| 1. |
- Aprile, E., et al.
(författare)
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Search for Coherent Elastic Scattering of Solar B-8 Neutrinos in the XENON1T Dark Matter Experiment
- 2021
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 126:9
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Tidskriftsartikel (refereegranskat)abstract
- We report on a search for nuclear recoil signals from solar B-8 neutrinos elastically scattering off xenon nuclei in XENON1T data, lowering the energy threshold from 2.6 to 1.6 keV. We develop a variety of novel techniques to limit the resulting increase in backgrounds near the threshold. No significant B-8 neutrinolike excess is found in an exposure of 0.6 t x y. For the first time, we use the nondetection of solar neutrinos to constrain the light yield from 1-2 keV nuclear recoils in liquid xenon, as well as nonstandard neutrino-quark interactions. Finally, we improve upon world-leading constraints on dark matter-nucleus interactions for dark matter masses between 3 and 11 GeV c(-2) by as much as an order of magnitude.
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| 2. |
- Aprile, E., et al.
(författare)
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Search for inelastic scattering of WIMP dark matter in XENON1T
- 2021
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Ingår i: Physical Review D. - 2470-0010 .- 2470-0029. ; 103:6
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Tidskriftsartikel (refereegranskat)abstract
- We report the results of a search for the inelastic scattering of weakly interacting massive particles (WIMPs) in the XENON1T dark matter experiment. Scattering off Xe-129 is the most sensitive probe of inelastic WIMP interactions, with a signature of a 39.6 keV deexcitation photon detected simultaneously with the nuclear recoil. Using an exposure of 0.83 tonne-years, we find no evidence of inelastic WIMP scattering with a significance of more than 2 sigma. A profile-likelihood ratio analysis is used to set upper limits on the cross section of WIMP-nucleus interactions. We exclude new parameter space for WIMPs heavier than 100 GeV/c(2), with the strongest upper limit of 3.3 x 10(-39) cm(2) for 130 GeV/c(2) WIMPs at 90% confidence level.
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| 3. |
- Aprile, E., et al.
(författare)
-
Energy resolution and linearity of XENON1T in the MeV energy range
- 2020
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Ingår i: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 80:8
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Tidskriftsartikel (refereegranskat)abstract
- Xenon dual-phase time projection chambers designed to search for weakly interacting massive particles have so far shown a relative energy resolutionwhich degrades with energy above similar to 200 keV due to the saturation effects. This has limited their sensitivity in the search for rare events like the neutrinoless double-beta decay of Xe-136 at its Q value, Q(beta beta) similar or equal to 2.46 MeV. For the XENON1T dual-phase time projection chamber, we demonstrate that the relative energy resolution at 1 sigma/mu is as low as (0.80 +/- 0.02)% in its one-ton fiducial mass, and for single-site interactions at Q(beta beta). We also present a new signal correction method to rectify the saturation effects of the signal readout system, resulting in more accurate position reconstruction and indirectly improving the energy resolution. The very good result achieved in XENON1T opens up new windows for the xenon dual-phase dark matter detectors to simultaneously search for other rare events.
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| 4. |
- Aprile, E., et al.
(författare)
-
First Dark Matter Search Results from the XENON1T Experiment
- 2017
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 119:18
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Tidskriftsartikel (refereegranskat)abstract
- We report the first dark matter search results from XENON1T, a similar to 2000-kg-target-mass dual-phase (liquid-gas) xenon time projection chamber in operation at the Laboratori Nazionali del Gran Sasso in Italy and the first ton-scale detector of this kind. The blinded search used 34.2 live days of data acquired between November 2016 and January 2017. Inside the (1042 +/- 12)-kg fiducial mass and in the [5, 40] keV(nr) energy range of interest for weakly interacting massive particle (WIMP) dark matter searches, the electronic recoil background was (1.93 +/- 0.25) x 10(-4) events/(kg x day x keV(ee)), the lowest ever achieved in such a dark matter detector. A profile likelihood analysis shows that the data are consistent with the background-only hypothesis. We derive the most stringent exclusion limits on the spin-independent WIMP-nucleon interaction cross section for WIMP masses above 10 GeV/c(2), with a minimum of 7.7 x 10(-47) cm(2) for 35-GeV/c(2) WIMPs at 90% C.L.
