Towards a precision computation of f_Bs in quenched QCD

We present a computation of the decay constant f_Bs in quenched QCD. Our strategy is to combine new precise data from the static approximation with an interpolation of the decay constant around the charm quark mass region. This computation is the first step in demonstrating the feasability of a strategy for f_B in full QCD. The continuum limits in the static theory and at finite mass are taken separately and will be further improved.Comment: Lattice2003(heavy), 3 pages, 2 figure

Non-perturbative renormalization of the static axial current in two-flavour QCD

We perform the non-perturbative renormalization of matrix elements of the static-light axial current by a computation of its scale dependence in lattice QCD with two flavours of massless O(a) improved Wilson quarks. The regularization independent factor that relates any running renormalized matrix element of the axial current in the static effective theory to the renormalization group invariant one is evaluated in the Schroedinger functional scheme, where in this case we find a significant deviation of the non-perturbative running from the perturbative prediction. An important technical ingredient to improve the precision of the results consists in the use of modified discretizations of the static quark action introduced earlier by our collaboration. As an illustration how to apply the renormalization of the static axial current presented here, we connect the bare matrix element of the current to the B_s-meson decay constant in the static approximation for one value of the lattice spacing, a ~ 0.08 fm, employing large-volume N_f=2 data at beta=5.3.Comment: 33 pages including figures and tables, latex2e, uses JHEP3.cls; version published in JHEP, small additions, results unchange

How Public Is the Internet? A Conversation on the Nature of Human Interactions On-line and the Implications for Research Methods

In the past decade, ???virtual??? research???empirical investigations conducted via the Internet???has increased dramatically across a variety of disparate disciplines. Areas such as cybersecurity and encryption, digital government and citizenship, consumer health informatics, and user behavior in online spaces have emerged to become signature iSchool research areas, often shared with particular disciplinary heritages (e.g., computer science, political science and communication, public health, and sociology???respectively, but not exclusively). In addition, the field of Information Science is dominated by research developing or using emerging technologies. These new technologies often occupy a gray area in which ethical issues either have not been sufficiently well-defined or push against existing definitions. Questions surrounding the ???public??? nature of the internet and Web 2.0-era information technologies have also emerged and have become increasingly urgent given the tightening of federal, state and University regulations as they relate to the protection of human subjects. At the convergence of multiple disciplinary and methodological perspectives, Information Science researchers are well-positioned to become more active participants in both scholarly and institutional conversations regarding the appropriate risks and benefits that participants in online research studies might be subject to. Critiques of IRB inconsistencies exist, what we need is a thoughtful and thorough community response to the innately complex nature of virtual research and a map which can guide us towards the future and the study of twenty-first century systems, selves and societies. Our goal for this wildcard event, is to generate a lively and rigorous debate which accomplishes the following three goals: 1) extends the dialogue within the Information Science field concerning the beneficence and respect for participants in online research; 2) enumerates a set of best practices for iSchool researchers in relation to conducting approved research on-line and; 3) moves us towards the process of drafting an iSchool set of ethical guidelines related to virtual research

Editorial overview: Membrane traffic and cell polarity

No abstract available

A strategy for implementing non-perturbative renormalisation of heavy-light four-quark operators in the static approximation

We discuss the renormalisation properties of the complete set of $\Delta B = 2$ four-quark operators with the heavy quark treated in the static approximation. We elucidate the role of heavy quark symmetry and other symmetry transformations in constraining their mixing under renormalisation. By employing the Schroedinger functional, a set of non-perturbative renormalisation conditions can be defined in terms of suitable correlation functions. As a first step in a fully non-perturbative determination of the scale-dependent renormalisation factors, we evaluate these conditions in lattice perturbation theory at one loop. Thereby we verify the expected mixing patterns and determine the anomalous dimensions of the operators at NLO in the Schroedinger functional scheme. Finally, by employing twisted-mass QCD it is shown how finite subtractions arising from explicit chiral symmetry breaking can be avoided completely.Comment: 41 pages, 6 figure

