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Xiangdong Ji
Physics , 1995,
Abstract: In this talk, I focus on the quark-gluon structure of hadrons probed using high-energy hadron beams. I start with a brief review on recent major achievements in measuring parton distributions of the nucleon, pion, and kaon, with hadron facilities at CERN and FNAL\@. Then I discuss a number of outstanding questions and interesting physics issues in the field, and point out their intellectual impact on nuclear physics as a whole. While advocating a continuing exploitation of hadron beams at CERN and FNAL, I strongly emphasize the role of a polarized RHIC, where a major nuclear physics program on the structure of hadrons can thrive.
The COMPASS Setup for Physics with Hadron Beams  [PDF]
Ph. Abbon,C. Adolph,R. Akhunzyanov,Yu. Alexandrov,M. G. Alexeev,G. D. Alexeev,A. Amoroso,V. Andrieux,V. Anosov,A. Austregesilo,B. Badelek,F. Balestra,J. Barth,G. Baum,R. Beck,Y. Bedfer,A. Berlin,J. Bernhard,K. Bicker,E. R. Bielert,J. Bieling,R. Birsa,J. Bisplinghoff,M. Bodlak,M. Boer,P. Bordalo,F. Bradamante,C. Braun,A. Bressan,M. Buechele,E. Burtin,L. Capozza,P. Ciliberti,M. Chiosso,S. U. Chung,A. Cicuttin,M. Colantoni,D. Cotte,M. L. Crespo,Q. Curiel,T. Dafni,S. Dalla Torre,S. S. Dasgupta,S. Dasgupta,O. Yu. Denisov,D. Desforge,A. M. Dinkelbach,S. V. Donskov,N. Doshita,V. Duic,W. Duennweber,D. Durand,M. Dziewiecki,A. Efremov,C. Elia,P. D. Eversheim,W. Eyrich,M. Faessler,A. Ferrero,M. Finger,M. Finger jr.,H. Fischer,C. Franco,N. du Fresne von Hohenesche,J. M. Friedrich,V. Frolov,L. Gatignon,F. Gautheron,O. P. Gavrichtchouk,S. Gerassimov,R. Geyer,A. Giganon,I. Gnesi,B. Gobbo,S. Goertz,M. Gorzellik,S. Grabmueller,A. Grasso,M. Gregori,B. Grube,T. Grussenmeyer,A. Guskov,F. Haas,D. von Harrach,D. Hahne,R. Hashimoto,F. H. Heinsius,F. Herrmann,F. Hinterberger,Ch. Hoeppner,N. Horikawa,N. d'Hose,S. Huber,S. Ishimoto,A. Ivanov,Yu. Ivanshin,T. Iwata,R. Jahn,V. Jary,P. Jasinski,P. Joerg,R. Joosten,E. Kabuss,B. Ketzer,G. V. Khaustov,Yu. A. Khokhlov,Yu. Kisselev,F. Klein,K. Klimaszewski,J. H. Koivuniemi,V. N. Kolosov,K. Kondo,K. Koenigsmann,I. Konorov,V. F. Konstantinov,A. M. Kotzinian,O. Kouznetsov,M. Kraemer,Z. V. Kroumchtein,N. Kuchinski,R. Kuhn,F. Kunne,K. Kurek,R. P. Kurjata
Physics , 2014, DOI: 10.1016/j.nima.2015.01.035
Abstract: The main characteristics of the COMPASS experimental setup for physics with hadron beams are described. This setup was designed to perform exclusive measurements of processes with several charged and/or neutral particles in the final state. Making use of a large part of the apparatus that was previously built for spin structure studies with a muon beam, it also features a new target system as well as new or upgraded detectors. The hadron setup is able to operate at the high incident hadron flux available at CERN. It is characterised by large angular and momentum coverages, large and nearly flat acceptances, and good two and three-particle mass resolutions. In 2008 and 2009 it was successfully used with positive and negative hadron beams and with liquid hydrogen and solid nuclear targets. This article describes the new and upgraded detectors and auxiliary equipment, outlines the reconstruction procedures used, and summarises the general performance of the setup.
