242 research outputs found
Leptogenesis from Heavy Right-Handed Neutrinos in CPT Violating Backgrounds
We discuss leptogenesis in a model with heavy right-handed Majorana neutrinos
propagating in a constant but otherwise generic CPT-violating axial time-like
background (which could be motivated by string theory considerations). At
temperatures much higher than the temperature of the electroweak phase
transition we solve analytically but approximately (using Pade approximants)
the corresponding Boltzmann equations, which describe lepton asymmetry
generation due to the tree-level decays of the heavy neutrinos into standard
model leptons. These leptons are effectively massless at such temperatures. The
current work completes in a rigorous way a preliminary treatment of the same
system, by some of the present authors. In this earlier work, lepton asymmetry
was crudely estimated considering the decay of a right-handed neutrino at rest.
Our present analysis includes thermal momentum modes for the heavy neutrino and
this leads to a total lepton asymmetry which is bigger by a factor of two as
compared to the previous estimate. Nevertheless, our current and preliminary
results for the freezeout are found to be in agreement (within a 12.5%
uncertainty). Our analysis depends on a novel use of Pade approximants to solve
the Boltzmann equations and may be more widely useful in cosmology.Comment: 33 pages latex, two figures incorporated; text overlap with
arXive:1412.707
The role of temperature dependent string-inspired CPT violating backgrounds in leptogenesis and the chiral magnetic effect
In a temperature dependent CPT-Violating (CPTV) axial time-like background
(induced by the Kalb-Ramond tensor field of string theory) we discuss
leptogenesis by solving the Boltzmann equation.The current work non-trivially
modifies the framework of a previous phenomenological approach by the authors
where the CPTV axial background was considered to be a constant (with no
microscopic justification). The constant background approximation though is
shown to capture the main phenomenological features of leptogenesis. On
comparing our analysis to the related chiral magnetic effect for axial current
condensates, we conclude that the Kalb-Ramond field does not play the role of
the chiral chemical potential needed for that effect.Comment: 17 pages revte
Great Lakes Regional Pollution Prevention Roundtable / Region 7 Conference [Welcome]
Welcome and short overview of Indiana Department of Environmental Management's pollution prevention initiatives.Ope
A Readout System for the STAR Time Projection Chamber
We describe the readout electronics for the STAR Time Projection Chamber. The
system is made up of 136,608 channels of waveform digitizer, each sampling 512
time samples at 6-12 Mega-samples per second. The noise level is about 1000
electrons, and the dynamic range is 800:1, allowing for good energy loss
() measurement for particles with energy losses up to 40 times minimum
ionizing. The system is functioning well, with more than 99% of the channels
working within specifications.Comment: 22 pages + 8 separate figures; 2 figures are .jpg photos to appear in
Nuclear Instruments and Method
Recommended from our members
Results from the STAR TPC system test
A system test of various components of the Solenoidal Tracker at RHIC (STAR) detector, operating in concern, has recently come on-line. Communication between a major sub-detector, a sector of the Time Projection Chamber (TPC), and the trigger, data acquisition and slow controls systems has been established, enabling data from cosmic ray muons to be collected. First results from an analysis of the TPC data are presented. These include measurements of system noise, electronic parameters such as amplifier gains and pedestal values, and tracking resolution for cosmic ray muons and laser induced ionization tracks. A discussion on the experience gained in integrating the different components for the system test is also given
Tofacitinib, an oral janus kinase inhibitor: pooled efficacy and safety analyses in an Australian rheumatoid arthritis population
In Australia, there is an unmet need for improved treatments for rheumatoid arthritis (RA). Tofacitinib is an oral Janus kinase inhibitor for the treatment of RA. To provide an overview of key study outcomes for tofacitinib in Australian patients, we analyzed the efficacy and safety of tofacitinib in the Australian subpopulation of global RA phase III and long-term extension (LTE) studies.
