indistinguishable from those of the SM Higgs boson is emphasized.
In this article I review some aspects of flavour phenomenology in the MSSM. After an overview of various flavour observables I discuss the constraints on the off-diagonal elements of the squark mass matrices. In this context I present the Fortran code SUSY_FLAVOR which calculates these processes in the generic MSSM including the complete resummation of all chirally enhanced effects as a new feature of version 2. Than I discuss where large new physics effects in the MSSM are still possible. As an example of a model which can give large effects in flavour physics I review a model with "radiative…
We discuss aspects of the low energy phenomenology of the MSSM, in the large $\tan β $ regime. We explore the regions of the parameter space where the $h_t$ and $h_b$ Yukawa couplings exhibit a fixed point structure, using previous analytic solutions for these couplings. Expressions for the parameters $A_{t}$ and $A_{b}$ and the renormalised soft mass terms are also derived, making it possible to estimate analytically the sparticle loop -- corrections to the bottom mass, which are important in this limit.
In the MSSM with complex SUSY parameters we consider a specific case where the second heaviest Higgs boson H_2 is SM like, while H_1 and H_3 are both strongly mixed states of CP odd and CP even scalar fields. Such a scenario could be probed at a Linear Collider via the mechanism e^+e^-\to H_1H_3.
The E6SSM is a promising model based on the group E6, assumed to be broken at the GUT scale, leading to the group SU(3)\times SU(2)\times U(1)\times U(1)' at the TeV scale. It gives a solution to the MSSM μ-problem without introducing massless axions, gauge anomalies or cosmological domain walls. The model contains three families of complete 27s of E6, giving a richer phenomenology than the MSSM. The E6SSM generically predicts gluino cascade decay chains which are about 2 steps longer than the MSSM's due to the presence of several light neutralino states. This implies less missing (and more vi…
The Higgs sector of the minimal supersymmetric standard model (MSSM) consists of five physical Higgs bosons, which offer a variety of channels for their experimental search. The present study aims to further our understanding of the Tevatron reach for MSSM Higgs bosons, addressing relevant theoretical issues related to the SUSY parameter space, with special emphasis on the radiative corrections to the down--quark and lepton couplings to the Higgs bosons for large $\tanβ$. We performed a computation of the signal and backgrounds for the production processes $Wϕ$ and $b \bar{b} ϕ$ at the upgrade…
We perform a detailed analysis of several mu-tau lepton flavour violating (LFV) processes, namely tau --> mu X (X = gamma, e+ e-, mu+ mu-, rho, pi, eta, eta'), Z --> mu tau and Higgs boson decays into mu tau. First we present a model independent operator analysis relevant to such decays, then we explicitly compute the LFV operator coefficients [and (g_μ-2)] in a general unconstrained MSSM framework, allowing slepton mass matrices to have large mu-tau entries. We systematically study the role and the interplay of dipole and non-dipole operators, showing how the rates and the mutual correlations…
The recent positron excess in cosmic rays (CR) observed by the PAMELA satellite may be a signal for dark matter (DM) annihilation. When these measurements are combined with those from FERMI on the total ($e^++e^-$) flux and from PAMELA itself on the $\bar p/p$ ratio, these and other results are difficult to reconcile with traditional models of DM, including the conventional mSUGRA version of Supersymmetry even if boosts as large as $10^{3-4}$ are allowed. In this paper, we combine the results of a previously obtained scan over a more general 19-parameter subspace of the MSSM with a correspondi…
We have found that in the MSSM, the possibility for the lightest CP-even Higgs boson to be lighter than $Z$ boson (as low as about 60 GeV) is, contrary to the usual belief, not yet excluded by LEP2 Higgs search nor any direct searches for supersymmetric particles at high energy colliders. The Light Higgs boson scenario (LHS) is realised when the $ZZh$ coupling and the decay branching ratio ${\rm Br}(h/A\to b\bar{b})$ are simultaneously suppressed as a result of generic supersymmetric loop corrections. Consequently, the $W^\pm H^\mp h$ coupling has to be large due to the sum rule of Higgs coupl…
We propose a new class of R-parity violating extension of MSSM with type II seesaw mechanism for neutrino masses where an unstable gravitino is the dark matter of the Universe. It decays predominantly into three leptons final states, thereby providing a natural explanation of the positron excess but no antiproton excess in the PAMELA experiment. The model can explain neutrino masses without invoking any high scale physics while keeping the pre-existing baryon asymmetry of the universe in tact.
