The fraction of Bose-Einstein condensed triplons in TlCuCl3 from magnetization M(T,H)-data

In this study we calculate the fraction of condensed magnetic quasiparticles of TlCuCl3 from magnetization M(T,H)-data. It is independent of the direction of the magnetic field and slightly decreases with increasing magnetic field.Comment: 8 pages, 10 figure

Defect propagation in one-, two-, and three-dimensional compounds doped by magnetic atoms

Inelastic neutron scattering experiments were performed to study manganese(II) dimer excitations in the diluted one-, two-, and three-dimensional compounds CsMn(x)Mg(1-x)Br(3), K(2)Mn(x)Zn(1-x)F(4), and KMn(x)Zn(1-x)F(3) (x<0.10), respectively. The transitions from the ground-state singlet to the excited triplet, split into a doublet and a singlet due to the single-ion anisotropy, exhibit remarkable fine structures. These unusual features are attributed to local structural inhomogeneities induced by the dopant Mn atoms which act like lattice defects. Statistical models support the theoretically predicted decay of atomic displacements according to 1/r**2, 1/r, and constant (for three-, two-, and one-dimensional compounds, respectively) where r denotes the distance of the displaced atoms from the defect. The observed fine structures allow a direct determination of the local exchange interactions J, and the local intradimer distances R can be derived through the linear law dJ/dR.Comment: 22 pages, 5 figures, 2 table

Enzyme-linked immunosorbent assay for urinary albumin at low concentrations

We describe an enzyme-linked immunosorbent assay (ELISA) for urinary albumin. It requires only commercially available reagents, can detect as little as 16 micrograms of albumin per liter, and analytical recovery ranges from 92 to 116%. The assay is simple, rapid, and inexpensive. Albumin excretion was 6.2 (SD 4.1) mg/24 h in healthy subjects (n = 40), 14.7 (SD 7.2) mg/24 h in albumin-test-strip-negative Type I diabetics (n = 11), and 19.7 (SD 16.2) mg/24 h in patients with essential hypertension (n = 12)

Hemodynamic and inotropic effects of endothelin-1 in vivo

Endothelin-1 (ET-1) is known to have strong vasoactive properties. Contradictory results have been reported with regard to its inotropic effects. This study examined the dose-dependent (500, 1000, 2500, 5000 and 10,000 ng ET-1/kg vs. NaCl controls) hemodynamic and inotropic effects of ET-1 in 53 open-chest rats during and after a 7-min infusion. Besides measurements in the intact circulation the myocardial function was examined by isovolumic registrations independent of peripheral vascular effects. A transient ET-1 induced (500, 1000, 2500, 5000 ng ET-1/kg) decrease of the left ventricular systolic pressure (LVSP) and the mean aortic pressure (AoPmean) was followed by a dose-related rise of these pressures (LVSP: -1%, -1%, +8%, +16% vs. preinfusion values; AoPmean: -11%, +9%, +39%, +52%). Heart rate (HR) was not influenced by ET-1. Due to the dose-dependent decrease of the stroke volume (SV) the cardiac output (CO) was reduced (CO: -8%, -23%, -40%, -50%). After an initial vasodilatation ET-1 elevates the total peripheral resistance (TPR: -1%, +49%, +139%, +215%) dose-dependently. 10,000 ng ET-1/kg was a lethal dose resulting in cardiac failure within minutes (low output). Since the maximum of the isovolumic LVSP (peak LVSP) and the corresponding dP/dtmax (peak dP/dtmax) were unchanged under ET-1, the isovolumic measurements do not indicate a positive inotropic effect of ET-1 in vivo in contrast to published results of in vitro experiments. It may be possible that a direct positive inotropic effect of ET-1 observed in in vitro studies is counterbalanced in vivo by an indirect negative inotropic effect due to the coronary-constrictive effect of ET-1

Bounds on R-parity violating supersymmetric couplings from leptonic and semi-leptonic meson decays

We present a comprehensive update of the bounds on R-Parity violating supersymmetric couplings from lepton-flavour- and lepton-number-violating decay processes. We consider tau and mu decays as well as leptonic and semi-leptonic decays of mesons. We present several new bounds resulting from tau, eta and Kaon decays and correct some results in the literature concerning B-meson decays.Comment: 30 pages; changed title, updated some bounds from the literature from different references, added reference

