Effective Lagrangian for Two-photon and Two-gluon Decays of P-wave Heavy Quarkonium chi_c(0,2) and chi_(b0,2) states

Journal Article · Wed Jun 03 00:00:00 EDT 2009 · Phys.Rev.D79:094016,2009

DOI:https://doi.org/10.1103/PhysRevD.79.094016· OSTI ID:953850

Lansberg, J P; Pham, T N

In the traditional non-relativistic bound state calculation, the two-photon decay amplitudes of the P-wave {chi}{sub c0,2} and {chi}{sub b0,2} states depend on the derivative of the wave function at the origin which can only be obtained from potential models. However by neglecting the relative quark momenta, the decay amplitude can be written as the matrix element of a local heavy quark field operator which could be obtained from other processes or computed with QCD sum rules technique or lattice simulation. Following the same line as in recent work for the two-photon decays of the S-wave {eta}{sub c} and {eta}{sub b} quarkonia, we show that the effective Lagrangian for the two-photon decays of the P-wave {chi}{sub c0,2} and {chi}{sub b0,2} is given by the heavy quark energy-momentum tensor local operator or its trace, the {anti Q}Q scalar density and that the expression for {chi}{sub c0} two-photon and two-gluon decay rate is given by the f{sub {chi}{sub c0}} decay constant and is similar to that of {eta}{sub c} which is given by f{sub {eta}{sub c}}. From the existing QCD sum rules value for f{sub {chi}{sub c0}}, we get 5 keV for the {chi}{sub c0} two-photon width, somewhat larger than measurement, but possibly with large uncertainties.

• Research Organization: Stanford Linear Accelerator Center (SLAC)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 953850
• Report Number(s): SLAC-PUB-13566; arXiv:0903.1562
• Journal Information: Phys.Rev.D79:094016,2009, Journal Name: Phys.Rev.D79:094016,2009
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BOUND STATE
DECAY
DECAY AMPLITUDES
DENSITY
ENERGY-MOMENTUM TENSOR
FIELD OPERATORS
LAGRANGIAN FUNCTION
MATRIX ELEMENTS
Phenomenology-HEP
HEPPH
QUANTUM CHROMODYNAMICS
QUARKONIUM
QUARKS
SCALARS
SIMULATION
SUM RULES
WAVE FUNCTIONS
WIDTH