Leptogenic Supersymmetry is a scenario characterized by copious lepton production in cascade decays. Due to the high lepton multiplicity and the lack of significant missing energy, leptogenic supersymmetry provides very clean channels which can be probed already with the early LHC data. Furthermore, the Higgs may be discovered in the h->b bbar mode because the leptons accompanying Higgs production efficiently suppress the background.
Leptogenic supersymmetry is a scenario characterized by cascade decays with copious lepton production. Leptogenic models have striking signatures that can be probed by the LHC even in the 10 TeV run with as little as 200 pb^-1 of data, provided the squark masses are about 1 TeV. Leptogenic supersymmetry spectrum arises in several well-motivated models and its signatures are long-lived sleptons, numerous isolated leptons, abundant Higgs production, rather energetic jets, and no missing energy. The Higgs can be discovered in the h->b bbar mode via the 4 leptons+4 jets channel because the leptons…
This talk discusses the prospects for supersymmetry studies at the LHC and NLC. The results are based on those of the Supersymmetry Working Group at the 1996 Snowmass Workshop.
The ATLAS collaboration published supersymmetry limits based on up to about 4.7 \ifb data collected over the year 2011 from LHC runs at 7 TeV. These were mainly interpreted within restricted, particular or simplified models for supersymmetry breaking schemes or scenarios. The pMSSM is an alternative and more generic supersymmetry framework which captures broader phenomenological features. Searching for more generic conclusions from the supersymmetry limits interpretation, we update a Bayesian global fit of the pMSSM to pre-LHC data using the LHC-7 limits. The posterior distributions show the m…
We show that the search for supersymmetry at LHC will be very problematic for the particular case of nonuniversal relations among gaugino masses. Namely, if gluino, first chargino and LSP masses are closed to each other it would be very difficult to discover supersymmetry even if sparticle masses are lighter than 1 TeV.
We update our analysis of the Higgs sector masses in Minimal Supersymmetry and in the Two-Higgs Doublet Model to the final ATLAS and CMS data from the 2011-2012 LHC run.
Supersymmetry is one of the best-motivated candidates for physics beyond the Standard Model that might be discovered at the LHC. There are many reasons to expect that it may appear at the TeV scale, in particular because it provides a natural cold dark matter candidate. The apparent discrepancy between the experimental measurement of g_mu - 2 and the Standard model value calculated using low-energy e+ e- data favours relatively light sparticles accessible to the LHC. A global likelihood analysis including this, other electroweak precision observables and B-decay observables suggests that the L…
The motivation for introduction of supersymmetry in high energy physics as well as a possibility for supersymmetry discovery at LHC (Large Hadronic Collider) are discussed. The main notions of the Minimal Supersymmetric Standard Model (MSSM) are introduced. Different regions of parameter space are analyzed and their phenomenological properties are compared. Discovery potential of LHC for the planned luminosity is shown for different channels. The properties of SUSY Higgs bosons are studied and perspectives of their observation at LHC are briefly outlined.
Prospects for SUSY discoveries and measurements at future colliders LHC and ILC are discussed. The problem of reconstructing the underlying theory and SUSY breaking mechanism is also addressed.
The prospects for the discovery and exploration of low-energy Supersymmetry at future colliders, the Large Hadron Collider (LHC) and the future international linear electron positron collider (ILC) are summarized. The focus is on the experimental techniques that will be used to discover superpartners and to measure their properties. Special attention is given to the question how the results from both machines could influence each other, in particular when they have overlapping running time.
We address the complementarity of the CERN Large Hadron Collider and an $e^+ e^-$ Linear Collider in determining SUSY model parameters for a particular SO(10) SUSY GUT case study.
If supersymmetry is broken at TeV scale, particles from sector responsible for supersymmetry breaking - goldstino and sgoldstinos - can reveal themselves already at the LHC experiments. We discuss bounds on supersymmetry breaking scale from the LHC searches for events with a jet plus missing momentum signature focusing on the case of TeV scale sgoldstinos. We show that contribution of light sgoldstinos to the cross section of of gravitino pair production with a jet can be sizable and the bounds on the gravitino mass can be stronger by up to a factor of 2 as compared to those obtained in the he…
Supersymmetry, a new symmetry that relates bosons and fermions in particle physics, still escapes observation. Search for SUSY is one of the main aims of the recently launched Large Hadron Collider. The other possible manifestation of SUSY is the Dark Matter in the Universe. The present lectures contain a brief introduction to supersymmetry in particle physics. The main notions of supersymmetry are introduced. The supersymmetric extension of the Standard Model - the Minimal Supersymmetric Standard Model - is considered in more detail. Phenomenological features of the MSSM as well as possible e…
At the LHC, superpartners with the masses lighter than a few TeV may be found, and the masses of the supersymmetric (SUSY) particles and their interactions will be studied. The information would be the base to consider the SUSY breaking mechanism and cosmology related to the SUSY dark matter. We review the recent studies that aims for the ``precise SUSY study'' at the LHC.
