pinecone/core-2020-05-10-deduplication huggingface dataset:
Heterotic E6 GUTs and Partition Functions

The E6 grand unified theory is an attractive candidate intermediate theory
between the standard model and string theory. However, only one E6 grand
unified model with three generations and at least one adjoint Higgs field has
been derived from string theory in the literature, and this model is
phenomenologically unsatisfactory. Recently, in arXiv:1012.1690, we have
constructed two new such E6 grand unified models in heterotic asymmetric
orbifolds. Although our new models themselves cannot resolve the unsatisfactory
point in the previous model, our discovery raises hopes that one can construct
many other such models in this framework and find better models. Here, by
giving partition functions explicitly, we explain the details of our
construction. Utilizing the lattice engineering technique and the diagonal
embedding method, we can construct models systematically. We hope that these
techniques and the details of our construction will lead to more
phenomenologically desirable models.Comment: 42 pages, 2 figures, v2: text rearranged, version to appear in JHE
Holographic Brownian Motion in Magnetic Environments

Using the gauge/gravity correspondence, we study the dynamics of a heavy
quark in two strongly-coupled systems at finite temperature: Super-Yang-Mills
in the presence of a magnetic field and non-commutative Super-Yang-Mills. In
the former, our results agree qualitatively with the expected behavior from
weakly-coupled theories. In the latter, we propose a Langevin equation that
accounts for the effects of non-commutativity and we find new interesting
features. The equation resembles the structure of Brownian motion in the
presence of a magnetic field and implies that the fluctuations along
non-commutative directions are correlated. Moreover, our results show that the
viscosity is smaller than the commutative case and that the diffusion
properties of the quark are unaffected by non-commutativity. Finally, we
compute the random force autocorrelator and verify that the
fluctuation-dissipation theorem holds in the presence of non-commutativity.Comment: 34 pages. v2: typos corrected. v3: title and abstract slightly
  modified in order to better reflect the contents of the paper; footnote 3 and
  one reference were also added; version accepted for publication in JHE
Reducing the 4d Index to the S^3 Partition Function

The superconformal index of a 4d gauge theory is computed by a matrix
integral arising from localization of the supersymmetric path integral on S^3 x
S^1 to the saddle point. As the radius of the circle goes to zero, it is
natural to expect that the 4d path integral becomes the partition function of
dimensionally reduced gauge theory on S^3. We show that this is indeed the case
and recover the matrix integral of Kapustin, Willet and Yaakov from the matrix
integral that computes the superconformal index. Remarkably, the superconformal
index of the "parent" 4d theory can be thought of as the q-deformation of the
3d partition function.Comment: 12 pages, Corrected typos in the appendix, Updated reference
Mass Hierarchy Determination Using Neutrinos from Multiple Reactors

We report the results of Monte Carlo simulations of a medium baseline reactor
neutrino experiment. The difference in baselines resulting from the 1 km
separations of Daya Bay and Ling Ao reactors reduces the amplitudes of 1-3
oscillations at low energies, decreasing the sensitivity to the neutrino mass
hierarchy. A perpendicular detector location eliminates this effect. We
simulate experiments under several mountains perpendicular to the Daya Bay/Ling
Ao reactors, considering in particular the background from the TaiShan and
YangJiang reactor complexes. In general the hierarchy can be determined most
reliably underneath the 1000 meter mountain BaiYunZhang, which is 44.5 km from
Daya Bay. If some planned reactors are not built then nearby 700 meter
mountains at 47-51 km baselines gain a small advantage. Neglecting their low
overhead burdens, hills near DongKeng would be the optimal locations. We use a
weighted Fourier transform to avoid a spurious dependence on the high energy
neutrino spectrum and find that a neural network can extract quantities which
determine the hierarchy marginally better than the traditional RL + PV.Comment: 22 pages, added details on the neural network (journal version
Pure spinors, twistors, and emergent supersymmetry

