75,607 research outputs found
Are Complex A and the Orphan Stream related?
We consider the possibility that the Galactic neutral hydrogen stream Complex
A and the stellar Orphan stream are related, and use this hypothesis to
determine possible distances to Complex A and the Orphan stream, and
line-of-sight velocities for the latter. The method presented uses our current
knowledge of the projected positions of the streams, as well as line-of-sight
velocities for Complex A, and we show that a solution exists in which the two
streams share the same orbit. If Complex A and the Orphan stream are on this
orbit, our calculations suggest the Orphan stream to be at an average distance
of 20 kpc, with heliocentric radial velocities of approximately -110 km/s.
Complex A would be ahead of the Orphan stream in the same wrap of the orbit,
with an average distance of 10 kpc, which is consistent with the distance
constraints determined through interstellar absorption line techniques.Comment: 4 pages, 2 figures; typos corrected, fig 2 and numerical predictions
updated; accepted for publication in MNRAS Letter
Lattice QCD with 12 Quark Flavors: A Careful Scrutiny
With a substantial amount of simulations, we have explored the system across
a wide range of lattice scales. We have located a lattice artifact, first order
bulk transition, have studied its properties, and found that the flavor-singlet
scalar meson mass vanishes at the critical endpoint. We will discuss the
lattice phase diagrams and the continuum limits for both a spontaneous chiral
symmetry breaking phase and an infrared conformal phase, and compare results
with other groups.Comment: 7 pages, 7 figures; Contribution to SCGT12 "KMI-GCOE Workshop on
Strong Coupling Gauge Theories in the LHC Perspective", 4-7 Dec. 2012, Nagoya
Universit
Nucleon Sigma Term and In-medium Quark Condensate in the Modified Quark-Meson Coupling Model
We evaluate the nucleon sigma term and in-medium quark condensate in the
modified quark-meson coupling model which features a density-dependent bag
constant. We obtain a nucleon sigma term consistent with its empirical value,
which requires a significant reduction of the bag constant in the nuclear
medium similar to those found in the previous works. The resulting in-medium
quark condensate at low densities agrees well with the model independent linear
order result. At higher densities, the magnitude of the in-medium quark
condensate tends to increase, indicating no tendency toward chiral symmetry
restoration.Comment: 9 pages, modified version to be publishe
- …