We investigate the implications for supersymmetry from an assumed absence of any signal in the first period of LHC data taking at 7 TeV center-of-mass energy and with 1 to 7 fb^(-1) of integrated luminosity. We consider the zero-lepton plus four jets and missing transverse energy signature, and perform a combined fit of low-energy measurements, the dark matter relic density constraint and potential LHC exclusions within a minimal supergravity model. A non-observation of supersymmetry in the first period of LHC data taking would still allow for an acceptable description of low-energy data and t…
These lectures, given at the 1997 TASI Summer School, describe the prospects for discovering supersymmetry (SUSY) and for studying its properties at the Large Hadron Collider (LHC) at CERN. If SUSY exists at a mass scale less than 1--2 TeV, then it should be easy to observe characteristic deviations from the Standard Model at the LHC. It is more difficult to determine SUSY masses because in most models there are two missing particles \tildeχ_1^0 in every event. However, it is possible to use various kinematic distributions to make precision measurements of combinations of SUSY masses and other…
If the minimal supersymmetric standard model is the solution to the hierarchy problem, the scalar top quark (stop) and the Higgsino should weigh around the electroweak scale such as 200 GeV. A low messenger scale, which results in a light gravitino, is also suggested to suppress the quantum corrections to the Higgs mass parameters. Therefore the minimal model for natural supersymmetry is a system with stop/Higgsino/gravitino whereas other superparticles are heavy. We study the LHC signatures of the minimal system and discuss the discovery potential and methods for the mass measurements.
Supersymmetry and extra dimensions are the two most promising candidates for new physics at the TeV scale. Supersymmetric particles or extra-dimensional effects could soon be observed at the Large Hadron Collider. We propose a simple but powerful method to discriminate the two models: the analysis of isolated leptons with high transverse momentum. Black hole events are simulated with the CATFISH black hole generator. Supersymmetry simulations use a combination of PYTHIA and ISAJET, the latter providing the mass spectrum. Our results show the measure of the dilepton invariant mass provides a st…
We consider the process of associated stop-chargino production in the MSSM at LHC and show that, at the simplest Born level, the production rate is dramatically sensitive to the choice of the benchmark points, oscillating from potentially "visible" maxima of the picobarn size to much smaller, hardly "visible", values. Adopting a canonical choice of SM type CKM matrices, we also show that in some "visible" cases the total rate exhibits a possibly relevant dependence on tan(beta).
We evaluate the supersymmetry reach of the Large Hadron Collider within the gauge-mediated low energy supersymmetry breaking framework, assuming that a neutralino is the second lightest sparticle and that it decays promptly into a gravitino which escapes detection. We find that the maximum reach is obtained via a search for inclusive $γγ+\eslt$ events coming dominantly from chargino and neutralino production. Assuming an integrated luminosity of 10~$fb^{-1}$, we find that LHC experiments will be able to probe values of the model parameter $Λ\alt 400$ TeV, corresponding to $m_{\tg} \leq 2.8$ Te…
Sneutrino-antisneutrino oscillation can be observed at the LHC by studying a charge asymmetry of the leptons in the final states. We demonstrate this in the context of an anomaly-mediated supersymmetry breaking model which can give rise to a large oscillation probability. The preferred region of the parameter space is characterized by the presence of a sneutrino next-to-lightest supersymmetric particle and a stau lightest supersymmetric particle. We show that the signals studied here have certain correlations with the pattern of the sneutrino oscillation.
We investigate squark and gluino pair production at LHC (CMS) with subsequent decays into quarks, leptons and LSP in models with effective supersymmetry where third generation of squarks is relatively light while the first two generations of squarks are heavy. We consider the general case of nonuniversal gaugino masses. Visibility of signal by an excess over SM background in $(n \geq 2)jets + (m \geq 0)leptons + E^{miss}_T$ events depends rather strongly on the relation between LSP, second neutralino, gluino and squark masses and it decreases with the increase of LSP mass.
