Multichannel quantum-defect theory for slow atomic collisions

We present a multichannel quantum-defect theory for slow atomic collisions that takes advantages of the analytic solutions for the long-range potential, and both the energy and the angular-momentum insensitivities of the short-range parameters. The theory provides an accurate and complete account of scattering processes, including shape and Feshbach resonances, in terms of a few parameters such as the singlet and the triplet scattering lengths. As an example, results for $^{23}$Na-$^{23}$Na scattering are presented and compared close-coupling calculations.Comment: 8 pages, 3 figure

Relevansi Kajian Hukum Adat : Kasus Perkawinan Anak dari Masa ke Masa

Although the prevalence of child marriage in Indonesia is still high, adat law studies on child marriage have not received as much attention as land-related studies. This research concerning a century of political debate on child marriage proves that child marriage can only be understood if examined from the perspective of the dynamic relationship between national law, religious law, and adat law. A comparison between the results of an antrophological case study on West Java (Sundanese and Islam) and a historical case study on North Sumatra (Toba Batak and Christian) shows that the legal culture of the community and the role of religious leaders are important determinants of the acceptance or rejection of child marriage. IntisariMeskipun prevalensi perkawinan anak di Indonesia masih tinggi, studi hukum adat terhadap perkawinan anak belum mendapat perhatian sebesar studi terkait tanah. Penelitian tentang satu abad debat politik tentang perkawinan anak ini membuktikan bahwa perkawinan anak hanya dapat dipahami bila diteliti dari sudut dinamika antara hukum negara, hukum agama dan hukum adat. Perbandingan studi kasus penelitian antropologi di Jawa Barat (suku Sunda, Islam) dan studi kasus sejarah di Sumatra Utara (suku Batak Toba, Kristen) menunjukkan bahwa budaya hukum masyarakat dan peran pemimpin agama adalah faktor penting penentu penerimaan atau penolakaan perkawinan anak

Quantum-degenerate mixture of fermionic lithium and bosonic rubidium gases

We report on the observation of sympathetic cooling of a cloud of fermionic 6-Li atoms which are thermally coupled to evaporatively cooled bosonic 87-Rb. Using this technique we obtain a mixture of quantum-degenerate gases, where the Rb cloud is colder than the critical temperature for Bose-Einstein condensation and the Li cloud colder than the Fermi temperature. From measurements of the thermalization velocity we estimate the interspecies s-wave triplet scattering length |a_s|=20_{-6}^{+9} a_B. We found that the presence of residual rubidium atoms in the |2,1> and the |1,-1> Zeeman substates gives rise to important losses due to inelastic collisions.Comment: 4 pages, 3 figure

A feasibility study for the retrieval of the total column precipitable water vapour from satellite observations in the blue spectral range

We present a new algorithm for satellite retrievals of the atmospheric water vapour column in the blue spectral range. The water vapour absorption cross section in the blue spectral range is much weaker than in the red spectral range. Thus the detection limit and the uncertainty of individual observations are systematically larger than for retrievals at longer wavelengths. Nevertheless, water vapour retrievals in the blue spectral range have also several advantages: since the surface albedo in the blue spectral range is similar over land and ocean, water vapour retrievals are more consistent than for longer wavelengths. Compared to retrievals at longer wavelengths, the sensitivity for atmospheric layers close to the surface is higher due to the (typically 2 to 3 times) higher ocean albedo in the blue. Water vapour retrievals in the blue spectral range are also possible for satellite sensors, which do not measure at longer wavelengths of the visible spectral range like the Ozone Monitoring Instrument (OMI). We investigated details of the water vapour retrieval in the blue spectral range based on radiative transfer simulations and observations from the Global Ozone Monitoring Experiment 2 (GOME-2) and OMI. It is demonstrated that it is possible to retrieve the atmospheric water vapour column density in the blue spectral range over most parts of the globe. The findings of our study are of importance also for future satellite missions (e.g. Sentinel 4 and 5)

Looking at Chile’s Economic Dvelopment From an International Perspective

This paper examines the relative position of Chile through time and compared with other emerging and industrial economies, using various economic development indicators, particularly over the past two decades. It provides a descriptive analysis, without exploring causalities or testing hypotheses on the economic growth of the country, but it reveals the strengths and weaknesses that serve as the base for growth policy discussion. The comparison of economic development indicators shows that Chile is comparatively strong in macroeconomic stability, commercial and financial integration, quality of institutions, and in the progress of other structural reforms that are manifested in its well-developed capital market and private sector involvement in production. However, when it comes to quality of education, technological innovation efforts, infrastructure quality and quantity, and some social indicators, its performance is poor.

