pinecone/core-2020-05-10-deduplication huggingface dataset:
Leptonic decays of the Ds meson

The purely leptonic decays Ds -> tau nu and Ds -> mu nu are studied in a
sample of four million hadronic Z decays collected with the ALEPH detector at
the LEP e+e- collider from 1991 to 1995. The branching fractions are extracted
from a combination of two analyses, one optimized to select Ds -> tau nu decays
with tau -> e nu nubar or mu nu nubar, and the other optimized for Ds-> mu nu
decays. The results are used to evaluate the Ds decay constant, within the
Standard Model: fDs = [285 +- 19(stat) +- 40 (syst)] MeVComment: 23 pages, 10 figure
Relating production and masses of the vector and P-wave mesons for light
  and heavy flavours al LEP

The production rates of primary vector and P-wave mesons in Z hadronic decays
are analysed. The mass dependence of production rates for the bottom, charm,
strange charm and three families of the light-flavour mesons is found to be
very similar, allowing to relate the relative production rates for mesons with
different flavours and, possibly, their masses. The strange axial mesons
K_1(1273) and K_1(1402) might be assigned to the 1^+(1/2) and 1^+(3/2) levels
degenerate with the 0^+(1/2) and 2^+(3/2) levels of the K^*_0(1430) and
K^*_2(1430), respectively, if the observed K^*_0(1430) mass is replaced by its
``bare'' q\bar{q} mass corresponding to the K-matrix pole and close to the
K_1(1273) mass. Then the 0^+(1/2) and 1^+(1/2) levels are below the 1^+(3/2)
and 2^+(3/2) levels for the strange, charm and bottom mesons.Comment: Accepted by Phys. Lett.
Decay of Affleck-Dine Condensates with Application to Q-balls

Analytical and numerical estimates show that a charged Affleck-Dine
condensate will fracture into Q-balls only when the Hubble time is
significantly larger than the inverse soft-breaking mass of the field in
question. This would generally imply that the decay of the field into light
fermions will compete with Q-ball formation. We will show that for typical flat
directions the large field value will significantly suppress decays of the
condensate to fermions even if no baryon charge asymmetry exists. We will
consider the details of the decay process for a condensate that does carry
charge, and show that it is qualitatively different from that of an uncharged
condensate. Finally, we will consider the possibility of resonant production of
heavy bosons. We will show that this can have a strong effect on the
condensate. Contrary to intuition, however, our results indicate that boson
production would actually assist Q-ball formation in condensates with
significant charge.Comment: 9 pages, 1 figure. Uses elsart.cl
Sparsely Sampling the Sky: Regular vs Random Sampling

The next generation of galaxy surveys, aiming to observe millions of
galaxies, are expensive both in time and cost. This raises questions regarding
the optimal investment of this time and money for future surveys. In a previous
work, it was shown that a sparse sampling strategy could be a powerful
substitute for the contiguous observations. However, in this previous paper a
regular sparse sampling was investigated, where the sparse observed patches
were regularly distributed on the sky. The regularity of the mask introduces a
periodic pattern in the window function, which induces periodic correlations at
specific scales. In this paper, we use the Bayesian experimental design to
investigate a random sparse sampling, where the observed patches are randomly
distributed over the total sparsely sampled area. We find that, as there is no
preferred scale in the window function, the induced correlation is evenly
distributed amongst all scales. This could be desirable if we are interested in
specific scales in the galaxy power spectrum, such as the Baryonic Acoustic
Oscillation (BAO) scales. However, for constraining the overall galaxy power
spectrum and the cosmological parameters, there is no preference over regular
or random sampling. Hence any approach that is practically more suitable can be
chosen and we can relax the regular-grid condition for the distribution of the
observed patches.Comment: arXiv admin note: text overlap with arXiv:1212.319
On the Ginzburg--Landau Functional in the Surface Superconductivity
  Regime

