2,729 research outputs found

    Developing a Research Mentorship Program: The American Society of Pediatric Nephrology's Experience

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    Background: Most pediatric nephrologists work in academia. Mentor-mentee relationships provide support and guidance for successful research career. Mentorship program implementation is valuable in medical fields for providing research opportunities to young faculty. Methods: The American Society of Pediatric Nephrology (ASPN) established a research mentorship program to (a) assist with matching of appropriate mentor-mentee dyads and (b) establish metrics for desirable mentor-mentee outcomes with two independent components: (1) the grants review workshop, a short-term program providing mentor feedback on grant proposals, and (2) the longitudinal program, establishing long-term mentor-mentee relationships. Regular surveys of both mentors and mentees were reviewed to evaluate and refine the program. Results: Twelve mentees and 17 mentors participated in the grant review workshop and 19 mentees were matched to mentors in the longitudinal program. A review of NIH RePORTER data indicated that since 2014, 13 NIH grants have been awarded. Mentees in the longitudinal program reported that the program helped most with identifying an outside mentor, improving grant research content, and with general career development. Mentors perceived themselves to be most helpful in assisting with overall career plans. Email communications were preferred over phone or face-to-face communications. Mentees endorsed strong interest in staying in touch with their mentors and 100% of mentors expressed their willingness to serve in the future. Conclusion: This mentorship program was initiated and supported by a relatively small medical society and has shown early success in cultivating mentoring relationships for a future generation of clinician-scientists

    Dalitz Plot Analysis of the Decay D^+ --> K^- pi^+ pi^+ and Indication of a Low-Mass Scalar K pi Resonance

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    We study the Dalitz plot of the decay D^+ --> K^- pi^+ pi^+ with a sample of 15090 events from Fermilab experiment E791. Modeling the decay amplitude as the coherent sum of known K pi resonances and a uniform nonresonant term, we do not obtain an acceptable fit. If we allow the mass and width of the K^*_0(1430) to float, we obtain values consistent with those from PDG but the chi^2 per degree of freedom of the fit is still unsatisfactory. A good fit is found when we allow for the presence of an additional scalar resonance, with mass 797 +/- 19 +/- 43 MeV/c^2 and width 410 +/- 43 +/- 87 MeV/c^2. The mass and width of the K^*_0(1430) become 1459 +/- 7 +/- 5 MeV/c^2 and 175 +/- 12 +/- 12 MeV/c^2, respectively. Our results provide new information on the scalar sector in hadron spectroscopy.Comment: Accepted for publication in Physical Review Letter

    Study of the Ds+ππ+π+D^+_s \to \pi^- \pi^+ \pi^+ decay and measurement of f0f_0 masses and widths

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    From a sample of 848 ±\pm 44 Ds+ππ+π+D_s^+ \to \pi^- \pi^+ \pi^+ decays, we find Γ(Ds+ππ+π+)/Γ(Ds+ϕπ+)=0.245±0.0280.012+0.019\Gamma(D_s^+ \to \pi^- \pi^+ \pi^+) / \Gamma(D_s^+ \to \phi \pi^+) = 0.245 \pm 0.028^{+0.019}_{-0.012} . Using a Dalitz plot analysis of this three body decay, we find significant contributions from the channels ρ0(770)π+\rho^0(770)\pi^+, ρ0(1450)π+\rho^0(1450)\pi^+, f0(980)π+f_0(980)\pi^+, f2(1270)π+f_2(1270)\pi^+, and f0(1370)π+f_0(1370)\pi^+. We present also the values obtained for masses and widths of the resonances f0(980)f_0(980) and f0(1370)f_0(1370).Comment: 10 pages, 3 eps figure

    Search for the Flavor-Changing Neutral-Current Decays D+π+μ+μD^+\to \pi^+ \mu^+ \mu^- and D+π+e+eD^+\to \pi^+ e^+ e^-

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    We report the results of a search for the flavor-changing neutral-current decays D+π+μ+μD^+\rightarrow \pi^+ \mu^+ \mu^- and D+π+e+eD^+\rightarrow \pi^+ e^+ e^- in data from Fermilab charm hadroproduction experiment E791. No signal above background is found, and we obtain upper limits on branching fractions, B(D+π+μ+μ)<1.8×105B(D^+\rightarrow \pi^+ \mu^+ \mu^-) < 1.8 \times 10^{-5} and B(D+π+e+e)<6.6×105B(D^+\rightarrow \pi^+ e^+ e^-) < 6.6 \times 10^{-5}, at the 90\% confidence level.Comment: nine pages with figures; compressed, uuencoded postscrip

