Lowering the radioactivity of the photomultiplier tubes for the XENON1T dark matter experiment

The low-background, VUV-sensitive 3-inch diameter photomultiplier tube R11410 has been developed by Hamamatsu for dark matter direct detection experiments using liquid xenon as the target material. We present the results from the joint effort between the XENON collaboration and the Hamamatsu company to produce a highly radio-pure photosensor (version R11410-21) for the XENON1T dark matter experiment. After introducing the photosensor and its components, we show the methods and results of the radioactive contamination measurements of the individual materials employed in the photomultiplier production. We then discuss the adopted strategies to reduce the radioactivity of the various PMT versions. Finally, we detail the results from screening 216 tubes with ultra-low background germanium detectors, as well as their implications for the expected electronic and nuclear recoil background of the XENON1T experiment.Comment: 10 pages, 5 figure

Results on ββ\beta\beta decay with emission of two neutrinos or Majorons in 76^{76}Ge from GERDA Phase I

A search for neutrinoless $\beta\beta$ decay processes accompanied with Majoron emission has been performed using data collected during Phase I of the GERmanium Detector Array (GERDA) experiment at the Laboratori Nazionali del Gran Sasso of INFN (Italy). Processes with spectral indices n = 1, 2, 3, 7 were searched for. No signals were found and lower limits of the order of 10$^{23}$ yr on their half-lives were derived, yielding substantially improved results compared to previous experiments with $^{76}$Ge. A new result for the half-life of the neutrino-accompanied $\beta\beta$ decay of $^{76}$Ge with significantly reduced uncertainties is also given, resulting in $T^{2\nu}_{1/2} = (1.926 \pm 0.095)\cdot10^{21}$ yr.Comment: 3 Figure

Limit on the Radiative Neutrinoless Double Electron Capture of 36^{36}Ar from GERDA Phase I

Neutrinoless double electron capture is a process that, if detected, would give evidence of lepton number violation and the Majorana nature of neutrinos. A search for neutrinoless double electron capture of $^{36}$Ar has been performed with germanium detectors installed in liquid argon using data from Phase I of the GERmanium Detector Array (GERDA) experiment at the Gran Sasso Laboratory of INFN, Italy. No signal was observed and an experimental lower limit on the half-life of the radiative neutrinoless double electron capture of $^{36}$Ar was established: $T_{1/2} >$ 3.6 $\times$ 10$^{21}$ yr at 90 % C.I.Comment: 7 pages, 3 figure

A note on comonotonicity and positivity of the control components of decoupled quadratic FBSDE

In this small note we are concerned with the solution of Forward-Backward Stochastic Differential Equations (FBSDE) with drivers that grow quadratically in the control component (quadratic growth FBSDE or qgFBSDE). The main theorem is a comparison result that allows comparing componentwise the signs of the control processes of two different qgFBSDE. As a byproduct one obtains conditions that allow establishing the positivity of the control process.Comment: accepted for publicatio

Applying the strategic-relational approach to urban political ecology: The water management problems of the baixada fluminense, Rio de Janeiro, Brazil

An optimized digital shaping filter has been developed for the Gerda experiment which searches for neutrinoless double beta decay in $$^76$$76Ge. The Gerda Phase\ua0I energy calibration data have been reprocessed and an average improvement of 0.3\ua0keV in energy resolution (FWHM) corresponding to 10\ua0% at the $$Q$$Q value for $$0\nu \beta \beta$$0\u3bd\u3b2\u3b2 decay in $$^76$$76Ge is obtained. This is possible thanks to the enhanced low-frequency noise rejection of this Zero Area Cusp (ZAC) signal shaping filter

Pion, kaon, and proton production in central Pb-Pb Collisions at sNN=2.76\sqrt{s_{NN}} = 2.76 TeV

In this Letter we report the first results on $\pi^\pm$, K$^\pm$, p and $\mathrm {p\overline{p}}$ production at mid-rapidity ($\left|y\right|<0.5$) in central Pb-Pb collisions at $\sqrt{s_{\rm NN}}$ = 2.76 TeV, measured by the ALICE experiment at the LHC. The $p_{\rm T}$ distributions and yields are compared to previous results at $\sqrt{s_{\rm NN}}$ = 200 GeV and expectations from hydrodynamic and thermal models. The spectral shapes indicate a strong increase of the radial flow velocity with $\sqrt{s_{\rm NN}}$, which in hydrodynamic models is expected as a consequence of the increasing particle density. While the ${\rm K}/\pi$ ratio is in line with predictions from the thermal model, the ${\rm p}/\pi$ ratio is found to be lower by a factor of about 1.5. This deviation from thermal model expectations is still to be understood.Comment: 15 pages, 2 captioned figures, 1 table, authors from page 10, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/286

Nurses' perceptions of aids and obstacles to the provision of optimal end of life care in ICU

Contains fulltext : 172380.pdf (publisher's version ) (Open Access

Measurement of charm production at central rapidity in proton-proton collisions at 1as = 2.76 TeV

The pt-differential production cross sections of the prompt (B feed-down subtracted) charmed mesons D0, D+, and D+ in the rapidity range |y| K 12\u3c0+, D+ -> K 12\u3c0+\u3c0+, D+ -> D0\u3c0+, and their charge conjugates, and was performed on a Lint = 1.1 nb 121 event sample collected in 2011 with a minimum-bias trigger. The total charm production cross section at ps = 2.76 TeV and at 7 TeV was evaluated by extrapolating to the full phase space the pt-differential production cross sections at ps = 2.76 TeV and our previous measurements at ps = 7 TeV. The results were compared to existing measurements and to perturbative-QCD calculations. The fraction of cd(bar) D mesons produced in a vector state was also determined

Psychiatrists' perceptions of the clinical importance, assessment and management of patient functioning in schizophrenia in Europe, the Middle East and Africa

Background: It has been estimated that as many as two thirds of patients with schizophrenia are unable to perform basic personal and social roles or activities. Occupational functioning and social functioning, as well as independent living, are considered as core domains of patient functioning. Improvement in patient functioning has also been recognized as an important treatment goal in guidelines and an important outcome by regulatory agencies. Nevertheless, information is lacking on how these aspects are being considered by psychiatrists across the world and how they are being assessed and managed.Methods: The 'Europe, the Middle East and Africa functioning survey' was designed to canvas opinions of psychiatrists across these regions to ascertain their perceptions of the clinical importance, assessment and management of functioning amongst their patients with schizophrenia. The survey comprised 17 questions and was conducted from March to April 2011 in 42 countries. Data collected included the demographics of respondents and their opinions regarding personal and social functioning in patients with schizophrenia.Results: Results were obtained from 4,163 clinicians. Psychiatrists estimated that more than two thirds (70%) of their patients with schizophrenia showed impaired or very poor levels of functioning. The majority of psychiatrists (92%) believed that personal and social functioning was an important treatment goal for patients with schizophrenia, and 91% believed it was an important goal for patients' families. The majority of psychiatrists (55%) assess the personal and social functioning of their patient at each visit; however, 81% reported that they determine the level of functioning through clinical interview and not by using a specific assessment scale. To manage personal and social functioning in their patients, 26% of psychiatrists prefer pharmacological interventions, whereas 46% prefer psychosocial interventions.Conclusion: Psychiatrists recognize that functioning is impaired/very poor in patients with schizophrenia, and there is still an important need to address functioning as a main treatment goal for patients with schizophrenia. © 2013 Gorwood et al.; licensee BioMed Central Ltd