# Flavor Physics of Up, Down and Strange Quarks from Simulations of Dynamical QCD + QED

**Principal Investigator:** Gerrit Schierholz, DESY, Hamburg (Germany)

**HPC Platform:** JUQUEEN of JSC

One of the most profound open questions in particle physics is to understand the pattern of flavor symmetry breaking and mixing. One has the best theoretical understanding when all three quarks have the same mass, because one can use the full power of SU(3). Starting from the SU(3) symmetric point, the strategy used is to keep the sum of all quark masses fixed at its physical value. That leads to highly constrained, educated fits of any hadron observable. As the up and down quark masses are lowered, a fan structure is seen radiating from the SU(3) symmetric point to the physical point. So far most lattice QCD simulations are performed neglecting electromagnetic effects. In order to compute physical observables to high precision, it is important to include and control contributions from QED. In the project “Flavor Physics of Up, Down and Strange Quarks from Simulations of Dynamical QCD + QED”, an international team of scientists under leadership of particle physicist Prof. Dr. Gerrit Schierholz from DESY (Deutsches Elektronen-Synchrotron) complement their previous simulations by a fully dynamical simulation of QCD + QED, using the vast computing power of the GCS-System JUQUEEN of JSC Jülich.

Prof. Dr. Gerrit Schierholz

DESY, D-22603 Hamburg

e-mail: Gerrit.Schierholz@desy.de