Nuclear modifications on longitudinal-transverse structure-function ratio R in the deuteron
Abstract
In lepton scattering from nuclei, it has been taken for granted that nuclear modifications do not exist for the longitudinal-transverse structure-function ratio R, although nuclear effects in F2 have been investigated for a long time. In fact, experimental data of lepton-nucleus scattering have been analyzed with this assumption. It is obviously not appropriate because nuclear modifications exist in the function R theoretically as shown in this work. In this work, we explain nucleon's Fermi motion's effects by using a convolution description for nuclear structure functions, especially on the deuteron. The longitudinal and transverse structure functions are defined by taking the virtual photon momentum direction along the z axis. However, nucleons in a nucleus could move in any direction, so that nucleon's longitudinal and transverse structure functions could mix with each other in the nuclear medium. Such mixing effects could be of the order of p⃗⊥ 2/Q2, where p⃗⊥ is the nucleon's transverse momentum and Q2 is given by Q2=−q2 with the virtual-photon momentum q, because the transverse Fermi-motion is the source of such a mixture. In addition, nuclear effects are different between the longitudinal and transverse structure functions in the convolution model because their x-dependent functional forms are different. Convolution integrals have different results between the longitudinal and transverse structure functions for nuclei. Because the experiment is in progress at the Thomas Jefferson National Accelerator Facility to measure the function R for the deuteron, the numerical results are shown on the nuclear effects of R in the deuteron. Hopefully, such nuclear effects are found experimentally by future experiments including heavy nuclear targets.
Related
- Phenomenological Estimate for the Longitudinal Unpolarized Structure Function in Semi-inclusive Deep Inelastic Scattering
- Nuclear structure functions and EMC effect in a relativistic deuteron
- Tensor-polarized twist-3 distribution function fLT of spin-1 deuteron
- Unified description of longitudinal and transverse parton dynamics in cold nuclear matter
- Typed Transverse Momentum Parton distribution function computations
BibTeX
@misc{kumano2026nuclear,
title = {{Nuclear modifications on longitudinal-transverse structure-function ratio $R$ in the deuteron}},
author = {S. Kumano},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.17955},
eprint = {2609.17955},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.17955},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Nuclear modifications on longitudinal-transverse structure-function ratio R in the deuteron
AU - S. Kumano
PY - 2026
DA - 2026/09/16
PB - arXiv
DO - 10.48550/arxiv.2609.17955
UR - https://arxiv.org/abs/2609.17955
AB - In lepton scattering from nuclei, it has been taken for granted that nuclear modifications do not exist for the longitudinal-transverse structure-function ratio R, although nuclear effects in F_2 have been investigated for a long time. In fact, experimental data of lepton-nucleus scattering have been analyzed with this assumption. It is obviously not appropriate because nuclear modifications exist in the function R theoretically as shown in this work. In this work, we explain nucleon's Fermi motion's effects by using a convolution description for nuclear structure functions, especially on the deuteron. The longitudinal and transverse structure functions are defined by taking the virtual photon momentum direction along the z axis. However, nucleons in a nucleus could move in any direction, so that nucleon's longitudinal and transverse structure functions could mix with each other in the nuclear medium. Such mixing effects could be of the order of p⃗_⊥^ 2/Q^2, where p⃗_⊥ is the nucleon's transverse momentum and Q^2 is given by Q^2=−q^2 with the virtual-photon momentum q, because the transverse Fermi-motion is the source of such a mixture. In addition, nuclear effects are different between the longitudinal and transverse structure functions in the convolution model because their x-dependent functional forms are different. Convolution integrals have different results between the longitudinal and transverse structure functions for nuclei. Because the experiment is in progress at the Thomas Jefferson National Accelerator Facility to measure the function R for the deuteron, the numerical results are shown on the nuclear effects of R in the deuteron. Hopefully, such nuclear effects are found experimentally by future experiments including heavy nuclear targets.
ER -