Brief comments on signals at 7 TeV in the Higgs funnel region of mSUGRA, models with non universal scalar and gaugino masses have been added. Accepted for publication in PRD
We have analysed the early LHC signatures of the minimal supergravity (mSUGRA) model. Our emphasis is on the 7 - $TeV$ run corresponding to an integrated luminosity of $\sim 1.0 ~fb^{-1}$ although we have also discussed briefly the prospects at LHC-10 $TeV$. We focus on the parameter space yielding relatively light squark and gluinos consistent with the darkmatter relic density data and the LEP bounds on the lightest Higgs scalar mass. This parameter space is only allowed for non-vanishing trilinear soft breaking term $A_0$. A significant region of the parameter space with large to moderate negative values of $A_0$ consistent with the stability of the scalar potential and relic density production via neutralino annihilation and/or neutralino - stau coannihilation yields observable signal via the jets + missing transverse energy channel. The one lepton + jets + missing energy signal is also viable over a smaller but non-trivial parameter space. The ratio of the size of the two signals - free from theoretical uncertainties - may distinguish between different relic density generating mechanisms. With efficient $τ$-tagging facilities at 7 $TeV$ the discriminating power may increase significantly. We also comment on other dark matter relic density allowed mSUGRA scenarios and variants there of in the context of LHC-7 $TeV$.
ATLAS and CMS collaborations have searched for the supersymmetry (SUSY) in different channels with 7 TeV center-of-mass energy and their search strategies are optimized for the SUSY scenarios with fairly large mass splittings among the sparticles. In absence of any significant deviation of the data from the Standard Model (SM) prediction, stringent bounds are imposed on the squarks and gluino masses in the context of different SUSY scenarios. Since the exact SUSY breaking mechanism is not known, some part of the SUSY spectrum may be degenerate. In this paper, we consider two particular cases o…
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 have examined the capability of the LHC, running at both 7 and 8 TeV, to explore the 19(20)-dimensional parameter space of the pMSSM with neutralino(gravitino) LSPs and soft masses up to 4 TeV employing the ATLAS SUSY analysis suite. Here we present some preliminary results for the gravitino model set, following the ATLAS analyses whose data were publically available as of mid-September 2012. We find that the impact of the reduced MET, resulting from models with gravitino LSPs on sparticle searches is more than off-set by the detectability of the many possible long-lived NLSPs.
Grand Unified Theories (GUTs) are attractive candidates for more fundamental elementary particle theories. They can not only unify the Standard Model (SM) interactions but also different types of SM fermions, in particular quarks and leptons, in joint representations of the GUT gauge group. We discuss how comparing predictive supersymmetric GUT models with the experimental results for quark and charged lepton masses leads to constraints on the SUSY spectrum. We show an example from a recent analysis where the resulting superpartner masses where found just beyond the reach of LHC run 1, but ful…
This document emerged from work that started in January 2012 as a joint effort by the ATLAS, CMS and LPCC supersymmetry (SUSY) working groups to compile state-of-the-art cross section predictions for SUSY particle production at the LHC. We present cross sections for various SUSY processes in pp collisions at $\sqrt{s} =7$ TeV, including an estimate of the theoretical uncertainty due to scale variation and the parton distribution functions. Further results for higher LHC centre-of-mass energies will be collected at https://twiki.cern.ch/twiki/bin/view/LHCPhysics/SUSYCrossSections. For squark an…
We probe the high scale SUSY at 10-50 TeV in the CP violations of K, B0 and Bs mesons. In order to estimate the contribution of the squark flavor mixing to these CP violations, we discuss the squark mass spectrum, which is consistent with the recent Higgs discovery. Taking the universal soft parameters at the SUSY breaking scale, we obtain the squark mass spectrum at 10 TeV and 50 TeV, where the SM emerges. Then, the 6times6 mixing matrix between down-squarks and down-quarks is discussed by input of the experimental data of K, B0 and Bs mesons.It is found that epsilon_K is most sensitive to th…
Direct searches and the hints for the Higgs at ~125 GeV put increasing pressure on simple models of SUSY breaking, in particular (but not exclusively) on those that automatically solve the flavour problem, such as gauge mediation. SUSY-breaking parameters are pushed to higher and higher values, increasing the fine-tuning required to achieve electroweak symmetry breaking at the observed scale. In this note we consider the situation for models which do not attempt to solve the flavour problem. To treat them on equal footing, we consider the combined fine-tuning arising from electroweak symmetry …
