Probing the chromo-electric dipole moment of top quark near the toponium production threshold at LHC
Abstract
The recent observation of an excess near the kinematic tt̅ production threshold by the CMS and ATLAS collaborations suggests the existence of a color-singlet and S-wave quasi-bound state of top quark. Due to the non-relativistic nature of top and anti-top quarks in this threshold region, toponium production provides an ideal system to probe the anomalous dipole moments of the top quark. In this work, we investigate the impact of chromo-electric dipole moment (CEDM) in tt̅-gluon vertex on toponium production at the LHC. We implement the enhanced near-threshold production of the spin-0 color-singlet toponium state ηt via gluon fusion. The resonant toponium contribution is then combined with the continuum tt̅ production amplitude, including the interference effects induced by the top CEDM. Furthermore, we construct a set of asymmetries based on the angular distributions of charged leptons in the leptonic decay channel of tt̅. Finally, we derive the expected exclusion limit on the top quark CEDM parameter dtg using these lepton angular asymmetries.
Related
- Probing the nucleon axial form factor via the e⃗ + + 2H → ν̅e + p + p reaction below the pion-production threshold
- Probing the τ anomalous magnetic and electric dipole moments in photon-induced γγ→τ+τ- production at the FCC-hh
- On recent measurements of toponium threshold enhancement in entire-function-regulated nonlocal quantum field theory
- Toponium Production at Future Muon Colliders and in heavy ion ultraperipheral collisions
- tt̅ spin correlations from toponium production scenarios to non-relativistic resummation beyond the standard perturbative baseline
BibTeX
@misc{ma2026probing,
title = {{Probing the chromo-electric dipole moment of top quark near the toponium production threshold at LHC}},
author = {Kai Ma and Tong Li},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.15493},
eprint = {2610.15493},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.15493},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Probing the chromo-electric dipole moment of top quark near the toponium production threshold at LHC
AU - Kai Ma
AU - Tong Li
PY - 2026
DA - 2026/10/11
PB - arXiv
DO - 10.48550/arxiv.2610.15493
UR - https://arxiv.org/abs/2610.15493
AB - The recent observation of an excess near the kinematic tt̅ production threshold by the CMS and ATLAS collaborations suggests the existence of a color-singlet and S-wave quasi-bound state of top quark. Due to the non-relativistic nature of top and anti-top quarks in this threshold region, toponium production provides an ideal system to probe the anomalous dipole moments of the top quark. In this work, we investigate the impact of chromo-electric dipole moment (CEDM) in tt̅-gluon vertex on toponium production at the LHC. We implement the enhanced near-threshold production of the spin-0 color-singlet toponium state η_t via gluon fusion. The resonant toponium contribution is then combined with the continuum tt̅ production amplitude, including the interference effects induced by the top CEDM. Furthermore, we construct a set of asymmetries based on the angular distributions of charged leptons in the leptonic decay channel of tt̅. Finally, we derive the expected exclusion limit on the top quark CEDM parameter d_t^g using these lepton angular asymmetries.
ER -