Data were pooled from the Australian subpopulation of four phase III studies and one LTE study (database not locked at cut-off date: January 2016). Patients in the phase III studies received tofacitinib 5 or 10 mg twice daily (BID), placebo (advancing to tofacitinib at months 3 or 6), or adalimumab, with background methotrexate or conventional synthetic disease-modifying antirheumatic drugs. Patients in the LTE study received tofacitinib 5 or 10 mg BID. Efficacy endpoints were American College of Rheumatology (ACR) 20/50/70 response rates, and change from baseline in the Disease Activity Score in 28 joints, erythrocyte sedimentation rate [DAS28-4(ESR)] and Health Assessment Questionnaire-Disability Index (HAQ-DI) scores. Safety endpoints included incidence of adverse events (AEs), serious AEs, and discontinuations due to AEs. AEs of special interest and laboratory parameters were analyzed in the LTE study.
Across phase III studies (N = 100), ACR response rates and improvements in DAS28-4(ESR) and HAQ-DI scores were numerically greater with tofacitinib vs. placebo at month 3, and increased until month 12. The results were sustained in the LTE study (N = 99) after 60 months' observation. In general, the efficacy and safety profiles of tofacitinib were similar to those of the global RA population.
In Australian patients with RA, tofacitinib therapy demonstrated sustained efficacy and consistent safety over ae 60 months' treatment.
Pfizer Inc.
NCT00960440; NCT00847613; NCT00856544; NCT00853385; NCT00413699
The STAR Time Projection Chamber: A Unique Tool for Studying High Multiplicity Events at RHIC
The STAR Time Projection Chamber (TPC) is used to record collisions at the
Relativistic Heavy Ion Collider (RHIC). The TPC is the central element in a
suite of detectors that surrounds the interaction vertex. The TPC provides
complete coverage around the beam-line, and provides complete tracking for
charged particles within +- 1.8 units of pseudo-rapidity of the center-of-mass
frame. Charged particles with momenta greater than 100 MeV/c are recorded.
Multiplicities in excess of 3,000 tracks per event are routinely reconstructed
in the software. The TPC measures 4 m in diameter by 4.2 m long, making it the
largest TPC in the world.Comment: 28 pages, 11 figure
Dielectron Cross Section Measurements in Nucleus-Nucleus Reactions at 1.0 A GeV
We present measured dielectron production cross sections for Ca+Ca, C+C,
He+Ca, and d+Ca reactions at 1.0 A GeV. Statistical uncertainties and
systematic effects are smaller than in previous DLS nucleus-nucleus data. For
pair mass < 0.35 GeV/c2 : 1) the Ca+Ca cross section is larger than the
previous DLS measurement and current model results, 2) the mass spectra suggest
large contributions from pi0 and eta Dalitz decays, and 3) dsigma/dM is
proportional to ApAt. For M > 0.5 GeV/c2 the Ca+Ca to C+C cross section ratio
is significantly larger than the ratio of ApAt values.Comment: Submitted to Physical Review Letters. Further analysis information
will be posted on our web pages -- http://macdls.lbl.gov Figure 1 has been
redrawn to make more legible. Text modified to support redrawn figur
Inclusive Dielectron Cross Sections in p+p and p+d Interactions at Beam Energies from 1.04 to 4.88 GeV
Measurements of dielectron production in p+p and p+d collisions with beam
kinetic energies from 1.04 to 4.88 GeV are presented. The differential cross
section is presented as a function of invariant pair mass, transverse momentum,
and rapidity. The shapes of the mass spectra and their evolution with beam
energy provide information about the relative importance of the various
dielectron production mechanisms in this energy regime. The p+d to p+p ratio of
the dielectron yield is also presented as a function of invariant pair mass,
transverse momentum, and rapidity. The shapes of the transverse momentum and
rapidity spectra from the p+d and p+p systems are found to be similar to one
another for each of the beam energies studied. The beam energy dependence of
the integrated cross sections is also presented.Comment: 15 pages and 16 figure
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