330 research outputs found
Prospects for natural SUSY
As we anticipate the first results of the 2016 run, we assess the discovery
potential of the LHC to `natural supersymmetry'. To begin with, we explore the
region of the model parameter space that can be excluded with various
centre-of-mass energies (13 TeV and 14 TeV) and different luminosities (20
fb, 100 fb, 300 fb and 3000 fb). We find that the
bounds at 95% CL on stops vary from GeV expected
this summer to GeV at the end of the high
luminosity run, while gluino bounds are expected to range from
GeV to GeV over the
same time period. However, more pessimistically we find that if no signal
begins to appear this summer, only a very small region of parameter space can
be discovered with 5- significance. For this conclusion to change, we
find that both theoretical and systematic uncertainties will need to be
significantly reduced.Comment: 19 pages, 13 figures, minor changes, Phys.Rev.D versio
Tidal Disruption Event Host Galaxies in the Context of the Local Galaxy Population
We study the properties of tidal disruption event (TDE) host galaxies in the
context of a catalog of ~500,000 galaxies from the Sloan Digital Sky Survey. We
explore whether selection effects can account for the overrepresentation of
TDEs in E+A/post-starburst galaxies by creating matched galaxy samples.
Accounting for possible selection effects due to black hole (BH) mass, redshift
completeness, strong AGN presence, bulge colors, and surface brightness can
reduce the apparent overrepresentation of TDEs in E+A host galaxies by a factor
of ~4 (from ~100-190 to ~25-48), but cannot fully explain the
preference. We find that TDE host galaxies have atypical photometric properties
compared to similar, "typical" galaxies. In particular, TDE host galaxies tend
to live in or near the "green valley" between star-forming and passive
galaxies, and have bluer bulge colors ( mag), lower
half-light surface brightnesses (by ~1 mag/arcsec), higher Sersic indices
(), and higher bulge-to-total-light ratios () than galaxies with matched BH masses. We find that TDE host
galaxies appear more centrally concentrated and that all have high galaxy
Sersic indices and fractions---on average in the top 10% of galaxies of
the same BH mass---suggesting a higher nuclear stellar density. We identify a
region in Sersic index and BH mass parameter space that contains ~2% of our
reference catalog galaxies but of TDE host galaxies. The unique
photometric properties of TDE host galaxies may be useful for selecting
candidate TDEs for spectroscopic follow-up observations in large transient
surveys.Comment: 26 pages, 11 figures, 5 tables. Published in Ap
DeepXS: Fast approximation of MSSM electroweak cross sections at NLO
We present a deep learning solution to the prediction of particle production
cross sections over a complicated, high-dimensional parameter space. We
demonstrate the applicability by providing state-of-the-art predictions for the
production of charginos and neutralinos at the Large Hadron Collider (LHC) at
the next-to-leading order in the phenomenological MSSM-19 and explicitly
demonstrate the performance for
and as
a proof of concept which will be extended to all SUSY electroweak pairs. We
obtain errors that are lower than the uncertainty from scale and parton
distribution functions with mean absolute percentage errors of well below
allowing a safe inference at the next-to-leading order with inference
times that improve the Monte Carlo integration procedures that have been
available so far by a factor of from
to per evaluation.Comment: 7 pages, 3 figure
Tidal Disruptions of Main Sequence Stars of Varying Mass and Age: Inferences from the Composition of the Fallback Material
We use a simple framework to calculate the time evolution of the composition
of the fallback material onto a supermassive black hole arising from the tidal
disruption of main sequence stars. We study stars with masses between 0.8 and
3.0 , at evolutionary stages from zero-age main sequence to
terminal-age main sequence, built using the Modules for Experiments in Stellar
Astrophysics code. We show that most stars develop enhancements in nitrogen
(N) and depletions in carbon (C) and oxygen (O) over their
lifetimes, and that these features are more pronounced for higher mass stars.
