Workshop on nuclear Parton Distribution Functions

Europe/Paris
Auditorium M. Vivargent (LAPTH)

Auditorium M. Vivargent

LAPTH

9, chemin de Bellevue 74941 Annecy-le-Vieux France
Christophe Furget (LPSC), François Arleo (LAPTH), Ingo Schienbein (LPSC), Magali Estienne (Subatech)
Description
The workshop is intended to discuss informally various aspects of nuclear parton distribution functions (nPDF). Several topics could be discussed, in particular: * Current knowledge on nPDF, status on global fit analyses * Uncertainties and consequences on various observables (prompt photons, heavy quarkonia, jets, ...) * Future constraints on nPDF in p-A and A-A collisions at the LHC * Link between nPDF and saturation Ample time will be given for informal discussions. One of the goals of the workshop is to federate the activities of various groups in France. In particular it aims at enhancing exchanges between theorists and experimentalists on this topic. It is partly funded by the CNRS program "Projets Exploratoires Pluridisciplinaires - Physique Théorique et ses Interfaces" submitted by the organisers of the workshop.
Participants
  • Andry Rakotozafindrabe
  • christophe furget
  • Cynthia Hadjidakis
  • David d'Enterria
  • Enrico Scomparin
  • Francois Gelis
  • François Arleo
  • Fred Olness
  • Frédéric Fleuret
  • Gustavo Conesa Balbastre
  • Ingo Schienbein
  • Jean-Philippe Lansberg
  • Ji Young Yu
  • Jorge Casalderrey Solana
  • José Guilherme Milhano
  • Julien Faivre
  • Karol Kovarik
  • Lamia Benhabib
  • Magali Estienne
  • Nestor Armesto
  • Nicolas Matagne
  • Paloma Quiroga-Arias
  • Raphaelle Ichou
  • Roberta Arnaldi
  • Sarah Porteboeuf
  • Sebastien Gadrat
  • Swensy Jangal
  • Thierry Gousset
  • Tzvetalina Stavreva
  • Éric Voutier
Support
  • Monday, 22 February
    • 09:30 12:00
      nPDF and saturation Auditorium M. Vivargent

      Auditorium M. Vivargent

      LAPTH

      9, chemin de Bellevue 74941 Annecy-le-Vieux France
      slides
      • 09:30
        Gluon saturation and nuclear PDFs 50m Auditorium M. Vivargent

        Auditorium M. Vivargent

        LAPTH

        9, chemin de Bellevue 74941 Annecy-le-Vieux France
        I will discuss the topic of gluon saturation at small x, and what it implies for the use of nuclear parton distribution functions.
        Speaker: Dr Francois Gelis (IPhT)
        Slides
      • 10:20
        break 30m Galerie (LAPTH)

        Galerie

        LAPTH

        9, chemin de Bellevue 74941 Annecy-le-Vieux France
      • 10:50
        Non-linear QCD meets data: from proton to nuclei 35m Auditorium M. Vivargent

        Auditorium M. Vivargent

        LAPTH

        9, chemin de Bellevue 74941 Annecy-le-Vieux France
        Speaker: José Guilherme Milhano (CENTRA-IST & CERN-PH-TH)
      • 11:25
        Saturation effects in p-A collisions at the LHC with the ALICE muon spectrometer 35m Auditorium M. Vivargent

        Auditorium M. Vivargent

        LAPTH

        9, chemin de Bellevue 74941 Annecy-le-Vieux France
        At very high energies or small values of Bjorken x, the increase of parton density in hadronic matter is expected to lead to a saturated partonic distribution regime. It has been suggested that such an initial state effect, expected to be present before the Quark Gluon Plasma phase, has been observed in heavy-ion collisions at RHIC energies. The study of high partonic density effects in QCD can be formulated in terms of an effective field theory, the Color Glass Condensate (CGC). This theoretical framework is used in particular to describe the new kinematic regime that is accessible at the LHC in p-A collisions. In this talk the principal features of the high density regime will be described, together with a brief look at the experimental observations for saturation effects obtained at RHIC energies. Special attention will be given to the prospects of observing saturation effects at the LHC in p-A collisions with the ALICE experiment. In particular, heavy flavour and quarkonia production will be discussed in terms of physics performance studies of the ALICE Muon Forward Spectrometer.
        Speaker: Cynthia Hadjidakis (IPN)
        Slides
    • 12:00 14:15
      Lunch 2h 15m Galerie

      Galerie

      LAPTH

      9, chemin de Bellevue 74941 Annecy-le-Vieux France
    • 14:15 18:05
      Heavy flavour Auditorium M. Vivargent

