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Nader Morshedian

Publications and source records attributed to Nader Morshedian.

4 recordsLinked to original sources

New analysis for Nucleon Form Factors from GPDs

Generalized Parton Distributions (GPDs) provide a comprehensive framework for describing the three-dimensional structure of the nucleon. Extracting GPDs from experimental data requires flexible and physically motivated ansatz. In this study, we introduce a new ansatz, AMA25, designed to address the limitations of the previous model, GSAMA24 (Phys. Rev. C 111 (2025) 2, 025203). We conduct a fast and efficient comparison by fitting AMA25 models and other relevant data using the iMinuit optimization package within a Jupyter Notebook environment. The AMA25 ansatz demonstrates superior fit quality, achieving a reduced $χ^2$, while better satisfying theoretical constraints. Additionally, AMA25 exhibits enhanced stability when extrapolated to the exclusive region. Our analysis highlights the power of modern computational tools for rapid model validation and underscores the importance of innovative ansatz in advancing nucleon structure studies.

hep-ph

Nucleon Form Factors from GPDs

In this study, we introduce a novel ansatz for Generalized Parton Distributions (GPDs), named GSAMA24. This ansatz aims to provide a more accurate and comprehensive description of the internal structure of hadrons by incorporating advanced parameterizations and fitting techniques. We compare the performance of the GSAMA24 ansatz with three established models: the Extended Regge (ER), Modified Gaussian (MG), and M-HS22 ansatz. The GSAMA24 ansatz is designed to address limitations observed in previous models by offering improved flexibility in the ( $t$ )-dependence and skewness parameter $ξ$. Our analysis involves fitting the GSAMA24 ansatz to experimental form factor data and evaluating its predictive power against the ER, MG, and M-HS22 models. The comparison is based on key metrics such as the accuracy of form factor predictions, the consistency with known GPD properties, and the computational efficiency of the fitting process. Results indicate that the GSAMA24 ansatz provides a superior fit to the experimental data, particularly in the high momentum transfer region, where it outperforms the ER and MG models. Additionally, the GSAMA24 ansatz demonstrates better agreement with the theoretical expectations of GPD behavior compared to the M-HS22 model. These findings suggest that the GSAMA24 ansatz is a promising tool for future studies of hadronic structure and could significantly enhance our understanding of the spatial and momentum distributions of quarks and gluons within hadrons.

hep-ph

QCD analysis of $xF_3$ structure functions in deep-inelastic scattering: Mellin transform by Gegenbauer polynomial up to N$^3$LO approximation

This paper provides a thorough examination of the $xF_3$ structure functions in deep-inelastic scattering through a comprehensive QCD analysis. Our approach harnesses sophisticated mathematical techniques, namely the Mellin transform combined with Gegenbauer polynomials. We have employed the Jacobi polynomials approach for analysis, conducting investigations at three levels of precision: Next-to-Leading Order (NLO), Next-to-Next-to-Leading Order (N$^2$LO), and Next-Next-Next-to-Leading Order (N$^3$LO). We have performed a comparison of our sets of valence-quark parton distribution functions with those of recent research groups, specifically CT18 and MSHT20 at NLO and N$^2$LO, and MSTH23 at N$^3$LO, which are concurrent with our current analysis. The combination of Mellin transforms with Gegenbauer polynomials proves to be a powerful tool for investigating the $xF_3$ structure functions in deep-inelastic scattering and the results obtained from our analysis demonstrate a favorable alignment with experimental data.

hep-ph

A new version of fermion coupled coherent states method: Theory and applications in simulation of two-electron systems

We report a new version of fermion coupled coherent states method (FCCS-II) to simulate two-electron systems based on a self-symmetrized six-dimensional (6D) coherent states grid. Unlike the older fermion coupled coherent states method (FCCS-I), FCCS-II does not need any new equations in comparison with the coupled coherent states method. FCCS-II uses a simpler and more efficient approach for symmetrizing the spatial wave function in the simulation of fermionic systems. This method, has significantly increased the speed of computations and give us the capability to simulate the quantum systems with the larger CS grids. We apply FCCS-II to simulate the Helium atom and the Hydrogen molecule based on grids with a large numbers of coherent states. FCCS-II with a relatively low number of CS gives a potential energy curve for H2 that is very close to the exact potential curve. Moreover, we have re-derived all the important equations of the FCCS-I method.

physics.atom-ph