5,238 research outputs found
K* resonance effects on direct CP violation in B -> pi pi K
Charged and neutral B decays into two charged pions and a charged or a
neutral kaon are analyzed within the QCD factorization scheme where final state
interactions before and after hadronization are included. The K*(892) and
K*(1430) resonance effects are taken into account using the presently known
pion-Kaon strange vector and scalar form factors. The weak decay amplitudes,
which are calculated at leading power in Lambda_QCD/m_b and at the
next-to-leading order in the strong coupling constant, include the hard
scattering and annihilation contributions. The end point divergences of these
weak final state interactions are controlled by two complex parameters
determined through a fit to the available effective mass and helicity angle
distribution, CP asymmetry and K*(892) branching ratio data. The predicted
K*(1430) branching ratios and the calculated direct CP violation asymmetries
are compared to the Belle and BABAR Collaboration data.Comment: Comments: 22 pages, 2 figures and 3 tables. In this new version, the
results are unchanged, but, the last paragraph of the Section "RESULTS AND
SUMMARY" (now called "RESULTS AND DISCUSSION") has been replaced by a new
Section "SUMMARY AND OUTLOOK". To appear in Physical Review
Forbidden induced subgraphs and the price of connectivity for feedback vertex set.
Let fvs(G) and cfvs(G) denote the cardinalities of a minimum feedback vertex set and a minimum connected feedback vertex set of a graph G, respectively. For a graph class G, the price of connectivity for feedback vertex set (poc-fvs) for G is defined as the maximum ratio cfvs(G)/fvs(G) over all connected graphs G in G. It is known that the poc-fvs for general graphs is unbounded. We study the poc-fvs for graph classes defined by a finite family H of forbidden induced subgraphs. We characterize exactly those finite families H for which the poc-fvs for H-free graphs is bounded by a constant. Prior to our work, such a result was only known for the case where |H|=1
Sigma pole position and errors of a once and twice subtracted dispersive analysis of pi-pi scattering data
We show how the new precise data on kaon decays together with forward
dispersion relations, sum rules and once- and twice-subtracted
Roy's equations allow for a precise determination of the sigma meson pole
position. We present a comparison and a study of the different sources of
uncertainties when using either once- or twice-subtracted Roy's equations to
analyze the data. Finally we present a preliminary determination of the sigma
pole from the constrained dispersive data analysis.Comment: 4 pages, 6 figures. Contribution to the proceedings of the QCD08 14th
International QCD Conference. 7-12th July 2008 Montpellier (France); one
reference removed, changed errors in Eqs (4), (5) and (7
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Premier John Jay: The Most Important Man in America
When John Jay returned from France in 1784, the Confederation Congress asked him to become Secretary for Foreign Affairs. After negotiating favorable terms for the department of foreign affairs and getting Congress to move the seat of government to New York City, Jay accepted the position. For the next five years Jay served as the de facto prime minister of the United States. His 500 reports to Congress on all diplomatic matters and many domestic concerns provided much needed guidance for Congress. He, in fact, was the glue that held the loose alliance of states together during the difficult postwar depression years. Many of his policies were adopted by his successor, Thomas Jefferson, who served as America's first secretary of state in the Washington administration
Massachusetts Historical Society, “The Adams Family Papers: An Electronic Archive”- Review of \u3ci\u3eMy Dearest Friend: Letters of Abigail and John Adams. Edited by Margaret A. Hogan and C. James Taylor\u3c/i\u3e
My Dearest Friend contains 289 letters “selected from the entire corpus” of the Adams letters from 1762 to 1801 and “is meant to show both the consistency of their relationship and the evolution of the family through the entire founding era.” A three-page epilogue on the death of Abigail consists of a short headnote and two letters exchanged between John and John Quincy Adams. All but three of the letters in My Dearest Friend are in the Adams Family manuscript collection given by the Adams family to the Massachusetts Historical Society (MHS) in 1956. The letters were all microfilmed on 608 reels by the MHS in the 1950s and sold to research libraries throughout the world. The Abigail and John letters appear on the MHS Web site (www.masshist.org) at “The Adams Family Papers: An Electronic Archive.” (See below.) Abigail and John’s letters also appear among the volumes of The Adams Family Correspondence published by The Bel - knap Press of Harvard University Press. Nine volumes have been published to date, covering the years through 1793. All of the published Adams volumes appear on the MHS Web site and are also digitally available on Rotunda, University of Virginia Press
Holographic Operator Mixing and Quasinormal Modes on the Brane
We provide a framework for calculating holographic Green's functions from
general bilinear actions and fields obeying coupled differential equations in
the bulk. The matrix-valued spectral function is shown to be independent of the
radial bulk coordinate. Applying this framework we improve the analysis of
fluctuations in the D3/D7 system at finite baryon density, where the
longitudinal perturbations of the world-volume gauge field couple to the scalar
fluctuations of the brane embedding. We compute the spectral function and show
how its properties are related to the quasinormal mode spectrum. We study the
crossover from the hydrodynamic diffusive to the reactive regime and the
movement of quasinormal modes as functions of temperature and density. We also
compute their dispersion relations and find that they asymptote to the
lightcone for large momenta.Comment: 42 pages, 12 figure
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