Lattice investigations of the chimera baryon spectrum in the Sp(4) gauge theory

Ed Bennett¹, Deog Ki Hong², Ho Hsiao^3*, Jong-Wan Lee^4,5, C.-J. David Lin^3,6,7, Biagio Lucini^8,1, Maurizio Piai⁹, Davide Vadacchino¹⁰

¹Swansea Academy of Advanced Computing,, Swansea University, Swansea, UK
²Department of Physics, Pusan National University, Busan, Korea
³Institute of Physics, National Yang Ming Chiao Tung University, Hsinchu, Taiwan
⁴Center for Theoretical Physics of the Universe, Institute for Basic Science, Daejeon, Korea
⁵Extreme Physics Institute, Pusan National University, Busan, Korea
⁶Center for High Energy Physics, Chung-Yuan Christian University, Chung-Li, Taiwan
⁷Centre for Theoretical and Computational Physics, National Yang Ming Chiao Tung University, Hsinchu, Taiwan
⁸Department of Mathematics, Swansea University, Swansea, UK
⁹Department of Physics, Swansea University, Swansea, UK
¹⁰Centre for Mathematical Sciences, University of Plymouth, Plymouth, UK

* Presenter:Ho Hsiao, email:thepaulxiao@gmail.com

We study the Sp(4) gauge theory coupled to hyperquark matter fields. This theory potentially serve as an ultraviolet completion of the Standard model in the framework of composite Higgs models that utilise partial compositeness to generate the top-quark mass. We focus on the spectroscopy of chimera baryons, which are composite states composed of two fundamental and one antisymmetric hyperquarks. The chimera baryons having the same quantum number as the top quark are the top partners, which effectively lift the mass of the top quark by mixing with it. Specifically, we investigate, in the quenched approximation, the three lowest-lying parity-even states: Λ_CB, Σ_CB (both with spin 1/2), and Σ*_CB (spin 3/2). The spin-1/2 states are considered as top partner candidates. We extrapolate our results to the continuum and massless limits by applying an effective treatment inspired by Wilson chiral perturbation theory. This study sets the stage for our ongoing lattice simulations with the dynamical hyperquarks.

Keywords: Lattice gauge theory, Beyond Standard Model, Composite Higgs model