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Measurement of R = sigma_L / sigma_T and the Separated Longitudinal and Transverse Structure Functions in the Nucleon Resonance Region

110 Collaboration·Y. Liang·V. Tvaskis·M. E. Christy·A. Ahmidouch·C. S. Armstrong·J. Arrington·R. Asaturyan·S. Avery·O. K. Baker·D. H. Beck·H. P. Blok·C. W. Bochna·W. Boeglin·P. Bosted·M. Bouwhuis·H. Breuer·D. S. Brown·A. Bruell·R. D. Carlini·J. Cha·N. S. Chant·A. Cochran·L. Cole·S. Danagoulian·D. B. Day·J. Dunne·D. Dutta·R. Ent·H. C. Fenker·B. Fox·L. Gan·H. Gao·K. Garrow·D. Gaskell·A. Gasparian·D. F. Geesaman·R. Gilman·P. L. J. Gu`eye·M. Harvey·R. J. Holt·X. Jiang·M. Jones·C. E. Keppel·E. Kinney·W. Lorenzon·A. Lung·D. J. Mack·P. Markowitz·J. W. Martin·K. McIlhany·D. McKee·D. Meekins·M. A. Miller·R. G. Milner·J. H. Mitchell·H. Mkrtchyan·B. A. Mueller·A. Nathan·G. Niculescu·I. Niculescu·T. G. O'Neill·V. Papavassiliou·S. F. Pate·R. B. Piercey·D. Potterveld·R. D. Ransome·J. Reinhold·E. Rollinde·O. Rondon·P. Roos·A. J. Sarty·R. Sawafta·E. C. Schulte·E. Segbefia·C. Smith·S. Stepanyan·S. Strauch·V. Tadevosyan·L. Tang·R. Tieulent·A. Uzzle·W. F. Vulcan·S. A. Wood·F. Xiong·L. Yuan·M. Zeier·B. Zihlmann·V. Ziskin
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Abstract

We report on a detailed study of longitudinal strength in the nucleon resonance region, presenting new results from inclusive electron-proton cross sections measured at Jefferson Lab Hall C in the four-momentum transfer range 0.2 < Q^2 < 5.5 GeV^2. The data have been used to accurately perform 167 Rosenbluth-type longitudinal / transverse separations. The precision R = sigma_L / sigma_T data are presented here, along with the first separate values of the inelastic structure functions F_1 and F_L in this regime. The resonance longitudinal component is found to be significant, both in magnitude and in the existence of defined mass peaks. Additionally, quark-hadron duality is here observed above Q^2 = 1 GeV^2 in the separated structure functions independently.

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110 Collaboration, Y. Liang, V. Tvaskis, M. E. Christy, A. Ahmidouch, C. S. Armstrong, J. Arrington, R. Asaturyan, S. Avery, O. K. Baker, D. H. Beck, H. P. Blok, C. W. Bochna, W. Boeglin, P. Bosted, M. Bouwhuis, H. Breuer, D. S. Brown, A. Bruell, R. D. Carlini, J. Cha, N. S. Chant, A. Cochran, L. Cole, S. Danagoulian, D. B. Day, J. Dunne, D. Dutta, R. Ent, H. C. Fenker, B. Fox, L. Gan, H. Gao, K. Garrow, D. Gaskell, A. Gasparian, D. F. Geesaman, R. Gilman, P. L. J. Gu`eye, M. Harvey, R. J. Holt, X. Jiang, M. Jones, C. E. Keppel, E. Kinney, W. Lorenzon, A. Lung, D. J. Mack, P. Markowitz, J. W. Martin, K. McIlhany, D. McKee, D. Meekins, M. A. Miller, R. G. Milner, J. H. Mitchell, H. Mkrtchyan, B. A. Mueller, A. Nathan, G. Niculescu, I. Niculescu, T. G. O'Neill, V. Papavassiliou, S. F. Pate, R. B. Piercey, D. Potterveld, R. D. Ransome, J. Reinhold, E. Rollinde, O. Rondon, P. Roos, A. J. Sarty, R. Sawafta, E. C. Schulte, E. Segbefia, C. Smith, S. Stepanyan, S. Strauch, V. Tadevosyan, L. Tang, R. Tieulent, A. Uzzle, W. F. Vulcan, S. A. Wood, F. Xiong, L. Yuan, M. Zeier, B. Zihlmann, V. Ziskin. 2013-01-08. Measurement of R = sigma_L / sigma_T and the Separated Longitudinal and Transverse Structure Functions in the Nucleon Resonance Region. https://arxiv.org/abs/nucl-ex/0410027

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