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<div class="">Hello:</div>
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<div class="">To strengthen its neutron physics research program, the Johannes Gutenberg University Mainz offers</div>
<div class="">one postdoctoral position (100 % EG13) to work on the tSPECT experiment (<a href="https://ucn.uni-mainz.de/tauspect/" class="">https://ucn.uni-mainz.de/tauspect/</a>) to measure the lifetime of the free neutron.</div>
<div class="">The lifetime of the free neutron is a key observable in low-energy tests of the Standard Model of Particle Physics (SM) with important implications throughout the evolution of the Universe. The neutron lifetime determines the ratio of 4He/H after
the primordial nucleosynthesis. And within the SM only three (low-energy) parameters are required for a highprecision description of the free neutron decay: The CKM matrix element Vud, the ratio of axial-vector and vector coupling strength gA/gV, and the free
neutron lifetime. Therefore, a precise determination of the neutron lifetime contributes to a very stringent test of the SM prediction and any deviation thereof could be a tantalizing hint to physics beyond the SM.</div>
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<div class="">The tSPECT experiment is installed at the source of ultra-cold neutrons (UCN) at JGU’s own TRIGA reactor. We follow the approach to measure the fraction of neutrons surviving for a variable storage time in a so-called neutron bottle. This bottle
is formed by a region of a magnetic field minimum surrounded by strong positive magnetic field gradients. Through the neutron’s electromagnetic interaction potential, neutrons in the low-field-seeking spin state get trapped without contact to material walls
where the spurious neutron absorption could occur. To “close” the UCN-bottle after the filling process tSPECT uses a unique approach. By applying a radio-frequency pulse, initially high-field seeking UCN are converted into the storable, low-field seeking state.
This way also the closing of the bottle happens contact-less and without the need to physically move magnet arrangements. The tSPECT experiment is currently in its commissioning phase. The postdoctoral scholar will participate in the data accumulation during
beam times and drive the efforts for detailed Monte-Carlo simulations of the experiment that will be required to understand effects that could systematically bias the extracted neutron lifetime result. Working experience with various UCN-specific MC packages
is desireable.</div>
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<div class="">Please send your application, including</div>
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<div class="">· a cover letter</div>
<div class="">· a research statement about previous and current research experience (1-page max., 12 pt)</div>
<div class="">· a CV</div>
<div class="">· the name and email address of two providers of letters of reference (no letter initially required)</div>
<div class="">· copies of relevant certificates and grades, and transcripts of records</div>
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<div class="">to Prof. Dr. Martin Fertl (<a href="mailto:jobs-agfertl@uni-mainz.de" class="">jobs-agfertl@uni-mainz.de</a>) (electronic application materials only). Review of the received application will start after November 30th, 2022, but the position will
remain open until filled. Please do not hesitate to contact Prof. Dr. Martin Fertl in case of any questions.</div>
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Prof. Dr. Martin Fertl (pronouns: he/him/his)<br class="">
Johannes Gutenberg University Mainz<br class="">
Institute of Physics<br class="">
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Staudingerweg 7<br class="">
55128 Mainz, Germany<br class="">
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Office: 02-627<br class="">
Phone: +49 6131 39-37687<br class="">
<a href="mailto:mfertl@uni-mainz.de" class="">Email: mfertl@uni-mainz.de</a> <br class="">
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