Starting with a classical action whose matter variables are a d=10 spacetime
vector $x^m$ and a pure spinor $\lambda^\alpha$, the pure spinor formalism for
the superstring is obtained by gauge-fixing the twistor-like constraint
$\partial x^m (\gamma_m \lambda)_\alpha =0$. The fermionic variables
$\theta^\alpha$ are Faddeev-Popov ghosts coming from this gauge-fixing and
replace the usual (b,c) ghosts coming from gauge-fixing the Virasoro
constraint. After twisting the ghost-number such that $\theta^\alpha$ has
ghost-number zero and $\lambda^\alpha$ has ghost-number one, the BRST
cohomology describes the usual spacetime supersymmetric states of the
superstring.Comment: 10 pages harvmac tex, added comments on small Hilbert space and U_0
  dependenc
The phase structure of black D1/D5 (F/NS5) system in canonical ensemble

In this paper, we explore means which can be used to change qualitatively the
phase structure of charged black systems. For this, we consider a system of
black D1/D5 (or its S-dual F/NS5). We find that the delocalized charged black
D-strings (F-strings) alone share the same phase structure as the charged black
D5 branes (NS5-branes), having no van der Waals-Maxwell liquid-gas type.
However, when the two are combined to form D1/D5 (F/NS5), the resulting phase
diagram has been changed dramatically to a richer one, containing now the above
liquid-gas type. The effect of adding the charged D-strings (F-strings) on the
phase structure can also be effectively described as a slight increase of the
transverse dimensions to the original D5 (NS5). This may be viewed as a
connection between a brane charge and a fraction of spatial dimension at least
in a thermodynamical sense.Comment: 31 pages, 3 Figures, 2 Tables, minor corrections, version published
  in JHE
Comments on a-maximization from gauged supergravity

In this paper we study the holographic dual to a-maximization in
five-dimensional N = 2 gauged supergravity. In particular, we apply the
procedure described by Tachikawa to specific examples consisting of holographic
duals to gauge theories arising as the IR limit of N M5-branes wrapping a
Riemann surface. A key element of this analysis is a consistent truncation of
seven-dimensional N = 4 SO(5) gauged supergravity reduced on a Riemann surface.
We demonstrate the consistency of this truncation and match to a sector of
five-dimensional matter-coupled N = 2 gauged supergravity. We determine the
U(1)_R symmetry and central charge of these theories and find agreement with
the literature. The final results provide a nontrivial illustration of the
holographic interpretation of a-maximization.Comment: v2: Generalized reduction to include cases of two-sphere and torus.
  Added references, fixed typo
Angular profile of Particle Emission from a Higher-dimensional Black
  Hole: Analytic Results

During the spin-down phase of the life of a higher-dimensional black hole,
the emission of particles on the brane exhibits a strong angular variation with
respect to the rotation axis of the black hole. It has been suggested that this
angular variation is the observable that could disentangle the dependence of
the radiation spectra on the number of extra dimensions and angular momentum of
the black hole. Working in the low-energy regime, we have employed analytical
formulae for the greybody factors, angular eigenvalues and eigenfunctions of
fermions and gauge bosons, and studied the characteristics of the corresponding
angular profiles of emission spectra in terms of only a few dominant partial
modes. We have confirmed that, in the low-energy channel, the emitted gauge
bosons become aligned to the rotation axis of the produced black hole while
fermions form an angle with the rotation axis whose exact value depends on the
angular-momentum of the black hole. In the case of scalar fields, we
demonstrated the existence of a "spherically-symmetric zone" that is followed
by the concentration of the emission on the equatorial plane, again in total
agreement with the exact numerical results.Comment: 27 pages, Latex2e file, 4 figure
Liouville's Imaginary Shadow

N=1 super Liouville field theory is one of the simplest non-rational
conformal field theories. It possesses various important extensions and
interesting applications, e.g. to the AGT relation with 4D gauge theory or the
construction of the OSP(1|2) WZW model. In both setups, the N=1 Liouville field
is accompanied by an additional free fermion. Recently, Belavin et al.
suggested a bosonization of the product theory in terms of two bosonic
Liouville fields. While one of these Liouville fields is standard, the second
turns out to be imaginary (or time-like). We extend the proposal to the R
sector and perform extensive checks based on detailed comparison of 3-point
functions involving several super-conformal primaries and descendants. On the
basis of such strong evidence we sketch a number of interesting potential
applications of this intriguing bosonization.Comment: 31 page
On Neutrino Flavor States

