The diagonal and off-diagonal quark number susceptibility of high temperature and finite density QCD

We study the quark number susceptibility of the hot quark-gluon plasma at zero and non-zero quark number density, using lattice Monte Carlo simulations of an effective theory of QCD, electrostatic QCD (EQCD). Analytic continuation is used to obtain results at non-zero quark chemical potential. We measure both flavor singlet (diagonal) and non-singlet (off-diagonal) quark number susceptibilities. The diagonal susceptibility approaches the perturbative result above 20T_c, but below that temperature we observe significant deviations. The results agree well with 4d lattice data down to temperatures 2T_c. The off-diagonal susceptibility is more prone to statistical and systematic errors, but the results are consistent with perturbation theory already at 10T_c.Comment: 21 pages, 8 figures. Published version, references added, conclusions unchange

Relativistic charged particle ejection from optical lattice

We have analyzed relativistic (∼ MeV) electron ejection from potential channels of standing laser wave taking into account both rapid and averaged oscillations within the region of declining field of standing wave. We show that only a few last rapid oscillations can define transverse speed and, therefore, angle at which a particle leaves standing wave. This conclusion might drastically simplify numerical simulations of charged particles channeling and accompanying radiation in crossed lasers field. Moreover, it might provide a valuable information for estimation of charged particle beams parameters after their interaction with finite standing wave

On a quantum particle in laser channels

In this paper the effective potential describing interaction of a scalar quantum particle with arbitrary nonuniform laser field is derived for a wide spectrum of the particle energies. The presented method allows to take into account all the features of the effective potential for a scalar particle. The derived expression for effective potential for quantum particle has the same form as the one presented earlier for a classical particle. A special case for channeling of a quantum particle as well as accompanying channeling radiation in a field formed by two crossed plane laser waves is considered. It is shown that relativistic particles moving near the laser channel bottom should be examined as quantum ones at both arbitrarily large longitudinal energies and laser fields of accessible intensities

Spectral distribution of SPARC photoinjector electrons

SPARC is a photo-injector for production of high-brightness lowemittance electron beams to drive a FEL experiment in various configurations, including SASE-FEL radiation of 1–10nm (SPARCX project). Due to a high-brightness source, the SPARC facility can be used to study the physics of ultrashort beams, plasma-wave based acceleration, production of X-rays by means of Compton backscattering, channeling of electron beams and other experiments. The initial process of electron beam generation inside the RF gun determines the main parameters of the electron beam. Interaction of electrons with high-frequency laser beam leads to modulation of the electron beam. In this paper we present electron beam spectral distribution for SPARC photoinjector parameters. The estimate of electron beam energy loss for such electron distribution also is given

Legionellapreventie: betere naleving Waterleidingwet nodig

Ongeveer 20 procent van de zorginstellingen en zwembaden heeft in 2005 te maken gehad met een legionellabesmetting in de leidingwaterinstallatie. Dit gold ook voor 5 procent van de hotels en campings. Vooral in zorginstellingen kan Legionella in de waterleidingen gevaarlijk zijn, omdat de mensen hier vaak een zwakkere gezondheid hebben. Circa 90% van de instellingen leeft niet alle wettelijk voorgeschreven preventiemaatregelen volledig na. Bij hercontrole is echter een groot deel van de problemen opgelost. Dit toont de effectiviteit en het belang van de controles: eenmaal op de hoogte van de risico’s zijn de eigenaren meestal bereid de nodige aanpassingen te doen. Het aantal collectieve leidingwaterinstallaties met Legionella nam tussen 2000 en 2006 niet duidelijk af. Een betere naleving van de legionellapreventie regelgeving en installatievoorschriften leidt naar verwachting wél tot minder Legionella in leidingwaterinstallaties. Tussen 2000 en 2006 steeg het aantal gemelde patiënten met legionellose. Een betrouwbare schatting van het aantal patiënten dat gerelateerd is aan een collectieve leidingwaterinstallatie als besmettingsbron is echter niet mogelijk

Hemisphärenspezifische Wirkung von Erythropoetin auf die GABAerge Transmission in dem prälimbischen Cortex

Hemisphärenspezifische Wirkung von Erythropoetin auf die GABAerge Transmission in dem Prälimbischen Cortex. Bei neulich entdeckten neuroprotektiven Effekt des Erythropoetins (EPO) blieb trotz nachgewiesener Wirkung von EPO auf die GABAerge Transmission, seine modulatorische Wirkungsweise fraglich. In dieser Arbeit wurde eine derartige Wirkungsweise von EPO mit Hilfe der Patch-Clamp-Technik untersucht. Dabei wurden spontaneus inhibitory postsynaptic currents von Neuronen in der II/III. Zellschicht des Prälimbischen Cortex vor und nach der EPO-Gabe abgeleitet und seitendifferenziert miteinander verglichen. Dabei wurde linkshemisphärisch die Frequenz der GABAergen Transmission eine Minute nach der EPO-Gabe für eine halbe Stunde statistisch signifikant gesteigert und rechtshemisphärisch hingegen gesenkt. Die Wirkungstypen traten intraindividuell auf, wiesen jedoch keine intrahemisphärische Ortsspezifität auf. Eine rasche Veränderung der GABAergen Transmission unter EPO wurde festgestellt

A Mach-Zehnder Interferometer for a Two-Photon Wave Packet

We propose an experiment that permits observation of the de Broglie two-photon wave packet behavior for a pair of photons, using a Mach-Zehnder interferometer. It is based on the use of pulsed lasers to generate pairs of photons via spontaneous parametric down-conversion and the post-selection of events. It differs from previous realizations by the use of a third time-correlated photon to engineer the state of the photons. The same technique can give us which-path information via an ``interaction-free'' experiment and can be used in other experiments on the foundations of quantum mechanics related to wave-particle duality and to nonlocality.Comment: Submmited for publication in Physical Review