96 research outputs found

    π

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    We report on measurements of neutral pion production in the inclusive reactions d + C → π0 + x and d + Cu → π0 + x at an incident momentum of 4.5 GeV/c per nucleon. The experiments were performed on the LHE 90-channel lead glass γ-spectrometer. The cross sections were measured over the kinematical region specified by the inequalities θπ ≤ 16° and Eπ ≥ 2 GeV (in the laboratory frame). The cumulative number and transverse momentum dependencies of the exponent n in the invariant cross section parameterization Ed3 σ / d3 p ~ Atn are investigated by comparing of the observed cross sections for π0 production on carbon and copper targets in the intervals 0.6 ≤ X ≤ 1.8 and 0.04 ≤ pT2 ≤ 0.40 (GeV/c)2. The double differential cross section for the reaction d + C → π0 + x is measured using statistics of about 4.5 · 104π0 mesons. On the basis of these data we verified the so-called cluster mechanism of π0 production. We have compared our data for the reaction d + C → π0 + x, extrapolated to θπ = 0°, with the data from another experiments on π− production: d + C → π−(0°) + x (P = 1.75 and 2.88 GeV/c per nucleon) [1]; p + d → π−(180°) + x and p + d → π+(180°) + x (P = 8.9 GeV/c per nucleon) [2]; d + p → π−(0°) + x (P = 8.9 GeV/c per nucleon) [3]. The invariant cross sections were approximated by an exponential function Ed3 σ / d3 p ~ exp(−X / X0). The slope parameter X0 at different kinetic energies of the projectiles in the range of 1.05÷8.0 GeV per nucleon is determined

    Response of the ATLAS tile calorimeter prototype to muons

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    A study of high energy muons traversing the ATLAS hadron Tile calorimeter in the barrel region in the energy range between 10 and 300~GeV is presented. Both test beam experimental data and Monte Carlo simulations are given and show good agreement. The Tile calorimeter capability of detecting isolated muons over the above energy range is demonstrated. A signal to background ratio of about 10 is expected for the nominal LHC luminosity (1034cm2sec110^{34} cm^{-2} sec^{-1}). The photoelectron statistics effect in the muon shape response is shown. The e/mip ratio is found to be 0.81±0.03 0.81 \pm 0.03; the e/μ\mu ratio is in the range 0.91 - 0.97. The energy loss of a muon in the calorimeter, dominated by the energy lost in the absorber, can be correlated to the energy loss in the active material. This correlation allows one to correct on an event by event basis the muon energy loss in the calorimeter and therefore reduce the low energy tails in the muon momentum distribution

    Evaluation of Fermi Read-out of the ATLAS Tilecal Prototype

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    Prototypes of the \fermi{} system have been used to read out a prototype of the \atlas{} hadron calorimeter in a beam test at the CERN SPS. The \fermi{} read-out system, using a compressor and a 40 MHz sampling ADC, is compared to a standard charge integrating read-out by measuring the energy resolution of the calorimeter separately with the two systems on the same events. Signal processing techniques have been designed to optimize the treatment of \fermi{} data. The resulting energy resolution is better than the one obtained with the standard read-out

    A measurement of the energy loss spectrum of 150 GeV muons in iron

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    The energy loss spectrum of 150 GeV muons has been measured with a prototype of the ATLAS hadron calorimeter in the H8 beam of the CERN SPS.\\ The differential probability dP/dvdP/dv per radiation length of a fractional energy loss v=ΔEμ/Eμv = \Delta E_{\mu} / E_{\mu} has been measured in the range v=0.01÷0.95v = 0.01 \div 0.95 ; it is then compared with the theoretical predictions for energy losses due to bremsstrahlung and production of electron-positron pairs or of energetic knock-on electrons.\\ The integrated probability 0.010.95(dP/dv)dv\int_{0.01}^{0.95} (dP/dv) dv is (1.610±0.015stat.±0.105syst.)103(1.610\pm0.015_{stat.}\pm0.105_{syst.})\cdot10^{-3} in agreement with the theoretical predictions of 1.5561031.556\cdot10^{-3} and 1.6191031.619\cdot10^{-3}. %7.8.96 - start Agreement with theory is also found in two intervals of vv where production of electron-positron pairs and knock-on electrons dominates. In the region of bremsstrahlung dominance (v=0.12÷0.95v = 0.12\div0.95) the measured integrated probability (1.160±0.040stat±0.075syst)104(1.160\pm0.040_{stat}\pm0.075_{syst})\cdot 10^{-4} is in agreement with the theoretical value of 1.1851041.185 \cdot 10^{-4} , obtained using Petrukhin and Shestakov's \cite{PS} description of the bremsstrahlung process. The same result is about 3.6 standard deviations (defined as the quadratic sum of statistical and systematic errors) lower than the theoretical prediction of 1.472104 1.472\cdot 10^{-4}, obtained using Tsai's \cite{TS} description of bremsstrahlung

    Results from a combined test of an electromagnetic liquid argon calorimeter with a hadronic scintillating-tile calorimeter

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    The first combined test of an electromagnetic liquid argon accordion calorimeter and a hadronic scintillating-tile calorimeter was carried out at the CERN SPS. These devices are prototypes of the barrel calorimeter of the future ATLAS experiment at the LHC. The energy resolution of pions in the energy range from 20 to 300~GeV at an incident angle θ\theta of about 11^\circ is well-described by the expression \sigma/E = ((46.5 \pm 6.0)\%/\sqrt{E} +(1.2 \pm 0.3)\%) \oplus (3.2 \pm 0.4)~\mbox{GeV}/E. Shower profiles, shower leakage, and the angular resolution of hadronic showers were also studied

    ATLAS detector and physics performance: Technical Design Report, 1

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    Franny’s Jesus Prayer: J.D. Salinger and Orthodox Christian Spirituality

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    The Way of a Pilgrim and The Pilgrim Continues His Way—is a Russian hesychast text that was first published in 1881 and translated into English in 1931. It has gained popularity in the English-speaking world thanks to J.D. Salinger who mentions and re-narrates it in his stories “Franny” and “Zooey”. This reference has often been noted in both critical works on Salinger and studies dedicated to the book The Way of a Pilgrim. However, scholars have never actually attempted to fundamentally analyze the textual interconnections between Salinger’s stories and the hesychast work. In this article, the text of The Way of a Pilgrim is read within the framework of Salinger’s stories and is interpreted as being significant for his later texts. From the hesychast book Salinger borrows a number of images and presents its philosophy as a spiritual ideal. At the same time, he approaches it with a certain irony and exposes several pitfalls of incorrectly interpreting the Jesus prayer, as illustrated by Franny, one of Salinger’s characters. Having brought to light the nature of Franny’s mistakes and her peccant intention, Salinger reestablishes the hesychast ideal and connects it with Søren Kierkegaard’s principle of theistic existentialism
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