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Calvén, Jakob
Publications (10 of 15) Show all publications
Aprile, E., Aalbers, J., Agostini, F., Alfonsi, M., Amaro, F. D., Anthony, M., . . . Zhu, T. (2018). Signal yields of keV electronic recoils and their discrimination from nuclear recoils in liquid xenon. Physical Review D: covering particles, fields, gravitation, and cosmology, 97(9), Article ID 092007.
Open this publication in new window or tab >>Signal yields of keV electronic recoils and their discrimination from nuclear recoils in liquid xenon
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2018 (English)In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 97, no 9, article id 092007Article in journal (Refereed) Published
Abstract [en]

We report on the response of liquid xenon to low energy electronic recoils below 15 keV from beta decays of tritium at drift fields of 92 V/cm, 154 V/cm and 366 V/cm using the XENON100 detector. A data-to-simulation fitting method based on Markov Chain Monte Carlo is used to extract the photon yields and recombination fluctuations from the experimental data. The photon yields measured at the two lower fields are in agreement with those from literature; additional measurements at a higher field of 366 V/cm are presented. The electronic and nuclear recoil discrimination as well as its dependence on the drift field and photon detection efficiency are investigated at these low energies. The results provide new measurements in the energy region of interest for dark matter searches using liquid xenon.
Keywords
Particle dark matter
National Category
Physical Sciences
Identifiers
urn:nbn:se:su:diva-157725 (URN)10.1103/PhysRevD.97.092007 (DOI)000433066800001 ()2-s2.0-85048687794 (Scopus ID)
Available from: 2018-08-07 Created: 2018-08-07 Last updated: 2022-10-26Bibliographically approved
Aprile, E., Aalbers, J., Agostini, F., Alfonsi, M., Amaro, F. D., Anthony, M., . . . Farmer, B. (2017). Effective field theory search for high-energy nuclear recoils using the XENON100 dark matter detector. Physical Review D: covering particles, fields, gravitation, and cosmology, 96(4), Article ID 042004.
Open this publication in new window or tab >>Effective field theory search for high-energy nuclear recoils using the XENON100 dark matter detector
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2017 (English)In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 96, no 4, article id 042004Article in journal (Refereed) Published
Abstract [en]

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.
National Category
Physical Sciences
Identifiers
urn:nbn:se:su:diva-146992 (URN)10.1103/PhysRevD.96.042004 (DOI)000408704800001 ()2-s2.0-85029119274 (Scopus ID)
Available from: 2017-09-18 Created: 2017-09-18 Last updated: 2022-10-19Bibliographically approved
Aprile, E., Aalbers, J., Agostini, F., Alfonsi, M., Amaro, F. D., Anthony, M., . . . Zhu, T. (2017). First Dark Matter Search Results from the XENON1T Experiment. Physical Review Letters, 119(18), Article ID 181301.
Open this publication in new window or tab >>First Dark Matter Search Results from the XENON1T Experiment
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2017 (English)In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 119, no 18, article id 181301Article in journal (Refereed) Published
Abstract [en]

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.
National Category
Physical Sciences
Research subject
Physics
Identifiers
urn:nbn:se:su:diva-148981 (URN)10.1103/PhysRevLett.119.181301 (DOI)000413903200005 ()
Available from: 2017-12-04 Created: 2017-12-04 Last updated: 2022-03-23Bibliographically approved
Aprile, E., Aalbers, J., Agostini, F., Alfonsi, M., Amaro, F. D., Anthony, M., . . . Nisi, S. (2017). Material radioassay and selection for the XENON1T dark matter experiment. European Physical Journal C, 77(12), Article ID 890.
Open this publication in new window or tab >>Material radioassay and selection for the XENON1T dark matter experiment
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2017 (English)In: European Physical Journal C, ISSN 1434-6044, E-ISSN 1434-6052, Vol. 77, no 12, article id 890Article in journal (Refereed) Published
Abstract [en]

The XENON1T dark matter experiment aims to detect weakly interactingmassive particles (WIMPs) through low-energy interactions with xenon atoms. To detect such a rare event necessitates the use of radiopure materials to minimize the number of background events within the expected WIMP signal region. In this paper we report the results of an extensive material radioassay campaign for the XENON1T experiment. Using gamma-ray spectroscopy and mass spectrometry techniques, systematic measurements of trace radioactive impurities in over one hundred samples within a wide range of materials were performed. The measured activities allowed for stringent selection and placement of materials during the detector construction phase and provided the input for XENON1T detection sensitivity estimates through Monte Carlo simulations.
National Category
Physical Sciences
Identifiers
urn:nbn:se:su:diva-150920 (URN)10.1140/epjc/s10052-017-5329-0 (DOI)000418559000001 ()
Available from: 2018-01-09 Created: 2018-01-09 Last updated: 2022-03-23Bibliographically approved
Aprile, E., Aalbers, J., Agostini, F., Alfonsi, M., Amaro, F. D., Anthony, M., . . . Cristescu, I. (2017). Online Rn-222 removal by cryogenic distillation in the XENON100 experiment. European Physical Journal C, 77(6), Article ID 358.
Open this publication in new window or tab >>Online Rn-222 removal by cryogenic distillation in the XENON100 experiment
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2017 (English)In: European Physical Journal C, ISSN 1434-6044, E-ISSN 1434-6052, Vol. 77, no 6, article id 358Article in journal (Refereed) Published
Abstract [en]

