Accurate spectroscopy of Sr atoms

We report the frequency measurement with an accuracy in the 100 kHz range of several optical transitions of atomic Sr : $^1S_0- ^3P_1$ at 689 nm, $^3P_1- ^3S_1$ at 688 nm and $^3P_0- ^3S_1$ at 679 nm. Measurements are performed with a frequency chain based on a femtosecond laser referenced to primary frequency standards. They allowed the indirect determination with a 70 kHz uncertainty of the frequency of the doubly forbidden 5s^2^1S_0- 5s5p^3P_0 transition of $^{87}$Sr at 698 nm and in a second step its direct observation. Frequency measurements are performed for $^{88}$Sr and $^{87}$Sr, allowing the determination of $^3P_0$, $^3P_1$ and $^3S_1$ isotope shifts, as well as the $^3S_1$ hyperfine constants.Comment: 12 pages, 16 figure

Transport of a quantum degenerate heteronuclear Bose-Fermi mixture in a harmonic trap

We report on the transport of mixed quantum degenerate gases of bosonic 87Rb and fermionic 40K in a harmonic potential provided by a modified QUIC trap. The samples are transported over a distance of 6 mm to the geometric center of the anti-Helmholtz coils of the QUIC trap. This transport mechanism was implemented by a small modification of the QUIC trap and is free of losses and heating. It allows all experiments using QUIC traps to use the highly homogeneous magnetic fields that can be created in the center of a QUIC trap and improves the optical access to the atoms, e.g., for experiments with optical lattices. This mechanism may be cascaded to cover even larger distances for applications with quantum degenerate samples.Comment: 7 pages, 8 figure

Observation of the TeV gamma-ray source MGRO J1908+06 with ARGO-YBJ

The extended gamma ray source MGRO J1908+06, discovered by the Milagro air shower detector in 2007, has been observed for about 4 years by the ARGO-YBJ experiment at TeV energies, with a statistical significance of 6.2 standard deviations. The peak of the signal is found at a position consistent with the pulsar PSR J1907+0602. Parametrizing the source shape with a two-dimensional Gauss function we estimate an extension \sigma = 0.49 \pm 0.22 degrees, consistent with a previous measurement by the Cherenkov Array H.E.S.S.. The observed energy spectrum is dN/dE = 6.1 \pm 1.4 \times 10^-13 (E/4 TeV)^{-2.54 \pm 0.36} photons cm^-2 s^-1 TeV^-1, in the energy range 1-20 TeV. The measured gamma ray flux is consistent with the results of the Milagro detector, but is 2-3 times larger than the flux previously derived by H.E.S.S. at energies of a few TeV. The continuity of the Milagro and ARGO-YBJ observations and the stable excess rate observed by ARGO-YBJ along 4 years of data taking support the identification of MGRO J1908+06 as the steady powerful TeV pulsar wind nebula of PSR J1907+0602, with an integrated luminosity above 1 TeV about 1.8 times the Crab Nebula luminosity.Comment: 6 pages, accepted for pubblication by ApJ. Replaced to correct the author lis

Damping of zero sound in Luttinger liquids

We calculate the damping gamma_q of collective density oscillations (zero sound) in a one-dimensional Fermi gas with dimensionless forward scattering interaction F and quadratic energy dispersion k^2 / 2 m at zero temperature. For wave-vectors | q| /k_F small compared with F we find to leading order gamma_q = v_F^{-1} m^{-2} Y (F) | q |^3, where v_F is the Fermi velocity, k_F is the Fermi wave-vector, and Y (F) is proportional to F^3 for small F. We also show that zero-sound damping leads to a finite maximum proportional to |k - k_F |^{-2 + 2 eta} of the charge peak in the single-particle spectral function, where eta is the anomalous dimension. Our prediction agrees with photoemission data for the blue bronze K_{0.3}MoO_3.Comment: final version as published; with more technical details; we have added a discussion of recent work which appeared after our initial cond-mat posting; 13 pages, 5 figure

Electric and magnetic form factors of strange baryons

Predictions for the electromagnetic form factors of the Lambda$, Sigma and Xi hyperons are presented. The numerical calculations are performed within the framework of the fully relativistic constituent-quark model developed by the Bonn group. The computed magnetic moments compare favorably with the experimentally known values. Most magnetic form factors G_M(Q^2) can be parametrized in terms of a dipole with cutoff masses ranging from 0.79 to 1.14 GeV.Comment: 15 pages, 8 figures, 3 tables, submitted to Eur. Phys. J.