The Electrostatic Screening Length in Concentrated Electrolytes Increases with Concentration

According to classical electrolyte theories interactions in dilute (low ion density) electrolytes decay exponentially with distance, with the Debye screening length the characteristic length-scale. This decay length decreases monotonically with increasing ion concentration, due to effective screening of charges over short distances. Thus within the Debye model no long-range forces are expected in concentrated electrolytes. Here we reveal, using experimental detection of the interaction between two planar charged surfaces across a wide range of electrolytes, that beyond the dilute (Debye-Huuckel) regime the screening length increases with increasing concentration. The screening lengths for all electrolytes studied - including aqueous NaCl solutions, ionic liquids diluted with propylene carbonate, and pure ionic liquids - collapse onto a single curve when scaled by the dielectric constant. This non-monotonic variation of the screening length with concentration, and its generality across ionic liquids and aqueous salt solutions, demonstrates an important characteristic of concentrated electrolytes of substantial relevance from biology to energy storage.Comment: This document is the unedited authors' version of a Submitted Work that was subsequently accepted for publication in the Journal of Physical Chemistry Letters, copyright American Chemical Society, after peer review. To access the final edited and published work see http://pubsdc3.acs.org/articlesonrequest/AOR-EW6FuIC6wIh6D9qqEeH

Quark bilinear step scaling functions and their continuum limit extrapolation

Some new results on nonperturbative renormalisation of quark bilinears in quenched QCD with Schroedinger Functional techniques are presented. Special emphasis is put on a study of the universality of the continuum limit for step scaling functions computed with different levels of O(a) improvement.Comment: Lattice2003(improve), 3 pages, 3 figure

Lattice QCD and the Schwarz alternating procedure

A numerical simulation algorithm for lattice QCD is described, in which the short- and long-distance effects of the sea quarks are treated separately. The algorithm can be regarded, to some extent, as an implementation at the quantum level of the classical Schwarz alternating procedure for the solution of elliptic partial differential equations. No numerical tests are reported here, but theoretical arguments suggest that the algorithm should work well also at small quark masses.Comment: Plain TeX source, 20 pages, figures include

Tapestry of Tears: An Autoethnography of Leadership, Personal Transformation, and Music Therapy in Humanitarian Aid in Bosnia Herzegovina

In the fall of 2003 I was invited to lead a team of music therapists in Bosnia and Herzegovina (BiH), a country that had been recently savaged by two brutal inter-ethnic wars. The program operated out of the Pavarotti Music Centre on the East side of Mostar, a divided city in the southwest region of BiH. My journey over the next four years was epically challenged by my immersion into the complexities of post-conflict recovery, and the cultural confusion that followed the atrocities of those wars. Transformation and change not only characterized the world in which I worked, but also paralleled internal processes proceeding silently within me. As a music therapist I have always worked within a framework of cultural constancy. In post-conflict societies, we become involved in a colossal moving fray of change. This dissertation is an autoethnography that uses heartfelt, reflective writing with the purpose of gaining a deeper understanding of my identity as a leader, as a music therapist, and as a cultural being in these sometimes difficult, but life-enhancing, four years. Together with academic perspectives and performative writing techniques, it explores a trail of thematic material that emerged during a confusing, ambiguous repatriation period in the years following my time in Bosnia. The autoethnography, an evocative expression of phenomenological research, is a conversation with self and with distant others who inhabit a time frame in the past, and thus informs an emergent narrative that carves its own path throughout the eight chapters. Ultimately, the dissertation aims toward a deeper understanding of my own culpability as a leader of a small multi-ethnic team in Mostar, BiH, and the implications this may have for arts-based fieldwork practice in post conflict regions. This dissertation is accompanied by seven supplemental files: 1 Mp4 video and 6 blog post pdf files. The electronic version of this Dissertation is at Ohiolink ETD Center, http://etd.ohiolink.edu and AURA http://aura.antioch.edu