LHC constraints on scalar diquarks

• Published in: The journal of high energy physics Vol. 2020; no. 7; pp. 1 - 18
• Main Authors: Pascual-Dias, Bruna, Saha, Pratishruti, London, David
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.07.2020; Springer Nature B.V; SpringerOpen
• Subjects: Beyond Standard Model; Classical and Quantum Gravitation; Constraints; Elementary Particles; Heavy Quark Physics; High energy physics; Physics; Physics and Astronomy; Quantum Field Theories; Quantum Field Theory; Quantum Physics; Regular Article - Theoretical Physics; Relativity Theory; String Theory; Heavy Quark Physics; Beyond Standard Model
• ISSN: 1029-8479; 1029-8479
• DOI: 10.1007/JHEP07(2020)144

A bstract A number of years ago, low-energy constraints on scalar diquarks, particles that couple to two quarks, were examined. It was found that the two most weakly-constrained diquarks are D u and D d , colour antitriplets that couple to u R i u R j and d R i d R j , respectively. These diquarks have not been observed at the LHC. In this paper, we add the LHC measurements to the low-energy analysis, and find that the constraints are significantly improved. As an example, denoting x u as the D u coupling to the first and second generations, for M D u = 600 GeV, the low-energy constraint is | x u | ≤ 14 . 4, while the addition of the LHC dijet measurement leads to | x u | ≤ 0 . 13–0 . 15. Further improvements are obtained by adding the measurement of single top production with a p T cut. These new constraints must be taken into account in making predictions for other low-energy indirect effects of diquarks.