Elliptic flow of charged particles in Pb-Pb collisions at 2.76 TeV

We report the first measurement of charged particle elliptic flow in Pb-Pb collisions at 2.76 TeV with the ALICE detector at the CERN Large Hadron Collider. The measurement is performed in the central pseudorapidity region (|$\eta$|<0.8) and transverse momentum range 0.2< $p_{\rm T}$< 5.0 GeV/$c$. The elliptic flow signal v$_2$, measured using the 4-particle correlation method, averaged over transverse momentum and pseudorapidity is 0.087 $\pm$ 0.002 (stat) $\pm$ 0.004 (syst) in the 40-50% centrality class. The differential elliptic flow v$_2(p_{\rm T})$ reaches a maximum of 0.2 near $p_{\rm T}$ = 3 GeV/$c$. Compared to RHIC Au-Au collisions at 200 GeV, the elliptic flow increases by about 30%. Some hydrodynamic model predictions which include viscous corrections are in agreement with the observed increase.Comment: 10 pages, 4 captioned figures, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/389

Higher harmonic anisotropic flow measurements of charged particles in Pb-Pb collisions at 2.76 TeV

We report on the first measurement of the triangular $v_3$, quadrangular $v_4$, and pentagonal $v_5$ charged particle flow in Pb-Pb collisions at 2.76 TeV measured with the ALICE detector at the CERN Large Hadron Collider. We show that the triangular flow can be described in terms of the initial spatial anisotropy and its fluctuations, which provides strong constraints on its origin. In the most central events, where the elliptic flow $v_2$ and $v_3$ have similar magnitude, a double peaked structure in the two-particle azimuthal correlations is observed, which is often interpreted as a Mach cone response to fast partons. We show that this structure can be naturally explained from the measured anisotropic flow Fourier coefficients.Comment: 10 pages, 4 figures, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/387

Pakeliran Wayang Kulit Purwa Lakon Salya Begal Di Pondok Seni Dan Budaya Boediardjo Borobudur

Penelitian ini bertujuan untuk mendapatkan gambaran yang jelas dan rinci mengenai pakeliran wayang kulit purwa lakon Salya Begal di Pondok Seni dan Budaya Boediardjo Borobudur, yang rnenyangkut tentang makna bagi kornunitas Pondok seni dan budaya Boediardjo di Borobudur Kabupaten Magelang. Unguk memberikan eksplanasi terhadap permasalahan yang dibahas, digunakan metode deskriptif analisis serta dengan pendekatan i1rnu- ilmu sosial yang ada hubungannya dengan penelitian ini. Munculnya pakeliran wayang kulit purwa lakon Salya Begal di Pondok Seni dan Budaya Boediardjo ada hubungannya dengan figur almarhurn Boediardjo, karena pakeliran tersebut disajikan setiap setahun sekali pada bulan Nopember oleh Yayasan Pondok Seni dan Budaya Boediardjo untuk memperingati kelahiran Boediardjo, yang lahir pada tanggal 16 Nopember 1921. Lakon Salya Begal ini muncul pertama kali pada saat upacara peringatan ulang tahun kelahiran Boediardjo yang ke 75 di Jakarta oleh prakarsa pribadi Boediardjo, dengan disertai parneran foto dan peluncuran bukunya berjudul “Siapa Sudi Saya Dongengi” yang berisi tentang riwayat kehidupannya. Pada bagian akhir tulisannya dicantumkan sinopsis Salya Begal sebagai epilog. Selanjutnya sinopsis ini dijadikan pijakan penyajian pakeliran lakon Salya Begal di Pondok Seni dan Budaya Boediardjo. Sehubungan dengan hal tersebut, maka pakeliran Salya Begal bukan semata-mata sajian seni hiburan, tetapi sajian seni yang mempunyai makna simbolis. Lakon Salya Begal sebagai simbol perasaan orang yang sedang kecewa dan putus asa, sedangkan bagi komunitas Pondok Seni dan Budaya Boediarcljo, lakon Salya Begal sebagai simbol sarana pengungkapan rasa hormat dan kagum terhadap sosok Boediardjo

Numerical investigation of spin-torque using the Heisenberg model

We present numerical calculations of the spin transfer torque resulting in current-induced domain wall motion. Rather than the conventional micromagnetic finite difference or finite element method, we use an atomistic/classical Heisenberg spin model approach, which is well suited to study geometrically confined domain walls. We compute the behaviour of domain walls in a one dimensional chain when currents are injected using adiabatic and non-adiabatic spin torque terms. Our results are compared to analytical calculations and are found to agree very well for small current densities. At larger current densities deviations are observed, which can be attributed to the approximations used in the analytical calculations. Copyright EDP Sciences/Società Italiana di Fisica/Springer-Verlag 200772.25.Ba Spin polarized transport in metals, 72.25.Pn Current-driven spin pumping,