We investigate the possibility of U(1)' mediation, leading to an effective SUSY where the first two family sfermions are above 100 TeV but the third family sfermions and the Higgs doublets are in the TeV region(or the light stop case). The U(1)' gaugino, Zprimino, needs not to be at a TeV scale, but needs to be somewhat lighter than the messenger scale. We consider two cases, one the mediation is only through U(1)' and the other through U(1)' and the electroweak hypercharge U(1)_Y. In the SUSY field theory framework, we calculate the superpartner mass spectra for these two cases. We also point…
After completion of the LHC8 run in 2012, the plan is to upgrade the LHC for operation close to its design energy sqrt{s}=14 TeV, with a goal of collecting hundreds of fb^{-1} of integrated luminosity. The time is propitious to begin thinking of what is gained by even further LHC upgrades. In this report, we compute an LHC14 reach for SUSY in the mSUGRA/CMSSM model with an anticipated high luminosity upgrade. We find that LHC14 with 300 (3000) fb^{-1} has a reach for SUSY via gluino/squark searches of m(gluino)\sim3.2 TeV (3.6 TeV) for m(squark)\sim m)gluino), and a reach of m(gluino)\sim1.8 T…
In this paper we examine gauge coupling unification of the the non-SUSY SO(10) grand unified theory proposed by Babu and Mohapatra at the two loop level. This theory breaks down to the standard model in a single step and has the distinguishing feature of TeV non-standard model scalars. This leads to a plethora of interesting new physics at the TeV scale and the discovery of new particles at the LHC. This model gives rise to testable proton decay, neutron-antineutron oscillations, provides a mechanism for baryogenesis, and contains potential dark matter candidates. In this paper, we compute the…
It has been argued that requiring low electroweak fine-tuning (EWFT) along with a (partial) decoupling solution to the SUSY flavor and CP problems leads to a sparticle mass spectra characterized by light Higgsinos at 100-300 GeV, sub-TeV third generation scalars, gluinos at a few TeV and multi-TeV first/second generation scalars (natural SUSY). We show that by starting with multi-TeV first/second and third generation scalars and trilinear soft breaking terms, the natural SUSY spectrum can be generated radiatively via renormalization group running effects. Using the complete 1-loop effective po…
The muon anomalous magnetic moment $a_μ$ is investigated in the MSSM for $\tanβ\to\infty$. This is an attractive example of radiative muon mass generation with completely different qualitative parameter dependence compared to the MSSM with the usual, finite $\tanβ$. The observed, positive difference between the experimental and Standard Model value can only be explained if there are mass splittings, such that bino contributions dominate over wino ones. The two most promising cases are characterized either by large Higgsino mass $μ$ or by large left-handed smuon mass $m_L$. The required mass sp…
In this paper we analyze Yukawa unification in a three family SO(10) SUSY GUT. We perform a global $χ^2$ analysis and show that SUSY effects do not decouple even though the universal scalar mass parameter at the GUT scale, $m_{16}$, is found to lie between 15 and 30 TeV with the best fit given for $m_{16} \approx 25$ TeV. Note, SUSY effects don't decouple since stops and bottoms have mass of order 5 TeV, due to RG running from $M_{GUT}$. The model has many testable predictions. Gauginos are the lightest sparticles and the light Higgs boson is very much Standard Model-like. The model is consist…
Supersymmetric models with radiatively-driven naturalness (RNS) enjoy low electroweak fine-tuning whilst respecting LHC search limits on gluinos and top squarks and allowing for $m_h\simeq 125$ GeV. While the heavier Higgs bosons $H,\ A$ may have TeV-scale masses, the SUSY conserving $μ$ parameter must lie in the few hundred GeV range. Thus, in natural SUSY models there should occur large heavy Higgs boson branching fractions to electroweakinos, with Higgs boson decays to higgsino plus gaugino dominating when they are kinematically accessible. These SUSY decays can open up new avenues for disc…
We have discussed the stop mass and possible signal processes within a class of SUSY GUTs with non-universal gaugino masses. This class of models predicts the stop mass in a wide range from about 400 GeV to 8 TeV, and the DM constraints bound it as $m_{\tilde{t}_{1}}\gtrsim 500$ GeV. Being the lightest supersymmetric particle the neutralino always takes part in possible signal processes, and its mass is realized as heavy as about 2.3 TeV in the fundamental parameter space. Similarly, the lightest chargino mass can be realized beyond 3 TeV, while the DM constraints bound its mass at about 2.7 T…
We estimate the sensitivity of the 14 TeV LHC run to an R-parity violating supersymmetric model, via the same-sign dilepton (SSDL) signature. We consider the simplified model with light gluinos and stops, motivated by naturalness. We find that gluinos up to 1.4 TeV can be discovered with an integrated luminosity of 300 fb-1. If a high-luminosity option is implemented and a 3000 fb-1 dataset becomes available, the gluino mass reach can be increased to 1.6-1.75 TeV.