We find that, in an accretion-powered tidal disruption flare, these features
become prominent only after the time of peak of the fallback rate and appear at
earlier times for stars of increasing mass. We postulate that no severe
compositional changes resulting from the fallback material should be expected
near peak for a wide range of stellar masses and, as such, are unable to
explain the extreme helium-to-hydrogen line ratios observed in some TDEs. On
the other hand, the resulting compositional changes could help explain the
presence of nitrogen-rich features, which are currently only detected after
peak. When combined with the shape of the light curve, the time evolution of
the composition of the fallback material provides a clear method to help
constrain the nature of the disrupted star. This will enable a better
characterization of the event by helping break the degeneracy between the mass
of the star and the mass of the black hole when fitting tidal disruption light
curves.Comment: 14 pages, 14 figures. Submitted to Ap
Reporting quality of music intervention research in healthcare: A systematic review
INTRODUCTION:
Concomitant with the growth of music intervention research, are concerns about inadequate intervention reporting and inconsistent terminology, which limits validity, replicability, and clinical application of findings.
OBJECTIVE:
Examine reporting quality of music intervention research, in chronic and acute medical settings, using the Checklist for Reporting Music-based Interventions. In addition, describe patient populations and primary outcomes, intervention content and corresponding interventionist qualifications, and terminology.
METHODS:
Searching MEDLINE, PubMed, CINAHL, HealthSTAR, and PsycINFO we identified articles meeting inclusion/exclusion criteria for a five-year period (2010-2015) and extracted relevant data. Coded material included reporting quality across seven areas (theory, content, delivery schedule, interventionist qualifications, treatment fidelity, setting, unit of delivery), author/journal information, patient population/outcomes, and terminology.
RESULTS:
Of 860 articles, 187 met review criteria (128 experimental; 59 quasi-experimental), with 121 publishing journals, and authors from 31 countries. Overall reporting quality was poor with <50% providing information for four of the seven checklist components (theory, interventionist qualifications, treatment fidelity, setting). Intervention content reporting was also poor with <50% providing information about the music used, decibel levels/volume controls, or materials. Credentialed music therapists and registered nurses delivered most interventions, with clear differences in content and delivery. Terminology was varied and inconsistent.
CONCLUSIONS:
Problems with reporting quality impedes meaningful interpretation and cross-study comparisons. Inconsistent and misapplied terminology also create barriers to interprofessional communication and translation of findings to patient care. Improved reporting quality and creation of shared language will advance scientific rigor and clinical relevance of music intervention research
The Landscape of Galaxies Harboring Changing-Look Active Galactic Nuclei in the Local Universe
We study the properties of the host galaxies of Changing-Look Active Galactic
Nuclei (CL AGNs) with the aim of understanding the conditions responsible for
triggering CL activity. We find that CL AGN hosts primarily reside in the
so-called green valley that is located between spiral-like star-forming
galaxies and dead ellipticals, implying that CL AGNs are activated during
distinct periods of quenching and galaxy transformation processes. CL AGN hosts
have low galaxy asymmetry indicators, suggesting that secular evolutionary
processes (the influence of bars and spirals, and possibly minor mergers) might
be the primary mechanism for transporting gas to the vicinity of the
supermassive black hole (SMBH) rather than major mergers. Similar to tidal
disruption events (TDEs) and highly variable AGNs, we find that CL AGN hosts
are associated with SMBHs residing in high density pseudo-bulges and appear to
overlap most significantly with the population of low-ionization nuclear
emission-line region (LINER) galaxies. As such, CL AGN are likely fueled by
strong episodic bursts of accretion activity, which appear to take place
preferentially as the amount of material accessible for star formation and
accretion dwindles. We also identify that CL AGN hosts are characterized by
either large S\'ersic indices or high bulge fractions, which suggests a simple
metric for identifying candidates for spectroscopic follow-up observations in
forthcoming synoptic surveys.Comment: 17 pages, 9 figures. Accepted to ApJ Letters. Revised version
