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AbstractAbstract
[en] The first Regge description of the virtual photon absorption cross section difference Δσ(γ*, N) = [σ1/2(γ*,N) - σ((3)/(2))(γ*, N)] was obtained from a global fit of all the data collected by the experiments measuring spin asymmetries in polarized lepton - polarized nucleon deep inelastic scattering. This work present a phenomenological and a numerical description of all the polarized deep inelastic data (Δσ(γ*, N), gl spin structure function) on the whole measured kinematical range (0.3 GeV2 < Q2 < 70 GeV2, 4 GeV2 < W2 < 300 GeV2). The fit also provide reliable predictions for the photo-production limit through a smooth Q2-transition
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PHOTON 99: 12. international workshop on photon-photon collisions; Freiburg (Germany); 23-27 May 1999; S0920563200001626; Copyright (c) 2000 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
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AbstractAbstract
[en] The so called open-quotes EMC effectclose quotes discovered during the 1980's, has caused a big controversy in the community of nuclear and high energy physicists; during the last ten years, five experiments have been performed in different laboratories and several hundreds of papers about the possible interpretation of the modification of the nucleon structure function inside nuclei have been published. However, from the experimental point of view, the main goal of four experiments (EMC, BCDMS, NMC, FNAL) has been to emphasize the region of low xb, where shadowing effects appear. In the region of valence quarks and nuclear effects (xb > 0.1 - 0.2) the most reliable data presently available are from the SLAC E139 experiment performed in 1983 with only 80 hours of beam time. New precise data in the valence quark region are necessary to measure separate structure functions F2(xb, Q2) and Rlt(xb,Q2) = σl/σt, and to investigate the real A-dependence of the ratio between bound and free-nucleon structure functions which is not completely defined by the SLAC data. Moreover, from the nuclear physics point of view, a measurement on some unexplored nuclei, like 3He and 48Ca, would be of great interest. The intermediate scaling region (0.1 < xb < 0.7) would be accessible at CEBAF if the machine energy will reach 6-8 GeV, as suggested by all the tests performed on the RF cavities. This physics program has been already presented in two letter of intents
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Isgur, N.; Stoler, P. (eds.); Southeastern Universities Research Association, Inc., Newport News, VA (United States); 545 p; Apr 1994; p. 341-346; Workshop on CEBAF at higher energies; Newport News, VA (United States); 14-16 Apr 1994; Also available from OSTI as DE96001410; NTIS; US Govt. Printing Office Dep
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Bianchi, N.
Prospects of hadron and quark physics with electromagnetic probes. Proceedings of the second ELFE workshop on Hadronic Physics1996
Prospects of hadron and quark physics with electromagnetic probes. Proceedings of the second ELFE workshop on Hadronic Physics1996
AbstractAbstract
[en] The Gerasimov-Drell-Hearn (GDH) sum rule is based on a general dispersive relation for the forward Compton scattering. Multipole analysis suggested the possible violation of the sum rule. Some propositions have been made to modify the original GDH expression. An effort is now being made in several laboratories to shred some light on this topic. The purposes of the different planned experiments are briefly presented according to their Q2 range
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D'Hose, N.; Frois, B.; Guichon, P.A.M. (CEA Saclay, 91 - Gif-sur-Yvette (France). Dept. d'Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l'Instrumentation Associee); Pire, B. (Ecole Polytechnique, 91 - Palaiseau (France). Centre de Physique Theorique); Van de Wiele, J. (Institut de Physique Nucleaire, 91 - Orsay (France). Division de Recherche Experimentale); CEA Saclay, 91 - Gif-sur-Yvette (France). Dept. d'Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l'Instrumentation Associee; 186 p; 1996; p. 57-60; 2. ELFE workshop on hadronic physics; Saint Malo (France); 23-27 Sep 1996
