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Title: Longitudinal-Transverse Separations of Deep-Inelastic Structure Functions at Low Q{sup 2} for Hydrogen and Deuterium

Abstract

We report on a study of the longitudinal to transverse cross section ratio, R={sigma}{sub L}/{sigma}{sub T}, at low values of x and Q{sup 2}, as determined from inclusive inelastic electron-hydrogen and electron-deuterium scattering data from Jefferson Laboratory Hall C spanning the four-momentum transfer range 0.06<Q{sup 2}<2.8 GeV{sup 2}. Even at the lowest values of Q{sup 2}, R remains nearly constant and does not disappear with decreasing Q{sup 2}, as might be expected. We find a nearly identical behavior for hydrogen and deuterium.

Authors:
;  [1];  [2]; ; ; ; ; ; ; ;  [3]; ; ;  [4]; ; ; ;  [5]; ; more »;  [6] « less
  1. Vrije Universiteit, 1081 HV Amsterdam (Netherlands)
  2. (NIKHEF), 1009 DB Amsterdam (Netherlands)
  3. Hampton University, Hampton, Virginia 23668 (United States)
  4. Argonne National Laboratory, Argonne, Illinois 60439 (United States)
  5. Yerevan Physics Institute, 375036, Yerevan (Armenia)
  6. Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States) (and others)
Publication Date:
OSTI Identifier:
20951205
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review Letters; Journal Volume: 98; Journal Issue: 14; Other Information: DOI: 10.1103/PhysRevLett.98.142301; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; CEBAF ACCELERATOR; CROSS SECTIONS; DEEP INELASTIC SCATTERING; DEUTERIUM; ELECTRON BEAMS; FOUR MOMENTUM TRANSFER; HYDROGEN; STRUCTURE FUNCTIONS