      Auditorium M. Vivargent

      LAPTH

      9, chemin de Bellevue 74941 Annecy-le-Vieux France
      • 14:15
        "Quarkonia as tools ?" : further experimental needs 50m
        Speaker: Dr Jean-Philippe Lansberg (Ecole Polytechnique - CPhT)
      • 15:05
        Cold Nuclear Matter effects on J/psi production with extrinsic transverse momentum 30m
        %----------------------------------------------------------------------------- % THIS IS THE CONFERENCE TEMPLATE % % Do not modify the dimensions of the page % No paragraph indent or paragraph skip % \documentclass[11pt]{article} % \pagestyle{empty} \setlength{\topmargin}{-0.3in} \setlength{\textheight}{9.9in} \setlength{\oddsidemargin}{-0.1in} \setlength{\textwidth}{6.5in} \parindent=0pt \parskip=0pt % % list of words for which Latex has wrong hyphenation points %\hyphenation{ave-ra-ge un-der-lying} % \begin{document} % {\small \it Workshop on Nuclear Parton Distribution Functions, LAPTH Annency, Feb. 22 - 23, 2010} \vspace{0.5in} \centerline{\Large \bf Cold Nuclear Matter effects on $J/\psi$ production} \centerline{\Large \bf with extrinsic transverse momentum} \vspace{8pt} \centerline{ {\bf E.~G.~Ferreiro}$^{\rm a}$, {\bf F.~Fleuret}$^{\rm b}$, {\bf J.~P.~Lansberg}$^{\rm c}$ and {\bf A.~Rakotozafindrabe}$^{\rm d}$} \vspace{8pt} \centerline{\small$^{\rm a}$Departamento de F\'{\i}sica de Part\'{\i}culas, Universidade de Santiago de Compostela }\centerline{15782 Santiago de Compostela, Spain, {\it elena@fpaxp1.usc.es}} \vspace{8pt} \centerline{\small$^{\rm b}$ Laboratoire Leprince Ringuet, \'Ecole Polytechnique, {CNRS-IN2P3}, } \centerline{91128 Palaiseau Cedex, France, {\it fleuret@llr.in2p3.fr}} \vspace{8pt} \centerline{\small$^{\rm c}$ Centre de Physique Th\'eorique, \'Ecole Polytechnique, {CNRS}, } \centerline{91128 Palaiseau Cedex,France, {\it lansberg@cpht.polytechnique.fr}} \vspace{8pt} \centerline{\small$^{\rm d}$ IRFU/SPhN, CEA Saclay }\centerline{91191 Gif-sur-Yvette Cedex, France, {\it andry.rakotozafindrabe@cea.fr}} \vspace{16pt} We study the Cold Nuclear Matter (CNM) effects on $J/\psi$ production, whose understanding is fundamental to evaluate the Quark Gluon Plasma or Hot Nuclear Matter effects. Two CNM effects are of particular importance: the shadowing of the initial parton distributions (PDF) due to the nuclear environment and the nuclear absorption of the $c\bar{c}$-pair. Recent theoretical works~\cite{CSM-upgrade,Upsilon-LHC,next-paper-JPhi} have emphasized that the production mechanism of the $J/\psi$ is not {\it via} a $2 \to 1$ Drell-Yan like process. This modifies the way to compute the nuclear shadowing~\cite{first-extrinsic-paper}. We will present our results in $dA$ and $AA$ collisions at RHIC energy~\cite{first-extrinsic-paper}, using several parametrizations of the nuclear PDF~\cite{paper-nPDF-comparison,second-extrinsic-paper}, and including the $p_T$-dependence of CNM effects up to intermediate values of $p_T$, which are not accessible in the usual studies. \vspace{8pt} \bibliographystyle{unsrt} \begin{thebibliography}{6} \bibitem{CSM-upgrade}H.~Haberzettl and J.~P.~Lansberg, \textit{Phys. Rev. Lett.} {\bf 100}, (2008) 032006. \bibitem{Upsilon-LHC}P.~Artoisenet, J.M.~Campbell, J.P.~Lansberg, F.~Maltoni and F.~Tramontano, \textit{Phys. Rev. Lett.} {\bf 101}, (2008) 152001. \bibitem{next-paper-JPhi}S.J.~Brodsky and J.P.~Lansberg, SLAC-PUB-13736, \textit{arXiv:0908.0754}. \bibitem{first-extrinsic-paper}E.~G.~Ferreiro, J.~P.~Lansberg, F.~Fleuret, A.~Rakotozafindrabe, \textit{Phys. Lett. B} {\bf 680} (2009) 50-55. \bibitem{paper-nPDF-comparison}E.~G.~Ferreiro, J.~P.~Lansberg, F.~Fleuret, A.~Rakotozafindrabe, \textit{arXiv:0903.4908}, Contribution to Rencontres de Moriond~2009: QCD and High Energy Interactions. \bibitem{second-extrinsic-paper}E.~G.~Ferreiro, J.~P.~Lansberg, F.~Fleuret, A.~Rakotozafindrabe, \textit{arXiv:0912.4498}. \end{thebibliography} \end{document}
        Speaker: Dr Andry Rakotozafindrabe (CEA Saclay, IRFU/SPhN)
        Slides
      • 15:35
        Gluon shadowing and J/psi suppression in p A collisions : uncertainties and constraints 30m
        Speaker: François Arleo (LAPTH)
        Slides
      • 16:05
        break 30m
      • 16:35
        The role of parton shadowing in the comparison of p-A and A-A results on J/psi suppression at SPS energies 30m
        The observation of an anomalous jpsi suppression in nucleus-nucleus collisions is one of the most important results of the SPS heavy-ion program. An essential ingredient in this result is the determination, obtained by studying p-A collisions, of cold nuclear matter effects. These effects are extrapolated to A-A collisions, determining a reference jpsi yield that is then compared with the measurements. In this article we investigate the role of parton shadowing on the determination of such a reference, and we calculate its effect for In-In and Pb-Pb collisions as a function of rapidity and centrality, for various nPDF parametrizations.
        Speaker: Dr Enrico Scomparin (INFN-Torino (Italy))
        Slides
      • 17:05
        Upsilon production in dAu collisions at RHIC 30m
        Speaker: Dr Nicolas Matagne (Université de Mons)
        Slides
      • 17:35
        Direct Photon Production In Association With A Heavy Quark Jet at Hadron and Ion Colliders 30m
        The associated production of direct photons and heavy quarks probes the gluon and heavy quark PDFs. As such this process can be used to constrain those nPDFs and to distinguish between different nPDF sets. Predictions for hadron and ion colliders (ALICE, RHIC) are shown.
        Speaker: Dr Tzvetalina Stavreva (LPSC)
        Slides
    • 20:00 22:00
      Banquet 2h Brasserie Les Européens

