XLIX Arbeitstreffen Kernphysik 2018

"Haus des Gastes" in Schleching, Schulstraße 4

"Haus des Gastes" in Schleching, Schulstraße 4

Tel. 08649-220

The 'Arbeitstreffen Kernphysik' is a yearly meeting of members of German and international experts on nuclear science which goes back to 1970. The aim is to provide a regular review of progress in various subareas of nuclear science and to use this occasion to introduce young students and postdocs into the field.

The meeting is by invitation only and organized by the Schleching Organizing Committee, currently consisting of:

Peter Braun-Munzinger (chair)
Burkhard Kaempfer
Ulf Meißner
Stephan Paul
Jochen Wambach

  • Adrian Koenigstein
  • Andreas Samberg
  • Andreas Schaefer
  • Ante Bilandzic
  • Burkhard Kämpfer
  • Carlo Ewerz
  • Christian Northe
  • Christoph Rosner
  • Cristina Morales
  • Florian Kaspar
  • Frederic Brünner
  • Frederik Beaujean
  • Igor Danilkin
  • Jan Rijneveen
  • Jiajun Wu
  • Joakim Nystrand
  • Jochen Wambach
  • Johanna Erdmenger
  • Johanna Stachel
  • Johannes Knaute
  • Karin Stix
  • Karol Kovarik
  • Katarzyna Wichmann
  • Martin Ammon
  • Mesut Arslandok
  • Michael Betancourt
  • Michael Florian Wondrak
  • Michael Klasen
  • Nicolas Wink
  • Nina Miekley
  • Nora Rijneveen
  • Paul Wittmer
  • Peter Braun-Munzinger
  • Peter Plößl
  • Philipp Napiralla
  • Raimond Abt
  • Rainer Santo
  • Rainer Schicker
  • Sebastian Waeber
  • Stephan Paul
  • Thomas Luu
  • Thomas Poeschl
  • Ulf Meißner
  • Urs Wiedemann
  • Vadim Guzey
    • 1
      Main Speaker
      Speaker: Andreas Schäfer
    • 10:15 AM
    • 2
      Main Speaker
      Speaker: Tom Luu
    • 12:00 PM
      free time
    • 3
      The proton structure from DIS at HERA and the role of charm quarks and higher twist

      The Deep Inelastic Scattering data from HERA are a core of every extraction of parton densities in the proton. The final combination of the H1 and ZEUS data has been done and presents a sample of very precise and well understood measurements, with a detailed knowledge of systematic uncertainties and correlations. It may be used in QCD global analysis that go beyond determination of the proton structure - like estimation of heavy quark masses and their scale dependence, measuring of electroweak couplings, searches for contact interactions or studies of the low-x higher twist effects. The inclusive HERA measurements will be presented and some of the mentioned above analysis will be explain in details.

      Speaker: Katarzyna Wichmann (DESY Hamburg)
      • a) The proton structure from DIS at HERA and the role of charm quarks and higher twist
        Speaker: Katarzyna Wichmann (DESY Hamburg)
      • b) The past and future role of DIS in nuclear PDFs

        In this talk, I will review the current status of nuclear PDFs,
        focusing on the one hand on the importance of the DIS for the
        nuclear PDFs and on the other hand on the new data coming from
        LHC. In the outlook I will comment on the impact of the planned
        electron-ion collider on nuclear PDFs.

        Speaker: Karol Kovarik (U Münster)
    • 4
      The past and future role of DIS in nuclear PDFs

      In this talk, I will review the current status of nuclear PDFs,
      focusing on the one hand on the importance of the DIS for the
      nuclear PDFs and on the other hand on the new data coming from LHC. In the outlook I will comment on the impact of the planned electron-ion collider on nuclear PDFs.

