Improved EDELWEISS-III sensitivity for low-mass WIMPs using a profile likelihood approach

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A90072%2F16%3A00344170" target="_blank" >RIV/68407700:90072/16:00344170 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.1140/epjc/s10052-016-4388-y" target="_blank" >https://doi.org/10.1140/epjc/s10052-016-4388-y</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1140/epjc/s10052-016-4388-y" target="_blank" >10.1140/epjc/s10052-016-4388-y</a>

Result language

angličtina

Original language name

Improved EDELWEISS-III sensitivity for low-mass WIMPs using a profile likelihood approach

Original language description

We report on a dark matter search for a Weakly Interacting Massive Particle (WIMP) in the mass range m(chi) is an element of [4, 30] GeV/c(2) with the EDELWEISS-III experiment. A 2D profile likelihood analysis is performed on data from eight selected detectors with the lowest energy thresholds leading to a combined fiducial exposure of 496 kg-days. External backgrounds from gamma- and beta-radiation, recoils from Pb-206 and neutrons as well as detector intrinsic backgrounds were modelled from data outside the region of interest and constrained in the analysis. The basic data selection and most of the background models are the same as those used in a previously published analysis based on boosted decision trees (BDT) [1]. For the likelihood approach applied in the analysis presented here, a larger signal efficiency and a subtraction of the expected background lead to a higher sensitivity, especially for the lowest WIMP masses probed. No statistically significant signal was found and upper limits on the spin-independent WIMP-nucleon scattering cross section can be set with a hypothesis test based on the profile likelihood test statistics. The 90 % C.L. exclusion limit set for WIMPs with m(chi) = 4 GeV/c(2) is 1.6 x 10(-39) cm(2), which is an improvement of a factor of seven with respect to the BDT-based analysis. For WIMP masses above 15 GeV/c(2) the exclusion limits found with both analyses are in good agreement.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10303 - Particles and field physics

Project

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Continuities

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Publication year

2016

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

European Physical Journal C

ISSN

1434-6044

e-ISSN

1434-6052

Volume of the periodical

76

Issue of the periodical within the volume

10

Country of publishing house

DE - GERMANY

Number of pages

10

Pages from-to

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UT code for WoS article

000385249500005

EID of the result in the Scopus database

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