1,333 research outputs found
SU(3) lattice gauge theory with adjoint action at nonzero temperature
ManuscriptWe study the thermal phase diagram of pure SU(3) gauge theory with fundamental and adjoint couplings. We improve previous estimates of the position of the bulk transition line and determine the thermal deconfinement transition lines for Nt = 2,4,6, and 8. For Nt > 4 the deconfinement transition line splits cleanly away from the bulk transition line. With increasing Nt the thermal deconfinement transition lines shift to increasingly weaker coupling, joining onto the bulk transition line at increasingly larger f3a in a pattern consistent with the usual universality picture of lattice gauge theories
Thermal phase transition in mixed action SU(3) lattice gauge theory and Wilson fermion thermodynamics
ManuscriptWe study the thermal phase diagram of pure SU(3) lattice gauge theory with fundamental and adjoint couplings. We improve previous estimates of the position of the bulk transition line and determine the thermal deconfinement transition lines for Nt = 2, 4, 6, and 8. The endpoint of the bulk transition line (β_x000C_f, β_x000C_a) = (4.00(7), 2.06(8)) improves upon earlier estimates obtained using smaller lattice sizes. For Nt > 4 the deconfinement transition line splits cleanly away from the bulk transition line. With increasing Nt the thermal deconfinement transition lines shift to increasingly weaker coupling, joining onto the bulk transition line at increasingly larger _x000C_a in a pattern consistent with the usual universality picture of lattice gauge theories. We also discuss the possible consequences of an induced adjoint term from the fermionic determinant and determine this induced term numerically with a microcanonical demon method for two flavors of dynamical Wilson fermions
High-precision lattice QCD confronts experiment
Journal ArticleThe recently developed Symanzik-improved staggered-quark discretization allows unquenched lattice-QCD simulations with much smaller (and more realistic) quark masses than previously possible. To test this formalism, we compare experiment with a variety of nonperturbative calculations in QCD drawn from a restricted set of ‘‘gold-plated'' quantities. We find agreement to within statistical and systematic errors of 3% or less.We discuss the implications for phenomenology and, in particular, for heavy-quark physics
Reproduction, growth and development in two contiguously allopatric rodent species, genus Scotinomys
http://deepblue.lib.umich.edu/bitstream/2027.42/56395/1/MP151.pd
SU(3) Lattice Gauge Theory With Adjoint Action At Nonzero Temperature
We study the thermal phase diagram of pure SU(3) gauge theory with
fundamental and adjoint couplings. We improve previous estimates of the
position of the bulk transition line and determine the thermal deconfinement
transition lines for and 8. For the deconfinement
transition line splits cleanly away from the bulk transition line. With
increasing the thermal deconfinement transition lines shift to
increasingly weaker coupling, joining onto the bulk transition line at
increasingly larger in a pattern consistent with the usual
universality picture of lattice gauge theories.Comment: Talk presented by U. M. Heller at Lat94 conference, September 27 -
October 1, 1994, Bielefeld, Germany. self unwrapping postscript fil
Three Able Addresses Delivered Before the State Board of Trade at Bangor, Maine, March 25, 1902
The text of three addresses: Maine canning industry / B.M. Fernald -- Maine as a vacation state / Leroy T. Carleton -- Maine primitive and modern industry / J.W. Penney
Becoming a new neuron in the adult olfactory bulb
New neurons are continually recruited throughout adulthood in certain regions of the adult mammalian brain. How these cells mature and integrate into preexisting functional circuits remains unknown. Here we describe the physiological properties of newborn olfactory bulb interneurons at five different stages of their maturation in adult mice. Patch-clamp recordings were obtained from tangentially and radially migrating young neurons and from neurons in three subsequent maturation stages. Tangentially migrating neurons expressed extrasynaptic GABAA receptors and then AMPA receptors, before NMDA receptors appeared in radially migrating neurons. Spontaneous synaptic activity emerged soon after migration was complete, and spiking activity was the last characteristic to be acquired. This delayed excitability is unique to cells born in the adult and may protect circuits from uncontrolled neurotransmitter release and neural network disruption. Our results show that newly born cells recruited into the olfactory bulb become neurons, and a unique sequence of events leads to their functional integration
QCD thermodynamics with two flavors of Wilson quarks at N_t=6
We report on a study of hadron thermodynamics with two flavors of Wilson
quarks on 12^3x6 lattices. We have studied the crossover between the high and
low temperature regimes for three values of the hopping parameter, kappa=0.16,
0.17, and 0.18. At each of these values of kappa we have carried out spectrum
calculations on 12^3x24 lattices for two values of the gauge coupling in the
vicinity of the crossover in order to set an energy scale for our
thermodynamics calculations and to determine the critical value of the gauge
coupling for which the pion and quark masses vanish. For kappa=0.17 and 0.18 we
find coexistence between the high and low temperature regimes over 1,000
simulation time units indicating either that the equilibration time is
extremely long or that there is a possibility of a first order phase
transition. The pion mass is large at the crossover values of the gauge
coupling, but the crossover curve has moved closer to the critical curve along
which the pion and quark masses vanish, than it was on lattices with four time
slices. In addition, values of the dimensionless quantity T_c/m_rho are in
closer agreement with those for staggered quarks than was the case at N_t=4. (A
POSTSCRIPT VERSION OF THIS PAPER IS AVAILABLE BY ANONYMOUS FTP FROM
sarek.physics.ucsb.edu (128.111.8.250) IN THE FILE pub/wilson_thermo.ps)Comment: 24 page
Potts Flux Tube Model at Nonzero Chemical Potential
We model the deconfinement phase transition in quantum chromodynamics at
nonzero baryon number density and large quark mass by extending the flux tube
model (three-state, three-dimensional Potts model) to nonzero chemical
potential. In a direct numerical simulation we confirm mean-field-theory
predictions that the deconfinement transition does not occur in a baryon-rich
environment.Comment: 14 pp RevTeX, 10 Postscript figures, submitted to Phys. Rev D.
(Corrected some typographical errors.
Finite temperature QCD: progress and outstanding problems
I review recent progress in numerical simulations of finite temperature
quantum chromodynamics and discuss the status of some outstanding problems.
Included is (1) a discussion of recent results determining the temperature of
the ``phase transition'' in full QCD, (2) a scaling analysis of the Polyakov
loop variable, leading to the determination of a constituent quark free energy,
(3) studies of critical behavior near the phase transition in two-flavor QCD,
(4) a discussion of problems and new results in thermodynamic simulations with
Wilson fermions, (5) recent results in pure gauge theory with a mixed
fundamental/adjoint action, and (6) the nonperturbative determination of the
equation of state with dynamical fermions included. Finally I mention briefly
new developments in efforts to construct a phenomenology of deconfinement and
chiral symmetry restoration, namely (7) the dual superconducting model and (8)
the instanton model.Comment: Contribution to Lattice '94. 12 pages Postscrip
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