Loading [MathJax]/jax/output/HTML-CSS/jax.js
40
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Evidence for the Direct Two-Photon Transition from ψ(3686) to J/ψ

      Preprint
      , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,   , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          The two-photon transition ψ(3686)γγJ/ψ is studied in a sample of 106 million ψ(3686) decays collected by the BESIII detector. The branching fraction is measured to be (3.1±0.6(\unitstat)+0.81.0(\unitsyst))×104 using J/ψe+e and J/ψμ+μ decays, and its upper limit is estimated to be 4.5×104 at the 90% conference level. This work represents the first measurement of a two-photon transition among charmonium states. The orientation of the ψ(3686) decay plane and the J/ψ polarization in this decay are also studied. In addition, the product branching fractions of sequential E1 transitions ψ(3686)γχcJ,χcJγJ/ψ(J=0,1,2) are reported.

          Related collections

          Most cited references4

          • Record: found
          • Abstract: found
          • Article: found
          Is Open Access

          Coherent Exclusive Exponentiation For Precision Monte Carlo Calculations

          We present the new Coherent Exclusive Exponentiation (CEEX), the older Exclusive Exponentiation (EEX) and the semi-analytical Inclusive Exponentiation (IEX) for the process e+efˉf+nγ, f=μ,τ,d,u,s,c,b with validity for centre of mass energies from τ lepton threshold to 1TeV, that is for LEP1, LEP2, SLC, future Linear Colliders, b,c,τ-factories etc. They are based on Yennie-Frautschi-Suura exponentiation. In CEEX effects due to photon emission from initial beams and outgoing fermions are calculated in QED up to second-order, including all interference effects. Electroweak corrections are included in first-order, at the amplitude level. Beams can be polarized longitudinally and transversely, and all spin correlations are incorporated in an exact manner. EEX is more primitive, lacks initial-final interferences, but it is valuable for testing the newer CEEX. IEX provides us set of a sophisticated semi-analytical formulas for the total cross section and selected inclusive distributions which are mainly used for cross-checks of the MC results. We analyse numerical results at the Z-peak 189 GeV and 500 GeV for simple kinematical cuts (comparisons with IEX) and for realistic experimental cuts. Physical precision and technical precision are determined for the total cross section and for the charge asymmetry.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: found
            Is Open Access

            Charmonium levels near threshold and the narrow state X(3872)π+π\jpsi

            We explore the influence of open-charm channels on charmonium properties, and profile the 1:3D2, 1:3D3 and 2:1P1 charmonium candidates for X(3872). The favored candidates, the 1:3D2 and 1:3D3 levels, both have prominent radiative decays. The 1:3D2 might be visible in the D0ˉD0 channel, while the dominant decay of the 1:3D3 state should be into DˉD. We propose that additional discrete charmonium levels can be discovered as narrow resonances of charmed and anticharmed mesons.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: found
              Is Open Access

              Higher Charmonia and X,Y,Z states with Screened Potential

              We incorporate the color-screening effect due to light quark pair creation into the heavy quark-antiquark potential, and investigate the effects of screened potential on the spectrum of higher charmonium. We calculate the masses, electromagnetic decays, and E1 transitions of charmonium states in the screened potential model, and propose possible assignments for the newly discovered charmonium or charmonium-like "X,Y,Z" states. We find the masses of higher charmonia with screened potential are considerably lower than those with unscreened potential. The χc2(2P) mass agrees well with that of the Z(3930), and the mass of ψ(4415) is compatible with ψ(5S) rather than ψ(4S). In particular, the discovered four Y states in the ISR process, i.e., Y(4008),Y(4260),Y(4320/4360),Y(4660) may be assigned as the ψ(3S),ψ(4S),ψ(3D),ψ(6S) states respectively. The X(3940) and X(4160) found in the double charmonium production in e+e annihilation may be assigned as the ηc(3S) and χc0(3P) states. Based on the calculated E1 transition widths for χc1(2P)γJ/ψ and χc1(2P)γψ(2S) and other results, we argue that the X(3872) may be a χc1(2P) dominated charmonium state with some admixture of the D0ˉD0 component. Possible problems encountered in these assignments and comparisons with other interpretations for these X,Y,Z states are discussed in detail. We emphasize that more theoretical and experimental investigations are urgently needed to clarify these assignments and other interpretations.
                Bookmark

                Author and article information

                Journal
                01 April 2012
                2012-10-31
                Article
                10.1103/PhysRevLett.109.172002
                1204.0246
                2274f5ad-4ef0-4f49-8e91-f81997232a97

                http://creativecommons.org/licenses/by/3.0/

                History
                Custom metadata
                Phys. Rev. Lett. 109, 172002 (2012)
                6 pages, 3 figures, 2 tables
                hep-ex hep-ph

                Comments

                Comment on this article

                scite_
                0
                0
                0
                0
                Smart Citations
                0
                0
                0
                0
                Citing PublicationsSupportingMentioningContrasting
                View Citations

                See how this article has been cited at scite.ai

                scite shows how a scientific paper has been cited by providing the context of the citation, a classification describing whether it supports, mentions, or contrasts the cited claim, and a label indicating in which section the citation was made.

                Similar content415

                Most referenced authors24