ATLAS and CMS report indications of a Higgs boson at M_h 125 GeV. In addition, CMS data show a tenuous bump in the ZZ channel, at about 320 GeV. We make the bold assumption that it might be the indication of a secondary line corresponding to the heaviest scalar Higgs boson of Minimal Supersymmetry, H, and discuss the viability of this hypothesis. We discuss also the case of a heavier H, the relevance of the b bbar decay channel is underlined.
The prospects for discovering neutral Higgs bosons in the minimal supersymmetric model (MSSM) and in the minimal supergravity model at the LHC are investigated. Two special discovery channels are discussed: (i) the decay mode of the MSSM CP-odd Higgs boson into photon pairs, and (ii) the decays of neutral Higgs bosons into muon pairs in the MSSM as well as in the minimal supergravity model.
Sneutrino-antisneutrino oscillation can be observed at the LHC by studying a charge asymmetry of the leptons in the final states. In this talk, we demonstrate this in the context of an anomaly-mediated supersymmetry breaking model which can give rise to a large oscillation probability. The preferred region of the parameter space is characterized by the presence of a sneutrino next-to-lightest supersymmetric particle and a stau lightest supersymmetric particle. We show that the signals studied here have certain correlations with the pattern of the sneutrino oscillation.
The discovery potential of the LHC is investigated for the minimal anomaly-mediated supersymmetry breaking (mAMSB) scenario, using the ATLAS fast detector simulator, including track reconstruction and particle identification. Generic supersymmetry search cuts are used to map the 5-sigma (and >=10 event) discovery contours in the m_0 - m_3/2 plane. With 100 inverse fb of integrated luminosity the search will reach up to 2.8 TeV in the squark mass and 2.1 TeV in the gluino mass. We generalise a kinematical variable and demonstrate that it is sensitive to the small chargino-LSP mass splitting cha…
In this thesis we examine three different models in the MSSM context, all of which have significant supergravity anomaly contributions to their soft masses. These models are the so-called Minimal, Hypercharged, and Gaugino Anomaly Mediated Supersymmetry Breaking models. We explore some of the string theoretical motivations for these models and proceed by understanding how they would appear at the Large Hadron Collider (LHC). Our major results include calculating the LHC reach for each model's parameter space and prescribing a method for distinguishing the models after the collection of 100 fb^…
Coherent analyses of experimental results from LHC and ILC will allow us to draw a comprehensive and precise picture of the supersymmetric particle sector. Based on this platform the fundamental supersymmetric theory can be reconstructed at the high scale which is potentially close to the Planck scale. This procedure will be reviewed for three characteristic examples: minimal supergravity as the paradigm; a left-right symmetric extension incorporating intermediate mass scales; and a specific realization of string effective theories.
The determination of supersymmetric parameters at the LHC in favorable as well as difficult scenarios is presented. If discovered and measured at the LHC and the ILC, supersymmetry may provide a link between collider physics and cosmology.
We present an extensive analysis of gauge-mediated supersymmetry breaking models with minimal and non-minimal flavour violation. We first demonstrate that low-energy, precision electroweak, and cosmological constraints exclude large "collider-friendly" regions of the minimal parameter space. We then discuss various possibilities how flavour violation, although naturally suppressed, may still occur in gauge-mediation models. The introduction of non-minimal flavour violation at the electroweak scale is shown to relax the stringent experimental constraints, so that benchmark points, that are also…
If SUSY is discovered at the LHC, the task will immediately turn to determining the model of SUSY breaking. Here, we employ a Mixed Modulus-Anomaly Mediated SUSY Breaking (MMAMSB) model with very similar LHC phenomenology to the more conventionally studied Constrained Minimal SUSY Model (CMSSM) and minimal Anomaly Mediated SUSY Breaking (mAMSB) models. We then study whether the models can be distinguished and measured. If we only fit to the various mass edges and mass end-points from cascade decay chains that are normally studied, a unique determination and measurement of the model is problema…
We consider the generalized gauge mediated supersymmetry breaking (GMSB) models with the messenger fields which do not form the complete multiplets of SU(5) GUT symmetry. Such a situation may happen in the anomalous U(1) GUT scenario because the mass spectrum of the superheavy particle does not respect SU(5) GUT symmetry, although the success of the gauge coupling unification can be explained. In this paper, we assume that one pair of the messenger fields gives the dominant contribution, and the LHC signature for the two possible messengers, X + \bar{X} and Q + \bar{Q}, are examined. We invest…
The study of the Higgs boson properties offers compelling perspectives for testing the effects of physics beyond the Standard Model and has deep implications for the LHC program and future colliders. Accurate determinations of the Higgs boson properties can provide us with a distinctively precise picture of the Higgs sector, set tight bounds, and predict ranges for the values of new physics model parameters. In this paper, we discuss the constraints on supersymmetry that can be derived by a determination of the Higgs boson mass and couplings. We quantify these constraints by using scans of the…
We analyse hadronically quiet trilepton signatures in the T-parity conserving Littlest Higgs model and in R-parity conserving supersymmetry at the Large Hadron Collider. We identify the regions of the parameter space where such signals can reveal the presence of these new physics models above the Standard Model background and distinguish them from each other, even in a situation when the mass spectrum of the Littlest Higgs model resembles the supersymmetric pattern.