Near-threshold production of omega mesons in the pn -> d omega reaction

The first measurement of the p n -> d omega total cross section has been achieved at mean excess energies of Q = 28 and 57 MeV by using a deuterium cluster-jet target. The momentum of the fast deuteron was measured in the ANKE spectrometer at COSY-Juelich and that of the slow "spectator" proton p(sp) from the p d -> p(sp) d omega reaction in a silicon telescope placed close to the target. The cross sections lie above those measured for p p -> p p omega but seem to be below theoretical predictions.Comment: 7 pages, 8 figures; second approach to describe the background has been added; results changed insignificantly, EPJ in pres

Bose-Einstein Condensation and Casimir Effect of Trapped Ideal Bose Gas in between two Slabs

We study the Bose-Einstein condensation for a 3-d system of ideal Bose gas which is harmonically trapped along two perpendicular directions and is confined in between two slabs along the other perpendicular direction. We calculate the Casimir force between the two slabs for this system of trapped Bose gas. At finite temperatures this force for thermalized photons in between two plates has a classical expression which is independent of $\hbar$. At finite temperatures the Casimir force for our system depends on $\hbar$. For the calculation of Casimir force we consider only the Dirichlet boundary condition. We show that below condensation temperature($T_c$) the Casimir force for this non-interacting system decreases with temperature($T$) and at $T\gtrsim T_c$, it is independent of temperature. We also discuss the Casimir effect on 3-d highly anisotropic harmonically trapped ideal Bose gas.Comment: 4 page

Extended morphometric analysis of neuronal cells with Minkowski valuations

Minkowski valuations provide a systematic framework for quantifying different aspects of morphology. In this paper we apply vector- and tensor-valued Minkowski valuations to neuronal cells from the cat's retina in order to describe their morphological structure in a comprehensive way. We introduce the framework of Minkowski valuations, discuss their implementation for neuronal cells and show how they can discriminate between cells of different types.Comment: 14 pages, 18 postscript figure

Identification of the TeV Gamma-ray Source ARGO J2031+4157 with the Cygnus Cocoon

The extended TeV gamma-ray source ARGO J2031+4157 (or MGRO J2031+41) is positionally consistent with the Cygnus Cocoon discovered by $Fermi$-LAT at GeV energies in the Cygnus superbubble. Reanalyzing the ARGO-YBJ data collected from November 2007 to January 2013, the angular extension and energy spectrum of ARGO J2031+4157 are evaluated. After subtracting the contribution of the overlapping TeV sources, the ARGO-YBJ excess map is fitted with a two-dimensional Gaussian function in a square region of $10^{\circ}\times 10^{\circ}$, finding a source extension $\sigma_{ext}$= 1$^{\circ}$.8$\pm$0$^{\circ}$.5. The observed differential energy spectrum is $dN/dE =(2.5\pm0.4) \times 10^{-11}(E/1 TeV)^{-2.6\pm0.3}$ photons cm$^{-2}$ s$^{-1}$ TeV$^{-1}$, in the energy range 0.2-10 TeV. The angular extension is consistent with that of the Cygnus Cocoon as measured by $Fermi$-LAT, and the spectrum also shows a good connection with the one measured in the 1-100 GeV energy range. These features suggest to identify ARGO J2031+4157 as the counterpart of the Cygnus Cocoon at TeV energies. The Cygnus Cocoon, located in the star-forming region of Cygnus X, is interpreted as a cocoon of freshly accelerated cosmic rays related to the Cygnus superbubble. The spectral similarity with Supernova Remnants indicates that the particle acceleration inside a superbubble is similar to that in a SNR. The spectral measurements from 1 GeV to 10 TeV allows for the first time to determine the possible spectrum slope of the underlying particle distribution. A hadronic model is adopted to explain the spectral energy distribution.Comment: 16 pages, 3 figures, has been accepted by ApJ for publicatio

