We investigate the phenomenological consequences of string models wherein the MSSM resides on a D-brane, and the hypercharge gaugino mass is generated in a geometrically separated hidden sector. This hypercharged anomaly-mediated SUSY breaking (HCAMSB) model naturally solves the tachyonic slepton mass problem endemic to pure AMSB scenarios. In HCAMSB, one obtains a mass ordering M_1>μ>M_2 with split left- and right- scalars, whereas in mAMSB models, one obtains μ>M_1>M_2 with nearly degenerate left- and right-scalars. We compute the allowed parameter space and expected superparticle mass spectrum in the HCAMSB model. For low values of the HC and AMSB mixing parameter α, the spectra is characterized by light left-sleptons, while the spectra for large αis characterized by light top- and bottom- squarks. We map out the approximate reach of LHC for HCAMSB, and find that with 100 fb^{-1} of integrated luminosity, a gravitino mass of \sim 115 (105) TeV can be probed for low (high) values of α, corresponding to a gluino mass reach of \sim 2.4 (2.2) TeV. Both cases contain-- as is typical in AMSB models-- long lived charginos that should yield visible highly ionizing tracks in the LHC detector. Also, in the lower \tanβrange, HCAMSB models give rise to reconstructable Z\to \ell\bar{\ell} candidates in SUSY cascade decay events, while mAMSB models should do so only rarely.
Supersymmetric models based on anomaly-mediated SUSY breaking (AMSB) generally give rise to a neutral wino as a WIMP cold dark matter (CDM) candidate, whose thermal abundance is well below measured values. Here, we investigate four scenarios to reconcile AMSB dark matter with the measured abundance: 1. non-thermal wino production due to decays of scalar fields ({\it e.g} moduli), 2. non-thermal wino production due to decays of gravitinos, 3. non-thermal wino production due to heavy axino decays, and 4. the case of an axino LSP, where the bulk of CDM is made up of axions and thermally produced …
New studies of the ATLAS and CMS collaborations are presented on the sensitivity to searches for non-standard signatures of particular SUSY scenarios. These signatures include non-pointing photons, as well as pairs of prompt photons, as expected in GMSB SUSY models, as well as heavy stable charged particles produced in split supersymmetry models, long lived staus from GMSB SUSY and long lived stops in other SUSY scenarios. A detailed detector simulation is used for the study, and all relevant Standard Model backgrounds and detector effects that can mimic these special signatures are included. …
In this talk, prospects for the charged Higgs in non-SUSY models are reviewed, in view of LHC results (as of October, 2012). The four models (Type I, Type II, lepton-specific and flipped) without tree level flavor-changing neutral currents are discussed. Updates for the case in which the charged Higgs is lighter than the top, leading to production in top decays, are presented along with expectations for the future. If the charged Higgs is heavier than the top quark, detection may be possible through the tau-nu decay mode. In addition, it is pointed out that the decay of the charged Higgs into …
We analyze constraints on the parameters of the R-parity violating supersymmetry which can be extracted from non-observation of the neutrinoless nuclear double beta decay ($0νββ$) at a given half-life lower bound. Our analysis covers a large class of phenomenologically viable R-parity violating SUSY models. We introduce special characteristics: the SUSY sensitivity of a $ββ$ decaying isotope and the SUSY reach of a $0νββ$ experiment. The former provides a physical criterion for a selection of the most promising isotopes for SUSY searches and the latter gives a measure of success for a $0νββ$ e…
Discussions are underway for a high-energy proton-proton collider. Two preliminary ideas are the $\sqrt{s}=33$ TeV HE-LHC and the $\sqrt{s}=100$ TeV VLHC. With Bayesian statistics, we calculate the probabilities that the LHC, HE-LHC and VLHC discover SUSY in the future, assuming that nature is described by the CMSSM and given the experimental data from the LHC, LUX and Planck. We find that the LHC with $300$/fb at $\sqrt{s}=14$ TeV has a $15$-$75%$ probability of discovering SUSY. Should that run fail to discover SUSY, the probability of discovering SUSY with $3000$/fb is merely $1$-$10%$. Wer…
