Results on CP Violation from the NA48 experiment at CERN

In this article the current status and latest results of the NA48 experiment at CERN are given. We present in more details the analysis performed for the Re(e'/e) measurement with the combined statistics accumulated during the 1998 and 1999 data periods. Reviewing the NA48 rare decay program, we select to underline the new results on the branching ratio and the A_v factor for the decay KL->pi0gg and the KL->pi+pi-e+e- CP violating decay. This article is the contribution to the Proceedings of the Lepton-Photon Conference held in Roma, July 23-29 2001.Comment: 13 pages, 11 figures, contribution to the Lepton-Photon 2001 Conference Proceedings -ne

The simultaneous long- and short-lived neutral kaon beams for experiment NA48

Simultaneous, nearly-collinear beams of long- and short-lived neutral kaons are an essential feature of the precision CP-violation experiment NA48 *) at the SPS. The present report describes the design and performance of these beams in relation to the requirements of the experiment

The simultaneous and nearly-collinear K0K^{0} beams for experiment NA48

A system of simultaneous and nearly-collinear beams of long- and short-lived neutral kaons has been installed and extensively studied. These beams form an integral part of the NA48 experiment at the CERN SPS, which aims to study direct CP-violation. The beam splitting is achieved by a novel application of a bent silicon crystal. The principles and design of these beams, as well as their performance are described

Pseudorapidity Distribution of Charged Particles in PbarP Collisions at root(s)= 630GeV

Using a silicon vertex detector, we measure the charged particle pseudorapidity distribution over the range 1.5 to 5.5 using data collected from PbarP collisions at root s = 630 GeV. With a data sample of 3 million events, we deduce a result with an overall normalization uncertainty of 5%, and typical bin to bin errors of a few percent. We compare our result to the measurement of UA5, and the distribution generated by the Lund Monte Carlo with default settings. This is only the second measurement at this level of precision, and only the second measurement for pseudorapidity greater than 3.Comment: 9 pages, 5 figures, LaTeX format. For ps file see http://hep1.physics.wayne.edu/harr/harr.html Submitted to Physics Letters

Photon emission by an ultra-relativistic particle channeling in a periodically bent crystal

This paper is devoted to a detailed analysis of the new type of the undulator radiation generated by an ultra-relativistic charged particle channeling along a crystal plane, which is periodically bent by a transverse acoustic wave, as well as to the conditions limiting the observation of this phenomenon. This mechanism makes feasible the generation of electromagnetic radiation, both spontaneous and stimulated, emitted in a wide range of the photon energies, from X- up to gamma-rays

The Influence of Radiation Damage on the Deflection of High-Energy Beams in Bent Silicon Crystals

Experimental results obtained for deflection of 450 GeV/c protons channeling along the {111} planes in a bent, strongly irradiated silicon crystal are presented. A comparison between the deflection efficiencies in irradiated areas and non-irradiated areas in the crystal shows that irradiation by 2.4 · 1020 protons/cm2 leads to a reduction of around 30 % in deflection efficiency. As a consequence, beam-splitting and extraction from an accelerator by means of a bent crystal are feasible solutions at high energies even for intense beams and during long periods

Coherent Pair Production by Photons in the 20-170 GeV Energy Range Incident on Crystals and Birefringence

The cross section for coherent pair production by linearly polarised photons in the 20-170 GeV energy range was measured for photon aligned incidence on ultra-high quality diamond and germanium crystals. The theoretical description of coherent bremsstrahlung and coherent pair production phenomena is an area of active theoretical debate and development. However, under our experimental conditions, the theory predicted the combined cross section and polarisation experimental observables very well indeed. In macroscopic terms, our experiment measured a birefringence effect in pair production in a crystal. This study of this effect also constituted a measurement of the energy dependent linear polarisation of photons produced by coherent bremsstrahlung in aligned crystals. New technologies for manipulating high energy photon beams can be realised based on an improved understanding of QED phenomena at these energies. In particular, this experiment demonstrates an efficient new polarimetry technique. The pair production measurements were done using two independent methods simultaneously. The more complex method using a magnet spectrometer showed that the simpler method using a multiplicity detector was also viable.Comment: 10 pages, 13 figures, 1 table, REVTeX4 two column, Version for publicatio