Dispersive ππ→KK[over ¯] Amplitude and Giant CP Violation in B to Three Light-Meson Decays at LHCb.

The LHCb collaboration has recently reported the largest CP violation effect from a single amplitude, as well as other giant CP asymmetries in several B-meson decays into three charmless light mesons. It is also claimed that this is predominantly due to ππ→KK[over ¯] rescattering in the final state, particularly in the 1 to 1.5 GeV region. In these analyses the ππ→KK[over ¯] amplitude is by default estimated from the ππ elastic scattering amplitude and does not describe the existing ππ→KK[over ¯] scattering data. Here we show how the recent model-independent dispersive analysis of ππ→KK[over ¯] data can be easily implemented in the LHCb formalism. This leads to a more accurate description of the asymmetry, while being consistent with the measured scattering amplitude and confirming the prominent role of hadronic final state interactions, paving the way for more elaborated analyses.

Validation of electrodeposited 241Am alpha-particle sources for use in liquified gas detectors at cryogenic temperatures.

This paper describes a procedure for the validation of alpha-particle sources (exempt unsealed sources) to be used in experimental setups with liquefied gases at cryogenic temperatures (down to -196 °C) and high vacuum. These setups are of interest for the development and characterization of neutrino and dark matter detectors based on liquid argon, among others. Due to the high purity requirements, the sources have to withstand high vacuum and cryogenic temperatures for extended periods. The validation procedure has been applied to 241Am sources produced by electrodeposition.