Estimates of weak and electromagnetic nuclear decay signatures for neutrino reactions in Super-Kamiokande

We estimate possible delayed β decay signatures of the neutrino induced reactions on 16O in a two-step model: the primary neutrino (ν,l) process, where l is the lepton in the final state, is described within the random phase approximation, while the subsequent decay of the excited nuclear state in the final channel is treated within the statistical model. We calculate partial reaction cross sections leading to β unstable nuclei. We consider neutrino energies up to 500 MeV, relevant for atmospheric neutrino detection in Super-Kamiokande, and supernova neutrino spectra

Weak reactions on 12C within the Continuum Random Phase Approximation with partial occupancies

We extend our previous studies of the neutrino-induced reactions on 12C and muon capture to include partial occupation of nuclear subshells in the framework of the continuum random phase approximation. We find, in contrast to the work by Auerbach et al., that a partial occupation of the p1/2 subshell reduces the inclusive cross sections only slightly. The extended model describes the muon capture rate and the 12C(nu_e,e-)12N cross section very well. The recently updated flux and the improved model bring the calculated 12C(nu_mu,mu^-)12N cross section (~ 17.5 10^{-40} cm^2) and the data (12.4 +/- 0.3(stat.) +/- 1.8(syst.) 10^{-40} cm^2) closer together, but does not remove the discrepancy fully.Comment: 12 pages, 2 figure

Quasielastic neutrino scattering from oxygen and the atmospheric neutrino problem

We examine several phenomena beyond the scope of Fermi-gas models that affect the quasielastic scattering (from oxygen) of neutrinos in the 0.1 -- 3.0 GeV range. These include Coulomb interactions of outgoing protons and leptons, a realistic finite-volume mean field, and the residual nucleon-nucleon interaction. None of these effects are accurately represented in the Monte Carlo simulations used to predict event rates due to $\mu$ and $e$ neutrinos from cosmic-ray collisions in the atmosphere. We nevertheless conclude that the neglected physics cannot account for the anomalous $\mu$ to $e$ ratio observed at Kamiokande and IMB, and is unlikely to change absolute event rates by more than 10--15\%. We briefly mention other phenomena, still to be investigated in detail, that may produce larger changes.Comment: In Revtex version 2. 14 pages, 3 figures (available on request from J. Engel, tel. 302-831-4354, [email protected]

Neutrino–nucleus reactions and nuclear structure

The methods used in the evaluation of the neutrino–nucleus cross section are reviewed. Results are shown for a variety of targets of practical importance. Many of the described reactions are accessible in future experiments with neutrino sources from the pion and muon decays at rest, which might be available at the neutron spallation facilities. Detailed comparison between the experimental and theoretical results would establish benchmarks needed for verification and/or parameter adjustment of the nuclear models. Having a reliable tool for such calculation is of great importance in a variety of applications, e.g. the neutrino oscillation studies, detection of supernova neutrinos, description of the neutrino transport in supernovae and description of the r-process nucleosynthesis

Inclusive 12C(νμ,μ)12N reaction in the continuum random phase approximation

Motivated by a recent experiment at LAMPF we calculate cross sections for muon-neutrino and muon-antineutrino charged-current reactions on 12C within the continuum RPA model. We also determine the branching ratios for the main decay channels of these reactions by application of a statistical model

Neutrino induced transitions between the ground states of the A=12 triad

Neutrino induced reactions on $^{12}$C, an ingredient of liquid scintillators, have been studied in several experiments. We show that for currently available neutrino energies, $E_{\nu} \le$ 300 MeV, calculated exclusive cross sections $^{12}$C$_{gs}(\nu,l)$$^{12}$N$_{gs}$ for both muon and electron neutrinos are essentially model independent, provided the calculations simultaneously describe the rates of several other reactions involving the same states or their isobar analogs. The calculations agree well with the measured cross sections, which can be therefore used to check the normalization of the incident neutrino spectrum and the efficiency of the detector.Comment: 9 pages REVTEX, 2 postscript figures, text and figures available at http://www.krl.caltech.edu/preprints/MAP.htm

Can guided introspection help avoid rationalization of meat consumption? Mixed-methods results of a pilot experimental study

The need for reducing meat consumption in affluent countries is increasingly recognized as crucial to minimizing carbon footprint. However, confronting individuals with rational arguments can prompt emotional discomfort, which is often relieved by engaging in rationalization processes stabilizing current consumption patterns. Mindfulness research suggests that making people aware of their emotional reactions through introspection can reduce these rationalization processes. In this mixed-method pilot experimental study, we inquired whether a single guided introspection, inspired by the micro-phenomenological interview technique, can alter individuals' experience of and abilities to deal with cognitive dissonance. Furthermore, we asked if such an intervention can stimulate attitude or intention changes concerning meat consumption. After inducing cognitive dissonance by exposing participants to pictures of the slaughter of a cow, the intervention group (n = 36) participated in the guided introspection, while the control group (n = 39) played solitaire. Self-report questionnaire measures of emotional discomfort, rationalization strategies, and attitudes towards meat consumption were administered before and after the intervention. Also, open-ended responses to participants’ experience of the study were analyzed. Quantitative results show significantly lower negative attitudes toward reducing meat consumption in the intervention group compared to the control group (partial 2 = 0.107). Qualitative results indicate that these participants are more aware of negative emotions while engaging less in rationalization strategies. We conclude that our study indicates some potential for guided introspection to affect dissonance resolution and provide suggestions for future research

Muon capture on nuclei with N > Z, random phase approximation, and in-medium renormalization of the axial-vector coupling constant

We use the random phase approximation to describe the muon capture rate on ${}^{44}$Ca,${}^{48}$Ca, ${}^{56}$Fe, ${}^{90}$Zr, and ${}^{208}$Pb. With ${}^{40}$Ca as a test case, we show that the Continuum Random Phase Approximation (CRPA) and the standard RPA give essentially equivalent descriptions of the muon capture process. Using the standard RPA with the free nucleon weak form factors we reproduce the experimental total capture rates on these nuclei quite well. Confirming our previous CRPA result for the $N = Z$ nuclei, we find that the calculated rates would be significantly lower than the data if the in-medium quenching of the axial-vector coupling constant were employed.Comment: submitted to Phys. Rev.

Signal for supernova νμ\nu_\mu and ντ\nu_\tau neutrinos in water \v{C}erenkov detectors

We suggest that photons with energies between 5 and 10 MeV, generated by the ($\nu,\nu'p\gamma$) and ($\nu,\nu'n\gamma$) reactions on $^{16}$O, constitute a signal which allows a unique identification of supernova $\nu_\mu$ and $\nu_\tau$ neutrinos in water \v{C}erenkov detectors. We calculate the yield of such $\gamma$ events and estimate that a few hundred of them would be detected in Superkamiokande for a supernova at 10 kpc distance.Comment: 8 pages, RevTex 3.0, figures and text available at http://www.krl.caltech.edu/preprints/MAP.htm

Muon capture, continuum random phase approximation, and in-medium renormalization of the axial-vector coupling constant

We use the continuum random phase approximation to describe the muon capture on 12C,16O, and 40Ca. We reproduce the experimental total capture rates on these nuclei to better than 10% using the free nucleon weak form factors and two different residual interactions. However, the calculated rates for the same residual interactions are significantly lower than the data if the in-medium quenching of the axial-vector coupling constant is employed