We examine production and decay of heavy neutral SUSY Higgs bosons pp-> H,\ A -> τ\barτ within the hMSSM and compare against a perhaps more plausible natural supersymmetry scenario dubbed m_h^{125}({\rm nat}) which allows for a natural explanation for m_{weak}\simeq m_{W,Z,h}\sim 100 GeV while maintaining m_h\simeq 125 GeV. We evaluate signal against various Standard Model backgrounds from γ,Z ->τ\barτ, t\bar{t} and vector boson pair production VV. We combine the transverse mass method for back-to-back (BtB) taus along with the ditau mass peak m_{ττ} method for acollinear taus as our signal ch…
In the post-LHC8 world-- where a Standard Model-like Higgs boson has been established but there is no sign of supersymmetry (SUSY)-- the detailed profiling of the Higgs boson properties has emerged as an important road towards discovery of new physics. We present calculations of the expected deviations in Higgs boson couplings $κ_{τ,b}$, $κ_t$, $κ_{W,Z}$, $κ_g$ and $κ_γ$ versus the naturalness measure $Δ_{\rm EW}$. Low values of $Δ_{\rm EW}\sim 10-30$ give rise to a natural Little Hierarchy characterized by light higgsinos with a mass of $μ\sim m_Z$ while top squarks are highly mixed but lie i…
We give detailed predictions for diffractive SUSY Higgs boson and top squark associated productions at the LHC via the exclusive double pomeron exchange mechanism. We study how the SUSY Higgs cross section and the signal over background ratio are enhanced as a function of tangent beta in different regimes. The prospects are particularly promising in the ``anti-decoupling'' regime, which we study in detail. We also give the prospects for a precise measurement of the top squark mass using the threshold scan of central diffractive associated top squark events at the LHC.
An electroweak (EW) sector of the Minimal Supersymmetric Standard Model (MSSM) with masses of a few hundred GeV can account for variety of experimental data, assuming the lightest neutralino to be the lightest supersymmetric (SUSY) particle: the non-observation at the LHC searches owing to their small production cross sections, the results for the (upper limit of the) Dark Matter (DM) relic abundance and the DM Direct Detection (DD) limits. Such a light EW sector can in particular explain the reinforced $4.2\,σ$ discrepancy between the experimental result for $(g-2)_μ$, and its Standard Model …
We perform a study of the impact of the recently released limits on BR(Bs -> mu+ mu-) by LHCb and CMS on several SUSY models. We show that the obtained constraints can be superior to those which are derived from direct searches for SUSY particles in some scenarios, and the use of a double ratio of purely leptonic decays involving Bs -> mu+ mu- can further strengthen such constraints. We also discuss the experimental sensitivity and prospects for observation of Bs -> mu+ mu- during the sqrt(s)=7 TeV run of the LHC, and its potential implications.
We explore supersymmetry (SUSY) parameter space with non-universal high scale parameters in gravity mediated SUSY breaking (SUGRA) scenario that accommodates a Higgs mass of (125$\pm$2) GeV while satisfying cold dark matter relic density and other low energy constraints. We indicate a few benchmark points consistent with different dark matter annihilation processes where third family squarks are lighter than the first two as a requirement to keep the Higgs mass within the limit. We show that bottom rich and leptonic final states have better reach in such parameter space points and is the most …
The ATLAS and CMS experiments will take first data soon. I consider here the prospects for new physics (excluding SUSY) with a few inverse fb of data. This means processes with signal cross sections of a few 100 fb or less, with clear and fairly simple signatures - precision comparison of data to Standard Model tails will take longer, needing more luminosity and very good understanding of detector calibrations, resolutions and trigger efficiencies. The approach I take here is signature rather than model based, but examples of models will be given.
