64 research outputs found
Hard Probes in Heavy Ion Collisions at the LHC: Jet Physics
We discuss the importance of high-pT hadron and jet measurements in
nucleus-nucleus collisions at the CERN Large Hadron Collider.Comment: The writeup of the working group "Jet Physics" for the CERN Yellow
Report on "Hard Probes in Heavy Ion Collisions at the LHC", 123 pages.
Subgroup convenors: R. Baier, X.N. Wang, U.A. Wiedemann (theory) and I.P.
Lokhtin, A. Morsch (experiment). Editor: U.A. Wiedeman
Merging Galaxies in the SDSS EDR
We present a new catalog of merging galaxies obtained through an automated
systematic search routine. The 1479 new pairs of merging galaxies were found in
approximately 462 sq deg of the Sloan Digital Sky Survey Early Data Release
(SDSS EDR; Stoughton et al. 2002) photometric data, and the pair catalog is
complete for galaxies in the magnitude range 16.0 <= g* <= 20.
The selection algorithm, implementing a variation on the original
Karachentsev (1972) criteria, proved to be very efficient and fast. Merging
galaxies were selected such that the inter-galaxy separations were less than
the sum of the component galaxies' radii.
We discuss the characteristics of the sample in terms of completeness, pair
separation, and the Holmberg effect. We also present an online atlas of images
for the SDSS EDR pairs obtained using the corrected frames from the SDSS EDR
database. The atlas images also include the relevant data for each pair member.
This catalog will be useful for conducting studies of the general
characteristics of merging galaxies, their environments, and their component
galaxies. The redshifts for a subset of the interacting and merging galaxies
and the distribution of angular sizes for these systems indicate the SDSS
provides a much deeper sample than almost any other wide-area catalog to date.Comment: 58 pages, which includes 15 figures and 6 tables. Figures 2, 8, 9,
10, 11, 13, and 14 are provided as JPEG files. For online atlas, see
http://home.fnal.gov/~sallam/MergePair/ . Accepted for publication in A
First results from NA60 on low mass muon pair production in In-In collisions at 158 GeV/nucleon
The NA60 experiment at the CERN SPS studies dimuon production in
proton-nucleus and nucleus-nucleus collisions. The combined information from a
novel vertex telescope made of radiation-tolerant silicon pixel detectors and
from the muon spectrometer previously used in NA50 allows for a precise
measurement of the muon vertex and a much improved dimuon mass resolution. We
report on first results from the data taken for Indium-Indium collisions at 158
AGeV/nucleon in 2003, concentrating on a subsample of about 370 000 muon pairs
in the mass range GeV/. The light vector mesons and
are completely resolved, with a mass resolution of about 23 MeV/
at the . The transverse momentum spectra of the are measured over
the continuous range GeV/c; the inverse slope parameter of
the spectra is found to increase with centrality, with an average value of
MeV.Comment: 9 pages, 6 figures. Plenary talk, SQM2004 conference, Cape Town,
South Africa 15-20 September, 2004. To be published in Journal of Physics G:
Nuclear and Particle Physic
Letter of intent: study of dimuon and charm production with proton and heavy ion beams at the CERN SPS
Dark matter with invisible light from heavy double charged leptons of almost-commutative geometry?
A new candidate of cold dark matter arises by a novel elementary particle
model: the almostcommutative AC-geometrical framework. Two heavy leptons are
added to the Standard Model, each one sharing a double opposite electric charge
and an own lepton flavor number The novel mathematical theory of
almost-commutative geometry [1] wishes to unify gauge models with gravity. In
this scenario two new heavy (m_L>100GeV), oppositely double charged leptons
(A,C),(A with charge -2 and C with charge +2), are born with no twin quark
companions. The model naturally involves a new U(1) gauge interaction,
possessed only by the AC-leptons and providing a Coulomblike attraction between
them. AC-leptons posses electro-magnetic as well as Z-boson interaction and,
according to the charge chosen for the new U(1) gauge interaction, a new
"invisible light" interaction. Their final cosmic relics are bounded into
"neutral" stable atoms (AC) forming the mysterious cold dark matter, in the
spirit of the Glashow's Sinister model. An (AC) state is reached in the early
Universe along a tail of a few secondary frozen exotic components. They should
be now here somehow hidden in the surrounding matter. The two main secondary
manifest relics are C (mostly hidden in a neutral (Cee) "anomalous helium"
atom, at a 10-8 ratio) and a corresponding "ion" A bounded with an ordinary
helium ion (4He); indeed the positive helium ions are able to attract and
capture the free A fixing them into a neutral relic cage that has nuclear
interaction (4HeA).Comment: This paper has been merged with [astro-ph/0603187] for publication in
Classical and Quantum Gravit
Protective effects of hydrogen enriched saline on liver ischemia reperfusion injury by reducing oxidative stress and HMGB1 release
Oxidation of HMGB1 Causes Attenuation of Its Pro-Inflammatory Activity and Occurs during Liver Ischemia and Reperfusion
High mobility group box 1 (HMGB1) is a nuclear transcription factor. Once HMGB1 is released by damaged cells or activated immune cells, it acts as danger molecule and triggers the inflammatory signaling cascade. Currently, evidence is accumulating that posttranslational modifications such as oxidation may modulate the pro-inflammatory potential of danger signals. We hypothesized that oxidation of HMGB1 may reduce its pro-inflammatory potential and could take place during prolonged ischemia and upon reperfusion
Study of prompt dimuon and charm production with proton and heavy ion beams at the CERN SPS
NA6
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
Detection of mild papilloedema in posterior uveitis using spectral domain optical coherence tomography
Objective To compare two methods for diagnosing mild papilloedema (PO) using peripapillary total retinal (PTR) and retinal nerve fibre layer (RNFL) thickness measurement by spectral domain optical coherence tomography (OCT) in patients suffering from posterior uveitis. Methods 17 eyes in 17 patients with PO caused by posterior uveitis, 15 eyes in 15 patients with uveitis but with no PO based on slit lamp analysis were studied. High-quality OCT fundus images were analysed and graded by three masked observers using the Modified Frisen Scale. Eyes with PO were divided into two subgroups: mild (n= 15) and moderate-severe PO (n= 2). Two measurement methods were evaluated and compared: RNFL and PTR thickness measurements centred on the optic disc. Thickness values were calculated overall and for each quadrant and compared between groups. The main outcome measures were RNFL and PTR thickness, and thickness variation between control and affected patients for both protocols. Results Average RNFL and PTR thickness in the moderate-severe PO, mild PO and control groups were 274.5 +/- 54.45 mm, 134 +/- 31.69 mm, 97.4 +/- 14.43 mm and 722.25 +/- 29.34 mm, 437.53 +/- 84.47 mm, 327.8 +/- 25.92 mm, respectively. Mild PO differed from the control groups according to both the RNLF (p= 0.0006) and the PTR (p= 0.0002) measurements. The average thickness variation between control and mild PO was significantly different between RNFL and PTR measurements: 36.6 mm vs 109.73 mm (p< 0.0001), respectively. Conclusions PTR thickness measurement increases the sensitivity of detection of mild PO and could be useful for diagnosing and monitoring papillitis. A new protocol should be developed to measure PTR in the same 3.5 mm disc as the RNFL measurement
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