Breaking of the Lam-Tung Relation in the Drell-Yan Process at the LHC Shows Tension with the Standard Model Prediction

Strategic Insights -

Research published in the journal Physics Letters B has revealed a long-standing tension between the Lam-Tung relation in the Drell-Yan process at the Large Hadron Collider (LHC) and the Standard Model (SM) prediction. The study, funded by various institutions, including the National Natural Science Foundation of China and the Canadian Anesthesiologists' Society, proposes to cross-check these weak dipole interactions by measuring the violation effects of the Lam-Tung relation at future lepton colliders.

Key Takeaways:

  • The breaking of the Lam-Tung relation in the Drell-Yan process at the LHC exhibits a tension with the Standard Model prediction at O(as3) accuracy.
  • The research proposes to cross-check these weak dipole interactions by measuring the violation effects of the Lam-Tung relation at future lepton colliders through the processes e+e-- Zg- ll¯g and e+e-- Zg- qq¯g.
  • The study aims to disentangle the effects of various dipole operators by considering different decay modes of the Z-boson.
  • The high flavor-tagging efficiencies at lepton colliders could provide strong constraints on the dipole interactions of heavy quarks, such as b and c quarks.
  • The research concludes that the breaking of the Lam-Tung relation could be explained by weak dipole interactions of leptons and quarks, associated with the Z-boson within the framework of the Standard Model Effective Field Theory (SMEFT).

Statistics:

  • The research was funded by the National Natural Science Foundation of China, Institute of High Energy Physics, Chinese Academy of Sciences, Instituto Nazionale di Fisica Nucleare, Canadian Anesthesiologists' Society, and Institute of High Energy Physics, Chinese Academy of Sciences.
  • The research was published in the journal Physics Letters B with the article title "Lam-Tung relation breaking effects and weak dipole moments at lepton colliders" (Volume 870, 2025, p. 139931).
  • The article was accessed via the online journal platform, with the DOI: 10.1016/j.physletb.2025.139931.
  • The research was conducted by Guanghui Li and Xu Li from the Institute of High Energy Physics, Chinese Academy of Sciences, and Bin Yan from an unspecified institution.

Sources:

  • Lam-Tung relation breaking effects and weak dipole moments at lepton colliders. Physics Letters B, 2025, 870():139931.
  • Institute of High Energy Physics, Chinese Academy of Sciences
  • National Natural Science Foundation of China
  • Instituto Nazionale di Fisica Nucleare
  • Canadian Anesthesiologists' Society
  • Physics Letters B - http://www.journals.elsevier.com/physics-letters-b/
  • Guanghui Li, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, People's Republic of China