Given the recent progress in dark matter direction detection experiments, we examine a light bino-higgsino dark matter (DM) scenario ($M_1<100$ GeV and $μ<300$ GeV) in natural supersymmetry with the electroweak fine tuning measure $Δ_{EW}<30$. By imposing various constraints, we note that: (i) For $sign(μ/M_1)=+1$, the parameter space allowed by the DM relic density and collider bounds can almost be excluded by the very recent spin-independent (SI) scattering cross section limits from the XENON1T (2017) experiment. (ii) For $sign(μ/M_1)=-1$, the SI limits can be evaded due to the cancelation e…
In this talk I review the motivations for physics beyond the Standard Model at the TeV scale and the prospects for their detection in the second Run of LHC. Then I focus in the supersymmetric case, paying special attention to the formulation and implications of the Natural SUSY scenario.
We present a preliminary study on the possibility to search for massive long-lived electrically charged particles at the MoEDAL detector. MoEDAL is sensitive to highly ionising objects such as magnetic monopoles or massive (meta-)stable electrically charged particles and we focus on the latter in this paper. Requirements on triggering or reducing the cosmic-ray and cavern background, applied in the ATLAS and CMS analyses for long-lived particles, are not necessary at MoEDAL, due to its completely different detector design and extremely low background. On the other hand, MoEDAL requires slow-mo…
The requirement of t-b-τYukawa coupling unification is common in simple grand unified models based on the gauge group SO(10), and it also places a severe constraint on the expected spectrum of superpartners. For Yukawa-unified models with μ>0, the spectrum is characterized by three mass scales: {\it i}). first and second generation scalars in the multi-TeV range, {\it ii}). third generation scalars, μand m_A in the few-TeV range and {\it iii}). gluinos in the \sim 350-500 GeV range with chargino masses around 100-160 GeV. In such a scenario, gluino pair production should occur at large rates a…
We investigate the prospects for the discovery of a neutral Higgs boson produced in association with a $b$ quark, followed by the Higgs decay into a pair of bottom quarks, $pp \to bϕ^0 \to b b\bar{b} +X$, at the CERN Large Hadron Collider (LHC) within the framework of unified supersymmetric models. The Higgs boson $ϕ^0$ can be a heavy scalar $H^0$ or a pseudoscalar $A^0$. Furthermore, this direct discovery channel is compared with the indirect Higgs searches in the rare decay $B_s \to μ^+μ^-$ at hadron colliders. Promising results are found for the minimal supergravity (mSUGRA) model, the anom…
Under the expectation that nature is natural, we extend the Standard Model to include SUSY to stabilize the electroweak sector and PQ symmetry to stabilize the QCD sector. Then natural SUSY arises from a Kim-Nilles solution to the SUSY mu problem which allows for a little hierarchy where mu ~ f_a^2/M_P ~ 100-300 GeV while the SUSY particle mass scale m(SUSY)~ 1-10 TeV >> mu. Dark matter then consists of two particles: a higgsino-like WIMP and a SUSY DFSZ axion. The range of allowed axion mass values m(axion) depends on the mixed axion-higgsino relic density. The range of m(axion) is actually r…
Motivated by recent progress in experimental techniques of electric dipole moment (EDM) measurements, we study correlations between the neutron and electron EDMs in common supersymmetric models. These include minimal supergravity (mSUGRA) with small CP phases, mSUGRA with a heavy SUSY spectrum, the decoupling scenario and split SUSY. In most cases, the electron and neutron EDMs are found to be observable in the next round of EDM experiments. They exhibit certain correlation patterns. For example, if d_n ~ 10^{-27} e cm is found, d_e is predicted to lie in the range 10^{-28}-10^{-29} e cm.
The lack of a new physics signal thus far at the Large Hadron Collider motivates us to consider how to look for challenging final states, with large Standard Model backgrounds and subtle kinematic features, such as cascade decays with compressed spectra. Adopting a benchmark SUSY-like decay topology with a four-body final state proceeding through a sequence of two-body decays via intermediate resonances, we focus our attention on the kinematic variable $Δ_{4}$ which previously has been used to parameterize the boundary of the allowed four-body phase space. We highlight the advantages of using …
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.
