LUX likelihood and limits on spin-independent and spin-dependent WIMP couplings with LUXCalc

TL;DR

LUXCalc is a new tool that calculates likelihoods and sets limits on WIMP-nucleon interactions from LUX dark matter data, excluding certain dark matter interpretations of DAMA's signal and constraining effective dark matter theories.

Contribution

The paper introduces LUXCalc, a utility for analyzing LUX data to derive WIMP coupling limits, including novel exclusion of the entire spin-dependent parameter space compatible with DAMA's signal.

Findings

LUX excludes the entire spin-dependent parameter space consistent with DAMA.

Good agreement with published LUX results for spin-independent couplings.

Constraints on effective dark matter models with axial-vector mediators.

Abstract

We present LUXCalc, a new utility for calculating likelihoods and deriving WIMP-nucleon coupling limits from the recent results of the LUX direct search dark matter experiment. After a brief review of WIMP-nucleon scattering, we derive LUX limits on the spin-dependent WIMP-nucleon couplings over a broad range of WIMP masses, under standard assumptions on the relevant astrophysical parameters. We find that, under these and other common assumptions, LUX excludes the entire spin-dependent parameter space consistent with a dark matter interpretation of DAMA's anomalous signal, the first time a single experiment has been able to do so. We also revisit the case of spin-independent couplings, and demonstrate good agreement between our results and the published LUX results. Finally, we derive constraints on the parameters of an effective dark matter theory in which a spin-1 mediator interacts with a fermionic WIMP and Standard Model fermions via axial-vector couplings. A detailed appendix describes the use of LUXCalc with standard codes to place constraints on generic dark matter theories.