Simultaneous CTEQ-TEA extraction of PDFs and SMEFT parameters from jet and $t\bar{t}$ data

• Published in: The journal of high energy physics Vol. 2023; no. 5
• Main Authors: Gao, Jun, Gao, MeiSen, Hobbs, T. J., Liu, DianYu, Shen, XiaoMin
• Format: Journal Article
• Language: English
• Published: United States Springer Nature 02.05.2023
• Subjects: jets and jet substructure; parton distributions; PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; SMEFT; top quark
• ISSN: 1029-8479; 1029-8479

Recasting phenomenological Lagrangians in terms of SM effective field theory (SMEFT) provides a valuable means of connecting potential BSM physics at momenta well above the electroweak scale to experimental signatures at lower energies. In this work we jointly fit the Wilson coefficients of SMEFT operators as well as the PDFs in an extension of the CT18 global analysis framework, obtaining self-consistent constraints to possible BSM physics effects. Global fits are boosted with machine-learning techniques in the form of neural networks to ensure efficient scans of the full PDF+SMEFT parameter space. We focus on several operators relevant for top-quark pair and jet production at hadron colliders and obtain constraints on the Wilson coefficients with Lagrange Multiplier scans. We find mild correlations between the extracted Wilson coefficients, PDFs, and other QCD parameters, and see indications that these correlations may become more prominent in future analyses based on data of higher precision. This work serves as a new platform for joint analyses of SM and BSM physics based on the CTEQ-TEA framework.