Academic Commons

Theses Doctoral

Neutral Kaon Mixing from Lattice QCD

Bai, Ziyuan

In this work, we report the lattice calculation of two important quantities which emerge from second order, K0 − ¯ K0 mixing : ∆MK and K. The RBC-UKQCD collaboration has performed the first calculation of ∆MK with unphysical kinematics [1]. We now extend this calculation to near-physical and physical ensembles. In these physical or near-physical calculations, the two-pion energies are below the kaon threshold, and we have to examine the two-pion intermediate states contribution to ∆MK, as well as the enhanced finite volume corrections arising from these two-pion intermediate states. We also report the first lattice calculation of the long-distance contribution to the indirect CP violation parameter, the K. This calculation involves the treatment of a short-distance, ultra-violet divergence that is absent in the calculation of ∆MK, and we will report our techniques for correcting this divergence on the lattice. In this calculation, we used unphysical quark masses on the same ensemble that we used in [1]. Therefore, rather than providing a physical result, this calculation demonstrates the technique for calculating K, and provides an approximate understanding the size of the long-distance contributions. Various new techniques are employed in this work, such as the use of All-Mode-Averaging (AMA), the All-to-All (A2A) propagators and the use of super-jackknife method in analyzing the data.


  • thumnail for Bai_columbia_0054D_14409.pdf Bai_columbia_0054D_14409.pdf application/pdf 3.3 MB Download File

More About This Work

Academic Units
Thesis Advisors
Christ, Norman
Ph.D., Columbia University
Published Here
February 9, 2018
Academic Commons provides global access to research and scholarship produced at Columbia University, Barnard College, Teachers College, Union Theological Seminary and Jewish Theological Seminary. Academic Commons is managed by the Columbia University Libraries.