We analyze two minimal supersymmetric constrained models with low-energy vector-like matter preserving gauge coupling unification. In one we add to the MSSM spectrum a pair of 5-plets of SU(5), in the other a pair of 10-plets. We show that the muon g-2 anomaly can be explained in these models while retaining perturbativity up to the unification scale, satisfying electroweak and flavor precision tests and current LHC data. We examine also some related phenomenological features of the models, including Higgs mass, fine-tuning, dark matter and several LHC signatures. We stress that, at least for …
We explore the implications of electroweak baryogenesis for future searches for permanent electric dipole moments in the context of the minimal supersymmetric extension of the Standard Model (MSSM). From a cosmological standpoint, we point out that regions of parameter space that over-produce relic lightest supersymmetric particles can be salvaged only by assuming a dilution of the particle relic density that makes it compatible with the dark matter density: this dilution must occur after dark matter freeze-out, which ordinarily takes place after electroweak baryogenesis, implying the same deg…
In the framework of a 2HDM effective lagrangian for the MSSM, we analyse important phenomenological aspects associated with quantum soft SUSY-breaking effects that modify the relation between the bottom mass and the bottom Yukawa coupling. We derive a resummation of the dominant supersymmetric corrections for large values of \tb to all orders in perturbation theory. With the help of the operator product expansion we also perform the resummation of the leading and next-to-leading logarithms of the standard QCD corrections. We use these resummation procedures to compute the radiative corrections…
The first chapter serves as an introduction to the MSSM. I briefly review the model and explain why stops and sbottoms provide an interesting playground for exploring and testing this model. In the second chapter I discuss stop and sbottom production at lepton colliders. I give the analytical formulae for the production cross sections at e+e- and mu+mu- colliders including (general) beam polarization. A numerical analysis shows the cross sections that can be expected at LEP2, an e+e- Linear Collider, and a Muon Collider. In particular, I address the topics of what can be gained by using polari…
We briefly review the supersymetric explanation for the cosmic dark matter. Although the neutralino in the minimal supersymmetric model (MSSM), the next-to-minimal supersymmetric model (NMSSM) and the nearly minimal supersymmetric model (nMSSM) can naturaly explain the dark matter relic density, the PAMELA result can hardly be explained in these popular models. In the general singlet extension of the MSSM, both the PAMELA result and the relic density can be explained by the singlino-like neutralino. Such singlino-like neutralinos annihilate into the singlet-like Higgs bosons, which are light e…
We present an analysis of low energy CP violating observables in the Minimal Supersymmetric Standard Model (MSSM). We focus on the predictions of CP violation in b -> s transitions in the framework of a flavor blind MSSM, where the CKM matrix remains the only source of flavor violation, but additional CP violating phases are introduced in the soft SUSY breaking sector. We find large and strongly correlated effects in Delta F = 0 observables like the electric dipole moments (EDMs) of the electron and the neutron, as well as in Delta F = 1 observables like the time dependent CP asymmetries in B …
The minimal supersymmetric extension of the Standard Model (MSSM) is reviewed. In the most general framework with minimal field content and R-parity conservation, the MSSM is a 124-parameter model (henceforth called MSSM-124). An acceptable phenomenology occurs only at exceptional points (and small perturbations around these points) of MSSM-124 parameter space. Among the topics addressed in this review are: gauge coupling unification, precision electroweak data, phenomenology of the MSSM Higgs sector, and supersymmetry searches at present and future colliders. The implications of approaches be…
We briefly review the status of motivated beyond-the-MSSM phenomenology in the light of the LHC searches to date. In particular, we discuss the conceptual consequences of the exclusion bounds, of the hint for a Higgs boson at about 125 GeV, and of interpreting the excess of direct CP violation in the charm sector as a signal of New Physics. We try to go into the various topics in a compact way while providing a relatively rich list of references, with particular attention to the most recent developments.
