Muon g − 2 in an alternative quasi-Yukawa unification with a less fine-tuned seesaw mechanism

• Published in: Physical review. D 2018-03, Vol.97 (5), Article 055007
• Main Authors: Altın, Zafer, Özdal, Özer, Ün, Cem Salih
• Format: Article
• Language: English
• Subjects: Couplings; Higgs bosons; Light; Magnetic moments; Mathematical models; Neutrinos
• ISSN: 2470-0010; 2470-0029
• DOI: 10.1103/PhysRevD.97.055007

We explore the low-scale implications of the Pati-Salam Model including the TeV scale right-handed neutrinos interacting and mixing with the MSSM fields through the inverse seesaw (IS) mechanism in light of the muon anomalous magnetic moment (muon g−2) resolution and highlight the solutions which are compatible with the quasi-Yukawa unification condition (QYU). We find that the presence of the right-handed neutrinos causes heavy smuons as mμ˜≳800  GeV in order to avoid tachyonic staus at the low scale. On the other hand, the sneutrinos can be as light as about 100 GeV, and along with the light charginos of mass ≲400  GeV, they can yield such large contributions to muon g−2 that the discrepancy between the experiment and the theory can be resolved. These solutions also require mχ˜1±≲400  GeV and mχ˜10≲200. We also discuss such light chargino and neutralino along with the light stau (mτ˜≳200  GeV) in the light of current LHC results. Besides, the gluino mass lies in a range ∼[2.5–3.5]  TeV, which is tested in near future experiments. In addition, the model predicts relatively light Higgsinos (μ≲700  GeV); hence, the second chargino mass is also light enough (≲700  GeV) to contribute to muon g−2. Light Higgsinos also yield less fine-tuning at the electroweak scale, and the regions compatible with muon g−2 restrict ΔEW≲100 strictly, and this region also satisfies the QYU condition. In addition, the ratios among the Yukawa couplings should be 1.8≲yt/yb≲2.6, yτ/yb∼1.3 to yield correct fermion masses. Even though the right-handed neutrino Yukawa coupling can be varied freely, the solutions bound its range to 0.8≲yν/yb≲1.7.