Binary Neutron Star Mergers as the Source of the Highest Energy Cosmic Rays.

We propose that ultrahigh energy cosmic rays (UHECRs) are produced in binary neutron star (BNS) mergers. This scenario can account for the heretofore inexplicable narrow rigidity range of UHECRs because the jets of BNS mergers are generated by a gravitationally driven dynamo and thus are nearly identical due to the narrow range of BNS masses. Observed UHECRs with energies well beyond 100 EeV can be explained as r-process nuclei, without invoking an exotic source class.

Searching for a dark matter particle with anti-protonic atoms.

A wide range of dark matter candidates have been proposed and are actively being searched for in a large number of experiments, both at high (TeV) and low (sub meV) energies. One dark matter candidate, a deeply bound sexaquark, , with mass GeV (having the same quark content as the hypothesized H-dibaryon, but long lived) is particularly difficult to explore experimentally. In this paper, we propose a scheme in which such a state could be produced at rest through the formation of -He antiprotonic atoms and their annihilation into + , identified both through the unique tag of a final state, as well as through full kinematic reconstruction of the final state recoiling against it.

Connection between a possible fifth force and the direct detection of dark matter.

If there were a fifth force in the dark sector and dark matter (DM) particles interacted nongravitationally with ordinary matter, quantum corrections generically would lead to a fifth force in the visible sector. We show how the strong experimental limits on fifth forces in the visible sector produce bounds on the cross section for DM detection and the strength of the fifth force in the dark sector. For a fifth force comparable in strength to gravity, the spin-independent direct detection cross section must typically be less, similar10;{-55} cm;{2}.

Strong CP problem with 10(32) standard model copies.

We show that a recently proposed solution to the hierarchy problem simultaneously solves the strong CP problem, without requiring an axion or any further new physics. Consistency of black hole physics implies a nontrivial relation between the number of particle species and particle masses, so that with approximately 10(32) copies of the standard model, the TeV scale is naturally explained. At the same time, as shown here, this setup predicts a typical expected value of the strong-CP parameter in QCD of theta approximately 10(-9).

Dark matter and the baryon asymmetry of the universe.

We present a mechanism to generate the baryon asymmetry of the Universe which preserves the net baryon number created in the big bang. If dark matter particles carry baryon number Bx, and sigmaxannih View Article and Find Full Text PDF