We consider a model of transverse momentum production in which nonperturbative smearing takes place throughout the perturbative evolution, by a simple modification to an initial state parton shower algorithm. Using this as the important non-perturbative ingredient, we get a good fit to data over a wide range of energy. Combining it with the non-perturbative masses and cutoffs that are a feature...

I use QCD sum rule ideas to construct models for generalized parton distributions. To this end, the perturbative parts of QCD sum rules for the pion and nucleon electromagnetic form factors are interpreted in terms of GPDs and two models are discussed. One of them takes the double Borel transform at adjusted value of the Borel parameter as a model for nonforward parton densities, and another is...

We evaluate the impact of recent developments in hadron phenomenology on extracting possible fundamental tensor interactions beyond the standard model. We show that a novel class of observables, including the chiral-odd generalized parton distributions, and the transversity parton distribution function can contribute to the constraints on this quantity. Experimental extractions of the tensor ha...

ACCESSING THE SPACE–TIME DEVELOPMENT OF HEAVY–ION COLLISIONS WITH THEORY AND EXPERIMENT By David Alan Brown In this thesis we discuss ways to access the space-time development of heavy-ion reactions using both theory and experiment. From the theoretical side, we discuss modeling ultra-relativistic, parton-dominated, heavy-ion reactions. This discussion is broken into a discussion of transport-l...

We propose a new hadronization mechanism, jet-fluid string (JFS) formation and decay, to understand observables in intermediate to high-pT regions comprehensively. In the JFS model, hard partons produced in jet lose their energy in traversing the QGP fluid, which is described by fully three-dimensional hydrodynamic simulations. When a jet parton escapes from the QGP fluid, it picks up a partner...

The parametrisation of the real photon structure function F γ 2 in the low Q 2, low x region is formulated. It includes the VMD contribution and the QCD improved parton model component suitably extrapolated to the low Q2 region. We study the sensitivity of our predictions on the extrapolation of the QCD improved parton model part. The parametrisation describes reasonably well existing experimen...

A mechanism for locally density-dependent dynamic parton rearrangement and fusion has been implemented into the Ultrarelativistic Quantum Molecular Dynamics (UrQMD) approach. The same mechanism has been previously built in the Quark Gluon String Model (QGSM). This rearrangement and fusion approach based on parton coalescence ideas enables the description of multi-particle interactions, namely 3...

The p T-spectra for direct J/ψ and ψ ′ in hadroproduction at Tevatron energy have been calculated based on NRQCD formalism and fragmentation approximation in the collinear parton model and k T-factorization approach. We have described the CDF data and obtained a good agreement between the predictions obtained in the parton model and k T-factorization approach. We performed the calculations usin...

We present the general formalism required to derive generalized parton distributions within a convolution model where the bare nucleon is dressed by its virtual meson cloud. In the one-meson approximation the Fock states of the physical nucleon are expanded in a series involving a bare nucleon and two-particle, meson-baryon, states. The baryon is assumed here to be either a nucleon or a ∆ descr...