The time-of-flight system for CLAS

Smith, E. S.; Carstens, T.; Distelbrink, J.H.J.; Eckhause, M.; Egiyan, H.; Elouadrhiri, L.; Ficenec, J.; Guidal, M.; Hancock, A. D.; Hersman, F. W.; Holtrop, M.; Jenkins, D.; Kim, W.; Loukachine, K.; MacArthur, K.; Marchand, Claude; Mecking, B. A.; Mutchler, G. S.; Schutt, D. W.; Smith, L. C.; Smith, T.; Taylor, S.; Tung, T. Y.; Weisenberger, A.G.; Welsh, Robert E.

doi:10.1016/s0168-9002(99)00484-2

Cited by 141 publications

(75 citation statements)

References 18 publications

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“…Momentum information for charged particles was obtained via tracking through three regions of multiwire drift chambers [17] inside a toroidal magnetic field (∼0.5 T), generated by six superconducting coils. Time-of-flight (TOF) scintillators were used for charged hadron identification [18]. The interaction time between the incoming photon and the target was measured by the start counter [19], consisting of 24 strips of 2.2-mm-thick plastic scintillators surrounding the target cell.…”

Section: Methodsmentioning

confidence: 99%

Cascade production in the reactionsγp→K+K+(X)and
Guo¹,
Weygand²,
Kubarovsky³
et al. 2007
Phys. Rev. C
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Section: Methodsmentioning

confidence: 99%

Cascade production in the reactionsγp→K+K+(X)and
Guo¹,
Weygand²,
Kubarovsky³
et al. 2007
Phys. Rev. C
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“…Electrons were detected in the scattering angle range from 8 • to about 50 • . Three regions of drift chambers (DC) [63] determine charged particle trajectories, followed by Cherenkov counters (CC) [64] and electromagnetic calorimeters (EC) [65] for electron identification, while timing is provided by a scintillation counter (SC) system [66]. For EG1b, the trigger was optimized for inclusive electrons and required a coincidence between signals above threshold in the EC and the CC.…”

Section: The Experimentsmentioning

confidence: 99%

Precise determination of the deuteron spin structure at low to moderateQ2with CLAS and extraction of the neutron contribution

Guler¹,

Fersch²,

Kuhn³

et al. 2015

Phys. Rev. C

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Precise determination of the deuteron spin structure at low to moderate Q^{2} with CLAS and extraction of the neutron contribution We present the final results for the deuteron spin structure functions obtained from the full data set collected with Jefferson Lab's CLAS in 2000-2001. Polarized electrons with energies of 1.6, 2.5, 4.2 and 5.8 GeV were scattered from deuteron ( 15 ND3) targets, dynamically polarized along the beam direction, and detected with CLAS. From the measured double spin asymmetry, the virtual photon absorption asymmetry A d 1 and the polarized structure function g d 1 were extracted over a wide kinematic range (0.05 GeV 2 < Q 2 < 5 GeV 2 and 0.9 GeV < W < 3 GeV). We use an unfolding procedure and a parametrization of the corresponding proton results to extract from these data the polarized structure functions A n 1 and g n 1 of the (bound) neutron, which are so far unknown in the resonance region, W < 2 GeV. We compare our final results, including several moments of the deuteron and neutron spin structure functions, with various theoretical models and expectations as well as parametrizations of the world data. The unprecedented precision and dense kinematic coverage of these data can aid in future extractions of polarized parton distributions, tests of perturbative QCD predictions for the quark polarization at large x, a better understanding of quark-hadron duality, and more precise values for higher-twist matrix elements in the framework of the Operator Product Expansion.

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“…The discrimination between photons and The timing resolution as determined from cosmic-ray tests for all counters. Image Source: [38] neutrons is from the β value from the time of flight measurement. The mass separation of π • and η requires the detection of photons has an energy resolution σ/E ≤ 0.1/ E(GeV ) and a position resolution δr ≈ 2 cm at 1 GeV.…”

Section: Forward Electromagnetic Calorimetermentioning

confidence: 99%

Polarization observables for single and double charged pion photo-production with polarized HD target

Peng

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A complete picture of hadron spectroscopy is important for the understanding of the degrees of freedom inside the hadron in the medium energy region. This study will bridge the gap between the hadron/pion picture in the low-energy region and the quark/gluon picture in the high-energy region. However, while only the low-energy resonances have been well identified, the high-energy excited states are broad and overlapping, so can only be disentangled with Partial Wave Analysis (PWA). The present PWA still has ambiguities due to the lack of experimental data, especially data using a polarized neutron target.The G14 experiment in Hall B of Jefferson Lab was designed and conducted to measure polarization observables from both polarized proton and neutron targets. The reaction channels studied in this dissertation are the single pion (γn → pπ − ) and double pion (γp → pπ + π − , and γn → nπ + π − ) photo-production. The E asymmetry in the single pion channel shows good agreement at lower energy with the prediction from two PWA groups: SAID from George Washington University and Bonn-Gatchina from University of Bonn. At higher energy, there is a big discrepancy between the experimental result and PWA prediction. This result is significant since the "missing resonances" are in this higher energy region. The polarization observables(I , P z , P z ) in the two-pion channel with polarized neutron target are the first results that have been measured, and these three observables(I , P z , P z ) in the two-pion channel with polarized proton target are compared with a previous CLAS experiment (G9a). The results are essential for the study of high-energy excited states since this channel has a bigger cross section than the single pion channel in the high-energy region.i

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The time-of-flight system for CLAS

Cited by 141 publications

References 18 publications

Cascade production in the reactionsγp→K+K+(X)and
Guo¹,
Weygand²,
Kubarovsky³
et al. 2007
Phys. Rev. C
Self Cite

Cascade production in the reactionsγp→K+K+(X)and
Guo¹,
Weygand²,
Kubarovsky³
et al. 2007
Phys. Rev. C
Self Cite

Precise determination of the deuteron spin structure at low to moderateQ2with CLAS and extraction of the neutron contribution

Polarization observables for single and double charged pion photo-production with polarized HD target

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The time-of-flight system for CLAS

Cited by 141 publications

References 18 publications

Cascade production in the reactionsγp→K+K+(X)andGuo1, Weygand2, Kubarovsky3 et al. 2007Phys. Rev. CSelf Cite

Cascade production in the reactionsγp→K+K+(X)andGuo1, Weygand2, Kubarovsky3 et al. 2007Phys. Rev. CSelf Cite

Precise determination of the deuteron spin structure at low to moderateQ2with CLAS and extraction of the neutron contribution

Polarization observables for single and double charged pion photo-production with polarized HD target

Contact Info

Product

Resources

About

Cascade production in the reactionsγp→K+K+(X)and
Guo¹,
Weygand²,
Kubarovsky³
et al. 2007
Phys. Rev. C
Self Cite

Cascade production in the reactionsγp→K+K+(X)and
Guo¹,
Weygand²,
Kubarovsky³
et al. 2007
Phys. Rev. C
Self Cite