Supersymmetric dark matter and Yukawa unification (original) (raw)

Neutralino dark matter and other LHC predictions from quasi Yukawa unification

Nuclear Physics B, 2015

We explore the dark matter and LHC implications of t − b − τ quasi Yukawa unification in the framework of supersymmetric models based on the gauge symmetry G = SU (4) c × SU (2) L × SU (2) R . The deviation from exact Yukawa unification is quantified by a dimensionless parameter C (|C| 0.2), such that the Yukawa couplings at M GUT are related by y t : y b : y τ = |1+C| : |1−C| : |1+3C|. In contrast to earlier studies which focused on universal gaugino masses, we consider non-universal gaugino masses at M GUT that are compatible with the gauge symmetry G. We perform two independent scans of the fundamental parameter space, one of which employs ISAJET, while the other uses SoftSusy interfaced with SuperIso. These scans reveal qualitatively similar allowed regions in the parameter space, and yield a variety of neutralino dark matter scenarios consistent with the observations. These include stau and chargino coannihilation scenarios, the A−resonance scenario, as well as Higgsino dark matter solution which is more readily probed by direct detection searches. The gluino mass is found to be 4.2 TeV, the stop mass is arXiv:1503.04196v1 [hep-ph]

Reconciling Neutralino relic Density with Yukawa Unified Supersymmetric Models

Journal of High Energy Physics, 2004

Supersymmetric grand unified models based on the gauge group SO(10) are especially attractive in light of recent data on neutrino masses. The simplest SO(10) SUSY GUT models predict unification of third generation Yukawa couplings in addition to the usual gauge coupling unification. Recent surveys of Yukawa unified SUSY GUT models predict an inverted scalar mass hierarchy in the spectrum of sparticle masses if the superpotential µ term is positive. In general, such models tend to predict an overabundance of dark matter in the universe. We survey several solutions to the dark matter problem in Yukawa unified supersymmetric models. One solution-lowering the GUT scale mass value of first and second generation scalars-leads toũ R andc R squark masses in the 90−120 GeV regime, which should be accessible to Fermilab Tevatron experiments. We also examine relaxing gaugino mass universality which may solve the relic density problem by having neutralino annihilations via the Z or h resonances, or by having a wino-like LSP.

LHC Run-3, b−taub-\taub−tau Yukawa Unification and Dark Matter Implications in SUSY 4-2-2 model

arXiv (Cornell University), 2022

We revisit the bottom and τ Yukawa coupling unification in supersymmetric 4-2-2 model and present for the first time the sbottom-neutralino co-annihilation scenario consistent with the the bottom and τ Yukawa coupling unification. In addition, we show gluinoneutralino, stop-neutralino, stau-neutralino, chargino-neutralino and A-resonance scenario and show that all such solutions are consistent with existing experimental collider constraints, Planck2018 dark matter relic density bounds as well as direct and indirect bounds on neutralino-nucleons scattering cross sections. We show that in sbottom-neutralino coannihilation scenario, the sbottom mass is about 2 TeV whereas in the case of gluinoneutralino, stop-neutralino, the gluino mass can be between 1 TeV to 3 TeV and stop mass in the range of 1 TeV to 3.5 TeV. Moreover, in the case of co-annihilation scenario, the stau and chargino masses can be as heavy as 3.5 TeV, while the A-resonance solutions are in the range of 0.5 TeV to 3.5 TeV. We anticipate that some part of the parameter space will be accessible in the supersymmetry searches at LHC Run-3 and beyond.

Dark Matter and Higgs Mass in the CMSSM with Yukawa Quasi-Unification

We present an updated analysis of the constrained minimal supersymmetric standard model with mu>0 supplemented by an `asymptotic' Yukawa coupling quasi-unification condition, which allows an acceptable b-quark mass. Imposing constraints from the cold dark matter abundance in the universe, B physics, the muon anomalous magnetic moment, and the mass m_h of the lightest neutral CP-even Higgs boson, we find that the lightest neutralino cannot act as a cold dark matter candidate. This is mainly because the upper bound on the lightest neutralino relic abundance from cold dark matter considerations, despite the fact that this abundance is drastically reduced by neutralino-stau coannihilations, is incompatible with the recent data on the branching ratio of B_s --> mu^+ mu^-. Allowing for a different particle, such as the axino or the gravitino, to be the lightest supersymmetric particle and, thus, constitute the cold dark matter in the universe, we find that the predicted m_h's in our model favor the range (119-126) GeV.

Dark Matter and Yukawa Unification with Massive Neutrinos

AIP Conference Proceedings, 2009

We revisit the WMAP dark matter constraints on Yukawa Unification in the presence of massive neutrinos. The large neutrino mixing indicated by the data modifies the predictions for the bottom quark mass, and enables Yukawa also for large tan β, and for positive µ that were previously disfavoured. As a result, the allowed parameter space for neutralino dark matter also increases, particularly for areas with resonant enhancement of the neutralino relic density.