We present new estimates on the two-dimensional Ginzburg-Landau energy of a
type-II superconductor in an applied magnetic field varying between the second
and third critical fields. In this regime, superconductivity is restricted to a
thin layer along the boundary of the sample. We provide new energy lower
bounds, proving that the Ginzburg-Landau energy is determined to leading order
by the minimization of a simplified 1D functional in the direction
perpendicular to the boundary. Estimates relating the density of the
Ginzburg-Landau order parameter to that of the 1D problem follow. In the
particular case of a disc sample, a refinement of our method leads to a
pointwise estimate on the Ginzburg-Landau order parameter, thereby proving a
strong form of uniformity of the surface superconductivity layer, related to a
conjecture by Xing-Bin Pan.Comment: Revision of the version published in Communications in Mathematical
  Physics 332 (3), 1297-1343 (2014). Minor mistakes corrected and Theorem 2.4
  reformulated accordingl
Modulated phases and devil's staircases in a layered mean-field version
  of the ANNNI model

We investigate the phase diagram of a spin-$1/2$ Ising model on a cubic
lattice, with competing interactions between nearest and next-nearest neighbors
along an axial direction, and fully connected spins on the sites of each
perpendicular layer. The problem is formulated in terms of a set of
noninteracting Ising chains in a position-dependent field. At low temperatures,
as in the standard mean-feild version of the Axial-Next-Nearest-Neighbor Ising
(ANNNI) model, there are many distinct spatially commensurate phases that
spring from a multiphase point of infinitely degenerate ground states. As
temperature increases, we confirm the existence of a branching mechanism
associated with the onset of higher-order commensurate phases. We check that
the ferromagnetic phase undergoes a first-order transition to the modulated
phases. Depending on a parameter of competition, the wave number of the striped
patterns locks in rational values, giving rise to a devil's staircase. We
numerically calculate the Hausdorff dimension $D_{0}$ associated with these
fractal structures, and show that $D_{0}$ increases with temperature but seems
to reach a limiting value smaller than $D_{0}=1$.Comment: 17 pages, 6 figure
Planck intermediate results. XVIII The millimetre and sub-millimetre
  emission from planetary nebulae

Late stages of stellar evolution are characterized by copious mass-loss
events whose signature is the formation of circumstellar envelopes (CSE).
Planck multi-frequency measurements have provided relevant information on a
sample of Galactic planetary nebulae (PNe) in the important and relatively
unexplored observational band between 30 and 857GHz. Planck enables the
assembly of comprehensive PNe spectral energy distributions (SEDs) from radio
{\bf to} far-infrared frequencies. Modelling of the derived SEDs provides us
with information on physical properties of CSEs and the mass content of both
main components: ionised gas, traced by the free-free emission at cm--mm waves;
and thermal dust, traced by the millimetre and far-IR emission. In particular,
the amount of ionised gas and dust has been derived here. Such quantities have
also been estimated for the very young PN CRL618, where the strong variability
observed in its radio and millimetre emission has previously prevented the
construction of its SED. A morphological study of the Helix Nebula has also
been performed. Planck maps reveal, for the first time, the spatial
distribution of the dust inside the envelope, allowing us to identify different
components, the most interesting of which is a very extended component (up to
1pc) that may be related to a region where the slow expanding envelope is
interacting with the surrounding interstellar medium.Comment: 18 pages, 14 figures; accepted for publication in A&
Trace decategorification of categorified quantum sl(2)

The trace or the $0$th Hochschild--Mitchell homology of a linear category
$\mathcal{C}$ may be regarded as a kind of decategorification of $\mathcal{C}$.
We compute traces of the two versions $\dot{\mathcal{U}}$ and
$\dot{\mathcal{U}}^*$ of categorified quantum $\mathfrak{sl}_2$ introduced by
the third author. One version of the trace coincides with the split
Grothendieck group $K_0(\dot{\mathcal{U}})$, which is known to be isomorphic to
the the integral idempotented form $\dot{\mathbf{U}}(\mathfrak{sl}_2)$ of
quantum $\mathfrak{sl}(2)$. The higher Hochschild--Mitchell homology in this
case is zero. The trace of the second version is isomorphic to the idempotented
integral form of the current algebra $\mathbf{U}(\mathfrak{sl}_2[t])$.Comment: 33 pages, xypic figure
Thermal suppression of moving heavy quark pairs in strongly coupled
  plasma

