1,292 research outputs found
The QCD equation of state at finite density from analytical continuation
We determine the equation of state of QCD at finite chemical potential, to
order , for a system of 2+1 quark flavors. The simulations are
performed at the physical mass for the light and strange quarks on several
lattice spacings; the results are continuum extrapolated using lattices of up
to temporal resolution. The QCD pressure and interaction measure are
calculated along the isentropic trajectories in the plane
corresponding to the RHIC Beam Energy Scan collision energies. Their behavior
is determined through analytic continuation from imaginary chemical potentials
of the baryonic density. We also determine the Taylor expansion coefficients
around from the simulations at imaginary chemical potentials.
Strangeness neutrality and charge conservation are imposed, to match the
experimental conditions.Comment: 5 pages, 4 figure
Discovery potential for Higgs bosons beyond the SM
The discovery potential of the CMS detector for the MSSM neutral and charged
Higgs bosons at the LHC is presented based on studies with full detector
simulation and event reconstruction of the principal discovery channels.Comment: Prepared for International Europhysics Conference on High Energy
Physics (EPS-HEP2007), Manchester, England, 19-25 Jul 200
Insight into the Charge Density Wave Gap from Contrast Inversion in Topographic STM Images
Charge density waves (CDWs) are understood in great detail in one dimension, but they remain largely enigmatic in two-dimensional systems. In particular, numerous aspects of the associated energy gap and the formation mechanism are not fully understood. Two long-standing riddles are the amplitude and position of the CDW gap with respect to the Fermi level (
E
F
) and the frequent absence of CDW contrast inversion (CI) between opposite bias scanning tunneling microscopy (STM) images. Here, we find compelling evidence that these two issues are intimately related. Combining density functional theory and STM to analyze the CDW pattern and modulation amplitude in
1
T
−
TiSe
2
, we find that CI takes place at an unexpected negative sample bias because the CDW gap opens away from
E
F
, deep inside the valence band. This bias becomes increasingly negative as the CDW gap shifts to higher binding energy with electron doping. This study shows the importance of CI in STM images to identify periodic modulations with a CDW and to gain valuable insight into the CDW gap, whose measurement is notoriously controversial
Rapid, simple and cost-effective molecular method to differentiate the temperature sensitive (ts+) MS-H vaccine strain and wild-type Mycoplasma synoviae isolates
Mycoplasma synoviae
infection in chickens and turkeys can cause respiratory disease,
infectious synovitis and eggshell apex abnormality; thus it is an economically important
pathogen. Control of
M
.
synoviae
infection comprises eradication, medication or vaccina-
tion. The differentiation of the temperature sensitive (ts
+
) MS-H vaccine strain from field iso-
lates is crucial during vaccination programs. Melt-curve and agarose gel based mismatch
amplification mutation assays (MAMA) are provided in the present study to distinguish
between the ts
+
MS-H vaccine strain, its non-temperature sensitive re-isolates and wild-
type
M
.
synoviae
isolates based on the single nucleotide polymorphisms at nt367 and nt629
of the
obg
gene. The two melt-MAMAs and the two agarose-MAMAs clearly distinguish the
ts
+
MS-H vaccine strain genotype from its non-temperature sensitive re-isolate genotype
and wild-type
M
.
synoviae
isolate genotype, and no cross-reactions with other
Mycoplasma
species infecting birds occur. The sensitivity of the melt-MAMAs and agarose-MAMAs was
10
3
and 10
4
copy numbers, respectively. The assays can be performed directly on clinical
samples and they can be run simultaneously at the same annealing temperature. The
assays can be performed in laboratories with limited facilities, using basic real-time PCR
machine or conventional thermocycler coupled with agarose gel electrophoresis. The
advantages of the described assays compared with previously used methods are simplicity,
sufficient sensitivity, time and cost effectiveness and specificity
A distinct peak-flux distribution of the third class of gamma-ray bursts: A possible signature of X-ray flashes?
Gamma-ray bursts are the most luminous events in the Universe. Going beyond
the short-long classification scheme we work in the context of three burst
populations with the third group of intermediate duration and softest spectrum.
We are looking for physical properties which discriminate the intermediate
duration bursts from the other two classes. We use maximum likelihood fits to
establish group memberships in the duration-hardness plane. To confirm these
results we also use k-means and hierarchical clustering. We use Monte-Carlo
simulations to test the significance of the existence of the intermediate group
and we find it with 99.8% probability. The intermediate duration population has
a significantly lower peak-flux (with 99.94% significance). Also, long bursts
with measured redshift have higher peak-fluxes (with 98.6% significance) than
long bursts without measured redshifts. As the third group is the softest, we
argue that we have {related} them with X-ray flashes among the gamma-ray
bursts. We give a new, probabilistic definition for this class of events.Comment: accepted for publication in Ap
Search for resonant diboson production in the ℓℓq q¯ final state in pp collisions at √ s = 8 TeV with the ATLAS detector
This paper reports on a search for narrow resonances in diboson production in the ℓℓq q¯ final state using pp collision data corresponding to an integrated luminosity o f 20 fb − 1 collected at √ s = 8 TeV with the ATLAS detector at the Large Hadron Collider. No significant excess of data events over the Standard Model expectation is observed. Upper limits at the 95% confidence level are set on the production cross section times branching ratio for Kaluza–Klein gravitons predicted by the Randall– Sundrum model and for Extended Gauge Model W ′ bosons. These results lead to the exclusion of mass values below 740 GeV and 1590 GeV for the graviton and W ′ boson respectivel
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