Test Beams and Polarized Fixed Target Beams at the NLC  [PDF]
Lewis Keller,Rainer Pitthan,Sayed Rokni,Kathleen Thompson,Yury Kolomenski
Physics , 2001, DOI: 10.1063/1.1394415
Abstract: A conceptual program to use NLC beams for test beams and fixed target physics is described. Primary undisrupted polarized beams would be the most simple to use, but for NLC, the disrupted beams are of good enough quality that they could also be used, after collimation of the low energy tails, for test beams and fixed target physics. Pertinent issues are: what is the compelling physics, what are the requirements on beams and running time, and what is the impact on colliding beam physics running. A list of physics topics is given; one topic Moller Scattering is treated in more depth.
Specific instrumentation and diagnostics for high-intensity hadron beams  [PDF]
Kay Wittenburg
Physics , 2013, DOI: 10.5170/CERN-2013-001.251
Abstract: An overview of various typical instruments used for high-intensity hadron beams is given. In addition, a few important diagnostic methods are discussed which are quite special for these kinds of beams.
Characterizing New Physics with Polarized Beams at High-Energy Hadron Colliders  [PDF]
Benjamin Fuks,Josselin Proudom,Juan Rojo,Ingo Schienbein
Physics , 2014, DOI: 10.1007/JHEP05(2014)045
Abstract: The TeV energy region is currently being explored by both the ATLAS and CMS experiments of the Large Hadron Collider and phenomena beyond the Standard Model are extensively searched for. Large fractions of the parameter space of many models have already been excluded, and the ranges covered by the searches will certainly be increased by the upcoming energy and luminosity upgrades. If new physics has to be discovered in the forthcoming years, the ultimate goal of the high-energy physics program will consist of fully characterizing the newly-discovered degrees of freedom in terms of properties such as their masses, spins and couplings. The scope of this paper is to show how the availability of polarized beams at high-energy proton-proton colliders could yield a unique discriminating power between different beyond the Standard Model scenarios. We first discuss in a model-independent way how this discriminating power arises from the differences between polarized and unpolarized parton distribution functions. We then demonstrate how polarized beams allow one not only to disentangle different production mechanisms giving the same final-state signature, but also to obtain information on the parameters of the hypothetical new physics sector of the theory. This is illustrated in the case of a particular class of scenarios leading to monotop production. We consider three specific models that could produce a monotop signature in unpolarized proton collisions, and show how they could be distinguished by means of single- and double-spin asymmetries in polarized collisions. Our results are presented for both the Large Hadron Collider operating at a center-of-mass energy of 14 TeV and a recently proposed Future Circular Collider assumed to collide protons at a center-of-mass energy of 100 TeV.
Color Coherent Phenomena with Hadron Beams  [PDF]
Mark Strikman,Michail Zhalov
Physics , 1999, DOI: 10.1016/S0375-9474(00)00084-1
Abstract: We outline major ideas involved in discussion of color coherence phenomena (CCP) at intermediate energies. We point out that the recent advances in calculating cross sections of hard exclusive processes off light nuclei allow to use the lightest nuclei for sensitive tests of CCP. Consistency of the results of the measurements of color transparency in quasielastic A(p,2p) and A(e,e$'$p) processes is emphasized. Evidence for presence of significant color fluctuations in nucleons and pions emerging from the study of diffractive processes is summarized. A new class of hard processes leading to three particle final state is suggested for electron and hadron projectiles. A number of new experiments are suggested to probe color fluctuations in hadrons.