We review the issues associated with the construction of neutrino flavor
states. We then provide a consistent proof that the flavor states are
approximately well-defined only if neutrinos are ultra-relativistic or the mass
differences are negligible compared to energy. However, we show that weak
interactions can be consistently described by only neutrino mass eigenstates.
Meanwhile, the second quantization of neutrino flavor fields generally has no
physical relevance as their masses are indefinite. Therefore, the flavor states
are not physical quantum states and they should simply be interpreted as
definitions to denote specific linear combinations of mass eigenstates involved
in weak interactions. We also briefly discuss the implication of this work for
the mixing between active and heavy sterile neutrinos.Comment: 13 pages, v2: version to appear in JHE
Beyond LLM in M-theory

The Lin, Lunin, Maldacena (LLM) ansatz in D = 11 supports two independent
Killing directions when a general Killing spinor ansatz is considered. Here we
show that these directions always commute, identify when the Killing spinors
are charged, and show that both their inner product and resulting geometry are
governed by two fundamental constants. In particular, setting one constant to
zero leads to AdS7 x S4, setting the other to zero gives AdS4 x S7, while flat
spacetime is recovered when both these constants are zero. Furthermore, when
the constants are equal, the spacetime is either LLM, or it corresponds to the
Kowalski-Glikman solution where the constants are simply the mass parameter.Comment: 1+30 pages, footnote adde
A Zip-code for Quarks, Leptons and Higgs Bosons

The location of matter fields and the pattern of gauge symmetry in extra
dimensions are crucial ingredients for string model building. We analyze
realistic MSSM models from the heterotic Z6 Mini-Landscape and extract those
properties that are vital for their success. We find that Higgs bosons and the
top quark are not localized in extra dimensions and live in the full D=10
dimensional space-time. The first two families of quarks and leptons, however,
live at specific fixed points in extra dimensional space and exhibit a
(discrete) family symmetry. Within a newly constructed Z2XZ4 orbifold framework
we further elaborate on these location properties and the appearance of
discrete symmetries. A similar geometrical picture emerges. This particular
Zip-code for quarks, leptons and Higgs bosons seems to be of more general
validity and thus a useful guideline for realistic model building in string
theory.Comment: 42 pages, 8 figures. v2: published version, references adde
Probing Sterile Neutrino Parameters with Double Chooz, Daya Bay and RENO

In this work, we present a realistic analysis of the potential of the
present-day reactor experiments Double Chooz, Daya Bay and RENO for probing the
existence of sterile neutrinos. We present exclusion regions for sterile
oscillation parameters for each of these experiments, using simulations with
realistic estimates of systematic errors and detector resolutions, and compare
the sterile parameter sensitivity regions we obtain with the existing bounds
from other reactor experiments. We find that these experimental set-ups give
significant bounds on the parameter \Theta_{ee} especially in the low sterile
oscillation region 0.01 < \Delta m_{41}^2 < 0.05 eV^2. These bounds can add to
our understanding of the sterile neutrino sector since there is still a tension
in the allowed regions from different experiments for sterile parameters.Comment: 12 pages, 5 figure
Large N (=3) Neutrinos and Random Matrix Theory

The large N limit has been successfully applied to QCD, leading to
qualitatively correct results even for N=3. In this work, we propose to treat
the number N=3 of Standard Model generations as a large number. Specifically,
we apply this idea to the neutrino anarchy scenario and study neutrino physics
using Random Matrix Theory, finding new results in both areas. For neutrino
physics, we obtain predictions for the masses and mixing angles as a function
of the generation number N. The Seesaw mechanism produces a hierarchy of order
1/N^3 between the lightest and heaviest neutrino, and a theta(13) mixing angle
of order 1/N, in parametric agreement with experimental data when N goes to 3.
For Random Matrix Theory, this motivates the introduction of a new type of
ensemble of random matrices, the "Seesaw ensemble." Basic properties of such
matrices are studied, including the eigenvalue density and the interpretation
as a Coulomb gas system. Besides its mathematical interest, the Seesaw ensemble
may be useful in random systems where two hierarchical scales exist.Comment: 20 pages, 6 figures, 1 table; accepted version for JHEP, references
  adde
Time evolution of entanglement entropy from a pulse