Third family quasi-Yukawa unification: Higgsino dark matter, NLSP gluino and all that

arXiv (Cornell University), 2023

We explore the implications of third family (t − b − τ) quasi-Yukawa unification (QYU) for collider and dark matter (DM) searches within the framework of a supersymmetric SU (4) c × SU (2) L × SU (2) R model. The deviation from exact Yukawa unification is quantified through the relation y t : y b : y τ = |1 + C| : |1 − C| : |1 + 3C|, with C being a real parameter (|C| ≤ 0.2). We allow for the breaking of left-right symmetry both by the soft scalar and gaugino mass parameters and obtain a variety of viable solutions that predict the sparticle mass spectrum including LSP DM (whose stability is guaranteed by a Z 2 gauge symmetry). We highlight solutions that include an NLSP gluino with mass ∼ 1.3-2.5 TeV, which should be accessible at LHC Run 3. There also exist NSLP stop solutions with masses heavier than about 1.8 TeV, which are consistent with the LSP neutralino dark matter relic density through stop-neutralino coannihilation. We identify A-resonance solutions with DM mass ∼ 0.8-2 TeV, as well as bino-chargino, bino-slepton and bino-stau co-annihilation scenarios. Finally, we also identify Wino-like (∼ 99%) and Higgsino-like (∼ 99%) solutions whose masses are heavier than about 1.5 TeV and 1 TeV, respectively. These solutions are compatible with the desired dark matter relic density and testable in ongoing and future direct detection experiments.

New constraints on neutralino dark matter in the supersymmetric standard model

Physical Review D, 1993

We investigate the prospects for neutralino dark matter within the Supersymmetric Standard Model (SSM) including the constraints from universal soft supersymmetry breaking and radiative breaking of the electroweak symmetry. The latter is enforced by using the one-loop Higgs effective potential which automatically gives the one-loop corrected Higgs boson masses. We perform an exhaustive search of the allowed five-dimensional parameter space and find that the neutralino relic abundance Omegachih20\Omega_\chi h^2_0Omegachih20 depends most strongly on the ratio xi0equivm0/m1/2\xi_0\equiv m_0/m_{1/2}xi0equivm0/m1/2. For xi0gg1\xi_0\gg1xi0gg1 the relic abundance is almost always much too large, whereas for xi0ll1\xi_0\ll1xi0ll1 the opposite occurs. For xi0sim1\xi_0\sim1xi0sim1 there are wide ranges of the remaining parameters for which Omegachisim1\Omega_\chi\sim1Omegachisim1. We also determine that mtildeqgsim250GeVm_{\tilde q}\gsim250\GeVmtildeqgsim250GeV and mtildelgsim100GeVm_{\tilde l}\gsim100\GeVmtildelgsim100GeV are necessary in order to possibly achieve Omegachisim1\Omega_\chi\sim1Omegachisim1. These lower bounds are much weaker than the corresponding ones derived previously when radiative breaking was {\it not} enforced.

Supersymmetric cold dark matter with Yukawa unification

Physical Review D, 2000

The cosmological relic density of the lightest supersymmetric particle of the minimal supersymmetric standard model is calculated under the assumption of gauge and Yukawa coupling unification. We employ radiative electroweak breaking with universal boundary conditions from gravity-mediated supersymmetry breaking. Coannihilation of the lightest supersymmetric particle, which turns out to be an almost pure bino, with the next-to-lightest supersymmetric particle (the lightest stau) is crucial for reducing its relic density to an acceptable level. Agreement with the mixed or the pure cold (in the presence of a nonzero cosmological constant) dark matter scenarios for large scale structure formation in the universe requires that the lightest stau mass is about 1.5 − 7.5% larger than the bino mass, which can be as low as 223 GeV. The smallest allowed value of the lightest stau mass turns out to be about 233 GeV.

Dark matter allowed scenarios for Yukawa-unified SO(10) SUSY GUTs

Journal of High Energy Physics, 2008

Simple supersymmetric grand unified models based on the gauge group SO(10) require-in addition to gauge and matter unification-the unification of t-b-τ Yukawa couplings. Owing to sparticle contributions to fermion self-energy diagrams, the Yukawa unification however only occurs for very special values of the soft SUSY breaking parameters. We perform a search using a Markov Chain Monte Carlo (MCMC) technique to investigate model parameters and sparticle mass spectra which occur in Yukawa-unified SUSY models, where we also require the relic density of neutralino dark matter to saturate the WMAPmeasured abundance. For Yukawa unified models with µ > 0, the spectrum is characterizd by three mass scales: first and second generation scalars in the multi-TeV range, third generation scalars in the TeV range, and gauginos in the ∼ 100 GeV range. Most solutions give far too high a relic abundance of neutralino dark matter. The dark matter discrepancy can be rectified by i). allowing for neutralino decay to axino plus photon, ii). imposing gaugino mass non-universality or iii). imposing generational non-universality. In addition, the MCMC approach finds a compromise solution where scalar masses are not too heavy, and where neutralino annihilation occurs via the light Higgs h resonance. By imposing weak scale Higgs soft term boundary conditions, we are also able to generate low µ, m A solutions with neutralino annihilation via a light A resonance, though these solutions seem to be excluded by CDF/D0 measurements of the B s → µ + µ − branching fraction. Based on the dual requirements of Yukawa coupling unification and dark matter relic density, we predict new physics signals at the LHC from pair production of 350-450 GeV gluinos. The events are characterized by very high b-jet multiplicity and a dilepton mass edge around mχ0 2 − mχ0 1 ∼ 50-75 GeV.