64 research outputs found

    Isotopic Production Cross Sections in Proton-Nucleus Collisions at 200 MeV

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    Intermediate mass fragments (IMF) from the interaction of 27^{27}Al, 59^{59}Co and 197^{197}Au with 200 MeV protons were measured in an angular range from 20 degree to 120 degree in the laboratory system. The fragments, ranging from isotopes of helium up to isotopes of carbon, were isotopically resolved. Double differential cross sections, energy differential cross sections and total cross sections were extracted.Comment: accepted by Phys. Rev.

    Chiral Symmetry and the Nucleon Structure Functions

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    The isospin asymmetry of the sea quark distribution as well as the unexpectedly small quark spin fraction of the nucleon are two outstanding discoveries recently made in the physics of deep-inelastic structure functions. We evaluate here the corresponding quark distribution functions within the framework of the chiral quark soliton model, which is an effective quark model of baryons maximally incorporating the most important feature of low energy QCD, i.e. the chiral symmetry and its spontaneous breakdown. It is shown that the model can explain qualitative features of the above-mentioned nucleon structure functions within a single framework, thereby disclosing the importance of chiral symmetry in the physics of high energy deep-inelastic scatterings.Comment: 20pages, LaTex, 5 Postscript figures A numerical error of the original version was corrected. The discussion on the regularization dependence of distribution functions has been added. A comparison with the low energy-scale parametrization of Gloeck, Reya and Vogt has been mad

    Gamow-Teller Strength Distribution for 37-Cl(p,n)37-Ar

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    This research was sponsored by the National Science Foundation Grant NSF PHY-931478

    Progress Report on E356

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    This research was sponsored by the National Science Foundation Grant NSF PHY-931478

    The Gamow-Teller Strength Function for 37-Cl → 37-Ar

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    This research was sponsored by the National Science Foundation Grant NSF PHY-931478

    The Crystal Ball Data Acquisition System

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    The data acquisition system for the Crystal Ball project at SLAC is described. A PDP-11/t55 using RSX-11M connected to the SLAC Triplex is the basis of the system. A "physics pipeline" allows physicists to write their own equipment-monitoring or physics tasks which require event sampling. As well, an interactive analysis package (MULTI) is in the pipeline. Histogram collection and display on the PDP are implemented using the Triplex histogramming package. Various interactive event displays are also implemented

    National surveillance for hemophilia inhibitors in the United States: Summary report of an expert meeting: National Inhibitor Surveillance in the U.S.

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    On March 12, 2012, the Centers for Disease Control and Prevention (CDC) held a meeting of its partners in hemophilia treatment, community-based organizations, industry, and government to review data and discuss implementation issues relevant to planned United States (U.S.) national inhibitor surveillance. Issues discussed included the current status of inhibitor surveillance in the United Kingdom (UK) and the US, the results of a US inhibitor surveillance feasibility study, proposed national surveillance schemes, laboratory testing and reporting issues and potential opportunities for future inhibitor-related research. It was concluded that implementation of a national program of inhibitor surveillance using standardized testing through an established public health registry along with patient and care provider education and targeted research provide the best opportunity to inform efforts to develop and evaluate effective prevention strategies

    Chiral Symmetry and the Nucleon Spin Structure Functions

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    We carry out a systematic investigation of twist-two spin dependent structure functions of the nucleon within the framework of the chiral quark soliton model (CQSM) by paying special attention to the role of chiral symmetry of QCD. The importance of chiral symmetry is illustrated through the good reproduction of the recent SLAC data for the neutron spin structure function g1n(x,Q2)g_1^n (x,Q^2). We also observe substantial difference between the predictions of the longitudinally polarized distribution functions and those of the transversity distribution functions. That the chiral symmetry may be responsible for this difference is seen in the isospin dependence of the corresponding first moments, i.e. the axial and tensor charges. The CQSM predicts gA(0)/gA(3)≃0.25g_A^{(0)} / g_A^{(3)} \simeq 0.25 for the ratio of the isoscalar to isovector axial charges, while gT(0)/gT(3)≃0.46g_T^{(0)} / g_T^{(3)} \simeq 0.46 for the ratio of the isoscalar to isovector tensor charges, which should be compared with the prediction gA(0)/gA(3)=gT(0)/gT(3)=3/5g_A^{(0)} / g_A^{(3)} = g_T^{(0)} / g_T^{(3)} = 3 / 5 of the constituent quark model or of the naive MIT bag model without proper account of chiral symmetry. Another prominent prediction of the CQSM is the opposite polarization of the uˉ\bar{u} and dˉ\bar{d} antiquarks, thereby indicating the SU(2) asymmetric sea quark (spin) polarization in the nucleon.Comment: 46pages, LaTeX, 16 Postscript figure
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