We calculate the time evolution of the entanglement entropy in a 1+1 CFT with
a holographic dual when there is a localized left-moving packet of energy
density. We find the gravity result agrees with a field theory result derived
from the transformation properties of R\'enyi entropy. We are able to reproduce
behavior which qualitatively agrees with CFT results of entanglement entropy of
a system subjected to a local quench. In doing so we construct a finite
diffeomorphism which tales three-dimensional anti-de Sitter space in the
Poincar\'e patch to a general solution, generalizing the diffeomorphism that
takes the Poincar\'e patch a BTZ black hole. We briefly discuss the calculation
of correlation functions in these backgrounds and give results at large
operator dimension.Comment: 18 pages, 6 figure
Cleaning up the cosmological constant

We present a novel idea for screening the vacuum energy contribution to the
overall value of the cosmological constant, thereby enabling us to choose the
bare value of the vacuum curvature empirically, without any need to worry about
the zero-point energy contributions of each particle. The trick is to couple
matter to a metric that is really a composite of other fields, with the
property that the square-root of its determinant is the integrand of a
topological invariant, and/or a total derivative. This ensures that the vacuum
energy contribution to the Lagrangian is non-dynamical. We then give an
explicit example of a theory with this property that is free from Ostrogradski
ghosts, and is consistent with solar system physics and cosmological tests.Comment: 8 pages, typos corrected and more text added, version accepted for
  publication in JHE
Ultra-high energy collisions of nonequatorial geodesic particles near
  dirty black holes

We consider collision of two geodesic particles moving around rotating
stationary axially symmetric black holes. It is shown for arbitrary
nonequatorial motion that under certain conditions the energy in their centre
of mass frame can grow unbound (the so-called BSW effect). This generalizes the
previous results for equatorial motion around dirty (surrounded by matter)
black holes and nonequatorial motion around the Kerr metric. It turns out that
the BSW effect occurs near any point of the horizon surface. We do not use
special symmetries of space-time typical of the Kerr metric, so the results are
quite generic. The general scheme classifying all possible scenarios is
discussed.Comment: 10 pages. Minor corrections. To appear in JHE
Resummation in nonlinear equation for high energy factorizable gluon
  density and its extension to include coherence

Motivated by forthcoming p-Pb experiments at Large Hadron Collider which
require both knowledge of gluon densities accounting for saturation and for
processes at a wide range of $p_t$ we study basic momentum space evolution
equations of high energy QCD factorization. Solutions of those equations might
be used to form a set of gluon densities to calculate observables in
generalized high energy factorization. Moreover in order to provide a framework
for predictions for exclusive final states in p-Pb scattering with high $p_t$
we rewrite the equation for the high energy factorizable gluon density in a
resummed form, similarly to what has been done in \cite{Kutak:2011fu} for the
BK equation. The resummed equation is then extended to account for colour
coherence. This introduces an external scale to the evolution of the gluon
density, and therefore makes it applicable in studies of final states.Comment: 14 pages, appendix added, accepted for publication in JHE
Remarks on effective action and entanglement entropy of Maxwell field in
  generic gauge

We analyze the dependence of the effective action and the entanglement
entropy in the Maxwell theory on the gauge fixing parameter $a$ in $d$
dimensions. For a generic value of $a$ the corresponding vector operator is
nonminimal. The operator can be diagonalized in terms of the transverse and
longitudinal modes. Using this factorization we obtain an expression for the
heat kernel coefficients of the nonminimal operator in terms of the
coefficients of two minimal Beltrami-Laplace operators acting on 0- and
1-forms. This expression agrees with an earlier result by Gilkey et al. Working
in a regularization scheme with the dimensionful UV regulators we introduce
three different regulators: for transverse, longitudinal and ghost modes,
respectively. We then show that the effective action and the entanglement
entropy do not depend on the gauge fixing parameter $a$ provided the certain
($a$-dependent) relations are imposed on the regulators. Comparing the
entanglement entropy with the black hole entropy expressed in terms of the
induced Newton's constant we conclude that their difference, the so-called
Kabat's contact term, does not depend on the gauge fixing parameter $a$. We
consider this as an indication of gauge invariance of the contact term.Comment: 15 pages; v2: typos in eqs. (31), (32), (34), (36) corrected;
  discussion in section 6 expande
Axion-mediated dark matter and Higgs diphoton signal

