Search results for "Charged current"
showing 10 items of 139 documents
The coherent weak charge of matter
2017
We study the long-range force arising between two aggregates of ordinary matter due to a neutrino-pair exchange, in the limit of zero neutrino mass. Even if matter is neutral of electric charge, it is charged for this weak force. The interaction is described in terms of a coherent charge, which we call the weak flavor charge of aggregated matter. For each one of the interacting aggregates, this charge depends on the neutrino flavor as $Q_W^{\nu_e} = 2Z-N$, $Q_W^{\nu_\mu} = Q_W^{\nu_\tau} = -N$, where $Z$ is the number of protons and $N$ the number of neutrons. $Q_W^{\nu_e}$ depends explicitly on $Z$ because of the charged current contribution to $\nu_e e$ elastic scattering, while the $N$ t…
Nuclear medium effects in structure functions
2012
We discuss the nuclear-medium effects in the weak structure functions F2(x,Q2) and F3,(x,Q2) in the charged current neutrino and antineutrino induced deep inelastic reactions in some nuclei which are being used in the present or proposed neutrino oscillation experiments. Our study of the medium effects has been done using relativistic nuclear spectral functions which incorporates Fermi motion, binding energy and nucleon correlations. We also consider the pion and rho meson cloud contributions calculated from a microscopic model for meson-nucleus self-energies. Using these structure functions, the results for the differential cross section have been obtained and compared with some of the ava…
Leptonic CP violation with massless neutrinos
1989
Abstract Leptonic CP violation may arise in the SU(2) ⊗ U(1) theory even if the neutrinos are strictly massless and, as a result, it is potentially large. Theoretical scenarios include isosinglet neutral heavy leptons which are present in many extensions of the standard electroweak theory such as superstring inspired models. We discuss in detail the nature of this CP violation and show that it can occur in a two-generation model. Possible effects are briefly discussed.
Journal of High Energy Physics
2015
In this article we consider the presence of neutrino non-standard interactions (NSI) in the production and detection processes of reactor antineutrinos at the Daya Bay experiment. We report for the first time, the new constraints on the flavor non-universal and flavor universal charged-current NSI parameters, estimated using the currently released 621 days of Daya Bay data. New limits are placed assuming that the new physics effects are just inverse of each other in the production and detection processes. With this special choice of the NSI parameters, we observe a shift in the oscillation amplitude without distorting the $L/E$ pattern of the oscillation probability. This shift in the depth…
Measurement of the polarization in νμ charged current interactions in the NOMAD experiment
2001
The Λ polarization in νμ charged current interactions has been measured in the NOMAD experiment. The event sample (8087 reconstructed Λ 's) is more than an order of magnitude larger than that of previous bubble chamber experiments, while the quality of event reconstruction is comparable. We observe negative polarization along the W -boson direction which is enhanced in the target fragmentation region: Px(xF 0)=−0.09±0.06(stat)±0.03(sys) . These results provide a test of different models describing the nucleon spin composition and the spin transfer mechanisms. A significant transverse polarization (in the direction orthogonal to the Λ production plane) has been observed for the first time in…
Neutrino electron scattering and electroweak gauge structure: Future tests
1997
Low-energy high-resolution neutrino-electron scattering experiments may play an important role in testing the gauge structure of the electroweak interaction. We propose the use of radioactive neutrino sources (e.g. $^{51}$Cr) in underground experiments such as BOREXINO, HELLAZ and LAMA. As an illustration, we display the sensitivity of these detectors in testing the possible existence of extra neutral gauge bosons, both in the framework of E_6 models and of models with left-right symmetry.
Optimal β-beam at the CERN-SPS
2005
A β-beam with maximum (for 6He ions) or (for 18Ne) could be achieved at the CERN-SPS. We study the sensitivity to and δ of such a beam as function of γ, optimizing with the baseline constrained to CERN–Frejus (130 km), and also with simultaneous variation of the baseline, for a fixed ion flux. These results are compared to the standard scenario previously considered, with lower , and also with a higher option that requires a more powerful accelerator. We conclude that the sensitivity to CP violation and increases significantly with γ if the baseline is increased proportionally, while for the CERN–Frejus scenario the dependence on γ is mild provided γ is above 100.
A $B_4C$-silicon target for the detection of neutrino interactions
1998
This note describes the construction of a target for neutrino interactions composed of passive boron carbide plates interleaved with silicon microstrip detectors. The target contains four layers of passive material with a total mass of 45 kg and 600 single--sided silicon microstrip detectors with a total surface of 1.14 m$^2$ distributed over five layers. It is installed in the NOMAD spectrometer at the CERN SPS neutrino beam. During the 1997 run about 8000 \nm\ charged current interactions were estimated to have occurred in the target. For these events it will be possible to perform a precise measurement of both vertex and kinematical variables. This will provide invaluable experience towa…
RECENT RESULTS FROM AMANDA
2001
We present results based on data taken in 1997 with the 302-PMT Antarctic Muon and Neutrino Detector Array-B10 ("AMANDA-B10") array. Atmospheric neutrinos created in the northern hemisphere are observed indirectly through their charged current interactions which produce relativistic, Cherenkov-light-emitting upgoing muons in the South Pole ice cap. The reconstructed angular distribution of these events is in good agreement with expectation and demonstrates the viability of this ice-based device as a neutrino telescope.
Charged current weak production of the Delta resonance
1999
The charge changing weak production of Delta in nucleons and nuclei is studied. The reactions e^{-} p -> Delta^{0} ��_{e} and e^{+} p -> Delta^{++} \bar��_{e} are considered as a possible source of information about the weak N-Delta transition form factors. The low q^2 BNL data on neutrino production of Delta are used to extract the axial vector N-Delta coupling, taking into account the deuteron structure and the Delta width. Finally, pion production induced by neutrinos in ^{16}O in the Delta region, relevant to atmospheric neutrino experiments, is investigated.