Search for f1(1285)→π+π−π0f_1(1285) \to \pi^+\pi^-\pi^0 decay with VES detector

The isospin violating decay $f_1(1285)\to\pi^+\pi^-\pi^0$ has been studied at VES facility. This study is based at the statistics acquired in $\pi^- Be$ interactions at 27, 36.6 and 41 GeV/c in diffractive reaction $\pi^- N \to (f_1 \pi^-) N$. The $f_1(1285) \to \pi^+\pi^-\pi^0$ decay is observed. The ratio of decay probabilities $BR(f_1(1285) \to \pi^+\pi^-\pi^0)$ to $BR(f_1(1285) \to \eta \pi^+\pi^-) \cdot BR(\eta \to \gamma\gamma)$ is $\sim\:1.4$.Comment: 10 pages, 8 figures, presented at XII Conference on Hadron Spectroscop

Electromagnetic Cell Level Calibration for ATLAS Tile Calorimeter Modules

We have determined the electromagnetic calibration constants of 11% TileCal modules exposed to electron beams with incident angles of 20 and 90 degrees. The gain of all the calorimeter cells have been pre-equalized using the radioactive Cs-source that will be also used in situ. The average values for these modules are equal to: for the flat filter method 1.154+/-0.002 pC/GeV and 1.192+/-0.002 pC/GeV for 20 and 90 degrees, for the fit method 1.040+/-0.002 pC/GeV and 1.068+/-0.003 pC/GeV, respectively. These average values for all cells of calibrated modules agree with the weighted average calibration constants for separate modules within the errors. Using the individual calibration constants for every module the RMS spread value of constants will be 1.9+/-0.1 %. In the case of the global constant this value will be 2.6+/-0.1 %. Finally, we present the global constants which should be used for the electromagnetic calibration of the ATLAS Tile hadronic calorimeter data in the ATHENA framework. These constants are equal to 1.15 pC/GeV in the case of the flat filter method and 1.04 pC/GeV for the fit one

Разработка макета распределенной сенсорной системы экологического мониторинга

Introduction. In this article, the basic principles of ecological monitoring were considered, and the possibilities of constructing sensor systems were analysed. It was proposed to use the NB-IoT low-energy telecommunication standard as a basic wireless protocol for ecological system development, which ensures effective communication of network devices. A prototype of the system was constructed, and algorithms for receiving and transmitting signals were simulated.Aim. To construct a prototype of a transceiver based on the NB-IoT standard and perform its simulation. To utilize digital twin in MatLab to create the proposed system.Materials and methods. The prototype was constructed using the Xilinx Zedboard evaluation board and transceiver on AD9361 chip, and the simulation was performed using the MatLab 2010 software package.Results. The results of the simulation in the channel with the additive white Gaussian noise (AWGN) were obtained, and the level of the detected synchronization signals of the NB-IoT standard was determined. The receiver and transmitter of the NB-IoT standard were implemented on the Xilinx Zedboard evaluation board. The timing simulation results show that the designed system can be tested in a real environment. The power consumption and resource utilization of the constructed wireless sensor network prototype unit were determined. Conclusion. The results obtained via the simulation process show that the designed prototype of the communication system works correctly, and the produced signal meets all the requirements of the NB-IoT standard. The results can be used for creating a domestic manufactured, specialized integrated chip for data units of ecological monitoring systems.Введение. Рассмотрены основные принципы осуществления экологического мониторинга; проанализированы возможности построения сенсорных систем для осуществления этой задачи. В качестве протокола беспроводной связи создаваемой системы экомониторинга предложено использование телекоммуникационного стандарта с низким энергопотреблением NB-IoT, обеспечивающего эффективное сетевое взаимодействие устройств сети. Проведено моделирование системы и макетирование алгоритмов приема и передачи сигналов.Цель работы. Построить макет приемопередатчика по стандарту NB-IoT и провести его имитационное моделирование. Использовать маршрут создания системы с формированием ее цифрового двойника в MatLab.Материалы и методы. Прототип построен c использованием отладочной платы Xilinx Zedboard и приемопередатчика на основе микросхемы AD9361, а имитационная модель – при помощи пакета программ MatLab 2010.Результаты. Получены результаты имитационного моделирования в канале с аддитивным белым гауссовским шумом, определена мощность обнаруживаемых сигналов синхронизации стандарта NB-IoT. Приемник и передатчик стандарта NB-IoT реализованы на плате Xilinx Zedboard. Временны́е диаграммы, полученные в ходе тестирования макета, демонстрируют, что разработанная система готова к тестированию в реальной среде. Определены энергетические и ресурсные затраты разработанного макета узла беспроводной сенсорной сети.Заключение. Полученные результаты моделирования показывают, что разработанная модель системы связи функционирует корректно и формируемый сигнал передатчика соответствует требованиям стандарта NB-IoT. Результаты разработки можно использовать для создания отечественной микросхемы узла сбора и передачи данных мониторинга окружающей среды

