117724729
Particle spectra and interferometry results from NA44
22084508
Status of zero degree calorimeter for CMS experiment
The Zero Degree Calorimeter (ZDC) is integral part of the CMS experiment, especially, for heavy ion studies. The design of the ZDC includes two independent calorimeter sections: an electromagnetic section and a hadronic section. Sampling calorimeters using tungsten and quartz fibers have been chosen for the energy measurements. An overview of the ZDC is presented along with a current status of calorimeter’s preparation for Day 1 of LHC.
119203216
Performance of the combined zero degree calorimeter for CMS
The combined zero degree calorimeter (ZDC) is a combination of sampling quartz/tungsten electromagnetic and hadronic calorimeters. Two identical combined calorimeters are located in the LHC tunnel at CERN at the straight section ~140 m on each side of the CMS interaction vertex and between the two beam pipes. They will detect very forward |?| ? 8.5 photons and neutrons. ZDC information can be used for a variety of physics measurements as well as improving the collision centrality determination in heavy-ion collisions. Results are presented for ZDC performance studies with the CERN SPS H2 test beam.
118432204
Particle spectra and HBT results from NA44
Recent results on baryon spectra and interferometry from NA44 are compared to RQMD and a hydrodynamical model. The importance of flow and rescattering on the rapidity and transverse mass distributions is discussed. The yields of protons and antiprotons are compared as a function of system, rapidity and multiplicity.
118726538
Detecting Elastic pp Scattering by Radiative Photons in CMS at the LHC
Photon bremsstrahlung is studied for identifying elastic proton-proton interactions in the CMS experiment at the LHC. In addition to measurement of the elastic pp cross section (assuming that the elastic slope is known) the bremsstrahlung photons will allow evaluation of the total pp cross section, luminosity and alignment of the Zero Degree Calorimeters (ZDCs).
118972646
Reaction dynamics and multifragmentation in Fermi energy heavy ion reactions
The reaction systems, 64Zn + 58Ni, 64Zn + 92Mo, 64Zn + 197Au, at 26A, 35A and 47A MeV, have been studied both in experiments with a 4$\pi$ detector array, NIMROD, and with Antisymmetrized Molecular Dynamics model calculations employing effective interactions corresponding to soft and stiff equations of state (EOS). Direct experimental observables, such as multiplicity distributions, charge distributions, energy spectra and velocity spectra, have been compared in detail with those of the calculations and a reasonable agreement is obtained. The velocity distributions of $\alpha$ particles and fragments with Z >= 3 show distinct differences in calculations with the soft EOS and the stiff EOS. The velocity distributions of $\alpha$ particle and Intermediate Mass Fragments (IMF's) are best described by the stiff EOS. Neither of the above direct observables nor the strength of the elliptic flow are sensitive to changes in the in-medium nucleon-nucleon (NN) cross sections. A detailed analysis of the central collision events calculated with the stiff EOS revealed that multifragmentation with cold fragment emission is a common feature predicted for all reactions studied here. A possible multifragmentation scenario is presented; after the preequilibrium emission ceases in the composite system, cold light fragments are formed in a hotter gas of nucleons and stay cold until the composite system underdoes multifragmentation. For reaction with 197Au at 47A MeV a significant radial expansion takes place. For reactions with 58Ni and 92Mo at 47A MeV semi-transparency becomes prominent. The differing reaction dynamics drastically change the kinematic characteristics of emitted fragments. This scenario gives consistent explanations for many existing experimental results in the Fermi energy domain.
119536751
The Focusing Disc DIRC for the PANDA experiment at FAIR
The Focusing Disc DIRC is a novel detector concept for particle identification based on the detection of internally-reflected Cherenkov light. A thin synthetic silica disc of 1 m radius will be used as radiator and for light transportation. At the rim LiF bars are foreseen to passively correct for dispersion. Focusing elements map the angles of the propagating photons to spatial positions on the focal plane covered with position sensitive photon detection devices. This novel 2D(+1t) detector concept will contribute to the outstanding particle identification performance of the general purpose PANDA detector. The aims of the PANDA experiment are to address fundamental questions of the strong force, to explore the structure of the nucleon and to search for new matter. The technical design, the current status of the development and recent results from prototype test experiments for the Focusing Disc DIRC are presented.
54846524
Development of DIRC counters for the PANDA Experiment at FAIR
The PANDA experiment at the planned FAIR facility at GSI, Darmstadt, aims at measuring hadronic final states with unprecedented precision and luminosity. Superior particle identification of charged and neutral particles is mandatory to fulfil PANDA's physics aims. DIRC (Detection of Internally Reflected Cherenkov light) counters are foreseen for charged particle identification. A barrel DIRC will cover the central region while a disc DIRC will provide particle identification in the forward region. 
 
Three DIRC concepts differing in the radiator geometry and method for dispersion correction are studied. The barrel DIRC uses a novel imaging system and aims at exploiting a 3D reconstruction to mitigate dispersion effects. Two concepts are investigated for the forward disc DIRC. One concept employs passive dispersion correction and focussing light guides for image reconstruction. Alternatively, time-of-propagation measurements and a wave-length dependent photon detection system are investigated. The three detector designs share common developments such as investigating radiator properties and photon detection systems, and use the same test beam facilities.
123332232
Hard exclusive measurements with a polarised target at HERMES
Hard exclusive measurements at HERMES provide access to the information framework of Generalised Parton Distributions. This framework has the potential to provide a thorough, phenomenological description of the nucleon and aspects of it can be constrained by recent measurements made at the HERMES experiment at DESY. Consideration of meson production allows access to some GPDs, whilst observables from the deeply virtual Compton scattering process can allow a constraint on model parameters which are directly connected to the total angular momentum contribution of up and down quarks to the nucleon's spin.
122525362
DVCS at HERMES: The Recoil Detector & Transverse Target Spin Asymmetries
The HERMES experiment is a large forward angle spectrometer located at the HERA accelerator ring at DESY, Hamburg. One of the most exciting topics studied at HERMES is Deeply Virtual Compton Scattering (DVCS) which is the simplest interaction that provides a gateway for access to Generalised Parton Distributions (GPDs). GPDs are a theoretical framework which can be used to calculate the total angular momentum of the quarks in the nucleon. As such, they provide one piece of the puzzle of nucleonic spin structure. In 2005, HERMES was upgraded in the target region with a Recoil Detector that allows it to make truly exclusive measurements of the DVCS interaction for the first time. The design and construction of the Recoil Detector is discussed herein, in addition to a complete analysis of the Transverse Target Spin Asymmetry (TTSA) in DVCS. Experimental facilities that enable measurement of this asymmetry are rare. The importance of the information on the TTSA from HERMES is made yet greater as the transversely polarised target that allows the asymmetry to be measured has been replaced by an unpolarised target. This was to allow the Recoil Detector to be installed. The final stage of this thesis shows a model-dependent method for constraining the angular momentum of the quarks in the nucleon and speculates as to the other pieces of the spin puzzle.
113252484
Reconstruction methods — PANDA Focussing-Lightguide Disc DIRC
The Focussing-Lightguide Disc DIRC will provide crucial Particle Identification (PID) information for the PANDA experiment at FAIR, GSI. This detector presents a challenging environment for reconstruction due to the complexity of the expected hit patterns and the operating conditions of the PANDA experiment. A discussion of possible methods to reconstruct PID from this detector is given here. Reconstruction software is currently under development.