757 research outputs found

    Canonical Charmonium Interpretation for Y(4360) and Y(4660)

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    In this work, we consider the canonical charmonium assignments for Y(4360) and Y(4660). Y(4660) is good candidate of 53S1\rm 5 ^3S_1 ccˉc\bar{c} state, the possibility of Y(4360) as a 33D1\rm 3 ^3D_1 ccˉc\bar{c} state is studied, and the charmonium hybrid interpretation of Y(4360) can not be excluded completely. We evaluate the e+ee^{+}e^{-} leptonic widths, E1 transitions, M1 transitions and the open flavor strong decays of Y(4360) and Y(4660). Experimental tests for the charmonium assignments are suggested.Comment: 32 pages, 4 figure

    Strange-Beauty Meson Production at ppˉp\bar p Colliders

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    The production rates and transverse momentum distributions of the strange-beauty mesons BsB_s and BsB_s^* at ppˉp\bar p colliders are calculated assuming fragmentation is the dominant process. Results are given for the Tevatron in the large transverse momentum region, where fragmentation is expected to be most important.Comment: Minor changes in the discussion section. Also available at http://www.ph.utexas.edu/~cheung/paper.htm

    On the π\pi and KK as qqˉq \bar q Bound States and Approximate Nambu-Goldstone Bosons

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    We reconsider the two different facets of π\pi and KK mesons as qqˉq \bar q bound states and approximate Nambu-Goldstone bosons. We address several topics, including masses, mass splittings between π\pi and ρ\rho and between KK and KK^*, meson wavefunctions, charge radii, and the KπK-\pi wavefunction overlap.Comment: 15 pages, late

    The Non-Coding Transcriptome of Prostate Cancer: Implications for Clinical Practice

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    Prostate cancer (PCa) is the most common type of cancer and the second leading cause of cancer-related death in men. Despite extensive research, the molecular mechanisms underlying PCa initiation and progression remain unclear, and there is increasing need of better biomarkers that can distinguish indolent from aggressive and life-threatening disease. With the advent of advanced genomic technologies in the last decade, it became apparent that the human genome encodes tens of thousands non-protein-coding RNAs (ncRNAs) with yet to be discovered function. It is clear now that the majority of ncRNAs exhibit highly specific expression patterns restricted to certain tissues and organs or developmental stages and that the expression of many ncRNAs is altered in disease and cancer, including cancer of the prostate. Such ncRNAs can serve as important biomarkers for PCa diagnosis, prognosis, or prediction of therapy response. In this review, we give an overview of the different types of ncRNAs and their function, describe ncRNAs relevant for the diagnosis and prognosis of PCa, and present emerging new aspects of ncRNA research that may contribute to the future utilization of ncRNAs as clinically useful therapeutic targets

    Decay Constants and Semileptonic Decays of Heavy Mesons in Relativistic Quark Model

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    We investigate the BB and DD mesons in the relativistic quark model by applying the variational method with the Gaussian wave function. We calculate the Fermi momentum parameter pFp_{_F}, and obtain pF=0.500.54p_{_F} = 0.50 \sim 0.54 GeV, which is almost independent of the input parameters, αs\alpha_s, mbm_b, mcm_c and mspm_{sp}. We then calculate the ratio fBf_B/fDf_D, and obtain the result which is larger, by the factor of about 1.3, than MD/MB\sqrt{M_D / M_B} given by the naive nonrelativistic analogy. This result is in a good agreement with the recent Lattice calculations. We also calculate the ratio (MBMB)(M_{B^*}-M_{B})/(MDMD)(M_{D^*}-M_{D}). In these calculations the wave function at origin ψ(0)\psi (0) is essential. We also determine pFp_{_F} by comparing the theoretical prediction of the ACCMM model with the lepton energy spectrum of BeνXB \rightarrow e \nu X from the recent ARGUS analysis, and find that pF=0.27 ± 0.270.22p_{_F}=0.27~\pm~^{0.22}_{0.27} GeV, when we use mc=1.5m_c=1.5 GeV. However, this experimentally determined value of pFp_{_F} is strongly dependent on the value of input parameter mcm_c.Comment: 15 pages (Latex) (uses epsfig.sty, 1 figure appended as a uuencoded compressed ps-file

    Leptonic widths of high excitations in heavy quarkonia

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    Agreement with the measured electronic widths of the ψ(4040)\psi(4040), ψ(4415)\psi(4415), and Υ(11019)\Upsilon (11019) resonances is shown to be reached if two effects are taken into account: a flattening of the confining potential at large distances and a total screening of the gluon-exchange interaction at r\ga 1.2 fm. The leptonic widths of the unobserved Υ(7S)\Upsilon(7S) and ψ(5S)\psi(5S) resonances: Γe+e(Υ(7S))=0.11\Gamma_{e^+e^-}(\Upsilon (7S))=0.11 keV and Γ(ψ(5S))0.54\Gamma(\psi(5S))\approx 0.54 keV are predicted.Comment: 11 pages revtex

