Higher charmonia and X, Y, Z states with screened potential

Journal Article · Fri May 01 04:00:00 EDT 2009 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.79.094004· OSTI ID:21308408

Baiqing, Li ^[1]; Kuangta, Chao ^[1]

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1. Department of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China)

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 charmoniumlike ''X, Y, Z'' states. We find the masses of higher charmonia with screened potential are considerably lower than those with unscreened potential. The {chi}{sub c2}(2P) mass agrees well with that of the Z(3930), and the mass of {psi}(4415) is compatible with {psi}(5S) rather than {psi}(4S). In particular, the discovered four Y states in the initial state radiation process, i.e., Y(4008), Y(4260), Y(4320/4360), Y(4660) may be assigned as the {psi}(3S), {psi}(4S), {psi}(3D), {psi}(6S) states, respectively. The X(3940) and X(4160) found in the double charmonium production in e{sup +}e{sup -} annihilation may be assigned as the {eta}{sub c}(3S) and {chi}{sub c0}(3P) states. Based on the calculated E1 transition widths for {chi}{sub c1}(2P){yields}{gamma}J/{psi} and {chi}{sub c1}(2P){yields}{gamma}{psi}(2S) and other results, we argue that the X(3872) may be a {chi}{sub c1}(2P) dominated charmonium state with some admixture of the D{sup 0}D*{sup 0} 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.

• OSTI ID: 21308408
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 9 Vol. 79; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANNIHILATION
ANTIQUARKS
B QUARKS
C QUARKS
COLOR MODEL
COMPARATIVE EVALUATIONS
D QUARKS
E1-TRANSITIONS
ELECTRONS
MASS
P STATES
PAIR PRODUCTION
PARTICLE DECAY
POSITRONS
POTENTIALS
PSI-4415 MESONS
QUARK-ANTIQUARK INTERACTIONS
SPECTRA
T QUARKS
U QUARKS