The string axion may provide the most attractive solution to the strong CP problem in QCD. However, the axion energy density easily exceeds the dark matter density in the present universe due to a large decay constant around $10^{16}$ GeV, unless the initial value of the axion field is fine-tuned. We show that this problem is alleviated if and only if the SUSY particle mass scale is 10-100 TeV, since the decay of the saxion can produce a large enough amount of entropy after the QCD phase transition, not disturbing the BBN prediction. The saxion decay also produces a large number of the lightes…
In this paper we take B-L supersymmetric standard model (B-LSSM) and TeV scale left-right symmetric model (LRSM) as two representations of the two kinds of new physics models to study the nuclear neutrinoless double beta decays ($0\nu2β$) so as to see the senses onto these two kinds of models when the decays are taken into account additionally. Within the parameter spaces allowed by all the exist experimental data, the decay half-life of the nucleus $^{76}$Ge and $^{136}$Xe, $T^{0ν}_{1/2}$($^{76}$Ge, $^{136}$Xe), is precisely calculated and the results are presented properly. Based on the nume…
In a recent paper, we proposed a new class of supersymmetric SO(10) models for neutrino masses where the TeV scale electroweak symmetry is SU(2)_L\times SU(2)_R\times U(1)_{B-L} making the associated gauge bosons W_R and Z' accessible at the Large Hadron Collider. We showed that there exists a domain of Yukawa coupling parameters and symmetry breaking patterns which give an excellent fit to all fermion masses including neutrinos. In this sequel, we discuss an alternative Yukawa pattern which also gives good fermion mass fit and then study the predictions of both models for proton lifetime. Con…
Among three typical energy scales, a neutrino mass scale ($m_ν\sim$ 0.1 eV), a GUT scale ($M_{GUT}\sim 10^{16}$ GeV), and a TeV-scale ($M_{NP}\sim$ 1 TeV), there is a fascinating relation of $M_{NP}\simeq \sqrt{m_ν\cdot M_{GUT}}$.The TeV-scale, $M_{NP}$, is a new physics scale beyond the standard model which is regarded as "supersymmetry" (SUSY) in this letter. We investigate phenomenology of SUSY SU(5) GUT with neutrinophilic Higgs, which realizes the above relation dynamically as well as the suitable magnitude of Dirac mass, $m_ν$, through a tiny vacuum expectation value of neutrinophilic Hi…
We have systematically investigated the production of a Higgs boson with a mass of about $125$ GeV in the decays of supersymmetric particles within the phenomenological MSSM (pMSSM). We find regions of parameter space that are consistent with all world data and that predict a sizeable rate of anomalous Higgs, di-Higgs and even tri-Higgs events at the 14 TeV LHC. All relevant SUSY production processes are investigated. We find that Higgs bosons can be produced in a large variety of SUSY processes, resulting in a large range of different detector signatures containing missing transverse momentum…
We revisit four generations within the context of supersymmetry. We compute the perturbativity limits for the fourth generation Yukawa couplings and show that if the masses of the fourth generation lie within reasonable limits of their present experimental lower bounds, it is possible to have perturbativity only up to scales around 1000 TeV. Such low scales are ideally suited to incorporate gauge mediated supersymmetry breaking, where the mediation scale can be as low as 10-20 TeV. The minimal messenger model, however, is highly constrained. While lack of electroweak symmetry breaking rules ou…