    The decay constants of pseudoscalar mesons in a relativistic quark model

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    The decay constants of pseudoscalar mesons are calculated in a relativistic quark model which assumes that mesons are made of a valence quark antiquark pair and of an effective vacuum like component. The results are given in terms of quark masses and of some free parameters entering the expression of the internal wave functions of the mesons. By using the pion and kaon decay constants Fπ+=130.7 MeV, FK+=159.8 MeVF_{\pi^+}=130.7~MeV,~F_{K^+}=159.8~MeV to fix the parameters of the model one gets 60 MeVFD+185 MeV, 95 MeVFDs230 MeV, 80 MeVFB+205 MeV60~MeV\leq F_{D^+}\leq 185~MeV,~95~MeV\leq F_{D_s}\leq230~MeV,~80~MeV\leq F_{B^+}\leq205~MeV for the light quark masses mu=5.1 MeV, md=9.3 MeV, ms=175 MeVm_u=5.1~MeV,~m_d=9.3~MeV,~m_s=175~MeV and the heavy quark masses in the range: 1. GeVmc1.6 GeV, 4.1 GeVmb4.5 GeV1.~GeV\leq m_c\leq1.6~GeV,~4.1~GeV\leq m_b\leq4.5~GeV. In the case of light neutral mesons one obtains with the same set of parameters Fπ0138 MeV, Fη 130 MeV,Fη 78 MeVF_{\pi^0}\approx 138~MeV,~F_\eta\approx~130~MeV,F_{\eta'} \approx~78~MeV. The values are in agreement with the experimental data and other theoretical results.Comment: 11 pages, LaTe

    Di-electron and two-photon widths in charmonium

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    The vector and pseudoscalar decay constants are calculated in the framework of the Field Correlator Method. Di-electron widths: Γee(J/ψ)=5.41\Gamma_{ee}(J/\psi)=5.41 keV, Γee(ψ(3686))=2.47\Gamma_{ee}(\psi'(3686))=2.47 keV, Γee(ψ(3770))=0.248\Gamma_{ee}(\psi''(3770))=0.248 keV, in good agreement with experiment, are obtained with the same coupling, αs=0.165\alpha_s=0.165, in QCD radiative corrections. We show that the larger αs=0.191±0.004\alpha_s=0.191\pm 0.004 is needed to reach agreement with experiment for Γγγ(ηc)=7.22\Gamma_{\gamma\gamma}(\eta_c)=7.22 keV, Γγγ(χ(3P0))=3.3\Gamma_{\gamma\gamma} (\chi(^3P_0))=3.3 keV, Γγγ(χ(3P2))=0.54\Gamma_{\gamma\gamma}(\chi(^3P_2))= 0.54 keV, and also for Γ(J/ψ3g)=59.5\Gamma(J/\psi\to 3g)=59.5 keV, Γ(J/ψγ2g)=5.7\Gamma(J/\psi\to \gamma 2g)=5.7 keV. Meanwhile even larger αs=0.238\alpha_s=0.238 gives rise to good description of Γ(ψ3g)=52.7\Gamma(\psi'\to 3g)=52.7 keV, Γ(ψγ2g)=3.5\Gamma(\psi'\to \gamma 2g)= 3.5 keV, and provides correct ratio of the branching fractions: B(J/ψlighthadrons)B(ψlighthadrons)=0.24.\frac{\mathcal{B}(J/\psi\to light hadrons)}{\mathcal{B}(\psi'\to light hadrons)}=0.24.Comment: 8 pages, no figure

    Large corrections to asymptotic FηcγF_{\eta_c \gamma} and FηbγF_{\eta_b \gamma} in the light-cone perturbative QCD

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    The large-Q2Q^2 behavior of ηc\eta_c-γ\gamma and ηb\eta_b-γ\gamma transition form factors, Fηcγ(Q2)F_{\eta_c\gamma}(Q^2) and Fηbγ(Q2)F_{\eta_b\gamma}(Q^2) are analyzed in the framework of light-cone perturbative QCD with the heavy quark (cc and bb) mass effect, the parton's transverse momentum dependence and the higher helicity components in the light-cone wave function are respected. It is pointed out that the quark mass effect brings significant modifications to the asymptotic predictions of the transition form factors in a rather broad energy region, and this modification is much severer for Fηbγ(Q2)F_{\eta_b\gamma}(Q^2) than that for Fηcγ(Q2)F_{\eta_c\gamma}(Q^2) due to the bb-quark being heavier than the cc-quark. The parton's transverse momentum and the higher helicity components are another two factors which decrease the perturbative predictions. For the transition form factor Fηcγ(Q2)F_{\eta_c\gamma}(Q^2), they bring sizable corrections in the present experimentally accessible energy region (Q210GeV2Q^2 \leq 10 GeV^2). For the transition form factor Fηbγ(Q2)F_{\eta_b\gamma}(Q^2), the corrections coming from these two factors are negligible since the bb-quark mass is much larger than the parton's average transverse momentum. The coming e+ee^+ e^- collider (LEP2) will provide the opportunity to examine these theoretical predictions.Comment: 8 pages, RevTex, 5 PostScript figure
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