• Tuesday 12 November 2019 at 10.15 in A315: Oscar Henriksson (Helsinki)
    Finite density gauge theories and brane instabilities
    Abstract: At finite density, gauge theories such as QCD can display interesting phases such as color superconductivity. Through gauge/gravity duality, finite density gauge theories can have a geometric realization as spinning or charged branes in a higher-dimensional spacetime. I will review some relevant aspects of gauge/gravity duality, and then discuss how it can be used to describe strongly coupled versions of some gauge theory phases.
  • Wednesday 13 November 2019 at 10.15 in A315: Heerak Banerjee (Kolkata)
    Nondecoupling supersymmetry and an Lμ−Lτ gauge boson at Belle-II
    Abstract: We find that the radiative contribution of charged sleptons to the γ−Z ′kinetic mixing is nondecoupling in the presence of a gauged U(1)Lμ−Lτ symmetry, depending logarithmically on the ratio (r) of stau to smuon masses. The signal process, e+e−→γZ′→γ+E/ at Belle-II arises through kinetic mixing in this case. Considering the constraints on gauged U(1)Lμ−Lτ models, we show that any significant excess in all but the highest photon energy bin would be a smoking gun for such heavy scalar fields in SUSY coupling to Z′. This process can probe large swathes of the r vs gX parameter space as well as the MZ′−gX parameter space still allowed in gauged U(1)Lμ−Lτ models for superheavy sparticles.
  • Tuesday 19 November 2019 at 10.15 in A315: Viljami Leino (Munich)
    Lattice constraints to heavy quark diffusion coefficent
    Abstract: TBA
  • Thursday 21 November 2019 at 10.15 in A315: Varun Sethi (Delhi U)
    TBA Abstract: TBA
  • Tuesday 26 November 2019 at 10.15 in A315: Karapet Mkrtchyan (Pisa)
    The problem of interacting Lagrangian for higher-spin gravity and the progress in three dimensions
    Abstract: I shall review the general problem of constructing action for higher-spin gravity ( a massless with spin bigger or equal to 2 fields, in addition to the metric graviton and lower spin fields) theories in arbitrary space-time dimensions, and comment in detail on the recent progress in constructing Lagrangian interactions for massless bosonic fields of arbitrary spin in three dimensions.
  • Thursday 28 November 2019 at 10.15 in A315: Jorinde van de Vis (DESY)
    Abstract: TBA
  • Thursday 5 December 2019 at 10.15 in A315: Andreas Schmitt (Southampton)
    Abstract: TBA
  • Thursday 12 December 2019 at 10.15 in A315: Javier Mas (Santiago de Compostela)
    Abstract: TBA
  • Thursday 19 December 2019 at 10.15 in A315: Wilke van der Schee (CERN)
    Abstract: TBA
  • Tuesday 11 February 2020 at 10.15 in A315: Chris Rosen (Imperial College, London)
    Abstract: TBA
  • Tuesday 26 May 2020 at 10.15 in A315: Murray Moinester (Tel Aviv)
    Pion Polarizabilities
    Abstract: The electric απ and magnetic βπ charged pion polarizabilities characterize the induced dipole moments of the pion during γπ Compton scattering. Pion polarizabilities affect the shape of the γπ Compton scattering angular distribution. By crossing symmetry, the γπ→γπ amplitudes are related to the γγ→ππ amplitudes. Dispersion relations (DR) describe how charged pion polarizabilities contribute to both γγ → π+π- and γγ → π0π0 reactions. A stringent test of chiral perturbation theory (ChPT) is possible by comparing the experimental polarizabilities with ChPT predictions. The combination (απ-βπ) has been measured by: (1) radiative pion Primakoff scattering πZ → πZγ at CERN COMPASS, (2) two-photon pion pair production γγ→ππ at SLAC PEP Mark-II, (3) radiative pion photoproduction γp→ γπn at Mainz MAMI. COMPASS and Mark-II (but not Mainz) polarizabilities are in good agreement with ChPT predictions; and by DRs, with DESY Crystal Ball γγ → π0π0 data. A pion polarizability status report is presented, following the review by S. Scherer and M. Moinester for IJMPA.

      Hopefully the up to 50 min + 10 min discussion long seminar/colloquium will be understandable to a wide audience.
      Contacts: Keijo Kajantie (keijo kajantie at helsinki fi) [ HIP seminar],
      Sofie Koksbang (sofie koksbang at helsinki fi) [cosmo seminar]

      For older seminars, click Seminar Archive on top of page

      Other related seminars

      Friday 10-12 seminar series in A315:Astrophysics seminar.
      Mathematical Physics Seminar and Workshop series Wed 14-16 in Exactum C123.