We briefly review the super-natural supersymmetry (SUSY), which provides a most promising solution to the SUSY electroweak fine-tuning problem. In particular, we address its subtle issues as well. Unlike the Minimal Supersymmetric Standard model (MSSM), the Next to MSSM (NMSSM) can be scale invariant and has no mass parameter in its Lagrangian before SUSY and gauge symmetry breakings. Therefore, the NMSSM is a perfect framework for super-natural SUSY. To give the SUSY breaking soft mass to the singlet, we consider the moduli and dilaton dominant SUSY breaking scenarios in M-theory on $S^1/Z_2$…
Results are presented for a variety of SUSY Simplified Models at the 14 TeV LHC as well as a 33 and 100 TeV proton collider. Our focus is on models whose signals are driven by colored production. We present projections of the upper limit and discovery reach in the gluino-neutralino (for both light and heavy flavor decays), squark-neutralino, and gluino-squark Simplified Model planes. Depending on the model a jets + MET, mono-jet, or same-sign di-lepton search is applied. The impact of pileup is explored. This study utilizes the Snowmass backgrounds and combined detector. Assuming 3000 fb^{-1} …
Many extensions of the Standard Model include a new $U(1)$ gauge group that is broken spontaneously at a scale much above TeV. If a $U(1)$-breaking phase transition occurs at nucleation temperature of $O(100)$-$O(1000)$~TeV, it can generate stochastic gravitational waves in $O(10)$-$O(100)$ Hz range if $β_{\rm n}/H_{\rm n}=1000$, which can be detected by ground-based detectors. Meanwhile, supersymmetry (SUSY) may play a crucial role in the dynamics of such high-scale $U(1)$ gauge symmetry breaking, because SUSY breaking scale is expected to be at TeV to solve the hierarchy problem. In this pap…
We examine the discovery reach of LHC14 for supersymmetry for integrated luminosity ranging from 0.3 to 3 ab^{-1}. In models with gaugino mass unification and M_1,\ M_2<< |μ| (as for mSUGRA/CMSSM), we find a reach of LHC14 with 3 ab^{-1} for gluino pair production extends to m_{\tg} 2.3 TeV while the reach via \tw_1\tz_2 \to W h +ETmiss extends to m_{\tg}\sim 2.6 TeV.
We consider the current experimental constraints on the parameter space of the MSSM and NMSSM. Then in the allowed parameter space we examine the Higgs pair production at the 14 TeV LHC via $b\bar{b}\to hh$ ($h$ is the 125 GeV SM-like Higg boson) with one-loop SUSY QCD correction and compare it with the production via $gg\to hh$. We obtain the following observations: (i) For the MSSM the production rate of $b\bar{b} \to hh$ can reach 50 fb and thus can be competitive with $gg \to hh$, while for the NMSSM $b\bar{b} \to hh$ has a much smaller rate than $gg \to hh$ due to the suppression of the $…
We discuss the sensitivity of the high-scale SUSY at $10$-$1000$ TeV in $B^0$, $B_s$, $K^0$ and $D$ meson systems together with the neutron EDM and the mercury EDM. In order to estimate the contribution of the squark flavor mixing to these FCNCs,we calculate the squark mass spectrum, which is consistent with the recent Higgs discovery. The SUSY contribution in $ε_K$ could be large, around 40% in the region of the SUSY scale $10$-$100$ TeV. The neutron EDM and the mercury EDM are also sensitive to the SUSY contribution induced by the gluino-squark interaction. The predicted EDMs are roughly pro…
In this work we consider the HL-LHC discovery potential in the 3 inverse ab data set for gluinos in the gluino-weakino associated production channel. We propose a search in the jets plus missing energy channel which exploits kinematic edge features in the reconstructed transverse mass of the gluino. We find that for squark masses in the 2 TeV range we have 5 sigma discovery potential for gluino masses in the range of 2.4 to 3 TeV, competitive with the projections for discovery potential in the gluino pair production channel.
