1,018 research outputs found
Anomalous specific heat jump in the heavy fermion superconductor CeCoIn
We study the anomalously large specific heat jump and its systematic change
with pressure in CeCoIn superconductor. Starting with the general free
energy functional of the superconductor for a coupled electron boson system, we
derived the analytic result of the specific heat jump of the strong coupling
superconductivity occurring in the coupled electron boson system. Then using
the two component spin-fermion model we calculate the specific heat coefficient
both for the normal and superconducting states and show a good
agreement with the experiment of CeCoIn. Our result also clearly
demonstrated that the specific heat coefficient of a coupled electron
boson system can be freely interpreted as a renormalization either of the
electronic or of the bosonic degrees of freedom.Comment: 5 pages, 2 figure
Shadowing in photo-production : role of in-medium hadrons
We study the effects of in-medium hadronic properties on shadowing in
photon-nucleus interactions in Glauber model as well as in the multiple
scattering approach. A reasonable agreement with the experimental data is
obtained in a scenario of downward spectral shift of the hadrons. Shadowing is
found to be insensitive to the broadening of the spectral functions. An impact
parameter dependent analysis of shadowing might shed more light on the role of
in-medium properties of hadrons.Comment: Title modified; version to appear in PRC, Rapid Communication
A Field-theoretical Interpretation of the Holographic Renormalization Group
A quantum-field theoretical interpretation is given to the holographic RG
equation by relating it to a field-theoretical local RG equation which
determines how Weyl invariance is broken in a quantized field theory. Using
this approach we determine the relation between the holographic C theorem and
the C theorem in two-dimensional quantum field theory which relies on the
Zamolodchikov metric. Similarly we discuss how in four dimensions the
holographic C function is related to a conjectured field-theoretical C
function. The scheme dependence of the holographic RG due to the possible
presence of finite local counterterms is discussed in detail, as well as its
implications for the holographic C function. We also discuss issues special to
the situation when mass deformations are present. Furthermore we suggest that
the holographic RG equation may also be obtained from a bulk diffeomorphism
which reduces to a Weyl transformation on the boundary.Comment: 24 pages, LaTeX, no figures; references added, typos corrected,
paragraph added to section
Comparison of advanced gravitational-wave detectors
We compare two advanced designs for gravitational-wave antennas in terms of
their ability to detect two possible gravitational wave sources. Spherical,
resonant mass antennas and interferometers incorporating resonant sideband
extraction (RSE) were modeled using experimentally measurable parameters. The
signal-to-noise ratio of each detector for a binary neutron star system and a
rapidly rotating stellar core were calculated. For a range of plausible
parameters we found that the advanced LIGO interferometer incorporating RSE
gave higher signal-to-noise ratios than a spherical detector resonant at the
same frequency for both sources. Spheres were found to be sensitive to these
sources at distances beyond our galaxy. Interferometers were sensitive to these
sources at far enough distances that several events per year would be expected
The HERMES Dual-Radiator Ring Imaging Cerenkov Detector
The construction and use of a dual radiator Ring Imaging Cerenkov(RICH)
detector is described. This instrument was developed for the HERMES experiment
at DESY which emphasizes measurements of semi-inclusive deep-inelastic
scattering. It provides particle identification for pions, kaons, and protons
in the momentum range from 2 to 15 GeV, which is essential to these studies.
The instrument uses two radiators, C4F10, a heavy fluorocarbon gas, and a wall
of silica aerogel tiles. The use of aerogel in a RICH detector has only
recently become possible with the development of clear, large homogeneous and
hydrophobic aerogel. A lightweight mirror was constructed using a newly
perfected technique to make resin-coated carbon-fiber surfaces of optical
quality. The photon detector consists of 1934 photomultiplier tubes for each
detector half, held in a soft steel matrix to provide shielding against the
residual field of the main spectrometer magnet.Comment: 25 pages, 23 figure
Glomerular Autoimmune Multicomponents of Human Lupus Nephritis In Vivo (2): Planted Antigens.
