New Parametrization for Generalized Parton Distributions with Non-Zero Skewedness

ORAL

Abstract

We present a physically motivated parameterization for the unpolarized generalized parton distributions of the nucleon, $H(X,\zeta,t$) and $E(X,\zeta,t)$, obtained from Deeply Virtual Compton Scattering (DVCS) experiments, where $X$ is the struck parton's momentum fraction, $\zeta$, skewedness parameter, is the fraction of longitudinal momentum transfer between the incoming (virtual) photon and the outgoing photon, and $t$ is the four-momentum transfer squared. At variance with other physically constrained parametrizations available in the literature [1,2], ours is the first one that applies to both zero and non-zero values of the skewedness parameter, $\zeta$. We define $H$ and $E$ using overlap integrals of the nucleon light-cone wave functions at large values of $X$ [3], and assuming Regge behavior at low $X$. At $\zeta$ = 0 we use the constraints provided by simultaneous fits to experimental data on both the elastic nucleon form factors and the ``forward'' parton distributions from deep inelastic scattering. Our results at $\zeta$ = 0 are of the same quality of the ones obtained in [1,2]. In order to extend our parametrization to $\zeta \neq$ 0, we work out additional constraints from recent lattice calculations of higher moments of generalized parton distributions [4]. [1] M. Diehl, T. Feldmann, R. Jakob and P. Kroll, Eur. Phys. J. C \textbf{39}, 1 (2005) [2] M. Guidal, M. V. Polyakov, A. V. Radyushkin and M. Vanderhaeghen, Phys. Rev. D \textbf{72}, 054013 (2005) [3] S. J. Brodsky, M. Diehl and D. S. Hwang, Nucl. Phys. B \textbf{596}, 99 (2001) [4] G. Schierholz and J. Zanotti, \textit{private communication}.

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Authors

  • J. Deng

    US Naval Observatory, University of Virginia, Thomas Jefferson National Accelerator Facility, College of William and Mary, US Army Research Office, Brimrose Corporation of America, Hampton University, Department of Physics, University of Rajshahi, Rajshahi, Bangladesh, Department of Physics, Old Dominion University, Norfolk, VA 23529, University of North Carolina at Chapel Hill, Department of Physics, Old Dominion University, Norfolk, Virginia, Department of Physics, Korea University, Seoul, Korea, Department of Physics, University of Virginia, Charlottesville, VA, Department of Physics, Old Dominion University, Norfolk, VA, North Carolina State University and WebAssign, Raleigh, NC, North Carolina State University, Raleigh, NC, Broughton High School, Raleigh, NC, University of Wisconsin at Whitewater, Whitewater, WI, University of North Carolina-Chapel Hill Department of Physics, University of West Virginia - Chemistry Dept., ORNL, Old Dominion University, University of West Virginia Department of Chemistry, Clemson University, South Carolina Governor’s School for Science and Mathematics, College of Charleston, Rice University, Korea Research Institute of Standards and Science, Ohio State University, Wright State University, Yale U, JINR, Dubna, Univ. Fed. do Rio de Janeiro, Vanderbilt Univ./JIHIR(ORNL)/Tsinghua Univ., NSCL(MSU), LLNL, LBNL, Vanderbilt Univ./LBNL/JIHIR(ORNL), Vanderbilt Univ., Jagellonian University, University of Bonn, North Carolina A{\&T} State University, North Carolina Central University, Duke University and TUNL

