A New World Average Value for the Neutron Lifetime

The analysis of the data on measurements of the neutron lifetime is presented. A new most accurate result of the measurement of neutron lifetime [Phys. Lett. B 605 (2005) 72] 878.5 +/- 0.8 s differs from the world average value [Phys. Lett. B 667 (2008) 1] 885.7 +/- 0.8 s by 6.5 standard deviations. In this connection the analysis and Monte Carlo simulation of experiments [Phys. Lett. B 483 (2000) 15] and [Phys. Rev. Lett. 63 (1989) 593] is carried out. Systematic errors of about -6 s are found in each of the experiments. The summary table for the neutron lifetime measurements after corrections and additions is given. A new world average value for the neutron lifetime 879.9 +/- 0.9 s is presented.Comment: 27 pages, 13 figures; Fig.13 update

Measurement of the neutron lifetime using a gravitational trap and a low-temperature Fomblin coating

We present a new value for the neutron lifetime of 878.5 +- 0.7 stat. +- 0.3 syst. This result differs from the world average value (885.7 +- 0.8 s) by 6.5 standard deviations and by 5.6 standard deviations from the previous most precise result. However, this new value for the neutron lifetime together with a beta-asymmetry in neutron decay, Ao, of -0.1189(7) is in a good agreement with the Standard Model.Comment: 11 pages, 9 figures; extended content with some correction

Nanoparticles as a possible moderator for an ultracold neutron source

Ultracold and very cold neutrons (UCN and VCN) interact strongly with nanoparticles due to the similarity of their wavelengths and nanoparticles sizes. We analyze the hypothesis that this interaction can provide efficient cooling of neutrons by ultracold nanoparticles at certain experimental conditions, thus increasing the density of UCN by many orders of magnitude. The present analytical and numerical description of the problem is limited to the model of independent nanoparticles at zero temperature. Constraints of application of this model are discussed

Neutron lifetime measurements using gravitationally trapped ultracold neutrons

Our experiment using gravitationally trapped ultracold neutrons (UCN) to measure the neutron lifetime is reviewed. Ultracold neutrons were trapped in a material bottle covered with perfluoropolyether. The neutron lifetime was deduced from comparison of UCN losses in the traps with different surface-to-volume ratios. The precise value of the neutron lifetime is of fundamental importance to particle physics and cosmology. In this experiment, the UCN storage time is brought closer to the neutron lifetime than in any experiments before:the probability of UCN losses from the trap was only 1% of that for neutron beta decay. The neutron lifetime obtained,878.5+/-0.7stat+/-0.3sys s, is the most accurate experimental measurement to date.Comment: 38 pages, 19 figures,changed conten

Options for the Neutron Lifetime Measurements in Traps

Different geometries for the neutron lifetime measurements by the method of ultracold neutron storage in material traps and additional possibilities for the neutron storage in the magnetic storage ring are considered.Comment: 21 p., 11 figure

Цитокины и оксид азота при бронхиальной астме

Complex interactions between nitric oxide and cytokines of atopic inflammation are presented. The effects of interleukin-4 on nitric oxide synthesis, immunoregulatory properties of nitric oxide and its influence on Th1/Th2 balance are described.Представлены современные данные о системе взаимосвязи ключевых цитокинов, регулирующих атопическое воспаление при бронхиальной астме, и оксида азота. Описаны эффекты интерлейкина-4 на синтез оксида азота. Приведены данные о влиянии оксида азота на синтез цитокинов и баланс Th1/Th2, нарушение которого лежит в основе реагинового иммунного ответа