18 research outputs found
Supernova neutrino three-flavor evolution with dominant collective effects
Neutrino and antineutrino fluxes from a core-collapse galactic supernova are
studied, within a representative three-flavor scenario with inverted mass
hierarchy and tiny 1-3 mixing. The initial flavor evolution is dominated by
collective self-interaction effects, which are computed in a full three-family
framework along an averaged radial trajectory. During the whole time span
considered (t=1-20 s), neutrino and antineutrino spectral splits emerge as
dominant features in the energy domain for the final, observable fluxes. Some
minor or unobservable three-family features (e.g., related to the
muonic-tauonic flavor sector) are also discussed for completeness. The main
results can be useful for SN event rate simulations in specific detectors.Comment: 22 pages, including 9 figures (1 section with 3 figures added).
Accepted for publication in JCA
Fatigue Crack Growth Mechanisms At the Microstructure Scale in Al-Si-Mg Cast Alloys: Mechanisms in Regions II and III
The fatigue crack growth behavior in Regions 11 and III of crack growth was investigated for hypoeutectic and eutectic Al-Si-Mg cast alloys. To isolate and establish the mechanistic contributions of characteristic microstructural features (dendritic α-Al matrix, eutectic phases, Mg-Si strengthening precipitates), alloys with various Si content/morphology, grain size level, and matrix strength were studied; the effect of secondary dendrite arm spacing (SDAS) was also assessed. In Regions 11 and III of crack growth, the observed changes in the fracture surface appearance were associated with changes in crack growth mechanisms at the microstructural scale (from a linear advance predominantly through primary α-Al to a tortuous advance exclusively through AI-Si eutectic Regions). The extent of the plastic zone ahead of the crack tip was successfully used to explain the changes in growth mechanisms. The fatigue crack growth tests were conducted on compact tension specimens under constant stress ratio, R = 0.1, in ambient conditions
Measurement of the CP-violating phase in decays and limits on penguin effects
Time-dependent CP violation is measured in the channel for each resonant final state using data
collected with an integrated luminosity of 3.0 fb in collisions
using the LHCb detector. The final state with the largest rate,
, is used to measure the CP-violating angle to be . This result can be used to
limit the size of penguin amplitude contributions to CP violation measurements
in, for example, decays. Assuming approximate
SU(3) flavour symmetry and neglecting higher order diagrams, the shift in the
CP-violating phase is limited to be within the interval
[, +] at 95% confidence level. Changes to the limit
due to SU(3) symmetry breaking effects are also discussed.Comment: 18 pages, 6 figures; v2-updated from reviewers comments and added a
figur