Ordering variable for parton showers

The parton splittings in a parton shower are ordered according to an ordering variable, for example the transverse momentum of the daughter partons relative to the direction of the mother, the virtuality of the splitting, or the angle between the daughter partons. We analyze the choice of the ordering variable and conclude that one particular choice has the advantage of factoring softer splittings from harder splittings graph by graph in a physical gauge.Comment: 28 pages, 5 figure

The effect of waste logistics on the environmental impact of road transport

Nowadays we should consider the wastes in a much wider sense as an expedient raw material source. From a logistic point of view the fact that the flows of the second raw materials are not constant in the waste logistics systems is a challenge. The quantity of the wastes of production, consumption and recycling are varying in time and space. The arising municipal wastes usually can be found in smaller items then previously, have relatively more utilization opportunity when they appear separated on the refuse dumps. Optimal cargos should be organized by the environmental aspect of road transport services. Recently road transport is one of the main polluters. With the internalisation of external costs of road transportation the price of waste as basis of secondary raw material will increase. The article describes these problems and the methods of which can be used for the solution

Some consequences of GUP induced ultraviolet wavevector cutoff in one-dimensional Quantum Mechanics

A projection method is proposed to treat the one-dimensional Schrodinger equation for a single particle when the Generalized Uncertainty Principle (GUP) generates an ultraviolet (UV) wavevector cutoff. The existence of a unique coordinate representation called the naive one is derived from the one-parameter family of discrete coordinate representations. In this bandlimited Quantum Mechanics a continuous potential is reconstructed from discrete sampled values observed by means of a particle in maximally localized states. It is shown that bandlimitation modifies the speed of the center and the spreading time of a Gaussian wavepacket moving in free space. Indication is found that GUP accompanied by bandlimitation may cause departures of the low-lying energy levels of a particle in a box from those in ordinary Quantum Mechanics much less suppressed than commonly thought when GUP without bandlimitation is in work.Comment: 20 pages, 2 figure

Phase structure of the O(2)O(2) ghost model with higher-order gradient term

The phase structure and the infrared behaviour of the Euclidean 3-dimensional $O(2)$ symmetric ghost scalar field model with higher-order derivative term has been investigated in Wegner and Houghton's renormalization group framework. The symmetric phase in which no ghost condensation occurs and the phase with restored symmetry but with a transient presence of a ghost condensate have been identified. Finiteness of the correlation length at the phase boundary hints to a phase transition of first order. The results are compared with those for the ordinary $O(2)$ symmetric scalar field model.Comment: 15 pages, 13 figure

Multi-jet cross sections in deep inelastic scattering at next-to-leading order

We present the perturbative prediction for three-jet production cross section in DIS at the NLO accuracy. We study the dependence on the renormalization and factorization scales of exclusive three-jet cross section. The perturbative prediction for the three-jet differential distribution as a function of the momentum transfer is compared to the corresponding data obtained by the H1 collaboration at HERA.Comment: 5 pages, 3 figure