17419321
Two-loop renormalization of gaugino mass in supersymmetric gauge model
Abstract We study the two-loop renormalization group equation for the running gaugino mass in the supersymmetric gauge theory. We find that both in the MS and DR renormalization schemes, the well-known proportionality of the runnings of the gaugino mass and the gauge coupling constant is violated at the two-loop order, even in models with vector supermultiplets only. The scheme dependence of the running gaugino mass is clarified.
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 $\tilde b$.
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
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.
7557738
PROBING THE NATURE OF COMPACTIFICATION WITH KALUZA-KLEIN EXCITATIONS AT THE LARGE HADRON COLLIDER
Abstract It is shown that the nature of compactification of extra dimensions in theories of large radius compactification can be explored in several processes at the Large Hadron Collider (LHC). Specifically it is shown that the characteristics of the Kaluza–Klein (KK) excitations encode information on the nature of compactification, i.e., on the number of compactified dimensions as well as on the type of compactification, e.g., of the specific orbifold compactification. The most dramatic signals arise from the interference pattern involving the exchange of the Standard Model spin 1 bosons ( γ and Z ) and their Kaluza–Klein modes in the dilepton final state pp → l + l − X . It is shown that LHC with 100 fb −1 of luminosity can discover Kaluza–Klein modes up to compactification scales of ≈6 TeV as well as identify the nature of compactification. Effects of the Kaluza–Klein excitations of the W boson and of the gluon are also studied. Exhibition of these phenomena is given for the case of one extra dimension and for the case of two extra dimensions with Z 2 × Z 2 , Z 3 , and Z 6 orbifold compactifications.
119288533
Reheating processes after Starobinsky inflation in old-minimal supergravity
A bstractWe study reheating processes and its cosmological consequences in the Starobinsky model embedded in the old-minimal supergravity. First, we consider minimal coupling between the gravity and matter sectors in the higher curvature theory, and transform it to the equivalent standard supergravity coupled to additional matter superfields. We then discuss characteristic decay modes of the inflaton and the reheating temperature TR. Considering a simple model of supersymmetry breaking sector, we estimate gravitino abundance from inflaton decay, and obtain limits on the masses of gravitino and supersymmetry breaking field. We find TR ≃ 1.0 × 109 GeV and the allowed range of gravitino mass as 104 GeV ≲ m3/2 ≲ 105 GeV, assuming anomaly-induced decay into the gauge sector as the dominant decay channel.