8,530 research outputs found

    Resonances and weak interactions in D+π+ππ+D^+ \to\pi^+ \pi^- \pi^+ decays

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    We describe the ππ\pi\pi SS-wave in D+π+ππ+D^+ \to\pi^+ \pi^- \pi^+ decays using a unitary model for the ππ\pi\pi Final State Interactions (FSI). The three body decay is treated as a quasi two-body process where, at the weak vertex, the D meson decays into a resonance and a pion. The weak part of the decay amplitude is evaluated using the effective weak Hamiltonian within the factorization approximation.Comment: 4 pages. Contribution to the X Hadron Physics, Florianopolis-Brazil, March 26-31, 200

    Pseudoscalar-scalar transition form factors in covariant light front dynamics

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    In an explicitly covariant light-front formalism, we analyze transition form factors between pseudoscalar and scalar mesons. Application is performed in case of the Bf0(980)B \to f_0(980) transition in the full available transfer momentum range q2q^2.Comment: 4 pages, 4 figures. Talk given at the XXXIII International Conference on High Energy Physics, ICHEP06, Moscow, 26 July-02 Augus

    K* resonance effects on direct CP violation in B -> pi pi K

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    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are unchanged, but, the last paragraph of the Section "RESULTS AND SUMMARY" (now called "RESULTS AND DISCUSSION") has been replaced by a new Section "SUMMARY AND OUTLOOK".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

    Form factors in B->f0(980) and D->f0(980) transitions from dispersion relations

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    Within the dispersion relation approach we give the double spectral representation for space-like and time-like B-> f_0(980) and D-> f_0(980) transition form factors in the full q^2 range. The spectral densities, being the input of the dispersion relations, are obtained from a triangle diagram in the relativistic quark model.Comment: Talk given at MESON 2006, Krakow, 9-13 June 200

    Strong and Weak Interactions in B to pi+ pi- K Decays

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    To describe the weak three-body B decays into pi+ pi- K, we recently derived amplitudes based on two-body QCD factorization followed by pi+ pi- final state interactions in isoscalar S- and isovector P-waves. We study here the sensitivity of the results to the values of the B to f0(980) transition form factor and to the effective decay constant of the f0(980).Comment: Contribution to the Few Body 18 conference in Santos, Brazil, August 21-26, 2006, 5 pages, to be published in Nuclear Physics

    Multi-gene panel testing for hereditary cancer predisposition in unsolved high-risk breast and ovarian cancer patients.

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    PurposeMany women with an elevated risk of hereditary breast and ovarian cancer have previously tested negative for pathogenic mutations in BRCA1 and BRCA2. Among them, a subset has hereditary susceptibility to cancer and requires further testing. We sought to identify specific groups who remain at high risk and evaluate whether they should be offered multi-gene panel testing.MethodsWe tested 300 women on a multi-gene panel who were previously enrolled in a long-term study at UCSF. As part of their long-term care, all previously tested negative for mutations in BRCA1 and BRCA2 either by limited or comprehensive sequencing. Additionally, they met one of the following criteria: (i) personal history of bilateral breast cancer, (ii) personal history of breast cancer and a first or second degree relative with ovarian cancer, and (iii) personal history of ovarian, fallopian tube, or peritoneal carcinoma.ResultsAcross the three groups, 26 women (9%) had a total of 28 pathogenic mutations associated with hereditary cancer susceptibility, and 23 women (8%) had mutations in genes other than BRCA1 and BRCA2. Ashkenazi Jewish and Hispanic women had elevated pathogenic mutation rates. In addition, two women harbored pathogenic mutations in more than one hereditary predisposition gene.ConclusionsAmong women at high risk of breast and ovarian cancer who have previously tested negative for pathogenic BRCA1 and BRCA2 mutations, we identified three groups of women who should be considered for subsequent multi-gene panel testing. The identification of women with multiple pathogenic mutations has important implications for family testing

    Determination of sulfur and nitrogen compounds during the processing of dry fermented sausages and their relation to amino acid generation

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    © 2015 Elsevier Ltd. All rights reserved. The identification of odor-active sulfur and nitrogen compounds formed during the processing of dry fermented sausages was the objective of this study. In order to elucidate their possible origin, free amino acids (FAAs) were also determined. The volatile compounds present in the dry sausages were extracted using solvent assisted flavor evaporation (SAFE) and monitored by one and two-dimensional gas chromatography with different detectors: mass spectrometry (MS), nitrogen phosphorous (NPD), flame photometric (FPD) detectors, as well as gas chromatography-olfactometry. A total of seventeen sulfur and nitrogen compounds were identified and quantified. Among them, 2-acetyl-1-pyrroline was the most potent odor active compound, followed by methional, ethylpyrazine and 2,3-dihydrothiophene characterized by toasted, cooked potato, and nutty notes. The degradation of FAAs, generated during processing, was related to the production of aroma compounds, such as methionine forming methional and benzothiazole while ornithine was the precursor compound for 2-acetyl-1-pyrroline and glycine for ethylpyrazine.Financial support from AGL 2012-38884-C02-01 from MINECO (Spain), PROMETEO 2012-001 (GVA) and FEDER funds are fully acknowledged. The predoctoral scholarship and financial support from MINECO (BES-2010-030850 and EEBB-EEBB-I-13-05949) for the stay of S. Corral at Institute of Analytical Chemistry and Food Chemistry (Graz, Austria) is also acknowledged.Peer Reviewe

    Scalar meson properties from D-meson decays

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    Decay amplitudes of D(D_s)->f0(980)X, X=pi, K, are compared to experimental branching ratios with the aim of singling out the poorly known D->f0(980) transition form factor in these amplitudes. Since the other elements of the amplitudes are either calculable in an effective QCD theory using operator product expansion or are known from experiment (e.g. the pion and kaon decay constants), we can take advantage of these reactions to constrain the transition form factors obtained in relativistic quark models. In these models, the f0(980) wavefunction requires an unknown size parameter for both its non-strange ubar u(dbar d) and strange sbar s components, which we fit to the D(D_s) decay data.Comment: Talk given at the Few Body 18 conference in Santos, Brazil. 4 pages, to be published in Nuclear Physics
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