We consider axion-mediated dark matter models motivated by Fermi gamma ray
line at 130 GeV, where anomaly interactions of an axion-like scalar mediate a
singlet Dirac fermion dark matter (DM) to electroweak gauge bosons. In these
models, extra vector-like leptons generate anomaly interactions for the axion
and can also couple to the SM Higgs boson to modify the Higgs-to-diphoton rate.
We can distinguish models by the branching fraction of the DM annihilation into
a photon pair, favoring the model with a triplet fermion. From the condition
that the lighter charged extra lepton must be heavier than dark matter for no
tree-level DM annihilations, we also show that the ratio of Higgs-to-diphoton
rate to the SM value is constrained by vacuum stability to 1.4(1.5) for the
cutoff scale of 10(1) TeV.Comment: 29 pages, 6 figures, references adde
Holographic Dual of the Lowest Landau Level

We describe the lowest Landau level of a quantum electron star in AdS4. In
the presence of a suitably strong magnetic field, the dynamics of fermions in
the bulk is effectively reduced from four to two dimensions. These
two-dimensional fermions can subsequently be treated using the techniques of
bosonization and the difficult many-body problem of building a gravitating,
charged quantum star is reduced to solving the sine-Gordon model coupled to a
gauge field and a metric. The kinks of the sine-Gordon model provide the
holographic dual of the lowest Landau levels of the strongly-coupled d=2+1
dimensional boundary field theory. The system exhibits order one oscillations
in the magnetic susceptibility, now arising as a classical effect in the bulk.
Moreover, as the chemical potential is varied, we find jumps in the charge
density, oscillations in the fractionalised charge density and plateaux in the
cohesive charge densityComment: 39 pages; 8 Figure
The hunt for New Physics in the Flavour Sector with up vector-like quarks

We analyse the possible presence of New Physics (NP) in the Flavour Sector and evaluate its potential for solving the tension between the experimental values of A(J/Psi KS) and Br(B+ -> tau(+)v(tau)) with respect to the Standard Model (SM) expectations. Updated model independent analyses, where NP contributions are allowed in B-d(0) - (B) over bar (0)(d) and B-s(0) - (B) over bar (0)(s) transitions, suggest the need of New Physics in the bd sector. A detailed analysis of recent Flavour data is then presented in the framework of a simple extension of the SM, where a Q = 2/3 vector-like isosinglet quark is added to the spectrum of the SM. Special emphasis is given to the implications of this model for correlations among various measurable quantities. We include constraints from all the relevant quark flavour sectors and give precise predictions for selected rare processes. We find important deviations from the SM in observables in the bd sector like the semileptonic asymmetry A(SL)(d), B-d(0) -> mu(+)mu(-) and A(SL)(s) - A(SL)(d). Other potential places where NP can show up include A(J/Psi Phi), gamma, K-L(0) -> pi(0)v (v) over bar, t -> Zq and D-0 -> mu(+)mu(-) among others. The experimental data favours in this model the existence of an up vector-like quark with a mass below 600(1000) GeV at 1(2) sigma
On the energy momentum dispersion in the lattice regularization

For a free scalar boson field and for U(1) gauge theory finite volume
(infrared) and other corrections to the energy-momentum dispersion in the
lattice regularization are investigated calculating energy eigenstates from the
fall off behavior of two-point correlation functions. For small lattices the
squared dispersion energy defined by $E_{\rm
dis}^2=E_{\vec{k}}^2-E_0^2-4\sum_{i=1}^{d-1}\sin(k_i/2)^2$ is in both cases
negative ($d$ is the Euclidean space-time dimension and $E_{\vec{k}}$ the
energy of momentum $\vec{k}$ eigenstates). Observation of $E_{\rm dis}^2=0$ has
been an accepted method to demonstrate the existence of a massless photon
($E_0=0$) in 4D lattice gauge theory, which we supplement here by a study of
its finite size corrections. A surprise from the lattice regularization of the
free field is that infrared corrections do {\it not} eliminate a difference
between the groundstate energy $E_0$ and the mass parameter $M$ of the free
scalar lattice action. Instead, the relation $E_0=\cosh^{-1} (1+M^2/2)$ is
derived independently of the spatial lattice size.Comment: 9 pages, 2 figures. Parts of the paper have been rewritten and
  expanded to clarify the result