Single-Pion Production in pp Collisions at 0.95 GeV/c (II)

The single-pion production reactions $pp\to d\pi^+$, $pp\to np\pi^+$ and $pp\to pp\pi^0$ were measured at a beam momentum of 0.95 GeV/c ($T_p \approx$ 400 MeV) using the short version of the COSY-TOF spectrometer. The central calorimeter provided particle identification, energy determination and neutron detection in addition to time-of-flight and angle measurements from other detector parts. Thus all pion production channels were recorded with 1-4 overconstraints. Main emphasis is put on the presentation and discussion of the $np\pi^+$ channel, since the results on the other channels have already been published previously. The total and differential cross sections obtained are compared to theoretical calculations. In contrast to the $pp\pi^0$ channel we find in the $np\pi^+$ channel a strong influence of the $\Delta$ excitation already at this energy close to threshold. In particular we find a $(3 cos^2\Theta + 1)$ dependence in the pion angular distribution, typical for a pure s-channel $\Delta$ excitation and identical to that observed in the $d\pi^+$ channel. Since the latter is understood by a s-channel resonance in the $^1D_2$ $pn$ partial wave, we discuss an analogous scenario for the $pn\pi^+$ channel

The Fast Read-out System for the MAPMTs of COMPASS RICH-1

A fast readout system for the upgrade of the COMPASS RICH detector has been developed and successfully used for data taking in 2006 and 2007. The new readout system for the multi-anode PMTs in the central part of the photon detector of the RICH is based on the high-sensitivity MAD4 preamplifier-discriminator and the dead-time free F1-TDC chip characterized by high-resolution. The readout electronics has been designed taking into account the high photon flux in the central part of the detector and the requirement to run at high trigger rates of up to 100 kHz with negligible dead-time. The system is designed as a very compact setup and is mounted directly behind the multi-anode photomultipliers. The data are digitized on the frontend boards and transferred via optical links to the readout system. The read-out electronics system is described in detail together with its measured performances.Comment: Proceeding of RICH2007 Conference, Trieste, Oct. 2007. v2: minor change

Technical Design Report for the PANDA Solenoid and Dipole Spectrometer Magnets

This document is the Technical Design Report covering the two large spectrometer magnets of the PANDA detector set-up. It shows the conceptual design of the magnets and their anticipated performance. It precedes the tender and procurement of the magnets and, hence, is subject to possible modifications arising during this process.Comment: 10 pages, 14MB, accepted by FAIR STI in May 2009, editors: Inti Lehmann (chair), Andrea Bersani, Yuri Lobanov, Jost Luehning, Jerzy Smyrski, Technical Coordiantor: Lars Schmitt, Bernd Lewandowski (deputy), Spokespersons: Ulrich Wiedner, Paola Gianotti (deputy

Two-Pion Production in Proton-Proton Collisions with Polarized Beam

The two-pion production reaction $\vec{p}p\to pp\pi^+\pi^-$ was measured with a polarized proton beam at $T_p \approx$ 750 and 800 MeV using the short version of the COSY-TOF spectrometer. The implementation of a delayed pulse technique for Quirl and central calorimeter provided positive $\pi^+$ identification in addition to the standard particle identification, energy determination as well as time-of-flight and angle measurements. Thus all four-momenta of the emerging particles could be determined with 1-4 overconstraints. Total and differential cross sections as well as angular distributions of the vector analyzing power have been obtained. They are compared to previous data and theoretical calculations. In contrast to predictions we find significant analyzing power values up to $A_y$ = 0.3

Pattern recognition and PID for COMPASS RICH-1

A package for pattern recognition and PID by COMPASS RICH-1 has been developed and used for the analysis of COMPASS data collected in the years 2002 to 2004, and 2006-2007 with the upgraded RICH-1 photon detectors. It has allowed the full characterization of the detector in the starting version and in the upgraded one, as well as the PID for physics results. We report about the package structure and algorithms, and the detector characterization and PID results.Comment: 4 pages, 4 figures,to appear in the proceedings of 6th International Workshop on Ring Imaging Cherenkov Counters (RICH 2007), Trieste, Italy, 15-20 Oct 200

Physics Performance Report for PANDA: Strong Interaction Studies with Antiprotons

To study fundamental questions of hadron and nuclear physics in interactions of antiprotons with nucleons and nuclei, the universal PANDA detector will be built. Gluonic excitations, the physics of strange and charm quarks and nucleon structure studies will be performed with unprecedented accuracy thereby allowing high-precision tests of the strong interaction. The proposed PANDA detector is a state-of-the art internal target detector at the HESR at FAIR allowing the detection and identification of neutral and charged particles generated within the relevant angular and energy range. This report presents a summary of the physics accessible at PANDA and what performance can be expected.Comment: 216 page