We report results from searches for new physics with low-energy electronic recoil data recorded with the XENON1T detector. With an exposure of 0.65 t-y and an unprecedentedly low background rate of ...\(76\pm2\) events/(t y keV) between 1 and 30 keV, the data enables sensitive searches for solar axions, an enhanced neutrino magnetic moment, 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 3D 90% confidence surface is reported for axion couplings to electrons, photons, and nucleons. This surface is inscribed in the cuboid defined by \(g_{ae}<3.8 \times 10^{-12}\), \(g_{ae}g_{an}^{eff}<4.8\times 10^{-18}\), and \(g_{ae}g_{a\gamma}<7.7\times10^{-22} GeV^{-1}\), and excludes either \(g_{ae}=0\) or \(g_{ae}g_{a\gamma}=g_{ae}g_{an}^{eff}=0\). The neutrino magnetic moment signal is similarly favored over background at 3.2\(\sigma\) and a confidence interval of \(\mu_{\nu} \in (1.4,2.9)\times10^{-11}\mu_B\) (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\(\sigma\) with a trace amount that 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 are reduced 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 (\(2.3\pm0.2\)) keV (68% C.L.) with a 3.0\(\sigma\) global (4.0\(\sigma\) local) significance. We also consider the possibility that \(^{37}\)Ar may be present in the detector and yield a 2.82 keV peak. Contrary to tritium, the \(^{37}\)Ar concentration can be tightly constrained and is found to be negligible.
Phys. Rev. Lett. 126, 091301 (2021) We report on a search for nuclear recoil signals from solar $^8$B neutrinos
elastically scattering off xenon nuclei in XENON1T data, lowering the energy
threshold ...from 2.6 keV to 1.6 keV. We develop a variety of novel techniques to
limit the resulting increase in backgrounds near the threshold. No significant
$^8$B neutrino-like excess is found in an exposure of 0.6 t $\times$ y. For the
first time, we use the non-detection of solar neutrinos to constrain the light
yield from 1-2 keV nuclear recoils in liquid xenon, as well as non-standard
neutrino-quark interactions. Finally, we improve upon world-leading constraints
on dark matter-nucleus interactions for dark matter masses between 3 GeV/c$^2$
and 11 GeV/c$^2$ by as much as an order of magnitude.
Xenon dual-phase time projection chambers designed to search for Weakly Interacting Massive Particles have so far shown a relative energy resolution which degrades with energy above \(\sim\)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 \(^{136}\)Xe at its \(Q\)-value, \(Q_{\beta\beta}\simeq\) 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\(\pm\)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.
Computer Simulations of Cylindrically Confined Nematics Chiccoli, C.; Pasini, P.; Semeria, F. ...
Molecular crystals and liquid crystals science and technology. Section A, Molecular crystals and liquid crystals,
11/1/1996, Letnik:
290, Številka:
1
Journal Article, Conference Proceeding
A Monte Carlo simulation of a nematic Lebwohl-Lasher liquid crystal confined to a cylindrical pore is presented. We have calculated the ordering and the molecular organisation inside the cavity for ...cylinders of different size when homeotropic radial boundary conditions and different anchoring strengths are employed. We have not observed escaped radial configurations in the organisations obtained.
The goal of the MRPC–detector production for the ALICE TOF is to guarantee the same excellent performances obtained so far with all the prototypes. A set of quality assurance tests has been developed ...for this purpose; these tests are applied both to the single chamber components and to the assembled detectors. In this paper the results of these tests over a few hundreds MRPCs of the mass production will be presented.
We present Monte Carlo simulations of nematic droplets with toroidal boundary conditions (TBC) and various anchoring strengths and we investigate the orientational order and the molecular ...organizations in these systems that mimic polymer dispersed liquid crystals (PDLC).
PACS: 02.50 Monte Carlo studies
PACS: 61.30.Jf Defects in liquid crystals
PACS: 61.30.Gd Orientational order of liquid crystals
PACS: 64.70.M Liquid Crystals phase transitions.
Monte Carlo Simulations of Model Nematic Droplets Chiccoli, C.; Pasini, P.; Semeria, F. ...
Molecular crystals and liquid crystals science and technology. Section A, Molecular crystals and liquid crystals,
02/1992, Letnik:
212, Številka:
1
Journal Article
Odprti dostop
We present Monte Carlo computer simulations of model nematic droplets with radial boundary conditions and various anchoring strengths and we investigate the orientational order and the molecular ...organizations in these systems that mimic polymer dispersed liquid crystals (PDLC). We find a hedgehog organization at high anchoring strengths and that an ordered domain is created in the droplet center at lower strengths.
We report on a search for nuclear recoil signals from solar \(^8\)B neutrinos elastically scattering off xenon nuclei in XENON1T data, lowering the energy threshold from 2.6 keV to 1.6 keV. We ...develop a variety of novel techniques to limit the resulting increase in backgrounds near the threshold. No significant \(^8\)B neutrino-like excess is found in an exposure of 0.6 t \(\times\) y. For the first time, we use the non-detection of solar neutrinos to constrain the light yield from 1-2 keV nuclear recoils in liquid xenon, as well as non-standard neutrino-quark interactions. Finally, we improve upon world-leading constraints on dark matter-nucleus interactions for dark matter masses between 3 GeV/c\(^2\) and 11 GeV/c\(^2\) by as much as an order of magnitude.
