לוח שנה משולב

With the discovery at the LHC of the Higgs boson, the main missing block of the Standard Model is now in place. An additional LHC result of great importance is that a large new territory has been explored and no unambiguous signal of New Physics has been found.
However some new particles or interactions are required to explain a number of observed phenomena in particle physics, astrophysics, and cosmology as the neutrino masses, the baryon asymmetry of the universe, the Dark Matter and the cosmological inflation.
So far the experimental efforts have been concentrated on the discovery of new particles with masses at or above the EW scale with sizable couplings with SM particles. Another viable possibility, largely unexplored, is that these new particles are below the EW scale and have not been detected because they interact very feebly with the SM particles.
I will review the current status of the search for these new particles with masses in the MeV-GeV region at beam dump experiments currently running or proposed at CERN.

Unicellular algae have established efficient means to interact with other organisms in their environment. Especially chemical signals play an important role in this context. Algal exudates as well as intracellular metabolites can, for instance, influence feeding activity of herbivores and algal / algal interactions. But also communication of algae with the surrounding microbial community is mediated by such chemical signals. Knowledge about the nature of these signal molecules opens up possibilities to investigate their mode of action, the regulation of interactions, and even to manipulate communities. This talk highlights that efficient chemical signaling is often a highly dynamic process that can be switched on and off upon demand. Indeed, surveys based on elaborate mass spectrometric methods confirm that algae exhibit a high plasticity of metabolite production during their development and in interaction situations. This regulation opens up new avenues for the identification of signals and mechanisms of chemically mediated interactions. Using a combination of comparative metabolomics and ecological investigations even dilute signal molecules can be elucidated. In addition, microscopic gradients of metabolites are visualized and mimicked to illustrate how chemical information can structure the otherwise homogeneous aqueous environment of microbes. Overall this talk will introduce novel concepts in marine chemical ecology.

The tunnelling time problem is almost as old as quantum mechanics itself and is a highly debated subject. Time is not a quantum observable, and therefore many conflicting theories have been developed over the decades. Here we present the Feynman path integral (FPI) approach to tunnelling time, and show how it can be used to calculate tunnelling time probability amplitudes. The FPI approach also sheds new light on four best-known definitions of tunnelling times (Buttiker- Landauer, Pollak-Miller, Eisenbud-Wigner, and Larmor), which although derived using very different physical models, can also be represented as different averages using FPI tunnelling time probability amplitudes. Relation between the FPI approach, other tunnelling time definitions and the theory of weak measurement is also reviewed.

High-sensitivity searches for ``fifth forces'' can test a variety of models of new physics that produce new weakly coupled or short range (

While revisiting Klein-Gordon relativistic quantum equation for spin-0 particles, we predicted that ħ reverses its sign for negative energies. We formulated a universal symmetry rule, whereby all the parameters that couple particles to external fields reverse their sign along with ħ at a particle↔antiparticle transformation. This in particular implies anti-gravitation between matter and antimatter.
Our results suggest that the ħ-conjugation principle and related invariance may replace CPT-invariance in general relativistic quantum mechanics.