The imaginary part of the heavy quark-antiquark potential experienced by
moving heavy quarkonia in strongly coupled plasmas dual to theories of gravity
is computed by considering thermal worldsheet fluctuations of the holographic
Nambu-Goto string. General results for a wide class of gravity duals are
presented and an explicit formula for $\mathrm{Im} \, V_{Q\bar{Q}}$ is found in
the case where the axis of the moving $\bar{Q}Q$ pair has an arbitrary
orientation with respect to its velocity in the plasma. These results are
applied to the study of heavy quarkonia propagating through a strongly coupled
$\mathcal{N} = 4$ SYM plasma. Our results indicate that the onset of
$\mathrm{Im} \, V_{Q\bar{Q}}$ decreases with increasing rapidity (though our
analysis is limited to slowly moving quarkonia) and that, in general, a
$Q\bar{Q}$ pair is more strongly bound if its axis is aligned with its
direction of motion through the strongly coupled plasma.Comment: 30 pages, 13 figures, references added. Revised discussio
Collins and Sivers asymmetries in muonproduction of pions and kaons off
  transversely polarised proton

Measurements of the Collins and Sivers asymmetries for charged pions and
charged and neutral kaons produced in semi-inclusive deep-inelastic scattering
of high energy muons off transversely polarised protons are presented. The
results were obtained using all the available COMPASS proton data, which were
taken in the years 2007 and 2010. The Collins asymmetries exhibit in the
valence region a non-zero signal for pions and there are hints of non-zero
signal also for kaons. The Sivers asymmetries are found to be positive for
positive pions and kaons and compatible with zero otherwise.Comment: 15 pages, 13 figures and 1 tabl
Viability of minimal left-right models with discrete symmetries

We provide a systematic study of minimal left-right models that are invariant
under $P$, $C$, and/or $CP$ transformations. Due to the high amount of symmetry
such models are quite predictive in the amount and pattern of $CP$ violation
they can produce or accommodate at lower energies. Using current experimental
constraints some of the models can already be excluded. For this purpose we
provide an overview of the experimental constraints on the different left-right
symmetric models, considering bounds from colliders, meson-mixing and
low-energy observables, such as beta decay and electric dipole moments. The
features of the various Yukawa and Higgs sectors are discussed in detail. In
particular, we give the Higgs potentials for each case, discuss the possible
vacua and investigate the amount of fine-tuning present in these potentials. It
turns out that all left-right models with $P$, $C$, and/or $CP$ symmetry have a
high degree of fine-tuning, unless supplemented with mechanisms to suppress
certain parameters. The models that are symmetric under both $P$ and $C$ are
not in accordance with present observations, whereas the models with either
$P$, $C$, or $CP$ symmetry can not be excluded by data yet. To further
constrain and discriminate between the models measurements of $B$-meson
observables at LHCb and $B$-factories will be especially important, while
measurements of the EDMs of light nuclei in particular could provide
complementary tests of the LRMs.Comment: Minor modifications, added references, matches published version in
  Nuclear Physics
Signatures of massive collisions in debris discs

Violent stochastic collisional events have been invoked as a possible
explanation for some debris discs displaying pronounced asymmetries or having a
great luminosity excess. So far, no thorough modelling of the consequences of
such events has been carried out, mainly because of the extreme numerical
challenge of coupling the dynamical and collisional evolution of dust.
  We perform the first fully self-consistent modelling of the aftermath of
massive breakups in debris discs. We follow the collisional and dynamical
evolution of dust released after the breakup of a Ceres-sized body at 6 AU from
its central star. We investigate the duration, magnitude and spatial structure
of the signature left by such a violent event, as well as its observational
detectability.
  We use the recently developed LIDT-DD code (Kral et al., 2013), which handles
the coupled collisional and dynamical evolution of debris discs. The main focus
is placed on the complex interplay between destructive collisions, Keplerian
dynamics and radiation pressure forces. We use the GRaTer package to estimate
the system's luminosity at different wavelengths.
  The breakup of a Ceres-sized body at 6 AU creates an asymmetric dust disc
that is homogenized, by the coupled action of collisions and dynamics, on a
timescale of a few $10^5$ years. The luminosity excess in the breakup's
aftermath should be detectable by mid-IR photometry, from a 30 pc distance,
over a period of $\sim 10^6$ years that exceeds the duration of the asymmetric
phase of the disc (a few $10^5$ years). As for the asymmetric structures, we
derive synthetic images for the SPHERE/VLT and MIRI/JWST instruments, showing
that they should be clearly visible and resolved from a 10 pc distance. Images
at 1.6$\mu$m (marginally), 11.4 and 15.5$\mu$m would show the inner disc
structures while 23$\mu$m images would display the outer disc asymmetries.Comment: 16 pages, 14 figures, abstract shortened, accepted for publication in
  A&
Drell-Yan and J/psi Production in High Energy Proton-Nucleus and
  Nucleus-Nucleus Collisions

