12,640 research outputs found

    Complete Study of Hadroproduction of a Υ\Upsilon Meson Associated with a Prompt J/ψJ/\psi

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    We present the first complete study of Υ\Upsilon and prompt J/ψJ/\psi production from single-parton scattering, including the complete O(αS6)\mathcal{O}(\alpha_S^6) color-singlet contribution, the O(αS2α2)\mathcal{O}(\alpha_S^2\alpha^2) electroweak contribution, the complete nonrelativistic S-wave and P-wave color-octet contribution as well as the feeddown contribution. Our study was motivated by the recent evidence reported by D0 Collaboration of prompt J/ψJ/\psi and Υ\Upsilon simultaneous production at the Tevatron. With our complete evaluation, we are able to refine the determination of the double parton scattering contribution made by D0 Collaboration. We find that the effective cross section characterizing the importance of double-parton scatterings is σeff8.2\sigma_{\rm eff}\le 8.2 mb at 68%68\% confidence level from the D0 measurement.Comment: 11 pages, 4 figures, 4 tables; v2: journal version, update the references and fix a few typo

    Search for C=+C=+ charmonium and XYZ states in e+eγ+He^+e^-\to \gamma+ H at BESIII

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    Within the framework of nonrelativistic quantum chromodynamics, we study the production of C=+C=+ charmonium states HH in e+eγ + He^+e^-\to \gamma~+~H at BESIII with H=ηc(nS)H=\eta_c(nS) (n=1, 2, 3, and 4), χcJ(nP)\chi_{cJ}(nP) (n=1, 2, and 3), and 1D2(nD)^1D_2(nD) (n=1 and 2). The radiative and relativistic corrections are calculated to next-to-leading order for SS and PP wave states. We then argue that the search for C=+C=+ XYZXYZ states such as X(3872)X(3872), X(3940)X(3940), X(4160)X(4160), and X(4350)X(4350) in e+eγ + He^+e^-\to \gamma~+~H at BESIII may help clarify the nature of these states. BESIII can search XYZXYZ states through two body process e+eγHe^+e^-\to \gamma H, where HH decay to J/ψπ+πJ/\psi \pi^+\pi^-, J/ψϕJ/\psi \phi, or DDˉD \bar D. This result may be useful in identifying the nature of C=+C=+ XYZXYZ states. For completeness, the production of C=+C=+ charmonium in e+eγ+ He^+e^-\to \gamma +~H at B factories is also discussed.Comment: Comments and suggestions are welcome. References are update

    A reversal coarse-grained analysis with application to an altered functional circuit in depression

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    Introduction: When studying brain function using functional magnetic resonance imaging (fMRI) data containing tens of thousands of voxels, a coarse-grained approach – dividing the whole brain into regions of interest – is applied frequently to investigate the organization of the functional network on a relatively coarse scale. However, a coarse-grained scheme may average out the fine details over small spatial scales, thus rendering it difficult to identify the exact locations of functional abnormalities. Methods: A novel and general approach to reverse the coarse-grained approach by locating the exact sources of the functional abnormalities is proposed. Results: Thirty-nine patients with major depressive disorder (MDD) and 37 matched healthy controls are studied. A circuit comprising the left superior frontal gyrus (SFGdor), right insula (INS), and right putamen (PUT) exhibit the greatest changes between the patients with MDD and controls. A reversal coarse-grained analysis is applied to this circuit to determine the exact location of functional abnormalities. Conclusions: The voxel-wise time series extracted from the reversal coarse-grained analysis (source) had several advantages over the original coarse-grained approach: (1) presence of a larger and detectable amplitude of fluctuations, which indicates that neuronal activities in the source are more synchronized; (2) identification of more significant differences between patients and controls in terms of the functional connectivity associated with the sources; and (3) marked improvement in performing discrimination tasks. A software package for pattern classification between controls and patients is available in Supporting Information
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