We describe the purification of xenon from traces of the radioactive noble gas radon using a cryogenic distillation column. The distillation column was integrated into the gas purification loop of the XENON100 detector for online radon removal. This enabled us to significantly reduce the constant Rn-222 background originating from radon emanation. After inserting an auxiliary 222Rn emanation source in the gas loop, we determined a radon reduction factor of R > 27 (95% C.L.) for the distillation column by monitoring the Rn-222 activity concentration inside the XENON100 detector.
National Category
Physical Sciences
Identifiers
urn:nbn:se:su:diva-144648 (URN)10.1140/epjc/s10052-017-4902-x (DOI)000402676000001 ()
Available from: 2017-06-27 Created: 2017-06-27 Last updated: 2022-03-23Bibliographically approved
Aprile, E., Aalbers, J., Agostini, F., Alfonsi, M., Amaro, F. D., Anthony, M., . . . Cristescu, I. (2017). Removing krypton from xenon by cryogenic distillation to the ppq level. European Physical Journal C, 77(5), Article ID 275.
Open this publication in new window or tab >>Removing krypton from xenon by cryogenic distillation to the ppq level
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2017 (English)In: European Physical Journal C, ISSN 1434-6044, E-ISSN 1434-6052, Vol. 77, no 5, article id 275Article in journal (Refereed) Published
Abstract [en]

The XENON1T experiment aims for the direct detection of dark matter in a detector filled with 3.3 tons of liquid xenon. In order to achieve the desired sensitivity, the background induced by radioactive decays inside the detector has to be sufficiently low. One major contributor is the beta-emitter Kr-85 which is present in the xenon. For XENON1T a concentration of natural krypton in xenon Kr-nat/Xe < 200 ppq (parts per quadrillion, 1 ppq = 10(-15) mol/mol) is required. In this work, the design, construction and test of a novel cryogenic distillation column using the common McCabe-Thiele approach is described. The system demonstrated a krypton reduction factor of 6.4 . 10(5) with thermodynamic stability at process speeds above 3 kg/h. The resulting concentration of natKr/Xe < 26 ppq is the lowest ever achieved, almost one order of magnitude below the requirements for XENON1T and even sufficient for future dark matter experiments using liquid xenon, such as XENONnT and DARWIN.
National Category
Physical Sciences
Identifiers
urn:nbn:se:su:diva-143454 (URN)10.1140/epjc/s10052-017-4757-1 (DOI)000400642800003 ()
Available from: 2017-06-07 Created: 2017-06-07 Last updated: 2022-03-23Bibliographically approved
Aprile, E., Aalbers, J., Agostini, F., Alfonsi, M., Amaro, F. D., Anthony, M., . . . Zhang, Y. (2017). Results from a calibration of XENON100 using a source of dissolved radon-220. Physical Review D: covering particles, fields, gravitation, and cosmology, 95(7), Article ID 072008.
Open this publication in new window or tab >>Results from a calibration of XENON100 using a source of dissolved radon-220
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2017 (English)In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 95, no 7, article id 072008Article in journal (Refereed) Published
Abstract [en]

A Rn-220 source is deployed on the XENON100 dark matter detector in order to address the challenges in calibration of tonne-scale liquid noble element detectors. We show that the Pb-212 beta emission can be used for low-energy electronic recoil calibration in searches for dark matter. The isotope spreads throughout the entire active region of the detector, and its activity naturally decays below background level within a week after the source is closed. We find no increase in the activity of the troublesome Rn-222 background after calibration. Alpha emitters are also distributed throughout the detector and facilitate calibration of its response to Rn-222. Using the delayed coincidence of Rn-220-Po-216, we map for the first time the convective motion of particles in the XENON100 detector. Additionally, we make a competitive measurement of the half-life of Po-212, t(1/2) = (293.9 +/- (1.0)(stat) +/- (0.6)(sys)) ns.
National Category
Astronomy, Astrophysics and Cosmology
Identifiers
urn:nbn:se:su:diva-143476 (URN)10.1103/PhysRevD.95.072008 (DOI)000399945500001 ()2-s2.0-85019624109 (Scopus ID)
Available from: 2017-05-30 Created: 2017-05-30 Last updated: 2022-10-20Bibliographically approved
Aprile, E., Aalbers, J., Agostini, F., Alfonsi, M., Althueser, L., Amaro, F. D., . . . Zhu, T. (2017). Search for bosonic super-WIMP interactions with the XENON100 experiment. Physical Review D: covering particles, fields, gravitation, and cosmology, 96(12), Article ID 122002.
Open this publication in new window or tab >>Search for bosonic super-WIMP interactions with the XENON100 experiment
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2017 (English)In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 96, no 12, article id 122002Article in journal (Refereed) Published
Abstract [en]