The distributions of outgoing protons and charged hadrons in high energy
proton-nucleus collisions are described rather well by a linear extrapolation
from proton-proton collisions. This linear extrapolation is applied to
precisely measured Drell-Yan cross sections for 800 GeV protons incident on a
variety of nuclear targets. The deviation from linear scaling in the atomic
number A can be accounted for by energy degradation of the proton as it passes
through the nucleus if account is taken of the time delay of particle
production due to quantum coherence. We infer an average proper coherence time
of 0.4 +/- 0.1 fm/c. Then we apply the linear extrapolation to measured J/psi
production cross sections for 200 and 450 GeV/c protons incident on a variety
of nuclear targets. Our analysis takes into account energy loss of the beam
proton, the time delay of particle production due to quantum coherence, and
absorption of the J/psi on nucleons. The best representation is obtained for a
coherence time of 0.5 fm/c, which is consistent with Drell-Yan production, and
an absorption cross section of 3.6 mb, which is consistent with the value
deduced from photoproduction of the J/psi on nuclear targets. Finally, we
compare to recent J/psi data from S+U and Pb+Pb collisions at the SPS. The
former are reproduced reasonably well with no new parameters, but not the
latter.Comment: Talks given at Quark Matter '99, the 14th International Conference on
  Ultra-Relativistic Nucleus-Nucleus Collisions, Torino, Italy, May 10-14,
  1999. 10 pages, five figure
Screening Length in 2+1-dimensional Abelian Chern-Simons Theories

In this paper, we systematically study the question of screening length in
Abelian Chern-Simons theories. In the Abelian Higgs theory, where there are two
massive poles in the gauge propagator at the tree level, we show that the
coefficient of one of them becomes negligible at high temperature and that the
screening length is dominantly determined by the parity violating part of the
self-energy. In this theory, static magnetic fields are screened. In the
fermion theory, on the other hand, the parity conserving part of the
self-energy determines the screening length and static magnetic fields are not
screened. Several other interesting features are also discussed.Comment: Latex, 14 pages, 1 figur
Non-commutative integration calculus

We discuss a non--commutative integration calculus arising in the mathematical description of anomalies in fermion--Yang--Mills systems. We consider the differential complex of forms u_0\ccr{\eps}{u_1}\cdots\ccr{\eps}{u_n} with \eps a grading operator on a Hilbert space \cH and u_i bounded operators on \cH which naturally contains the compactly supported de Rham forms on \R^d (i.e.\ \eps is the sign of the free Dirac operator on \R^d and \cH a L^2--space on \R^d). We present an elementary proof that the integral of d--forms \int_{\R^d}\trac{X_0\dd X_1\cdots \dd X_d} for X_i\in\Map(\R^d;\gl_N), is equal, up to a constant, to the conditional Hilbert space trace of \Gamma X_0\ccr{\eps}{X_1}\cdots\ccr{\eps}{X_d} where \Gamma=1 for d odd and \Gamma=\gamma_{d+1} (`\gamma_5--matrix') a spin matrix anticommuting with \eps for d even. This result provides a natural generalization of integration of de Rham forms to the setting of Connes' non--commutative geometry which involves the ordinary Hilbert space trace rather than the Dixmier trace
Can Naked Singularities Yield $\gamma$ Ray Bursts?

