[Show abstract][Hide abstract] ABSTRACT: The 1000 Genomes Project set out to provide a comprehensive description of common human genetic variation by applying whole-genome sequencing to a diverse set of individuals from multiple populations. Here we report completion of the project, having reconstructed the genomes of 2,504 individuals from 26 populations using a combination of low-coverage whole-genome sequencing, deep exome sequencing, and dense microarray genotyping. We characterized a broad spectrum of genetic variation, in total over 88 million variants (84.7 million single nucleotide polymorphisms (SNPs), 3.6 million short insertions/deletions (indels), and 60,000 structural variants), all phased onto high-quality haplotypes. This resource includes >99% of SNP variants with a frequency of >1% for a variety of ancestries. We describe the distribution of genetic variation across the global sample, and discuss the implications for common disease studies.
[Show abstract][Hide abstract] ABSTRACT: The focus of this report is on the opportunities enabled by the combination
of LSST, Euclid and WFIRST, the optical surveys that will be an essential part
of the next decade's astronomy. The sum of these surveys has the potential to
be significantly greater than the contributions of the individual parts. As is
detailed in this report, the combination of these surveys should give us
multi-wavelength high-resolution images of galaxies and broadband data covering
much of the stellar energy spectrum. These stellar and galactic data have the
potential of yielding new insights into topics ranging from the formation
history of the Milky Way to the mass of the neutrino. However, enabling the
astronomy community to fully exploit this multi-instrument data set is a
challenging technical task: for much of the science, we will need to combine
the photometry across multiple wavelengths with varying spectral and spatial
resolution. We identify some of the key science enabled by the combined surveys
and the key technical challenges in achieving the synergies.
[Show abstract][Hide abstract] ABSTRACT: A tightly focused beam on target is required in the muon collider/neutrino factory study. Specifically, up to 16 TP (1 TP = 10 12 protons) per pulse of a 24 GeV proton beam are to be delivered on target, with a pulse length of a few microseconds and a beam spot of 0.5 mm rms sigma. Experiment E951 at BNL was set up to explore the potential of various target materials. Optimization of the pion production led to the consideration of low-Z materials as potential targets. Thus, in the first phase of the E951 experiment, graphite and carbon-carbon composite targets were exposed to the AGS beam and their response to the induced thermal shock was studied. This paper presents theoretical prediction results as well as experimental results and makes an assessment of the abilities of prediction models to capture the dynamic response of the solid target. 1.
[Show abstract][Hide abstract] ABSTRACT: The LSST camera, which will be the largest digital camera built to date,
presents a number of novel challenges. The field of view will be 3.5
degrees in diameter and will be sampled by a 3.2 billion pixel array of
sensors to be read-out in under 2 seconds, which leads to demanding
constraints on the sensor architecture and read-out electronics. The
camera also incorporates three large refractive lenses, an array of five
wide-band large filters mounted on a carousel, and a mechanical shutter.
Given the fast optical beam (f/1.2) and tight tolerances for image
quality and throughput specifications, the requirements on the optical
design, assembly and alignment, and contamination control of the optical
elements and focal plane are crucial. We present an overview of the LSST
camera, with an emphasis on models of camera image quality and
throughput performance that are characterized by various analysis
packages and design considerations.
[Show abstract][Hide abstract] ABSTRACT: The Muon Ionization Cooling Experiment (MICE) is a strategic R&D project
intended to demonstrate the only practical solution to providing high
brilliance beams necessary for a neutrino factory or muon collider. MICE is
under development at the Rutherford Appleton Laboratory (RAL) in the United
Kingdom. It comprises a dedicated beamline to generate a range of input muon
emittances and momenta, with time-of-flight and Cherenkov detectors to ensure a
pure muon beam. The emittance of the incoming beam will be measured in the
upstream magnetic spectrometer with a scintillating fiber tracker. A cooling
cell will then follow, alternating energy loss in Liquid Hydrogen (LH2)
absorbers to RF cavity acceleration. A second spectrometer, identical to the
first, and a second muon identification system will measure the outgoing
emittance. In the 2010 run at RAL the muon beamline and most detectors were
fully commissioned and a first measurement of the emittance of the muon beam
with particle physics (time-of-flight) detectors was performed. The analysis of
these data was recently completed and is discussed in this paper. Future steps
for MICE, where beam emittance and emittance reduction (cooling) are to be
measured with greater accuracy, are also presented.