We study the most general extension of the MSSM Lagrangian that includes scenarios in which supersymmetry is spontaneously broken at a low scale f. The spurion that parametrizes supersymmetry breaking in the MSSM is promoted to a dynamical superfield involving the goldstino, with (and without) its scalar superpartner, the sgoldstino. The low energy effective Lagrangian is written as an expansion in terms of m_{SUSY}/sqrt{f}, where m_{SUSY} is the induced supersymmetry breaking scale, and contains, in addition to the usual MSSM Lagrangian with the soft terms, couplings involving the component f…
An important tool for interpreting LHC searches for new physics are simplified models. They are characterized by a small number of parameters and thus often rely on a simplified description of particle production and decay dynamics. Considering the production of squarks of the first two generations we compare the interpretation of current LHC searches for hadronic jets plus missing energy signatures within simplified models with the interpretation within a complete supersymmetric model. Although we find sizable differences in the signal efficiencies, in particular for large supersymmetric part…
We consider a search strategy for new physics at the Large Hadron Collider which focuses on the signature of many jets and missing transverse energy, but no charged leptons. We show that this signature can be useful in probing a wide class of models, including natural supersymmetry, in which dark matter is produced in conjunction top quarks. As an example, we apply this strategy to a simplified supersymmetric model with a light gluino, light stop and light neutralino. The efficacy of this strategy is comparable to (and in some cases better than) that of other strategies which require charged l…
We elaborate on a recently found SU(5) relation confined to the up-(s)quark flavour space, that remains immune to large quantum corrections up to the TeV scale. We investigate the possibilities opened by this new window on the GUT scale in order to find TeV-scale SU(5) tests realizable at the LHC. These SU(5) tests appear as relations among observables involving either flavour violation or chirality flip in the up-(s)quark sector. The power of these tests is systematically evaluated using a frequentist, p-value based criterion. SU(5) tests in the Heavy supersymmetry (SUSY), Natural supersymmet…
At the LHC and at an ILC, serious studies of new physics benefit from a proper simulation of signals and backgrounds. Using supersymmetric sbottom pair production as an example, we show how multi-particle final states are necessary to properly describe off-shell effects induced by QCD, photon radiation, or by intermediate on-shell states. To ensure the correctness of our findings we compare in detail the implementation of the supersymmetric Lagrangian in MadGraph, Sherpa and Whizard. As a future reference we give the numerical results for several hundred cross sections for the production of su…
We present a re-interpretation of the recent ATLAS limits on supersymmetry in channels with jets (with and without b-tags) and missing energy, in the context of light third family squarks, while the first two squark families are inaccessible at the 7 TeV run of the Large Hadron Collider (LHC). In contrast to interpretations in terms of the high-scale based constrained minimal supersymmetric standard model (CMSSM), we primarily use the low-scale parametrisation of the phenomenological MSSM (pMSSM), and translate the limits in terms of physical masses of the third family squarks. Side by side, w…
The inclusion of trilinear R-parity violating couplings in a supersymmetric theory, has monumental impacts on the phenomenology. Regarding LHC physics, we no longer expect events with a lot of missing transverse energy, but events with large lepton and/or jet multiplicity. Here we present a study where the standard MSSM scenario of squark and gluino pair production and consequent cascade decay to the neutralino, is followed by a three-body decay of the neutralino through any of the 45 allowed trilinear R-parity violating operators. This allows us to study all these operators and detect any hie…
We consider an extension of the MSSM with an added vectorlike top partner. Our aim is to revisit to what extent such an extension can raise the Higgs boson mass through radiative corrections and help ameliorate the MSSM hierarchy problem, and to specify what experimental probes at the LHC will find or exclude this possibility during the high-luminosity phase. Direct detection, precision electroweak and precision Higgs analyses are all commissioned to this end. To achieve the $ 125 \, \textrm{GeV} \ $ Higgs boson mass, we find that superpartner masses can be reduced by a factor of more than thr…
