631 research outputs found
The Thermodynamic Potentials of Kerr-AdS Black Holes and their CFT Duals
String or M-theory in the background of Kerr-AdS black holes is thought to be
dual to the large n limit of certain conformal field theories on a rotating
sphere at finite temperature. The five dimensional black hole is associated to
N=4 supersymmetric Yang-Mills theory on a rotating three-sphere and the four
dimensional one to the superconformal field theory of coinciding M2 branes on a
rotating two-sphere. The thermodynamic potentials can be expanded in inverse
powers of the radius of the sphere. We compute the leading and subleading terms
of this expansion in the field theory at one loop and compare them to the
corresponding supergravity expressions. The ratios between these terms at weak
and strong coupling turns out not to depend on the rotation parameters in the
case of N=4 SYM. For the field theory living on one M2 brane we find a
subleading logarithmic term. No such term arises from the supergravity
calculation.Comment: 14 pages (harvmac b-mode), signs corrected, minor changes otherwis
"Strongly interacting matter in magnetic fields": an overview
This is an introduction to the volume of Lecture Notes in Physics on
"Strongly interacting matter in magnetic fields". The volume combines
contributions written by a number of experts on different aspects of the
problem. The response of QCD matter to intense magnetic fields has attracted a
lot of interest recently. On the theoretical side, this interest stems from the
possibility to explore the plethora of novel phenomena arising from the
interplay of magnetic field with QCD dynamics. On the experimental side, the
interest is motivated by the recent results on the behavior of quark-gluon
plasma in a strong magnetic field created in relativistic heavy ion collisions
at RHIC and LHC. The purpose of this introduction is to provide a brief
overview and a guide to the individual contributions where these topics are
covered in detail.Comment: 12 pages, introduction to "Strongly interacting matter in magnetic
fields", Lect. Notes Phys. 871, 1 (2013), edited by D. Kharzeev, K.
Landsteiner, A. Schmitt, H.-U. Yee; v2: references update
(Anti)symmetric matter and superpotentials from IIB orientifolds
We study the IIB engineering of N=1 gauge theories with unitary gauge group
and matter in the adjoint and (anti)symmetric representations. We show that
such theories can be obtained as Z2 orientifolds of Calabi-Yau A2 fibrations,
and discuss the explicit T-duality transformation to an orientifolded
Hanany-Witten construction. The low energy dynamics is described by a geometric
transition of the orientifolded background. Unlike previously studied cases, we
show that the orientifold 5-`plane' survives the transition, thus bringing a
nontrivial contribution to the effective superpotential. We extract this
contribution by using matrix model results and compare with geometric data. A
Higgs branch of our models recovers the engineering of SO/Sp theories with
adjoint matter through an O5-`plane' T-dual to an O6-plane. We show that the
superpotential agrees with that produced by engineering through an O5-`plane'
dual to an O4-plane, even though the orientifold of this second construction is
replaced by fluxes after the transition.Comment: 40 page
More on Meta-Stable Brane Configuration
We describe the intersecting brane configuration of type IIA string theory
corresponding to the meta-stable nonsupersymmetric vacua in four dimensional
N=1 supersymmetric SU(N_c) gauge theory with an antisymmetric flavor, a
conjugate symmetric flavor, eight fundamental flavors, m_f fundamental flavors
and m_f antifundamental flavors. This is done by analyzing the N=1
supersymmetric SU(2m_f-N_c+4) magnetic gauge theory with dual matters and the
corresponding dual superpotential.Comment: 20 pp, 3 figures; Pages 11,12, and 14 improved; to appear in CQ
A model realisation of the Jaffe-Wilczek correlation for pentaquarks
We discuss a realisation of the pentaquark structure proposed by Jaffe and
Wilczek within a simple quark model with colour-spin contact interactions and
coloured harmonic confinement, which accurately describes the
splitting. In this model spatially compact diquarks are formed in the
pentaquark but no such compact object exists in the nucleon. The colour-spin
attraction brings the Jaffe-Wilczek-like state down to a low mass, compatible
with the experimental observation and below that of the naive ground state with
all -waves. We find, however, that although these trends are maintained, the
extreme effects observed do not survive the required ``smearing'' of the delta
function contact interaction. We also demonstrate the weakness of the
``schematic'' approximation when applied to a system containing a -wave. An
estimate of the anti-charmed pentaquark mass is made which is in line with the
Jaffe-Wilczek prediction and significantly less than the value reported by the
H1 collaboration.Comment: 10 pages, uses psfra
Meta-Stable Brane Configuration with Orientifold 6 Plane
We present the intersecting brane configuration of type IIA string theory
corresponding to the meta-stable nonsupersymmetric vacua in four dimensional
N=1 supersymmetric SU(N_c) gauge theory with a symmetric flavor, a conjugate
symmetric flavor and fundamental flavors. By studying the previously known
supersymmetric M5-brane curve, the M-theory lift for this type IIA brane
configuration, which consists of NS5-branes, D4-branes, D6-branes and an
orientifold 6-plane, is analyzed.Comment: 21 pp, 3 colored figures; stability arguments added in page 11 and
12, a typo in figure 3 corrected, and to appear in JHE
Prepotential and Instanton Corrections in N=2 Supersymmetric SU(N_1)xSU(N_2) Yang Mills Theories
In this paper we analyse the non-hyperelliptic Seiberg-Witten curves derived
from M-theory that encode the low energy solution of N=2 supersymmetric
theories with product gauge groups. We consider the case of a SU(N_1)xSU(N_2)
gauge theory with a hypermultiplet in the bifundamental representation together
with matter in the fundamental representations of SU(N_1) and SU(N_2). By means
of the Riemann bilinear relations that hold on the Riemann surface defined by
the Seiberg--Witten curve, we compute the logarithmic derivative of the
prepotential with respect to the quantum scales of both gauge groups. As an
application we develop a method to compute recursively the instanton
corrections to the prepotential in a straightforward way. We present explicit
formulas for up to third order on both quantum scales. Furthermore, we extend
those results to SU(N) gauge theories with a matter hypermultiplet in the
symmetric and antisymmetric representation. We also present some non-trivial
checks of our results.Comment: 21 pages, 2 figures, minor changes and references adde
Dense Quark Matter Conductivity in Ultra-Intense Magnetic Field
Heavy-ion collisions generate a huge magnetic field of the order of for the duration of about 0.2 fm/c. This time may become an order of
magnitude longer if the electrical conductivity of quark matter is large. We
calculate the conductivity in the regime of high density and show that contrary
to naive expectations it only weakly depends on the MF.Comment: 3 pages, 0 figure
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