GK Seminars WS 15/16

Tue 03.11.2015, 16.30 h

W. Lohmann (DESY)

Beam Radiation Instrumentation and Luminosity - the BRIL project

 

Tue 10.11.2015, 16.30 h

J. Albrecht (Dortmund)

Search for New Physics and News about Old Physics

Abstract:
The talk discusses recent results from the LHCb collaboration. A focus is set on searches for new phenomena in rare Flavour Changing Neutral Current processes. These measurements show effects that, if confirmed, would be a signature of new interactions at the TeV scale. Recent results on exotic hadrons, including evidence for four and five quark states, are also discussed.

 

Tue 24.11.2015, 16.30 h

R. Catena (Göttingen)

Effective theory of dark matter-nucleon interactions

Abstract:
The experimental technique known as direct detection (DD) will play a pivotal role in shedding light on the nature of dark matter during the next decade. It searches for nuclear recoil events induced by the non-relativistic scattering of Milky Way dark matter particles in low-back ground detectors. At the same time, neutrino telescopes (NT) are
complementary to direct detection experiments, as they probe dark matter-nucleon interactions in different environments. An effective field theory approach is a solid strategy to interpret both DD and NT experiments when the momentum transferred in the dark matter scattering by nuclei is small compared to the mass of the particles mediating the interaction. In this talk I compare the non-relativistic effective theory of one-body dark matter-nucleon interactions to current dark matter direct detection experiments and neutrino telescope observations, presenting exclusion limits on the coupling constants of the theory. In the analysis of direct detection experiments, I focus on the interference of different dark matter-nucleon interaction operators, and on predictions observable at directional detectors. Interpreting neutrino telescope observations, I use new nuclear response functions recently derived through nuclear structure calculations.

 

Tue 01.12.2015, 16.30 h

S. Ostapchenko (FIAS Frankfurt)

Constraints from LHC on simulations of nuclear interaction in Cosmic Rays

Abstract:
I shall review modern approaches to Monte Carlo treatment of high energy hadronic interactions. I'll start from discussing the underlying physics picture and proceed with describing the Reggeon Field Theory based treatment, as implemented in the QGSJET-II model. A special attention will be payed to the description of forward particle production and inelastic diffraction and example comparisons with the data from the Large Hadron Collider will be presented. Finally, I shall outline potential measurements which could discriminate between different theoretical approaches and provide important input for astrophysical studies.

 

Tue 08.12.2015, 16.30 h

P. Beltrame (Edinburgh)

How close to enlightening this dark universe? The status of dark matter direct searches

Abstract:
The discovery of Dark Matter (DM), accounting for 85% of the matter content of the Universe, has been identified as one of the most important scientific missions of the 21st century. Following precise cosmological and astronomical measurements, the question today is no longer whether DM exists, but rather: what is the nature of DM? Stable and heavy Weakly Interacting Massive Particles (WIMPs), arising naturally from extensions to the Standard Model (SM) of particle physics, are compelling candidates, supported by both astrophysical and particle physics considerations. WIMPs may be produced at accelerators and their presence inferred through missing energy signatures, or their annihilation products emitted from astrophysical sources may be identified providing indirect detections. Such techniques are complementary to low energy rare-event search experiments located in deep underground laboratories which offer the only direct means, detecting galactic WIMPs scattering off the nuclei of the active target
material. In the talk I will present the current status of the direct searches, introducing the various technologies employed, along with their potential and limitations. Special attention will be also given to the future prospects, challenges and to alternative yet well-motivated theories which propose non-WIMP particles as the DM candidate.

 

Tue 22.12.2015, 16.30 h

F. Sanchez (IFAE Barcelona)

T2K: present results and challenges

Abstract:
The long base line neutrino oscillation experiment T2K has recently presented the antineutrino oscillation results in its research for CP violation in the neutrino sector. Neutrino results showed a faint hint for maximal CP violation in combination of the reactor neutrino results. The antineutrino results are the first attempt from T2K to measure the broken symmetry directly. Both results will be presented and the challenges ahead  to discover CP violation will be discussed

 

Tue 19.01.2016, 16.30 h

L. Ludhova (RWTH und FZ Jülich)

Solar and Geo Neutrinos

Abstract:
Neutrino physics continues to be a very active research field, full of opened fundamental questions reaching even beyond the SM and towards possible new physics. Solar neutrinos have played a fundamental historical role in the discovery of the phenomenon of neutrino oscillations and thus non-zero neutrino mass. Even today, the study of solar neutrinos provides an important insight both into the neutrino as well as into the stellar and solar physics. Neutrino geoscience is a newly born interdisciplinary science having as its main aim determination of the Earth’s radiogenic heat through measurement of antineutrinos released in the decay of long-lived radioactive elements inside the Earth (geoneutrinos). The seminar will cover the status-of-art of the present day solar and geo neutrinos physics, as well as a more detailed review of the recent results from Borexino experiment, 300 ton liquid scintillator detector placed deep underground in the Laboratori Nazionali del Gran Sasso, near L’Aquila town in central Italy.

 

Tue 26.01.2016, 16.30 h

J. Tjus (Bochum)

Cosmic Accelerators and IceCube neutrinos