A computation of inclusive cross sections for neutral Higgs boson production through gluon fusion and bottom-quark annihilation is presented in the MSSM with complex parameters. The predictions for the gluon-fusion process are based on an explicit calculation of the leading-order cross section for arbitrary complex parameters which is supplemented by higher-order corrections: massive top- and bottom-quark contributions at NLO QCD, in the heavy top-quark effective theory the top-quark contribution up to N$^3$LO QCD including a soft expansion for the $\mathcal{CP}$-even component of the light Hi…
We suppose that the lightest supersymmetric particle (LSP) in the minimal supersymmetric standard model (MSSM) is the dark matter. The bino-like LSP can decay through the SO(10) gauge interactions, if one right-handed (RH) neutrino (ν^c_1) is lighter than the LSP and its superpartner (\tildeν^c_1) develops a vacuum expectation value (VEV), raising extremely small R-parity violation naturally. The leptonic decay modes can be dominant, if the VEV scale of {\bf 16}_H is a few orders of magnitude lower than the VEV of {\bf 45}_H (\approx 10^{16} GeV), and if a slepton (\tilde{e}^c_1) is relatively…
In this letter we consider the distinctive phenomenology of supersymmetric models in which the scale of SUSY breaking is very low, \sqrt{F}= O(TeV), focusing on the Higgs sector and the process of electroweak breaking. Using an effective Lagrangian description of the interactions between the observable fields and the SUSY breaking sector, it is shown how the conventional MSSM picture can be substantially modified. For instance, the Higgs potential has non-negligible SUSY breaking quartic couplings that can modify completely the pattern of electroweak breaking and the Higgs spectrum with respec…
We study the phenomenology of a supersymmetric left-right model, assuming minimal supergravity boundary conditions. Both left-right and (B-L) symmetries are broken at an energy scale close to, but significantly below the GUT scale. Neutrino data is explained via a seesaw mechanism. We calculate the RGEs for superpotential and soft parameters complete at 2-loop order. At low energies lepton flavour violation (LFV) and small, but potentially measurable mass splittings in the charged scalar lepton sector appear, due to the RGE running. Different from the supersymmetric 'pure seesaw' models, both,…
Recent results from direct detection experiments (Dama, CoGeNT), though subject to debate, seem to point toward a low mass (few GeV) dark matter (DM) particle. However, low mass DM candidates are not easily achieved in the MSSM nor NMSSM. As shown by some authors, singlet extensions of the MSSM can lead to GeV mass neutralinos and satisfy relic abundance constraints. We propose here to extract indirect detection constraints on these models in a generic way from cosmic-ray anti-proton measurements (PAMELA data)
We determine the degree of fine tuning needed in a generalised version of the NMSSM that follows from an underlying Z4 or Z8 R symmetry. We find that it is significantly less than is found in the MSSM or NMSSM and extends the range of Higgs mass that have acceptable fine tuning up to Higgs masses of mh ~ 130 GeV. For universal boundary conditions analogous to the CMSSM the phenomenology is rather MSSM like with the singlet states typically rather heavy. For more general boundary conditions the singlet states can be light, leading to interesting signatures at the LHC and direct detection experi…
We discuss the minimal supersymmetric $U(1)_{B-L}\times U(1)_R$ extension of the standard model. Gauge couplings unify as in the MSSM, even if the scale of $U(1)_{B-L}\times U(1)_R$ breaking is as low as order TeV and the model can be embedded into an SO(10) grand unified theory. The phenomenology of the model differs in some important aspects from the MSSM, leading potentially to rich phenomenology at the LHC. It predicts more light Higgs states and the mostly left CP-even Higgs has a mass reaching easily 125 GeV, with no constraints on the SUSY spectrum. Right sneutrinos can be the lightest …
We describe the Fortran code CPsuperH2.3, which incorporates the following updates compared with its predecessor CPsuperH2.0. It implements improved calculations of the Higgs-boson masses and mixing including stau contributions and finite threshold effects on the tau-lepton Yukawa coupling. It incorporates the LEP limits on the processes e^+ e^- to H_i Z, H_i H_j and the CMS limits on H_i to tau^+ tau^- obtained from 4.6/fb of data at a centre-of-mass energy of 7 TeV. It also includes the decay mode H_i to Z gamma and the Schiff-moment contributions to the electric dipole moments of Mercury an…
The discovery potential for the MSSM with heavy scalars at the LHC in the case of light inos is examined. We discuss the phenomenology of the model and the observables to determine the parameters. We show that for light gauginos, the model parameters can be constrained with a precision of the order of 15%.
In this work we study implications of additional non-holomorphic soft breaking terms (mu', A'_t, A'_b and A'_tau) on the MSSM phenomenology. By respecting the existing bounds on the mass measurements and restrictions coming from certain B-decays, we probe reactions of the MSSM to these additional soft breaking terms. We provide examples in which some slightly excluded solutions of the MSSM can be made to be consistent with the current experimental results. During this, even after applying additional fine-tuning constraints the non-holomorphic terms are allowed to be as large as hundreds of GeV…
A brief overview over the phenomenology of the MSSM at present and future colliders is given. The complementarity of indirect tests of the model via precision observables and of the information from the direct production of SUSY particles is emphasized. If the lightest Higgs boson of the MSSM will be detected, its mass will also play an important role as a precision observable.
