The Numerical Range of C* ψ Cφ and Cφ C* ψ

Study of ψ ′ and χ c decays as feed - down sources of J / ψ hadro - production

The interpretation of the J/ψ suppression patterns observed in nuclear collisions, at CERN and RHIC, as a signature of the formation of a deconfined phase of QCD matter, requires knowing which fractions of the measured J/ψ yields, in pp collisions, are due to decays of heavier charmonium states. From a detailed analysis of the available mid-rapidity charmonium hadro-production cross sections, o...

C*-Algebra numerical range of quadratic elements

It is shown that the result of Tso-Wu on the elliptical shape of the numerical range of quadratic operators holds also for the C*-algebra numerical range.

Resonances from J / Ψ and Ψ ′ Decays

The Institute of High Energy Physics at Beijing runs an electron-positron collider (BEPC) with a general purpose solenoidal detector, the Beijing Spectrometer (BES)[1], which is designed to study exclusive final states in ee annihilations at the center of mass energy from 3000 to 5600 MeV. In this energy range, the largest cross sections are at the J/Ψ(3097) and Ψ(3686) resonant peaks. At prese...

The c̄c purity of ψ ( 3770 ) and ψ ′ challenged

Ratio of Photoproduction Rates of J/ψ and ψ(2S)

There are different approaches for diffractive photoproduction of charmonia. Recently, a new approach is proposed, in which charm quarks are taken as heavy quarks and the nonperturbative effect related to charmonia can be handled with nonrelativistic QCD. The interaction between the cc̄ pair and the initial hadron is through exchange of soft gluons. The exchange of soft gluons can be studied wit...