    Experimental evidence for a light and broad scalar resonance in D+ππ+π+D^+\to \pi^-\pi^+\pi^+ decay

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    From a sample of 1172±611172 \pm 61 D+ππ+π+D^+ \to \pi^- \pi^+ \pi^+ decay, we find Γ(D+ππ+π+)/Γ(D+Kπ+π+)=0.0311±0.00180.0026+0.0016\Gamma (D^+ \to \pi^- \pi^+ \pi^+) / \Gamma (D^+ \to K^- \pi^+ \pi^+) = 0.0311 \pm 0.0018 ^{+0.0016}_{-0.0026}. Using a coherent amplitude analysis to fit the Dalitz plot of this decays, we find strong evidence that a scalar resonance of mass 47823+24±17478^{+24}_{-23} \pm 17 MeV/c2c^2 and width 32440+42±21324^{+42}_{-40} \pm 21 MeV/c2c^2 accounts for approximately half of all decays.Comment: 10 pages, 3 eps figure

    Direct measurement of the pion valence quark momentum distribution, the pion light-cone wave function squared

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    We present the first direct measurements of the pion valence quark momentum distribution which is related to the square of the pion light-cone wave function. The measurements were carried out using data on diffractive dissociation of 500 GeV/c π\pi^- into di-jets from a platinum target at Fermilab experiment E791. The results show that the qqˉ>|q\bar {q}> light-cone asymptotic wave function, which was developed using perturbative QCD methods, describes the data well for Q210 (GeV/c)2Q^2 \sim 10 ~{\rm (GeV/c)^2} or more. We also measured the transverse momentum distribution of the diffractive di-jets.Comment: 13 pages, 4 figure

    Studies of the Response of the Prototype CMS Hadron Calorimeter, Including Magnetic Field Effects, to Pion, Electron, and Muon Beams

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    We report on the response of a prototype CMS hadron calorimeter module to charged particle beams of pions, muons, and electrons with momenta up to 375 GeV/c. The data were taken at the H2 and H4 beamlines at CERN in 1995 and 1996. The prototype sampling calorimeter used copper absorber plates and scintillator tiles with wavelength shifting fibers for readout. The effects of a magnetic field of up to 3 Tesla on the response of the calorimeter to muons, electrons, and pions are presented, and the effects of an upstream lead tungstate crystal electromagnetic calorimeter on the linearity and energy resolution of the combined calorimetric system to hadrons are evaluated. The results are compared with Monte Carlo simulations and are used to optimize the choice of total absorber depth, sampling frequency, and longitudinal readout segmentation.Comment: 89 pages, 41 figures, to be published in NIM, corresponding author: P de Barbaro, [email protected]

    Evidence for the Rare Decay B -> K*ll and Measurement of the B -> Kll Branching Fraction

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    We present evidence for the flavor-changing neutral current decay BK+B\to K^*\ell^+\ell^- and a measurement of the branching fraction for the related process BK+B\to K\ell^+\ell^-, where +\ell^+\ell^- is either an e+ee^+e^- or μ+μ\mu^+\mu^- pair. These decays are highly suppressed in the Standard Model, and they are sensitive to contributions from new particles in the intermediate state. The data sample comprises 123×106123\times 10^6 Υ(4S)BBˉ\Upsilon(4S)\to B\bar{B} decays collected with the Babar detector at the PEP-II e+ee^+e^- storage ring. Averaging over K()K^{(*)} isospin and lepton flavor, we obtain the branching fractions B(BK+)=(0.650.13+0.14±0.04)×106{\mathcal B}(B\to K\ell^+\ell^-)=(0.65^{+0.14}_{-0.13}\pm 0.04)\times 10^{-6} and B(BK+)=(0.880.29+0.33±0.10)×106{\mathcal B}(B\to K^*\ell^+\ell^-)=(0.88^{+0.33}_{-0.29}\pm 0.10)\times 10^{-6}, where the uncertainties are statistical and systematic, respectively. The significance of the BK+B\to K\ell^+\ell^- signal is over 8σ8\sigma, while for BK+B\to K^*\ell^+\ell^- it is 3.3σ3.3\sigma.Comment: 7 pages, 2 postscript figues, submitted to Phys. Rev. Let
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