Charge-conjugation violating neutrino interactions in supernovae

The well known charge conjugation violating interactions in the Standard Model increase neutrino- and decrease anti-neutrino- nucleon cross sections. This impacts neutrino transport in core collapse supernovae through "recoil" corrections of order the neutrino energy $k$ over the nucleon mass $M$. All $k/M$ corrections to neutrino transport deep inside a protoneutron star are calculated from angular integrals of the Boltzmann equation. We find these corrections significantly modify neutrino currents at high temperatures. This produces a large mu and tau number for the protoneutron star and can change the ratio of neutrons to protons. In addition, the relative size of neutrino mean free paths changes. At high temperatures, the electron anti-neutrino mean free path becomes {\it longer} than that for mu or tau neutrinos.Comment: 14 pages, 2 included ps figures, subm. to Phys. Rev.

Measurement of the longitudinal diffusion of ionization electrons in the MicroBooNE detector

Abstract: Accurate knowledge of electron transport properties is vital to understanding the information provided by liquid argon time projection chambers (LArTPCs). Ionization electron drift-lifetime, local electric field distortions caused by positive ion accumulation, and electron diffusion can all significantly impact the measured signal waveforms. This paper presents a measurement of the effective longitudinal electron diffusion coefficient, DL, in MicroBooNE at the nominal electric field strength of 273.9 V/cm. Historically, this measurement has been made in LArTPC prototype detectors. This represents the first measurement in a large-scale (85 tonne active volume) LArTPC operating in a neutrino beam. This is the largest dataset ever used for this measurement. Using a sample of ∼70,000 through-going cosmic ray muon tracks tagged with MicroBooNE's cosmic ray tagger system, we measure DL = 3.74+0.28 -0.29 cm2/s

Using the physical properties of artefacts to manage through‐life knowledge flows in the built environment: an initial exploration

Effective through‐life management of built facilities requires effective through‐life knowledge management to support it. The KIM (Immortal Information and Through‐Life Knowledge Management) project attempted to develop such an approach, based on a dichotomy of knowledge and information. Knowledge is conceived in terms of communities of practice. An initial philosophical analysis demonstrates deficiencies in this conception. Drawing inspiration from production theory, a tripartite analysis is offered, suggesting that knowledge flows consist of: social practices, information and physical properties. Literature on physical properties from design studies, production management and ethnomethodology is briefly reviewed to demonstrate the information bearing functions of physical properties. Fieldwork conforming to the unique adequacy requirement of methods was carried out on construction sites, in hotel and hospital facilities during the use stage of their life cycles. Safety barriers on construction sites were found to have informational properties beyond their function as a physical barrier. The quality of information delivered by wayfinding signs was found to depend upon both the physical placement of the signs in relation to the surrounding environment and the physical layout of the sign itself. It was found that social practices are institutionalized to repair the knowledge flow when the physically instantiated wayfinding system breaks down. Finally, through the investigation of practices surrounding emergency resuscitation equipment, it was found that if the physical properties of information are not designed to mesh with the work practices of the setting, this will lead to a breakdown in the knowledge flow. It is suggested that elements of knowledge management, ethnomethodology, production management and design studies might be integrated to form the basis of a hybrid discipline