Particle identification for Higgs physics in the ATLAS experiment

ATLAS is a general purpose experiment which will operate at the LHC. In the main focus of ATLAS is the investigation of the nature of the electroweak symmetry breaking, and therefore the search for the Higgs boson. Electrons, photons, muons, tau and b-jets are important components of the possible physics signatures expected. Thus the particle-ID impose strong requirements upon the performance of the detector, it has to be sensitive to Higgs boson over the full range of allowed masses. In this paper, the detector performance in terms of particle identification is presented

Application of TauSpinner for studies on tau-lepton polarization and spin correlations in Z, W and H decays at LHC

The tau-lepton plays an important role in the physics program at LHC. Its spin can be used for separation of signal from background or in measuring properties of New Particles decaying to tau leptons. The TauSpinner package represents a tool to modify tau spin effects in any sample containing tau leptons. Generated events, featuring taus produced from intermediate state W, Z, H bosons can be used as an input. The information on the polarization and spin correlations is reconstructed from the kinematics of the tau lepton(s) (nutau in case of W-mediated processes) and tau decay products. By weights, attributed on the event-by-event basis, it enables numerical evaluation and/or modification of the spin effects. We review distributions to monitor spin effects in leptonic and hadronic tau decays with up to three pions, to provide benchmarks for validation of spin content of the event sample and to visualize the tau lepton spin polarization and correlation effects. The demonstration examples for use of TauSpinner libraries, are documented. New validation methods of such an approach are provided. Other topics, like TauSpinner systematic errors or sensitivity of experimental distributions to spin, are addressed in part only. This approach is of interest for implementation of spin effects in embedded tau lepton samples, where Z to mu mu events from data of muons are replaced by simulated tau leptons. Embedding is used at LHC for estimating Z to tau tau background to H to tau tau signatures.Comment: 1+41 pages, 5 figures in main text, multitude of figures in appendice

Turbulent Mixing in Bottom Boundary Layer of the Coastal Ocean

This paper analyses the evolution of the bottom boundary layer observed over a flood tide in the Plymouth Sound in June 2006. The overview of the energy budget associated with turbulence is presented in which an estimation of turbulent energy dissipation and production in the boundary layer is performed. Turbulent characteristics are calculated from data collected by two Acoustic Doppler Velocimeters (ADV) located at 69 cm and 52 cm above the sea bed. The same turbulent characteristics are calculated, but applying different methods, using the velocity measured by a downlooking 1200 kHz Acoustics Doppler Current Profiler (ADCP) installed at a height 1.36m above the bed. The study compares turbulent characteristics calculated from data collected by two different types of instruments. Additionally, the currents in the whole water column are examined by analysing profiles of velocity collected by 600 kHz ADCP. The study checks whether the velocities measured by the two ADCPs are consistent with each other and examines the possible effects of density stratification on turbulence in the bottom boundary layer. It was found that the flow was an effect of semidiurnal tide with the maximum velocities of 22cm/s observed two hours after Low Water 4m above the bed. Velocity profiles, measured by the two ADCP, did not overlap each other but the results are consistent with each other. Measurements performed by both ADVs showed the same magnitudes and trends in the mean velocity as the 1.2MHz ADCP. The results indicated weak stratification in the water column. Velocities measured by 1.2MHz ADCP had logarithmic profiles from which the friction velocity (u*) and bed stress (τb) were calculated. The characteristics had similar values (u*<1cm/s, τb<0.09Pa) as reported previously for similar conditions (flat bed, tidal channel, unstratified water column). Dissipation rate (ε) calculated from the two ADVs provided inaccurate results which were three orders of a magnitude higher than that obtained from the higher frequency ADCP (10-8-10-6 W/kg). That difference was found to be associated with the assumptions of the first method, which were not fulfilled. The production of TKE (P), from ADVs and the 1.2MHz ADCP, had the same magnitude than ε and the average ε/P ratio, over the whole time of deployment, was found to be 1.45 +/- 1.07. However, the ratio was biased by the high ε during run 2. After rejecting that run the ratio was closer to the expected value of unity: 0.78 +/- 0.36

