23,231 research outputs found

    Decay Constants of Pseudoscalar Mesons to Two Loops in Three-Flavor Partially Quenched χ\chiPT

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    This paper presents a first study of the decay constants of the charged, or flavor-off-diagonal, pseudoscalar mesons to two loops for three flavors of sea quarks, in Partially Quenched Chiral Perturbation Theory (PQχ\chiPT). Explicit analytical expressions up to O(p6){\cal O}(p^6) in the momentum expansion are given. The calculations have been performed within the supersymmetric formulation of PQχ\chiPT. We also present some numerical results to indicate the size of the corrections.Comment: 14

    Leading logarithms for the nucleon mass

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    Within the heavy baryon chiral perturbation theory approach, we have studied the leading logarithm behaviour of the nucleon mass up to four-loop order exactly and we present some results up to six-loop order as well as an all-order conjecture. The same methods allow to calculate the main logarithm multiplying the terms with fractional powers of the quark mass. We calculate thus the coefficients of m2n+1log(n1)(μ2/m2)m^{2n+1}\log^{(n-1)}(\mu^2/m^2) and m2n+2logn(μ2/m2)m^{2n+2}\log^n(\mu^2/m^2), with mm the lowest-order pion mass. A side result is the leading divergence for a general heavy baryon loop integral.Comment: 24p, misprints corrected, some minor reformulation

    Leading chiral logarithms for the nucleon mass

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    We give a short introduction to the calculation of the leading chiral logarithms, and present the results of the recent evaluation of the leading logarithm series for the nucleon mass within the heavy baryon theory. The presented results are the first example of leading logarithm calculation in the nucleon ChPT. We also discuss some regularities observed in the leading logarithmical series for nucleon mass. The talk has been presented at "Quark Confinement and the Hadron Spectrum XI".Comment: 8 pages, 3 figure, proceeding of the XIth international conference on Quark Confinement and the Hadron Spectrum, September 8-12 2014, St.Peterburg, Russi

    An Algorithm to Determine Peer-Reviewers

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    The peer-review process is the most widely accepted certification mechanism for officially accepting the written results of researchers within the scientific community. An essential component of peer-review is the identification of competent referees to review a submitted manuscript. This article presents an algorithm to automatically determine the most appropriate reviewers for a manuscript by way of a co-authorship network data structure and a relative-rank particle-swarm algorithm. This approach is novel in that it is not limited to a pre-selected set of referees, is computationally efficient, requires no human-intervention, and, in some instances, can automatically identify conflict of interest situations. A useful application of this algorithm would be to open commentary peer-review systems because it provides a weighting for each referee with respects to their expertise in the domain of a manuscript. The algorithm is validated using referee bid data from the 2005 Joint Conference on Digital Libraries.Comment: Rodriguez, M.A., Bollen, J., "An Algorithm to Determine Peer-Reviewers", Conference on Information and Knowledge Management, in press, ACM, LA-UR-06-2261, October 2008; ISBN:978-1-59593-991-
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