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The problems of the standard model are reviewed and the motivations for introducing supersymmetry are discussed. The basic theory behind supersymmetry is described briefly, followed by an introduction of two realistic supersymmetric models; the Minimal SuperSymmetric Model (MSSM) and its proposed extension, the NMSSM. Some details of the NMSSM are stated and some constraints on parameters are desc
A selection of the latest and most frequently used PDFs is incorporated in Pythia8, including the MC-adapted PDFs from the MSTW and CTEQ collaborations. This thesis examines the differences in PDFs as well as the effect they have on results of simulations. The results are also compared to data collected by the CDF experiment.
In this thesis, a new model for diffractive proton-proton collisions is presented. Interpreting protons as systems of many partons, we treat diffraction in terms of elastic interactions between the partons of the colliding protons. Parton emission and absorption are employed as the mechanism that in the context of a diffractive event can stabilize excited protons by reshuffling parton momenta and
Particle collisions are an essential component to the research methodology of particle physics. These investigations are not only conducted in experimental laboratories but also through programs such as PYTHIA that simulate a collision or ``event" and then compare its results to known experimental data. This thesis aims to investigate the energy dependence of parameters used in PYTHIA's A
Spectra of hot (type B) stars obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE) satellite in the region 1000-1200
In the collinear factorization scheme the minijet cross section diverges for small k [perpendicular]. In the k[perpendicular]-factorization formalism this divergence is avoided, and it is possible to calculate the number of minijets and the E[perpendicular]-flow exclusively from HERA data, without reliance on a phenomenological soft cutoff. The hadron multiplicity is very sensitive to non-perturba
We present the results of a search for relations between observables that are independent of the Chiral Perturbation Theory (ChPT) Next-to-Next-to-Leading Order (NNLO) Low-Energy Constants (LECs). We have found some relations between observables in $\pi\pi$, $\pi K$ scattering and $K_{l4}$ decay which have been evaluated numerically using the old fit (fit 10 in~\cite{Amoros:2001cp}) of the NLO LEC
We present work going on calculating the kaon BK parameter in the 1/Nc expansion. The goal of this work is to analyze analytically in the presence of chiral corrections this phenomenologically very important parameter. We present the method used and preliminary results for the chiral limit value for which we get the invariant BKchi=0.29 +- 0.15. We also give some analytical indications of why the
Different hadronization effects in high energy interactions are investigated. The frame-work is the Lund model for the strong interaction. A model for baryon production in jet fragmentation is presented and extended to baryon remnant fragmentation in deep inelastic scattering and hadron--hadron collisions. Observables designed to probe hadronization effects on pt correlations are show
I present the status of the ThePEG project for creating a common platform for implementing C++ event generators. I also describe briefly the status of the new versions of HERWIG++ and Ariadne which are implemented using this framework.
In this paper we describe a formalism for generating exclusive final states in diffractive excitation, based on the optical analogy where diffraction is fully determined by the absorption into inelastic channels. The formalism is based on the Good--Walker formalism for diffractive excitation, and it is assumed that the virtual parton cascades represent the diffractive eigenstates defined by a defi
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We review the status of the hadronic light-by-light contribution to the muon anomalous magnetic moment and critically compare recent calculations. We also study in detail which momentum regions the pi0 exchange main contribution originates. We also argue that amu{light-by-light} = (11 pm 4) times 10-10 encompasses the present understanding of this contribution and comment on some direct
These are the proceedings of the workshop on ``Effective Field Theories in Nuclear, Particle and Atomic Physics'' held at the Physikzentrum Bad Honnef of the Deutsche Physikalische Gesellschaft, Bad Honnef, Germany from December 13 to 17, 2005. The workshop concentrated on Effective Field Theory in many contexts. A first part was concerned with Chiral Perturbation Theory in its various settings an
