COSINE100 and DAMA/LIBRAphase2 in WIMP effective models
Abstract
Assuming a standard Maxwellian for the WIMP velocity distribution, we obtain the bounds from null WIMP search results of 59.5 days of COSINE100 data on the DAMA/LIBRAphase2 modulation effect within the context of the nonrelativistic effective theory of WIMPnucleus scattering. Here, we systematically assume that one of the effective operators allowed by Galilean invariance dominates in the effective Hamiltonian of a spin1/2 dark matter (DM) particle. We find that, although DAMA/LIBRA and COSINE100 use the same sodiumiodide target, the comparison of the two results still depends on the particlephysics model. This is mainly due to two reasons: i) the WIMP signal spectral shape; ii) the expected modulation fractions, when the upper bound on the timeaveraged rate in COSINE100 is converted into a constraint on the annual modulation component in DAMA/LIBRA . We find that the latter effect is the dominant one. For several effective operators the expected modulation fractions are larger than in the standard spinindependent or spindependent interaction cases. As a consequence, compatibility between the modulation effect observed in DAMA/LIBRA and the null result from COSINE100 is still possible for several nonrelativistic operators. At low WIMP masses such relatively high values of the modulation fractions arise because COSINE100 is mainly sensitive to WIMPsodium scattering events, due to the higher threshold compared to DAMA/LIBRA . A next COSINE analysis is expected to have a full sensitivity for the 5 σ region of DAMA/LIBRA.
 Publication:

Journal of Cosmology and Astroparticle Physics
 Pub Date:
 June 2019
 DOI:
 10.1088/14757516/2019/06/048
 arXiv:
 arXiv:1904.00128
 Bibcode:
 2019JCAP...06..048A
 Keywords:

 High Energy Physics  Phenomenology;
 Astrophysics  Cosmology and Nongalactic Astrophysics;
 Astrophysics  Instrumentation and Methods for Astrophysics;
 High Energy Physics  Experiment
 EPrint:
 22 pages, 6 figures, 5 tables. Updated to published version