907 research outputs found
The QCD equation of state at nonzero densities: lattice result
In this letter we give the equation of state of QCD at finite temperatures
and densities. The recently proposed overlap improving multi-parameter
reweighting technique is used to determine observables at nonvanishing chemical
potentials. Our results are obtained by studying n_f=2+1 dynamical staggered
quarks with semi-realistic masses on N_t=4 lattices.Comment: 5 pages, 6 figure
6D Dyonic String With Active Hyperscalars
We derive the necessary and sufficient conditions for the existence of a
Killing spinor in N=(1,0) gauge supergravity in six dimensions coupled to a
single tensor multiplet, vector multiplets and hypermultiplets. These are shown
to imply most of the field equations and the remaining ones are determined. In
this framework, we find a novel 1/8 supersymmetric dyonic string solution with
nonvanishing hypermultiplet scalars. The activated scalars parametrize a 4
dimensional submanifold of a quaternionic hyperbolic ball. We employ an
identity map between this submanifold and the internal space transverse to the
string worldsheet. The internal space forms a 4 dimensional analog of the
Gell-Mann-Zwiebach tear-drop which is noncompact with finite volume. While the
electric charge carried by the dyonic string is arbitrary, the magnetic charge
is fixed in Planckian units, and hence necessarily non-vanishing. The source
term needed to balance a delta function type singularity at the origin is
determined. The solution is also shown to have 1/4 supersymmetric AdS_3 x S^3
near horizon limit where the radii are proportional to the electric charge.Comment: 28 pages, latex, minor corrections mad
The QCD transition temperature: results with physical masses in the continuum limit
The transition temperature () of QCD is determined by Symanzik improved
gauge and stout-link improved staggered fermionic lattice simulations. We use
physical masses both for the light quarks () and for the strange quark
(). Four sets of lattice spacings (=4,6,8 and 10) were used to carry
out a continuum extrapolation. It turned out that only =6,8 and 10 can be
used for a controlled extrapolation, =4 is out of the scaling region.
Since the QCD transition is a non-singular cross-over there is no unique .
Thus, different observables lead to different numerical values even in
the continuum and thermodynamic limit. The peak of the renormalized chiral
susceptibility predicts =151(3)(3) MeV, wheres -s based on the
strange quark number susceptibility and Polyakov loops result in 24(4) MeV and
25(4) MeV larger values, respectively. Another consequence of the cross-over is
the non-vanishing width of the peaks even in the thermodynamic limit, which we
also determine. These numbers are attempted to be the full result for the
0 transition, though other lattice fermion formulations (e.g. Wilson)
are needed to cross-check them.Comment: 13 pages 5 figures. Final version, published in Phys.Lett.
FastJet user manual
FastJet is a C++ package that provides a broad range of jet finding and
analysis tools. It includes efficient native implementations of all widely used
2-to-1 sequential recombination jet algorithms for pp and e+e- collisions, as
well as access to 3rd party jet algorithms through a plugin mechanism,
including all currently used cone algorithms. FastJet also provides means to
facilitate the manipulation of jet substructure, including some common boosted
heavy-object taggers, as well as tools for estimation of pileup and
underlying-event noise levels, determination of jet areas and subtraction or
suppression of noise in jets.Comment: 69 pages. FastJet 3 is available from http://fastjet.fr
Open Cosmic Strings in Black Hole Space-Times
We construct open cosmic string solutions in Schwarzschild black hole and
non-dilatonic black p-brane backgrounds. These strings can be thought to
stretch between two D-branes or between a D-brane and the horizon in curved
space-time. We study small fluctuations around these solutions and discuss
their basic properties.Comment: 11 pages, REVTex, 5 figures, a reference adde
Electrified BPS Giants: BPS configurations on Giant Gravitons with Static Electric Field
We consider D3-brane action in the maximally supersymmetric type IIB
plane-wave background. Upon fixing the light-cone gauge, we obtain the
light-cone Hamiltonian which is manifestly supersymmetric. The 1/2 BPS
solutions of this theory (solutions which preserve 16 supercharges) are either
of the form of spherical three branes, the giant gravitons, or zero size point
like branes. We then construct specific classes of 1/4 BPS solutions of this
theory in which static electric field on the brane is turned on. These
solutions are deformations about either of the two 1/2 BPS solutions. In
particular, we study in some detail 1/4 BPS configurations with electric dipole
on the three sphere giant, i.e. BIons on the giant gravitons, which we hence
call BIGGons. We also study BPS configurations corresponding to turning on a
background uniform constant electric field. As a result of this background
electric field the three sphere giant is deformed to squashed sphere, while the
zero size point like branes turn into circular or straight fundamental strings
in the plane-wave background, with their tension equal to the background
electric field.Comment: 32 pages, 1 eps figure; v2: Presentation of derivation of light-cone
Hamiltonian improved, Refs adde
Lattice QCD at finite T and \mu
Recent results of lattice QCD at finite temperature and density are reviewed.
At vanishing density the transition temperature, the equation of state and
hadron properties are discussed both for the pure gauge theory and for
dynamical staggered, Wilson and overlap fermions. The second part deals with
finite density. There are recent results for full QCD at finite temperature and
moderate density, while at larger densities QCD-like models are studied.Comment: 14 pages, 19 figures, lattice2003(plenary). Minor correction
IGF2BP2 alternative variants associated with glutamic acid decarboxylase antibodies negative diabetes in Malaysian subjects
Background: The association of Insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) common variants (rs4402960 and rs1470579) with type 2 diabetes (T2D) has been performed in different populations. The aim of this study was to evaluate the association of alternative variants of IGF2BP2; rs6777038, rs16860234 and rs7651090 with glutamic acid decarboxylase antibodies (GADA) negative diabetes in Malaysian Subjects. Methods/Principal Findings: IGF2BP2; rs6777038, rs16860234 and rs7651090 single nucleotide polymorphisms (SNPs) were genotyped in 1107 GADA negative diabetic patients and 620 control subjects of Asian from Malaysia. The additive genetic model adjusted for age, race, gender and BMI showed that alternative variants; rs6777038, rs16860234 and rs7651090 of IGF2BP2 associated with GADA negative diabetes (OR = 1.21; 1.36; 1.35, P = 0.03; 0.0004; 0.0002, respectively). In addition, the CCG haplotype and diplotype CCG-TCG increased the risk of diabetes (OR = 1.51, P = 0.01; OR = 2.36, P = 0.009, respectively). Conclusions/Significance: IGF2BP2 alternative variants were associated with GADA negative diabetes. The IGF2BP2 haplotypes and diplotypes increased the risk of diabetes in Malaysian subject
Neutrino-Deuteron Scattering in Effective Field Theory at Next-to-Next-to Leading Order
We study the four channels associated with neutrino-deuteron breakup
reactions at next-to-next to leading order in effective field theory. We find
that the total cross-section is indeed converging for neutrino energies up to
20 MeV, and thus our calculations can provide constraints on theoretical
uncertainties for the Sudbury Neutrino Observatory. We stress the importance of
a direct experimental measurement to high precision in at least one channel, in
order to fix an axial two-body counterterm.Comment: 32 pages, 14 figures (eps
- …