Development of Muon Drift-Tube Detectors for High-Luminosity Upgrades of the Large Hadron Collider

The muon detectors of the experiments at the Large Hadron Collider (LHC) have to cope with unprecedentedly high neutron and gamma ray background rates. In the forward regions of the muon spectrometer of the ATLAS detector, for instance, counting rates of 1.7 kHz/square cm are reached at the LHC design luminosity. For high-luminosity upgrades of the LHC, up to 10 times higher background rates are expected which require replacement of the muon chambers in the critical detector regions. Tests at the CERN Gamma Irradiation Facility showed that drift-tube detectors with 15 mm diameter aluminum tubes operated with Ar:CO2 (93:7) gas at 3 bar and a maximum drift time of about 200 ns provide efficient and high-resolution muon tracking up to the highest expected rates. For 15 mm tube diameter, space charge effects deteriorating the spatial resolution at high rates are strongly suppressed. The sense wires have to be positioned in the chamber with an accuracy of better than 50 ?micons in order to achieve the desired spatial resolution of a chamber of 50 ?microns up to the highest rates. We report about the design, construction and test of prototype detectors which fulfill these requirements

Limits on the Dipole Moments of the τ\tau-Lepton via the Process $e^{+}e^{-}\to \tau^+ \tau^- \gamma in a Left-Right Symmetric Model

Limits on the anomalous magnetic moment and the electric dipole moment of the $\tau$ lepton are calculated through the reaction $e^{+}e^{-}\to \tau^+ \tau^- \gamma$ at the $Z_1$-pole and in the framework of a left-right symmetric model. The results are based on the recent data reported by the L3 Collaboration at CERN LEP. Due to the stringent limit of the model mixing angle $\phi$, the effect of this angle on the dipole moments is quite small.Comment: 15 pages, 3 figure

Overcoming Barriers to Perinatal Depression Treatment

Background Untreated perinatal depression is common and has deleterious effects on mother, fetus/child and family Despite effective evidence-based treatment for perinatal depression, most women do not get treatment Obstetricians have not traditionally identified and/or responded to the mental health needs of perinatal women Caring and committed providers are frustrated and confused5 and mothers do not feel seen, heard or understood by their providers Implementing supports for perinatal women within the traditional medical model poses many challenges to mental health and obstetric providers MotherWoman is a community-based grassroots organization dedicated to preventing and treating perinatal depression through an innovative organizational change approach, the Community-Based Perinatal Support Model (CPSM). This model includes: Peer-led support groups for perinatal women Organizational change interventions that include structured screening and referral, health care provider trainings and networks, and resource and referral guides Methods Participants Four focus groups with MotherWoman clients, 3 months – 3 years postpartum who self-identified as having experienced perinatal depression or emotional crisis Data collection Focus group probes targeted perceptions of the best practices to engage perinatal women in depression treatment and potential strategies for change Investigators met after each group to record observations and review verbatim notes Participants received gift cards for their participation Data analysis Transcripts were reviewed, segmented, and coded by investigators using an iterative, constant-comparative process to identify emerging themes and recurrent patterns Inter-rater reliability of more than 90% was achieved by two investigators comparing randomly selected coded pages from focus group notes Discussion Despite barriers, numerous facilitators to treatment were identified Supporting women’s mental health during the perinatal time period should ideally be done in both the medical setting and community Supporting the mental health of perinatal women is a fundamental challenge with multiple opportunities for intervention and education Strategies to address perinatal depression include: Offer training to OB/Gyn and mental health providers in the detection and screening of perinatal depression Prepare women for the postpartum period through psychoeducation and peer-support Create flexible treatment options that go beyond medication management and emphasize transition to motherhood Results will Contribute to understanding the barriers and facilitators perinatal women experience when trying to access depression treatment Provide preliminary guidelines for the development of strategies to engage perinatal women in depression treatment Inform the development of interventions that aim to integrate the treatment of perinatal depression into medical setting

A Cosmic Ray Measurement Facility for ATLAS Muon Chambers

Monitored Drift Tube (MDT) chambers will constitute the large majority of precision detectors in the Muon Spectrometer of the ATLAS experiment at the Large Hadron Collider at CERN. For commissioning and calibration of MDT chambers, a Cosmic Ray Measurement Facility is in operation at Munich University. The objectives of this facility are to test the chambers and on-chamber electronics, to map the positions of the anode wires within the chambers with the precision needed for standalone muon momentum measurement in ATLAS, and to gain experience in the operation of the chambers and on-line calibration procedures. Until the start of muon chamber installation in ATLAS, 88 chambers built at the Max Planck Institute for Physics in Munich have to be commissioned and calibrated. With a data taking period of one day individual wire positions can be measured with an accuracy of 8.3 micrometers in the chamber plane and 27 micrometers in the direction perpendicular to that plane.Comment: 14+1 pages, 11 figures, contributed paper to the EPS2003 conference, Aache

Radiative Tau Lepton Pair Production as a Probe of Anomalous Electromagnetic Couplings of the Tau

We calculate the squared matrix element for the process e+ e- --> tau+ tau- gamma allowing for anomalous magnetic and electric dipole moments at the tau tau gamma vertex. No interferences are neglected and no approximations of light fermion masses are made. We show that anomalous moments affect not only the cross section, but also the shape of the photon energy and angular distributions. We also demonstrate that in the case of the anomalous magnetic dipole moment, the contribution from interference involving Standard Model and anomalous amplitudes is significant compared to the contribution from anomalous amplitudes alone. A program to perform the calculation is available and it may be employed as a Monte Carlo generator.Comment: 14 pages, 8 figures submitted to Nuclear Physics

Barriers and Facilitators to Addressing Perinatal Depression in Obstetric Settings

Background: Perinatal depression is common and can cause suffering for mother, fetus/child and family. The perinatal period is an ideal time to detect and treat depression due to regular contact between mothers and health professionals. Despite the opportune time and setting, depression is under-diagnosed and under-treated in the obstetric setting. Caring and committed providers are frustrated and confused, and mothers do not feel heard or understood by their providers. Objectives: (1) Identify postpartum women’s perspective on how perinatal depression is addressed in obstetric settings; (2) Identify strategies for improvement of the delivery of depression care in OB/Gyn settings; and, (3) Inform the development of interventions aimed to improve the delivery of perinatal depression care in obstetric settings. Methods: Four, two hour focus groups were conducted women 3 months – 3 years postpartum (n=27), who identified experiencing symptoms of perinatal depression. Focus group data were analyzed using a grounded theory approach. Results: Participants reported individual, provider and systems-level barriers and facilitators to seeking perinatal depression treatment. Women reported feeling stigmatized, afraid of losing parental rights, and described negative experiences with medical providers, including feeling dismissed by providers and uncomfortable discussing mental health concerns. A lack of provider knowledge and skill sets to address depression was noted by participants. Participants recommended an integrated approach, including psycho-education, peer-support, and provider education/training to improve perinatal depression care in the obstetric setting. Conclusion: Individual, provider and systems-level barriers hinder women from addressing issues of perinatal depression and receiving appropriate care. These data suggest strategies that integrate depression and obstetric care to support OB/Gyns providers and staff in their roles as front line providers to perinatal women. Future efforts could focus on the development of multidisciplinary treatment strategies that utilize patient psychoeducation and provider training and education to overcome barriers and engage women in depression treatment