Two rare kaon decays: A primer

title: Longitudinal photon polarization in muon pair production at high xF.
abstract: 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/.

title: Report of the Fixed-Target Proton-Accelerator Group
abstract: 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.

title: 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.

title: Experimental study of muon pairs produced by 252-GeV pions on tungsten.
abstract: 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.

title: Measurement of the ratio of sea to valence quarks in the nucleon.
abstract: 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.

title: ILC Reference Design Report: ILC Global Design Effort and World Wide Study

title: Status of the Next European Dipole (NED) activity of the Collaborated Accelerator Research in Europe (CARE) project
abstract: 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.

title: Search for gravitational waves associated with 39 gamma-ray bursts using data from the second, third, and fourth LIGO runs
abstract: We present the results of a search for short-duration gravitational-wave bursts associated with 39 gamma-ray bursts (GRBs) detected by gamma-ray satellite experiments during LIGO’s S2, S3, and S4 science runs. The search involves calculating the crosscorrelation between two interferometer data streams surrounding the GRB trigger time. We search for associated gravitational radiation from single GRBs, and also apply statistical tests to search for a gravitational-wave signature associated with the whole sample. For the sample examined, we find no evidence for the association of gravitational radiation with GRBs, either on a single-GRB basis or on a statistical basis. Simulating gravitational-wave bursts with sine-Gaussian waveforms, we set upper limits on the root-sum-square of the gravitational-wave strain amplitude of such waveforms at the times of the GRB triggers. We also demonstrate how a sample of several GRBs can be used collectively to set constraints on population models. The small number of GRBs and the significant change in sensitivity of the detectors over the three runs, however, limits the usefulness of a population study for the S2, S3, and S4 runs. Finally, we discuss prospects for the search sensitivity for the ongoing S5 run, and beyond for the next generation of detectors.