      Speaker: Karol Kovarik (U Münster)
    • 6:00 PM
    • 5
      Hydrodynamics and non-equilibrium dynamics - new insights from holography
      Speaker: Martin Ammon (Max-Planck Institute for Physics)
    • 6
      Constraining eta/s of Quark-Gluon Plasma with anisotropic flow measurements at LHC
      Speaker: Ante Bilandzic (Technische Universitaet Muenchen (DE))
    • 7
    • 8
      Main Speaker
      Speaker: Johanna Erdmenger
    • 10:15 AM
    • 9
      Main Speaker
      Speaker: Andreas Schäfer
    • 12:00 PM
      free time
    • 10
      Bayesian Methods in Nuclear Structure Physics

      The principle of Bayesian inference is used in many di?erent ?elds of science, e.g. medicine
      and computer science. The foundation of Bayesian inference lies in Bayes' theorem, which o?ers
      a powerful alternative method for data analysis. Nevertheless, Bayesian inference is still rather
      unpopular in ?elds like nuclear structure physics, where very sensitive detector systems are needed.
      -spectroscopy, one of the essential experimental tools of nuclear structure physics, the state-of-
      the-art detector systems are highly segmented High-Purity Germanium detectors like the Advanced
      GAmma Tracking Array AGATA. Due to AGATA's Germanium shell without any Compton-
      -ray tracking algorithms are needed. The mathematical problem these
      -ray tracking
      algorithms are based on, forms a perfect example case for the bene?ts of Bayesian inference over
      standard statistical inference methods.
      Using basic terms of probability theory, a short introduction into Bayesian inference is given and essential principles are presented. In addition, a how-to approach of Bayesian inference to the principle of -ray tracking is shown in the form of the Fuzzy Bayes Tracking algorithm. Possible di?culties, as well as bene?ts of Bayesian inference are elaborated in detail.

      Speaker: Philipp Napiralla
    • 11
      4. Reconstruction techniques for a space-based compact tracking calodimeter

      To precisely characterize the dose astronauts receive during their missions, it is essential to measure the radiation environment omnidirectionally. To this aim, we developed an omnidirectional particle detector and implemented and compared several online and offline algorithms for particle-parameter extraction: A Bayesian filter, a Markov chain, and neural networks trained on Monte Carlo data. In the talk, we will review the different methods, their use cases, and their performances for our setup.

      Speaker: Thomas Pöschl
    • 6:00 PM
    • 12
      nPDFs at small x and exclusive photoproduction of J/psi in UPCs at the LHC

      Nuclear parton distribution functions (nPDFs) are fundamental quantities of QCD, which describe the structure and response of nuclei in such hard processes as deep inelastic lepton-nucleus scattering, hadron-nucleus lepton pair production (Drell-Yan process), inclusive production of gauge bosons in proton-nucleus collisions, and many more.
      Nuclear PDFs are determined indirectly by fitting to these data employing the QCD factorization theorems and evolution equations. However, the resulting nPDFs are extracted with significant uncertainty, especially at small x, where nPDFs are expected to be suppressed compared to the sum of PDFs of the nucleon by nuclear shadowing (x is the light-cone momentum fraction of the nucleus momentum carried by the parton). As an alternative method, I will discuss a leading-twist dynamical model of nuclear shadowing, where nPDFs at small x result from multiple diffractive interactions with nucleons of the nuclear target. I will then explain that exclusive photoproduction of J/psi vector mesons on nuclei in Pb-Pb ultraperipheral collisions (UPCs) at the LHC gives an opportunity to probe and constrain the gluon distribution in nuclei at small x. Our analysis demonstrates that these data give evidence of the large gluon nuclear shadowing, which agrees with the leading-twist model and the EPS09 nPDFs.
      Perspectives to further constrain nPDF using UPCs at the LHC will also be discussed.

      Speaker: Vadim Guzey (PNPI Gatchina)
    • 13
      Exclusive resonance production at hadron colliders

      An overview of exclusive production of low-mass resonances at hadron colliders is presented. The data taken at the ISR, TEVATRON, RHIC and LHC are reviewed, and the physics interest in analyzing such reaction channels is discussed. In particular, I will focus on the status of glueball states, and their possible identification in exclusive production in proton-proton collisions at the LHC.

