We analyze the possible magnitude of the supersymmetric contribution to $g_μ- 2$ in a flipped SU(5) GUT model. Unlike other GUT models which are severely constrained by universality relations, in flipped SU(5) the U(1) gaugino mass and the soft supersymmetry-breaking masses of right-handed sleptons are unrelated to the other gaugino, slepton and squark masses. Consequently, the lightest neutralino and the right-handed smuon may be light enough to mitigate the discrepancy between the experimental measurement of $g_μ- 2$ and the Standard Model calculation, in which case they may be detectable at the LHC and/or a 250 GeV $e^+ e^-$ collider, whereas the other gauginos and sfermions are heavy enough to escape detection at the LHC.
We obtain a phenomenologically acceptable Cabibbo-Kobayashi-Maskawa matrix in a flipped SU(5) model inspired by the compactification of heterotic string $E_8\times E_8'$.
We obtain a phenomenologically acceptable PMNS matrix in a flipped SU(5) model inspired by the compactification of heterotic string $E_8\times E_8'$. To analyze the Jarlskog determinant efficiently, we include the simple Kim-Seo form for the Pontecorbo-Maki-Nakagawa-Sakata matrix. We also noted that $|δ_{\rm PMNS}|\lesssim 64^{\rm o}$ for the normal hierarchy of neutrino masses with the PDG book parametrization.
We consider proton decay and $g_μ- 2$ in flipped SU(5) GUT models. We first study scenarios in which the soft supersymmetry-breaking parameters are constrained to be universal at some high scale $M_{in}$ above the standard GUT scale where the QCD and electroweak SU(2) couplings unify. In this case the proton lifetime is typically $\gtrsim 10^{36}$~yrs, too long to be detected in the foreseeable future, and the supersymmetric contribution to $g_μ- 2$ is too small to contribute significantly to resolving the discrepancy between the experimental measurement and data-driven calculations within the…
We perform a comprehensive study of $SU(5)$, $SO(10)$ and $E(6)$ supersymmetric GUT models where the gaugino masses are generated through the F-term breaking vacuum expectation values of the non-singlet scalar fields. In these models the gauginos are non-universal at the GUT scale unlike in the mSUGRA scenario. We discuss the properties of the LSP which is stable and a viable candidate for cold dark matter. We look for the GUT scale parameter space that leads to the the lightest SM like Higgs mass in the range of 122-127 GeV compatible with the observations at ATLAS and CMS, the relic density …
We study colored Higgsino-mediated proton decay (dimension-five proton decay) in a model based on the flipped $SU(5)$ GUT. In the model, the GUT-breaking ${\bf10}$, ${\bf \overline{10}}$ fields have a GUT-scale mass term and gain VEVs through higher-dimensional operators, which induces an effective mass term between the color triplets in the ${\bf 5}$, ${\bf \bar{5}}$ Higgs fields that is not much smaller than the GUT scale. This model structure gives rise to observable dimension-five proton decay, and at the same time achieves moderate suppression on dimension-five proton decay that softens t…
We analyze nucleon decay modes in a no-scale supersymmetric flipped SU(5) GUT model, and contrast them with the predictions for proton decays via dimension-6 operators in a standard unflipped supersymmetric SU(5) GUT model. We find that these GUT models make very different predictions for the ratios $Γ(p \to π^0 μ^+)/Γ(p \to π^0 e^+)$, $Γ(p \to π^+ \barν)/Γ(p \to π^0 e^+)$, $Γ(p \to K^0 e^+)/Γ(p \to π^0 e^+)$ and $Γ(p \to K^0 μ^+)/Γ(p \to π^0 μ^+)$, and that predictions for the ratios $Γ(p \to π^0 μ^+)/Γ(p \to π^0 e^+)$ and $Γ(p \to π^+ \barν)/Γ(p \to π^0 e^+)$ also differ in variants of the f…
We identify a parameter region where the mass of the lightest CP-even Higgs boson resides in $124.4-126.8$ GeV, and at the same time the degree of tuning a Higgsino-mass parameter (so-called $μ$-parameter) is relaxed above 10% in the minimal supersymmetric standard model (MSSM) with soft supersymmetry breaking terms, by solving the full set of one-loop renormalization group equations numerically. It is found that certain nonuniversal values of gaugino-mass parameters at the so-called grand unification theory (GUT) scale $\sim 10^{16}$ GeV are important ingredients for the MSSM to predict, with…
We propose to generate the flavor structures of the Standard Model plus neutrinos from flipped SU(5) GUT with $A_4$ modular flavor symmetry. Possible way to assign different moduli values for quarks and leptons in modular GUT scheme is discussed. We propose to reduce the multiple modular symmetries to a single modular symmetry in the low energy effective theory with proper boundary conditions. We classify all possible scenarios in this scheme according to the assignments of the modular $A_4$ representations for matter superfields and give the expressions of the quark and lepton mass matrices p…
We study the feasibility of realizing supersymmetric new inflation model, introduced by Senoguz and Shafi in [1], for $SU(5)$ and flipped $SU(5)$ models of grand unified theories (GUTs). This realization requires an additional $U(1)_R \times Z_{n}$ symmetry for its successful implementation. The standard model (SM) gauge singlet scalar components of $24_H$ and $10_H$ GUT Higgs superfields are respectively employed to realize successful inflation in $SU(5)$ and flipped $SU(5)$ models. The predictions of the various inflationary observables lie within the recent Planck bounds on the scalar spect…
We consider two classes of supersymmetric models with nonuniversal gaugino masses at M_GUT in an attempt to resolve the apparent muon g-2 anomaly encountered in the Standard Model. We explore two distinct scenarios, one in which all gaugino masses have the same sign at M_GUT, and a second case with opposite sign gaugino masses. The sfermion masses in both cases are assumed to be universal at M_GUT. We exploit the non universality among gaugino masses to realize large mass splitting between the colored and non-colored sfermions. Thus, the sleptons can have masses in the few hundred GeV range, w…
We investigate neutralino dark matter in supersymmetric flipped SU(5), focusing on candidates with masses of order 30 - 150 GeV and spin independent cross sections that are consistent with the most recent CDMS II results. We assume gravity mediated supersymmetry breaking and restrict the magnitude of the soft supersymmetry breaking mass parameters to 1 TeV or less. With non-universal soft gaugino and Higgs masses, and taking flipped SU(5) into account, we identify allowed regions of the parameter space and highlight some benchmark solutions including Higgs and sparticle spectroscopy.
