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Spectroscopy, Quantum Dynamics and Electroweak Parity Violation in Chiral Molecules


The PI and his group have in theoretical and preparatory experimental efforts approached one of the most fundamental questions of molecular physics, concerning the role of parity violation in chiral molecules, with consequences for physical stereochemistry. The traditional point of view assigns exactly equal ground state energies to the enantiomers of chiral molecules. However, with the discovery of parity violation in physics we expect a small “parity violating” energy difference D, corresponding to an in principle measurable reaction enthalpy. Because D is expected typically in the subfemto eV range these energies were in the past considered to be immeasurably small. Recent theoretical and experimental progress initiated by our group has led to order of magnitude larger predicted values for D and has also made rovibrational line assignment of optical spectra of chiral molecules possible (Quack, Stohner, Willeke, Ann. Revs. Phys. Chem. 2008). Thus the outlook to carry out successful experiments on D is now good, following a scheme previously published by us. The present proposal describes in detail several logical steps for these experiments.
1. Theoretical analysis and high resolution spectroscopy of selected chiral molecules.
2. Quantum tunneling dynamics from spectroscopy to identify appropriate quantum states for the experiment.
3. Preparation of superposition states of otherwise stable R and S enantiomer quantum levels to generate “parity isomer” states (never before prepared)
4. Spectroscopic observation of the time dependent change of the parity isomer spectra resulting in a first determination of the parity violating D in chiral molecules.
We also discuss the feasibility and the outlook to gain fundamentally new knowledge.

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Raemistrasse 101
8092 Zuerich

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Schweiz/Suisse/Svizzera Zürich Zürich
Activity type
Higher or Secondary Education Establishments
Administrative Contact
Martin Paul Werner Quack (Prof.)
Principal investigator
Martin Paul Werner Quack (Prof.)
EU contribution
No data

Beneficiaries (1)