Measurements of photo-nuclear jet production in Pb plus Pb collisions with ATLAS

Ultra-peripheral heavy ion collisions provide a unique opportunity to study the parton distributions in the colliding nuclei via the measurement of photo-nuclear jet production. An analysis of jet production in ultra-peripheral Pb+Pb collisions at √sNN = 5.02 TeV performed using data collected with the ATLAS detector in 2015 is described. The data set corresponds to a total Pb+Pb integrated luminosity of 0.38 nb−1. The ultra-peripheral collisions are selected using a combination of forward neutron and rapidity gap requirements. The cross-sections, not unfolded for detector response, are compared to results from Pythia Monte Carlo simulations re-weighted to match a photon spectrum obtained from the STARlight model. Qualitative agreement between data and these simulations is observed over a broad kinematic range suggesting that using these collisions to measure nuclear parton distributions is experimentally realisable

Measurements of photo-nuclear jet production in Pb + Pb collisions with ATLAS

Ultra-peripheral heavy ion collisions provide a unique opportunity to study the parton distributions in the colliding nuclei via the measurement of photo-nuclear jet production. An analysis of jet production in ultra-peripheral Pb+Pb collisions at √sNN = 5.02 TeV performed using data collected with the ATLAS detector in 2015 is described. The data set corresponds to a total Pb+Pb integrated luminosity of 0.38 nb⁻¹. The ultra-peripheral collisions are selected using a combination of forward neutron and rapidity gap requirements. The cross-sections, not unfolded for detector response, are compared to results from Pythia Monte Carlo simulations re-weighted to match a photon spectrum obtained from the STARlight model. Qualitative agreement between data and these simulations is observed over a broad kinematic range suggesting that using these collisions to measure nuclear parton distributions is experimentally realisable

Heavy Ion Results from ATLAS

These proceedings provide an overview of the new results obtained with the ATLAS detector at the LHC, which were presented in the Quark Matter 2017 conference. These results were covered by twelve parallel talks, one flash talk and eleven posters. These proceedings group these results into five areas: initial state, jet quenching, quarkonium production, longitudinal flow dynamics, and collectivity in small systems

Trans Fatty Acids in Dietary Fats and Oils from 14 European Countries: The TRANSFAIR Study

The fatty acid composition of dietary fats and oils from 14 European countries was analyzed with particular emphasis on isomerictransfatty acids. The proportion oftransfatty acids in typical soft margarines and low-fat spreads ranged between 0.1 and 17% of total fatty acids and that ofcis-unsaturated fatty acids between 55 and 81%. Hard household margarines and industrial fats for cooking and baking (shortenings) had slightly higher proportions oftransfatty acids and highest amounts, up to 50%, were found in fats for deep frying. Vegetable oils contained only small amounts oftransfatty acids, usually less than 1%. Isomers of C18:1 comprised up to 94% of thetransfatty acids in hardened vegetable oils and 52-68% in butter, whereas hardened fish oils showed a more even distribution oftransmonoenoic fatty acids between C16:1 and C22:1, and C18:1 isomers contributed by 28-42% to totaltransfatty acids. Fat spreads with very low content (<1%) oftransfatty acids were found in all but one of the countries, and a general tendency to products lower intransfatty acids was observed in most countries for soft margarines and low-fat spreads but not for industrial fats and fat products for cooking and frying. The fatty acid composition of the spreads indicated that both C12-16 saturated fatty acids andcis-unsaturated fatty acids had been used to replacetransfatty acids in the low-transfatty acid products in the different countries but the use of increased amounts of stearic acid was very limited