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Title: Analysis of the theoretical bias in dark matter direct detection

Abstract

Fitting the model ''A'' to dark matter direct detection data, when the model that underlies the data is ''B'', introduces a theoretical bias in the fit. We perform a quantitative study of the theoretical bias in dark matter direct detection, with a focus on assumptions regarding the dark matter interactions, and velocity distribution. We address this problem within the effective theory of isoscalar dark matter-nucleon interactions mediated by a heavy spin-1 or spin-0 particle. We analyze 24 benchmark points in the parameter space of the theory, using frequentist and Bayesian statistical methods. First, we simulate the data of future direct detection experiments assuming a momentum/velocity dependent dark matter-nucleon interaction, and an anisotropic dark matter velocity distribution. Then, we fit a constant scattering cross section, and an isotropic Maxwell-Boltzmann velocity distribution to the simulated data, thereby introducing a bias in the analysis. The best fit values of the dark matter particle mass differ from their benchmark values up to 2 standard deviations. The best fit values of the dark matter-nucleon coupling constant differ from their benchmark values up to several standard deviations. We conclude that common assumptions in dark matter direct detection are a source of potentially significant bias.

Authors:
 [1]
  1. Institut für Theoretische Physik, Friedrich-Hund-Platz 1, 37077 Göttingen (Germany)
Publication Date:
OSTI Identifier:
22375855
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2014; Journal Issue: 09; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ANISOTROPY; COUPLING CONSTANTS; CROSS SECTIONS; DETECTION; INTERACTIONS; NONLUMINOUS MATTER; NUCLEONS; SCATTERING; SIMULATION; SPACE

Citation Formats

Catena, Riccardo, E-mail: riccardo.catena@theorie.physik.uni-goettingen.de. Analysis of the theoretical bias in dark matter direct detection. United States: N. p., 2014. Web. doi:10.1088/1475-7516/2014/09/049.
Catena, Riccardo, E-mail: riccardo.catena@theorie.physik.uni-goettingen.de. Analysis of the theoretical bias in dark matter direct detection. United States. doi:10.1088/1475-7516/2014/09/049.
Catena, Riccardo, E-mail: riccardo.catena@theorie.physik.uni-goettingen.de. 2014. "Analysis of the theoretical bias in dark matter direct detection". United States. doi:10.1088/1475-7516/2014/09/049.
@article{osti_22375855,
title = {Analysis of the theoretical bias in dark matter direct detection},
author = {Catena, Riccardo, E-mail: riccardo.catena@theorie.physik.uni-goettingen.de},
abstractNote = {Fitting the model ''A'' to dark matter direct detection data, when the model that underlies the data is ''B'', introduces a theoretical bias in the fit. We perform a quantitative study of the theoretical bias in dark matter direct detection, with a focus on assumptions regarding the dark matter interactions, and velocity distribution. We address this problem within the effective theory of isoscalar dark matter-nucleon interactions mediated by a heavy spin-1 or spin-0 particle. We analyze 24 benchmark points in the parameter space of the theory, using frequentist and Bayesian statistical methods. First, we simulate the data of future direct detection experiments assuming a momentum/velocity dependent dark matter-nucleon interaction, and an anisotropic dark matter velocity distribution. Then, we fit a constant scattering cross section, and an isotropic Maxwell-Boltzmann velocity distribution to the simulated data, thereby introducing a bias in the analysis. The best fit values of the dark matter particle mass differ from their benchmark values up to 2 standard deviations. The best fit values of the dark matter-nucleon coupling constant differ from their benchmark values up to several standard deviations. We conclude that common assumptions in dark matter direct detection are a source of potentially significant bias.},
doi = {10.1088/1475-7516/2014/09/049},
journal = {Journal of Cosmology and Astroparticle Physics},
number = 09,
volume = 2014,
place = {United States},
year = 2014,
month = 9
}