Oxford graduate student's supersymmetry search is LHC physics highlight

26 March 2015

The first ever search for the supersymmetric partner of the charm quark, led by Oxford graduate student Will Kalderon, has been selected by the ATLAS experiment at CERN as one of its physics highlights of the first run of the LHC.

In the first dedicated analysis of its kind, Will has completed an analysis of the ATLAS experiment's data searching for the proposed supersymmetric partner of the charm quark, the so-called “scalar-charm”. His analysis, which excluded low-mass scalar charm quarks, will be published in the next volume of Physical Review Letters.

Working with Alan Barr, Alexandru Dafinca and Claire Gwenlan of the Oxford ATLAS SUSY group, and with collaborators at Yale University, Will proposed and led a search for the proposed supersymmetric partner of the charm quark. The scalar charm is one of the "partner particles" that should exist if supersymmetric particles are responsible for the dark matter in the universe.

The team searched for pair-produced charm quark partners being produced in the high-energy collisions of the LHC. They analysed LHC collisions for decays of the proposed new particle into an (anti-)charm quark together with an invisible dark matter particle of unknown mass. Their results rule out scalar-charms with masses up to about 540 GeV, depending on the mass of the dark matter particle.

Will and the team are now preparing the ATLAS detector for the higher energy second run of the LHC, which will have sensitivity to supersymmetric particles up to much higher masses.

ATLAS event display of an event highlighted by the scalar-charm search analysis