For MSSM phenomenology, soft SUSY breaking dimension-three operators are important, in particular the couplings between Higgs bosons and squarks. In scattering processes, perturbative unitarity is violated at modest center-of-mass energy if these couplings are much larger than the masses of the scalar particles involved. Assuming perturbative unitarity, constraints on the trilinear couplings can be determined using a computer program that we have developed.
The $μν$SSM solves the $μ$ problem of the MSSM and explains the origin of neutrino masses by simply using right-handed neutrino superfields. The solution implies the breaking of R-parity. The properties and phenomenology of the model are briefly reviewed.
Precision electroweak data presently favors a weakly-coupled Higgs sector as the mechanism responsible for electroweak symmetry breaking. Low-energy supersymmetry provides a natural framework for weakly-coupled elementary scalars. In this review, we summarize the theoretical properties of the Standard Model (SM) Higgs boson and the Higgs sector of the minimal supersymmetric extension of the Standard Model (MSSM). We then survey the phenomenology of the SM and MSSM Higgs bosons at the Tevatron, LHC and a future e+e- linear collider. We focus on the Higgs discovery potential of present and futur…
We describe the Fortran code CPsuperH2.}, which contains several improvements and extensions of its predecessor CPsuperH. It implements improved calculations of the Higgs-boson pole masses, notably a full treatment of the 4 times 4 neutral Higgs propagator matrix including the Goldstone boson and a more complete treatment of threshold effects in self-energies and Yukawa couplings, improved treatments of two-body Higgs decays, some important three-body decays, and two-loop Higgs-mediated contributions to electric dipole moments. CPsuperH2.0 also implements an integrated treatment of several B-m…
The theoretical structure of the Higgs sector of the Minimal Supersymmetric Standard Model (MSSM) is briefly described. An outline of Higgs phenomenology at future lepton colliders is presented, and some opportunities for probing the physics of the MSSM Higgs sector at an e-e- collider are considered.
The parameter space of the Constrained Minimal supersymmetric Standard Model is considered. It is shown that for the particular choice of parameters there are some regions where long-living charged superparticles exist. Two regions of interest are the co-annihilation region with light staus, and the region with large negative trilinear scalar coupling A distinguished by light stops. The phenomenology of long-living superparticles is briefly discussed.
Gauged $U(1)_{L_μ- L_τ}$ model has been advocated for a long time in light of muon $g-2$ anomaly, which is a more than $3σ$ discrepancy between the experimental measurement and the standard model prediction. We augment this model with three right-handed neutrinos $(N_e, N_μ, N_τ)$ and a vector-like singlet fermion $(χ)$ to explain simultaneously the non-zero neutrino mass and dark matter content of the Universe, while satisfying anomalous muon $g-2$ constraints. It is shown that in a large parameter space of this model we can explain positron excess, observed at PAMELA, Fermi-LAT and AMS-02, t…
Two-loop renormalisation and Higgs phenomenology in the five-dimensional MSSM
University of Hafr Al Batin（哈夫阿尔巴廷大学）；Sudan University of Science and Technology（苏丹科学与技术大学）；University of Johannesburg（约翰内斯堡大学）；De La Salle University（德拉萨大学）；Université Lyon 1（里昂第一大学）；CNRS（法国国家科学研究中心）；IP2I（里昂-罗讷-阿尔卑斯粒子物理研究所）；University of Khartoum（喀土穆大学）
Various aspects of the Higgs boson phenomenology of the Minimal Supersymmetric Standard Model (MSSM) are reviewed. Emphasis is put on the effects of higher-order corrections. The masses and couplings are discussed in the MSSM with real and complex parameters. Higher-order corrections to Higgs boson production channels at a prospective e+ e- linear collider are investigated. Corrections to Higgs boson decays to SM fermions and their phenomenological implications for hadron and lepton colliders are explored.
We make a comprehensive study of the theory and phenomenology of a low energy supersymmetric standard model originating from a string-inspired $E_6$ grand unified gauge group. The Exceptional Supersymmetric Standard Model (ESSM) considered here is based on the low energy SM gauge group together with an extra $Z'$ corresponding to an extra $U(1)_{N}$ gauge symmetry under which right--handed neutrinos have zero charge. The low energy matter content of the ESSM corresponds to three 27 representations of the $E_6$ symmetry group, to ensure anomaly cancellation, plus an additional pair of Higgs--li…
We point out that there are regions in the MSSM parameter space which successfully provide a dark matter (DM) annihilation explanation for observed positron excess (e.g. PAMELA), while still remaining in agreement with all other data sets. Such regions (e.g. the uplifted Higgs region) can realize an enhanced neutralino DM annihilation dominantly into leptons via a Breit-Wigner resonance through the CP-odd Higgs channel. Such regions can give the proper thermal relic DM abundance, and the DM annihilation products are compatible with current antiproton and gamma ray observations. This scenario c…
We work out the phenomenology of a model of supersymmetry breaking in the presence of a tiny (tunable) positive cosmological constant, proposed by the authors in arXiv:1403.1534. It utilises a single chiral multiplet with a gauged shift symmetry, that can be identified with the string dilaton (or an appropriate compactification modulus). The model is coupled to the MSSM, leading to calculable soft supersymmetry breaking masses and a distinct low energy phenomenology that allows to differentiate it from other models of supersymmetry breaking and mediation mechanisms.
