223 research outputs found
Decoupling of the minority PhD talent pool and assistant professor hiring in medical school basic science departments in the US
Abstract Faculty diversity is a longstanding challenge in the US. However, we lack a quantitative and systemic understanding of how the career transitions into assistant professor positions of PhD scientists from underrepresented minority (URM) and well-represented (WR) racial/ethnic backgrounds compare. Between 1980 and 2013, the number of PhD graduates from URM backgrounds increased by a factor of 9.3, compared with a 2.6-fold increase in the number of PhD graduates from WR groups. However, the number of scientists from URM backgrounds hired as assistant professors in medical school basic science departments was not related to the number of potential candidates (R 2 =0.12, p>0.07), whereas there was a strong correlation between these two numbers for scientists from WR backgrounds (R 2 =0.48, p<0.0001). We built and validated a conceptual system dynamics model based on these data that explained 79% of the variance in the hiring of assistant professors and posited no hiring discrimination. Simulations show that, given current transition rates of scientists from URM backgrounds to faculty positions, faculty diversity would not increase significantly through the year 2080 even in the context of an exponential growth in the population of PhD graduates from URM backgrounds, or significant increases in the number of faculty positions. Instead, the simulations showed that diversity increased as more postdoctoral candidates from URM backgrounds transitioned onto the market and were hired
The EDELWEISS Experiment : Status and Outlook
The EDELWEISS Dark Matter search uses low-temperature Ge detectors with heat
and ionisation read- out to identify nuclear recoils induced by elastic
collisions with WIMPs from the galactic halo. Results from the operation of 70
g and 320 g Ge detectors in the low-background environment of the Modane
Underground Laboratory (LSM) are presented.Comment: International Conference on Dark Matter in Astro and Particle Physics
(Dark 2000), Heidelberg, Germany, 10-16 Jul 2000, v3 minor revision
Event categories in the EDELWEISS WIMP search experiment
Four categories of events have been identified in the EDELWEISS-I dark matter
experiment using germanium cryogenic detectors measuring simultaneously charge
and heat signals. These categories of events are interpreted as electron and
nuclear interactions occurring in the volume of the detector, and electron and
nuclear interactions occurring close to the surface of the detectors(10-20 mu-m
of the surface). We discuss the hypothesis that low energy surface nuclear
recoils,which seem to have been unnoticed by previous WIMP searches, may
provide an interpretation of the anomalous events recorded by the UKDMC and
Saclay NaI experiments. The present analysis points to the necessity of taking
into account surface nuclear and electron recoil interactions for a reliable
estimate of background rejection factors.Comment: 11 pages, submitted to Phys. Lett.
SICANE: a Detector Array for the Measurement of Nuclear Recoil Quenching Factors using Monoenergetic Neutron Beam
SICANE is a neutron scattering multidetector facility for the determination
of the quenching factor (ratio of the response to nuclear recoils and to
electrons) of cryogenic detectors used in direct WIMP searches. Well collimated
monoenergetic neutron beams are obtained with inverse (p,n) reactions. The
facility is described, and results obtained for the quenching factors of
scintillation in NaI(Tl) and of heat and ionization in Ge are presented.Comment: 30 pages, Latex, 11 figures. Submitted to NIM
A search for low-mass WIMPs with EDELWEISS-II heat-and-ionization detectors
We report on a search for low-energy (E < 20 keV) WIMP-induced nuclear
recoils using data collected in 2009 - 2010 by EDELWEISS from four germanium
detectors equipped with thermal sensors and an electrode design (ID) which
allows to efficiently reject several sources of background. The data indicate
no evidence for an exponential distribution of low-energy nuclear recoils that
could be attributed to WIMP elastic scattering after an exposure of 113 kg.d.
