16578177
An Apparatus to Measure the Structure of the Pion
Abstract We discuss the design and performance of a large-acceptance double-magnet spectrometer used in Fermilab Experiment 615. The apparatus was used to measure the properties of high-invariant-mass muon pairs produced in collisions of a pion beam with a tungsten target in order to infer the distribution of quarks within the pion and to study the production mechanism in detail. The emphasis was on interactions in which a single quark, and subsequently the muon pair, carried a large fraction of the pion's momentum. A hardware trigger processor enabled the detector to extract the relatively weak signal while operating in a high-rate environment.
19261126
Experimental study of muon pairs produced by 252-GeV pions on tungsten.
We present the results of a study of muon pairs with invariant masses greater than 4.05 GeV/c/sup 2/ produced in high-energy pion-nucleon interactions. The production cross section together with the inferred pion and nucleon structure functions are reported and compared with other experiments and with QCD predictions. The transverse-momentum distributions are also presented. Finally, the full angular distribution in costheta and phi is given as a function of mass, Feynman x, and transverse momentum. Longitudinal photon polarization is seen in the lower portion of the mass range at high x/sub ..pi../. This result is compared with a higher-twist model.
125981400
A Study of Photons from Decays of the K0(L)
20396173
Measurement of the ratio of sea to valence quarks in the nucleon.
The ratio of sea to valence quarks for nucleons in tungsten has been measured for the fractional momentum range 0.04{lt}{ital x}{sub {ital N}}{lt}0.36. The determination is based on the relative production rate of muon pairs by {pi}{sup +} and {pi}{sup {minus}} beams on a tungsten target. The results provide the most accurate determination to date of this ratio in the region {ital x}{sub {ital N}}{lt}0.1 and {ital Q}{sup 2}{gt}20 GeV{sup 2}, and are in good agreement with earlier measurements.
41404357
Longitudinal photon polarization in muon pair production at high xF.
Muon pair production by pions has been studied in an apparatus optimized for detection at large x-italic/sub F-italic/. Results, based on a small fraction of the data, are reported here for the virtual-photon polarization and the pion structure function. These results confirm our previous work and are consistent with a QCD model involving higher-twist effects at large x-italic/sub F-italic/.
117780445
Report of the Fixed-Target Proton-Accelerator Group
The fixed target proton accelerator group divided itself into two roughly equal parts. One sub-group concentrated on a high intensity (10/sup 14/ protons/sec) moderate energy (30 GeV) machine while the other worked on a moderate intensity (5 x 10/sup 11/ protons/sec) very high energy (20 TeV) machine. For experiments where the total available energy is adequate, the fixed target option added to a anti p p 20 TeV collider ring has several attractive features: (1) high luminosity afforded by intense beams striking thick solid targets; (2) secondary beams of hadrons, photons, and leptons; and (3) the versatility of a fixed target facility, where many experiments can be performed independently. The proposed experiments considered by the subgroup, including neutrino, photon, hadron, and very short lived particle beams were based both on scaled up versions of similar experiments proposed for Tevatron II at Fermilab and on the 400 GeV fixed target programs at Fermilab and CERN.
5386336
Material damage test for ILC collimators
Simulations were completed to determine the energy deposition of an ILC bunch using FLUKA,Geant4 and EGS4 to a set of different spoiler designs. These shower simulations were used as inputs to thermal and mechanical studies using ANSYS. This paper presents a proposal to optimise the material choice and mechanical design of ILC spoilers jaws using ATF and benchmark the energy deposition simulations and the ANSYS studies giving the researchers valuable data which will help achieve a definitive ILC spoiler design.
40350141
Status of the Next European Dipole (NED) activity of the Collaborated Accelerator Research in Europe (CARE) project
Plans for LHC upgrade and for the final focalization of linear colliders call for large aperture and/or high-performance dipole and quadrupole magnets that may be beyond the reach of conventional NbTi magnet technology. The Next European Dipole (NED) activity was launched on January 1st, 2004 to promote the development of high-performance, Nb/sub 3/Sn wires in collaboration with European industry (aiming at a noncopper critical current density of 1500 A/mm/sup 2/ at 4.2 K and 15 T) and to assess the suitability of Nb/sub 3/Sn technology to the next generation of accelerator magnets (aiming at an aperture of 88 mm and a conductor peak field of 15 T). It is integrated within the Collaborated Accelerator Research in Europe (CARE) project, involves seven collaborators, and is partly funded by the European Union. We present here an overview of the NED activity and we report on the status of the various work packages it encompasses.
6937475
Search for gravitational-wave bursts in LIGO data from the fourth science run
The fourth science run of the LIGO and GEO 600 gravitational-wave detectors, carried out in early 2005, collected data with significantly lower noise than previous science runs. We report on a search for short-duration gravitational-wave bursts with arbitrary waveform in the 64–1600 Hz frequency range appearing in all three LIGO interferometers. Signal consistency tests, data quality cuts and auxiliary-channel vetoes are applied to reduce the rate of spurious triggers. No gravitational-wave signals are detected in 15.5 days of live observation time; we set a frequentist upper limit of 0.15 day−1 (at 90% confidence level) on the rate of bursts with large enough amplitudes to be detected reliably. The amplitude sensitivity of the search, characterized using Monte Carlo simulations, is several times better than that of previous searches. We also provide rough estimates of the distances at which representative supernova and binary black hole merger signals could be detected with 50% efficiency by this analysis.