Announcements

Upcoming events for 2014

Further information will be given as soon as they are available.

Bethe Colloquium by Prof. Antonio Masiero

April 2014
Masiero

April's Bethe Colloquium will take place on April 24th (3:15 pm) in Hörsaal I:

  • Antonio Masiero (INFN, Padua)
  • The Early Universe and LHC: 2 Accelerators for 1 New Physics
  • Hörsaal I, Physikalisches Institut

Abstract: The discovery of the Higgs boson (LHC) and the results on the cosmic background radiation radiation (early Universe) have assessed the validity of the GSW Standard Model of particle physics and the hot Big Bang ΛCDM Standard Model of cosmology. Yet, there are quite a few, but important, pieces of evidence that new physics beyond such Standard Models exists: neutrino masses, dark matter, cosmic matter-antimatter asymmetry, primordial inflation, dark energy. Unfortunately, there's no clear clue on the mass scale of the new particles/interactions associated with such new physics. Strong, though debatable, arguments (related to the fine-tuning of fundamental parameters connected to the Higgs boson mass and the unification of fundamental interactions) point to a new physics mass scale accessible to the LHC and with relevant implications for the early Universe dynamics. I' ll review the three-fold approach (high-energy and high-intensity machines, astroparticle physics) hunting for such (low-energy) new physics focusing, as an explicit example, on the probes of the virtual presence of new particles in very rare phenomena with lepton flavor violation.

Bethe Colloquium by Prof. Georgy Shlyapnikov

May 2014
Shlyapnikov

May's Bethe Colloquium will take place on May 22nd (3:15 pm) in Hörsaal I:

  • Georgy Shlyapnikov (LPTMS, Orsay)
  • Many-body physics with quantum gases in disorder
  • Hörsaal I, Physikalisches Institut

Abstract: I will give a brief introduction to the physics of ultracold atoms in random potentials and show that ultracold quantum gases open a wide avenue to study how the interaction between particles influences their localization and transport properties. This subtle question was crucial for electrons in solids and now it appears in a new light in the systems of disordered ultracold neutral atoms.
I then discuss two examples related to the interaction-induced many-body localization-delocalization transition. The first one concerns weakly interacting one-dimensional disordered bosons, where we have a non-conventional finite temperature phase transition between two distinct states: fluid and insulator, and I describe the phase diagram. The second example is related to interacting bosons in a quasiperiodic one-dimensional potential, which is a superposition of an initial strong lattice and superimposed shallow incommensurate lattice. This system is intermediate between the true disorder and regular lattice and I will show that the many-body localization-delocalization transition in this system leads to a remarkable result. Namely, in a wide range of parameters an increase in temperature favors the insulator state. Thus, one has an anomalous ''freezing with heating'' behavior.