For WIMPs of mass 10 GeV, the observation of one event in the WIMP search
region results in a 90% CL limit of 1.0x10^-5 pb on the spin-independent
WIMP-nucleon scattering cross-section, which constrains the parameter space
associated with the findings reported by the CoGeNT, DAMA and CRESST
experiments.Comment: PRD rapid communication accepte
Dark Matter Search in the Edelweiss Experiment
Preliminary results obtained with 320g bolometers with simultaneous
ionization and heat measurements are described. After a few weeks of data
taking, data accumulated with one of these detectors are beginning to exclude
the upper part of the DAMA region. Prospects for the present run and the second
stage of the experiment, EDELWEISS-II, using an innovative reversed cryostat
allowing data taking with 100 detectors, are briefly described.Comment: IDM 2000, 3rd International Workshop on the Identification of Dark
Matter, York (GB), 18-22/09/2000, v2.0 minor modification
Search for sub-GeV dark matter via the Migdal effect with an EDELWEISS germanium detector with NbSi transition-edge sensors
The EDELWEISS collaboration reports on the search for dark matter particle interactions via Migdal effect with masses between 32 MeV · câ2 to 2 GeV · câ2 using a 200 g cryogenic Ge detector sensitive to simultaneously heat and ionization signals and operated underground at the Laboratoire Souterrain de Modane in France. The phonon signal was read out using a transition edge sensor made of a NbSi thin film. The detector was biased at 66 V in order to benefit from the Neganov-Trofimov-Luke amplification and resulting in a resolution on the energy of electron recoils of 4.46 eVee (102.58 eV at 66 V) and an analysis threshold of 30 eVee. The sensitivity is limited by a dominant background not associated to charge creation in the detector. The search constrains a new region of parameter space for cross sections down to 10â29 cm2 and masses between 32 and 100 MeV · câ2. The achieved low threshold with the NbSi sensor shows the relevance of its use for out-of-equilibrium phonon sensitive devices for low-mass dark matter searches.The EDELWEISS project is supported in part by the French Agence Nationale pour la Recherche (ANR) and the LabEx Lyon Institute of Origins (ANR-10-LABX 0066) of the UniversitÂŽe de Lyon within the program âInvestissements dâAvenirâ (ANR-11-IDEX-00007), by the P2IO LabEx (ANR-10-LABX-0038) in the framework âInvestissements dâAvenirâ (ANR-11-IDEX-0003-01) managed by the ANR (France), and the Russian Foundation for Basic Research (Grant No. 18-02- 00159). This project has received funding from the European Unionâs Horizon 2020 research and innovation program under the Marie SkĆodowska-Curie Grant Agreement No. 838537. B. J. K. thanks the Spanish Agencia Estatal de InvestigaciĂłn (AEI, MICIU) for the support to the Unidad de Excelencia MarĂa de Maeztu Instituto de FĂsica de Cantabria, Ref. MDM-2017-0765. We thank J. P. Lopez (IP2I) and the Physics Department of UniversitÂŽe Lyon 1 for their contribution to the radioactive sources
Tagging and localization of ionizing events using NbSi transition edge phonon sensors for dark matter searches
In the context of direct searches of sub-GeV dark matter particles with germanium detectors, the
EDELWEISS collaboration has tested a new technique to tag ionizing events using NbSi transition edge
athermal phonon sensors. The emission of the athermal phonons generated by the Neganov-Trofimov-Luke
effect associated with the drift of electrons and holes through the detectors is used to tag ionization events
generated in specific parts of the detector localized in front of the NbSi sensor and to reject by more than
a factor 5 [at 90% confidence level (CL)] the background from heat-only events that dominates the
spectrum above 3 keV. This method is able to improve by a factor of 2.8 the previous limit on spinindependent interactions of 1 GeV=c2 weakly interacting massive particles obtained with the same detector
and dataset but without this tagging technique.The help of the technical staff of the Laboratoire Souterrain de Modane and the participant laboratories is gratefully acknowledged. The EDELWEISS project is supported in part by the French Agence Nationale pour la Recherche (ANR-21-CE31-0004), by the P2IO LabEx (ANR-10-LABX-0038) in the framework âInvestissements dâAvenirâ (ANR-11-IDEX-0003-01), and the LabEx Lyon Institute of Origins (ANR-10-LABX-0066) within the framework of the program France 2030, also operated by the National Research Agency of France. B. J. Kavanagh thanks the Spanish Agencia Estatal de InvestigaciĂłn (AEI, MICIU) for the support to the Unidad de Excelencia MarĂa de Maeztu Instituto de FĂsica de Cantabria, Ref. MDM-2017-0765. B. J. K. also acknowledges funding from the RamĂłn y Cajal Grant RYC2021-034757-I, financed by MCIN/AEI/10.13039/ 501100011033 and by the European Union âNextGenerationEUâ/PRTR
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