Influence of epithermal muonic molecule formation on kinetics of the μ\muCF processes in deuterium

The non-resonant formation of $dd\mu$ molecules in the loosely bound state in collisions of non-thermalized $d\mu$ atoms with deuterium molecules D$_2$ has been considered. The process of such a type is possible only for collision energies exceeded the ionization potential of D$_2$. The calculated rates of $dd\mu$ formation in the above-threshold energy region are about one order of magnitude higher than obtained earlier. The role of epithermal non-resonant $\mu$-molecule formation for the kinetics of $\mu$CF processes in D$_2$ gas was studied. It was shown that the non-resonant $dd\mu$ formation by $d\mu$ atoms accelerated during the cascade can be directly observed in the neutron time spectra at very short initial times.Comment: 6 pages, 5 figures, Proceedings of the International Conference on Exotic Atoms and Related Topics EXA-2011, Vienna, Sep 5-9, 201

Prospects for Creation of Cardioprotective and Antiarrhythmic Drugs Based on Opioid Receptor Agonists

It has now been demonstrated that the μ, δ(1), δ(2), and κ(1) opioid receptor (OR) agonists represent the most promising group of opioids for the creation of drugs enhancing cardiac tolerance to the detrimental effects of ischemia/reperfusion (I/R). Opioids are able to prevent necrosis and apoptosis of cardiomyocytes during I/R and improve cardiac contractility in the reperfusion period. The OR agonists exert an infarct‐reducing effect with prophylactic administration and prevent reperfusion‐induced cardiomyocyte death when ischemic injury of heart has already occurred; that is, opioids can mimic preconditioning and postconditioning phenomena. Furthermore, opioids are also effective in preventing ischemia‐induced arrhythmias

High-precision spectroscopy of the HD+ molecule at the 1-p.p.b. level

Recently we reported a high-precision optical frequency measurement of the (v, L): (0, 2)→ (8, 3) vibrational overtone transition in trapped deuterated molecular hydrogen (HD+) ions at 10 mK temperature. Achieving a resolution of 0.85 parts-per-billion (p.p.b.), we found the experimental value [ν0 = 383, 407, 177.38 (41) MHz] to be in agreement with the value from molecular theory [νth 383, 407, 177.150 (15) MHz] within 0.6 (1.1) p.p.b. (Biesheuvel et al. in Nat Commun 7:10385, 2016). This enabled an improved test of molecular theory (including QED), new constraints on the size of possible effects due to ‘new physics,’ and the first determination of the proton–electron mass ratio from a molecule. Here, we provide the details of the experimental procedure, spectral analysis, and the assessment of systematic frequency shifts. Our analysis focuses in particular on deviations of the HD+ velocity distribution from thermal (Gaussian) distributions under the influence of collisions with fast ions produced during (laser-induced) chemical reactions, as such deviations turn out to significantly shift the hyperfine-less vibrational frequency as inferred from the saturated and Doppler-broadened spectrum, which contains partly unresolved hyperfine structure