0000000000174285
AUTHOR
Javier Segura
A potential test of the CP properties and Majorana nature of neutrinos
The scattering of solar neutrinos on electrons may reveal their CP properties, which are particularly sensitive to their Majorana nature. The cross section is sensitive to the neutrino dipole moments through an interference of electro-magnetic and weak amplitudes. We show how future solar neutrino experiments with good angular resolution and low energy threshold, such as Hellaz, can be sensitive to the resulting azimuthal asymmetries in event number, and could therefore provide valuable information on the CP properties and the nature of the neutrinos, provided the solar magnetic field direction is fixed.
A code to evaluate prolate and oblate spheroidal harmonics
Abstract We present a code to evaluate prolate ( P n m ( x ), Q n m ( x ); n ≥ m , x > 1) and oblate ( P n m ( ix ), Q n m ( ix ); n ≥ m , x > 0) spheroidal harmonics, that is, spherical harmonics ( n and m integers) for real arguments larger than one and for purely imaginary arguments. We start from the known values (in closed form) of P m m and P m +1 m and we apply the forward recurrence relation over n up to a given degree n = N Max . The Wronskian relating P 's and Q 's, together with the evaluation of the continued fraction for Q m+N staggeredMax m / Q m+N staggeredMax -1 m , allows the calculation of Q m+N staggeredMax m and Q m+N staggeredMax -1 m . Backward recurrence is then appli…
Nuclear tests for the strange charge from factor of the nucleon
Abstract It is shown that the measurements of elastic and inelastic scattering of neutrinos and parity-violating asymmetry of longitudinally polarized electrons on spin-isospin zero nuclei would yield model independent information about the strangeness charge form factor. Nunerical estimates of the contribution of this form factor are presented for 4 He, 12 C and 16 O nuclei in impulse approximation using strangeness vector from factors of the nucleon recently suggested in the literature. A general relation between the P -odd asymmetry in electron scattering and the cross sections of neutrino and unpolarized electron scattering on spin zero nuclei is obtained.
Evaluation of legendre functions of argument greater than one
Abstract In this paper we present an algorithm to evaluate Legendre functions of the first and second kinds ( P v , Q v ) for integraland half-integral order and argument greater than one. The code is based on the calculation of the continued fraction for the Q 's. the Wronskian relating P 's and Q 's and the application of forward recurrence relations for the P 's and backward recurrence for the Q 's. We also show an application of these algorithms to the evaluation of the electrostatic field due to a charged toroidal conductor at potential V .
Dynamical zeros in neutrino-electron elastic scattering at leading order
We show the existence of dynamical zeros in the helicity amplitudes for neutrino-electron elastic scattering at lowest order in the standard theory. In particular, the $\lambda=1/2$ non-flip electron helicity amplitude in the electron antineutrino process vanishes for an incident neutrino energy $E_{\nu}=m_{e}/(4sin^{2}\theta_{W})$ and forward electrons (maximum recoil energy). The rest of helicity amplitudes show kinematical zeros in this configuration and therefore the cross section vanishes. Prospects to search for neutrino magnetic moment are discussed.
A novel kind of neutrino oscillation experiment
A novel method to look for neutrino oscillations is proposed based on the elastic scattering process $\bar{\nu}_{i} e^{-}\rightarrow \bar{\nu}_{i} e^{-}$, taking advantage of the dynamical zero present in the differential cross section for $\bar{\nu}_{e} e^{-}\rightarrow \bar{\nu}_{e} e^{-}$. An effective tunable experiment between the "appearance" and "disappearance" limits is made possible. Prospects to exclude the allowed region for atmospheric neutrino oscillations are given.
Neutrino magnetic moments and low-energy solar neutrino-electron scattering experiments
The scattering of solar neutrinos on electrons is sensitive to the neutrino magnetic moments through an interference of electromagnetic and weak amplitudes in the cross section. We show that future low-energy solar neutrino experiments with good angular resolution can be sensitive to the resulting azimuthal asymmetries in event number and should provide useful information on non-standard neutrino properties such as magnetic moments. We compare asymmetries expected at HELLAZ (mainly pp neutrinos) with those at the Kamiokande and Super-Kamiokande experiments (Boron neutrinos), both for the case of Dirac and Majorana neutrinos and discuss the advantages of low energies. Potentially interesting…