Quark matter induced extensive air showers

If the dark matter of our Galaxy is composed of nuggets of quarks or antiquarks in a color superconducting phase there will be a small but nonzero flux of these objects through the Earth's atmosphere. A nugget of quark matter will deposit only a small fraction of its kinetic energy in the atmosphere and is likely to be undetectable. If however the impacting object is composed of antiquarks, the energy deposited can be quite large. In this case nuclear annihilations within the nugget will trigger an extensive air shower the particle content of which is similar to that produced by an ultrahigh energy cosmic ray. This paper gives a qualitative description of the basic properties of such a shower. Several distinctions from an air shower initiated by a single ultrahigh energy nucleus will be described, allowing these events to be distinguished from the cosmic ray background. The subtlety of these features may mean that some fraction of the high energy cosmic ray spectrum may in fact be due to this type of dark matter interaction. The estimated flux of dark matter nuggets and the energy deposited in the atmosphere are such that the Pierre Auger Observatory may prove an ideal facility to place constraints on the flux of heavy quark matter objects. This paper attempts to highlight the best techniques to search for a quark matter signature through an extensive air shower signal.