We celebrate the recent Higgs discovery announcement with our experimental colleagues at the LHC and look forward to the implications that this success will bring to bear upon the continuing search for supersymmetry (SUSY). The model framework named No-Scale F-SU(5) possesses the rather unique capacity to provide a light CP-even Higgs boson mass in the favored 124-126 GeV window while simultaneously retaining a testably light SUSY spectrum that is consistent with emerging low-statistics excesses beyond the Standard Model expectation in the ATLAS and CMS multijet data. In this letter we review …
We explore naturalness constraints on the masses of the heavy Higgs bosons H^0, H^+/-, and A^0 in supersymmetric theories. We show that, in any extension of MSSM which accommodates the 125 GeV Higgs at the tree level, one can derive an upper bound on the SUSY Higgs masses from naturalness considerations. As is well-known for the MSSM, these bounds become weak at large tan beta. However, we show that measurements of b to s gamma together with naturalness arguments lead to an upper bound on tan beta, strengthening the naturalness case for heavy Higgs states near the TeV scale. The precise bound …
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…
We examine the ATLAS and CMS 7 & 8 TeV multijet supersymmetry (SUSY) searches requiring the incidence of a single lepton in the framework of the supersymmetric grand unified model No-Scale Flipped SU(5) with extra vector-like flippon multiplets derived from F-Theory, or F-SU(5) for short. Investigated are five multijet+lepton SUSY searches: 4.7/fb ATLAS 7 TeV gluino and light stop searches, as well as 13/fb ATLAS and 9.7/fb CMS 8 TeV light stop searches. Most significantly, all five leptonic SUSY searches represent statistically independent data samples. Findings show that all five orthogonal …
We use the Higgs coupling and the muon anomalous magnetic moment measurements to constrain the parameter space of the natural supersymmetry (SUSY) in the Generalized Minimal Supergravity (GmSUGRA) model. We scan the parameter space of the GmSUGRA model with small electroweak fine-tuning measure ($Δ_{\rm EW} \leq 100$). The parameter space after applying various sparticle mass bounds, Higgs mass bounds, B-physics bounds, the muon magnetic moment constraint, and the Higgs coupling constraint from measurements at HL-LHC, ILC, and CEPC, is shown in the planes of various interesting model parameter…
Inspired by the recent LHC Higgs data and null search results of supersymmetry (SUSY), we scan the parameter space of the Minimal Supersymmetric Standard Model (MSSM) with relatively heavy sparticles (1-3 TeV). Then in the parameter space allowed by current collider experiments and dark matter detections, we calculate the complete one-loop SUSY QCD corrections to $pp\to b\bar{b}h$ at the LHC with $\sqrt{s}=14$ TeV and obtain the following observations: (i) For the large values of $\tanβ$ and low values of $m_{A}$, the SUSY QCD effects can be quite large, which, however, have been excluded by t…
Motivated by the recent discovery of the Higgs boson at m_h = 126 GeV and also by the non-observation of superparticles at the LHC, high-scale SUSY, where the superparticles are as heavy as O(10) TeV, has been recently proposed. We study lepton-flavor violations (LFVs) in the high-scale SUSY with right-handed neutrinos. Even if the slepton masses are of O(10) TeV, the renormalization group (RG) effects on the slepton mass-squared matrix may induce large enough LFVs which are within the reach of future LFV experiments. We also discuss the implication of the right-handed neutrinos on the electro…
We suggest simple ways of implementing Peccei-Quinn (PQ) symmetry to solve the strong CP problem in renormalizable SUSY $SO(10)$ models with a minimal Yukawa sector. Realistic fermion mass generation requires that a second pair of Higgs doublets survive down to the PQ scale. We show how unification of gauge couplings can be achieved in this context. Higgsino mediated proton decay rate is strongly suppressed by a factor of $(M_{\rm PQ}/M_{\rm GUT})^2$, which enables all SUSY particles to have masses of order TeV. With TeV scale SUSY spectrum, $p \rightarrow \overlineν K^+$ decay rate is expecte…
The data obtained by the LHC collaborations clearly show that supersymmetric models are not realized in nature in a vanilla form and that in particular strongly interacting supersymmetric particles are most likely heavier than expected. An exception are the partners of the third generation quarks, which also play a dominant role in the breaking of the electroweak symmetry. We consider here an extended class of so-called `natural supersymmetric models' where we allow for a sneutrino as the lightest supersymmetric particle as it appears for example in left-right symmetric models and/or models wh…
