16966315
Impact of squark pair decay modes on search for supersymmetric neutral Higgs bosons
Abstract We present a detailed study of the decays of the neutral Higgs bosons H 0 and A 0 within the Minimal Supersymmetric Standard Model. We find that the supersymmetric modes tt and bb can dominate the H 0 and A 0 decays in a wide range of the model parameters due to large Yukawa couplings and mixings of t and b . Compared to the conventional modes t t and b b , these modes have very distinctive signatures. This could have a decisive impact on the neutral Higgs boson searches at future colliders.
17333378
SUSY - QCD corrections to top and bottom squark decays into Higgs bosons
We calculate the $\mathcal{O}({\ensuremath{\alpha}}_{s})$ SUSY-QCD corrections to the widths of top and bottom squark decays into Higgs bosons within the minimal supersymmetric standard model. We give the complete analytical formulas, paying particular attention to the on-shell renormalization of the soft SUSY-breaking parameters. We also perform a detailed numerical analysis of both top and bottom squark decays into all Higgs bosons ${h}^{0},$ ${H}^{0},$ ${A}^{0},$ and ${H}^{\ifmmode\pm\else\textpm\fi{}}.$ We find that the SUSY-QCD corrections are significant, mostly negative, and of the order of a few ten percent.
11356307
Two-loop renormalization of gaugino masses in general supersymmetric gauge models.
We calculate the two-loop renormalization group equations for the running gaugino masses in general supersymmetry (SUSY) gauge models, improving our previous result. We also study its consequences on the unification of the gaugino masses in the SUSY SU(5) model. The two-loop correction to the one-loop relation [ital m][sub [ital i]]([mu])[proportional to][alpha][sub [ital i]]([mu]) is found to be of the order of a few percent.
2040672
Radiative corrections to a supersymmetric relation: A new approach
Recently it has been realized that the production and decay processes of charginos, neutralinos, and sleptons receive corrections which grow like logm{sub {tilde q}} for large m{sub {tilde q}}. In this paper we calculate the chargino pair production cross section at e{sup +}e{sup {minus}} colliders with quark-squark loop corrections. We introduce a novel formulation, where the one-loop amplitude is reorganized into two parts. One part is expressed in terms of the {open_quotes}effective{close_quotes} chargino coupling {bar g}{sub e{tilde {nu}}{tilde W}} and mixing matrices U{sup P},V{sup P}, and includes all O(logm{sub {tilde q}}) corrections, while the other decouples for large m{sub {tilde q}}. The form of the one-loop cross section then becomes physically transparent. Our formulation can be easily extended to other loops and processes. Numerically, we find significant corrections due to the effective t-channel coupling {bar g}{sub e{tilde {nu}}{tilde W}}, for gaugino-like charginos. In the mixed region, where the chargino has large gaugino and Higgsino components, the corrections due to (U{sup P},V{sup P}) are also significant. Our numerical results disagree with a previous calculation. We reexamine previous studies of the determination of {bar g}{sub e{tilde {nu}}{tilde W}} through the measurement of the chargino production cross section. We point out that amore » previous study, which claimed that the measurement suffers large systematic errors, was performed at a {open_quotes}pessimistic{close_quotes} point in MSSM parameter space. We provide reasons why the systematic errors are not a limiting factor for generic parameter choices. {copyright} {ital 1998} {ital The American Physical Society}« less
16212962
Motivations for and implications of nonuniversal GUT scale boundary conditions for soft SUSY breaking parameters
We outline several well-motivated models in which GUT boundary conditions for SUSY breaking are non-universal. The diverse phenomenological implications of the non-universality for SUSY discovery at LEP2, the Tevatron, the LHC and the NLC are sketched.
16486262
SUSY--QCD Corrections to Higgs Particle Decays into Quarks and Squarks
We study the decays of the Higgs bosons $H^{\pm}$, $H^0$, and $A^0$ within the Minimal Supersymmetric Standard Model. For decays into quarks and squarks we include the supersymmetric QCD radiative corrections. We find that the corrections are significant and can go up to 50%. The supersymmetric decay modes $H^+ \to \tilde t \bar{\tilde b}$ and $H^0 (A^0) \to \tilde t \bar{\tilde t}$ can be dominant in a wide range of the model parameters due to the large Yukawa couplings and mixings of $\tilde t$ and $\tilde b$.
119238697
Natural realization of a large extra dimension in 5D supersymmetric theory
An exponentially large extra dimension can be naturally realized by the Casimir energy and the gaugino condensation in 5D supersymmetric theory. The model does not require any hierarchies among the 5D parameters. The key ingredient is an additional modulus other than the radion, which generically exists in 5D supergravity. SUSY is broken at the vacuum, which can be regarded as the Scherk-Schwarz SUSY breaking. We also analyze the mass spectrum and discuss some phenomenological aspects.