Semi-Inclusive Charged-Pion Electroproduction off Protons and Deuterons: Cross Sections, Ratios and Access to the Quark-Parton Model at Low Energies
| Popis souboru: | application/pdf |
|---|---|
| Jazyk: | English |
| Přístupová URL adresa: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::856c95a145128f4ba77387e0e34fa65e http://arxiv.org/abs/1103.1649 |
| Rights: | OPEN |
| Přírůstkové číslo: | edsair.doi.dedup.....856c95a145128f4ba77387e0e34fa65e |
| Autor: | N. Kalantarians, C. Xu, L. Yuan, T. Horn, A. Ahmidouch, Y. Cui, Dipangkar Dutta, P. E. Reimer, G. S. Adams, E. Schulte, W. Hinton, R. J. Holt, T. Navasardyan, R. Ent, S. A. Wood, Curtis Smith, Y. Liang, S. Danagoulian, M. Wang, H. Mkrtchyan, Simon Henry Connell, K. Hafidi, P. Bosted, Y. Li, E. Segbefia, S. E. Rock, A. N. Villano, A. Asaturyan, Bogdan Wojtsekhowski, John Arrington, S. Vidakovic, V. Tadevosyan, Glen A. Warren, C. Bertoncini, M. M. Dalton, James J. Kelly, I. Niculescu, M. E. Christy, O. K. Baker, P. McKee, X. Zheng, T. Angelescu, G. Niculescu, N. Benmouna, D. J. Mack, L. Gan, J. Roche, J. A. Dunne, X. Jiang, D. G. Meekins, A. Mkrtchyan, V. P. Kubarovsky, J. Reinhold, S. Malace, H. Breuer, W. U. Boeglin, Donal Day, E. V. Hungerford, A. K. Opper, E. McGrath, C. E. Keppel, F. R. Wesselmann, Geoffrey Smith, R. Asaturyan, N. El Khayari, Pete Markowitz, V. V. Frolov, G. M. Huber, M. Ungaro, P. Stoler, B. Moziak, H. P. Blok, K. Joo, A. Uzzle, H. C. Fenker, L. G. Tang, T. Ostapenko, W. F. Vulcan, M. K. Jones, D. Gaskell |
| Jazyk: | angličtina |
| Rok vydání: | 2011 |
| Předmět: |
Physics
Quark Nuclear and High Energy Physics Particle physics Proton 010308 nuclear & particles physics Scattering High Energy Physics::Phenomenology Nuclear Theory FOS: Physical sciences Parton Deep inelastic scattering 01 natural sciences Nuclear physics Pion 0103 physical sciences Invariant mass High Energy Physics::Experiment Nuclear Experiment (nucl-ex) 010306 general physics Nucleon Nuclear Experiment |
| Popis: | A large set of cross sections for semi-inclusive electroproduction of charged pions ($��^\pm$) from both proton and deuteron targets was measured. The data are in the deep-inelastic scattering region with invariant mass squared $W^2$ > 4 GeV$^2$ and range in four-momentum transfer squared $2 < Q^2 < 4$ (GeV/c)$^2$, and cover a range in the Bjorken scaling variable 0.2 < x < 0.6. The fractional energy of the pions spans a range 0.3 < z < 1, with small transverse momenta with respect to the virtual-photon direction, $P_t^2 < 0.2$ (GeV/c)$^2$. The invariant mass that goes undetected, $M_x$ or W', is in the nucleon resonance region, W' < 2 GeV. The new data conclusively show the onset of quark-hadron duality in this process, and the relation of this phenomenon to the high-energy factorization ansatz of electron-quark scattering and subsequent quark --> pion production mechanisms. The x, z and $P_t^2$ dependences of several ratios (the ratios of favored-unfavored fragmentation functions, charged pion ratios, deuteron-hydrogen and aluminum-deuteron ratios for $��^+$ and $��^-$) have been studied. The ratios are found to be in good agreement with expectations based upon a high-energy quark-parton model description. We find the azimuthal dependences to be small, as compared to exclusive pion electroproduction, and consistent with theoretical expectations based on tree-level factorization in terms of transverse-momentum-dependent parton distribution and fragmentation functions. In the context of a simple model, the initial transverse momenta of $d$ quarks are found to be slightly smaller than for $u$ quarks, while the transverse momentum width of the favored fragmentation function is about the same as for the unfavored one, and both fragmentation widths are larger than the quark widths. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|