[Show abstract][Hide abstract] ABSTRACT: Limits on the anomalous WWγ and WWZ couplings are presented from a simultaneous fit to the data samples of three gauge boson pair final states in pp̅ collisions at √s=1.8TeV: Wγ production with the W boson decaying to eν or μν, W boson pair production with both of the W bosons decaying to eν or μν, and WW or WZ production with one W boson decaying to eν and the other W boson or the Z boson decaying to two jets. Assuming identical WWγ and WWZ couplings, 95% C.L. limits on the anomalous couplings of -0.30<Δκ<0.43 (λ=0) and -0.20<λ<0.20 (Δκ=0) are obtained using a form factor scale Λ=2.0TeV. Limits found under other assumptions on the relationship between the WWγ and WWZ couplings are also presented.
[Show abstract][Hide abstract] ABSTRACT: The LSST design is driven by four science themes and desire to engage
broad science community and general public in LSST data exploration. The
current baseline design, with an 8.4m (6.7m effective) primary mirror
and a 9.6 sq.deg. field of view, will allow about 10,000 square degrees
of sky to be visited twice per night, with an effective depth of r=24.5
per visit, every three nights. The system is designed to yield high
image quality as well as superb astrometric and photometric accuracy,
and will regularly produce three classes of data products. Level 1 data
products are generated continuously every observing night, including
alerts to objects that have changed flux or position, that will be
released within 60 seconds. Level 2 data products will be made available
as annual Data Releases and will include images and measurements of
positions, fluxes, and shapes, as well as variability information such
as orbital parameters for moving objects. The LSST Data Management
System will also facilitate the creation of Level 3 data products by
science teams external to the project by providing suitable Applications
Programming Interfaces (APIs), about 50 teraflops of user-dedicated
processing capability and 12 petabytes of user-dedicated storage. The
key aspect of these capabilities is that they will reside "next to" the
LSST data, avoiding the latency associated with downloads.
[Show abstract][Hide abstract] ABSTRACT: The Large Synoptic Survey Telescope is a large aperture, wide-field, ground-based telescope that will survey half the sky every few nights in six visible bands. The etendue of the LSST system (an optical measure of the information gathering capability) is over 320 m2/deg2 and is far greater than any other telescope. The LSST system provides an end-to-end astronomical survey facility to acquire process, analyze, catalog, and preserve the world's largest database of optical astronomical data. LSST will also open the time domain for studies of transient and moving objects. Multiple Data Access Centers will be strategically located to provide the user community with high-speed, open access to the many Petabytes of new information generated each year of the planned ten year survey. Scheduled to have first telescope light in early 2014, the LSST Observatory will be sited atop Cerro Pachón in Northern Chile. All three of the large mirrors required for the LSST are currently in production.
[Show abstract][Hide abstract] ABSTRACT: We study the flavor-changing-neutral-current process c-->u micro(+) micro(-) using 1.3 fb(-1) of pp[over ] collisions at square root s = 1.96 TeV recorded by the D0 detector operating at the Fermilab Tevatron Collider. We see clear indications of the charged-current mediated D(s)(+) and D(+)-->phipi(+) --> micro(+)micro(-)pi(+) final states with significance greater than 4 standard deviations above background for the D(+) state. We search for the continuum neutral-current decay of D(+)-->pi(+) micro(+) micro(-) in the dimuon invariant mass spectrum away from the phi resonance. We see no evidence of signal above background and set a limit of B(D(+) --> pi(+) micro(+) micro(-))<3.9 x 10(-6) at the 90% C.L. This limit places the most stringent constraint on new phenomena in the c--> u micro(+) micro(-) transition.
[Show abstract][Hide abstract] ABSTRACT: The plasma lens concept is examined as an alternative to focusing horns and solenoids for a neutrino beam facility. The concept is based on a combined high-current lens/target configuration. Current is fed at an electrode located downstream from the beginning of the target where pion capturing is needed. The current is carried by plasma outside the target. A second plasma lens section, with an additional current feed, follows the target. The plasma is immersed in a solenoidal magnetic field to facilitate its current profile shaping to optimize pion capture. Simulations of the not yet fully optimized configuration yielded a 25% higher neutrino flux at a detector situated at 3 km from the target than the horn system for the entire enegry spectrum and a factor of 2.47 higher flux for neutrinos with energy larger than 3 GeV. A major advantage of plasma lenses is in background reduction. In anti-neutrino operation, neutrino background is reduced by a factor of close to 3 for the whole spectrum, and for and for energy larger than 3 GeV; neutrino background is reduced by a factor of 3.6. Plasma lens advantages are due to: larger axial currents, high signal purity: minimal neutrino background in anti-neutrino runs. Additionally the lens medium consists of plasma, consequently, particle absorption and scattering is negligible. Withstanding high mechanical and thermal stresses in a plasma is not an issue.