Hadron Energy Reconstruction for the ATLAS Calorimetry in the Framework of the Non-parametrical Method

This paper discusses hadron energy reconstruction for the ATLAS barrel prototype combined calorimeter (consisting of a lead-liquid argon electromagnetic part and an iron-scintillator hadronic part) in the framework of the non-parametrical method. The non-parametrical method utilizes only the known $e/h$ ratios and the electron calibration constants and does not require the determination of any parameters by a minimization technique. Thus, this technique lends itself to an easy use in a first level trigger. The reconstructed mean values of the hadron energies are within $\pm 1$ of the true values and the fractional energy resolution is $[(58\pm3)/\sqrt{E}+(2.5\pm0.3)$. The value of the $e/h$ ratio obtained for the electromagnetic compartment of the combined calorimeter is $1.74\pm0.04$ and agrees with the prediction that $e/h > 1.7$ for this electromagnetic calorimeter. Results of a study of the longitudinal hadronic shower development are also presented. The data have been taken in the H8 beam line of the CERN SPS using pions of energies from 10 to 300 GeV.Comment: 33 pages, 13 figures, Will be published in NIM

Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal

Standalone vertex finding in the ATLAS muon spectrometer

A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at √s = 7 TeV collected with the ATLAS detector at the LHC during 2011

Measurements of Higgs boson production and couplings in diboson final states with the ATLAS detector at the LHC

Measurements are presented of production properties and couplings of the recently discovered Higgs boson using the decays into boson pairs, H →γ γ, H → Z Z∗ →4l and H →W W∗ →lνlν. The results are based on the complete pp collision data sample recorded by the ATLAS experiment at the CERN Large Hadron Collider at centre-of-mass energies of √s = 7 TeV and √s = 8 TeV, corresponding to an integrated luminosity of about 25 fb−1. Evidence for Higgs boson production through vector-boson fusion is reported. Results of combined fits probing Higgs boson couplings to fermions and bosons, as well as anomalous contributions to loop-induced production and decay modes, are presented. All measurements are consistent with expectations for the Standard Model Higgs boson

Measurement of the top quark pair cross section with ATLAS in pp collisions at √s=7 TeV using final states with an electron or a muon and a hadronically decaying τ lepton

A measurement of the cross section of top quark pair production in proton-proton collisions recorded with the ATLAS detector at the Large Hadron Collider at a centre-of-mass energy of 7 TeV is reported. The data sample used corresponds to an integrated luminosity of 2.05 fb -1. Events with an isolated electron or muon and a τ lepton decaying hadronically are used. In addition, a large missing transverse momentum and two or more energetic jets are required. At least one of the jets must be identified as originating from a b quark. The measured cross section, σtt-=186±13(stat.)±20(syst.)±7(lumi.) pb, is in good agreement with the Standard Model prediction