Search for heavy and excited leptons at LEP

New particle searches are ongoing at the large electron positron collider (LEP) running yearly at increasing centre-of-mass energies. The searches for heavy stable and unstable leptons performed by the four LEP experiments (ALEPH, DELPHI, L3 and OPAL) are summarised, followed by a description of the searches for excited leptons. Experimental signatures and results, including the most recent data analysed, are presented. (17 refs)

Preliminary investigation of pressure influence on multiphase heat transfer report no. ii

Pressure and surface condition in multiphase boiling heat transfe

Effects of spiritual care training for palliative care professionals

Little is known about the effects of spiritual care training for professionals in palliative medicine. We therefore investigated prospectively the effects of such training over a six-month period. All 63 participants of the three and a half-day training were asked to fill out three questionnaires: before and after the training, as well as six months later. The questionnaires included demographic data, numeric rating scales about general attitudes towards the work in palliative care, the Self-Transcendence Scale (STS), the spiritual subscale of the Functional Assessment of Chronic Illness Therapy (FACIT-Sp) and the Idler Index of Religiosity (IIR). Forty-eight participants (76) completed all three questionnaires (91 women, median age 49 years; 51 nurses, 16 hospice volunteers, 14 physicians).Significant and sustained improvements were found in self-perceived compassion for the dying (after the training: P =0.002; 6 months later: P=0.025), compassion for oneself (P < 0.001; P =0.013), attitude towards one's family (P =0.001; P =0.031), satisfaction with work (P < 0.001; P =0.039), reduction in work-related stress (P < 0.001; P =0.033), and attitude towards colleagues (P =0.039; P =0.040), as well as in the FACIT-Sp (P < 0.001; P =0.040). Our results suggest that the spiritual care training had a positive influence on the spiritual well-being and the attitudes of the participating palliative care professionals which was preserved over a six-month period

Development and Characterisation of a Gas System and its Associated Slow-Control System for an ATLAS Small-Strip Thin Gap Chamber Testing Facility

A quality assurance and performance qualification laboratory was built at McGill University for the Canadian-made small-strip Thin Gap Chamber (sTGC) muon detectors produced for the 2019-2020 ATLAS experiment muon spectrometer upgrade. The facility uses cosmic rays as a muon source to ionise the quenching gas mixture of pentane and carbon dioxide flowing through the sTGC detector. A gas system was developed and characterised for this purpose, with a simple and efficient gas condenser design utilizing a Peltier thermoelectric cooler (TEC). The gas system was tested to provide the desired 45 vol% pentane concentration. For continuous operations, a state-machine system was implemented with alerting and remote monitoring features to run all cosmic-ray data-acquisition associated slow-control systems, such as high/low voltage, gas system and environmental monitoring, in a safe and continuous mode, even in the absence of an operator.Comment: 23 pages, LaTeX, 14 figures, 4 tables, proof corrections for Journal of Instrumentation (JINST), including corrected Fig. 8b

Background risk of breast cancer and the association between physical activity and mammographic density

This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/ by/4.0

Interaction between vortices in models with two order parameters

The interaction energy and force between widely separated strings is analyzed in a field theory having applications to superconducting cosmic strings, the SO(5) model of high-temperature superconductivity, and solitons in nonlinear optics. The field theory has two order parameters, one of which is broken in the vacuum (giving rise to strings), the other of which is unbroken in the vacuum but which could nonetheless be broken in the core of the string. If this does occur, there is an effect on the energetics of widely separated strings. This effect is important if the length scale of this second order parameter is longer than that of the other fields in the problem.Comment: 11 pages, 3 figures. Minor changes in the text. Accepted for publication in Phys. Rev.

Implementation and Performance of the ATLAS Second Level Jet Trigger

ATLAS is one of the four major LHC experiments, designed to cover a wide range of physics topics. In order to cope with a rate of 40 MHz and 25 interactions per bunch crossing, the ATLAS trigger system is divided in three different levels. The first one (LVL1, hardware based) identifies signatures in 2 microseconds that are confirmed by the the following trigger levels (software based). The Second Level Trigger (LVL2) only looks at a region of the space around the LVL1 signature (called Region of Interest or ROI), confirming/rejecting the event in about 10 ms, while the Event Filter (Third Level Trigger, EF) has potential full event access and larger processing times, of the order of 1 s. The jet selection starts at the LVL1 with dedicated processors that search for high ET hadronic energy depositions. At the LVL2, the jet signatures are verified with the execution of a dedicated, fast jet reconstruction algorithm. Given the fact that the main jet's background are jets,the energy calibration at the LVL2 is one of the major dificulties of this trigger, allowing to distinguish low/high energy jets. The algorithm for the calibration has been chosen to be fast and robust, with a good performance. The other major dificulty is the execution time of the algorithm,dominated by the data unpacking time due to the large sizes of the jet ROI. In order to reduce the execution time, three possible granularities have been proposed and are being evaluated: cell based (standard), energy sums calculated at each Fron-End Board (FEB) and the use of the LVL1 Trigger Towers. The FEB and Trigger Tower granularities are also being used/evaluated for the reconstruction of the missing ET triggers at the Event Filter, given the short times available to process the full event. In this presentation, the design and implementation of the jet trigger of ATLAS will be discussed in detail, emphasasing the major dificulties of each selection step. The performance of the jet algorithm, including timing, eficiencies and rates will also be shown, with detailed comparisons of the different unpacking modes

Foreground Detection Using the Choquet Integral

International audienceForeground Detection is a key step in background subtraction problem. This approach consists in the detection of moving objects from static cameras through a classification process of pixels as foreground or background. The presence of some critical situations i.e noise, illumination changes and structural background changes produces an uncertainty in the classification of image pixels which can generate false detections. In this context, we propose a fuzzy approach using the Choquet integral to avoid the uncertainty in the classification. The experiments on different video datasets have been realized by testing different color space and by fusing color and texture features. The proposed method is characterized through robustness against illumination changes, shadows and little background changes, and it is validated with the experimental results