Two-photon widths of the {chi}{sub cJ} states of charmonium

Journal Article · Sat Nov 01 04:00:00 EDT 2008 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.78.091501· OSTI ID:21254588

Ecklund, K M ^[1]; Love, W; Savinov, V ^[2]; Lopez, A; Mendez, H; Ramirez, J ^[3]; Ge, J Y; Miller, D H; Shipsey, I P. J.; Xin, B ^[4]; Adams, G S; Anderson, M; Cummings, J P; Danko, I; Hu, D; Moziak, B; Napolitano, J ^[5]; He, Q; Insler, J; Muramatsu, H ^[6]

---

1. State University of New York at Buffalo, Buffalo, New York 14260 (United States)
2. University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States)
3. University of Puerto Rico, Mayaguez, Puerto Rico 00681 (Puerto Rico)
4. Purdue University, West Lafayette, Indiana 47907 (United States)
5. Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)
6. University of Rochester, Rochester, New York 14627 (United States)

Using a data sample of 24.5x10{sup 6} {psi}(2S) the reactions {psi}(2S){yields}{gamma}{chi}{sub cJ}, {chi}{sub cJ}{yields}{gamma}{gamma} have been studied for the first time to determine the two-photon widths of the {chi}{sub cJ} states of charmonium in their decay into two photons. The measured quantities are B({psi}(2S){yields}{gamma}{chi}{sub c0})xB({chi}{sub c0}{yields}{gamma}{gamma})=(2.17{+-}0.32{+-}0.10)x10{sup -5} and B({psi}(2S){yields}{gamma}{chi}{sub c2})xB({chi}{sub c2}{yields}{gamma}{gamma})=(2.68{+-}0.28{+-}0.15)x10{sup -5}. Using values for B({psi}(2S){yields}{gamma}{chi}{sub c0,c2}) and {gamma}({chi}{sub c0,c2}) from the literature the two-photon widths are derived to be {gamma}{sub {gamma}}{sub {gamma}}({chi}{sub c0})=(2.36{+-}0.35{+-}0.22) keV, {gamma}{sub {gamma}}{sub {gamma}}({chi}{sub c2})=(0.66{+-}0.07{+-}0.06) keV, and R{identical_to}{gamma}{sub {gamma}}{sub {gamma}}({chi}{sub c2})/{gamma}{sub {gamma}}{sub {gamma}}({chi}{sub c0})=0.278{+-}0.050{+-}0.036. The importance of the measurement of R is emphasized. For the forbidden transition, {chi}{sub c1}{yields}{gamma}{gamma}, an upper limit of {gamma}{sub {gamma}}{sub {gamma}}({chi}{sub c1})<0.03 keV is established.

• OSTI ID: 21254588
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 9 Vol. 78; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
B MESONS
CHARMONIUM
FORBIDDEN TRANSITIONS
GAMMA RADIATION
PARTICLE DECAY
PHOTONS
RADIATIVE DECAY