Archiv 2017

Gastgeber: Melanie Schnell

Pedro de la Torre Luque - Study of cosmic neutrinos diffuse flux with Antares neutrino telescope: track channel

CFEL Molecular Physics Seminar
This project is based on the study of signals which ANTARES neutrino telescope have detected between 2007 and 2015. Firstly, an introduction about the sources of neutrinos and what we know about the origins of cosmic neutrinos is showed. Then, It will be explained the process of detection of neutrinos used by ANTARES neutrino telescope. Secondly, the analysis of the detected data in the 9 years mentioned before is carried out. The first part of the analysis consists in a comparison between detected data and simulated data will be shown for some variables, like neutrino direction or energy of them. The Monte Carlo simulated data is done in order to reproduce the observed Background and reduce it by applying cut-offs. Also the simulation of the expected signals from cosmic neutrinos is done to compare to the fitted background. The second part consists in the search of the cut-offs which will help to improve the signal/noise ratio. These cut-offs will be selected by mean of the analysis of some parameters or applying statistical methods, like Feldmann-Cousin method. Finally, the obtained signal is showed to extract conclusions. [mehr]

Yoni Toker: Watching Isolated Molecules Change Their Shape

CFEL Molecular Physics Seminar
Recently it has been shown that using two stages of ion mobility it is possible to measure isomerizations - structural changes in isolated molecules. Moreover, it is possible to measure the relative energies of different isomers and to deduce the barrier energy for each isomerization pathway. We have applied the technique to one of the most biologically important cases; that of the retinal protonated Schiff base (RPSB). RPSB is the chromophore which acts as a photon detector in every known form of animal vision. The primary step in vision is photoisomerization of the RPSB, which then activates the surrounding protein. We have studied the barrier energies for isomerizations of the RPSB and have shown them to be significantly lower than within the protein. We have also compared different derivatives of the chromophore and shown that slight changes to the structure of the chromophore, can dramatically effects its energy landscape. [mehr]
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