The discovery of the Higgs boson along with the vigorous confirmation of the SM coupled with non-appearance of new (SUSY) particles has led to an apparent naturalness crisis. We argue the crisis stems from overestimates of finetuning. A proper evaluation of naturalness in SUSY leads to light higgsinos with mass mu~ 100-300 GeV while other sparticles may inhabit the multi-TeV range at little cost to naturalness. Special signatures like dilepton mass edges in gluino pair events and same-sign dibosons from wino pairs might occur at LHC13. An ILC with \sqrt{s}>2 mu would make the definitive test o…
Muon g-2 anomaly, which is mismatch between the theoretical and the experimental values of the anomalous magnetic moment of muons, provides a sensitive probe of new physics. In SUSY, if masses of the superpartners relevant to the muon g-2 are O(100) GeV, the SUSY contributions to the muon g-2 become sizable and the anomaly can be solved. There are two representative SUSY contributions to the muon g-2, the chargino and the neutralino contributions, respectively. Particularly, when the discrepancy of the muon g-2 is dominated by the neutralino contributions, it is found that the discrepancy can …
Non-decoupling D-term extensions of the MSSM enhance the tree-level Higgs mass compared to the MSSM, therefore relax fine-tuning and may allow lighter stops with rather low masses even without maximal mixing. We present the anatomy of various non-decoupling D-term extensions of the MSSM and explore the potential of the LHC and of the International Linear Collider (ILC) to determine their deviations in the Higgs couplings with respect to the Standard Model. Depending on the mass of the heavier Higgs $m_H$, such deviations may be constrained at the LHC and determined at the ILC. We evaluate the …
We study SUSY signatures at the 7, 8 and 14 TeV LHC employing the 19-parameter, R-Parity conserving p(henomenological)MSSM, in the scenario with a neutralino LSP. Our results were obtained via a fast Monte Carlo simulation of the ATLAS SUSY analysis suite. The flexibility of this framework allows us to study a wide variety of SUSY phenomena simultaneously and to probe for weak spots in existing SUSY search analyses. We determine the ranges of the sparticle masses that are either disfavored or allowed after the searches with the 7 and 8 TeV data sets are combined. We find that natural SUSY mode…
Recent results on MSSM Higgs physics at the LHC are reviewed. The dependence of the LHC discovery reach in the b\bar b H/A, H/A \to τ^+τ^- channel on the underlying SUSY scenario is analysed. This is done by combining the latest results for the prospective CMS experimental sensitivities for an integrated luminosity of 30 or 60 fb^-1 with state-of-the-art theoretical predictions of MSSM Higgs-boson properties. The results are interpreted in terms of the parameters governing the MSSM Higgs sector at lowest order, M_A and tan_beta. While the higgsino mass parameter μhas a significant impact on th…
On the basis of frequentist analyses of experimental constraints from electroweak precision data, (g-2)_mu, B-physics and cosmological data, we predict the masses of Higgs bosons and SUSY particles of the CMSSM, NUHM1, VCMSSM and mSUGRA. In the CMSSM, NUHM1 and VCMSSM we find preferences for sparticle masses that are relatively light, leading to good prospects for the LHC and the ILC. Including first data from SUSY searches at the LHC leads to an increase of the preferred sparticle mass scales, but improves the consistency of the model predictions for M_h with the LEP exclusion bounds.
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.