      Brasserie Les Européens

      LAPTH

      9, chemin de Bellevue 74941 Annecy-le-Vieux France
  • Tuesday, 23 February
    • 09:15 10:35
      Global fits Auditorium M. Vivargent

      Auditorium M. Vivargent

      LAPTH

      9, chemin de Bellevue 74941 Annecy-le-Vieux France
      • 09:15
        A Global Analysis of Nuclear PDFs and the Heavy Quark Components 50m
        We provide a brief overview of the historical developments of global analyses of nuclear PDFs incorporating heavy quarks into the PDF formalism. We then look at the various data sets which have been used to extract the proton PDF and highlight the necessity of addressing the nuclear dimension in a coherent framework.
        Speaker: Prof. Fred Olness (SMU)
        Slides
      • 10:05
        Nuclear PDF from neutrino and charged lepton data 30m
        Speaker: Dr Karol Kovarik (LPSC Grenoble)
        Slides
    • 10:35 11:00
      break 25m Galerie

      Galerie

      LAPTH

      9, chemin de Bellevue 74941 Annecy-le-Vieux France
    • 11:00 12:00
      Photons Auditorium M. Vivargent

      Auditorium M. Vivargent

      LAPTH

      9, chemin de Bellevue 74941 Annecy-le-Vieux France
      • 11:00
        Prompt Photon Production in p-A Collisions and Gluon Shadowing 30m
        We discuss the use of prompt photon production at the LHC to probe the gluon nuclear density, and more specifically the shadowing ratio G_A/G_p that one could access in foreseen p-A runs.
        Speaker: Mr Thierry Gousset (Subatech)
        Slides
      • 11:30
        How well can isolated photons constrain the gluon pdfs in the proton? 25m
        Speaker: Ms Raphaelle ICHOU (SUBATECH)
        Slides
    • 12:00 14:15
      Lunch 2h 15m Galerie

      Galerie

      LAPTH

      9, chemin de Bellevue 74941 Annecy-le-Vieux France
    • 14:15 17:25
      LHC and future facilities Auditorium M. Vivargent

      Auditorium M. Vivargent

      LAPTH

      9, chemin de Bellevue 74941 Annecy-le-Vieux France
      • 14:15
        Constraints to nuclear parton densities in an LHeC 50m
        The possibilities to constrain nuclear parton densities through the eA option of the proposed LHeC at CERN will be presented and discussed. Emphasis will be presented in quantitative constrains to DGLAP global analysis, and in the problems due to our limited knowledge of the longitudinal structure function in the nuclear case.
        Speaker: Dr Nestor Armesto (Universidade de Santiago de Compostela)
        Slides
      • 15:05
        pA collisions at LHC: a tool to constrain nuclear PDFs 30m
        pA collisions at LHC: a tool to constrain nuclear PDFs
        Speaker: Mrs Paloma Quiroga Arias (Universidade de Santiago de Compostela)
        Slides
      • 15:35
        Measuring nuclear PDFs at the LHC: a wish list 30m
        Speaker: David d'Enterria (ICREA & ICC-UB)
        Slides