Exclusive $π^+$ electroproduction off the proton from low to high -t

S. Basnet; G. M. Huber; W. B. Li; H. P. Blok; D. Gaskell; T. Horn; K. Aniol; J. Arrington; E. J. Beise; W. Boeglin; E. J. Brash; H. Breuer; C. C. Chang; M. E. Christy; R. Ent; E. Gibson; R. J. Holt; S. Jin; M. K. Jones; C. E. Keppel; W. Kim; P. M. King; V. Kovaltchouk; J. Liu; G. J. Lolos; D. J. Mack; D. J. Margaziotis; P. Markowitz; A. Matsumura; D. Meekins; T. Miyoshi; H. Mkrtchyan; I. Niculescu; Y. Okayasu; L. Pentchev; C. Perdrisat; D. Potterveld; V. Punjabi; P. Reimer; J. Reinhold; J. Roche; A. Sarty; G. R. Smith; V. Tadevosyan; L. G. Tang; V. Tvaskis; J. Volmer; W. Vulcan; G. Warren; S. A. Wood; C. Xu; X. Zheng

doi:10.1103/physrevc.100.065204

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arXiv · 1911.11681

Exclusive $π^+$ electroproduction off the proton from low to high -t

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Abstract

Background: Measurements of exclusive meson production are a useful tool in the study of hadronic structure. In particular, one can discern the relevant degrees of freedom at different distance scales through these studies. Purpose: To study the transition between non-perturbative and perturbative Quantum Chromodyanmics as the square of four momentum transfer to the struck proton, -t, is increased. Method: Cross sections for the $^1$H(e,e'$π^+$)n reaction were measured over the -t range of 0.272 to 2.127 GeV$^2$ with limited azimuthal coverage at fixed beam energy of 4.709 GeV, Q$^2$ of 2.4 GeV$^2$ and W of 2.0 GeV at the Thomas Jefferson National Accelerator Facility (JLab) Hall C. Results: The -t dependence of the measured $π^+$ electroproduction cross section generally agrees with prior data from JLab Halls B and C. The data are consistent with a Regge amplitude based theoretical model, but show poor agreement with a Generalized Parton Distribution (GPD) based model. Conclusion: The agreement of cross sections with prior data implies small contribution from the interference terms, and the confirmation of the change in t-slopes between the low and high -t regions previously observed in photoproduction indicates the changing nature of the electroproduction reaction in our kinematic regime.

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S. Basnet, G. M. Huber, W. B. Li, H. P. Blok, D. Gaskell, T. Horn, K. Aniol, J. Arrington, E. J. Beise, W. Boeglin, E. J. Brash, H. Breuer, C. C. Chang, M. E. Christy, R. Ent, E. Gibson, R. J. Holt, S. Jin, M. K. Jones, C. E. Keppel, W. Kim, P. M. King, V. Kovaltchouk, J. Liu, G. J. Lolos, D. J. Mack, D. J. Margaziotis, P. Markowitz, A. Matsumura, D. Meekins, T. Miyoshi, H. Mkrtchyan, I. Niculescu, Y. Okayasu, L. Pentchev, C. Perdrisat, D. Potterveld, V. Punjabi, P. Reimer, J. Reinhold, J. Roche, A. Sarty, G. R. Smith, V. Tadevosyan, L. G. Tang, V. Tvaskis, J. Volmer, W. Vulcan, G. Warren, S. A. Wood, C. Xu, X. Zheng. 2019-11-26. Exclusive $π^+$ electroproduction off the proton from low to high -t. https://doi.org/10.1103/physrevc.100.065204

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