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AbstractAbstract
[en] Semi-Inclusive DIS (SIDIS) of high energy leptons on nuclear targets has been used to study the nuclear medium modification of the quark fragmentation function. The possible interpretations and the implications on the parton energy loss are discussed. The first measurement of double-hadron production in deep-inelastic scattering within the nuclear medium is also presented. Nuclear effects on the additional hadron are clearly observed, but with little or no difference among nitrogen, krypton or xenon, and with smaller magnitude than effects seen on previously measured single-hadron multiplicities. The data are compared with models based on partonic energy loss or pre-hadronic scattering, and with a model based on a purely absorptive treatment of the final state interactions. Thus, the double-hadron ratio provides an additional tool for studying modifications of hadronization in nuclear matter
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2. international conference on hard and electromagnetic probes of high-energy nuclear collisions; Pacific Grove, CA (United States); 9-16 Jun 2006; S0375-9474(06)00805-0; Copyright (c) 2006 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
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ELEMENTARY PARTICLES, ELEMENTS, FERMIONS, FLUIDS, GASES, INELASTIC SCATTERING, INTERACTIONS, LEPTON-BARYON INTERACTIONS, LEPTON-HADRON INTERACTIONS, LEPTON-NUCLEON INTERACTIONS, LOSSES, MATTER, MEASURING INSTRUMENTS, NONMETALS, PARTICLE INTERACTIONS, RARE GASES, SCATTERING, SPECTROMETERS, STORAGE RINGS
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AbstractAbstract
[en] Recent results from HERMES and expectations from Jlab in the hadron leptoproduction of nuclei are presented. The possible interpretations in terms of medium modifications of the parton fragmentation function and the implications on the parton energy loss are discussed. (author)
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16 refs.
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ACCELERATORS, BASIC INTERACTIONS, BOSONS, ELECTROMAGNETIC INTERACTIONS, ELEMENTARY PARTICLES, FERMIONS, INELASTIC SCATTERING, INTERACTIONS, LEPTON-BARYON INTERACTIONS, LEPTON-HADRON INTERACTIONS, LEPTON-NUCLEON INTERACTIONS, LINEAR ACCELERATORS, LOSSES, MATTER, MEASURING INSTRUMENTS, NUCLEAR REACTIONS, PARTICLE INTERACTIONS, PARTICLE PRODUCTION, SCATTERING, SPECTROMETERS
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Bianchi, N.
Proceedings of the international symposium on electromagnetic interactions in nuclear and hadron physics2002
Proceedings of the international symposium on electromagnetic interactions in nuclear and hadron physics2002
AbstractAbstract
[en] The production of charged hadrons in semi-inclusive deep inelastic scattering off nuclei has been studied by the HERMES experiment at DESY using 27.5 GeV positrons. A reduction of the multiplicity of charged hadrons and identified charged pions from nuclei relative to that from deuterium has been measured as a function of the relevant kinematic variables ν, z and pt2. A larger reduction of the multiplicity ratio RMh has been found for the krypton with respect to the one previously measured on nitrogen in agreement with a ∼A2/3 power law. Both the krypton and nitrogen data show that the multiplicity ratio is the same for positive and negative pions, while a significant difference is observed between RMh for positive and negative hadrons. This result can be interpreted in terms of a difference between the formation time of protons and pions. It has been also suggested that the observed differences between positive and negative hadrons can be attributed to a different modification of the quark and antiquark fragmentation functions in nuclei. (author)
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Fujiwara, Mamoru; Shima, Tatsushi (Osaka Univ., Ibaraki (Japan). Research Center for Nuclear Physics) (eds.); 725 p; ISBN 981-238-044-2; ; 2002; p. 318-326; International symposium on electromagnetic interactions in nuclear and hadron physics; Osaka (Japan); 4-7 Dec 2001; 12 refs., 6 figs.
