120272757
A System of Cylindrical Drift Chambers in a Superconducting Solenoid
Abstract A superconducting solenoid at the CERN ISR has been equipped with a system of high accuracy cylindrical drift chambers. This detector consists of eight layers of field shaped drift cells with a delay line opposite each sense wire to provide coupled two dimensional readout. The design, construction, and operation of this system are discussed. The resolution and performance of the delay lines and sense wires under ISR running conditions are shown.
121608159
Observation of high transverse momentum electrons at the CERN ISR
Abstract A search for high transverse momentum electrons directly produced in proton-proton collisions has been performed at the CERN ISR. The apparatus included a magnetic spectrometer with wire spark chambers, a lead-glass counter array, and a threshold gas Cerenkov counter. At a centre-of-mass energy √ s = 52.7 GeV, a signal has been observed in the range 1.6 T ∗ GeV /c . The signal occurs at a level of approximately 10 −4 of the inclusive pion cross-section.
120328133
Evidence for pomeron single-quark interactions in proton diffraction at the ISR
Abstract Measurements are presented of two exclusive diffractive reactions, pp → (Λ 0 φ 0 K + ) p and pp → (Λ 0 Λ 0 p)p , at √ s = 63 GeV . Pronounced correlations with the beam direction are observed (in the rest frame of the forward-going bracketed system) for those outgoing particles which contain the beam valence quarks. In each case there is a forward-Λ0 in correlation with a backward K+ or p, respectively. No such behavior is seen for the particles which do not contain beam valence quarks (φ 0 and Λ 0 , respectively) . Interpreted as examples of pomeron-proton scattering, these results constitute evidence that, for these final states, the pomeron interacts with a single valence quark and apparently back-scatters it. The subsequent hadronization leads to a longitudinal event structure.
118472339
A study of longitudinal polarization at LEP
120200157
Unusual production features of isoscalar mesons in proton diffractive dissociation at the CERN-ISR
Abstract D(1285) and E/iota(1422) are observed in the diffractive dissociation process, pp→(pK 0 K +- π ± )p, with √ s =63Gev. The D(1285) is produced with dominant ±1 helicity. Several unusual features of the data suggest that the mesonic states result from gluonic interactions in the collision.
122529613
A Measurement of Single Electrons, electron Pairs, and Associated Phenomena, in Proton Proton Collisions at the CERN ISR
Abstract Measurements of single-electron production in proton-proton collisions at the CERN ISR are presented for five centre-of-mass energies √s = 23.5, 30.6, 44.8, 52.7, and 62.4 GeV. The invariant cross sections for single electrons with transverse momenta of 0.60 to 4.7 GeV/c are given. Measurements of electron-positron pairs and measurements of charged hadrons produced in association with the single electrons, are also reported.
16404024
Star-planet interactions
Much effort has been invested in recent years, both observationally and theoretically, to understand the interacting processes taking place in planetary systems consisting of a hot Jupiter orbiting its star within 10 stellar radii. Several independent studies have converged on the same scenario: that a short‐period planet can induce activity on the photosphere and upper atmosphere of its host star. The growing body of evidence for such magnetic star‐planet interactions includes a diverse array of photometric, spectroscopic and spectropolarimetric studies. The nature of which is modeled to be strongly affected by both the stellar and planetary magnetic fields, possibly influencing the magnetic activity of both bodies, as well as affecting irradiation and non‐thermal and dynamical processes. Tidal interactions are responsible for the circularization of the planet orbit, for the synchronization of the planet rotation with the orbital period, and may also synchronize the outer convective envelope of the star ...
119270802
Spitzer Observations of the Thermal Emission from WASP-43b
WASP-43b is one of the closest-orbiting hot Jupiters, with a semimajor axis of a?= 0.01526?? 0.00018?AU and a period of only 0.81?days. However, it orbits one of the coolest stars with a hot Jupiter (T *?= 4520?? 120?K), giving the planet a modest equilibrium temperature of T eq?= 1440?? 40?K, assuming zero Bond albedo and uniform planetary energy redistribution. The eclipse depths and brightness temperatures from our jointly fit model are 0.347%?? 0.013% and 1670?? 23?K at 3.6 ?m and 0.382%?? 0.015% and 1514?? 25?K at 4.5 ?m. The eclipse timings improved the estimate of the orbital period, P, by a factor of three (P = 0.81347436 ? 1.4 ? 10?7 days) and put an upper limit on the eccentricity (). We use our Spitzer eclipse depths along with four previously reported ground-based photometric observations in the near-infrared to constrain the atmospheric properties of WASP-43b. The data rule out a strong thermal inversion in the dayside atmosphere of WASP-43b. Model atmospheres with no thermal inversions and fiducial oxygen-rich compositions are able to explain all the available data. However, a wide range of metallicities and C/O ratios can explain the data. The data suggest low day-night energy redistribution in the planet, consistent with previous studies, with a nominal upper limit of about 35% for the fraction of energy incident on the dayside that is redistributed to the nightside.
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 ∓).
62238242
Data stream handling in the LHCb experiment
This paper presents the event data handling in the LHCb experiment, starting from the acceptance of events by the software trigger farm to making the data available for offline reprocessing. In the data acquisition system, events accepted by the High Level Trigger farm are assembled into streams according to their type. Each stream will be written to disk as a 2 GB file for optimal storage and ease of reconstruction. Under nominal conditions about 2 such files will be produced per minute. The life cycle and state transitions of each file are managed by means of a dedicated database. These files must be copied to the tape storage and simultaneously be made available online to various calibration and monitoring tasks. Additionally, to initiate the start of the offline re-processing all file parameters must be propagated to the offline Grid data analysis system. This system has been designed for extreme robustness and reliability with redundancy in almost every component and supports various fail-over mechanisms. The software, hardware, and protocols designed for this purpose will be discussed in detail. Performance figures of data-challenges done in 2007 will be shown.
18104149
Galaxy Zoo 2: detailed morphological classifications for 304 122 galaxies from the Sloan Digital Sky Survey
We present the data release for Galaxy Zoo 2 (GZ2), a citizen science project with more than 16 million morphological classifications of 304 122 galaxies drawn from the Sloan Digital Sky Survey (SDSS). Morphology is a powerful probe for quantifying a galaxy's dynamical history; however, automatic classifications of morphology (either by computer analysis of images or by using other physical parameters as proxies) still have drawbacks when compared to visual inspection. The large number of images available in current surveys makes visual inspection of each galaxy impractical for individual astronomers. GZ2 uses classifications from volunteer citizen scientists to measure morphologies for all galaxies in the DR7 Legacy survey with mr > 17, in addition to deeper images from SDSS Stripe 82. While the original GZ2 project identified galaxies as early-types, late-types or mergers, GZ2 measures finer morphological features. These include bars, bulges and the shapes of edge-on disks, as well as quantifying the relative strengths of galactic bulges and spiral arms. This paper presents the full public data release for the project, including measures of accuracy and bias. The majority (≳90 per cent) of GZ2 classifications agree with those made by professional astronomers, especially for morphological T-types, strong bars and arm curvature. Both the raw and reduced data products can be obtained in electronic format at http://data.galaxyzoo.org.