368 research outputs found

    A genetic polymorphism and its genetic effects on goat myogenin gene in intron 1

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    Single nucleotide polymorphisms (SNPs) of the myogenin (MyoG) gene were tested using primer induced restriction fragment length polymorphism assay-polymerase chain reaction (PIRA-PCR) from Bore goat and its upgrading offspring to Tangshan diary goat (including F1, F2 and F3). The effects of the myogenin gene on the birth weight, 1-month body weight and the weaning weight were also analyzed. On the basis of the DNA sequence of the goat myogenin gene (FJ607135), primers were designed to amplify myogenin gene. The result showed that one polymorphism (transition of g.558C>T) was found in intron 1 of goat myogenin gene, in which two alleles (A and B) and three genotypes (AA, AB and BB) were examined. The distributions of three genotypes were basically identical in four goat populations, and allele A was the dominant gene. The effect of the myogenin genotypes on the birth weight, 1-month body weight and the weaning weight were all not significant (P > 0.05) due to the small number of BB gaots; however, the values of AA genotype goats and AB genotype goats were obviously higher than those of BB genotype goats for three growth traits, in the order of AA > AB > BB. These results suggest that the myogenin genotype has some effects on partial growth traits of goat, and selecting the individuals with A allele could be favorable to the birth weight, 1-month body weight and the weaning weight.Key words: goats, myogenin gene, primer induced restriction fragment length polymorphism assay-polymerase chain reaction (PIRA-PCR), genetic polymorphisms, genetic effects

    Resonances in J/ψ→ϕπ+π−J/\psi \to \phi \pi ^+\pi ^- and ϕK+K−\phi K^+K^-

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    A partial wave analysis is presented of J/ψ→ϕπ+π−J/\psi \to \phi \pi ^+\pi ^- and ϕK+K−\phi K^+K^- from a sample of 58M J/ψJ/\psi events in the BES II detector. The f0(980)f_0(980) is observed clearly in both sets of data, and parameters of the Flatt\' e formula are determined accurately: M=965±8M = 965 \pm 8 (stat) ±6\pm 6 (syst) MeV/c2^2, g1=165±10±15g_1 = 165 \pm 10 \pm 15 MeV/c2^2, g2/g1=4.21±0.25±0.21g_2/g_1 = 4.21 \pm 0.25 \pm 0.21. The ϕππ\phi \pi \pi data also exhibit a strong ππ\pi \pi peak centred at M=1335M = 1335 MeV/c2^2. It may be fitted with f2(1270)f_2(1270) and a dominant 0+0^+ signal made from f0(1370)f_0(1370) interfering with a smaller f0(1500)f_0(1500) component. There is evidence that the f0(1370)f_0(1370) signal is resonant, from interference with f2(1270)f_2(1270). There is also a state in ππ\pi \pi with M=1790−30+40M = 1790 ^{+40}_{-30} MeV/c2^2 and Γ=270−30+60\Gamma = 270 ^{+60}_{-30} MeV/c2^2; spin 0 is preferred over spin 2. This state, f0(1790)f_0(1790), is distinct from f0(1710)f_0(1710). The ϕKKˉ\phi K\bar K data contain a strong peak due to f2′(1525)f_2'(1525). A shoulder on its upper side may be fitted by interference between f0(1500)f_0(1500) and f0(1710)f_0(1710).Comment: 17 pages, 6 figures, 1 table. Submitted to Phys. Lett.

    Measurement of the Branching Fraction of J/psi --> pi+ pi- pi0

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    Using 58 million J/psi and 14 million psi' decays obtained by the BESII experiment, the branching fraction of J/psi --> pi+ pi- pi0 is determined. The result is (2.10+/-0.12)X10^{-2}, which is significantly higher than previous measurements.Comment: 9 pages, 8 figures, RevTex

    Search for K_S K_L in psi'' decays

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    K_S K_L from psi'' decays is searched for using the psi'' data collected by BESII at BEPC, the upper limit of the branching fraction is determined to be B(psi''--> K_S K_L) < 2.1\times 10^{-4} at 90% C. L. The measurement is compared with the prediction of the S- and D-wave mixing model of the charmonia, based on the measurements of the branching fractions of J/psi-->K_S K_L and psi'-->K_S K_L.Comment: 5 pages, 1 figur

    First Measurements of eta_c Decaying into K^+K^-2(pi^+pi^-) and 3(pi^+pi^-)