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Book
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BOSONS, COMPOSITE MODELS, ELEMENTARY PARTICLES, ELEMENTS, FERMIONS, FLUIDS, GASES, HADRONS, INELASTIC SCATTERING, INTERACTIONS, LEPTON-BARYON INTERACTIONS, LEPTON-HADRON INTERACTIONS, LEPTON-NUCLEON INTERACTIONS, MATHEMATICAL MODELS, MESONS, NONMETALS, NUCLEAR REACTIONS, PARTICLE INTERACTIONS, PARTICLE MODELS, PSEUDOSCALAR MESONS, RARE GASES, SCATTERING
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AbstractAbstract
[en] The Frascati-Genova collaboration proposes to measure the total photonuclear cross section on a wide range of nuclei between 500 MeV and 2 GeV, to obtain informations on the interaction of baryon resonances with nucleons and on the onset of the shadowing effect. The experiment could be performed in the Hall B as soon as the tagging facility will be ready and before the end of the installation of the CLAS spectrometer. The requirements for the photon beam, like maximum energy, intensity and beam definition, are not so strong so that the experiment would also be a good first test of the tagged photon facility
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1992 Continuous Electron Beam Accelerator Facility (CEBAF) summer workshop; Newport News, VA (United States); 15-19 Jun 1992; CONF-9206203--
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ACCELERATORS, ACTINIDES, ALKALINE EARTH METALS, CALCULATION METHODS, ELEMENTARY PARTICLES, ELEMENTS, ENERGY RANGE, FERMIONS, GEV RANGE, HADRONS, HYDROGEN ISOTOPES, ISOTOPES, LIGHT NUCLEI, LINEAR ACCELERATORS, MEASURING INSTRUMENTS, METALS, MEV RANGE, NONMETALS, NUCLEAR REACTIONS, NUCLEI, ODD-ODD NUCLEI, STABLE ISOTOPES
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AbstractAbstract
[en] Recent results from HERMES in the hadron leptoproduction off nuclei are presented. The possible interpretations in terms of medium modifications of the parton fragmentation function and the implications on the parton energy loss and the hadron formation time are discussed. (author)
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20. CFIF Fall Workshop. Nuclear dynamics: from quarks to nuclei; Lisbon (Portugal); 31 Oct - 2 Nov 2002
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Few-Body Systems. Supplementum; ISSN 0177-8811; ; v. 15; p. 99-104
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Bianchi, N.
Mesons and nuclei at intermediate energies. International conference. Book of abstracts1994
Mesons and nuclei at intermediate energies. International conference. Book of abstracts1994
AbstractAbstract
[en] Short communication
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Joint Inst. for Nuclear Research, Dubna (Russian Federation); 126 p; 1994; p. 65; JINR; Dubna (Russian Federation); International conference on mesons and nuclei at intermediate energies (M and N'94); Dubna (Russian Federation); 3-7 May 1994
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Miscellaneous
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AbstractAbstract
[en] We present the HERMES preliminary data of virtual photon absorption cross section difference [σ1/2 - σ3/2] for the proton and neutron in deep inelastic scattering of 27.6 GeV longitudinally polarized positrons from polarized 1H and 3He internal gas targets. The data were collected in the region above the nucleon resonances. The DIS contribution to the generalized Gerasimov-Drell-Hearn (GDH) integral for the nucleons is shown. Refs. 7 (author)
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Joint ECT*/JLAB Workshop; Trento (Italy); 18-29 May 1998; Title of the Supplementum: N* Physics and Nonperturbative Quantum Chromodynamics
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Journal Article
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Conference; Numerical Data
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Few-Body Systems. Supplementum; ISSN 0177-8811; ; v. 11; p. 193-196
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ABSORPTION, ANTILEPTONS, ANTIMATTER, ANTIPARTICLES, BARYONS, BOSONS, DATA, ELEMENTARY PARTICLES, ENERGY RANGE, EQUATIONS, FERMIONS, GEV RANGE, HADRONS, INELASTIC SCATTERING, INFORMATION, INTERACTIONS, LEPTON-BARYON INTERACTIONS, LEPTON-HADRON INTERACTIONS, LEPTON-NUCLEON INTERACTIONS, LEPTONS, MASSLESS PARTICLES, MATTER, NUCLEONS, NUMERICAL DATA, PARTICLE INTERACTIONS, SCATTERING, SORPTION, TARGETS
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