A search for high energy neutrinos from SN 1987A,the Carb,Hercules X-1, and Cygnus X-3 with the Fréjus detector

With the Fréjus detector we studied four astrophysical point-like sources by using \(v_e (\bar v_e )\) and \(v_\mu (\bar v_\mu )\) interactions in the detector and \(v_\mu (\bar v_\mu )\) interactions in the surrounding rock. No excess of events was found. Therefore upper limits of neutrino fluxes and source luminositics are quoted. These limits confirm results from other experiments. In addition new limits are presented for spectral indices above 3.     

Inclusive cross sections for gluon production in collision of two projectiles on two targets in the BFKL approach

We describe the Resummino package, a C++ and Fortran program dedicated to precision calculations in the framework of gaugino and slepton pair production at hadron colliders. This code allows to calculate transverse-momentum and invariant-mass distributions as well as total cross sections by combining the next-to-leading order predictions obtained by means of perturbative QCD with the resummation of the large logarithmic contributions arising in the small transverse-momentum region and close to the production threshold. The results computed in this way benefit from reduced theoretical uncertainties, compared to a pure next-to-leading order approach as currently employed in the experimental analyses searching for sleptons and gauginos at hadron colliders. This is illustrated by using Resummino in the context of a typical supersymmetric benchmark point dedicated to superpartner searches at the Large Hadron Collider.     

PENTATRAP: a novel cryogenic multi-Penning-trap experiment for high-precision mass measurements on highly charged ions

The novel five-Penning-trap mass spectrometer Pentatrap is developed at the Max-Planck-Institut für Kernphysik (MPIK), Heidelberg. Ions of interest are long-lived highly charged nuclides up to bare uranium. Pentatrap aims for an accuracy of a few parts in 10¹² for mass ratios of mass doublets. A physics program for Pentatrap includes Q-value measurements of β-transitions relevant for neutrino physics, stringent tests of quantum electrodynamics in the regime of extreme electric fields, and a test of special relativity. Main features of Pentatrap are an access to a source of highly charged ions, a multi-trap configuration, simultaneous measurements of frequencies, a continuous precise monitoring of magnetic field fluctuations, a fast exchange between different ions, and a highly sensitive cryogenic non-destructive detection system. This article gives a motivation for the new mass spectrometer Pentatrap, presents its experimental setup, and describes the present status.     

Magnetic hyperfine field at Cr site in AgCrO2 given by Perturbed angular correlations

This work presents an electric field gradient and magnetic hyperfine field study, in the AgCrO₂ multiferroic with triangular spin lattice. The temperature dependence of the electric field gradient (efg) and magnetic hyperfine field (mhf) at Cr site was studied at isolde via perturbed angular correlation measurements with the ¹¹¹In probe, at room temperature and below the Néel temperature (T?≤?21 K) down to 12 K. The results show the presence of two distinct local environments. One axial symmetric efg with a very low mhf, and a non axially symmetric efg with a much higher one. The temperature dependences of mhf magnitude and of the angle between the mhf and the principle component of the efg are investigated.     

Astroparticle physics with high energy neutrinos: from AMANDA to IceCube

Kilometer-scale neutrino detectors such as IceCube are discovery instruments covering nuclear and particle physics, cosmology and astronomy. Examples of their multidisciplinary missions include the search for the particle nature of dark matter and for additional small dimensions of space. In the end, their conceptual design is very much anchored to the observational fact that Nature produces protons and photons with energies in excess of 10²⁰ eV and 10¹³ eV, respectively. The puzzle of where and how Nature accelerates the highest energy cosmic particles is unresolved almost a century after their discovery. The cosmic ray connection sets the scale of cosmic neutrino fluxes. In this context, we discuss the first results of the completed AMANDA detector and the science reach of its extension, IceCube. Similar experiments are under construction in the Mediterranean. Neutrino astronomy is also expanding in new directions with efforts to detect air showers, acoustic and radio signals initiated by super-EeV neutrinos. The outline of this review is as follows:

Introduction

Why kilometer-scale detectors?