includes an expanded discussion on asymmetry measurements and galaxy
disturbance
LimberJack.jl: auto-differentiable methods for angular power spectra analyses
We present LimberJack.jl, a fully auto-differentiable code for cosmological analyses of 2 point auto- and cross-correlation measurements from galaxy clustering, CMB lensing and weak lensing data written in Julia. Using Julia’s auto-differentiation ecosystem, LimberJack.jl can obtain gradients for its outputs an order of magnitude faster than traditional finite difference methods. This makes LimberJack.jl greatly synergistic with gradient-based sampling methods, such as Hamiltonian Monte Carlo, capable of efficiently exploring parameter spaces with hundreds of dimensions. We first prove LimberJack.jl’s reliability by reanalysing the DES Y1 3×2-point data. We then showcase its capabilities by using a O(100) parameters Gaussian Process to reconstruct the cosmic growth from a combination of DES Y1 galaxy clustering and weak lensing data, eBOSS QSO’s, CMB lensing and redshift-space distortions. Our Gaussian process reconstruction of the growth factor is statistically consistent with the ΛCDM Planck 2018 prediction at all redshifts. Moreover, we show that the addition of RSD data is extremely beneficial to this type of analysis, reducing the uncertainty in the reconstructed growth factor by 20% on average across redshift. LimberJack.jl is a fully open-source project available on Julia’s general repository of packages and GitHub
Cost of non-alcoholic steatohepatitis in Europe and the USA: the GAIN study
Background & Aims: Non-alcoholic steatohepatitis (NASH) leads to cirrhosis and is associated with a substantial socioeco-
nomic burden, which, coupled with rising prevalence, is a growing public health challenge. However, there are few real-world
data available describing the impact of NASH.
Methods: The Global Assessment of the Impact of NASH (GAIN) study is a prevalence-based burden of illness study across
Europe (France, Germany, Italy, Spain, and the UK) and the USA. Physicians provided demographic, clinical, and economic
patient information via an online survey. In total, 3,754 patients found to have NASH on liver biopsy were stratified by fibrosis
score and by biomarkers as either early or advanced fibrosis. Per-patient costs were estimated using national unit price data
and extrapolated to the population level to calculate the economic burden. Of the patients, 767 (20%) provided information on
indirect costs and health-related quality of life using the EuroQOL 5-D (EQ-5D; n = 749) and Chronic Liver Disease Ques-
tionnaire – Non-Alcoholic Fatty Liver Disease (CLDQ-NAFLD) (n = 723).
Results: Mean EQ-5D and CLDQ-NAFLD index scores were 0.75 and 4.9, respectively. For 2018, the mean total annual per
patient cost of NASH was V2,763, V4,917, and V5,509 for direct medical, direct non-medical, and indirect costs, respectively.
National per-patient cost was highest in the USA and lowest in France. Costs increased with fibrosis and decompensation,
driven by hospitalisation and comorbidities. Indirect costs were driven by work loss.
Conclusions: The GAIN study provides real-world data on the direct medical, direct non-medical, and indirect costs asso-
ciated with NASH, including patient-reported outcomes in Europe and the USA, showing a substantial burden on health
services and individuals
Rethinking Thorne-\.Zytkow Object Formation: The Fate of X-ray Binary LMC X-4 and Implications for Ultra-long Gamma-ray Bursts
We present a start-to-end simulation aimed at studying the long-term fate of
high mass X-ray binaries and whether a Thorne-\.Zytkow object (T\.ZO) might
ultimately be produced. We analyze results from a 3D hydrodynamical simulation
that models the eventual fate of LMC X-4, a compact high mass X-ray binary
system, after the primary fills its Roche lobe and engulfs the neutron star
companion. We discuss the outcome of this engulfment within the standard
paradigm of T\.ZO formation. The post-merger angular momentum content of the
stellar core is a key ingredient, as even a small amount of rotation can break
spherical symmetry and produce a centrifugally supported accretion disk. Our
findings suggest the inspiraling neutron star, upon merging with the core, can
accrete efficiently via a disk at high rates (), subsequently collapsing into a black hole and triggering a bright
transient with a luminosity and duration typical of an ultra-long gamma-ray
burst. We propose that the canonical framework for T\.ZO formation via common
envelope needs to be revised, as the significant post-merger accretion feedback
will unavoidably unbind the vast majority of the surrounding envelope
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