https://doi.org/10.1140/epjc/s10052-024-13682-w
Regular Article - Theoretical Physics
meson transverse momentum-dependent parton distributions
1
Department of Mathematics and Physics, Nanjing Institute of Technology, 211167, Nanjing, China
2
National Laboratory of Solid State Microstructures, Department of Physics, Nanjing University, 210093, Nanjing, China
Received:
26
September
2024
Accepted:
3
December
2024
Published online:
9
January
2025
In this paper, the light-front wave functions (LFWFs) of the meson are evaluated in the framework of the Nambu–Jona-Lasinio model using the proper time regularization scheme. The transverse momentum-dependent parton distributions (TMDs) of the
meson are derived from the overlap representations of the LFWFs. We investigate the
-weighted moments and the x-dependent average transverse momentum
of
meson TMDs. The
shows the typical transverse momenta of quark TMDs in our model. Our findings indicate that the average transverse momenta of
fall within the range of [0.3, 0.45] GeV, while
are in the region of [0.15, 0.30]
. Our TMDs and parton distribution functions (PDFs) exhibit excellent adherence to positive constraints. The investigation of spin densities within the
meson in transverse momentum space reveals axially symmetric distributions for quarks and targets polarized in either the longitudinal or transverse direction. Conversely, unpolarized symmetric distributions occur when the quark is longitudinally polarized and the target is transversely polarized, while exhibiting dipolar distortions in the opposite scenario. A comparison between TMDs from LFWFs and those from a covariant approach demonstrates that TMDs from LFWFs more effectively satisfy positive constraints than their counterparts from the covariant approach. Furthermore, the x-moments of
meson PDFs indicate that
is larger using LFWFs than with the covariant approach. Additionally, analysis of quark spin densities within the
meson reveals that
yields a negative result using the covariant approach, whereas
derived from LFWFs produces a positive outcome.
© The Author(s) 2025
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
Funded by SCOAP3.