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Title: Dark matter, light mediators, and the neutrino floor

Authors:
; ; ;
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1349963
Grant/Contract Number:
FG02-13ER42020; SC0010813
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Physical Review D
Additional Journal Information:
Journal Volume: 95; Journal Issue: 5; Related Information: CHORUS Timestamp: 2017-04-06 11:12:48; Journal ID: ISSN 2470-0010
Publisher:
American Physical Society
Country of Publication:
United States
Language:
English

Citation Formats

Dent, James B., Dutta, Bhaskar, Newstead, Jayden L., and Strigari, Louis E. Dark matter, light mediators, and the neutrino floor. United States: N. p., 2017. Web. doi:10.1103/PhysRevD.95.051701.
Dent, James B., Dutta, Bhaskar, Newstead, Jayden L., & Strigari, Louis E. Dark matter, light mediators, and the neutrino floor. United States. doi:10.1103/PhysRevD.95.051701.
Dent, James B., Dutta, Bhaskar, Newstead, Jayden L., and Strigari, Louis E. Tue . "Dark matter, light mediators, and the neutrino floor". United States. doi:10.1103/PhysRevD.95.051701.
@article{osti_1349963,
title = {Dark matter, light mediators, and the neutrino floor},
author = {Dent, James B. and Dutta, Bhaskar and Newstead, Jayden L. and Strigari, Louis E.},
abstractNote = {},
doi = {10.1103/PhysRevD.95.051701},
journal = {Physical Review D},
number = 5,
volume = 95,
place = {United States},
year = {Tue Mar 21 00:00:00 EDT 2017},
month = {Tue Mar 21 00:00:00 EDT 2017}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1103/PhysRevD.95.051701

Citation Metrics:
Cited by: 3works
Citation information provided by
Web of Science

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  • We calculate the neutrino signal resulting from annihilation of secluded dark matter in the Sun. In this class of models, dark matter annihilates first into metastable mediators, which subsequently decay into Standard Model particles. If the mediators are long lived, they will propagate out from the dense solar core before decaying. High energy neutrinos undergo absorption in the Sun. In the standard scenario in which neutrinos are produced directly in the centre of the Sun, absorption is relevant for E∼>100 GeV, resulting in a significant suppression of the neutrino spectrum beyond E ∼ 1 TeV. In the secluded dark mattermore » scenario, the neutrino signal is greatly enhanced because neutrinos are injected away from the core, at lower density. Since the solar density falls exponentially with radius, metastable mediators have a significant effect on the neutrino flux, even for decay lengths which are small compared to the solar radius. Moreover, since neutrino detection cross sections grow with energy, this enhancement of the high energy region of the neutrino spectrum would have a large effect on overall event rates.« less
  • In an extended effective operator framework, we investigate in detail the effects of light mediators on the event spectra of dark matter (DM)-nucleus scatterings. The presence of light mediators changes the interpretation of the current experimental data, especially the determination of DM particle mass. We show by analytic and numerical illustrations that in general for all the operators relevant to spin-independent scatterings, the DM particle mass allowed by a given set of experimental data increases significantly when the mediator particle becomes lighter. For instance, in the case of CDMS-II-Si experiment, the allowed DM particle mass can reach ∼50 (100) GeV atmore » 68% (90%) confidence level, which is much larger than ∼10 GeV in the case with contact interactions. The increase of DM particle mass saturates when the mediator mass is below O(10) MeV. The upper limits from other experiments such as SuperCDMS, CDMSlite, CDEX, XENON10/100, LUX, PandaX etc. all tend to be weaker toward high DM mass regions. In a combined analysis, we show that the presence of light mediators can partially relax the tension in the current results of CDMS-II-Si, SuperCDMS and LUX.« less
  • In an extended effective operator framework, we investigate in detail the effects of light mediators on the event spectra of dark matter (DM)-nucleus scatterings. The presence of light mediators changes the interpretation of the current experimental data, especially the determination of DM particle mass. We show by analytic and numerical illustrations that in general for all the operators relevant to spin-independent scatterings, the DM particle mass allowed by a given set of experimental data increases significantly when the mediator particle becomes lighter. For instance, in the case of CDMS-II-Si experiment, the allowed DM particle mass can reach ∼ 50 (100)  GeV atmore » 68% (90%) confidence level, which is much larger than 0∼ 1 GeV in the case with contact interactions. The increase of DM particle mass saturates when the mediator mass is below O(10) MeV . The upper limits from other experiments such as SuperCDMS, CDMSlite, CDEX, XENON10/100, LUX, PandaX etc. all tend to be weaker toward high DM mass regions. In a combined analysis, we show that the presence of light mediators can partially relax the tension in the current results of CDMS-II-Si, SuperCDMS and LUX.« less
  • Future multi-tonne Direct Detection experiments will be sensitive to solar neutrino induced nuclear recoils which form an irreducible background to light Dark Matter searches. Indeed for masses around 6 GeV the spectra of neutrinos and Dark Matter are so similar that experiments are said to run into a neutrino floor, for which sensitivity increases only marginally with exposure past a certain cross section. In this work we show that this floor can be overcome using the different annual modulation expected from solar neutrinos and Dark Matter. Specifically for cross sections below the neutrino floor the DM signal is observable throughmore » a phase shift and a smaller amplitude for the time-dependent event rate. This allows the exclusion power to be improved by up to an order of magnitude for large exposures. In addition we demonstrate that, using only spectral information, the neutrino floor exists over a wider mass range than has been previously shown, since the large uncertainties in the Dark Matter velocity distribution make the signal spectrum harder to distinguish from the neutrino background. However for most velocity distributions it can still be surpassed using timing information, and so the neutrino floor is not an absolute limit on the sensitivity of Direct Detection experiments.« less
  • Future multi-tonne Direct Detection experiments will be sensitive to solar neutrino induced nuclear recoils which form an irreducible background to light Dark Matter searches. Indeed for masses around 6 GeV the spectra of neutrinos and Dark Matter are so similar that experiments are said to run into a neutrino floor, for which sensitivity increases only marginally with exposure past a certain cross section. In this work we show that this floor can be overcome using the different annual modulation expected from solar neutrinos and Dark Matter. Specifically for cross sections below the neutrino floor the DM signal is observable throughmore » a phase shift and a smaller amplitude for the time-dependent event rate. This allows the exclusion power to be improved by up to an order of magnitude for large exposures. In addition we demonstrate that, using only spectral information, the neutrino floor exists over a wider mass range than has been previously shown, since the large uncertainties in the Dark Matter velocity distribution make the signal spectrum harder to distinguish from the neutrino background. However for most velocity distributions it can still be surpassed using timing information, and so the neutrino floor is not an absolute limit on the sensitivity of Direct Detection experiments.« less