Strange Particle Production and Elliptic Flow from CERES

Elliptic flow measurements as a function of p_T of charged (pi^+- and low-p_T protons) and strange (Lambda and K^0_S) particles from Pb+Au collisions at 158 AGeV/c are presented, together with measurements of phi and K^0_S meson production. A mass ordering effect was observed. Scaling to the number of constituent quarks and transverse rapidity y^fs_T scaling are presented. The results are compared with results from the NA49 and STAR experiments and with hydrodynamical calculations. For the first time in heavy-ion collisions, phi mesons were reconstructed in the same experiment both in the K^+K^- and in the e^+e^- decay channels. The obtained transverse mass distributions of phi mesons are compared with results from the NA49 and NA50 experiments. The yield and the inverse slope parameter of the K^0_S mesons were reconstructed from two independent analyses. Our results are compared with those from the NA49 and NA57 experiments.Comment: Submitted to J. Phys. G (Proceedings of the 9th International Conference on Strangeness in Quark Matter, Los Angeles, USA, March 26-31) 9 pages, 7 figure

Investigation of Azimuthal Asymmetries in Charged and Strange Particle Distributions from CERES

Diese Doktorarbeit stellt die Messung des anisotropen transversalen Flusses v2 geladener und seltsamer Teilchen mit dem CERES Spektrometer vor. Gezeigt werden die elliptischen Fluss Messungen der Teilchen Lambda, K^0_S, geladener Pions und protons in Pb-Au Kollisionen bei hoechsten SPS Energien. Mit einem Pseudorapiditaetsbereich von \eta=2.05-2.70 bei voller azimuthaler Akzeptanz und mit einer pT Sensitivitaet von bis zu 4 GeV/c koennen mit den CERES Daten hydrodynamische Modelle getestet werden. v2 wird als Funktionen der Zentralitaet, Rapiditaet, Pseudorapiditaet und des Transversalimpulses fuer die verschiedenen Teilchensorten diskutiert. Die Messungen werden mit Ergebnissen der NA49 Experimentes und mit hydrodynamischen Rechnungen verglichen.Ferner werden Vergleiche zu den STAR und RHICH Beobachtungen angestellt. Bei kleinem pT wird der Massenordnungseffekt v2(Lambda)<v2(K^0_S)<Pions) beobachtet. Ein entgegengesetztes Verhalten zeigt sich bei hohem pT. Um ein teiferes Verstaendniss fuer die Ursachen des Skalenverhaltens des kollektiven Flusses mit der Anzahl an Konstituentenquarks und mit der transversalen Rapiditaet zu erhalten, wird die von der Hydrodynamiek vorhergesagte y^fs_T Skalierung durchgefuehrt. Vergleiche differentieller Flussmessungen verschiedenster Teilchen mit verschiedenen Szenarien an Skalenverhalten ermoeglicht eine Aussage ueber die Ursachen des Flusses, sowie ueber die fruehesten Stadien der Kollision

Crime and Punishment in Distributed Byzantine Decision Tasks (Extended Version)

A decision task is a distributed input-output problem in which each process starts with its input value and eventually produces its output value. Examples of such decision tasks are broad and range from consensus to reliable broadcast to lattice agreement. A distributed protocol solves a decision task if it enables processes to produce admissible output values despite arbitrary (Byzantine) failures. Unfortunately, it has been known for decades that many decision tasks cannot be solved if the system is overly corrupted, i.e., safety of distributed protocols solving such tasks can be violated in unlucky scenarios. By contrast, only recently did the community discover that some of these distributed protocols can be made accountable by ensuring that correct processes irrevocably detect some faulty processes responsible for any safety violation. This realization is particularly surprising (and positive) given that accountability is a powerful tool to mitigate safety violations in distributed protocols. Indeed, exposing crimes and introducing punishments naturally incentivize exemplarity. In this paper, we propose a generic transformation of any non-synchronous distributed protocol solving a decision task into its accountable version. Our transformation is built upon the well-studied simulation of crash failures on top of Byzantine failures and increases the communication complexity by a quadratic multiplicative factor in the worst case

