Light staus and enhanced Higgs diphoton rate with non-universal gaugino masses and SO(10) Yukawa unification

Abstract

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 in a well-motivated scenarios such as mirage mediation or SUSY breaking F -terms being a nonsinglet of SO(10). Phenomenological implications of a scenario with non-universal gaugino masses generated by a mixture of the singlet F -term and the F -term in a 24-dimensional representation of SU(5) ⊂ SO(10) are studied in detail. Possible non-universalities of other soft terms generated by such F-terms are discussed. The enhancement of Higgs to diphoton rate up to 30% can be obtained in agreement with all phenomenological constraints, including vacuum metastability bounds. The lightest sbottom and pseudoscalar Higgs are within easy reach of the 14 TeV LHC. The LSP can be either bino-like or wino-like. The thermal relic abundance in the former case may be in agreement with the cosmological data thanks to efficient stau coannihilation.

Split sfermion families, Yukawa unification and muon g − 2

“…On the other hand, as we mentioned above, t-b-τ YU requires [9][10][11][12][13][14][15][16][17][18][19] the sleptons to be around a TeV or above, if universality among sfermion masses is assumed at M GUT . Our analysis in the following sections show that the non-universal gaugino case with split family sfermions can resolve the g − 2 discrepancy and also realize t-b-τ Yukawa unification, while staying consistent with all current experimental data.…”

“…For this case, 10% or better t-b-τ Yukawa unification consistent with all constraints (including the Higgs boson mass) requires m 0 1 TeV and m 1/2 1 TeV [18,19]. The colored sparticle spectrum does not change much [12][13][14][15][16][17] if we consider different mass relations among the gauginos at M GUT , but the sleptons can be light. Again it leads to heavy first and second generation squarks which are beyond the reach of LHC 14 [36].…”

“…In this scenario the desired supersymmetric threshold corrections to t-b-τ Yukawa couplings can be realized with Mg mb [12][13][14][15][16][17]. For a particular choice of SSB gaugino masses (M 1 : M 2 : M 3 = 1 : 3 : −2) at M GUT , which can be derived in the framework of SO(10) GUT, it was shown [18,19] that the CP-even SM-like Higgs boson mass m h ≈ 125 GeV can be predicted from t-b-τ YU.…”

“…On the other hand, imposing t-b-τ Yukawa coupling unification condition at M GUT [6][7][8] can place significant constraints on the supersymmetric spectrum in order to fit the top, bottom and tau masses. These constraints are quite severe [9][10][11][12][13][14][15][16][17][18][19], especially after the discovery of a SM like Higgs boson with mass, m h 125 − 126 GeV [20,21].…”

Top quark and Higgs boson masses in supersymmetric models

“…An upper bound for the top quark mass is obtained by imposing perturbativity on the top Yukawa coupling up to M GUT . It is possible [19][20][21][22][23][24][25][26][27][28] to relax the universality of SSB Higgs mass 2 terms along with the non-universality of SSB gaugino mass terms, but we restrict ourselves here to the above two classes.…”