The light Higgs mass in the MSSM is highly constrained and is predicted to be close to M_Z which causes a tension between the LEP II Higgs mass bound 114 GeV and the natural electroweak symmetry breaking in the MSSM. The usual way to increase the light CP even Higgs mass was to increase the quartic coupling of the up type Higgs. We point out that the light Higgs mass can be increased by reducing the off-diagonal term in the mass matrix when tan beta is moderate, which is about 5 to 10. As a result no mixing and/or a Higgs mixing angle of the opposite sign arises and the branching ratio of Higg…
I briefly review the physics of the Higgs sector in the Standard Model (SM) and its supersymmetric extension, in particular the MSSM, and discuss the prospects for discovering the Higgs particles at the Large Hadron Collider. Some emphasis will be put on the theoretical developments which occurred in the last few years.
We analyze the phenomenology of a set of minimal supersymmetric standard model (MSSM) soft terms inspired by flux-induced supersymmetry (SUSY)-breaking in Type IIB string orientifolds. The scheme is extremely constrained with essentially only two free mass parameters: a parameter M, which sets the scale of soft terms, and the mu parameter. After imposing consistent radiative electro-weak symmetry breaking (EWSB) the model depends upon one mass parameter (say, M). In spite of being so constrained one finds consistency with EWSB conditions. We demonstrate that those conditions have two solutions…
In this talk we will discuss how inflation can be embedded within a minimal extension of the Standard Model where the inflaton carries the Standard Model charges. There is no need of an ad-hoc scalar field to be introduced in order to explain the temperature anisotropy of the cosmic microwave background radiation, all the ingredients are present within a minimal supersymmetric Standard Model. For the first time inflaton properties can be directly linked to the particle phenomenology, dark matter, and the baryons of the Standard Model.
The R-parity non-conservation phenomenology within the minimal supersymmetric standard model with gauge mediated supersymmetry breaking has been studied. New constraints on the lepton number violating constant $λ_{111}^\prime$ were imposed by non-observability of the neutrinoless double beta decay. We find that $λ_{111}^\prime$ depends strongly on the effective supersymmetry breaking scale $Λ$ only and deduce limits which are much stronger than those previously found in literature.
We study neutralino sectors in extensions of the MSSM that dynamically generate the mu-term. The extra neutralino states are superpartners of the Higgs singlets and/or additional gauge bosons. The extended models may have distinct lightest neutralino properties which can have important influences on their phenomenology. We consider constraints on the lightest neutralino from LEP, Tevatron, and (g-2)_mu measurements and the relic density of the dark matter. The lightest neutralino can be extremely light and/or dominated by its singlino component which does not couple directly to SM particles ex…
We reanalyze the possibility of CP violation in the Higgs sector of the minimal supersymmetric standard model (MSSM). Contrary to the result of previous analysis, spontaneous CP violation can not occur by only chargino and neutralino radiative corrections since the vacuum does not stable. Top and stop radiative corrections are crucially needed. However even with this correction there is no experimentally allowed region in \tan β\geq 1. This situation is not remedied even if the stop left-right mixing is included. We also analyze explicit CP violation in the Higgs sector of the MSSM and show th…
We introduce a new confining force (μ-color) at TeV scale to dynamically generate a supersymmetry preserving mass scale which would replace the μparameter in the minimal supersymmetric standard model (MSSM). We discuss the Higgs phenomenology and also the pattern of soft supersymmetry breaking parameters allowing the correct electroweak symmetry breaking within the μ-color model, which have quite distinctive features from the MSSM and also from other generalizations of the MSSM.
We discuss the Higgs sector of the supersymmetric standard model extended by a gauge singlet for the range of parameters, which is compatible with universal soft supersymmetry breaking terms at the GUT scale. We present results for the masses, couplings and decay properties of the lightest Higgs bosons, in particular with regard to Higgs boson searches at LEP. The prospects differ significantly from the ones within the MSSM.
