In this paper, we analyze the scattering of the neutrino beam on the polarized electron target, and predict the effects of two theoretically possible scenarios beyond the Standard Model. In both scenarios, Dirac neutrinos are assumed to be massive.First, we consider how the existence of CP violation phase between the complex vector V and axial A couplings of the Left-handed neutrinos affects the azimuthal dependence of the differential cross section. This asymmetry does not vanish in the massless neutrino limit. The azimuthal angle φ e ′ of outgoing electron momentum is measured with respect to the transverse component of the initial electron polarization η ⊥ e . We indicate the possibility of using the polarized electron target to measure the CP violation in the νµe − scattering. The future superbeam and neutrino factory experiments will provide the unique opportunity for the leptonic CP violation studies, if the large magnetized sampling calorimeters with good event reconstruction capabilities are build.Next, we take into account a scenario with the participation of the exotic scalar S coupling of the Right-handed neutrinos in addition to the standard vector V and axial A couplings of the Lefthanded neutrinos. The main goal is to show how the presence of the R-handed neutrinos, in the above process changes the spectrum of recoil electrons in relation to the expected Standard Model prediction, using the current limits on the non-standard couplings. The interference terms between the standard and exotic couplings in the differential cross section depend on the angle α between the transverse incoming neutrino polarization and the transverse electron polarization of the target, and do not vanish in the limit of massless neutrino. The detection of the dependence on this angle in the energy spectrum of recoil electrons would be a signature of the presence of the R-handed neutrinos in the neutrino-electron scattering. To make this test feasible, the polarized artificial neutrino source needs to be identified.

In this paper, we analyze the scattering of solar neutrinos on the polarized electron target, and predict how the effect of parity violation in weak interactions may help to distinguish neutrino signal from detector background. We indicate that the knowledge of the Sun motion across the sky is sufficient to predict the day/night asymmetry in the $(\nu_ee^-)$ scattering on the polarized electron target. To make this detection feasible, the polarized electron target for solar neutrinos needs to be build from magnetic materials, e.g. from ferromagnetic iron foils, paramagnetic scintillator crystals or scintillating ferrofluids.Comment: 3 pages, 2 eps figures, revte

In this paper a scenario with the participation of the exotic scalar S, tensor T and pseudoscalar P couplings of the right-handed neutrinos in addition to the standard vector V, axial A couplings of the left-handed neutrinos in the low-energy (νµe − ) and (νee − ) scattering processes is considered. Neutrinos are assumed to be massive Dirac fermions and to be polarized. Both reactions are studied at the level of the fourfermion point interaction. The main goal is to show that the physical consequence of the presence of the right-handed neutrinos is an appearance of the azimuthal asymmetry in the angular distribution of the recoil electrons caused by the non-vanishing interference terms between the standard and exotic couplings, proportional to the transverse neutrino polarization vector. The upper limits on the expected effect of this asymmetry for the low-energy neutrinos (Eν < 1 M eV ) are found. We also show that if the neutrino helicity rotation (νL → νR) in the solar magnetic field takes place, the similar effect of the azimuthal asymmetry of the recoil electrons scattered by the solar neutrinos should be observed. This effect would also come from the interference terms between the standard (V, A)L and exotic (S, T, P )R couplings. New-type neutrino detectors with good angular resolution could search for the azimuthal asymmetry in event number. PACS: 13.15.+g, 13.88.+e

In this paper, we indicate a possibility of utilizing the intense chromium source (∼370 PBq) in probing the neutrino nature in low energy neutrino experiments with the ultra-low threshold and background real-time Borexino detector located near the source (∼8 m). We analyse the elastic scattering of electron neutrinos (Dirac or Majorana, respectively) on the unpolarised electrons in the relativistic neutrino limit. We assume that the incoming neutrino beam is the superposition of left-right chiral states produced by the chromium source. Left chiral neutrinos may be detected by the standard V − A and non-standard scalar S L , pseudoscalar P L , tensor T L interactions, while right chiral ones partake only in the exotic V + A and S R , P R , T R interactions. Our model-independent study is carried out for the flavour (current) neutrino eigenstates. We compute the expected event number for the standard V − A interaction of the left chiral neutrinos using the current experimental values of standard couplings and in the case of left-right chiral superposition. We show that the significant decrement in the event number due to the interference terms between the standard and exotic interactions for the Majorana neutrinos may appear. We also demonstrate how the presence of the exotic couplings affects the energy spectrum of outgoing electrons, both for the Dirac and Majorana cases. The 90 % C.L. sensitivity contours in the planes of corresponding exotic couplings are found. The presence of interferences in the Majorana case gives the stronger constraints than for the Dirac neutrinos, even if the neutrino source is placed outside the detector.

In this paper, we indicate a possibility of utilizing the elastic scattering of the Dirac low energy (∼ 1 MeV) electron neutrinos (ν e 's) on the polarized electron target (PET) in testing the time reversal symmetry violation (TRSV). We consider a scenario in which the incoming ν e beam is the superposition of left chiral (LC) and right chiral (RC) states. LC ν e 's interact mainly by the standard V − A and small admixture of non-standard scalar S L , pseudoscalar P L , tensor T L interactions, while RC ones are only detected by the exotic V + A and S R , P R , T R interactions. In addition, one assumes that the spin polarization vector of the initial ν e 's is turned aside from its momentum, and due to this the nonvanishing transversal component of the ν e spin polarization appears. We compute the differential cross section as a function of the recoil electron azimuthal angle and scattered electron energy, and show how the interference terms between standard V − A and exotic S R , P R , T R couplings depend on the various angular correlations among the transversal ν e spin polarization, the polarization of the electron target, the incoming neutrino momentum and the outgoing electron momentum in the limit of relativistic ν e . We illustrate how the maximal value of recoil electrons azimuthal asymmetry and the asymmetry axis location of outgoing electrons depend on the azimuthal angle of the transversal component of the ν e spin polarization, both for the time reversal symmetry conservation (TRSC) and TRSV. Next, we display that the electron energy spectrum and polar angle distribution of the recoil electrons are also sensitive to the interference terms between V − A and S R , P R , T R couplings, proportional to the T-even and T-odd angular correlations among the transversal ν e polarization, the electron polarization of the target, and the incoming ν e momentum, respectively. Our modelindependent analysis is carried out for the flavor ν e 's. To a make such tests feasible, the intense (polarized) artificial ν e source, PET and the appropriate detector measuring the directionality of the outgoing electrons, and/or the recoil electrons energy with a high resolution have to be identified.