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| 5. |
- Aprile, E., et al.
(författare)
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Physics reach of the XENON1T dark matter experiment
- 2016
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Ingår i: Journal of Cosmology and Astroparticle Physics. - : IOP Publishing. - 1475-7516. ; :4
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Tidskriftsartikel (refereegranskat)abstract
- The XENON1T experiment is currently in the commissioning phase at the Laboratori Nazionali del Gran Sasso, Italy. In this article we study the experiment's expected sensitivity to the spin-independent WIMP-nucleon interaction cross section, based on Monte Carlo predictions of the electronic and nuclear recoil backgrounds. The total electronic recoil background in 1 tonne fiducial volume and (1, 12) keV electronic recoil equivalent energy region, before applying any selection to discriminate between electronic and nuclear recoils, is (1.80+/-0.15) . 10(-4) (kg.day.keV)(-1), mainly due to the decay of Rn-222 daughters inside the xenon target. The nuclear recoil background in the corresponding nuclear recoil equivalent energy region (4, 50) keV, is composed of (0.6 +/- 0.1) (t.y)(-1) from radiogenic neutrons, (1.8+/-0.3) . 10(-2) (t.y)(-1) from coherent scattering of neutrinos, and less than 0.01 (t.y)(-1) from muon-induced neutrons. The sensitivity of XENON1T is calculated with the Pro file Likelihood Ratio method, after converting the deposited energy of electronic and nuclear recoils into the scintillation and ionization signals seen in the detector. We take into account the systematic uncertainties on the photon and electron emission model, and on the estimation of the backgrounds, treated as nuisance parameters. The main contribution comes from the relative scintillation efficiency L-eff, which affects both the signal from WIMPs and the nuclear recoil backgrounds. After a 2 y measurement in 1 tonne fiducial volume, the sensitivity reaches a minimum cross section of 1.6 . 10(-47) cm(2) at m(chi) = 50 GeV/c(2).
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| 6. |
- Aprile, E., et al.
(författare)
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The XENON1T dark matter experiment
- 2017
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Ingår i: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 77:12
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Tidskriftsartikel (refereegranskat)abstract
- The XENON1T experiment at the Laboratori Nazionali del Gran Sasso (LNGS) is the first WIMP dark matter detector operating with a liquid xenon target mass above the ton-scale. Out of its 3.2t liquid xenon inventory, 2.0t constitute the active target of the dual-phase time projection chamber. The scintillation and ionization signals from particle interactions are detected with low-background photomultipliers. This article describes the XENON1T instrument and its subsystems as well as strategies to achieve an unprecedented low background level. First results on the detector response and the performance of the subsystems are also presented.
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| 7. |
- Aprile, E., et al.
(författare)
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Constraining the Spin-Dependent WIMP-Nucleon Cross Sections with XENON1T
- 2019
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 122:14
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Tidskriftsartikel (refereegranskat)abstract
- We report the first experimental results on spin-dependent elastic weakly interacting massive particle (WIMP) nucleon scattering from the XENON1T dark matter search experiment. The analysis uses the full ton year exposure of XENON1T to constrain the spin-dependent proton-only and neutron-only cases. No significant signal excess is observed, and a profile likelihood ratio analysis is used to set exclusion limits on the WIMP-nucleon interactions. This includes the most stringent constraint to date on the WIMP-neutron cross section, with a minimum of 6.3 x 10(-42) cm(2) at 30 GeV/c(2) and 90% confidence level. The results are compared with those from collider searches and used to exclude new parameter space in an isoscalar theory with an axial-vector mediator.
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| 8. |
- Aprile, E., et al.