The strong constraints on the R-parity conserving supersymmetry (SUSY) from the LHC searches motivate us to consider the new models in which the low-scale SUSY is still allowed. We propose a kind of R-parity violating SUSY scenarios with a non-zero $U^c_2 D^c_2 D^c_3$ operator. Three relevant LHC searches are recasted to test the status of this scenario in terms of four simplified models, with either light stop-Bino, stop-Higgsino, sbottom-Bino or sbottom-Higgsino. Some difficult scenarios for the LHC SUSY searches in these simplified models are identified. By extrapolate the current LHC searc…
We investigate squark and gluino pair production at LHC (CMS) with subsequent decays into quarks, leptons and LSP in models with effective supersymmetry where third generation of squarks is relatively light while the first two generations of squarks are heavy. We consider the general case of nonuniversal gaugino masses. Visibility of signal by an excess over SM background in (n \geq 2)jets + (m \geq 0)leptons + E^{miss}_T events depends rather strongly on the relation between LSP, second neutralino, gluino and squark masses and it decreases with the increase of LSP mass. We find that for relat…
Supersymmetric theories which can allow for a 125 GeV Higgs mass and also solve the naturalness and susy flavor problems now require a fair degree of complexity. Here we consider the simplest possibility for supersymmetry near the weak scale, but with the requirement of naturalness dropped. In "pure gravity mediation", all supersymmetric particles except for the gauginos lie at tens to thousands of TeV, with the gauginos obtaining loop suppressed masses automatically by anomaly mediation and higgsino threshold corrections. The gauginos are the lightest superpartners, and we investigate the cur…
If supersymmetry is discovered at the LHC, the next question will be the determination of the underlying model. While this may be challenging or even intractable, a more optimistic question is whether we can understand the main contours of any particular paradigm of the mediation of supersymmetry breaking. The determination of superpartner masses through endpoint measurements of kinematic observables arising from cascade decays is a powerful diagnostic tool. In particular, the determination of the gaugino sector has the potential to discriminate between certain mediation schemes (not all schem…
The resonant production of sneutrinos at the LHC via the R-parity violating couplings $ł'_{ijk} L_i Q_j D^c_k$ is studied through its three-leptons signature. A detailed particle level study of signal and background is performed using a fast simulation of the ATLAS detector. Through the full reconstruction of the cascade decay, a model-independent and precise measurement of the masses of the involved sparticles can be performed. Besides, this signature can be detected for a broad class of supersymmetric models, and for a wide range of values of several $ł'_{ijk}$ coupling constants. Within the…
Given that it will take quite some time for the Large Hadron Collider (LHC) to reach its desired luminosity, it is important to investigate the most favorable scenario in which supersymmetry (SUSY) may be discovered at the early runs at the LHC. Our aim in this work is to find such a scenario within the gravity mediated SUSY breaking (SUGRA) framework and select a class of final states that warrant a discovery at the very early runs of the LHC. It turns out that such a situation can be associated with a scenario where gluinos are sufficiently light and so are the third generation scalars while…
We analyze the LHC phenomenology of lambdaSUSY - a version of NMSSM with a largish SH1H2 coupling. The scalar spectrum of the model contains a 200-300 GeV Higgs boson h with Standard-Model like properties, and heavy CP-even and CP-odd Higgs bosons H and A with masses in 500-800 GeV range. We study the discovery potential of H and A in the decay chains H->hh->4V->2l6j and A->Zh->Z2V->2l4j. The dominant backgrounds are the diffuse Z6j and Z4j productions, which can be suppressed by demanding reconstruction of V's and h's in intermediate states. The excess of signal events allows for a discovery …
Both ATLAS and CMS have published results of SUSY searches putting limits on SUSY parameters and masses. A non-discovery of SUSY in the next two years would push these limits further. On the other hand, precision data of low energy measurements and the dark matter relic density favor a light scale of supersymmetry. Therefore we investigate if supersymmetry -- more specifically the highly constraint model mSUGRA -- does at all agree with precision data and LHC exclusions at the same time, and whether the first two years of LHC will be capable of excluding models of supersymmetry. We consider th…
This review surveys the territory of supersymmetry beyond the vanilla MSSM. With a viewpoint guided by electroweak naturalness, the review focuses on constructions that weaken or bypass current LHC constraints. Models of SUSY containing Dirac gluinos, compressed spectra, flavor-violating squarks, R-parity violation, stealth sectors, exotic detector objects, and more are discussed. In addition to presenting ways of hiding SUSY, these models highlight a few opportunities to improve LHC coverage.
