Photons from strange-quark annihilation in a quark-gluon plasma

We compute the energy spectrum of photons which originate from the quark-annihilation process ss¯→γg in quark-gluon plasma. The spectrum peaks at an energy Eγmax∼2ms∼400 MeV in the rest frame of the plasma. We expect one photon from the above process in the energy range of 2ms±0.25ms per hundred quark-gluon plasmas of a size R=3 fm and a lifetime τ=6 fm/c formed in nuclear collisions

Fields nonlocal in Clifford space. I. Classical Gauge-invariant nonlinear field theory

A fully gauge-invariant, Lorentz-covariant, nonlocal, and nonlinear theory, for coupled spin-½ fields, ψ, and vector fields, A, i.e., "electrons" and "photons," is constructed. The field theory is linear in the ψ fields. The nonlinearity in the A fields arises unambiguously from the requirement of gauge invariance. The coordinates are generalized to admit hypercomplex values, i.e., they are taken to be Clifford numbers. The nonlocality is limited to the hypercomplex component of the coordinates. As the size of the nonlocality is reduced toward zero, the theory goes over into the inhomogeneous Dirac theory. The nonlocality parameter corresponds to an inverse mass and induces self-regulatory properties of the propagators. It is argued that in a gauge-invariant theory a graph-by-graph convergence is impossible in principle, but it is possible that convergence may hold for the complete solution, or for sums over classes of graphs

Lower bound to limiting fields in nonlinear electrodynamics

In view of new high-precision experiments in atomic physics it seems necessary to reexamine nonlinear theories of electrodynamics. The precise calculation of electronic and muonic atomic energies has been used to determine the possible size of the upper limit Emax to the electric field strength, which has been assumed to be a parameter. This is opposed to Born's idea of a purely electromagnetic origin of the electron's mass which determines Emax. We find Emax≥1.7×1020 V/cm

Superheavy elements and an upper limit to the electric field strength

An upper limit to the electric field strength, such as that of the nonlinear electrodynamics of Born and Infeld, leads to dramatic differences in the energy eigenvalues and wave functions of atomic electrons bound to superheavy nuclei. For example, the 1s1/2 energy level joins the lower continuum at Z=215 instead of Z=174, the value obtained when Maxwell's equations are used to determine the electric field

Solution of the Dirac equation for strong external fields

The 1s bound state of superheavy atoms and molecules reaches a binding energy of -2mc2 at Z≈169. It is shown that the K shell is still localized in r space even beyond this critical proton number and that it has a width Γ (several keV large) which is a positron escape width for ionized K shells. The suggestion is made that this effect can be observed in the collision of very heavy ions (superheavy molecules) during the collision

Strangeness abundances in p¯-nucleus annihilations

Strange particle abundances in small volumes of hot hadronic gas are determined in the canonical ensemble with exact strangeness and baryon number conservation. Substantial density and baryon number dependence is found. A p¯d experiment is examined and applications to p¯-nucleus annihilations are considered

Qualität und Prävention im Gesundheitswesen

Im Rahmen ihrer Bemühungen um eine Gesundheitsreform hat Bundesgesundheitsministerin Schmidt neuerdings die Prävention als eine wichtige gesundheitspolitische Aufgabe hervorgehoben. Inwieweit ist die mangelnde Effizienz des deutschen Gesundheitswesens auf Präventionsdefizite zurückzuführen? Wirken sich die Anreizsysteme negativ auf die Gesundheitsvorsorge aus? Wie kann das Gesundheitswesen stärker präventiv ausgerichtet werden? --

Verhaltensprävention: ein Weg zur Kostendämpfung im Gesundheitswesen?

Noch in diesem Jahr beabsichtigt das Gesundheitsministerium ein Präventionsgesetz zu verabschieden. Sind durch Prävention Kosteneinsparungen im Gesundheitswesen zu erwarten? Wann ist Verhaltensprävention rational? Wo sollte die Prävention ansetzen? --

On the Proportion of Coprime Fractions in Number Fields

In this paper we determine the asymptotic density of coprime fractions in those of the reduced fractions of number fields. When ordered by norms of denominators, we count a fraction as soon as it ``appears'' for the first time and no later. The natural density of coprime fractions in the set of reduced fractions may then be computed using well-known facts about Hecke $L$-functions. Furthermore, we draw some connections to the modular group and Heegner points.Comment: 12 pages, 1 figure, 1 tabl