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    The decays of eta_c to K^+K^-2(pi^+pi^-) and 3(pi^+pi^-) are observed for the first time using a sample of 5.8X10^7 J/\psi events collected by the BESII detector. The product branching fractions are determined to be B(J/\psi-->gamma eta_c)*B(eta_c-->K^+K^-pi^+pi^-pi^+pi^-)=(1.21+-0.32+- 0.23)X10^{-4},B(J/ψ−−>gammaetac)∗B(etac−−>K∗0Kˉ∗0pi+pi−)=(1.29+−0.43+−0.32)X10−4,B(J/\psi-->gamma eta_c)*B(eta_c-->K^{*0}\bar{K}^{*0}pi^+pi^-)= (1.29+-0.43+-0.32)X10^{-4}, and (J/\psi-->gamma eta_c)* B(eta_c-->pi^+pi^-pi^+pi^-pi^+pi^-)= (2.59+-0.32+-0.48)X10^{-4}. The upper limit for eta_c-->phi pi^+pi^-pi^+pi^- is also obtained as B(J/\psi-->gamma eta_c)*B(eta_c--> phi pi^+pi^-pi^+pi^-)< 6.03 X10^{-5} at the 90% confidence level.Comment: 11 pages, 4 figure

    First observation of psi(2S)-->K_S K_L

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    The decay psi(2S)-->K_S K_L is observed for the first time using psi(2S) data collected with the Beijing Spectrometer (BESII) at the Beijing Electron Positron Collider (BEPC); the branching ratio is determined to be B(psi(2S)-->K_S K_L) = (5.24\pm 0.47 \pm 0.48)\times 10^{-5}. Compared with J/psi-->K_S K_L, the psi(2S) branching ratio is enhanced relative to the prediction of the perturbative QCD ``12%'' rule. The result, together with the branching ratios of psi(2S) decays to other pseudoscalar meson pairs (\pi^+\pi^- and K^+K^-), is used to investigate the relative phase between the three-gluon and the one-photon annihilation amplitudes of psi(2S) decays.Comment: 5 pages, 4 figures, 2 tables, submitted to Phys. Rev. Let

    Study of psi(2S) decays to X J/psi

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    Using J/psi -> mu^+ mu^- decays from a sample of approximately 4 million psi(2S) events collected with the BESI detector, the branching fractions of psi(2S) -> eta J/psi, pi^0 pi^0 J/psi, and anything J/psi normalized to that of psi(2S) -> pi^+ pi^- J/psi are measured. The results are B(psi(2S) -> eta J/psi)/B(psi(2S) -> pi^+ pi^- J/psi) = 0.098 \pm 0.005 \pm 0.010, B(psi(2S) -> pi^0 pi^0 J/psi)/B(psi(2S) -> pi^+ pi^- J/psi) = 0.570 \pm 0.009 \pm 0.026, and B(psi(2S) -> anything J/psi)/B(psi(2S) -> pi^+ pi^- J/psi) = 1.867 \pm 0.026 \pm 0.055.Comment: 13 pages, 8 figure

    Observation of a ppb mass threshoud enhancement in \psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p}) decay

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    The decay channel ψ′→π+π−J/ψ(J/ψ→γppˉ)\psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p}) is studied using a sample of 1.06×1081.06\times 10^8 ψ′\psi^\prime events collected by the BESIII experiment at BEPCII. A strong enhancement at threshold is observed in the ppˉp\bar{p} invariant mass spectrum. The enhancement can be fit with an SS-wave Breit-Wigner resonance function with a resulting peak mass of M=1861−13+6(stat)−26+7(syst)MeV/c2M=1861^{+6}_{-13} {\rm (stat)}^{+7}_{-26} {\rm (syst)} {\rm MeV/}c^2 and a narrow width that is Γ<38MeV/c2\Gamma<38 {\rm MeV/}c^2 at the 90% confidence level. These results are consistent with published BESII results. These mass and width values do not match with those of any known meson resonance.Comment: 5 pages, 3 figures, submitted to Chinese Physics

    Search for Charged Higgs Bosons in e+e- Collisions at \sqrt{s} = 189 GeV

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    A search for pair-produced charged Higgs bosons is performed with the L3 detector at LEP using data collected at a centre-of-mass energy of 188.6 GeV, corresponding to an integrated luminosity of 176.4 pb^-1. Higgs decays into a charm and a strange quark or into a tau lepton and its associated neutrino are considered. The observed events are consistent with the expectations from Standard Model background processes. A lower limit of 65.5 GeV on the charged Higgs mass is derived at 95 % confidence level, independent of the decay branching ratio Br(H^{+/-} -> tau nu)

    Search for the standard model Higgs boson at LEP

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