Characteristic examples are presented of scenarios of particle production and decay in supersymmetry models in which the supersymmetry breaking is transmitted to the observable world via gauge interactions. The cases are chosen to illustrate the main classes of LHC phenomenology that can arise in these models. A new technique is illustrated that allows the full reconstruction of supersymmetry events despite the presence of two unobserved particles. This technique enables superparticle masses to be measured directly rather than being inferred from kinematic distributions. It is demonstrated tha…
The suppression of flavor and CP violation in supersymmetric theories may be due to the mechanism responsible for the structure of the Yukawa couplings. We study model independently the compatibility between low energy flavor and CP constraints and observability of superparticles at the LHC, assuming a generic correlation between the Yukawa couplings and the supersymmetry breaking parameters. We find that the superpotential operators that generate scalar trilinear interactions are generically problematic. We discuss several ways in which this tension is naturally avoided. In particular, we foc…
The prospects of detecting the CP-odd Higgs pseudoscalar ($A$) in the minimal supersymmetric model via its decay into a $Z$ boson and the lighter CP-even Higgs scalar ($h$) at the CERN Large Hadron Collider are investigated. The final state of $Z \to l^+l^-$ and $h \to b\bar{b}$, may provide a promising way to simultaneously detect the $A$ and the $h$. The compact muon solenoid detector performance is adopted for a realistic study of observability. In this discovery channel, the masses of the $h$ and the $A$ can be reconstructed. The impact of supersymmetric decay modes is considered.
The kind of supersymmetry that can be discovered at the LHC must be very much flavor-blind, which used to require very special intelligently designed models of supersymmetry breaking. This led to the pessimism for some in the community that it is not likely for the LHC to discover supersymmetry. I point out that this is not so, because a garden-variety supersymmetric theories actually can do this job.
We studied the extension of Standard Model (SM) Higgs sector with $SU(2)$ triplet and SM gauge singlet in the context of supersymmetry. For a $Z_3$ symmetric superpotential where the singlet field generates the bi-linear Higgs mixing term between two Higgs doublets dynamically. Models like this often have a very light pseudoscalar as pseudo-Nambu Goldstone model of an extra $U(1)$ symmetry. We investigate the possibility of such light hidden Higgs boson with the data of the discovered Higgs boson around 125 GeV. Along with the neutral sector, the charged Higgs bosons in the triplet extended ca…
If supersymmetry is discovered at the LHC, the measured spectrum of superpartner masses and couplings will allow us to probe the origins of supersymmetry breaking. However, to connect the collider-scale Lagrangian soft parameters to the more fundamental theory from which they arise, it is usually necessary to evolve them to higher scales. The apparent unification of gauge couplings restricts the possible forms of new physics above the electroweak scale, and suggests that such an extrapolation is possible. Even so, this task is complicated if the low scale spectrum is not measured completely or…
Naturalness bounds on weak scale supersymmetry in the context of radiative breaking of the electro-weak symmetry are analyzed. In the case of minimal supergravity it is found that for low tanβand for low values of fine tuning Phi, where Phi is defined essentially by the ratio μ^2/M_Z^2 where μis the Higgs mixing parameter and M_Z is the Z boson mass, the allowed values of the universal scalar parameter m_0, and the universal gaugino mass m_{1/2} lie on the surface of an ellipsoid with radii fixed by Φleading to tightly constrained upper bounds \sim \sqrtΦ.Thus for tanβ\leq 2(\leq 5) it is foun…