We study Flipped $SU(5)\times U(1)$ Grand Unified Theories (GUTs) with $Γ_3\simeq A_4$ modular symmetry. We propose two models with different modular weights assignments, where the fermion mass hierarchy can arise from weighton fields. In order to relax the constraint on the Dirac neutrino Yukawa matrix we appeal to mechanisms which allow incomplete GUT representations, allowing a good fit to quark and charged lepton masses and quark mixing for a single modulus field $τ$, with the neutrino masses and lepton mixing well determined by the type I seesaw mechanism, at the expense of some tuning. W…
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 explore the phenomenology of the minimal supersymmetric flipped SU(5) GUT model (CFSU(5)), whose soft supersymmetry-breaking (SSB) mass parameters are constrained to be universal at some input scale, $M_{in}$, above the GUT scale, $M_{GUT}$. We analyze the parameter space of CFSU(5) assuming that the lightest supersymmetric particle (LSP) provides the cosmological cold dark matter, paying careful attention to the matching of parameters at the GUT scale. We first display some specific examples of the evolutions of the SSB parameters that exhibit some generic features. Specifically, we note t…
We investigate the conditions on the Higgs sector that allow supersymmetric SO(10) grand unified theories (GUT) to break spontaneously to the standard electroweak model (SM) at the renormalizable level. If one considers Higgs representations of dimension up to the adjoint, a supersymmetric standard model vacuum requires in most cases the presence of non-renormalizable (NR) operators. The active role of Planck induced NR operators in the breaking of the gauge symmetry introduces a hierarchy in the mass spectrum at the GUT scale that may be an issue for gauge unification and proton decay. We sho…
Viable models with non-universal gaugino mediated supersymmetry breaking
最近，已经提出了额外维超对称大统一模型，其中额外维的紧化导致规范对称性和/或超对称性的崩溃。我们研究了一类特殊的高维模型，它们具有超对称性和SU（5）或SO（10）大统一理论对称性。超对称性破缺发生在一个隐藏的膜上，并通过高吉诺中介传递到可见的膜上。非普适的高更诺质量是在紧化尺度上发展的，这是隐藏膜上受限的规范对称性的结果。在这种情况下，紧化尺度等于或略低于GUT尺度。我们研究的参数空间，这样的模型，其中高吉诺群众相关的Pati-Salam对称性的隐藏膜。我们发现有限的，但重要的区域模型参数空间中产生一个可行的超对称性物质的光谱。我们的结果被推广到更一般的三个独立的高更诺质量的情况下，在这里我们发现，大的参数空间区域打开的大值的U（1）高更诺质量M_1。我们还发现，这些模型的中性伴子的遗迹密度一般低于宇宙学观测的预期，从而为隐藏的扇区状态留下了空间，以弥补大部分的冷暗物质。最后计算了分支分数BF（b-> s γ）和μ子反常磁矩a_μ。
We derive the non-universal gaugino mass ratios in a supergravity (SUGRA) framework where the Higgs superfields belong to the non-singlet representations {\bf 54} and {\bf 770} in a SO(10) Grand Unified Theory (GUT). We evaluate the ratios for the phenomenologically viable intermediate breaking chain $SU(4)_C \times SU(2)_L \times SU(2)_R (G_{422})$. After a full calculation of the gaugino mass ratios, noting some errors in the earlier calculation for {\bf 54}, we obtain, using the renormalisation group equations (RGE), interesting low scale phenomenology of such breaking patterns. Here, we as…
We consider supersymmetric grand unified theory (GUT) with the gaugino mediated supersymmetry breaking and investigate a possibility to discriminate different GUT models in terms of predicted sparticle mass spectra. Taking two example GUT models, the minimal SU(5) and simple SO(10) models, and imposing a variety of theoretical and experimental constraints, we calculate sparticle masses. Fixing parameters of each model so as to result in the same mass of neutralino as the lightest supersymmetric particle (LSP), giving the observed dark matter relic density, we find sizable mass differences in t…
We analyse the prospects for constructing hybrid models of inflation that provide a dynamical realisation of the apparent closeness between the supersymmetric GUT scale and the possible scale of cosmological inflation. In the first place, we consider models based on the flipped SU(5)$\times$U(1) gauge group, which has no magnetic monopoles. In one model, the inflaton is identified with a sneutrino field, and in the other model it is a gauge singlet. In both cases we find regions of the model parameter spaces that are compatible with the experimental magnitudes of the scalar perturbations, $A_s…
We propose a complete cosmological scenario based on a flipped SU(5) $\times$ U(1) GUT model that incorporates Starobinsky-like inflation, taking the subsequent cosmological evolution carefully into account. A single master coupling, $λ_6$, connects the singlet, GUT Higgs and matter fields, controlling 1) inflaton decays and reheating, 2) the gravitino production rate and therefore the non-thermal abundance of the supersymmetric cold dark matter particle, 3) neutrino masses and 4) the baryon asymmetry of the Universe.
