663 research outputs found
Proton lifetime bounds from chirally symmetric lattice QCD
We present results for the matrix elements relevant for proton decay in Grand
Unified Theories (GUTs). The calculation is performed at a fixed lattice
spacing a^{-1}=1.73(3) GeV using 2+1 flavors of domain wall fermions on
lattices of size 16^3\times32 and 24^3\times64 with a fifth dimension of length
16. We use the indirect method which relies on an effective field theory
description of proton decay, where we need to estimate the low energy
constants, \alpha = -0.0112(25) GeV^3 and \beta = 0.0120(26) GeV^3. We relate
these low energy constants to the proton decay matrix elements using leading
order chiral perturbation theory. These can then be combined with experimental
bounds on the proton lifetime to bound parameters of individual GUTs.Comment: 17 pages, 9 Figure
Trust, professionalism and regulation: a critical comparison of Medicine and Law
Background & Aims: Trust, professionalism and regulation are complex social phenomena, which are contextually dependent and dynamic. This project aims to explore the concept of ‘trust’ in Law and Medicine - questioning what it means to be a ‘trustworthy’ professional and how these understandings relate to ideas of professionalism and regulation. Methods: This study draws on a comprehensive review of the literature and interviews with thirty participants from within, or related to, the UK legal and medical professions. Participants included practitioners, those creating and implementing policy, and public representatives. Data was analysed using the ‘logics approach’ from Political Discourse Theory (PDT). This helped us draw out taken-for-granted ideas and beliefs about trust, professionalism and regulation and expose these to critique. Results: Participants highly valued patient/client trust, seeing it as fundamental to the functioning of their professional ‘service’. Trust was seen as attributed primarily to the individual practitioner and maintained through demonstrating measurable ‘professionalism’. Practitioners were understood to be individually responsible for preserving their image as a ‘good professional’, via evidencing their ‘professionalism’ to the patient/client and the regulator. Discussion: Current ways-of-thinking about trust permitted trust in individuals to be maintained, even when trust in the professions as a whole was challenged. However, for medical professionals particularly, this was predicated on a need to ‘evidence’ that one was a ‘good professional’ through intensive and continual regulation. This created an increased dependency on a ‘trust-industry’ of regulatory bodies and systems. This project critically questions how regulation shapes and impacts trust in the professions. It is a problem-driven approach, which seeks to break with current patterns of thinking and question: ‘what might be possible instead?’ This opens up an ideological space and new viewpoints, whereby audiences are encouraged to consider future change
Lattice QCD with mixed actions
We discuss some of the implications of simulating QCD when the action used
for the sea quarks is different from that used for the valence quarks. We
present exploratory results for the hadron mass spectrum and pseudoscalar meson
decay constants using improved staggered sea quarks and HYP-smeared overlap
valence quarks. We propose a method for matching the valence quark mass to the
sea quark mass and demonstrate it on UKQCD clover data in the simpler case
where the sea and valence actions are the same.Comment: 15 pages, 10 figures some minor modification to text and figures.
Accepted for publicatio
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