433 research outputs found
Measurement of the - mixing angle in and beams with GAMS- Setup
The results of mixing angle measurement for , mesons generated
in charge exchange reactions with and beams are preseneted.
When the , mesons are described in nonstrange(NS)--strange(S)
quark basis the and beams allow to study and
parts of the meson wave function. The cross section ratio at
(GeV/c) in the beam is , results in mixing angle . For
beam the ratio is . It was found that
gluonium content in is . The
experiment was carried out with GAMS-4 Setup.Comment: 6 pages, 4 figures, 1 table, to be submitted in European physical
journal C. Minor changes, the Bibliography extende
Simulation educational technology «STANDARDIZED PATIENT» for teaching skills of clinical communication in the Medical University
The experience of teaching students of medical high school clinical communication skills using the simulation educational technology "standardized patient" is presented; тhe statistical data on the validity and reliability of the methods for assessing the communication skills of doctors are givenПредставлен опыт обучения студентов медицинского вуза навыкам клинического общения с помощью симуляционной образовательной технологии «стандартизированный пациент»; приведены статистические данные валидности и надежности методики оценки коммуникативных навыков враче
An Improved Limit on Invisible Decays of Positronium
The results of a new search for positronium decays into invisible final
states are reported. Convincing detection of this decay mode would be a strong
evid ence for new physics beyond the Standard Model (SM): for example the
existence of extra--dimensions, of milli-charged particles, of new light gauge
bosons or of mirror particles. Mirror matter could be a relevant dark matter
candidate.
In this paper the setup and the results of a new experiment are presented. In
a collected sample of about orthopositronium decay
s, no evidence for invisible decays in an energy window [0,80] keV was found
and an upper limit on the branching ratio of orthopositronium \invdecay could
be set: \binvdecay<4.2\times 10^{-7} (90% C.L.)
Our results provide a limit on the photon mirror-photon mixing strength
(90% C.L.) and rule out particles lighter
than the electron mass with a fraction of the
electron charge. Furthermore, upper limits on the branching ratios for the
decay of parapositronium (90%
C.L.) and the direct annihilation (90% C.L.) could be set.Comment: 17 pages, 7 figures, added references, fixed limit on millicharged
particles and changed two plots accordingl
Search for invisible decays of sub-GeV dark photons in missing-energy events at the CERN SPS
We report on a direct search for sub-GeV dark photons (A') which might be
produced in the reaction e^- Z \to e^- Z A' via kinetic mixing with photons by
100 GeV electrons incident on an active target in the NA64 experiment at the
CERN SPS. The A's would decay invisibly into dark matter particles resulting in
events with large missing energy. No evidence for such decays was found with
2.75\cdot 10^{9} electrons on target. We set new limits on the \gamma-A' mixing
strength and exclude the invisible A' with a mass < 100 MeV as an explanation
of the muon g_\mu-2 anomaly.Comment: 6 pages, 3 figures; Typos corrected, references adde
THE PRESENT STATE OF THE PROBLEM OF RICKETTSIOSES IN RUSSIA AND NEW APPROACHES TO THE CLASSIFICATION OF DISEASES CAUSED BY SPOTTED FEVER GROUP RICKETTSIAE
The paper presents analysis of the development and the current status of the doctrine about rickettsia and rickettsiosis. Progress in the study of Rickettsia is associated with, improved methods for their detection and isolation - using live biotechnological systems (cultivation in the experimental lines of ticks-sensitive lines of eukaryotic cells) in combination with methods of genotyping and. classical ricketsial methods. The development and. use of new methodological approaches to the study of tick-borne rickettsiae and other alpha-proteobacteria led to an important revision of ideas about genetic diversity, heterogeneity of antigenic and. biological characteristics, ecology and. contribution to the infectious pathology of various representatives of the order Rickettsiales in Russia
Test of an LED Monitoring System for the PHOS Spectrometer
Preprint submitted to Elsevier Print on 26th January 2000A prototype monitoring system for the Photon Spectrometer (PHOS) of the ALICE experiment at LHC is described in detail. The prototype consists of Control and Master modules. The first one is 8x8 matrix of Light Emitting Diodes coupled with stable generators of current pulses. The system provides an individual control for each of the 64 channels of PHOS prototype based on lead-tungstate crystals. A long term stability of order of 10-3 has been achieved in integral beam tests of the monitoring system and PHOS prototypes
- …