Exclusive Leptonium Electroproduction

@misc{deng2026exclusive,
  title = {{Exclusive Leptonium Electroproduction}},
  author = {Hao-ye Deng and Qi-Ming Feng and Qi-Wei Hu and Si-Qin Huang and Cong-Feng Qiao and Jia-Xuan Shen and Ting-Ting Wang and Shun-Yan Yu and Hao Zhang and Xuan-Heng Zhang and Yi-Nan Zhao},
  howpublished = {arXiv},
  year = {2026},
  month = aug,
  doi = {10.48550/arxiv.2608.30850},
  eprint = {2608.30850},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2608.30850},
}

TY  - UNPB
TI  - Exclusive Leptonium Electroproduction
AU  - Hao-ye Deng
AU  - Qi-Ming Feng
AU  - Qi-Wei Hu
AU  - Si-Qin Huang
AU  - Cong-Feng Qiao
AU  - Jia-Xuan Shen
AU  - Ting-Ting Wang
AU  - Shun-Yan Yu
AU  - Hao Zhang
AU  - Xuan-Heng Zhang
AU  - Yi-Nan Zhao
PY  - 2026
DA  - 2026/08/31
PB  - arXiv
DO  - 10.48550/arxiv.2608.30850
UR  - https://arxiv.org/abs/2608.30850
AB  - Purely leptonic bound states provide precision probes of QED. Positronium (e^+e^-) and muonium (μ^+e^-) have long been observed, whereas dimuonium (μ^+μ^-) and tauonium (τ^+τ^-) remain undiscovered. We study exclusive vector-leptonium electroproduction in ep collisions within nonrelativistic QED. We include the Bethe--Heitler and double deeply virtual Compton scattering contributions and their interference, and calculate the NLO QCD hard-scattering kernels entering the dominant Compton form factor Hcal within collinear GPD factorization. The NLO QCD correction to the DDVCS contribution changes from a strong suppression at low photon virtuality to a sizable enhancement as the lower virtuality cut is raised, with the gluon channel providing the dominant contribution. Bethe--Heitler production dominates the exclusive rate, supporting dedicated dimuonium searches at the EIC and JLab, with larger samples expected at higher-energy electron--proton colliders. The much larger positronium samples provide a high-statistics environment for precision QED studies, whereas tauonium production remains strongly suppressed.
ER  -