UPAYA MENINGKATKAN MOTIVASI BELAJAR SISWA MELALUI MEDIA GAME EDUCATION DALAM PEMBELAJARAN IPS DI MTs HASBUR RACHMAN ALIF DESA LENGKONG WETAN KABUPATEN MAJALENGKA

ASEP SAMSUL MA'ARIF : Berdasarkan Observasiawal di kelas VII MTs Hasbur Rachman Alif terlihat proses pembelajaran IPS masih menggunakan media spidol dan papan tulis. Sehingga banyak siswa yang kurang memperhatikan guru pada saat proses pembelajaran., Hal ini berakibat pada kejenuhan dan kebosanan yang berdampak pada hasil belajar siswa yang kurang dari KKM yang diterapkan di MTs Hasbur Rachman Alif yakni 70. Tujuan penelitian ini untuk mengetahui bagaimana penerapan pembelajaran dengan menggunakan media Game Education pada mata pelajaran IPS Terpadu, aktivitas siswa dan kinerja guru dengan pembelajaran dengan menggunakan media Game Education, dan mengetahui motivasi belajar siswa sebelum dan setelah diterapkannya pembelajaran dengan menggunakan media Game education pada mata pelajaran IPS Terpadu di MTs Hasbur Rachman Alif. Pembelajaran dengan menggunakan media Game Education menekankan motivasi siswa untuk berpikir kritis dan menuangkan. Hal ini memudahkan siswa untuk mengakses materi IPS yang banyak dimanapun, serta mempemudah daya ingat siswa tentang apayatgtelah didapatkan selama proses pembelajaran. Penelitian ini menggunakan Penelitian Tindakan Kelas (pTK) yang dilaksanakan selama tiga siklus. Teknik Pengumpulan data menggunakan observasi, tes, dan dokumentasi. Subjek penelitian ini adalah siswa kelas VII MTs Hasbur Rachman Alif sebanyak 31 siswa yang terdiri dari 18 siswa laki-laki dan 13 siswa perempuan. Pembelajaran dengan menggunakan media Game Education dapat meningkatkan motivasi belajar siswa hal ini terlihat dari hasil tes yang telah dilakukan selama tiga siklus, dimana pada pratindakan (pretes) nilai sebesar 65,25 dan ketuntasan belajar 25 yo, siklus I nilai rata-rata sebesar 76,75 dan ketuntasan_ belajar siswa sebesar 65,5%o siklus II nilai rata-rata siswa 85,75 dan nilai ketuntasan belajar sebesar 90% siklus III dengan nilai rata-rata 92,25 dan ketuntasan belajar mengalami peningkatanya itu 97,5yo. Dengan demikian dapat disimpulkan bahwa pembelajaran dengan menggunakan media Game Education merupakan salah satu upaya untuk meningkatkan hasil belajar siswa pada mata pelajaran IPS Terpadu di MTs Hasbur Rachman Alif. Kata Kunci: Game Education, MotivasiBelajar, PTK

Measurement of quarkonium production at forward rapidity in pp collisions at √s=7 TeV

The inclusive production cross sections at forward rapidity of J/ψ , ψ(2S) , Υ (1S) and Υ (2S) are measured in pp collisions at s√=7 TeV with the ALICE detector at the LHC. The analysis is based on a data sample corresponding to an integrated luminosity of 1.35 pb‾¹ . Quarkonia are reconstructed in the dimuon-decay channel and the signal yields are evaluated by fitting the μ+μ− invariant mass distributions. The differential production cross sections are measured as a function of the transverse momentum pT and rapidity y , over the ranges 0<pT<20 GeV/c for J/ψ , 0<pT<12 GeV/c for all other resonances and for \(2.5 . The measured cross sections integrated over pT and y , and assuming unpolarized quarkonia, are: σJ/ψ=6.69±0.04±0.63 μ b, σψ(2S)=1.13±0.07±0.19 μ b, σΥ(1S)=54.2±5.0±6.7 nb and σΥ(2S)=18.4±3.7±2.9 nb, where the first uncertainty is statistical and the second one is systematic. The results are compared to measurements performed by other LHC experiments and to theoretical models

Production of charged pions, kaons and protons at large transverse momenta in pp and Pb-Pb collisions at sNN\sqrt{s_{NN}} = 2.76 TeV

