Cloud evolution for various metallicities is investigated by three-dimensional nested grid simulations, in which the initial ratio of rotational to gravitational energy of the host cloud β0 (= 10 –10) and cloud metallicity Z (= 0–Z⊙) are parameters. Starting from a central number density of nc = 10 4 cm, cloud evolution for 48 models is calculated until the protostar is formed (nc ≃ 10 23 cm) o...

Stochastic density functional theory (sDFT) is becoming a valuable tool for studying ground-state properties of extended materials. The computational complexity describing the Kohn–Sham orbitals replaced by introducing set random (stochastic) leading to linear and often sub-linear scaling certain observables at account statistical error. Schemes reduce noise are essential, example, determining ...

We calculate fragmentation functions for a b-quark to fragment into color-singlet P-wave bound states c̄b in the Heavy Quark Effective Theory with the exact account of O(1/mb) corrections. We demonstrate an agreement of the obtained results with the corresponding calculations carried out in quantum chromodynamics. Introduction. The study of heavy quarkonia properties is a subject of much current...

We report on a previously unknown reaction mechanism involving water in the fragmentation reaction following chemical ionization. This result stems from a study presented here on the humidity-dependent and energy-dependent endoergic fragmentation of allyl methyl sulfide (AMS) upon protonation in a proton transfer reaction-mass spectrometer (PTR-MS). The fragmentation pathways were studied with ...

The ambipolar-diffusion theory of star formation predicts the formation of fragments in molecular clouds with mass-to-flux ratios greater than that of the parent-cloud envelope. By contrast, scenarios of turbulence-induced fragmentation do not yield such a robust prediction. Based on this property, Crutcher et al. (2009) proposed an observational test that could potentially discriminate between...