The current form of the Standard Model (SM) of particle physics fails to explain the observed matter-antimatter asymmetry in the universe. While the SM partially breaks charge conjugation parity (CP) symmetry, it does not do so to a sufficient extent. In the search for CP-symmetry breaking within the SM, the electric dipole moment (EDM) of the neutron has been extensively studied.
However, the contribution to the neutron EDM (nEDM) from the SM is considerably smaller than the experimental bound, leaving room for potential discovery of new sources of CP-violation. The strong CP-violating $\theta$-term is considered a prime candidate for inducing a non-zero nEDM, along with CP-violating effective operators that describe physics beyond the Standard Model at the hadronic scale.
To accurately determine the contributions to the nEDM from all these sources, precise evaluation of the hadronic matrix elements of the corresponding renormalised operators is essential. In this study, the project proposes a systematic investigation of the effects related to the $\theta$-term in lattice Quantum Chromodynamics (QCD) using an innovative fermion discretisation approach: stabilised Wilson fermions.
University of Aachen, Germany
| Centre national de la recherche scientifique (CNRS), France; Trinity College Dublin, Ireland; Forschungszentrum Julich, Germany; University of Southern Denmark, Denmark; Goethe Universität Frankfurt, Germany; |