      Speaker: Rainer Schicker (U Heidelberg)
    • 14
      The energy frontier for electromagnetic interactions - Ultra-peripheral collisions at the LHC
      Speaker: Joakim Nystrand (University of Bergen (NO))
    • 10:15 AM
    • 15
      Speaker: Urs Wiedemann (CERN)
    • 12:00 PM
      free time
    • 16
      Seminar II
      Speaker: Frederik Beaujean (LMU Munich)
    • 6:00 PM
      free time
    • 17
      Evening Lecture: Gibt es bewohnbare Planeten? Und wie kommen wir dort hin?

      Seit über 20 Jahren sind Planeten jenseits unseres Sonnensystems bekannt. Einige wurden sogar als bewohnbar bezeichnet – doch was bedeutet dies? Welche Form von Leben erwarten wir dort? Mit solchen Themen befasst sich die Astrobiologie, ausgehend von dem, was wir über Leben auf Erden wissen und extrapolierend anhand unseres Wissens über Biologie, Chemie und Physik. Damit kann dann erforscht werden, welche Orte im Sonnensystem bewohnbar sein könnten. Und mit nun über dreitausend bekannten Planeten jenseits unseres Sonnensystems stellt sich die Frage, ob es auch dort Leben geben könnte. Kühner wird es, wenn wir uns die Frage stellen, ob wir jemals zu diesen Planeten reisen könnten.

      Speaker: Markus Kissler-Patig
    • 9:00 AM
      free time
    • 18
      Main Speaker
      Speaker: Tom Luu
    • 10:15 AM
    • 19
      Main Speaker
      Speaker: Johanna Erdmenger (Max Planck Institute for Physics)
    • 12:00 PM
      free time
    • 20
      MPIs: Double parton distributions and how to constrain them using sum rules

      In my talk, I will first present a short overview of the basics of multiple partonic interactions (MPIs), with the main focus on double parton scattering (DPS), and discuss factorization for double parton scattering. One of the building blocks of factorised DPS cross sections are the DPS counterpart of
      regular parton distributions, the double parton distributions (DPDs), which, as of now, could not be extracted from experimental data. In order to still be able to calculate DPS cross sections a possible solution is to try and model
      realistic DPDs using the requirement that DPDs should fulfil certain physical constraints. One particularly useful constraint is provided by DPD momentum and valence number sum rules which sensible DPDs should fulfil, in close analogy to
      the well known PDF sum rules. I will discuss how these sum rules can be used to constrain the parameters in a DPD model ansatz.

      Speaker: Peter Plößl (U Regensburg)
    • 21
      Hadronic light-by-light scattering and the muon's (g-2)

      In my talk, I will present our recent dispersive analysis of the
      gamma gamma -> pipi, pieta processes from the threshold up to 1.4 GeV in the two photon invariant mass. These amplitudes serve as important input to constrain the hadronic piece of light-by-light scattering contribution to (g-2) and support the current experimental program at BESIII. As well, I will present an application of the light-by-light scattering sum rules to the gamma gamma-production of mesons in light of the new data by the Belle Collaboration on the transition form factors.

      Speaker: Igor Danilkin (U Mainz)
    • 6:00 PM
    • 22
      Glueballs and Holography
      Speaker: Frederic Bruenner
    • 23
      Heavy Quarks in Strongly Coupled Plasmas
      Speaker: Andreas Samberg
    • 24
      Main Speaker
      Speaker: Johanna Erdmenger
    • 10:15 AM
    • 25
      Main Speaker
      Speaker: Andreas Schäfer
    • 12:00 PM
      free time
    • 26
      Applying Restricted Harmonic-Mean Integration to High-Dimensional Problems

      Physics analyses often involve complex statistical models. When more than one model is available, it may be desirable to choose the "best" one of them. In a Bayesian setting, one decides by comparing model evidences.
      For models with large numbers of parameters, calculating the evidence involves high-dimensional integrals.
      Modern Monte Carlo methods can sample from high-dimensional probability density functions.
      We apply restricted harmonic-mean integration with these samples as a way of calculating model evidences.
      We present the method and where it is applicable, estimate its uncertainties and discuss pathological cases and possible extensions.