Tau leptons as a probe for new physics at LHC

The tau leptons identification with ATLAS experiment will be possible already at the early start of the data taking. The copius production of W and Z bosons decaying to the tau leptons will provide unique possibility to calibrate and undertand identification of hadronically decaying tau's above the QCD background already with few hundreds of pb-1. With integrated luminosity of tens of fb-1, tau leptons will become an excellent probe for searching for the SM and MSSM Higgs boson, SUSY or extra dimensions. In the talk we review prospect for early physics and searches scenarios involving tau leptons

Kinetics of gas emission from aluminosilicates used as a relaxing additive for moulding and core sands

The article presents the results of gas emissions generated during heating of mineral additives – aluminosilicates (perlite ore and vermiculite). The test on a laboratory stand for a 1 g sample at 1 000 °C was carried out. It has been shown, that there is a correlation between the degree of fragmentation and the amount of gas generated. The finest fraction of perlite ore caused a similar quantitative gas emission as ground vermiculite. The presence of additives in molding sands, regardless of the size of fraction, should not affect the formation of casting defects. The addition of perlite ore and vermiculite does not effect the ecological properties of moulding sand

Modified polysaccharides as alternative binders for foundry industry

Polysaccharides constitute a wide group of important polymers with many commercial applications, for example food packaging, fibres, coatings, adhesives etc. This review is devoted to the presentation of polysaccharide application in foundry industry. In this paper the selected properties of foundry moulding sand and core sand containing modified polysaccharides as binders are presented according to foreign literature data. Also, author’s own research about effect of using moulding sand binder consisting of modified polysaccharide (modified starch) or its composition with non-toxic synthetic polymers are discussed. Based on technologies taken under consideration in this paper, it could be concluded that polysaccharides are suitable as an alternative for use as binder in foundry moulding applications

Metamagnetism in the XXZ model with next-to-nearest-neighbor coupling

We investigate groundstate energies and magnetization curves in the one dimensional XXZ-model with next to nearest neighbour coupling $\alpha>0$ and anisotropy $\Delta$ ($-1 \le \Delta \le 1$) at T=0. In between the familiar ferro- and antiferromagnetic phase we find a transition region -- called metamagnetic phase -- where the magnetization curve is discontinuous at a critical field $B_c(\alpha,\Delta)$.Comment: LaTeX file (text) + 5 PS files (5 figures

The influence of pollen viability on seed set and fruit mass in strawberry (fragaria x ananassa duch.)

This research was conducted in 2006 in the Experimental Station of the Department of Genetics and Horticultural Plant Breeding in Felin near Lublin. It included 7 cultivars of strawberry ('Pastel', 'Salut', 'Teresa', 'Jota', 'Paula', 'Senga Sengana', 'Plena') and two selected clones: 2395 and 3995 that belonged to the Department. Analysis of pollen fertility was carried out on the basis of materials collected on five occasions: on May 17 (at the beginning of florescence), May 20 and May 24 (the peak of florescence) and on June 2 and June 13 (the end of florescence). Smear preparations stained with 2% acetocarmin and glycerin solution (1:1) were used to test pollen viability. The highest percent of viable pollen in 2006 was in cultivar 'Jota' (70.88%). The lowest viability had pollen of 'Teresa' cultivar (33.83%). The average content of viable pollen grains was the lowest on May 20 (36.79%). The highest pollen fertility was noted on June 2 (62.15%), the percent of fertile pollen on a similar level was observed on May 17 and 24 and June13. The cultivar 'Jota' was characterized by an increased level of pollen fertility that was quite high during the whole period of florescence. The number of seeds has a great influence on the proper development of spurious strawberry fruit. The mass of seeds from a single fruit has a great influence on the mass of fruits in both large and small fruit categories. Pollen viability affected the mass of seeds on big fruits (r = 0.444), but there is no clear direct relationship between pollen fertility and mass of strawberry fruit(r = -0.193 and r = -0.052)

A doubly stochastic rainfall model with exponentially decaying pulses

We develop a doubly stochastic point process model with exponentially decaying pulses to describe the statistical properties of the rainfall intensity process. Mathematical formulation of the point process model is described along with second-order moment characteristics of the rainfall depth and aggregated processes. The derived second-order properties of the accumulated rainfall at different aggregation levels are used in model assessment. A data analysis using 15 years of sub-hourly rainfall data from England is presented. Models with fixed and variable pulse lifetime are explored. The performance of the model is compared with that of a doubly stochastic rectangular pulse model. The proposed model fits most of the empirical rainfall properties well at sub-hourly, hourly and daily aggregation levels