相关论文: Improved Determination of the Neutron Lifetime
We report a new measurement of the neutron decay lifetime by the absolute counting of in-beam neutrons and their decay protons. Protons were confined in a quasi-Penning trap and counted with a silicon detector. The neutron beam fluence was…
A measurement of the neutron lifetime $\tau_{n}$ performed by the absolute counting of in-beam neutrons and their decay protons has been completed. Protons confined in a quasi-Penning trap were accelerated onto a silicon detector held at a…
The neutron lifetime is determined for now most accurately by two methods --the so-called "beam method" and the method of neutron storage in a trap. The goal of this research is to obtain the neutron lifetime with a higher precision by…
The analysis of experiments on measuring neutron lifetime has been made. The latest most accurate result of measuring neutron lifetime [Phys. Lett. B 605, 72 (2005)] 878.5 \pm 0.8 s differs from the world average value [Phys. Lett. B 667, 1…
This article proposes a new method to measure the proton detector efficiency for use in "beam" determinations of the free neutron lifetime. There is currently a 4{\sigma} disagreement between the "beam" and "storage" methods of measuring…
The precise value of the mean neutron lifetime, $\tau_n$, plays an important role in nuclear and particle physics and cosmology. It is a key input for predicting the ratio of protons to helium atoms in the primordial universe and is used to…
The neutron lifetime, $\tau$ = 880.2 $\pm$ 1.0 sec , is an important parameter for particle physics and cosmology. There is, however, an 8.4 sec (4.0$\,\sigma$) deviation between the measured value of the neutron lifetime using two methods…
The puzzle remains in the large discrepancy between neutron lifetime measured by the two distinct experimental approaches -- counts of beta decays in a neutron beam and storage of ultracold neutrons in a potential trap, namely, the beam…
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.…
A neutron decays into a proton, an electron, and an anti-neutrino through the beta-decay process. The decay lifetime ($\sim$880 s) is an important parameter in the weak interaction. For example, the neutron lifetime is a parameter used to…
The recent measurement of the lifetime of the free neutron using the beam method has an 8.7 s (4$\sigma$) discrepancy with UCN measurements. The goal of the BL3 experiment is to improve the statistical error of this measurement and help…
The neutron lifetime is important in understanding the production of light nuclei in the first minutes after the big bang and it provides basic information on the charged weak current of the standard model of particle physics. Two different…
The ``neutron lifetime puzzle'' arises from the discrepancy between neutron lifetime measurements obtained using the beam method, which measures decay products, and the bottle method, which measures the disappearance of neutrons. To resolve…
We report a new measurement of the neutron lifetime using ultra-cold neutrons stored in a magneto-gravitational trap made of permanent magnets. Neutrons surviving in the trap after fixed storage times have been counted and the trap losses…
We report an improved measurement of the free neutron lifetime $\tau_{n}$ using the UCN$\tau$ apparatus at the Los Alamos Neutron Science Center. We counted a total of approximately $38\times10^{6}$ surviving ultracold neutrons (UCN) after…
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…
The review of experimental measurements of neutron lifetime is presented. Latest measurements with gravitational trap (PNPI NRC KI) and magnetic trap (LANL, USA) confirmed the result obtained by PNPI group in 2005. The results of…
The neutron beta-decay lifetime plays an important role both in understanding weak interactions within the framework of the Standard Model and in theoretical predictions of the primordial abundance of 4He in Big Bang Nucleosynthesis. In…
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…
We present the status of current US experimental efforts to measure the lifetime of the free neutron by the "beam" and "bottle" methods. BBN nucleosynthesis models require accurate measurements with 1 second uncertainties, which are…