      Speaker: Florian Kaspar
    • 27
      Detector response simulation of the ALICE TPC

      The ALICE Time Projection Chamber (TPC) is the main tracking and particle identification (PID) detector of ALICE at the CERN-LHC. It was designed for multiplicities of up to
      20,000 primary and secondary charged particles emerging from a single central Pb-Pb collision. The PID in the TPC is calculated from the specific energy loss measurement
      (dE/dx), which is derived from the pulse height distribution of charged particle tracks.
      Accurate simulation of the dE/dx response of the TPC plays a significant role in the testing of the reconstruction and analysis algorithms, in particular in the high multiplicity environment of Pb-Pb collisions, and eventually in the quality of the final physics results of ALICE. In this presentation, a novel approach for the detector response simulation of the TPC and its impact on the PID performance will be presented.

      Speaker: Mesut Arlsandok
    • 6:00 PM
    • 28
      Baryon electromagnetic form factors at BESIII

      The Beijing Spectrometer (BESIII) at the Beijing Electron Positron Collider in China is an excellent laboratory for the measurement of baryon electromagnetic form factors in the time-like kinematic region.
      The collider is running at center-of-mass energies between 2.0 and 4.6 GeV, allowing the study of e+e- annihilations into pairs of baryons like proton-antiproton, neutron-antineutron and hyperons in the SU(3) spin 1/2 octet and spin 3/2 decuplet. Furthermore, the emission of initial-state radiation by the beams allows also to access kinematic regions below the actual center-of-mass energy of the collider, making possible the measurement of baryon form factors also at the production threshold.
      In this talk I will review some of the channels currently being studied by the BESIII collaboration.

      Speaker: Cristina Morales (U Mainz)
    • 29
      Nucleon excited states from lattice QCD

      The spectrum from lattice QCD is one of the important tools to understand the properties of hadron. By using the Hamiltonian effective field theory (HEFT) method, we develop an approach for relating the nucleon excited states extracted from lattice QCD and the nucleon resonances of experimental data. The approach opens a new window for the study of experimentally-observed resonances from the
      first principles of lattice QCD calculations. With this pproach, one not only describes the spectra of lattice-QCD eigenstates through the eigenvalues of the finite-volume Hamiltonian matrix, but one also learns the composition of the lattice-QCD eigenstates via the eigenvectors of the Hamiltonian matrix. Therefore, the approach reveals the composition of the resonances observed in Nature. In this
      presentation, I will focus on recent breakthroughs in our
      understanding of the structure of the N(1535), N(1440) and
      Lambda(1405) resonances using this method.

      Speaker: Jia-Jun Wu (U Bonn)
    • 30
      Review I
      Speaker: Michael Klasen
    • 31
      Non-local observables in AdS/CFT
      Speaker: Nina Miekley
    • 32
      Aspects of kinematic space
      Speaker: Raimond Abt
    • 10:15 AM
    • 33
      Main Speaker
      Speaker: Thomas Luu (Forschungszentrum Jülich)
    • 12:00 PM
      free time
    • 34
      Shear Correlations from Initial Stages of Particle Collisions via Holographic Thermalization
      Speaker: Michael Florian Wondrak (Johann Wolfgang Goethe-Universität Frankfurt am Main)
    • 35
      Colliding asymmetric shocks in- and finite coupling corrections to AdS/CFT
      Speaker: Sebastian Waeber
    • 36
      Worldline holography
      Speaker: Adrian Koenigstein
    • 6:00 PM
    • 37
      Reconstruction the gluon

      The reconstruction of the gluon spectral function from (noisy) Euclidean data is considered.
      As a novelty, all available information about the Landau gauge propagator is taken into account.
      This includes the IR and UV asymptotics as well as the normalization.
      First results are presented, utilizing all prior information in combination with a state of the art Bayesian Reconstruction.

      Speaker: Nicolas Wink
    • 38
      Holographic QCD phase diagram and entanglement entropy
      Speaker: Johannes Knaute
    • 39
      Speaker: Michael Betancourt (California Institute of Technology (CALTECH))
    • 10:15 AM
    • 40
      Reviews II + III