On the Free Neutron Decay with Neutrino(s) Interactions

This paper proposes a mechanism for the decay of free neutron with interactions with neutrino(s). A mathematical framework is developed using canonical ensemble framework for the interactions. Probability distribution of neutron discrete energy states has been derived which is a function of neutrino-zeta – a macroscopic property of neutrinos. Consequently, a relationship between neutron decay constant and probability of neutron beta decay is provided, assuming linear proportionality. Furthermore, qualitative explanation of neutron lifetime puzzle, where discrepancy in lifetime measurements based on measurement method (Bottle vs Beam), is related to neutrino microscopic cross-sections. In addition, inverse beta-decay reaction of proton and beta-negative and beta-positive reaction of radionuclides have been analyzed using the proposed mechanism. The probabilities of beta-negative and beta-positive reactions in nature are qualitatively in agreement with the proposed mechanism. Lastly, way to test the mechanism experimentally with reactor neutrinos and neutrino beams has been presented.

A new angle on an old problem: helicity approach to neutron beta decay in the Standard Model

We elaborate on the dichotomy between the description of the semileptonic decays of heavy hadrons on the one hand and the semileptonic decays of light hadrons such as neutron $$\beta $$β decays on the other hand. For example, almost without exception the semileptonic decays of heavy baryons are described in cascade fashion as a sequence of two two-body decays $$B_1 \rightarrow B_2 + W_\mathrm{off-shell}$$B1→B2+Woff-shell and $$W_{\mathrm{off-shell}} \rightarrow \ell + \nu _\ell $$Woff-shell→ℓ+νℓ whereas neutron $$\beta $$β decays are analyzed as true three-body decays $$n \rightarrow p + e^- +{\bar{\nu }}_e$$n→p+e-+ν¯e. Within the cascade approach it is possible to define a set of seven angular observables for polarized neutron $$\beta $$β decays as well as the longitudinal, transverse and normal polarization of the decay electron. We determine the dependence of the observables on the usual vector and axial vector form factors. In order to be able to assess the importance of recoil corrections we expand the rate and the $$q^2$$q2 averages of the observables up to NLO and NNLO in the recoil parameter $$\delta =(M_n-M_p)/(M_n+M_p)= 0.689\cdot 10^{-3}$$δ=(Mn-Mp)/(Mn+Mp)=0.689·10-3. Remarkably, we find that the rate and three of the four parity conserving polarization observables that we analyze are protected from NLO recoil corrections when the second class current contributions are set to zero.

aCORN: Measuring the electron-antineutrino correlation in neutron beta decay

The aCORN experiment uses a novel asymmetry method to measure the electron-antineutrino correlation (a-coefficient) in free neutron decay that does not require precision proton spectroscopy. aCORN completed two physics runs at the NIST Center for Neutron Research. The first run on the NG-6 beam line obtained the result a = 0.1090 +/- 0.0030 (stat) +/- 0.0028 (sys), the most precise to date. The second run on the new NG-C high flux beam line promises an improvement in precision to ¡ 2%. In addition we show that an improved measurement of the neutrino asymmetry (B-coefficient) can be made using the aCORN apparatus on a highly polarized neutron beam.