Finite size scaling for quantum criticality using the finite-element method

Finite size scaling for the Schr\"{o}dinger equation is a systematic approach to calculate the quantum critical parameters for a given Hamiltonian. This approach has been shown to give very accurate results for critical parameters by using a systematic expansion with global basis-type functions. Recently, the finite element method was shown to be a powerful numerical method for ab initio electronic structure calculations with a variable real-space resolution. In this work, we demonstrate how to obtain quantum critical parameters by combining the finite element method (FEM) with finite size scaling (FSS) using different ab initio approximations and exact formulations. The critical parameters could be atomic nuclear charges, internuclear distances, electron density, disorder, lattice structure, and external fields for stability of atomic, molecular systems and quantum phase transitions of extended systems. To illustrate the effectiveness of this approach we provide detailed calculations of applying FEM to approximate solutions for the two-electron atom with varying nuclear charge; these include Hartree-Fock, density functional theory under the local density approximation, and an "exact"' formulation using FEM. We then use the FSS approach to determine its critical nuclear charge for stability; here, the size of the system is related to the number of elements used in the calculations. Results prove to be in good agreement with previous Slater-basis set calculations and demonstrate that it is possible to combine finite size scaling with the finite-element method by using ab initio calculations to obtain quantum critical parameters. The combined approach provides a promising first-principles approach to describe quantum phase transitions for materials and extended systems.Comment: 15 pages, 19 figures, revision based on suggestions by referee, accepted in Phys. Rev.

Intraoperative radiotherapy in the multidisciplinary treatment of bone sarcomas in children and adolescents

From September 1984 to December 1989, 38 patients of pediatric age with localized bone sarcomas received intraoperative radiotherapy (IORT) as part of a multidisciplinary treatment program. The age ranged from 6 to 21 years. The tumor histologies were 22 osteosarcomas and 16 Ewing's sarcomas. Thirty-four had initial primary disease (90%) and 4 were treated for local recurrence (10%). IORT was used on 32 untreated patients and in 6 previously treated with external beam radiotherapy (EBR). The IORT field included the surgically exposed tumor bed area. Single radiation doses ranging from 10 to 20 Gy were delivered, using 6-20 MeV electron beams. The median follow-up time for the entire group is 25 months (2-65+ months). The projected 5-year disease-free and overall survival rates are 65% and 69%, respectively. One patient developed a local recurrence in each histological group: one chondroblastic osteosarcoma and one cervical Ewing's sarcoma. Six patients died from metastatic progression: 3 initially recurrent tumors and three primary disease cases. Severe neuropathy and soft tissue necrosis were seen in some patients as IORT related complications. IORT is a feasible technique to be integrated in multidisciplinary programs that may promote local control in pediatric and adolescent patients with bone sarcomas. Peripheral nerves are dose-limiting tissue structures for IORT

Nonadiabatic Dynamics of Atoms in Nonuniform Magnetic Fields

Dynamics of neutral atoms in nonuniform magnetic fields, typical of quadrupole magnetic traps, is considered by applying an accurate method for solving nonlinear systems of differential equations. This method is more general than the adiabatic approximation and, thus, permits to check the limits of the latter and also to analyze nonadiabatic regimes of motion. An unusual nonadiabatic regime is found when atoms are confined from one side of the z-axis but are not confined from another side. The lifetime of atoms in a trap in this semi-confining regime can be sufficiently long for accomplishing experiments with a cloud of such atoms. At low temperature, the cloud is ellipsoidal being stretched in the axial direction and moving along the z-axis. The possibility of employing the semi-confining regime for studying the relative motion of one component through another, in a binary mixture of gases is discussed.Comment: 1 file, 17 pages, RevTex, 2 table

Performance of the CMS Cathode Strip Chambers with Cosmic Rays

The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

Performance and Operation of the CMS Electromagnetic Calorimeter

The operation and general performance of the CMS electromagnetic calorimeter using cosmic-ray muons are described. These muons were recorded after the closure of the CMS detector in late 2008. The calorimeter is made of lead tungstate crystals and the overall status of the 75848 channels corresponding to the barrel and endcap detectors is reported. The stability of crucial operational parameters, such as high voltage, temperature and electronic noise, is summarised and the performance of the light monitoring system is presented

Did COVID-19 policies have the same effect on covid-19 incidence among women and men? Evidence from Spain and Switzerland

Objective: This study aimed to investigate how COVID-19 prevention policies influenced the COVID-19 incidence in men and women. Methods: We conducted a retrospective longitudinal study using the Swiss Federal Office of Public Health and the Spanish Ministry of Health surveillance data for February 2020-June 2021 to explore sex and age differences in COVID-19 cases and testing. The female-male incidence rate ratios (IRR) were estimated for each week of the pandemic. We complemented our analysis with qualitative information on relevant containment measures in each country. Results: In Switzerland and in Spain, there was an excess of cases in women of 20-59 years old and 80+. This excess of cases was significant during the waves of the pandemic in both countries. In Switzerland, the biggest difference was observed for the age group 20-29, reaching an excess of 94% of cases compared to men during the first wave of COVID-19 (March-May 2020). The excess of cases in women was greater in Spain than in Switzerland, where it reached 159% for women aged 20-29 during the first wave (March-June 2020). In both countries, the age groups 60-79 had a significant excess of cases in men during the pandemic. Conclusion: COVID-19 public health policies affect men and women in different ways. Our findings highlight the importance of gender-sensitive responses to address a public health crisis

From public health policy to impact for COVID-19: a multi-country case study in Switzerland, Spain, Iran and Pakistan

Objectives: With the application of a systems thinking lens, we aimed to assess the national COVID-19 response across health systems components in Switzerland, Spain, Iran, and Pakistan. Methods: We conducted four case studies on the policy response of national health systems to the early phase of the COVID-19 pandemic. Selected countries include different health system typologies. We collected data prospectively for the period of January-July 2020 on 17 measures of the COVID-19 response recommended by the WHO that encompassed all health systems domains (governance, financing, health workforce, information, medicine and technology and service delivery). We further monitored contextual factors influencing their adoption or deployment. Results: The policies enacted coincided with a decrease in the COVID-19 transmission. However, there was inadequate communication and a perception that the measures were adverse to the economy, weakening political support for their continuation and leading to a rapid resurgence in transmission. Conclusion: Social pressure, religious beliefs, governance structure and level of administrative decentralization or global economic sanctions played a major role in how countries' health systems could respond to the pandemic

The Physics of the B Factories

This work is on the Physics of the B Factories. Part A of this book contains a brief description of the SLAC and KEK B Factories as well as their detectors, BaBar and Belle, and data taking related issues. Part B discusses tools and methods used by the experiments in order to obtain results. The results themselves can be found in Part C

Identification and Filtering of Uncharacteristic Noise in the CMS Hadron Calorimeter

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Performance of CMS hadron calorimeter timing and synchronization using test beam, cosmic ray, and LHC beam data

This paper discusses the design and performance of the time measurement technique and of the synchronization systems of the CMS hadron calorimeter. Time measurement performance results are presented from test beam data taken in the years 2004 and 2006. For hadronic showers of energy greater than 100 GeV, the timing resolution is measured to be about 1.2 ns. Time synchronization and out-of-time background rejection results are presented from the Cosmic Run At Four Tesla and LHC beam runs taken in the Autumn of 2008. The inter-channel synchronization is measured to be within ±2 ns