Citation Formats

Tvaskis, V., Blok, H. P., National Instituut voor Kernfysica en Hoge-Energiefysica, Christy, M. E., Baker, O. K., Cochran, A., Cole, L., Gasparian, A., Nazaryan, V., Sato, Y., Uzzle, A., Arrington, J., Jackson, H. E., Potterveld, D. H., Asaturyan, R., Mkrtchyan, H., Stepanyan, S., Tadevosian, V., Bosted, P., Ent, R., and Fenker, H. C.. Longitudinal-Transverse Separations of Deep-Inelastic Structure Functions at Low Q{sup 2} for Hydrogen and Deuterium. United States: N. p., 2007. Web. doi:10.1103/PHYSREVLETT.98.142301.
Tvaskis, V., Blok, H. P., National Instituut voor Kernfysica en Hoge-Energiefysica, Christy, M. E., Baker, O. K., Cochran, A., Cole, L., Gasparian, A., Nazaryan, V., Sato, Y., Uzzle, A., Arrington, J., Jackson, H. E., Potterveld, D. H., Asaturyan, R., Mkrtchyan, H., Stepanyan, S., Tadevosian, V., Bosted, P., Ent, R., & Fenker, H. C.. Longitudinal-Transverse Separations of Deep-Inelastic Structure Functions at Low Q{sup 2} for Hydrogen and Deuterium. United States. doi:10.1103/PHYSREVLETT.98.142301.
Tvaskis, V., Blok, H. P., National Instituut voor Kernfysica en Hoge-Energiefysica, Christy, M. E., Baker, O. K., Cochran, A., Cole, L., Gasparian, A., Nazaryan, V., Sato, Y., Uzzle, A., Arrington, J., Jackson, H. E., Potterveld, D. H., Asaturyan, R., Mkrtchyan, H., Stepanyan, S., Tadevosian, V., Bosted, P., Ent, R., and Fenker, H. C.. Fri . "Longitudinal-Transverse Separations of Deep-Inelastic Structure Functions at Low Q{sup 2} for Hydrogen and Deuterium". United States. doi:10.1103/PHYSREVLETT.98.142301.
@article{osti_20951205,
title = {Longitudinal-Transverse Separations of Deep-Inelastic Structure Functions at Low Q{sup 2} for Hydrogen and Deuterium},
author = {Tvaskis, V. and Blok, H. P. and National Instituut voor Kernfysica en Hoge-Energiefysica and Christy, M. E. and Baker, O. K. and Cochran, A. and Cole, L. and Gasparian, A. and Nazaryan, V. and Sato, Y. and Uzzle, A. and Arrington, J. and Jackson, H. E. and Potterveld, D. H. and Asaturyan, R. and Mkrtchyan, H. and Stepanyan, S. and Tadevosian, V. and Bosted, P. and Ent, R. and Fenker, H. C.},
abstractNote = {We report on a study of the longitudinal to transverse cross section ratio, R={sigma}{sub L}/{sigma}{sub T}, at low values of x and Q{sup 2}, as determined from inclusive inelastic electron-hydrogen and electron-deuterium scattering data from Jefferson Laboratory Hall C spanning the four-momentum transfer range 0.06<Q{sup 2}<2.8 GeV{sup 2}. Even at the lowest values of Q{sup 2}, R remains nearly constant and does not disappear with decreasing Q{sup 2}, as might be expected. We find a nearly identical behavior for hydrogen and deuterium.},
doi = {10.1103/PHYSREVLETT.98.142301},
journal = {Physical Review Letters},
number = 14,
volume = 98,
place = {United States},
year = {Fri Apr 06 00:00:00 EDT 2007},
month = {Fri Apr 06 00:00:00 EDT 2007}
}
  • We report on a study of the longitudinal to transverse cross section ratio, R={sigma}{sub L} {sigma}{sub T}, at low values of x and Q{sup 2}, as determined from inclusive inelastic electron-hydrogen and electron-deuterium scattering data from Jefferson Lab Hall C spanning the four-momentum transfer range 0.06 < Q{sup 2} < 2.8 GeV{sup 2}. Even at the lowest values of Q{sup 2}, R remains nearly constant and does not disappear with decreasing Q{sup 2}, as expected. We find a nearly identical behavior for hydrogen and deuterium.
  • We report on a study of the longitudinal to transverse cross section ratio, R={sigma}{sub L}/{sigma}{sub T}, at low values of x and Q{sup 2}, as determined from inclusive inelastic electron-hydrogen and electron-deuterium scattering data from Jefferson Laboratory Hall C spanning the four-momentum transfer range 0.06<Q{sup 2}<2.8 GeV{sup 2}. Even at the lowest values of Q{sup 2}, R remains nearly constant and does not disappear with decreasing Q{sup 2}, as might be expected. We find a nearly identical behavior for hydrogen and deuterium.
  • We report the final results from experiment E140, a recent deep inelastic electron-deuterium and electron-iron scattering experiment at SLAC. In addition, we present the results of a combined global analysis of all SLAC deep inelastic electron-hydrogen and electron-deuterium cross section measurements between 1970 and 1983. Data from seven earlier experiments are re-radiatively corrected and normalized to experiment E140. We report extractions of R(x,Q{sup 2}) and F{sub 2}(x,Q{sup 2}) for hydrogen and deuterium over the entire SLAC kinematic range: .06{le} x {le}.90 and 0.6{le} Q{sup 2} {le}30.0 (GeV{sup 2}). We fine that R{sup p} = R{sup d}, as expected by QCD.more » Extracted values of R(x,Q{sup 2}) are significantly larger than predictions based on QCD and on QCD with the inclusion of kinematic target mass terms. This difference indicates that dynamical higher twist effects may be important in the SLAC kinematic range. A best fit empirical model of R(x,Q{sup 2}) is used to extract F{sub 2} from each cross section measurement. These F{sub 2} extractions are compared with F{sub 2} data from EMC and BCDMS. Agreement is observed with EMC when the EMC data are multiplied by 1.07. Agreement is observed with BCDMS over a limited range in x. The ratios of F{sub 2}{sup d}/F{sub 2}{sup p} are examined for Q{sup 2} dependence. We observe a significant negative slope for x {le} .6, and a significant positive slope above x > .7, in excellent agreement with predictions based on QCD with the inclusion of kinematic target mass terms. 111 refs., 40 figs., 34 tabs.« less
  • The authors propose to measure the inclusive deep inelastic electron-nucleon scattering cross sections on hydrogen and deuterium. Cross sections will be measured in the range of momentum transfers Q{sub min}{sup 2} = 0.160 (GeV/c){sup 2} and Q{sub max}{sup 2} = 160.0 (GeV/c){sup 2}, in the range of recoil hadronic mass squared of W{sub min}{sup 2} = 2 GeV{sup 2} and W{sub max}{sup 2} = 450 GeV{sup 2}. The electromagnetic structure functions, {nu}W{sub 2}(Q{sup 2},{nu}) and W{sub 1}(Q{sup 2},{nu}), of both protons and neutrons will be measured and separated by well-known methods, in the highest possible unexplored FERMILAB kinematical regions. Themore » high intensity Proton-West superconducting beam will be used to yield an electron beam of high purity, based on a synchrotron radiation compensated tuning technique. The electron beam will be used at 150 GeV (5 x 10{sup 8} e{sup {+-}}/pulse), at 175 GeV (3.6 x 10{sup 8} e{sup {+-}}/pulse) and at 250 GeV (1 x 10{sup 8} e{sup {+-}}/pulse). The scattered electron will be detected with good acceptance, good resolution and excellent identification. The detector will be the E-192 apparatus with small additions. A simple self-calibration procedure is available, both in experiment and apparatus, removing beam-associated and target-associated background in the entire (Q{sup 2}, W{sup 2}) kinematical regions. Usually, interesting physics occurs where counting rates are small. This experiment will be completely trust-worthy in such regions because their apparatus provides excellent information on the tracking and identification of scattered electrons.« less
  • We obtain a good analytic fit to the joint Bjorken-x and Q{sup 2} dependences of ZEUS data on the deep-inelastic structure function F{sub 2}{sup p}(x,Q{sup 2}). At fixed virtuality Q{sup 2}, as we showed previously, our expression is an expansion in powers of ln(1/x) that satisfies the Froissart bound. Here we show that for each x, the Q{sup 2} dependence of the data is well described by an expansion in powers of lnQ{sup 2}. The resulting analytic expression allows us to predict the logarithmic derivatives ({partial_derivative}nF{sub 2}{sup p}/({partial_derivative}lnQ{sup 2}){sup n}){sub x} for n = 1,2 and to compare the resultsmore » successfully with other data. We extrapolate the proton structure function F{sub 2}{sup p}(x,Q{sup 2}) to the very large Q{sup 2} and the very small x regions that are inaccessible to present-day experiments and contrast our expectations with those of conventional global fits of parton distribution functions.« less