Precision Physics in Finite and Infinite Volume

点击翻译按钮获取中文摘要

The Standard Model (SM) of particle physics has had great success in its many predictions, but in certain cases there appears to betension with experimental measurements. These discrepancies could be hints of physics hitherto unknown, so it is of greatimportance to discover all flaws in the model. In this two-year project I will do timely and ambitious low-energy SM calculationsneeded for precision tests that in the future can guide in the search for a new model.This project is divided in two areas. The first focusses on flavour physics where quark interactions lead tocharge-parity violation, a phenomenon connected to the matter-antimatter asymmetry of the Universe. I willhere study kaon decays in a finite-volume spacetime, including electromagnetic corrections. The major focus point will be how toanalytically convert finite-volume lattice results for these kaon decays to physical predictions. A key intermediate step will be theunderstanding of pion-pion scattering including electromagnetic corrections, which on its own also is of interest for extraction ofscattering parameters from the lattice.The second focus area concerns the muon magnetic moment for which a possible discrepancy with experiments has beendiscovered. The main focus here will be on analytical calculations to reduce the error on the SM prediction. In one sub-project we willderive the leading structure-dependent finite-volume effects for the hadronic vacuum polarisation allowing for future improvedprecision tests from lattice QCD+QED of the quantity in question. In the other sub-project we will derive short-distance constraints onthe electroweak contribution to the muon magnetic moment with the help of the operator product expansion. These short-distanceconstraints will reduce the current uncertainty on the electroweak contribution.