arXiv subjects

Xiupeng Xie

Publications and source records attributed to Xiupeng Xie.

6 recordsLinked to original sources

arXiv2026

T-odd transverse momentum dependent gluon distributions for tensor polarized deuteron in a spectator model

We present a model calculation of the T-odd transverse momentum dependent distribution functions (TMDs) for gluons inside a tensor polarized deuteron. The model is built on the assumption that an on-shell deuteron can emit a time-like off-shell gluon, with the residual system treated as a single on-shell spectator particle. The spectator mass is described via a spectral function, which allows it to take real values over a continuous range. The final-state interaction required to generate nonvanishing T-odd functions are implemented via single-gluon exchange between the spectator and the outgoing parton. We derive analytical expressions for six T-odd gluon TMDs, and present numerical results characterizing their dependence on the longitudinal momentum fraction $x$ and the transverse momentum $\bm{k}_T$.

hep-ph↗

arXiv2026

Twist-3 transverse momentum dependent gluon distributions in a spectator model

We study the twist-3 transverse momentum dependent distributions of gluons in a nucleon within a spectator model framework. In this model, the nucleon is described as emitting a virtual (time-like) gluon and an on-shell spectator particle, with the spectator mass treated continuously via a spectral function. The twist-3 gluon-gluon correlators, $Φ^{+i;+-}$ and $Φ^{ij;l+}$, are parameterized by a set of complex functions, whose real and imaginary parts correspond to T-even and T-odd components, respectively. We numerically check the equation of motion relation for these distributions and find that relation holds fairly well in the spectator model.

hep-ph↗

arXiv2026

Gluon TMDs for tensor polarized deuteron in a spectator model

We present a model calculation of the transverse-momentum-dependent distributions (TMDs) for gluons in a tensor-polarized deuteron. Our model is based on the assumption that an on-shell deuteron can emit a time-like off-shell gluon, while the remaining system is treated as a single on-shell spectator particle whose mass can take on a continuous range of real values, described by a spectral function. For spin-1 hadrons, the polarization is characterized not only by a spin vector $S$ but also by a symmetric traceless spin tensor $T$. The deuteron-gluon-spectator coupling is described by an effective vertex containing three form factors. We obtain analytical expressions for thirteen T-even gluon TMDs. We also provide numerical results for the $x$-dependence and $\bm{k}_T$-dependence of these TMDs. Our analysis reveals non-negligible results of these gluon TMDs, especially for tensor-polarized hadrons, which could potentially be explored in future experimental measurements.

hep-ph↗

arXiv2025

Leading-twist gluon transverse momentum dependent distributions from large-momentum effective theory

We present the perturbative calculation of the leading-twist gluon transverse momentum dependent distribution functions (TMDPDFs) at one-loop level within large-momentum effective theory. By employing the basis of circular polarizations, we generalize the gluon-gluon correlator to a matrix $Φ_{ΛΛ^\prime}^{ij}(x,\bm{k}_T^2;S)$ in the gluon $\otimes$ hadron spin space. Incorporating the transverse momentum of external states, we derive the leading-twist gluon TMDPDFs and quasi-TMDPDFs at one-loop level. Our calculations reveal nonzero distributions for the gluon TMDPDFs $f_{1T}^{\perp g}(x,\bm{k}_T^2)$, $h_{1}^{\perp g}(x,\bm{k}_T^2)$, $h_{1T}^{g}(x,\bm{k}_T^2)$, and $h_{1T}^{\perp g}(x,\bm{k}_T^2)$. These findings enable future lattice QCD simulations to extract these gluon TMDPDFs, which will facilitate a complete determination of nucleon tomography.

hep-ph↗

arXiv2024

T-odd transverse momentum dependent gluon fragmentation functions in a spectator model

We present a model calculation of the T-odd transverse momentum dependent (TMD) gluon fragmentation functions for a spin-1/2 hadron. Our model is based on the postulation that a time-like off-shell gluon can fragment into a hadron and a single spectator particle, which is considered to be on-shell. We consider the effect of the gluon exchange to calculate all necessary one-loop diagrams for the gluon-gluon correlation functions. Two out of four one-loop diagrams give sizeable contributions to the fragmentation functions. We obtain analytical expressions for the four T-odd TMD fragmentation functions of the gluon. We also provide numerical results on the z-dependence and $k_T$-dependence of the fragmentation functions.

hep-ph↗

arXiv2022

T-even transverse momentum dependent gluon fragmentation functions in a spectator model

We present a model calculation of transverse momentum dependent (TMD) gluon fragmentation functions for the spin-1/2 and spin-0 hadrons. The model is based on the assumption that a time-like off-shell gluon can fragments into a hadron and a single spectator particle. So far such spectator models have only been used to calculate the TMD distribution functions of quark and gluons. The gluon-hadron-spectator coupling is described by an effective vertex containing two form factors. We obtain the analytic expressions for the four T-even TMD fragmentation functions of the gluon. We also present the numerical results for the $z$-dependence and $k_T$-dependence of the fragmentation functions. Our study shows that the effects of these fragmentation functions may be significant and could be probed by future experimental measurements.

hep-ph↗