Related papers: Amplitude and colour evolution
Recent theoretical progress in understanding high-energy scattering beyond the mean field approximation is reviewed. The role of Lorentz invariance and pomeron loops in the evolution, the relation between high-energy QCD and statistical…
We address the problem of decomposing graphs in perturbative QCD into terms associated with particular regions. Motivated by asking how to incorporate next-to-leading order (NLO) QCD corrections in parton-shower algorithms, we require that:…
Recent developments and results on the comparison of gluon to quark jets are discussed. A most important topic is the introduction of explicit energy scales of the jets. The scaling violation of the fragmentation function and the increase…
Parton shower algorithms are key components of theoretical predictions for high-energy collider physics. Work towards more accurate parton shower algorithms is thus pursued along many different avenues. The systematic treatment of…
We consider a general formulation of gradient flow evolution for problems whose natural framework is the one of metric spaces. The applications we deal with are concerned with the evolution of {\it capacitary measures} with respect to the…
Recent developments of the small $x$ CCFM evolution are described, including improvements of the splitting function. The resulting unintegrated gluon densities are used for predictions of hadronic final state measurements like jet…
The quenching of jets (and high-pT particle spectra) observed in heavy-ion collisions is interpreted as due to the energy lost by hard partons crossing the Quark Gluon Plasma. Here we review recent efforts to include in its modeling…
We give an outline of a formalism for the solution of the evolution equations for off-forward parton distributions in leading and next-to-leading orders based on partial conformal wave expansion and orthogonal polynomials reconstruction.
We examine soft gluon physics, focusing on recently developed path integral methods. Two example applications of this technique are presented, namely the classification of soft gluon amplitudes beyond the eikonal approximation, and the…
In the description of the production properties of gauge bosons (W+/W-, Z0, gamma) at colliders, the lowest-order graph normally is not sufficient. The contributions of higher orders can be introduced either by an explicit order-by-order…
We investigate the Q2 evolution of parton distributions at small x values, recently obtained in the case of soft initial conditions. The results are in excellent agreement with deep inelastic scattering experimental data from HERA.
We discuss collective effects like percolation, quark gluon plasma, or string fusion and their effect on the longitudinal development of high energy showers in air. It is shown that iron-air showers could develop more slowly than expected…
We derive the evolution equation for hadronic scattering amplitude at high energy. Our derivation includes the nonlinear effects of finite partonic density in the hadronic wave function as well as the effect of multiple scatterings for…
We study differential intra-jet radiation patterns in jet production at full colour. We present a systematic study of several QCD $2\to 2$ processes and also multi-jet production from a colourless initial state. We examine how subleading…
We study the systematic inclusion of QED corrections in the evolution of parton distributions. O(alpha) corrections modify the evolution equation for parton distributions. They introduce additional parton distributions, like the photon…
The modifications of the angular and transverse momentum distributions of quarks and gluons inside a parton shower due to the presence of a medium are studied within an analytical description that reduces to the modified leading logarithmic…
The merging of matrix elements and parton showers is an established calculational tool for the description of multi-jet final states at hadron colliders. These methods have recently been promoted to next-to-leading order accuracy in the…
The connection between analytic and Monte Carlo calculations of soft gluon emission is reanalyzed in light of recent, theoretical developments in resummation. An alternative Monte Carlo algorithm is suggested which incorporates (1)…
We propose a new evolution equation for the gluon density relevant for the region of small $x_B$. It generalizes the GLR equation and allows deeper penetration in dense parton systems than the GLR equation does. This generalization consists…
We present a Monte Carlo simulation of the perturbative Quantum Chromodynamics (pQCD) shower developing after a hard process embedded in a heavy-ion collision. The main assumption is that the cascade of branching partons traverses a medium…