Supersymmetric NLO QCD Corrections to Resonant Slepton Production and Signals at the Tevatron and the LHC

We compute the total cross section and the transverse momentum distribution for single charged slepton and sneutrino production at hadronic colliders including NLO supersymmetric and non-supersymmetric QCD corrections. The supersymmetric QCD corrections can be substantial. We also resum the gluon transverse momentum distribution and compare our results with two Monte Carlo generators. We compute branching ratios of the supersymmetric decays of the slepton and determine event rates for the like-sign dimuon final state at the Tevatron and at the LHC.Comment: 14 pages, LaTeX, 8 figures, uses REVTex

Dimensional reduction by pressure in the magnetic framework material CuF2_{2}(D2_{2}O)2_{2}pyz: from spin-wave to spinon excitations

Metal organic magnets have enormous potential to host a variety of electronic and magnetic phases that originate from a strong interplay between the spin, orbital and lattice degrees of freedom. We control this interplay in the quantum magnet CuF$_2$(D$_2$O)$_2$pyz by using high pressure to drive the system through a structural and magnetic phase transition. Using neutron scattering, we show that the low pressure state, which hosts a two-dimensional square lattice with spin-wave excitations and a dominant exchange coupling of 0.89 meV, transforms at high pressure into a one-dimensional spin-chain hallmarked by a spinon continuum and a reduced exchange interaction of 0.43 meV. This direct microscopic observation of a magnetic dimensional crossover as a function of pressure opens up new possibilities for studying the evolution of fractionalised excitations in low dimensional quantum magnets and eventually pressure-controlled metal--insulator transitions

Probing the Top-Quark Electric Dipole Moment at a Photon Linear Collider

We probe the top-quark electric dipole moment (EDM) in top-quark pair production via photon-photon fusion at a photon linear collider. We show how linearly-polarized photon beams can be used to extract information on the top-quark EDM without the use of complicated angular correlations of top-quark decay products. If the luminosity of the laser back-scattered photon-photon collisions is comparable to that of the $e^+e^-$ collisions, then the measurement of the top-quark EDM obtained by counting top-quark-production events in photon fusion can be as accurate as the measurement obtained by studying the $t\bar{t}$ decay correlations in $e^+e^-$ collisions using a perfect detector.Comment: Latex, 11 pages, 1 figure (not included). One compressed postscript file of the paper available at ftp://ftp.kek.jp/kek/preprints/TH/TH-443/kekth443.ps.g

High-resolution wide-band Fast Fourier Transform spectrometers

We describe the performance of our latest generations of sensitive wide-band high-resolution digital Fast Fourier Transform Spectrometer (FFTS). Their design, optimized for a wide range of radio astronomical applications, is presented. Developed for operation with the GREAT far infrared heterodyne spectrometer on-board SOFIA, the eXtended bandwidth FFTS (XFFTS) offers a high instantaneous bandwidth of 2.5 GHz with 88.5 kHz spectral resolution and has been in routine operation during SOFIA's Basic Science since July 2011. We discuss the advanced field programmable gate array (FPGA) signal processing pipeline, with an optimized multi-tap polyphase filter bank algorithm that provides a nearly loss-less time-to-frequency data conversion with significantly reduced frequency scallop and fast sidelobe fall-off. Our digital spectrometers have been proven to be extremely reliable and robust, even under the harsh environmental conditions of an airborne observatory, with Allan-variance stability times of several 1000 seconds. An enhancement of the present 2.5 GHz XFFTS will duplicate the number of spectral channels (64k), offering spectroscopy with even better resolution during Cycle 1 observations.Comment: Accepted for publication in A&A (SOFIA/GREAT special issue

Dependence of the BEC transition temperature on interaction strength: a perturbative analysis

We compute the critical temperature T_c of a weakly interacting uniform Bose gas in the canonical ensemble, extending the criterion of condensation provided by the counting statistics for the uniform ideal gas. Using ordinary perturbation theory, we find in first order $(T_c-T_c^0)/T_c^0 = -0.93 a\rho^{1/3}$, where T_c^0 is the transition temperature of the corresponding ideal Bose gas, a is the scattering length, and $\rho$ is the particle number density.Comment: 14 pages (RevTeX