The Color-Octet intrinsic charm in η′\eta^\prime and B→η′XB\to \eta^\prime X decays

Color-octet mechanism for the decay B\to \eta^\prime X is proposed to explain the large branching ratio of Br(B\to \eta^\prime X)\sim 1\times 10^{-3} recently announced by CLEO. We argue that the inclusive \eta^\prime production in B decays may dominantly come from the Cabbibo favored b\to (\bar c c)_8s process where \bar c c pair is in a color-octet configuration, and followed by the nonperturbative transition (\bar c c)_8\to \eta^\prime X. The color-octet intrinsic charm component in the higher Fock states of \eta^\prime is crucial and is induced by the strong coupling of \eta^\prime to gluons via QCD axial anomaly.Comment: 9 pages, RevTex, 1 PS figur

Glueball Interpretation of ξ\xi(2230)

On the basis of the results of $\xi(2230)\rightarrow\pi^{+}\pi^{-}, p\bar{p}$ and $K\bar{K}$, measured by the BES Collaboration in radiative J/$\psi$ decays, combined with the upper limit of Br($\xi\rightarrow p\bar{p}$)Br($\xi\rightarrow K\bar{K}$), measured by PS185 experiment, we argue that the distinctive properties of $\xi$(2230), the flavor-symmetric decays and the narrow partial decay widths to $\pi\pi$ and $K\bar{K}$ as well as its copious production in radiative J/$\psi$ decay, would strongly favor the glueball interpretation of $\xi$(2230).Comment: Latex file, no figure

A note on possible interpretations for the DSJ+(2632)D_{SJ}^+(2632) observed by SELEX

We suggest some possible interpretations for the $D_{SJ}^+(2632)$ observed by SELEX. The $D_{SJ}^+(2632)$ could be the first radial excitation of the $1^-$ ground state $\rm{D_s}^*$(2112), and its unusual decay patten might be hopefully explained by the node structure of the wave functions. In addition, the $D_{SJ}^+(2632)$ could also be a $c\bar sg$ hybrid state or a $(cs)_{3^*}-(\bar s\bar s)_{3}$ (diquark-antidiquark) bound state.Comment: final version to appear in Phys. Lett. B, references adde

A Crucial Test for Color-Octet Production Mechanism in Z^0 Decays

The direct production rates of $D$-wave charmonia in the decays of $Z^0$ is evaluated. The color-octet production processes $Z^0\rightarrow ^3D_J(c\bar c) q\bar q$ are shown to have distinctively large branching ratios, the same order of magnitude as that of $J/\psi$ prodution, as compared with other $D$-wave charmonium production mechanisms. This may suggest a crucial channel to test the color-octet mechanism as well as to observe the $D$-wave charmonium states in $Z^0$ decays. In addition, a signal for the $^3D_J$ charmonium as strong as $J/\psi$ or $\psi^\prime$ with large transverse momentum at the Tevatron should also be observed.Comment: 14 pages in LaTex (3 figures in PS-file

Gluon fragmentation to ^3D_J quarkonia

We present a calculation of the leading order QCD fragmentation functions for gluons to split into spin-triplet D-wave quarkonia. We apply them to evaluate the gluon fragmentation contributions to inclusive ^3D_J quarkonium production at large transverse momentum processes like the Tevatron and find that the D-wave quarkonia, especially the charmonium 2^{--} state, could be observed through color-octet mechanism with present luminosity. Since there are distinctively large gaps between the contributions of two different (i.e, color-singlet and color-octet) quarkonium production mechanisms, our results may stand as a unique test to NRQCD color-octet quarkonium production mechanism.Comment: 15 pages in LaTex (2 figures in PS-file

Dietary patterns in obese pregnant women; influence of a behavioral intervention of diet and physical activity in the UPBEAT randomized controlled trial.