Gamma-ray bursts are believed to be the most luminous objects in the Universe. There has been some suggestion that these arise from quantum processes around naked singularities. The main problem with this suggestion is that all known examples of naked singularities are massless and hence there is effectively no source of energy. It is argued that a globally naked singularity coupled with quantum processes operating within a distance of the order of Planck length of the singularity will probably yield energy burst of the order of M_pc^2\approx2\times 10^{16} ergs, where M_p is the Planck mass
Exact Chiral Symmetry for Domain Wall Fermions with Finite $L_{s}$

We show how the standard domain wall action can be simply modified to allow arbitrarily exact chiral symmetry at finite fifth dimensional extent $L_s$. We note that the method can be used for both quenched and dynamical calculations. We test the method using smooth and thermalized gauge field configurations. We also make comparisons of the performance (cost) of the domain wall operator for spectroscopy compared to other methods such as the overlap-Dirac operator and find both methods are comparable in cost
Critical RSOS and Minimal Models I: Paths, Fermionic Algebras and Virasoro Modules

We consider sl(2) minimal conformal field theories on a cylinder from a lattice perspective. To each allowed one-dimensional configuration path of the A_L Restricted Solid-on-Solid (RSOS) models we associate a physical state |h> and a monomial in a finite fermionic algebra. The orthonormal states produced by the action of these monomials on the primary states generate finite Virasoro modules with dimensions given by the finitized Virasoro characters $\chi^{(N)}_h(q)$. These finitized characters are the generating functions for the double row transfer matrix spectra of the critical RSOS models. We argue that a general energy-preserving bijection exists between the one-dimensional configuration paths and the eigenstates of these transfer matrices and exhibit this bijection for the critical and tricritical Ising models in the vacuum sector. Our results extend to Z_{L-1} parafermion models by duality
Restriction categories III: colimits, partial limits, and extensivity

A restriction category is an abstract formulation for a category of partial
maps, defined in terms of certain specified idempotents called the restriction
idempotents. All categories of partial maps are restriction categories;
conversely, a restriction category is a category of partial maps if and only if
the restriction idempotents split. Restriction categories facilitate reasoning
about partial maps as they have a purely algebraic formulation.
  In this paper we consider colimits and limits in restriction categories. As
the notion of restriction category is not self-dual, we should not expect
colimits and limits in restriction categories to behave in the same manner. The
notion of colimit in the restriction context is quite straightforward, but
limits are more delicate. The suitable notion of limit turns out to be a kind
of lax limit, satisfying certain extra properties.
  Of particular interest is the behaviour of the coproduct both by itself and
with respect to partial products. We explore various conditions under which the
coproducts are ``extensive'' in the sense that the total category (of the
related partial map category) becomes an extensive category. When partial
limits are present, they become ordinary limits in the total category. Thus,
when the coproducts are extensive we obtain as the total category a lextensive
category. This provides, in particular, a description of the extensive
completion of a distributive category.Comment: 39 page
Low-energy pi pi photoproduction off nuclei

In the present paper we investigate pi0 pi0 and pi(+/-)pi0 photoproduction
off complex nuclei at incident beam energies of 400-460 MeV. Simulations of two
pion photoproduction on protons and nuclei are performed by means of a
semi-classical BUU transport model including a full coupled-channel treatment
of the final state interactions. Elastic scattering of the final state pions
with the nucleons in the surrounding nuclear medium is found to yield a
downward shift of the pi pi invariant mass distribution. We show that the
target mass dependence of the pi0 pi0 invariant mass spectrum as measured by
the TAPS collaboration can be explained without introducing medium effects
beyond absorption and quasi-elastic scattering of the final state particles. On
the other hand, we find considerable discrepancies with the data in the
pi(+/-)pi0 channel, which are not understood.Comment: 6 pages, 4 figure
Nucleon-Meson Coupling Constants and Form Factors in the Quark Model

We demonstrate the calculation of the coupling constants and form factors
required by effective hadron lagrangians using the quark model. These relations
follow from equating expressions for strong transition amplitudes in the two
approaches. As examples we derive the NNm nucleon-meson coupling constants and
form factors for m = pi, eta, eta', sigma, a_0, omega and rho, using harmonic
oscillator quark model meson and baryon wavefunctions and the 3P0 decay model;
this is a first step towards deriving a quark-based model of the NN force at
all separations. This technique should be useful in the application of
effective lagrangians to processes in which the lack of data precludes the
direct determination of coupling constants and form factors from experiment.Comment: 7 pages, 4 figures, 1 tabl