1,846 research outputs found
QCD critical end point from a realistic PNJL model
With parameters fixed by critical temperature and equation of state at zero
baryon chemical potential, a realistic Polyakov--Nambu--Jona-Lasinio (rPNJL)
model predicts a critical end point of chiral phase transition at . The extracted freeze-out line from heavy ion
collisions is close to the chiral phase transition boundary in the rPNJL model,
and the kurtosis of baryon number fluctuations from the rPNJL
model along the experimental freeze-out line agrees well with the BES-I
measurement. Our analysis shows that the dip structure of measured
is determined by the relationship between the freeze-out line
and chiral phase transition line at low baryon density region, and the peak
structure can be regarded as a clean signature for the existence of CEP.Comment: 8 papges, proceedings of QCD@Work 201
Corrections to holographic entanglement plateau
We investigate the robustness of the Araki-Lieb inequality in a
two-dimensional (2D) conformal field theory (CFT) on torus. The inequality
requires that is nonnegative, where
is the thermal entropy and , are the entanglement
entropies. Holographically there is an entanglement plateau in the BTZ black
hole background, which means that there exists a critical length such that when
the inequality saturates . In thermal AdS
background, the holographic entanglement entropy leads to for
arbitrary . We compute the next-to-leading order contributions to in the large central charge CFT at both high and low temperatures. In both
cases we show that is strictly positive except for or
. This turns out to be true for any 2D CFT. In calculating the single
interval entanglement entropy in a thermal state, we develop new techniques to
simplify the computation. At a high temperature, we ignore the finite size
correction such that the problem is related to the entanglement entropy of
double intervals on a complex plane. As a result, we show that the leading
contribution from a primary module takes a universal form. At a low
temperature, we show that the leading thermal correction to the entanglement
entropy from a primary module does not take a universal form, depending on the
details of the theory.Comment: 32 pages, 8 figures; V2, typos corrected, published versio
Using neutron scattering to study the structure and flexibility of hexadecyltrimethylammonium dichlorobenzoate and related micelles
Certain ionic surfactants can self-assemble in aqueous solutions into giant flexible wormlike micelles that behave similarly to semi-flexible polymers. Small angle neutron scattering (SANS) has been used to study the sizes and flexibilities of these micelles. By allowing the probing of shorter length scales than light scattering, SANS is clearly preferable for determining micellar persistence lengths directly. SANS curves were fit to a series of micellar models to get information on persistence lengths, contour lengths and cross-sectional radii. The impact of different tail lengths, head groups, counterions, and varying ionic strengths were studied. Counterions have major effects on micellar size and flexibility. For nonpenetrating counterions, such as chloride and bromide, the micellar size and flexibility increase as the concentrations of the counterion increase (by adding the common-ion salt), with bromide having the larger effect compared to chloride. For penetrating counterions, such as salicylate, 26dichlorobenzoate, and tosylate, the micellar size and flexibility highly depend on the structure of the counterions. Mixed counterions (penetrating and non penetrating) have also been studied, and the micellar size found to increase dramatically in mixed counterions systems
The Challenges in Modeling Human Performance in 3D Space with Fitts’ Law
With the rapid growth in virtual reality technologies, object interaction is
becoming increasingly more immersive, elucidating human perception and leading
to promising directions towards evaluating human performance under different
settings. This spike in technological growth exponentially increased the need
for a human performance metric in 3D space. Fitts' law is perhaps the most
widely used human prediction model in HCI history attempting to capture human
movement in lower dimensions. Despite the collective effort towards deriving an
advanced extension of a 3D human performance model based on Fitts' law, a
standardized metric is still missing. Moreover, most of the extensions to date
assume or limit their findings to certain settings, effectively disregarding
important variables that are fundamental to 3D object interaction. In this
review, we investigate and analyze the most prominent extensions of Fitts' law
and compare their characteristics pinpointing to potentially important aspects
for deriving a higher-dimensional performance model. Lastly, we mention the
complexities, frontiers as well as potential challenges that may lay ahead.Comment: Accepted at ACM CHI 2021 Conference on Human Factors in Computing
Systems (CHI '21 Extended Abstracts
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