Wed·Nov 5, 2014Wednesday·November 5, 2014

1. 01*

   Recent results and open questions on collective type phenomena from A-A to pp collisions

   M. Petrovici🇷🇴 · C. Andrei🇷🇴 · I. Berceanu🇷🇴 · A. Bercuci🇷🇴 · A. Herghelegiu🇷🇴 · A. Pop🇷🇴

   A review of the main results on the collective type expansion of the compressed and hot fireball formed in heavy ion collisions and some remarks to be considered when comparing multiplicity wise phenomena taking place in A-A, p-A and pp collisions, are followed by a discussion of the experimental results which seem to evidence collective type phenomena in pp collisions at $\sqrt{s}$ = 7 TeV at high charged particle multiplicity. Correlations among the kinetic freeze-out temperature, the average transverse expansion velocity and its profile, as a function of centrality and multiplicity, extracted from the fits of experimental transverse momentum spectra with an expression inspired by hydrodynamical models, estimates on Bjorken energy densities and perspectives in selecting soft and close to azimuthal isotropic events in pp collisions are presented.

   nucl-exhep-exAIP Conf.Proc.(2015)·14 citations
2. 02*

   Resummation of Jet Shapes and Extracting Properties of the Quark-Gluon Plasma

   Yang-Ting Chien🇺🇸

   Understanding the properties of the quark-gluon plasma (QGP) that is produced in ultra-relativistic nucleus-nucleus collisions has been one of the top priorities of the heavy ion program at the LHC. Energetic jets are produced and subsequently quenched in the collisions. Such jet quenching phenomena provide promising tools to probe the medium properties by studying the modification of jets due to the medium interactions. Significant modifications of jet shapes have been measured. In this talk we focus on the calculation of jet shapes in both proton-proton and lead-lead collisions using soft-collinear effective theory (SCET), with Glauber gluon interactions in the medium. Large logarithms in jet shapes are resummed at next-to-leading logarithmic (NLL) accuracy by the renormalization-group evolution between hierarchical jet scales. The medium interactions contribute as power corrections, and we calculate the modification of jet shapes at leading order in opacity with the static QGP model. Preliminary results are presented with good agreement with the recent CMS jet shape measurements.

   ↳ hep-phnucl-exnucl-thInt.J.Mod.Phys.Conf.Ser.(2015)·9 citations
3. 03*

   Comparison of nuclear data uncertainty propagation methodologies for PWR burn-up simulations

   Carlos Javier Diez (1) · Oliver Buss (2) · Axel Hoefer (2) · Dieter Porsch (2) · Oscar Cabellos (1) ((1) Universidad Politécnica de Madrid · (2) AREVA GmbH)

   Several methodologies using different levels of approximations have been developed for propagating nuclear data uncertainties in nuclear burn-up simulations. Most methods fall into the two broad classes of Monte Carlo approaches, which are exact apart from statistical uncertainties but require additional computation time, and first order perturbation theory approaches, which are efficient for not too large numbers of considered response functions but only applicable for sufficiently small nuclear data uncertainties. Some methods neglect isotopic composition uncertainties induced by the depletion steps of the simulations, others neglect neutron flux uncertainties, and the accuracy of a given approximation is often very hard to quantify. In order to get a better sense of the impact of different approximations, this work aims to compare results obtained based on different approximate methodologies with an exact method, namely the NUDUNA Monte Carlo based approach developed by AREVA GmbH. In addition, the impact of different covariance data is studied by comparing two of the presently most complete nuclear data covariance libraries (ENDF/B-VII.1 and SCALE 6.0), which reveals a high dependency of the uncertainty estimates on the source of covariance data. The burn-up benchmark Exercise I-1b proposed by the OECD expert group "Benchmarks for Uncertainty Analysis in Modeling (UAM) for the Design, Operation and Safety Analysis of LWRs" is studied as an example application. The burn-up simulations are performed with the SCALE 6.0 tool suite.

   ↳ nucl-thnucl-exAnnals Nucl.Energy(2015)·7 citations
4. 04*

   Ballistic protons in incoherent exclusive vector meson production as a measure of rare parton fluctuations at an Electron-Ion Collider

   T. Lappi🇫🇮 · H. Mäntysaari🇫🇮 · R. Venugopalan🇺🇸

   We argue that the proton multiplicities measured in Roman pot detectors at an electron ion collider can be used to determine centrality classes in incoherent diffractive scattering. Incoherent diffraction probes the fluctuations in the interaction strengths of multi-parton Fock states in the nuclear wavefunctions. In particular, the saturation scale that characterizes this multi-parton dynamics is significantly larger in central events relative to minimum bias events. As an application, we study the centrality dependence of incoherent diffractive vector meson production. We identify an observable which is simultaneously very sensitive to centrality triggered parton fluctuations and insensitive to details of the model.

   ↳ hep-phnucl-exnucl-thPRL(2015)·29 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.