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

Pseudorapidity dependence of the anisotropic flow of charged particles in Pb–Pb collisions at sNN=2.76 TeV

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Not AvailableDepending on the position on the panicle, grain filling differs for spikelets on primary branches and secondary branches of upper and lower portions in rice (Oryza sativa L.). With the objective of identifying candidate genes associated with the grain-filling process across the panicle, a candidate gene (CG)-based mapping approach was attempted in an F 2 population derived from the cross between Rasi, a rice variety known for its good grain filling, and IC114927, a local landrace. The grain filling (%) was characterized for 444 F 2 individual plants across the panicle. Within the F 2 population, thirteen plants were identified with >90% grain filling across the panicle. For 120 markers designed from 1 kb upstream and within the candidate genes reported to be involved in translocation process of sugars, 18.3% polymorphism was observed. Using a selective genotyping approach comprising 24 individuals from eight groups based on their filling and position, two associated CG markers were identified. Further analysis of the mapping population showed a CG marker based on the sucrose phosphate synthase gene on chromosome 2 to be significantly associated with filling of grains on primary branches of the upper half of the panicle and another CG marker based on the transporter gene on chromosome 11 to be associated with filling of grains on primary branches of the lower half; secondary branches of the upper half and lower half of the panicle. Both the positive alleles were contributed by the variety Rasi. With a candidate gene-based marker mapping approach, two genes involved in sugar translocation and transport were identified to be directly associated with grain filling in rice

Description and performance of track and primary-vertex reconstruction with the CMS tracker

A description is provided of the software algorithms developed for the CMS tracker both for reconstructing charged-particle trajectories in proton-proton interactions and for using the resulting tracks to estimate the positions of the LHC luminous region and individual primary-interaction vertices. Despite the very hostile environment at the LHC, the performance obtained with these algorithms is found to be excellent. For t (t) over bar events under typical 2011 pileup conditions, the average track-reconstruction efficiency for promptly-produced charged particles with transverse momenta of p(T) > 0.9GeV is 94% for pseudorapidities of vertical bar eta vertical bar < 0.9 and 85% for 0.9 < vertical bar eta vertical bar < 2.5. The inefficiency is caused mainly by hadrons that undergo nuclear interactions in the tracker material. For isolated muons, the corresponding efficiencies are essentially 100%. For isolated muons of p(T) = 100GeV emitted at vertical bar eta vertical bar < 1.4, the resolutions are approximately 2.8% in p(T), and respectively, 10 m m and 30 mu m in the transverse and longitudinal impact parameters. The position resolution achieved for reconstructed primary vertices that correspond to interesting pp collisions is 10-12 mu m in each of the three spatial dimensions. The tracking and vertexing software is fast and flexible, and easily adaptable to other functions, such as fast tracking for the trigger, or dedicated tracking for electrons that takes into account bremsstrahlung

Search for excited quarks in the gamma plus jet final state in proton-proton collisions at root s=8 TeV

A search for excited quarks decaying into the gamma + jet final state is presented. The analysis is based on data corresponding to an integrated luminosity of 19.7 fb(-1) collected by the CMS experiment in proton-proton collisions at root s = 8 TeV at the LHC. Events with photons and jets with high transverse momenta are selected and the gamma + jet invariant mass distribution is studied to search for a resonance peak. The 95% confidence level upper limits on the product of cross section and branching fraction are evaluated as a function of the excited quark mass. Limits on excited quarks are presented as a function of their mass and coupling strength; masses below 3.5 TeV are excluded at 95% confidence level for unit couplings to their standard model partners