(författare)
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Effective field theory search for high-energy nuclear recoils using the XENON100 dark matter detector
- 2017
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Ingår i: Physical Review D. - 2470-0010 .- 2470-0029. ; 96:4
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Tidskriftsartikel (refereegranskat)abstract
- We report on weakly interacting massive particles (WIMPs) search results in the XENON100 detector using a nonrelativistic effective field theory approach. The data from science run II (34 kg x 224.6 live days) were reanalyzed, with an increased recoil energy interval compared to previous analyses, ranging from (6.6-240) keV(nr). The data are found to be compatible with the background-only hypothesis. We present 90% confidence level exclusion limits on the coupling constants of WIMP-nucleon effective operators using a binned profile likelihood method. We also consider the case of inelastic WIMP scattering, where incident WIMPs may up-scatter to a higher mass state, and set exclusion limits on this model as well.
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| 9. |
- Aprile, E., et al.
(författare)
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Excess electronic recoil events in XENON1T
- 2020
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Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 102:7
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Tidskriftsartikel (refereegranskat)abstract
- We report results from searches for new physics with low-energy electronic recoil data recorded with the XENONIT detector. With an exposure of 0.65 tonne-years and an unprecedentedly low background rate of 76 +/- 2(stat) events/(tonne x year x keV) between 1 and 30 keV, the data enable one of the most sensitive searches for solar axions, an enhanced neutrino magnetic moment using solar neutrinos, and bosonic dark matter. An excess over known backgrounds is observed at low energies and most prominent between 2 and 3 keV. The solar axion model has a 3.4 sigma significance, and a three-dimensional 90% confidence surface is reported for axion couplings to electrons, photons, and nucleons. This surface is inscribed in the cuboid defined by g(ae) < 3.8 x 10(-12), g(ae)g(an)(eff) < 4.8 x 10(-18), and g(ae)g(a gamma) < 7.7 x 10(-22) GeV-1, and excludes either g(ae) = 0 or g(ae)g(a gamma) = g(ae)ge(an)(eff), = 0. The neutrino magnetic moment signal is similarly favored over background at 3.2 sigma, and a confidence interval of mu(nu) is an element of (1.4, 2.9) x 10(-11) mu(B) (90% C.L.) is reported. Both results are in strong tension with stellar constraints. The excess can also be explained by beta decays of tritium at 3.2 sigma significance with a corresponding tritium concentration in xenon of (6.2 +/- 2.0) x 10(-25) mol/mol. Such a trace amount can neither be confirmed nor excluded with current knowledge of its production and reduction mechanisms. The significances of the solar axion and neutrino magnetic moment hypotheses arc decreased to 2.0 sigma and 0.9 sigma, respectively, if an unconstrained tritium component is included in the fitting. With respect to bosonic dark matter, the excess favors a monoenergetic peak at (2.3 +/- 0.2) keV (68% C.L.) with a 3.0 sigma global (4.0 sigma local) significance over background. This analysis sets the most restrictive direct constraints to date on pseudoscalar and vector bosonic dark matter for most masses between 1 and 210 keV/c(2). We also consider the possibility that Ar-37 may be present in the detector, yielding a 2.82 keV peak from electron capture. Contrary to tritium, the Ar-37 concentration can be tightly constrained and is found to be negligible.
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| 10. |
- Aprile, E., et al.
(författare)
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First Results on the Scalar WIMP-Pion Coupling, Using the XENON1T Experiment
- 2019
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 122:7
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Tidskriftsartikel (refereegranskat)abstract
- We present first results on the scalar coupling of weakly interacting massive particles (WIMPs) to pions from 1 t yr of exposure with the XENON1T experiment. This interaction is generated when the WIMP couples to a virtual pion exchanged between the nucleons in a nucleus. In contrast to most nonrelativistic operators, these pion-exchange currents can be coherently enhanced by the total number of nucleons and therefore may dominate in scenarios where spin-independent WIMP-nucleon interactions are suppressed. Moreover, for natural values of the couplings, they dominate over the spin-dependent channel due to their coherence in the nucleus. Using the signal model of this new WIMP-pion channel, no significant excess is found, leading to an upper limit cross section of 6.4 x 10(-46) cm(2) (90% confidence level) at 30 GeV/c(2) WIMP mass.
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