Godzone particle hunters
New Zealand physicists have joined the world-wide search for dark matter, an invisible building block of the Universe.
A group of New Zealand physicists can better collaborate on CERN Large Hadron Collider (LHC) projects based in Switzerland and France thanks to the REANNZ network. The high-speed connection to the Worldwide LHC Computing Grid means New Zealand researchers can partner with CERN members from approximately 60 other counties in the search for new particles.
“REANNZ enables us to import and store data from the CMS experiments and to carry out analyses with this data within hours of it being recorded in Geneva,” says Dr David Krofcheck, a nuclear physicist and senior lecturer at the University of Auckland.
Finding out about matter
The Compact Muon Solenoid (CMS) is a particle physics detector built on the LHC, it detects a wide range of particles and phenomena produced in high-energy proton-proton and heavy ion collisions. Approximately 3,600 people from 183 scientific institutes, representing 38 countries form the CMS collaboration that built and now operate the detector. It is located in an underground cavern at Cessy in France, just across the border from Geneva. As well as hunting for new particles, such as the elusive Higgs boson, the CMS also measures the properties of previously discovered particles with unprecedented precision.
The CMS group hopes to learn more about the origin of mass, extra dimensions of space, the reasons for the imbalance of matter and antimatter observed in the Universe, and dark matter.
“These are each important unanswered problems in particle and nuclear physics. We are hoping the LHC-based experiments will answer our questions about the fundamental properties of matter. Our connection through REANNZ means we can participate at the cutting edge of our field without having to leave the country,” says Dr Krofcheck.
Hunting the Higgs boson
Dr Krofcheck says a principal concern is the lack of any direct evidence for the Higgs boson, a theoretical particle which provides an explanation for the very different masses of elementary particles. It is a mystery how these particles gain mass. To explain how these fundamental particles might gain mass, theories predict a new particle (or set of particles), the Higgs boson particle.
“If this particle exists, the CMS experiments could discover it and study its properties. This discovery would provide great insight into the origin of mass.”
The New Zealand CMS group, led by Dr Krofcheck, is directly involved in a number of experiments including the study of collisions between counter-rotating beams of protons, and, after a large amount of proton-proton collision data has been taken, the group will be involved in studies of collisions between counter-rotating beams of heavy nuclei such as lead.
The University of Auckland's specific role has been to develop and perform tests of the Beam Radiation Monitoring detectors, and to develop analysis programmes for proton-proton and heavy ion reactions. Also, a CMS Data Grid computing site has recently been installed at the university campus.