9,297 research outputs found

    Low-lying even parity meson resonances and spin-flavor symmetry

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    A study is presented of the ss-wave meson-meson interactions involving members of the ρ\rho-nonet and of the π\pi-octet. The starting point is an SU(6) spin-flavor extension of the SU(3) flavor Weinberg-Tomozawa Lagrangian. SU(6) symmetry breaking terms are then included to account for the physical meson masses and decay constants, while preserving partial conservation of the axial current in the light pseudoscalar sector. Next, the TT-matrix amplitudes are obtained by solving the Bethe Salpeter equation in coupled-channel with the kernel built from the above interactions. The poles found on the first and second Riemann sheets of the amplitudes are identified with their possible Particle Data Group (PDG) counterparts. It is shown that most of the low-lying even parity PDG meson resonances, specially in the JP=0+J^P=0^+ and 1+1^+ sectors, can be classified according to multiplets of the spin-flavor symmetry group SU(6). The f0(1500)f_0(1500), f1(1420)f_1(1420) and some 0+(2++)0^+(2^{++}) resonances cannot be accommodated within this SU(6) scheme and thus they would be clear candidates to be glueballs or hybrids. Finally, we predict the existence of five exotic resonances (I3/2I \ge 3/2 and/or Y=2|Y|=2) with masses in the range 1.4--1.6 GeV, which would complete the 27127_1, 10310_3, and 10310_3^* multiplets of SU(3)\otimesSU(2).Comment: 43 pages, 2 figures, 61 tables. Improved discussion of Section II. To appear in Physical Review

    The therapy of gefitinib towards breast cancer partially through reversing breast cancer biomarker arginine

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    Background: Breast cancer remains the leading reason of cancer death among women worldwide, and gefitinib is the efficient drug for breast cancer.Aims: To use targeted metabolomics method to elucidate the therapeutic mechanism of gefitinib through profiling the amino acids.Methods: Healthy women (n=56) and women with breast cancer (n=60) were enrolled in Affiliated Yuhuangding hospital, medical college of Qingdao University from 2012-2014. API 3200 triple quadrupole mass spectrometer was used to analyze the serum samples.Results: The concentration of amino acids was compared between healthy women and women with breast cancers. Compared with the healthy women, the concentration of arginine in breast cancer women significantly decreased (p<0.0001). To show the representative capability of arginine towards the pathogenesis of breast cancers, the receiver operating characteristic (ROC) curve was drawn, and the area under the curve (AUC) was calculated to be 0.96 ± 0.02, indicating the high predictive capability of arginine for breast cancer . The reversing ability of gefitinib towards the level of arginine was further determined, and 1 month treatment of gefitinib (500 mg/day) significantly reversed the arginine level of breast cancer patients (p<0.0001)Conclusion: The therapy of gefitinib towards breast cancer through reversing breast cancer biomarker arginine was demonstrated.Keywords: Breast cancer, arginine, metabolomics, gefitini

    Study of Long Distance Contributions to KnπννˉK\to n\pi\nu\bar{\nu}

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    We calculate long distance contributions to $K\to\pi\nu\bar{\nu}\,,\ \pi\pi\nu\bar{\nu},and, and \pi\pi\pi\nu\bar{\nu}modeswithintheframeworkofchiralperturbationtheory.Wefindthatthesecontributionstodecayratesof modes within the framework of chiral perturbation theory. We find that these contributions to decay rates of K\to \pi\nu\bar{\nu}and and K\to \pi\pi\nu\bar{\nu}$ in the chiral logarithmic approximation are at least seven orders of magnitude suppressed relative to those from the short distance parts. The long distance effects in this class of decays are therefore negligible.Comment: 13 pages, LaTeX fil

    Recent Developments in Chiral Unitary Dynamics of Resonances

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    In this talk I summarize recent findings made on the description of axial vector mesons as dynamically generated states from the interaction of peseudoscalar mesons and vector mesons, dedicating some attention to the two K1(1270)K_1(1270) states. Then I review the generation of open and hidden charm scalar and axial states. Finally, I present recent results showing that the low lying 1/2+1/2^+ baryon resonances for S=-1 can be obtained as bound states or resonances of two mesons and one baryon in coupled channels dynamics.Comment: Talk at the International Conference on Hadron Physics, Troia07, Canakkale, Turkey, Sep. 2007 and at the Chiral Symmetry in Hadron and Nuclear Physics Workshop, Chiral07, Osaka, November 200

    Route to Larger Pulse Energy in Ultrafast Fiber Lasers

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    A systematic study of Zr and Sn isotopes in the Relativistic Mean Field theory

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    The ground-state properties of Zr and Sn isotopes are studied within the relativistic mean field theory. Zr and Sn isotopes have received tremendous attention due to various reasons, including the predicted giant halos in the neutron-rich Zr isotopes, the unique feature of being robustly spherical in the region of 100^{100}Sn \sim 132^{132}Sn and the particular interest of Sn isotopes to nuclear astrophysics. Furthermore, four (semi-) magic neutron numbers, 40, 50, 82 and 126, make these two isotopic chains particularly important to test the pairing correlations and the deformations in a microscopic model. In the present work, we carry out a systematic study of Zr and Sn isotopes from the proton drip line to the neutron drip line with deformation effects, pairing correlations and blocking effects for nuclei with odd number of neutrons properly treated. A constrained calculation with quadrupole deformations is performed to find the absolute minimum for each nucleus on the deformation surface. All ground-state properties, including the separation energies, the odd-even staggerings, the nuclear radii, the deformations and the single-particle spectra are analyzed and discussed in detail.Comment: the final version to appear in Modern Physics Letters A. more figures, discussions, and references added. the data remain unchange
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