6,002 research outputs found
Journey to the Center of the Fuzzball
We study two-charge fuzzball geometries, with attention to the use of the
proper duality frame. For zero angular momentum there is an onion-like
structure, and the smooth D1-D5 geometries are not valid for typical states.
Rather, they are best approximated by geometries with stringy sources, or by a
free CFT. For non-zero angular momentum we find a regime where smooth fuzzball
solutions are the correct description. Our analysis rests on the comparison of
three radii: the typical fuzzball radius, the entropy radius determined by the
microscopic theory, and the breakdown radius where the curvature becomes large.
We attempt to draw more general lessons.Comment: 22 pages, 1 figur
meson production of high-energy nuclear collisions at NLO
The transverse momentum spectrum of meson in relativistic heavy-ion
collisions is studied at the next-to-leading-order (NLO) within the
perturbative QCD, where the jet quenching effect in the QGP is incorporated
with the effectively medium-modified fragmentation functions using the
higher-twist approach. We show that the theoretical simulations could give nice
descriptions of PHENIX data on meson in both and central collisions at the RHIC, and also provide numerical predictions of
spectra in central collisions with ~TeV at the
LHC. The ratios of in and in central
collisions at ~GeV are found to overlap in a wide region, which
matches well the measured ratio by PHENIX. We demonstrate that,
at the asymptotic region when the ratios of
in both and are almost determined only by
quark jets fragmentation and thus approach to the one in
scattering; in addition, the almost identical gluon (quark) contribution
fractions to and to result in a rather moderate variation of
distribution at intermediate and high region in
relative to that in ; while a slightly higher at small
in can be observed due to larger suppression of gluon
contribution fraction to as compared to the one to . The
theoretical prediction for at the LHC has also been presented.Comment: 7 pages, 8 figures, 2 typos corrected, revision for publicatio
Nuclear suppression of meson yields with large at the RHIC and the LHC
We calculate meson transverse momentum spectra in p+p collisions as
well as their nuclear suppressions in central A+A collisions both at the RHIC
and the LHC in LO and NLO with the QCD-improved parton model. We have included
the parton energy loss effect in hot/dense QCD medium with the effectively
medium-modified fragmentation functions in the higher-twist approach of
jet quenching. The nuclear modification factors of meson in central
Au+Au collisions at the RHIC and central Pb+Pb collisions at the LHC are
provided, and a nice agreement of our numerical results at NLO with the ALICE
measurement is observed. Predictions of yield ratios of neutral mesons such as
, and at large in relativistic
heavy-ion collisions are also presented for the first time.Comment: 7 pages, 8 figure
Does Bad News Spread Faster?
Bad news travels fast. Although this concept may be intuitively accepted, there has been little evidence to confirm that the propagation of bad news differs from that of good news. In this paper, we examine the effect of user perspective on his or her sharing of a controversial news story. Social media not only offers insight into human behavior but has also developed as a source of news. In this paper, we define the spreading of news by tracking selected tweets in Twitter as they are shared over time to create models of user sharing behavior. Many news events can be viewed as positive or negative. In this paper, we compare and contrast tweets about these news events among general users, while monitoring the tweet frequency for each event over time to ensure that news events are comparable with respect to user interest. In addition, we track the tweets of a controversial event between two different groups of users (i.e., those who view the event as positive and those who view it as negative). As a result, we are able to make assessments based on a single event from two different perspectives
A snapshot of compliance with the sepsis six care bundle in two acute hospitals in the West Midlands, UK
The sepsis six care bundle has been adopted by hospitals in England and Wales for the management of patients with sepsis, with the aim of increasing survival when all elements of the bundle are achieved. To assess compliance with the Sepsis Six Care Bundle in two acute NHS hospitals in the West Midlands. Adults admitted to hospital over a 24-hour period were screened for sepsis. Sepsis was identified using the Systemic Inflammatory Response (SIRS) criteria and the quick sequential organ failure assessment (qSOFA) score. Adherence to the Sepsis Six Care Bundle was assessed. 249 patients were screened and 24 patients were identified as having sepsis (9.6%). One patient received all six elements of the bundle. Compliance was highest for giving intravenous fluids (58.3%) and antibiotics (58.3%), and lowest for measuring urine output (16.7%). Further research is needed to establish the reasons for low compliance. Frankling C, Patel J, Sharif B, Melody T, Yeung J, Gao F, et al. A Snapshot of Compliance with the Sepsis Six Care Bundle in Two Acute Hospitals in the West Midlands, UK. Indian J Crit Care Med 2019;23(7):310-315
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