We present results of searches for vector and pseudoscalar bosonic super-weakly interacting massive particles (WIMPs), which are dark matter candidates with masses at the keV-scale, with the XENON100 experiment. XENON100 is a dual-phase xenon time projection chamber operated at the Laboratori Nazionali del Gran Sasso. A profile likelihood analysis of data with an exposure of 224.6 live days x34 kg showed no evidence for a signal above the expected background. We thus obtain new and stringent upper limits in the (8-125) keV/c(2) mass range, excluding couplings to electrons with coupling constants of g(ae) > 3 x 10(-13) for pseudo-scalar and alpha'/alpha > 2 x 10(-28) for vector super-WIMPs, respectively. These limits are derived under the assumption that super-WIMPs constitute all of the dark matter in our galaxy.
National Category
Physical Sciences
Identifiers
urn:nbn:se:su:diva-150923 (URN)10.1103/PhysRevD.96.122002 (DOI)000417477700002 ()2-s2.0-85040174172 (Scopus ID)
Available from: 2018-01-09 Created: 2018-01-09 Last updated: 2022-10-20Bibliographically approved
Aprile, E., Aalbers, J., Agostini, F., Alfonsi, M., Amaro, F. D., Anthony, M., . . . Zhang, Y. (2017). Search for Electronic Recoil Event Rate Modulation with 4 Years of XENON100 Data. Physical Review Letters, 118(10), Article ID 101101.
Open this publication in new window or tab >>Search for Electronic Recoil Event Rate Modulation with 4 Years of XENON100 Data
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2017 (English)In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 118, no 10, article id 101101Article in journal (Refereed) Published
Abstract [en]

We report on a search for electronic recoil event rate modulation signatures in the XENON100 data accumulated over a period of 4 yr, from January 2010 to January 2014. A profile likelihood method, which incorporates the stability of the XENON100 detector and the known electronic recoil background model, is used to quantify the significance of periodicity in the time distribution of events. There is a weak modulation signature at a period of 431(-14)(+16) day in the low energy region of (2.0-5.8) keV in the single scatter event sample, with a global significance of 1.9 sigma; however, no other more significant modulation is observed. The significance of an annual modulation signature drops from 2.8 sigma, from a previous analysis of a subset of this data, to 1.8 sigma with all data combined. Single scatter events in the low energy region are thus used to exclude the DAMA/LIBRA annual modulation as being due to dark matter electron interactions via axial vector coupling at 5.7 sigma.
National Category
Physical Sciences
Research subject
Physics
Identifiers
urn:nbn:se:su:diva-141208 (URN)10.1103/PhysRevLett.118.101101 (DOI)000396046100002 ()28339273 (PubMedID)2-s2.0-85015038881 (Scopus ID)
Available from: 2017-04-25 Created: 2017-04-25 Last updated: 2022-10-20Bibliographically approved
Aprile, E., Aalbers, J., Agostini, F., Alfonsi, M., Amaro, F. D., Anthony, M., . . . Zhang, Y. (2017). Search for magnetic inelastic dark matter with XENON100. Journal of Cosmology and Astroparticle Physics (10), Article ID 039.
Open this publication in new window or tab >>Search for magnetic inelastic dark matter with XENON100
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2017 (English)In: Journal of Cosmology and Astroparticle Physics, E-ISSN 1475-7516, no 10, article id 039Article in journal (Refereed) Published
Abstract [en]

We present the first search for dark matter-induced delayed coincidence signals in a dual-phase xenon time projection chamber, using the 224.6 live days of the XENON100 science run II. This very distinct signature is predicted in the framework of magnetic inelastic dark matter which has been proposed to reconcile the modulation signal reported by the DAMA/LIBRA collaboration with the null results from other direct detection experiments. No candidate event has been found in the region of interest and upper limits on the WIMP's magnetic dipole moment are derived. The scenarios proposed to explain the DAMA/LIBRA modulation signal by magnetic inelastic dark matter interactions of WIMPs with masses of 58.0 GeV/c(2) and 122.7 GeV/c(2) are excluded at 3.3 sigma and 9.3 sigma, respectively.
Keywords
dark matter detectors, dark matter experiments
National Category
Physical Sciences
Identifiers
urn:nbn:se:su:diva-148935 (URN)10.1088/1475-7516/2017/10/039 (DOI)000413747500002 ()2-s2.0-85039964662 (Scopus ID)
Available from: 2017-11-14 Created: 2017-11-14 Last updated: 2023-03-28Bibliographically approved
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