η\eta meson reconstruction in pp reactions at 2.2 GeV with HADES

The HADES spectrometer installed at GSI Darmstadt is devoted to study the production of di-electron pairs from proton, pion and nucleus induced reactions at 1-2 AGeV. In pp collisions at 2.2 GeV we have focused mainly on exclusive reconstruction of the $\eta$ meson decays in the hadronic ($\eta\to\pi^{+}\pi^{-}\pi^{0}$) and the electromagnetic channels ($\eta\to e^{+}e^{-}\gamma$). We present analysis techniques and discuss first results on $\eta$ production, with the main focus on comparisons of reconstructed distributions to results obtained by other experiments and theoretical predictions.Comment: Presented on Meson2006 conference, 4 pages, 4 figure

Dielectron Production in C+C Collisions at 1 GeV/u and the Solution to the DLS Puzzle

The production of e+e- pairs in C+C collisions at 1 GeV/u was investigated with the HADES experiment at GSI, Darmstadt. In the invariant-mass region $0.15\: GeV/c^{2} \leq M_{ee} \leq 0.5\: GeV/c^{2}$ the measured pair yield shows a strong excess above the contribution expected from hadron decays after freeze-out. The data are in good agreement with the results of the former DLS experiment for the same system and energy.Comment: 6 pages, 3 figures, conference proceedings: Quark Matter 2008, Jaipur (India), 4-10 February 2008, submitted to J. Phys. G: Nuclear and Particle Physic

Probing resonance matter with virtual photons

In the energy domain of 1-2 GeV per nucleon, HADES has measured rare penetrating probes (e+e-) in C+C, Ar+KCl, d+p, p+p and p+Nb collisions. For the first time the electron pairs were reconstructed from quasi-free n+p sub-reactions by detecting the proton spectator from the deuteron breakup. An experimentally constrained NN reference spectrum was established. Our results demonstrate that the gross features of di-electron spectra in C+C collisions can be explained as a superposition of independent NN collisions. On the other hand, a direct comparison of the NN reference spectrum with the e+e- invariant mass distribution measured in the heavier system Ar+KCl at 1.76 GeV/u shows an excess yield above the reference, which we attribute to radiation from resonance matter. Moreover, the combined measurement of di-electrons and strangeness in Ar+KCl collisions has provided further intriguing results which are also discussed.Comment: 10 pages, 3 figures, proceedings of the International Nuclear Physics Conference - INPC 2010, Vancouver, Canada, July 4 - 9 201

PENGARUH KETERAMPILAN MENGAJAR GURU TERHADAP MOTIVASI BELAJAR SISWA KELAS V MATA PELAJARAN MATEMATIKA

Penelitian ini bertujuan untuk mengetahui pengaruh keterampilan mengajar guru terhadap motivasi belajar siswa. Penelitian ini dilaksanakan di SDN 030316 Sukandebi kecamatan tigalingga. Sampel dalam penelitian yang terdiri dari 2 kelas yaitu kelas VA dan VB. Kelas VA dengan jumlah 50 siswa dan kelas VB dengan jumlah 25 siswa. Jenis penelitian ini adalah kuantitatif. Alat pengumpulan data yang digunakan untuk mengetahui keterampilan mengajar guru dan Motivasi belajar siswa adalah angket yang telah di uji validasi dan realibilitasnya. Kedua berdistribusi normal kerena 0,200 ≥ 0,05. Dari uji linearitas diketahui nilai signifikan deviation from lineariti sebesar 0, 806 ≥ 0,05. Maka dapat disimpulkan bahwa terdapat hubungan yang linear antara keterampilan mengajar guru dengan motivasi belajar siswa. Dilakukan uji t pada taraf nyata (∝ =0,05) bahwa  ≥  yaitu 5,864 ≥ 2,010 dengan ini membuktikan bahwa  diterima, sehingga penulis menyimpulkan bahwa ada pengaruh yang signifikan dari keterampilan mengajar guru terhadap motivasi belajar siswa kelas V pada mata pelajaran matematika di SDN 030316 Sukandebi