749 research outputs found
Holographic Bosonic Technicolor
We consider a technicolor model in which the expectation value of an
additional, possibly composite, scalar field is responsible for the generation
of fermion masses. We define the dynamics of the strongly coupled sector by
constructing its holographic dual. Using the AdS/CFT correspondence, we study
the S parameter and the phenomenology of the light technihadrons. We find that
the S parameter is small over a significant region of the model's parameter
space. The particle spectrum is distinctive and includes a nonstandard Higgs
boson as well as heavier hadronic resonances. Technihadron masses and decay
rates are calculated holographically, as a function of the model's parameters.Comment: 20 Pages, 4 eps figures, REVTex. Minor corrections and comments adde
Self-bound dense objects in holographic QCD
We study a self-bound dense object in the hard wall model. We consider a
spherically symmetric dense object which is characterized by its radial density
distribution and non-uniform but spherically symmetric chiral condensate. For
this we analytically solve the partial differential equations in the hard wall
model and read off the radial coordinate dependence of the density and chiral
condensate according to the AdS/CFT correspondence. We then attempt to describe
nucleon density profiles of a few nuclei within our framework and observe that
the confinement scale changes from a free nucleon to a nucleus. We briefly
discuss how to include the effect of higher dimensional operator into our
study. We finally comment on possible extensions of our work.Comment: 17 pages, 5 figures, figures replaced, minor revision, to appear in
JHE
Virtual Compton Scattering off a Spinless Target in AdS/QCD
We study the doubly virtual Compton scattering off a spinless target
within the Anti-de Sitter(AdS)/QCD formalism. We find
that the general structure allowed by the Lorentz invariance and gauge
invariance of the Compton amplitude is not easily reproduced with the standard
recipes of the AdS/QCD correspondence. In the soft-photon regime, where the
semi-classical approximation is supposed to apply best, we show that the
measurements of the electric and magnetic polarizabilities of a target like the
charged pion in real Compton scattering, can already serve as stringent tests.Comment: 21 pages, version to be published in JHEP
Weighted poolingâpractical and cost-effective techniques for pooled high-throughput sequencing
Motivation: Despite the rapid decline in sequencing costs, sequencing large cohorts of individuals is still prohibitively expensive. Recently, several sophisticated pooling designs were suggested that can identify carriers of rare alleles in large cohorts with a significantly smaller number of pools, thus dramatically reducing the cost of such large-scale sequencing projects. These approaches use combinatorial pooling designs where each individual is either present or absent from a pool. One can then infer the number of carriers in a pool, and by combining information across pools, reconstruct the identity of the carriers
Holographic two dimensional QCD and Chern-Simons term
We present a holographic realization of large Nc massless QCD in two
dimensions using a D2/D8 brane construction. The flavor axial anomaly is dual
to a three dimensional Chern-Simons term which turns out to be of leading
order, and it affects the meson spectrum and holographic renormalization in
crucial ways. The massless flavor bosons that exist in the spectrum are found
to decouple from the heavier mesons, in agreement with the general lore of
non-Abelian bosonization. We also show that an external dynamical photon
acquires a mass through the three dimensional Chern-Simons term as expected
from the Schwinger mechanism. Massless two dimensional QCD at large Nc exhibits
anti-vector-meson dominance due to the axial anomaly.Comment: 22 page
Matrix Models, Monopoles and Modified Moduli
Motivated by the Dijkgraaf-Vafa correspondence, we consider the matrix model
duals of N=1 supersymmetric SU(Nc) gauge theories with Nf flavors. We
demonstrate via the matrix model solutions a relation between vacua of theories
with different numbers of colors and flavors. This relation is due to an N=2
nonrenormalization theorem which is inherited by these N=1 theories.
Specializing to the case Nf=Nc, the simplest theory containing baryons, we
demonstrate that the explicit matrix model predictions for the locations on the
Coulomb branch at which monopoles condense are consistent with the quantum
modified constraints on the moduli in the theory. The matrix model solutions
include the case that baryons obtain vacuum expectation values. In specific
cases we check explicitly that these results are also consistent with the
factorization of corresponding Seiberg-Witten curves. Certain results are
easily understood in terms of M5-brane constructions of these gauge theories.Comment: 27 pages, LaTeX, 2 figure
Symmetry energy of dense matter in holographic QCD
We study the nuclear symmetry energy of dense matter using holographic QCD.
To this end, we consider two flavor branes with equal quark masses in a
D4/D6/D6 model. We find that at all densities the symmetry energy monotonically
increases. At small densities, it exhibits a power law behavior with the
density, .Comment: 9 pages, 3 figure
Redefining genomic privacy: trust and empowerment
Fulfilling the promise of the genetic revolution requires the analysis of large datasets containing information from thousands to millions of participants. However, sharing human genomic data requires protecting subjects from potential harm. Current models rely on de-identification techniques in which privacy versus data utility becomes a zero-sum game. Instead, we propose the use of trust-enabling techniques to create a solution in which researchers and participants both win. To do so we introduce three principles that facilitate trust in genetic research and outline one possible framework built upon those principles. Our hope is that such trust-centric frameworks provide a sustainable solution that reconciles genetic privacy with data sharing and facilitates genetic research
Holographic Hadrons in a Confining Finite Density Medium
We study a sector of the hadron spectrum in the presence of finite baryon
density. We use a non-supersymmetric gravity dual to a confining guage theory
which exhibits a running dilaton. The interaction of mesons with the finite
density medium is encoded in the dual theory by a force balancing between
flavor D7-branes and a baryon vertex provided by a wrapped D5-brane. When the
current quark mass m_q is sufficiently large, the meson mass reduces,
exhibiting an interesting spectral flow as we increase the baryon density while
it has a more complicated behaviour for very small m_q.Comment: 34 pages, 20 figures, errors for some figures are fixe
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