Nuclear Reaction Network for Primordial Nucleosynthesis: a detailed analysis of rates, uncertainties and light nuclei yields

We analyze in details the standard Primordial Nucleosynthesis scenario. In particular we discuss the key theoretical issues which are involved in a detailed prediction of light nuclide abundances, as the weak reaction rates, neutrino decoupling and nuclear rate modeling. We also perform a new analysis of available data on the main nuclear processes entering the nucleosynthesis reaction network, with particular stress on their uncertainties as well as on their role in determining the corresponding uncertainties on light nuclide theoretical estimates. The current status of theoretical versus experimental results for 2H, 3He, 4He and 7Li is then discussed using the determination of the baryon density as obtained from Cosmic Microwave Background anisotropies.Comment: LaTeX, 83 pages, 30 .pdf figures. Some typos in the units of R-functions in appendix D and relative plots fixe

The Effectiveness of Family Constellation Therapy in Improving Mental Health:A Systematic ReviewPalabras clave(sic)(sic)(sic)

Family/systemic constellation therapy is a short-term group intervention aiming to help clients better understand and then change their conflictive experiences within a social system (e.g., family). The aim of the present systematic review was to synthetize the empirical evidence on the tolerability and effectiveness of this intervention in improving mental health. The PsycINFO, Embase, MEDLINE, ISI Web of Science, Psyndex, PsycEXTRA, ProQuest Dissertations & Theses, The Cochrane Library, Google Scholar, and an intervention-specific organization's databases were searched for quantitative, prospective studies published in English, German, Spanish, French, Dutch or Hungarian up until April 2020. Out of 4,197 identified records, 67 were assessed for eligibility, with 12 studies fulfilling inclusion criteria (10 independent samples; altogether 568 participants). Outcome variables were diverse ranging from positive self-image through psychopathology to perceived quality of family relationships. Out of the 12 studies, nine showed statistically significant improvement postintervention. The studies showing no significant treatment benefit were of lower methodological quality. The random-effect meta-analysis-conducted on five studies in relation to general psychopathology-indicated a moderate effect (Hedges' g of 0.531, CI: 0.387-0.676). Authors of seven studies also investigated potential iatrogenic effects and four studies reported minor or moderate negative effects in a small proportion (5-8%) of participants that potentially could have been linked to the intervention. The data accumulated to date point into the direction that family constellation therapy is an effective intervention with significant mental health benefits in the general population; however, the quantity and overall quality of the evidence is low

Nuclear Reaction Rates and Primordial 6^6Li

We examine the possibility that Big Bang Nucleosynthesis (BBN) may produce non-trivial amounts of $^6$Li. If a primordial component of this isotope could be observed, it would provide a new fundamental test of Big-Bang cosmology, as well as new constraints on the baryon density of the universe. At present, however, theoretical predictions of the primordial $^6$Li abundance are extremely uncertain due to difficulties in both theoretical estimates and experimental determinations of the deuterium-plus-alpha radiative capture reaction cross-section. We also argue that present observational capabilities do not yet allow the detection of primeval $^6$Li in very metal-poor stars of the galactic halo. However, if the critical cross section is towards the upper end of its plausible range, then improvements in $^6$Li detection capabilities may allow the establishment of $^6$Li as another product of BBN. It is also noted that a primordial $^6$Li detection could help resolve current concerns about the extragalactic D/H determination.Comment: 10 pages, REVTeX, 5 PostScript figures with psfig. Submitted to Physical Review

Updated Nucleosynthesis Constraints on Unstable Relic Particles

We revisit the upper limits on the abundance of unstable massive relic particles provided by the success of Big-Bang Nucleosynthesis calculations. We use the cosmic microwave background data to constrain the baryon-to-photon ratio, and incorporate an extensively updated compilation of cross sections into a new calculation of the network of reactions induced by electromagnetic showers that create and destroy the light elements deuterium, he3, he4, li6 and li7. We derive analytic approximations that complement and check the full numerical calculations. Considerations of the abundances of he4 and li6 exclude exceptional regions of parameter space that would otherwise have been permitted by deuterium alone. We illustrate our results by applying them to massive gravitinos. If they weigh ~100 GeV, their primordial abundance should have been below about 10^{-13} of the total entropy. This would imply an upper limit on the reheating temperature of a few times 10^7 GeV, which could be a potential difficulty for some models of inflation. We discuss possible ways of evading this problem.Comment: 40 pages LaTeX, 18 eps figure