Zur Rolle und Bedeutung von Kommunikation im Nachhaltigkeitsdiskurs am Beispiel Fisch

Nachhaltigkeit - ein zukunftsfähiges Konzept, dessen Bedeutung heute angesichts der offensichtlich begrenzten Belastbarkeit von Ökosystemen zwar unumstritten ist, dessen Umsetzung sich aber dennoch oft problematisch gestaltet. Das Beispiel Fisch macht es deutlich: Probleme wie Ressourcenknappheit, illegale Fischerei, Quotenverhandlungen und Existenznöte kleiner Fischereibetriebe stehen dem Ringen um effektive Maßnahmen zur Erhaltung der Ressource Fisch gegenüber. Diesbezügliche Konflikte treten vor allem dann offen zutage, wenn das Augenmerk auf die Kommunikations- und Handlungsfähigkeit verantwortlicher Organisationen wie z.B. der EU gelegt wird. Daher werden anhand von Experteninterviews die Kommunikationen der Akteure im Nachhaltigkeitsdiskurs zum Thema Fisch untersucht, um das komplexe Beziehungsgeflecht zwischen Politik, Wirtschaft, Wissenschaft, NGOs, Medien und Verbrauchern genauer zu beleuchten und Optimierungspotenziale für die Nachhaltigkeitskommunikation zu identifizieren.<br/

Creation and manipulation of Feshbach resonances with radio-frequency radiation

We present a simple technique for studying collisions of ultracold atoms in the presence of a magnetic field and radio-frequency radiation (rf). Resonant control of scattering properties can be achieved by using rf to couple a colliding pair of atoms to a bound state. We show, using the example of 6Li, that in some ranges of rf frequency and magnetic field this can be done without giving rise to losses. We also show that halo molecules of large spatial extent require much less rf power than deeply bound states. Another way to exert resonant control is with a set of rf-coupled bound states, linked to the colliding pair through the molecular interactions that give rise to magnetically tunable Feshbach resonances. This was recently demonstrated for 87Rb [Kaufman et al., Phys. Rev. A 80:050701(R), 2009]. We examine the underlying atomic and molecular physics which made this possible. Lastly, we consider the control that may be exerted over atomic collisions by placing atoms in superpositions of Zeeman states, and suggest that it could be useful where small changes in scattering length are required. We suggest other species for which rf and magnetic field control could together provide a useful tuning mechanism.Comment: 21 pages, 8 figures, submitted to New Journal of Physic

Photoassociation spectroscopy of cold alkaline earth atoms near the intercombination line

The properties of photoassociation (PA) spectra near the intercombination line (the weak transition between $^{1}S_{0}$ and $^{3}P_{1}$ states) of group II atoms are theoretically investigated. As an example we have carried out a calculation for Calcium atoms colliding at ultra low temperatures of 1 mK, 1 $\mu$K, and 1 nK. Unlike in most current photoassociation spectroscopy the Doppler effect can significantly affect the shape of the investigated lines. Spectra are obtained using Ca--Ca and Ca--Ca$^*$ short-range {\it ab initio} potentials and long-range van der Waals and resonance dipole potentials. The similar van der Waals coefficients of ground $^{1}S_{0} + ^{1}S_{0}$ and excited $^{1}S_{0} + ^{3}P_{1}$ states cause the PA to differ greatly from those of strong, allowed transitions with resonant dipole interactions. The density of spectral lines is lower, the Condon points are at relatively short range, and the reflection approximation for the Franck-Condon factors is not applicable, and the spontaneous decay to bound ground-state molecules is efficient. Finally, the possibility of efficient production of cold molecules is discussed

Generalized Pseudopotentials for Higher Partial Wave Scattering

We derive a generalized zero-range pseudopotential applicable to all partial wave solutions to the Schroedinger equation based on a delta-shell potential in the limit that the shell radius approaches zero. This properly models all higher order multipole moments not accounted for with a monopolar delta function at the origin, as used in the familiar Fermi pseudopotential for s-wave scattering. By making the strength of the potential energy dependent, we derive self-consistent solutions for the entire energy spectrum of the realistic potential. We apply this to study two particles in an isotropic harmonic trap, interacting through a central potential, and derive analytic expressions for the energy eigenstates and eigenvalues.Comment: RevTeX 4 pages, 1 figure, final published versio

Spectroscopy of Ultracold, Trapped Cesium Feshbach Molecules

We explore the rich internal structure of Cs_2 Feshbach molecules. Pure ultracold molecular samples are prepared in a CO_2-laser trap, and a multitude of weakly bound states is populated by elaborate magnetic-field ramping techniques. Our methods use different Feshbach resonances as input ports and various internal level crossings for controlled state transfer. We populate higher partial-wave states of up to eight units of rotational angular momentum (l-wave states). We investigate the molecular structure by measurements of the magnetic moments for various states. Avoided level crossings between different molecular states are characterized through the changes in magnetic moment and by a Landau-Zener tunneling method. Based on microwave spectroscopy, we present a precise measurement of the magnetic-field dependent binding energy of the weakly bound s-wave state that is responsible for the large background scattering length of Cs. This state is of particular interest because of its quantum-halo character.Comment: 15 pages, 12 figures, 4 table