Cosmic neutrinos associated with the highest energy cosmic rays

High energy neutrino telescopes: methodologies of neutrino detection

High energy neutrino telescopes: status

     

Spezifischer Energieverlust von schweren Ionen in Aluminium,Silber und Gold

Using a Cf²⁵²-fission source and two semiconductor detectors in 180°-position the specific energy loss of heavy ions in A1-, Ag-, and Au-foils was measured. The agreement with the results ofMoak andBrown, and ofKahn andForgue is better than 15%. The energy loss predicted byLindhard is 10–25% lower than the measured values. A better agreement — especially for absorbers with low atomic numberZ — is achieved by a semiempirical formula proposed byMünzel.     

MCPLOTS: a particle physics resource based on volunteer computing

The mcplots.cern.ch web site (mcplots) provides a simple online repository of plots made with high-energy-physics event generators, comparing them to a wide variety of experimental data. The repository is based on the hepdata online database of experimental results and on the rivet Monte Carlo analysis tool. The repository is continually updated and relies on computing power donated by volunteers, via the lhc@home 2.0 platform.     

Simulating spin-\frac{3}{2} particles at colliders

Support for interactions of spin- $\frac{3}{2}$ particles is implemented in the FeynRules and ALOHA packages and tested with the MadGraph 5 and CalcHEP event generators in the context of three phenomenological applications. In the first, we implement a spin- $\frac{3}{2}$ Majorana gravitino field, as in local supersymmetric models, and study gravitino and gluino pair-production. In the second, a spin- $\frac{3}{2}$ Dirac top-quark excitation, inspired from compositeness models, is implemented. We then investigate both top-quark excitation and top-quark pair-production. In the third, a general effective operator for a spin- $\frac{3}{2}$ Dirac quark excitation is implemented, followed by a calculation of the angular distribution of the s-channel production mechanism.     

On the energy-dependence of the mass-operator and the „effective-interaction“

We consider a microscopic system \(\mathfrak{S}\) coupled to a bath \(\mathfrak{B}\) and establish a non-Markoffian master equation for the reduced statistical operator of \(\mathfrak{S}\) , valid in theBorn approximation. Discussing in detail theBorn approximation we find as a general condition for its validity that a certain “strength function” should not degenerate to one or more extremly sharp and high lines.     

Messung der Oberflächenspannung der flüssigen Alkalimetalle im Ultra-Hochvakuum

The surface tension of highly purified, liquid alkali metals and its temperature dependence have been measured under ultra-high-vacuum conditions. The results obtained for sodium agree with those ofAddison andTaylor as well as with theoretical values given byStratton andZadumkin, whereas the results on K, Rb and Cs are different from all values obtained hitherto by others. The temperature dependence of surface tension of all alkalis follows theoretical predictions. There is no observable influence of Ar and O₂ on the surface tension up to 10^?3 Torr.     

The determination by an independent method ofP k electron capture probabilities in133Ba and139Ce decays gamma decay of133Ba

The electron capture decays of¹³³Ba (10.4 y) and¹³⁹Ce (140 d) were investigated with high resolution Ge(Li) detectors. By x-ray — γ-ray coincidences values of the quantityP _k ω _k ? _k for various transitions in the decay of¹³³Ba and¹³⁹Ce are obtained. The factor ω _k ? _k was measured independently by means ofK-conversion electron-K x-ray coincidences and was then used to determineP _k , theK-capture probability. The independent measurement of the product ω _k ? _k , together with recent accurate values of ω _k , provides a new method for the accurate calibration of semiconductor x-ray detectors. In the decay of¹³⁹Ce, a value ofP _k =0.78±0.03 is found (where the error represents twice the standard deviation) from whichQ _ec =326 _?30 ⁺⁷⁰ keV to the¹³⁹La ground-state is found by use of theory. In¹³³Ba decay, values are found ofP _k 1=0.72±0.04 for theEC transition to the 437 keV level in¹³³Cs,P _k 2=0.80±0.07 to the 384 keV level, and from an independent measurement, the ratioP _k 1/P _k 2=0.87±0.07. From these results the ground-state value ofQ _ec =522 _?10 ⁺²⁰ keV is derived from theory for¹³³Ba decay. The gamma spectrum of¹³³Ba also was remeasured. From the present gamma intensities and previous conversion electron intensities, new values forK-shell conversion coefficients are obtained. Previously reported γ-rays at 35 and 391 keV are not confirmed.     