Time evolution of the luminosity of colliding heavy-ion beams in BNL Relativistic Heavy Ion Collider and CERN Large Hadron Collider  [PDF]
R. Bruce,M. Blaskiewicz,W. Fischer,J. M. Jowett
Physics , 2010, DOI: 10.1103/PhysRevSTAB.13.091001
Abstract: We have studied the time evolution of the heavy ion luminosity and bunch intensities in the Relativistic Heavy Ion Collider (RHIC), at BNL, and in the Large Hadron Collider (LHC), at CERN. First, we present measurements from a large number of RHIC stores (from Run 7), colliding 100 GeV/nucleon Au beams without stochastic cooling. These are compared with two different calculation methods. The first is a simulation based on multi-particle tracking taking into account collisions, intrabeam scattering, radiation damping, and synchrotron and betatron motion. In the second, faster, method, a system of ordinary differential equations with terms describing the corresponding effects on emittances and bunch populations is solved numerically. Results of the tracking method agree very well with the RHIC data. With the faster method, significant discrepancies are found since the losses of particles diffusing out of the RF bucket due to intrabeam scattering are not modeled accurately enough. Finally, we use both methods to make predictions of the time evolution of the future Pb beams in the LHC at injection and collision energy. For this machine, the two methods agree well.
The Hadron Hose: Continuous Toroidal Focusing for Conventional Neutrino Beams  [PDF]
J. Hylen,D. Bogert,R. Ducar,V. Garkusha,J. Hall,C. Jensen,S. E. Kopp,M. Kostin,A. Lyukov,A. Marchionni,M. May,M. D. Messier,R. Milburn,F. Novoskoltsev,M. Proga,D. Pushka,W. Smart,J. Walton,V. Zarucheisky,R. M. Zwaska
Physics , 2002, DOI: 10.1016/S0168-9002(02)01988-5
Abstract: We have developed a new focusing system for conventional neutrino beams. The ``Hadron Hose'' is a wire located in the meson decay volume, downstream of the target and focusing horns. The wire is pulsed with high current to provide a toroidal magnetic field which continuously focuses mesons. The hose increases the neutrino event rate and reduces differences between near-field and far-field neutrino spectra for oscillation experiments. We have studied this device as part of the development of the Neutrinos at the Main Injector (NuMI) project, but it might also be of use for other conventional neutrino beams.
High-quality ion beams by irradiating a nano-structured target with a petawatt laser pulse  [PDF]
M. Grech,S. Skupin,R. Nuter,L. Gremillet,E. Lefebvre
Physics , 2009, DOI: 10.1088/1367-2630/11/9/093035
Abstract: We present a novel laser based ion acceleration scheme, where a petawatt circularly polarized laser pulse is shot on an ultra-thin (nano-scale) double-layer target. Our scheme allows the production of high-quality light ion beams with both energy and angular dispersion controllable by the target properties. We show that extraction of all electrons from the target by radiation pressure can lead to a very effective two step acceleration process for light ions if the target is designed correctly. Relativistic protons should be obtainable with pulse powers of a few petawatt. Careful analytical modeling yields estimates for characteristic beam parameters and requirements on the laser pulse quality, in excellent agreement with one and two-dimensional Particle-in Cell simulations.
Hadron production measurements to constrain accelerator neutrino beams  [PDF]
Alexander Korzenev
Physics , 2014,
Abstract: A precise prediction of expected neutrino fluxes is required for a long-baseline accelerator neutrino experiment. The flux is used to measure neutrino cross sections at the near detector, while at the far detector it provides an estimate of the expected signal for the study of neutrino oscillations. In the talk several approaches to constrain the neutrino flux are presented. The first is the traditional one when an interaction chain for the neutrino parent hadrons is stored to be weighted later with real measurements. In this approach differential hadron cross sections are used which, in turn, are measured in ancillary hadron production experiments. The approach is certainly model dependent because it requires an extrapolation to different incident nucleon momenta assuming x_F scaling as well as extrapolation between materials having different atomic numbers. In the second approach one uses a hadron production yields off a real target exploited in the neutrino beamline. Yields of neutrino parent hadrons are parametrized at the surface of the target, thus one avoids to trace the particle interaction history inside the target. As in the case of the first approach, a dedicated ancillary experiment is mandatory. Recent results from the hadron production experiments - NA61/SHINE at CERN (measurements for T2K) and MIPP at Fermilab (measurements for NuMI) - are reviewed.
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