Working within the framework of the minimal supergravity model with gauge coupling unification and radiative electroweak symmetry breaking (SUGRA), we map out regions of parameter space explorable by experiments at LEP2, for center of mass energy options of $\sqrt{s}=150,\ 175$, $190$ and 205 GeV. We compute signals from all accessible $2 \rightarrow 2$ SUSY pair production processes using the ISAJET simulation program, and devise cuts that enhance the signal relative to Standard Model backgrounds, and which also serve to differentiate various supersymmetric processes from one another. We deli…
Natural SUSY scenarios with a low value of the $μ$ parameter, are characterised by a higgsino-like dark matter candidate, and a compressed spectrum for the lightest higgsinos. We explore the prospects for probing this scenario at the 13 TeV stage of the LHC via monojet searches, with various integrated luminosity options, and demonstrate how these results are affect by different assumptions on the achievable level of control on the experimental systematic uncertainties. The complementarity between collider and direct detection experiments (present and future) is also highlighted.
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…
We examine the supersymmetry phenomenology of a novel scenario of supersymmetry (SUSY) breaking which we call Gaugino Anomaly Mediation, or inoAMSB. This is suggested by recent work on the phenomenology of flux compactified type IIB string theory. The essential features of this scenario are that the gaugino masses are of the anomaly-mediated SUSY breaking (AMSB) form, while scalar and trilinear soft SUSY breaking terms are highly suppressed. Renormalization group effects yield an allowable sparticle mass spectrum, while at the same time avoiding charged LSPs; the latter are common in models wi…
The ability of the LHC to make statements about the dark matter problem is considered, with a specific focus on supersymmetry. After reviewing the current strategies for supersymmetry searches at the LHC (in both CMS and ATLAS), some key ATLAS studies are used to demonstrate how one could establish that SUSY exists before going on to measure the relic density of a neutralino WIMP candidate. Finally, the general prospects for success at the LHC are investigated by looking at different points in the MSSM parameter space.
We discuss the potential to observe effects of CP violation in squark decay chains at the LHC. As the CP-violating observable we use the asymmetry composed by triple products of final state momenta. Extending methods for momentum reconstruction we show that there are good prospects for observation of these effects at the LHC. Finally, we include the main experimental factors and discuss the expected sensitivity.
The realization that supersymmetry (SUSY), if softly broken at the weak scale, can stabilize the Higgs sector led many authors to explore the role it may play in particle physics. It was widely anticipated that superpartners would reveal themselves once the TeV scale was probed in high energy collisions. Experiments at the LHC have not yet revealed any sign for direct production of superpartners, or for any other physics beyond the Standard Model. This has led to some authors to question whether weak scale SUSY has a role to play in stabilizing the Higgs sector. We show that SUSY models with j…
We consider the possibility that the muon g-2 anomaly, $δ(g-2)$, finds its origins in low energy supersymmetry (SUSY). In the general MSSM the parameter space consistent with $δ(g-2)$ and correct dark matter relic density of the lightest neutralino easily evades the present direct LHC limits on sparticle masses and also lies to a large extent beyond future LHC sensitivity. The situation is quite different in GUT-defined scenarios where input SUSY parameters are no longer independent. We analyze to what extent the LHC can probe a broad class of GUT-inspired SUSY models with gaugino non-universa…
In this talk, we discuss the SUSY-Yukawa sum rule, a relation among masses and mixing angles of the third-generation squarks which follows directly from the coupling relation responsible for canceling the quadratic divergence in the Higgs mass. Radiative corrections modify the sum rule, introducing dependence on a variety of SUSY parameters beyond the third-generation squark sector. If some of those parameters are measured experimentally, a sharp prediction for the sum rule is possible. We demonstrate this point with a quantitative study. We also discuss the prospects for measuring the ingredi…
As we anticipate the first results of the 2016 run, we assess the discovery potential of the LHC to `natural supersymmetry'. To begin with, we explore the region of the model parameter space that can be excluded with various centre-of-mass energies (13 TeV and 14 TeV) and different luminosities (20 fb$^{-1}$, 100 fb$^{-1}$, 300 fb$^{-1}$ and 3000 fb$^{-1}$). We find that the bounds at 95% CL on stops vary from $m_{\tilde{t}_1}\gtrsim 900$ GeV expected this summer to $m_{\tilde{t}_1}\gtrsim 1500$ GeV at the end of the high luminosity run, while gluino bounds are expected to range from $m_{\tild…
I review proton decay in the SUSY SU(5) GUTs assuming the mini-split SUSY breaking model. In the mini-split SUSY breaking model, the squark and slepton masses are O(10^{(2-3)}) TeV while the gaugino masses are O(1) TeV. As the result, even the minimal SUSY SU(5) GUT is still viable in the model. We present the motivation of the mini-split SUSY model and discuss the future prospects of proton decay searches in the SUSY SU(5) GUTs.
