Original URL: https://www.theregister.com/2012/05/28/bluegene_kaon_decay_calc/

Big Blue supers crunch kaon decay

Massive machines probe matter mystery

By Richard Chirgwin

Posted in HPC, 28th May 2012 00:14 GMT

Looking at the fundamental properties of matter can take some serious computing grunt.

Take the calculation needed to help understand kaon decay – a subatomic particle interaction that helps explain why the universe is made of matter rather than anti-matter: it soaked up 54 million processor hours on Argonne National Laboratory’s BlueGene/P supercomputer near Chicago, along with time on Columbia University’s QCDOC machine, Fermi National Lab’s USQCD (the US Center for Quantum Chromo-Dynamic) Ds cluster, and the UK’s Iridis cluster at the University of Southampton and the DIRAC facility.

The reason so much iron was needed: the kaon decay spans 18 orders of magnitude, which this Physorg article describes as akin to the size difference between “a single bacterium and the size of our entire solar system”. At the smallest scale, the decays measured in the experiment were 1/1000th of a femtometer.

“The actual kaon decay described by the calculation spans distance scales of nearly 18 orders of magnitude, from the shortest distances of one thousandth of a femtometer — far below the size of an atom, within which one type of quark decays into another — to the everyday scale of meters over which the decay is observed in the lab,” Brookhaven explains in its late March release.

Back in 1964, a Nobel-winning Brookhaven experiment observed CP (charge parity) violation, setting up a long-running mystery in physics that remains unsolved.

“The present calculation is a major step forward in a new kind of stringent checking of the Standard Model of particle physics — the theory that describes the fundamental particles of matter and their interactions — and how it relates to the problem of matter/antimatter asymmetry, one of the most profound questions in science today,” said Taku Izubuchi of the RIKEN BNL Research Center and BNL, a member of the research team hat published their findings in Physical Review Letters.

The research is seeking to quantify how much the kaon decay process departs from Standard Model predictions. This “unknown quantity” will then be hunted in calculations in the next generation of IBM supercomputers, BlueGene/Q. ®