22,126 research outputs found
X-Ray Scanner for Atlas Barrel TRT Modules
X-ray scanners for gain mapping of ATLAS Barrel Transition Radiation Tracker
(TRT) modules were developed at Hampton University for quality assurance
purposes. Gas gain variations for each straw of the TRT modules were used to
decide whether wires should be removed or restrung, and to evaluate overall
module quality.Comment: Conference proceeding in the XXIV Physics in Collisions Conference
(PIC04), Boston, USA, June 2004, 3 pages, LaTeX, 6 eps figures. MONP0
Notes from the 3rd Axion Strategy Meeting
In this note we briefly summarize the main future targets and strategies for
axion and general low energy particle physics identified in the "3rd axion
strategy meeting" held during the AXIONS 2010 workshop. This summary follows a
wide discussion with contributions from many of the workshop attendees.Comment: 5 pages, 1 figur
Quantum Entanglement in Top Quark Pair Production
Top quarks, the most massive particles in the standard model, attract
considerable attention since they decay before hadronizing. This presents
physicists with a unique opportunity to directly investigate their properties.
In this letter, we expand upon the work of G. Iskander, J. Pan, M. Tyler, C.
Weber and O. K. Baker to demonstrate that even with the most massive
fundamental particle, we see the same manifestation of entanglement observed in
both electroweak and electromagnetic interactions. We propose that the thermal
component resulting from protons colliding into two top quarks emerges from
entanglement within the two-proton wave function. The presence of entanglement
implies the coexistence of both thermal and hard scattering components in the
transverse momentum distribution. We use published ATLAS and CMS results to
show that the data exhibits the expected behavior.Comment: 10 pages, 5 figure
A slow mode wave as a possible source of Pi 2 and associated particle precipitation: a case study
International audienceAn intensification of auroral luminosity referred to as an auroral break-up often accompanies the onset of geomagnetic pulsation (Pi 2) at the dip-equator. One such auroral break-up occurred at 2239 UT on 16 June, 1986, being accompanied by weak substorm activity (AE~50 nT) which was recorded in all-sky image of Syowa Station, Antarctica (66.2°S, 71.8°E in geomagnetic coordinates). The associated Pi 2 magnetic pulsation was detected by a fluxgate magnetometer in the afternoon sector at the dip-equator (Huancayo, Peru; 1.44°N, 355.9° in geomagnetic coordinates; 12.1°S, 75.2°W in geographic coordinates; L=1.00). In spite of the large separation of the two stations in longitude and latitude, the auroral break-up and subsequent luminosity modulation were seen to be correlated with the wave form of the ground Pi 2 pulsation. This occurred in such a way that the luminosity maximum was seen to occur at the phase of maximum amplitudes of Pi 2 wave form. We argue that the observed correlation could be interpreted as indicating a Pi 2-modulation of a field-aligned acceleration of the low energy electrons that may occur near the equator of the midnight magnetosphere
Simulacija porarizacijskih mjerenja u elektrotvorbi kaona Monte Carlo metodom
Kaon electro-production experiments with polarized electron beam are planed at the Thomas Jefferson National Accelerator Facility (Virginia, USA) in order to complete the information on polarization response functions for the kaon electro-production reactions. The experiment uses the self analyzing property of the Λ recoil. The scattered electrons will be detected in coincidence with the kaons and the decay protons. This paper presents the simulation of this experiment which takes into account the spectrometer acceptances, multiple scattering and radiative corrections. The phase space distribution of the decay protons in the Λ center-of-mass system are generated in order to extract information on the polarization on the three directions. An experimental test with an unpolarized beam has been performed to estimate the efficiency of the method.U Thomas Jefferson National Accelerator Facility (Virginia, USA) predlažu se mjerenja elektrotvorbi s polariziranim elektronima radi cjelovitosti podataka o polarizacijskim funkcijama odziva u elektrotvorbi kaona. Mjerenje rabi samoanalizacijsko svojstvo odboja Λ čestice. Raspršeni elektroni opažat će se sudesno s kaonima i protonima. Ovaj rad predstavlja simulaciju tog eksperimenta u kojoj se uzimaju u obzir prihvati spektrometara, višestruko raspršenje i radijativne popravke. Izvodi se fazna raspodjela protona u centru mase Λ čestice radi dobivanja podataka o polarizaciji u trima smjerovima. Mjerenjem pomoću nepolariziranog snopa ocijenili smo učinkovitost metode
- …