BACKGROUND: Understanding dietary patterns in obese pregnant women will inform future intervention strategies to improve pregnancy outcomes and the health of the child. The aim of this study was to investigate the effect of a behavioral intervention of diet and physical activity advice on dietary patterns in obese pregnant woman participating in the UPBEAT study, and to explore associations of dietary patterns with pregnancy outcomes. METHODS: In the UPBEAT randomized controlled trial, pregnant obese women from eight UK multi-ethnic, inner-city populations were randomly assigned to receive a diet/physical activity intervention or standard antenatal care. The dietary intervention aimed to reduce glycemic load and saturated fat intake. Diet was assessed using a food frequency questionnaire (FFQ) at baseline (15(+0)-18(+6) weeks' gestation), post intervention (27(+0)-28(+6) weeks) and in late pregnancy (34(+0)-36(+0) weeks). Dietary patterns were characterized using factor analysis of the baseline FFQ data, and changes compared in the control and intervention arms. Patterns were related to pregnancy outcomes in the combined control/intervention cohort (n = 1023). RESULTS: Four distinct baseline dietary patterns were defined; Fruit and vegetables, African/Caribbean, Processed, and Snacks, which were differently associated with social and demographic factors. The UPBEAT intervention significantly reduced the Processed (-0.14; 95% CI -0.19, -0.08, P <0.0001) and Snacks (-0.24; 95% CI -0.31, -0.17, P <0.0001) pattern scores. In the adjusted model, baseline scores for the African/Caribbean (quartile 4 compared with quartile 1: OR = 2.46; 95% CI 1.41, 4.30) and Processed (quartile 4 compared with quartile 1: OR = 2.05; 95% CI 1.23, 3.41) patterns in the entire cohort were associated with increased risk of gestational diabetes. CONCLUSIONS: In a diverse cohort of obese pregnant women an intensive dietary intervention improved Processed and Snack dietary pattern scores. African/Caribbean and Processed patterns were associated with an increased risk of gestational diabetes, and provide potential targets for future interventions. TRIAL REGISTRATION: Current controlled trials; ISRCTN89971375

Possible retardation effects of quark confinement on the meson spectrum

The reduced Bethe-Salpeter equation with scalar confinement and vector gluon exchange is applied to quark-antiquark bound states. The so called intrinsic flaw of Salpeter equation with static scalar confinement is investigated. The notorious problem of narrow level spacings is found to be remedied by taking into consideration the retardation effect of scalar confinement. Good fit for the mass spectrum of both heavy and light quarkomium states is then obtained.Comment: 14 pages in LaTex for

Pseuduscalar Heavy Quarkonium Decays With Both Relativistic and QCD Radiative Corrections

We estimate the decay rates of $\eta_c\rightarrow 2\gamma$, $\eta_c'\rightarrow 2\gamma$, and $J/\psi\rightarrow e^+ e^-$, $\psi^\prime\rightarrow e^+e^-$, by taking into account both relativistic and QCD radiative corrections. The decay amplitudes are derived in the Bethe-Salpeter formalism. The Bethe-Salpeter equation with a QCD-inspired interquark potential are used to calculate the wave functions and decay widths for these $c\bar{c}$ states. We find that the relativistic correction to the ratio $R\equiv \Gamma (\eta_c \rightarrow 2\gamma)/ \Gamma (J/ \psi \rightarrow e^+ e^-)$ is negative and tends to compensate the positive contribution from the QCD radiative correction. Our estimate gives $\Gamma(\eta_c \rightarrow 2\gamma)=(6-7) ~keV$ and $\Gamma(\eta_c^\prime \rightarrow 2\gamma)=2 ~keV$, which are smaller than their nonrelativistic values. The hadronic widths $\Gamma(\eta_c \rightarrow 2g)=(17-23) ~MeV$ and $\Gamma(\eta_c^\prime \rightarrow 2g)=(5-7)~MeV$ are then indicated accordingly to the first order QCD radiative correction, if $\alpha_s(m_c)=0.26-0.29$. The decay widths for $b\bar b$ states are also estimated. We show that when making the assmption that the quarks are on their mass shells our expressions for the decay widths will become identical with that in the NRQCD theory to the next to leading order of $v^2$ and $\alpha_s$.Comment: 14 pages LaTex (2 figures included

D-wave Charmonium Production in e+e−e^+e^- Annihilation at s=10.6\sqrt{s}=10.6 GeV

We calculate the D-wave charmonium production in $e^+e^-$ annihilation at BELLE and BABAR at $\sqrt{s}=10.6$ GeV using the nonrelativistic QCD factorization formalism, including color singlet and color octet contributions. We analyze the contributions of various processes for $\delta_J(J=1,2)$ production. We find that both the color singlet and color octet channels may give substantial contributions, and the production rates are estimated to be $\sigma (\delta_1)\simeq 0.043-0.16pb$ and $\sigma (\delta_2)\simeq 0.094-0.29pb$, which, however, are very sensitive to the choice of the color octet matrix elements of the D-wave charmonium states. The measurement of D-wave charmonium production at BABAR and BELLE in the future will be very helpful to test the color octet mechanism and to determine the color octet matrix elements.Comment: 9 pages, 1 figure, final version to appear in Physics Letters