Model-independent study of magnetic dipole transitions in quarkonium

Journal Article · Wed Mar 01 04:00:00 EST 2006 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PhysRevD.73.054005· OSTI ID:20776852

Brambilla, Nora; Yu, Jia; Vairo, Antonio ^[1]

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1. Dipartimento di Fisica dell'Universita di Milano and INFN, via Celoria 16, 20133 Milan (Italy)

We study magnetic dipole (M1) transitions between two quarkonia in the framework of nonrelativistic effective field theories of QCD. Relativistic corrections of relative order v{sup 2} are investigated in a systematic fashion. Nonperturbative corrections due to color-octet effects are considered for the first time and shown to vanish at relative order v{sup 2}. Exact, all order expressions for the relevant 1/m and 1/m{sup 2} magnetic operators are derived. The results allow us to scrutinize several potential model claims. In particular, we show that QCD excludes both contributions to the anomalous magnetic moment of the quarkonium induced by low-energy fluctuations and contributions to the magnetic dipole operators of the type induced by a scalar potential. Finally, we apply our results to the transitions J/{psi}{yields}{eta}{sub c}{gamma}, {upsilon}(1S){yields}{eta}{sub b}{gamma}, {upsilon}(2S){yields}{eta}{sub b}(2S){gamma}, {upsilon}(2S){yields}{eta}{sub b}{gamma}, {eta}{sub b}(2S){yields}{upsilon}(1S){gamma}, h{sub b}(1P){yields}{chi}{sub b0,1}(1P){gamma}, and {chi}{sub b2}(1P){yields}h{sub b}(1P){gamma} by assuming these quarkonium states in the weak-coupling regime. Our analysis shows that the J/{psi}{yields}{eta}{sub c}{gamma} width is consistent with a weak-coupling treatment of the charmonium ground state, while such a treatment for the hindered transition {upsilon}(2S){yields}{eta}{sub b}{gamma} appears difficult to accommodate within the CLEO III upper limit.

• OSTI ID: 20776852
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 5 Vol. 73; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
B QUARKS
C QUARKS
CESR STORAGE RING
CHARMONIUM
COLOR MODEL
CORRECTIONS
COUPLING
ETA MESONS
FLUCTUATIONS
GROUND STATES
HADRONIC PARTICLE DECAY
M1-TRANSITIONS
MAGNETIC DIPOLES
MAGNETIC MOMENTS
MULTIPARTICLE SPECTROMETERS
PARTICLE IDENTIFICATION
POTENTIALS
QUANTUM CHROMODYNAMICS
RELATIVISTIC RANGE
RESONANCE PARTICLES
SCALARS
T QUARKS
UPSILON-10023 MESONS
UPSILON-9460 MESONS