A Solution to the Supersymmetric Fine-Tuning Problem within the MSSM

Journal Article · Thu Sep 08 04:00:00 EDT 2005 · Physics Letters, (Section) B

DOI:https://doi.org/10.1016/j.physletb.2005.10.003· OSTI ID:878427

Kitano, Ryuichiro; Nomura, Yasunori

Weak scale supersymmetry has a generic problem of fine-tuning in reproducing the correct scale for electroweak symmetry breaking. The problem is particularly severe in the minimal supersymmetric extension of the standard model (MSSM). We present a solution to this problem that does not require an extension of the MSSM at the weak scale. Superparticle masses are generated by a comparable mixture of moduli and anomaly mediated contributions, and the messenger scale of supersymmetry breaking is effectively lowered to the TeV region. Crucial elements for the solution are a large A term for the top squarks and a small B term for the Higgs doublets. Requiring no fine-tuning worse than 20%, we obtain rather sharp predictions on the spectrum. The gaugino masses are almost universal at the weak scale with the mass between 450 and 900 GeV. The squark and slepton masses are also nearly universal at the weak scale with the mass a factor of {radical}2 smaller than that of the gauginos. The only exception is the top squarks whose masses split from the other squark masses by about m{sub t}/{radical}2. The lightest Higgs boson mass is smaller than 120 GeV, while the ratio of the vacuum expectation values for the two Higgs doublets, tan {beta}, is larger than about 5. The lightest superparticle is the neutral Higgsino of the mass below 190 GeV, which can be dark matter of the universe. The mass of the lighter top squark can be smaller than 300 GeV, which may be relevant for Run II at the Tevatron.

• Research Organization: Stanford Linear Accelerator Center (SLAC)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 878427
• Report Number(s): SLAC-PUB-11462; hep-ph/0509039
• Journal Information: Physics Letters, (Section) B, Journal Name: Physics Letters, (Section) B Vol. 631; ISSN PYLBAJ; ISSN 0370-2693
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
EXPECTATION VALUE
FERMILAB TEVATRON
HIGGS BOSONS
MIXTURES
NONLUMINOUS MATTER
Phenomenology-HEP
HEPPH
STANDARD MODEL
SUPERSYMMETRY
SYMMETRY BREAKING
UNIVERSE