Das kritische Magnetfeld Hc∥ von dünnen supraleitenden Filmen

Thin superconducting films in a surface parallel magnetic field are considered, assuming that the order parameter is constant in space. Without any further restrictions on the film thickness,a, an equation for the critical field is derived. In the clean limit, this equation is valid only in the vicinity of T_c, but in the dirty limit it is valid for all temperatures. Our results, for specular reflection, are identical with those obtained byThompson andBaratoff. But for not too thin films we find essential differences between the results for specular and for diffus reflection. For very thin films (a?v/2πT _c), considered in detail byde Gennes andTinkham and byShapoval, our results are in agreement with those obtained byShapoval. In the opposit limit (a?v/2π T _c), the most essential corrections to the Ginzburg-Landau result obtained byLüders are rederived.     

The measured energy loss of high energy electrons in aluminum

The energy distributions of electrons of about 54, 75 and 97 Mev have been measured before and after passing through aluminum absorbers of thicknesses ranging from 0.730 to 5.574 gm/cm². The electrons were accelerated by the LINAC of the Naval Postgraduate School. The most probable energy losses agree with the theory ofBlunck andWestphal for all thicknesses; the half widths of the distributions agree with theory except for large thicknesses, where they exceed the theoretical values. These results are in contrast to those ofBreuer, which indicate systematically large half widths and most probable energy losses which are greater than theory for thicknesses greater than about 2 gm/cm². Since our data agree with those ofBreuer, the difference occurs in the treatment of the theory.     

Determination of relaxation times for iron ions from Mössbauer data

An analysis is made of the experimental results ofBruckner et al., in terms of the relaxation model ofvan der Woude andDekker, and a comparison is made with Wegener's analysis. The two approaches lead in principle to relaxation parameters independent ofH/T and a discrepancy reported byWegener does not exist.     

Complete mass spectra ofq\bar q andQ\bar q mesons with improved Bethe-Salpeter dynamics of confinementmesons with improved Bethe-Salpeter dynamics of confinement

The Bethe-Salpeter (bs) dynamics of harmonic confinement developed byanm and collaborators over the last three years and already applied with considerable experimental success to various hadron spectra and coupling structures has been significantly improved through (i) a more exact treatment of a certain momentum-dependent operator \(\hat Q_q \) appearing in thebs equation, using the techniques of SO (2, 1) Lie algebra, and (ii) a sharpened definition of theqcd Coulomb term, so as to yield unambiguous values for different flavour sectors. The resulting mass spectra of light \((q\bar q)\) meson towers and semi-heavy \((Q\bar q)\) quarkonia which are most sensitive to the improved treatment of \(\hat Q_q \) , reveal excellent agreement with experiment, one in which only slight changes in the reduced spring constant \((\tilde \omega )\) and quark masses (m _q ) over the earlier parametrizations are involved. These changes are however found to have a negligible effect on the (already good) numerical values of the other predictions (electroweak and pionic couplings) depending on the \(q\bar q\) andqqq wave functions. A critical assessment of the strong and weak points of this method is madevis-a-vis other related approaches.     

Mechanoluminescence of coloured KCl crystals

The gamma-irradiated KCl crystals exhibit mechanoluminescence during elastic, plastic and fracture deformation. The mechanoluminiscence (ml) intensity varies linearly with the number of newly-created dislocations and decreases with successive application and release of uniaxial pressure. The totalml intensity increases with applied pressure as well as with the temperature of the crystals. On the basis of the movement of the dislocations, the pressure and temperature dependence ofml is discussed.     

Polynomial behaviour of scattering amplitudes at fixed momentum transfer in theories with local observables

It is shown that, in theories of exactly localized observables, of the type proposed byAraki andHaag, the reaction amplitude for two particles giving two particles is polynomially bounded ins for fixed momentum transfert<0. The proof does not need observables localized in space-time regions of arbitrarily small volume, but uses relativistic invariance in an essential way. It is given for the case of spinless neutral particles, but is easily extendable to all cases of charge and spin. The proof can also be generalized to the case of particles described by regularized products $$\int {\varphi (x_1 ,..., x_n ) \phi _1 } (x - x_1 ) ... \phi _n (x - x_n )dx_1 ...dx_n $$ ofWightman orJaffe fields.