Glomerular planted antigens (histones,DNA,andC1q) arepotential targets of autoimmunity in lupus nephritis (LN). However, the characterization of these antigens in human glomeruli in vivo remains inconsistent. We eluted glomerular autoantibodies recognizing planted antigens from laser-microdissected renal biopsy samples of 20 patientswith LN. Prevalent antibody isotypes were defined, levelswere determined, and glomerular colocalization was investigated. Renal and circulating antibodieswerematched, and serum levelswere compared in 104 patients with LN, 84 patients with SLE without LN, and 50 patients with rheumatoid arthritis (RA). Autoantibodies against podocyte antigens (antia-enolase/antiannexin AI) were also investigated. IgG2 autoantibodies against DNA, histones (H2A, H3, and H4), and C1q were detected in 50%, 55%, and 70% of biopsy samples, respectively. Anti-DNA IgG3 was the unique non-IgG2 anti-DNA deposit, and anti-C1q IgG4 was mainly detected in subepithelial membranous deposits. Anti-H3, anti-DNA, and anti-C1q IgG2 autoantibodies were also prevalent in LN serum, which also contained IgG3 against the antigen panel and anti-C1q IgG4. Serum and glomerular levels of autoantibodies were not strictly associated. High serum levels of all autoantibodies detected, including anti a-enolase and antiannexin AI, identified LN versus SLE and RA. Anti-H3 and antia-enolase IgG2 levels had the most remarkable increase in LN serum and represented a discriminating feature of LN in principal component analysis. The highest levels of these two autoantibodies were also associated with proteinuria.3.5 g/24 hours and creatinine>1.2 mg/dl. Our findings suggest that timely autoantibody characterization might allow outcome prediction and targeted therapies for patients with nephritis
The -dependence of the generalised Gerasimov-Drell-Hearn integral for the deuteron, proton and neutron
The Gerasimov-Drell-Hearn (GDH) sum rule connects the anomalous contribution
to the magnetic moment of the target nucleus with an energy-weighted integral
of the difference of the helicity-dependent photoabsorption cross sections. The
data collected by HERMES with a deuterium target are presented together with a
re-analysis of previous measurements on the proton. This provides a measurement
of the generalised GDH integral covering simultaneously the nucleon-resonance
and the deep inelastic scattering regions. The contribution of the
nucleon-resonance region is seen to decrease rapidly with increasing . The
DIS contribution is sizeable over the full measured range, even down to the
lowest measured . As expected, at higher the data are found to be in
agreement with previous measurements of the first moment of . From data on
the deuteron and proton, the GDH integral for the neutron has been derived and
the proton--neutron difference evaluated. This difference is found to satisfy
the fundamental Bjorken sum rule at GeV.Comment: 12 pages, 10 figure
Measurement of the Proton Spin Structure Function g1p with a Pure Hydrogen Target
A measurement of the proton spin structure function g1p(x,Q^2) in
deep-inelastic scattering is presented. The data were taken with the 27.6 GeV
longitudinally polarised positron beam at HERA incident on a longitudinally
polarised pure hydrogen gas target internal to the storage ring. The kinematic
range is 0.021<x<0.85 and 0.8 GeV^2<Q^2<20 GeV^2. The integral
Int_{0.021}^{0.85} g1p(x)dx evaluated at Q0^2 of 2.5 GeV^2 is
0.122+/-0.003(stat.)+/-0.010(syst.).Comment: 7 pages, 3 figures, 1 table, RevTeX late
Measurement of single-spin azimuthal asymmetries in semi-inclusive electroproduction of pions and kaons on a longitudinally polarised deuterium target
Single-spin asymmetries have been measured for semi-inclusive
electroproduction of , , and mesons in
deep-inelastic scattering off a longitudinally polarised deuterium target. The
asymmetries appear in the distribution of the hadrons in the azimuthal angle
around the virtual photon direction, relative to the lepton scattering
plane. The corresponding analysing powers in the moment of the
cross section are for ,
for ,
for and for . The moments are
compatible with zero for all particles.Comment: Revised version shortened 9 pages, 3 tables, 7 figure
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