Light particles - A window to fundamental physics

In these proceedings we illustrate that light, very weakly interacting particles can arise naturally from physics which is fundamentally connected to very high energy scales. Searching for them therefore may give us interesting new insights into the structure of fundamental physics. Prime examples are the axion, and more general axion-like particles, as well as hidden sector photons and matter charged under them.Comment: 8 pages, 1 figure, contributed to the proceedings of Axions 2010, January 15-17, 2010, Gainesville, Florid

The Physics Case for Axions, WIMPs, WISPs and Other Weird Stuff

We argue that there exists an excellent `physics case' motivating the search for axions, WIMPs, WISPs and other phenomena testable at low energies. This physics case arises from both experimental and observational evidence as well as the desire to test theoretical model building.Comment: 6 pages. Contribution to the ``4th Patras Workshop on Axions, WIMPs and WISPs'', 18-21 June 2008, Hamburg, German

A Family of WISPy Dark Matter Candidates

Dark matter made from non-thermally produced bosons can have very low, possibly sub-eV masses. Axions and hidden photons are prominent examples of such "dark" very weakly interacting light (slim) particles (WISPs). A suitable mechanism for their non-thermal production is the misalignment mechanism. Their dominant interaction with Standard Model (SM) particles is via photons. In this note we want to go beyond these standard examples and discuss a wide range of scalar and pseudo-scalar bosons interacting with SM matter fermions via derivative interactions. Suitably light candidates arise naturally as pseudo-Nambu-Goldstone bosons. In particular we are interested in examples, inspired by familons, whose interactions have a non-trivial flavor structure.Comment: 14 pages, 3 figures. v2 corrected Eq. (3.14

Getting Stuck: Using Monosignatures to Test Highly Ionizing Particles

In this paper we argue that monojet and monophoton searches can be a sensitive test of very highly ionizing particles such as particles with charges $\gtrsim 150e$ and more generally particles that do not reach the outer parts of the detector. 8 TeV monojet data from the CMS experiment excludes such objects with masses in the range $\lesssim 650~{\text{GeV}}$ and charges $\gtrsim 100e$. This nicely complements searches for highly ionizing objects at ALICE, ATLAS, CMS and LHCb. Expected improvements in these channels will extend the sensitivity range to $m\lesssim 750~{\text{GeV}}$. This search strategy can directly be generalized to other particles that strongly interact with the detector material, such as e.g. magnetic monopoles.Comment: 15 pages, 8 figures, version published in PL