Experimental Searches for Dark Matter

Abstract

There is now an enormously rich variety of experimental techniques being brought to bear on experimental searches for dark matter, covering a wide range of suggested forms for it. The existence of “dark matter”, in some form or other, is inferred from a number of relatively simple observations and the problem has been known for over half a century. To explain “dark matter” is one of the foremost challenges today — the answer will be of fundamental importance to cosmologists, astrophysicists, particle physicists, and general relativists. In this article, I will give a brief review of the observational evidence (concentrating on areas of current significant activity), followed by anequally brief summary of candidate solutions for the ‘dark matter’. I will then discuss experimental searches, both direct and indirect. Finally, I will offer prospects for the future.

Is the Physics Within the Solar System Really Understood?

“…Dark matter has been introduced in order to "explain" the gravitational field needed for the galactic rotation curves, the gravitational lensing of galaxies, and the formation of structures in our universe [1]. It also appears in the spectral decomposition of the cosmic microwave background radiation [2].…”

Properties of liquid xenon scintillation for dark matter searches

“…Liquid xenon has a high radioactive purity, a high density (2.94 g/cm 3 at b.p. [1]) and it is not chemically or structurally disruptive.…”

“…Weakly interacting massive particles (WIMPs) are candidates for galactic dark matter [3,4]. Elastic scattering of WIMPs by the nuclei of liquid Xe will produce nuclear recoils with energy up to a few tens of keV [5].…”

Modified Newtonian Gravity as an Alternative to the Dark Matter Hypothesis

“…The dark matter (DM) hypothesis, i.e., the existence of a new particle or a family of particles which interact mainly gravitationally and only very weakly with ordinary matter [5][6][7][8][9].…”