1,138 research outputs found
The effect of primordial temperature fluctuations on the QCD transition
We analyze a new mechanism for the cosmological QCD first-order phase
transition: inhomogeneous nucleation. The primordial temperature fluctuations
are larger than the tiny temperature interval, in which bubbles would form in
the standard picture of homogeneous nucleation. Thus the bubbles nucleate at
cold spots. We find the typical distance between bubble centers to be a few
meters. This exceeds the estimates from homogeneous nucleation by two orders of
magnitude. The resulting baryon inhomogeneities may affect primordial
nucleosynthesis.Comment: 6 pages, 1 figure. To appear in the Proceedings of Strong and
Electroweak Matter 2000 (SEWM2000), Marseilles, France, 14-17 June 200
The QCD phase transition in the inhomogeneous Universe
We investigate a new mechanism for the cosmological QCD phase transition:
inhomogeneous nucleation. The primordial temperature fluctuations, measured to
be , are larger than the tiny temperature interval, in
which bubbles would form in the standard picture of homogeneous nucleation.
Thus the bubbles nucleate at cold spots. We find the typical distance between
bubble centers to be a few meters. This exceeds the estimates from homogeneous
nucleation by two orders of magnitude. The resulting baryon inhomogeneities may
affect primordial nucleosynthesis.Comment: Version to appear in Phys. Rev. Lett., 4 pages, 1 figure. Difference
to heterogeneous nucleation emphasized, amplitude of temperature fluctuations
analyzed in more detail, new length scale l_heat introduced, more complicated
geometry of baryon number discussed shortly (relevant for low values of
l_heat
Cosmological Phase Transitions
Physical processes related to cosmological first-order phase transitions are
discussed and reviewed in this introductory part of dissertation. I first
describe cosmological phase transitions on a general level, concentrating on
bubble nucleation, phase change, and related phenomena. I point out that
especially the onset of a cosmological phase transition shows a universal
behavior. Then I discuss the electroweak and quark-hadron phase transitions
from a more phenomenological point of view, and present a partially
quantitative description of the different events that is believed to have taken
place during these two cosmological transitions.Comment: introductory part of Ph.D. dissertation, 53 LaTeX pages + 10 figures
not included. (Figs are available via airmail, or as a 430 kB PostScript file
via anonymous ftp at fltxc.helsinki.fi (128.214.3.11), directory /pub, file
phdfigs.ps .) HU-TFT-IR-93-
Prothrombin complex concentrates or recombinant factor VIIa are more effective than fresh-frozen plasma at lowering INR in patients with liver disease
A critical appraisal and clinical application of Kwon JO, MacLaren R. Comparison of fresh-frozen plasma, four-factor prothrombin complex concentrates, and recombinant factor VIIa to facilitate procedures in critically ill patients with coagulopathy from liver disease: a retrospective cohort study. Pharmacotherapy. 2016;36(10):1047-1054. doi: 10.1002/phar.182
B_s meson excited states from the lattice
This is a follow-up to our earlier work [Phys. Rev. D 65, 014512 (2002); Eur.
Phys. J. C 28, 79 (2003); Phys. Rev. D 69, 094505 (2004)] for the energies and
the charge (vector) and matter (scalar) distributions for S-wave states in a
heavy-light meson, where the heavy quark is static and the light quark has a
mass about that of the strange quark. We study the radial distributions of
higher angular momentum states, namely P- and D-wave states. In nature the
closest equivalent of this heavy-light system is the B_s meson.
The calculation is carried out with dynamical fermions on a 16^3 times 32
lattice with a lattice spacing of about 0.10 fm generated with the
non-perturbatively improved clover action. It is shown that several features of
the energies and radial distributions are in qualitative agreement with what
one expects from a simple one-body Dirac equation interpretation.Comment: 6 pages, poster presented at Lattice 2005 (Heavy quarks
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