Valence quark structure of rho meson using light-front quark model
- Authors
- S. Puhan, S. Sharma, N. Kumar, and H. Dahiya
- Published
- Accepted in PRD
- Date
- 01 November, 2025
- Citations
- 6 (INSPIRE-HEP)
A comprehensive partonic portrait of the rho meson in light-front quark model, featuring all nine leading-twist TMDs — including tensor polarizations unique to spin-1.
The question
We investigate the partonic structure of the rho meson, the lightest spin-1 vector meson, within the light-front quark model (LFQM). To explore the sensitivity to model assumptions, we employ two distinct types of spin wave functions in the LFQM. Using light-front helicity wave functions, we derive explicit expressions for the leading-twist and subleading-twist quark parton distribution functions (PDFs), and evolve the leading-twist PDFs to higher scales with next-to-leading order (NLO) Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution. We have also calculated the Mellin moment from the evolved PDFs using a simple neural network frame and compared with available theoretical predictions. Furthermore, we compute the full set of nine leading-twist transverse-momentum-dependent distributions (TMDs) for the valence quark in the rho meson, including three tensor TMDs that arise from spin-1 tensor polarization of the hadron. Positivity constraints for the PDFs and TMDs are examined within this framework. Our findings highlight the crucial role of tensor polarization in shaping the three-dimensional partonic structure of vector mesons.
What we found
Comprehensive study of rho meson partonic structure using two distinct spin wave functions in LFQM. Computes all nine leading-twist TMDs including three tensor TMDs unique to spin-1, and evolves PDFs via NLO DGLAP.
Authors: S. Puhan, S. Sharma, N. Kumar, and H. Dahiya
Published in: Accepted in PRD