On The Two Loop Virtual Qcd Corrections To Higgs Boson Pair Production In The Standard Model PDF Download

Weak-scale Supersymmetry (SUSY) is a very well motivated extension of the Standard Model of particle physics. Linking bosons and fermions in an elegant formalism, SUSY allows for a natural solution of the hierarchy problem and for accurate unification of the three Standard Model gauge couplings at a high unification scale. Furthermore, if R-parityis conserved, it provides a convincing candidate for the large amount of cold dark matter observed in the Universe. In the Minimal Supersymmetric Standard Model, this is generally the lightest neutralino, one of the spin-1/2 supersymmetric partners of the electroweak gauge bosons (gauginos) and of the Higgs bosons (Higgsinos), which mix to form four neutral (neutralino) and two charged (chargino) mass eigenstates. After an introduction to supersymmetry, we present the transverse-momentum and threshold resummation formalisms. We then consider the gaugino-pair production at current hadron colliders, i.e. at RHIC, Tevatron and LHC. We study the corresponding effects of polarised initial hadrons and full SUSY-QCD corrections. We finally apply transverse-momentum and threshold re-summations to gaugino-pair production, and show that they have important impact on the transverse-momentum and invariant-mass distributions. Throughout these studies, we also investigate the theoretical uncertainties coming from scale and parton-density function variations.