115904384
Review of Lepton Production in Hadron-Hadron Collisions
The production of leptons, especially at values of transverse momentum well above 1 fermi−1, is a sensitive probe of hadron structure at small distances. In these lectures I hope to summarize in an informal manner the present knowledge of hadronically-produced leptons, with emphasis on the general features of the data, rather than on details of individual experiments. The reader is referred to the many recent reviews1–3) of the subject (some still in press at this time) for other points of view. I have borrowed freely from them, and gladly acknowledge the authors. Also, some aspects of the subject were discussed by Professor Min Chen in his lecture at this School, and are not repeated here.
123932176
Particle Production by 2.9-BeV Protons Incident on Beryllium and Platinum
118694154
Production of Dimuons by Pions and Protons at Fermilab
In this lecture I shall describe an experiment in progress1 at the Fermi National Accelerator Laboratory (FNAL) to study the production of μ+μ− pairs in hadron-hadron collisions. So far, we have used beams of 225 — GeV π+, π− and protons incident on carbon and tin targets for most of the data. In an earlier run, a 150 GeV positive beam was used with a beryllium target. The results I report of the 150 GeV run are final; those at 225 GeV are preliminary.
119595431
A wire-spark-chamber system with on-line computers
Abstract We describe the performance of a system of wire spark chambers and 2 on-line computers (one being time-shared) used in an experiment at the Brookhaven A.G.S. to study the decay of K± mesons via the τ mode (K±→ π ± π ± π ∓).
62560089
DIRAC: reliable data management for LHCb
DIRAC, LHCb's Grid Workload and Data Management System, utilizes WLCG resources and middleware components to perform distributed computing tasks satisfying LHCb's Computing Model. The Data Management System (DMS) handles data transfer and data access within LHCb. Its scope ranges from the output of the LHCb Online system to Grid-enabled storage for all data types. It supports metadata for these files in replica and bookkeeping catalogues, allowing dataset selection and localization. The DMS controls the movement of files in a redundant fashion whilst providing utilities for accessing all metadata. To do these tasks effectively the DMS requires complete self integrity between its components and external physical storage. The DMS provides highly redundant management of all LHCb data to leverage available storage resources and to manage transient errors in underlying services. It provides data driven and reliable distribution of files as well as reliable job output upload, utilizing VO Boxes at LHCb Tier1 sites to prevent data loss. This paper presents several examples of mechanisms implemented in the DMS to increase reliability, availability and integrity, highlighting successful design choices and limitations discovered.
123901120
A Study of Inclusive Spectra and Two Particle Correlations at Large Transverse Momentum
Abstract The inclusive production of π and η mesons at 90° from proton-proton collisions has been measured at the CERN ISR at centre-of-mass energies between 23.5 and 62.4 GeV. The momentum correlation of charged particles emitted together with a large transverse momentum pion has also been studied, using two magnetic spectrometers each centred at 90°.
116999427
A search for large transverse momentum electrons at the CERN ISR
At √s = 52.7 GeV, no electron events were observed for E > 7.0 GeV where one observed event corresponds to d2 σ/dE dω = 4 × 10−36 cm2/(srGeV). The observed events for 2.3 < E < 7.0 GeV are consistent with background. Upper limits to d2 σ/dE dω are given, and their relevance to the production of massive mesons is discussed.
27456469
Planet Hunters: A Transiting Circumbinary Planet in a Quadruple Star System
We report the discovery and confirmation of a transiting circumbinary planet (PH1b) around KIC 4862625, an eclipsing binary in the Kepler field. The planet was discovered by volunteers searching the first six Quarters of publicly available Kepler data as part of the Planet Hunters citizen science project. Transits of the planet across the larger and brighter of the eclipsing stars are detectable by visual inspection every ~137 days, with seven transits identified in Quarters 1-11. The physical and orbital parameters of both the host stars and planet were obtained via a photometric-dynamical model, simultaneously fitting both the measured radial velocities and the Kepler light curve of KIC 4862625. The 6.18 ± 0.17 R_⊕ planet orbits outside the 20 day orbit of an eclipsing binary consisting of an F dwarf (1.734 ± 0.044 R_☉, 1.528 ± 0.087 M_☉) and M dwarf (0.378 ± 0.023 R_☉, 0.408 ± 0.024 M_☉). For the planet, we find an upper mass limit of 169 M_⊕ (0.531 Jupiter masses) at the 99.7% confidence level. With a radius and mass less than that of Jupiter, PH1b is well within the planetary regime. Outside the planet's orbit, at ~1000 AU, a previously unknown visual binary has been identified that is likely bound to the planetary system, making this the first known case of a quadruple star system with a transiting planet.
119204101
Small-scale structure of the interstellar medium towards rho Oph stars: diffuse band observations
We present an investigation of small-scale-structure in the distribution of large molecules/dust in the interstellar medium through observations of diffuse interstellar bands (DIBs). High signal-to-noise optical spectra were recorded towards the stars rho Oph A, B, C and DE using the University College London Echelle Spectrograph (UCLES) on the Anglo-Australian Telescope. The strengths of some of the DIBs are found to differ by about 5-9 % between the close binary stars rho Oph A and B, which are separated by a projected distance on the sky of only ~344 AU. This is the first star-system in which such small-scale DIB strength variations have been reported. The observed variations are attributed to differences between a combination of carrier abundance and the physical conditions present along each sightline. The sightline towards rho Oph C contains relatively dense, molecule-rich material and has the strongest \lambda\lambda 5850 and 4726 DIBs. The gas towards DE is more diffuse and is found to exhibit weak C_2 (blue) DIBs and strong yellow/red DIBs. The differences in diffuse band strengths between lines of sight are, in some cases, significantly greater in magnitude than the corresponding variations among atomic and diatomic species, indicating that the DIBs can be sensitive tracers of interstellar cloud conditions.