We look at the possibility of non-perturbative particle production after inflation from SUSY flat directions produced by rotating eigenstates thereby avoiding the standard adiabaticity conditions. This might lead to preheating and prevent the delay of thermalisation of the universe. We investigate the flat directions $LLE^c$ and $U^cD^cD^c$ and find no particle production. These 2 directions are very important, since they have been named as possible candidates for being the inflaton. We investigate $QLQLQLE^c$ and find particle production and therefore the possibility of preheating. We investi…
We perform a complete analysis of the supersymmetric particle spectrum in the Minimal Supergravity (mSUGRA) model where the soft SUSY breaking scalar masses, gaugino masses and trilinear couplings are unified at the GUT scale, so that the electroweak symmetry is broken radiatively. We show that the present constraints on the Higgs boson and superparticle masses from collider searches and precision measurements still allow for large regions of the mSUGRA parameter space where charginos, neutralinos, sleptons and top squarks as well as the heavier Higgs particles, are light enough to be produced…
We study the effects of O(alpha_s) supersymmetric QCD (SQCD) corrections on the total production rate and kinematic distributions of polarized and unpolarized top-pair production in pp and p anti-p collisions. At the Fermilab Tevatron p anti-p collider, top-quark pairs are mainly produced via quark-antiquark annihilation, q anti-q -> t anti-t, while at the CERN LHC pp collider gluon-gluon scattering, g g -> t anti-t, dominates. We compute the complete set of O(alpha_s) SQCD corrections to both production channels and study their dependence on the parameters of the Minimal Supersymmetric Standa…
We re-evaluate prospects for supersymmetry at the proposed International Linear $e^+e^-$ Collider (ILC) in light of the first year of serious data taking at LHC with $\sqrt{s}=7$ TeV and $\sim 5$ fb$^{-1}$ of $pp$ collisions (LHC7). Strong new limits from LHC SUSY searches, along with a hint of a Higgs boson signal around $m_h\sim 125$ GeV, suggest a paradigm shift from previously popular models to ones with new and compelling signatures. We present a variety of new ILC benchmark models, including: natural SUSY, hidden SUSY, NUHM2 with low $m_A$, non-universal gaugino mass (NUGM) model, pMSSM,…
Current ideas for SUPERSYMMETRY searches at the LHC are reviewed. We analyse the discovery prospects for various supersymmetric particles and describe recent ideas on the possibilities of detailed SUSY studies at the LHC. We also combine today's experimental knowledge with some speculations about what might be known by the year 2005 to provide a realistic picture for the LHC start.
