μB-driven electroweak symmetry breaking

• Published in: Physics letters. B Vol. 633; no. 4-5; pp. 573 - 582
• Main Authors: Nomura, Yasunori, Poland, David, Tweedie, Brock
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 16.02.2006; Elsevier Science
• Subjects: Exact sciences and technology; Nuclear physics; Physics; The physics of elementary particles and fields; SU theory; Supersymmetric field theory; Superpotential; Higgs bosons; Standard model; Quarks; Sparticles; Singlet; Symmetry breaking
• ISSN: 0370-2693; 1873-2445
• DOI: 10.1016/j.physletb.2005.12.011

We consider a scenario in which the dominant quartic coupling for the Higgs doublets arises from the F-term potential, rather than the conventional SU(2)L×U(1)YD-term potential, in supersymmetric theories. The quartic coupling arises from a superpotential interaction between the two Higgs doublets and a singlet field, but unlike the case in the next-to-minimal supersymmetric standard model the singlet field is not responsible for the generation of the supersymmetric or holomorphic supersymmetry-breaking masses for the Higgs doublets. We find that this naturally leads to a deviation from the conventional picture of top–Yukawa driven electroweak symmetry breaking—electroweak symmetry breaking is triggered by the holomorphic supersymmetry breaking mass for the Higgs doublets (the μB term). This allows a significant improvement for fine-tuning in electroweak symmetry breaking, since the top squarks do not play a major role in raising the Higgs boson mass or in triggering electroweak symmetry breaking and thus can be light. The amount of fine-tuning is given by the squared ratio of the lightest Higgs boson mass to the charged Higgs boson mass, which can be made better than 20%. Solid implications of the scenario include a small value for tanβ, tanβ≲3, and relatively light top squarks.