We study SO(10), SU(5) and flipped SU(5) GUT models with non-universal soft supersymmetry-breaking scalar masses, exploring how they are constrained by LHC supersymmetry searches and cold dark matter experiments, and how they can be probed and distinguished in future experiments. We find characteristic differences between the various GUT scenarios, particularly in the coannihilation region, which is very sensitive to changes of parameters. For example, the flipped SU(5) GUT predict the possibility of $\tilde{t}_1-χ$ coannihilation, which is absent in the regions of the SO(10) and SU(5) GUT par…
It is shown that substantially enhanced Higgs to diphoton rate induced by light staus with large left-right mixing in MSSM requires at the GUT scale non-universal gaugino masses with bino and/or wino lighter than gluino. The possibility of such enhancement is investigated in MSSM models with arbitrary gaugino masses at the GUT scale with additional restriction of top-bottom-tau Yukawa unification, as predicted by minimal SO(10) GUTs. Many patterns of gaugino masses leading to enhanced Higgs to diphoton rate and the Yukawa unification are identified. Some of these patterns can be accommodated i…
In this paper, we embed the model of flipped GUT sneutrino inflation -in a flipped SU(5) or SO(10) set up- developed by Ellis et al. in a supergravity framework. The GUT symmetry is broken by a waterfall which could happen at early or late stage of the inflationary period. The full field dynamics is thus studied in detail and these two main inflationary configurations are exposed, whose cosmological predictions are both in agreement with recent astrophysical measurements. The model has an interesting feature where the inflaton has natural decay channels to the MSSM particles allowed by the GUT…
We embed a flipped ${\rm SU}(5) \times {\rm U}(1)$ GUT model in a no-scale supergravity framework, and discuss its predictions for cosmic microwave background observables, which are similar to those of the Starobinsky model of inflation. Measurements of the tilt in the spectrum of scalar perturbations in the cosmic microwave background, $n_s$, constrain significantly the model parameters. We also discuss the model's predictions for neutrino masses, and pay particular attention to the behaviours of scalar fields during and after inflation, reheating and the GUT phase transition. We argue in fav…
We consider two distinct classes of Yukawa unified supersymmetric SO(10) models with non-universal and universal soft supersymmetry breaking (SSB) gaugino masses at M_{\rm GUT}. In both cases, we assume that the third family SSB sfermion masses at M_{\rm GUT} are different from the corresponding sfermion masses of the first two families (which are equal). For the SO(10) model with essentially arbitrary (non-universal) gaugino masses at M_{\rm GUT}, it is shown that t-b-τYukawa coupling unification is compatible, among other things, with the 125 GeV Higgs boson mass, the WMAP relic dark matter …
Relations between the gaugino masses have been shown to alleviate the degree of fine-tuning in the MSSM. In this paper we consider specific models of supersymmetry breaking with gravity mediation and demonstrate that within both GUT and string constructions it is possible to generate these relations in a natural way. We have numerically studied the degree of fine-tuning in these models, including one-loop corrections, and have found regions of parameter space that can satisfy all known collider constraints with fine-tunings less than 20%. We discuss some of the phenomenological features of the…
We discuss the SUSY dark matter phenomenology in some simple and predictive models of nonuniversal gaugino masses at the GUT scale. Assuming the gaugino masses to transform as a sum of singlet and a nonsinglet representation of the GUT group SU(5), one can evade the LEP constraints to access the bulk annihilation region of the bino dark matter relic density. Besides, with this assumption one can also have a mixed gaugino-higgsino dark matter, giving the right relic density over large parts of the parameter space. We consider the model predictions for LHC and dark matter experiments in both the…