In supersymmetric (SUSY) models with the gravitino being the lightest SUSY particle (LSP), the SUSY breaking scale (i.e., the gravitino mass) could be determined by measuring the lifetime of the next-to-lightest SUSY particle (NLSP). However, for an ultralight gravitino of mass of O(1) eV, which is favored cosmologically, the determination of the SUSY breaking scale, or the gravitino mass, is difficult because the NLSP decay length is too short to be measured directly. Recently we proposed a new determination of the gravitino mass by measuring a branching fraction of two decay modes of slepton…
We investigate the production of a heavy charged Higgs boson at hadron colliders within the context of the MSSM. A detailed study is performed for all important production modes and basic background processes for the t\bar{t}b\bar{b} signature. In our analysis we include effects of initial and final state showering, hadronization, and principal detector effects. For the signal production rate we include the leading SUSY quantum effects at high \tanβ>~ mt/mb. Based on the obtained efficiencies for the signal and background we estimate the discovery and exclusion mass limits of the charged Higgs…
For the case of the MSSM and the most general form of the NMSSM (GNMSSM) we determine the reduction in the fine tuning that follows from allowing gaugino masses to be non-degenerate at the unification scale, taking account of the LHC8 bounds on SUSY masses, the Higgs mass bound, gauge coupling unification and the requirement of an acceptable dark matter density. We show that low-fine tuned points fall in the region of gaugino mass ratios predicted by specific unified and string models. For the case of the MSSM the minimum fine tuning is still large, approximately 1:60 allowing for a 3 GeV unce…
We review some recent results and future prospects in the phenomenology of Supersymmmetry. We discuss the searches for superpartner states, the searches for Higgs bosons in the minimal SUSY model, and additional parameter constraints arising in SUSY-GUT models.
Most models of weak scale supersymmetry (SUSY) predict observable rates for production of SUSY matter at the CERN LHC. The SUSY collider events are expected to be rich in jets, isolated (and non-isolated) leptons and missing E_T. After first discussing the merits of mixed axion/axino vs. neutralino cold dark matter in SUSY models, I then survey prospects for detecting SUSY matter at the LHC via leptonic signatures. In the paradigm mSUGRA model, cascade decays of gluinos and squarks should yield high rates for multi-jet plus multi-lepton events, allowing values of m_{\tg}\sim 3 (1.8) TeV to be …
We review the prospects for dark matter (DM) in two classes of supersymmetric (SUSY) models which are characterized by the different mechanism of SUSY breaking, namely the more common supergravity models with very large scale of SUSY breaking and the recent schemes where SUSY is broken at a relatively low scale and gravitinos are likely to be the lightest SUSY particle. We point out that the former scheme is in general associated with the cold dark matter (CDM) scenario, while the latter predicts a warm dark matter (WDM) dominated Universe.
The Zee model is one of promising models of neutrino mass generation mechanism. However, the original Zee model is not on the framework of the ground unification scenario, and moreover, it is recently pointed out that the predicted value of $\sin^2 2θ_{solar}$ must be satisfied the relation $\sin^2 2θ_{solar} > 0.99$. We discuss whether possible GUT versions of the Zee model can be free from the severe constraint $\sin^2 2θ_{solar} >0.99$ or not. We will conclude that the following two models are promising: an R-parity violating SUSY GUT model and an SO(10) model with a 126-plet scalar.
We re-evaluate prospects for supersymmetry at the proposed International Linear e^+e^- Collider (ILC) in light of the first two years of serious data taking at LHC: LHC7 with ~5 fb^{-1} of pp collisions at sqrt{s}=7 TeV and LHC8 with ~20 fb^{-1} at \sqrt{s}=8 TeV. Strong new limits from LHC8 SUSY searches, along with the discovery of a Higgs boson with m_h~125 GeV, suggest a paradigm shift from previously popular models to ones with new and compelling signatures. After a review of the current status of supersymmetry, we present a variety of new ILC benchmark models, including: natural SUSY, ra…
Searches for physics beyond the Standard Model of particle physics are about to enter a new era with the startup of the Large Hadron Collider (LHC) at CERN. Prospects for R-parity conserving supersymmetry discovery and measurements with the ATLAS detector at the LHC are presented. Methods for determining the parameters of the underlying supersymmetry model and the relation to dark matter estimation are discussed.
We revisit the effect of the large stop mixing on the decay and production of the lightest SUSY Higgs at the LHC. We stress that whenever the inclusive 2-photon signature is substantially reduced, associated production, $Wh$ and $t\bar t h$, with the subsequent decay of the Higgs into photons is enhanced and becomes an even more important discovery channel. We also point out that these reductions in the inclusive channel do not occur for the smallest Higgs mass where the significance is known to be lowest. We show that in such scenarios the Higgs can be produced in the decay of the heaviest st…