  • J. Deng

    US Naval Observatory, University of Virginia, Thomas Jefferson National Accelerator Facility, College of William and Mary, US Army Research Office, Brimrose Corporation of America, Hampton University, Department of Physics, University of Rajshahi, Rajshahi, Bangladesh, Department of Physics, Old Dominion University, Norfolk, VA 23529, University of North Carolina at Chapel Hill, Department of Physics, Old Dominion University, Norfolk, Virginia, Department of Physics, Korea University, Seoul, Korea, Department of Physics, University of Virginia, Charlottesville, VA, Department of Physics, Old Dominion University, Norfolk, VA, North Carolina State University and WebAssign, Raleigh, NC, North Carolina State University, Raleigh, NC, Broughton High School, Raleigh, NC, University of Wisconsin at Whitewater, Whitewater, WI, University of North Carolina-Chapel Hill Department of Physics, University of West Virginia - Chemistry Dept., ORNL, Old Dominion University, University of West Virginia Department of Chemistry, Clemson University, South Carolina Governor’s School for Science and Mathematics, College of Charleston, Rice University, Korea Research Institute of Standards and Science, Ohio State University, Wright State University, Yale U, JINR, Dubna, Univ. Fed. do Rio de Janeiro, Vanderbilt Univ./JIHIR(ORNL)/Tsinghua Univ., NSCL(MSU), LLNL, LBNL, Vanderbilt Univ./LBNL/JIHIR(ORNL), Vanderbilt Univ., Jagellonian University, University of Bonn, North Carolina A{\&T} State University, North Carolina Central University, Duke University and TUNL

  • J. Deng

    US Naval Observatory, University of Virginia, Thomas Jefferson National Accelerator Facility, College of William and Mary, US Army Research Office, Brimrose Corporation of America, Hampton University, Department of Physics, University of Rajshahi, Rajshahi, Bangladesh, Department of Physics, Old Dominion University, Norfolk, VA 23529, University of North Carolina at Chapel Hill, Department of Physics, Old Dominion University, Norfolk, Virginia, Department of Physics, Korea University, Seoul, Korea, Department of Physics, University of Virginia, Charlottesville, VA, Department of Physics, Old Dominion University, Norfolk, VA, North Carolina State University and WebAssign, Raleigh, NC, North Carolina State University, Raleigh, NC, Broughton High School, Raleigh, NC, University of Wisconsin at Whitewater, Whitewater, WI, University of North Carolina-Chapel Hill Department of Physics, University of West Virginia - Chemistry Dept., ORNL, Old Dominion University, University of West Virginia Department of Chemistry, Clemson University, South Carolina Governor’s School for Science and Mathematics, College of Charleston, Rice University, Korea Research Institute of Standards and Science, Ohio State University, Wright State University, Yale U, JINR, Dubna, Univ. Fed. do Rio de Janeiro, Vanderbilt Univ./JIHIR(ORNL)/Tsinghua Univ., NSCL(MSU), LLNL, LBNL, Vanderbilt Univ./LBNL/JIHIR(ORNL), Vanderbilt Univ., Jagellonian University, University of Bonn, North Carolina A{\&T} State University, North Carolina Central University, Duke University and TUNL

  • J. Deng

    US Naval Observatory, University of Virginia, Thomas Jefferson National Accelerator Facility, College of William and Mary, US Army Research Office, Brimrose Corporation of America, Hampton University, Department of Physics, University of Rajshahi, Rajshahi, Bangladesh, Department of Physics, Old Dominion University, Norfolk, VA 23529, University of North Carolina at Chapel Hill, Department of Physics, Old Dominion University, Norfolk, Virginia, Department of Physics, Korea University, Seoul, Korea, Department of Physics, University of Virginia, Charlottesville, VA, Department of Physics, Old Dominion University, Norfolk, VA, North Carolina State University and WebAssign, Raleigh, NC, North Carolina State University, Raleigh, NC, Broughton High School, Raleigh, NC, University of Wisconsin at Whitewater, Whitewater, WI, University of North Carolina-Chapel Hill Department of Physics, University of West Virginia - Chemistry Dept., ORNL, Old Dominion University, University of West Virginia Department of Chemistry, Clemson University, South Carolina Governor’s School for Science and Mathematics, College of Charleston, Rice University, Korea Research Institute of Standards and Science, Ohio State University, Wright State University, Yale U, JINR, Dubna, Univ. Fed. do Rio de Janeiro, Vanderbilt Univ./JIHIR(ORNL)/Tsinghua Univ., NSCL(MSU), LLNL, LBNL, Vanderbilt Univ./LBNL/JIHIR(ORNL), Vanderbilt Univ., Jagellonian University, University of Bonn, North Carolina A{\&T} State University, North Carolina Central University, Duke University and TUNL