Transverse momentum spectra of $\pi^{\pm}, K^{\pm}$ and $p(\bar{p})$ up to $p_T$ = 20 GeV/c at mid-rapidity, |y| $\le$ 0.8, in pp and Pb-Pb collisions at $\sqrt{s_{NN}}$ = 2.76 TeV have been measured using the ALICE detector at the LHC. At intermediate $p_T$ (2-8 GeV/c) an enhancement of the proton-to-proton ratio, (p + \bar{p})/(\pi^+ + \pi^-\(), with respect to pp collisions is observed and the ratio reaches 0.80 in central Pb-Pb collisions. The measurement of the nuclear modification factors for \(\pi^{\pm}, K^{\pm} and $p(\bar{p})$ indicates that within the systematic and statistical uncertainties they are the same at high $p_T$ (> 10 GeV/c), suggesting that the chemical composition of leading particles from jets in the medium is similar to that of vacuum jets.publishedVersio

Charmonium and e+e−e^+e^- pair photoproduction at mid-rapidity in ultra-peripheral Pb-Pb collisions at sNN\sqrt{s_{NN}} = 2.76 TeV

The ALICE Collaboration at the LHC has measured the $J/\psi$ and $\psi$' photoproduction at mid-rapidity in ultra-peripheral Pb-Pb collisions at $\sqrt{s_{NN}}$ = 2.76 TeV. The charmonium is identified via its leptonic decay for events where the hadronic activity is required to be minimal. The analysis is based on an event sample corresponding to an integrated luminosity of about 23 ${\mu}b^{-1}$, The cross section for coherent and incoherent $J/\psi$ production in the rapidity interval -0.9 < y < 0.9, are $d\sigma_{J/\psi}^{coh}/dy = 2.38^{+0.34}_{-0.24}(sta+sys)$ mb and $d\sigma_{J/\psi}^{inc}/dy = 0.98^{+0.19}_{-0.17}(sta+sys)$ mb, respectively. The results are compared to theoretical models for $J/\psi$ production and the coherent cross section is found to be in good agreement with those models which include nuclear gluon shadowing consistent with EPS09 parametrization. In addition the cross section for the process $\gamma\gamma \to e^+e^-$ has been measured and found to be in agreement with the STARLIGHT Monte Carlo predictions.publishedVersio

Measurement of charm and beauty production at central rapidity versus charged-particle multiplicity in proton-proton collisions at s\sqrt{s} = 7 TeV

Prompt D meson and non-prompt J/$\psi$ yields are studied as a function of the multiplicity of charged particles produced in inelastic proton-proton collisions at a centre-of-mass energy of $\sqrt{s}=7$ TeV. The results are reported as a ratio between yields in a given multiplicity interval normalised to the multiplicity-integrated ones (relative yields). They are shown as a function of the multiplicity of charged particles normalised to the average value for inelastic collisions (relative charged-particle multiplicity). D\)^0\), D\)^+\) and D\)^{*+}\) mesons are measured in five $p_{\rm T}$ intervals from 1 to 20 GeV/$c$ and for $|y|1.3$ GeV/$c$ and $|y|0$, The fraction of non-prompt J/$\psi$ in the inclusive J/$\psi$ yields shows no dependence on the charged-particle multiplicity at central rapidity. Charm and beauty hadron relative yields exhibit a similar increase with increasing charged-particle multiplicity. The measurements are compared to PYTHIA 8, EPOS 3 and percolation calculations.publishedVersio

Measurement of the Cross Section for Electromagnetic Dissociation with Neutron Emission in Pb-Pb Collisions at √sNN = 2.76 TeV

The first measurement of neutron emission in electromagnetic dissociation of 208Pb nuclei at the LHC is presented. The measurement is performed using the neutron Zero Degree Calorimeters of the ALICE experiment, which detect neutral particles close to beam rapidity. The measured cross sections of single and mutual electromagnetic dissociation of Pb nuclei at √sNN = 2.76 TeV with neutron emission are σ_single EMD = 187.2±0.2 (stat.) +13.8−12.0 (syst.) b and σ_mutual EMD = 6.2 ± 0.1 (stat.) ±0.4 (syst.) b respectively. The experimental results are compared to the predictions from a relativistic electromagnetic dissociation model.publishedVersio