PEMBELAJARAN MEMPRODUKSI TEKS EKSPLANASI KOMPLEKS DENGAN MENGGUNAKAN MEDIA CARD PROBLEM PADA PESERTA DIDIK KELAS XI SMA KARTIKA XIX - 1 BANDUNG TAHUN PELAJARAN 2015/2016

Teks Eksplanasi merupakan teks yang menjelaskan proses. Proses tersebut dapat terjadi secara alamiah, baik yang berkaitan dengan fenomena (gejala) alam maupun fenomena sosial budaya. Penemuan ( Card Problem ) yait u pengujian kemampuan siswa dengan memberikan perm asalahan . Sehubungan dengan hal tersebut, penulis tertarik untuk melakukan penelitian mengenai pembelajaran Memproduksi Teks Eksplanasi Kompleks dengan Menggunakan Media Card Problem pada Peserta Didik Kelas XI SMA Kartika XIX - 1 Bandung Tahu n Pelajaran 2015/2016 . Rumusan masalah yang penulis ajukan adalah; (1) Mampu - kah penulis merencanakan, menerapkan, dan menilai kegiatan pembelajaran mem - produksi teks eksplanasi kompleks dengan menggunakan media card problem pada peserta didik kelas XI SMA Kartika XIX - 1 Bandung? (2) Mampukah peserta didik kelas XI SMA Kartika XIX - 1 Bandung mengikuti kegiatan pembelajaran memproduksi teks eksplanasi kompleks dengan struktur, kaidah kebahasaan, dan penulisan kalimat? (3) Mampukah peserta didik kelas XI SMA Ka rtika XIX - 1 Bandung mengikuti kegiatan pembelajaran memproduksi teks eksplanasi kompleks dengan struktur, kaidah kebahasaan, dan penulisan kalimat? Tujuan dari penelitian ini, untuk mengetahiu kemampuan penulis, siswa, dan keefektifan media pembelajaran. Hipotesis yang penulis rumusk an yang penulis rumuskan yaitu: (a) Penulis mampu melaksanakan pembelajaran mem - produksi teks eksplanasi kompleks dengan menggunakan media Card Problem pada peserta didik kelas XI SMA Kartika XIX - 1 Bandung . (b) Peserta didik ke las XI SMA Kartika XIX - 1 Bandung mampu mengikuti pem - belajaran memproduksi teks eksplanasi kompleks dengan menggunakan media Card Problem . (c) Media Card Problem efektif digunakan dalam pembelajaran memproduksi teks ekspla - nasi kompleks dengan menggunakan media Card Problem pada peserta didik kelas XI SMA Kartika XIX - 1 Bandung . Metode penelitian yang penulis gunakan adalah metode eksperimen de - ngan teknik penelitian telaah pustaka, observasi, tes, dan teknis analisis. Adapun hasil penelitian sebagai berikut. (1) P enulis mampu merencanakan dan melaksanakan pembelajaran Memproduksi Teks Eksplanasi Kompleks dengan Menggunakan Media Card Problem pada Peserta Didik Kelas XI SMA Kartika XIX - 1 Bandung . Hal ini ter bukti dari hasil nilai perencanaan 3,78 dan pelaksanaan sebesar 3,72. (2) Siswa kelas XI SMA Kartika XIX - 1 Bandung mampu Memproduksi Teks Eksplanasi Kompleks dengan Menggunakan Media Card Problem pada Peserta Didik Kelas XI SMA Kartika XIX - 1 Bandung . Hal ini terbukti dari nilai rata - rata pretes yait u 70,32 dan nilai rata - rata postes yaitu 92,16 . Jadi, ada peningkatan sebesar 21,84 atau setara dengan 81 . 46 %. (3) Media Card Problem tepat digunakan dalam pembelajaran Memproduksi Teks Eksplanasi Kompleks pada Peserta Didik Kelas Xi SMA KartiakXIX - 1 Bandu ng . Hal ini terbukti dari hasil perhitungan statistik dengan hasil t hitung 9,21 > 2,06 yakni pada tingkat ke percayaan 95%, dan d.b sebesar 2 4 . Kata Kunci : Pembelajaran, Memproduksi, Teks, Eksplanasi Kompleks, dengan, Menggunakan, Media, Card Problem