52 research outputs found
Low-mass GEM detector with radial zigzag readout strips for forward tracking at the EIC
We present design and construction of a large low-mass Triple-GEM detector
prototype for forward tracking at a future Electron-Ion Collider. In this
environment, multiple scattering of forward and backward tracks must be
minimized so that electron tracks can be cleanly matched to calorimeter
clusters and so that hadron tracks can efficiently seed RICH ring
reconstruction for particle identification. Consequently, the material budget
for the forward tracking detectors is critical. The construction of the
detector builds on the mechanical foil stretching and assembly technique
pioneered by CMS for the muon endcap GEM upgrade. As an innovation, this
detector implements drift and readout electrodes on thin large foils instead of
on PCBs. These foils get stretched mechanically together with three GEM foils
in a single stack. This reduces the radiation length of the total detector
material in the active area by a factor seven from over 4% to below 0.6%. It
also aims at improving the uniformity of drift and induction gap sizes across
the detector and consequently signal response uniformity. Thin outer frames
custom-made from carbon-fiber composite material take up the tension from the
stretched foil stack and provide detector rigidity while keeping the detector
mass low. The gas volume is closed with thin aluminized polyimide foils. The
trapezoidal detector covers an azimuthal angle of 30.1 degrees and a radius
from 8 cm to 90 cm. It is read out with radial zigzag strips with pitches of
1.37 mrad at the outer radius and 4.14 mrad at the inner radius that reduce the
number of required electronics channels and associated cost while maintaining
good spatial resolution. All front-end readout electronics is located away from
the active area at the outer radius of the trapezoid.Comment: 4 pages, 7 figures, submitted to conference record of 2017 IEEE
Nuclear Science Symposium, Atlanta, G
Global Analysis of Helicity Parton Densities and Their Uncertainties
We present a new analysis of the helicity parton distributions of the
nucleon. The analysis takes into account the available data from inclusive and
semi-inclusive polarized deep inelastic scattering, as well as from polarized
pp scattering at RHIC. For the first time, all theoretical calculations are
performed fully at next-to-leading order (NLO) of perturbative QCD, using a
method that allows to incorporate the NLO corrections in a very fast and
efficient way in the analysis. We find evidence for a rather small gluon
polarization in the nucleon, over a limited region of momentum fraction, and
for interesting flavor patterns in the polarized sea.Comment: 4 pages, 3 figure
Beiträge zur Geschichte des Landkreises Regensburg 42
Die Zeit danach - Erinnerungen an die Jahre 1945/46 in und um Regensbur
Opportunities for Drell-Yan Physics at RHIC
Drell-Yan (DY) physics gives the unique opportunity to study the parton structure of nucleons in an experimentally and theoretically clean way. With the availability of polarized proton-proton collisions and asymmetric d+Au collisions at the Relativistic Heavy Ion Collider (RHIC), we have the basic (and unique in the world) tools to address several fundamental questions in QCD, including the expected gluon saturation at low partonic momenta and the universality of transverse momentum dependent parton distribution functions. A Drell-Yan program at RHIC is tied closely to the core physics questions of a possible future electron-ion collider, eRHIC. The more than 80 participants of this workshop focused on recent progress in these areas by both theory and experiment, trying to address imminent questions for the near and mid-term future
Recommended from our members
Opportunities for Drell-Yan Physics at RHIC
Drell-Yan (DY) physics gives the unique opportunity to study the parton structure of nucleons in an experimentally and theoretically clean way. With the availability of polarized proton-proton collisions and asymmetric d+Au collisions at the Relativistic Heavy Ion Collider (RHIC), we have the basic (and unique in the world) tools to address several fundamental questions in QCD, including the expected gluon saturation at low partonic momenta and the universality of transverse momentum dependent parton distribution functions. A Drell-Yan program at RHIC is tied closely to the core physics questions of a possible future electron-ion collider, eRHIC. The more than 80 participants of this workshop focused on recent progress in these areas by both theory and experiment, trying to address imminent questions for the near and mid-term future
Recommended from our members
Opportunities for Polarized He-3 in RHIC and EIC
The workshop on opportunities for polarized He-3 in RHIC and EIC was targeted at finding practical ways of implementing and using polarized He-3 beams. Polarized He-3 beams will provide the unique opportunity for first measurements, i.e, to a full quark flavor separation measuring single spin asymmetries for p{sup +}, p{sup -} and p{sup 0} in hadron-hadron collisions. In electron ion collisions the combination of data recorded with polarized electron proton/He-3 beams allows to determine the quark flavor separated helicity and transverse momentum distributions. The workshop had sessions on polarized He-3 sources, the physics of colliding polarized He-3 beams, polarimetry, and beam acceleration in the AGS Booster, AGS, RHIC, and ELIC. The material presented at the workshop will allow making plans for the implementation of polarized He-3 beams in RHIC
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