Search results for "PARTICLE PHYSICS"
showing 10 items of 6826 documents
Searches for lepton number violation and resonances in K± → πμμ decays
2017
The NA48/2 experiment at CERN collected a large sample of charged kaon decays to final states with multiple charged particles in 2003–2004. A new upper limit on the rate of the lepton number violating decay K±→π∓μ±μ± is reported: B(K±→π∓μ±μ±)<8.6×10−11 at 90% CL. Searches for two-body resonances X in K±→πμμ decays (such as heavy neutral leptons N4 and inflatons χ ) are also presented. In the absence of signals, upper limits are set on the products of branching fractions B(K±→μ±N4)B(N4→πμ) and B(K±→π±X)B(X→μ+μ−) for ranges of assumed resonance masses and lifetimes. The limits are in the (10−11,10−9) range for resonance lifetimes below 100 ps.
Search for pair production of first or second generation leptoquarks in proton-proton collisions at sqrt(s)=7 TeV using the ATLAS detector at the LHC
2011
This paper describes searches for the pair production of first or second generation scalar leptoquarks using 35 pb−1 of proton-proton collision data recorded by the ATLAS detector at √s=7 TeV. Leptoquarks are searched in events with two oppositely-charged muons or electrons and at least two jets, and in events with one muon or electron, missing transverse momentum and at least two jets. After event selection, the observed yields are consistent with the predicted backgrounds. Leptoquark production is excluded at the 95% CL for masses MLQ<376 (319) GeV and MLQ<422 (362) GeV for first and second generation scalar leptoquarks, respectively, when assuming the branching fraction of a leptoquark…
Seasonal Modulation of the $^7$Be Solar Neutrino Rate in Borexino
2017
We detected the seasonal modulation of the $^7$Be neutrino interaction rate with the Borexino detector at the Laboratori Nazionali del Gran Sasso in Italy. The period, amplitude, and phase of the observed time evolution of the signal are consistent with its solar origin, and the absence of an annual modulation is rejected at 99.99\% C.L. The data are analyzed using three methods: the sinusoidal fit, the Lomb-Scargle and the Empirical Mode Decomposition techniques, which all yield results in excellent agreement.
Constructions, Claims, Resonance, Reflexivity: Language and Market Categorization
2020
doi: 10.1177/2631787720968561 Studies on market categorization exhibit substantial agreement that language plays a central role in articulating and constructing meanings among market participants and crafting consensus to produce a collective of interacting market actors. The purpose of this paper is to take stock of the growing body of research on language and market categories. This review has two aims. We begin by identifying how scholars have applied a variety of language constructs in category research, providing an understanding of the differences between these constructs and elaborating their uses and functions in the studies on market categorization. The second part of the review th…
STATUS OF STRANGENESS ELECTRO-PRODUCTION AT MAMI
2009
At the Institut für Kernphysik in Mainz, Germany, the microtron MAMI has been upgraded to 1.5 GeV electron beam energy and can now be used to study strange hadronic systems. The magnetic spectrometer KAOS from GSI was dismantled and re-installed in the spectrometer facility operated by the A1 collaboration. The spectrometer's primary purpose is to study strangeness electro-production. Its compact design and its capability to detect negative and positive charged particles simultaneously under forward scattering angles complements the existing spectrometers. In 2008, an important milestone has been reached by the successful measurement of kaon production off a liquid hydrogen target. The ide…
New Capabilities of the FLUKA Multi-Purpose Code
2022
We would like to deeply thank the CERN Knowledge Transfer and Legal Service teams for their essential and extended support. Our appreciation also goes to the FLUKA.CERN Collaboration Board members for their strong commitment.
Many-particle approach to the image-charge effect
2011
Microscopical systems of molecules and atomic chains are studied to obtain information about quantum-transport phenomena. Both exact diagonalization method through second quantization and perturbation theory approach with Feynman diagrams are described, and then the energy spectra for the studied systems are calculated using the two methods.
Breakdown of the isobaric multiplet mass equation (IMME) at A=33, T=3/2
2000
Mass measurements on 3 3 , 3 4 , 4 2 , 4 3 Ar were performed using the Penning trap mass spectrometer ISOLTRAP and a newly constructed linear Paul trap. This arrangement allowed us, for the first time, to extend Penning trap mass measurements to nuclides with half-lives below one second ( 33 Ar : T 1 / 2 = 174 ms ). A mass accuracy of about 10 − 7 ( δ m ≈ 4 keV ) was achieved for all investigated nuclides. The isobaric multiplet mass equation was checked for the A = 33 , T = 3 / 2 quartet and found to be inconsistent with the generally accepted quadratic form. peerReviewed
P776 Stress ecocardiography and speckle tracking analysis in patients with heart failure and preserved ejection fraction
2020
Abstract BACKGROUND Heart failure with preserved ejection fraction (HFpEF) is characterized by heart failure symptoms despite preserved LV systolic function together with at least one among left ventricle hypertrophy/left atrial enlargement plus diastolic dysfunction (DD) and increased brain natriuretic peptide levels. Rest echocardiography could still be normal despite patients experience HF symptoms. Speckle tracking analysis (STE) analyzes myocardial deformation and is able to identify subtle left ventricular dysfunction. PURPOSE to analyze the added value of stress echocardiography to improve diagnostic accuracy in patients with normal ejection fraction and unexplained dyspnoea by evalu…
A Monte Carlo-aided design of a modular 241Am-Be neutron irradiator
2013
Monte Carlo studies aimed at designing a modular 241Am-Be neutron irradiator for testing neutron detectors and personal dosimeters and processing large volume samples are reported in this study. The evaluation of the shapes and thicknesses of the moderator and shielding materials was carried out by a MCNP5 Monte Carlo simulation code. The reliability of the simulation was experimentally verified by the activation of gold foils and TLD dosimeter measurements in an irradiation cell placed at the center of the test configuration.