{"doi":"10.2172/1453988","title":"Charmonium Spectroscopy from Radiative Decays of the J/ψ and ψ'","abstract":"Data were collected at the Stanford Linear Accelerator Center's electron-positron colliding beam machine, SPEAR, intermittently over a two and half year period, beginning at the end of 1978. The Crystal Ball detector consists of a highly segmented array of 732 NaI(Tl) crystals (16 radiation lengths) covering ≅ 98% of 4π steradians, and is used to measure the photon energies, directions, and lateral shower distributions. Centrally located spark and proportional chambers are used for charged particle recognition. as a result, this detector is excellently suited for studying the radiative transitions among the charmonium family of states: i) from ψ' to the triplet P states, x(3415), x(3510), and x(3550); ii) from ψ' and J/ψ to the singlet S state n<sub>c</sub>(2984); and iii) from ψ' to the radially excited singlet S state n<sub>c</sub>'(3592). The analysis of 1.8 ∙ 10<sup>6</sup> ψ' and 2.2 ∙ 10<sup>6</sup> J/ψ decays yields the following spectrum of states: x<sub>0</sub>(3418), x<sub>1</sub>(3512), x<sub>2</sub>3558), n<sub>c</sub>(2984), and n<sub>c</sub>'(3592), each with a ± 4 MeV error on its mass. The branching ratios are measured to be: B(ψ'→yx<sub>0,1,2</sub>) = (9.9 ± 0.5 ± 0.8)%, (9.0 ± 0.5 ± 0.7)%, and (8.0 ± 0.5 ± 0.7)%, respectively; B(ψ'→yn<sub>c</sub>) = (0.28 ± 0.06)% and B(J/ψ→yn<sub>c</sub>) = (1.27 ± 0.36)%; and B(ψ'→yn<sub>c</sub>) = (0.5 - 1.2)% at the 90% confidence level. Values for the natural line widths are obtained: Γ(x<sub>0,1,2</sub>) = (13.5 - 20.4) MeV, < 3.8 MeV, (0.85 - 4.9) MeV, respectively (90% C.L.); Γ(n<sub>c</sub>) = (11.5 + 4.5/ - 4.0) MeV; and Γ(n<sub>c</sub>') < 7 MeV (90% C.L.). The cascade product branching ratios B(ψ'→yx<sub>J</sub>) ∙ B(x<sub>J</sub> → yJ/ψ) were measured for J = 1 and 2 to be: (2.56 ± 0.12 ± 0.20)% and (0.99 ± 0.10 ± 0.08)% respectively. No signal was seen for the J= 0 transition, with an upper limit above its previously measured product branching ratio. The results of this analysis are compared with the predictions of the charmonium models.","journal":"OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information)","year":1982,"id":11513,"datarank":0.6766289259775276,"base_score":4.51085950651685,"endowment":4.51085950651685,"self_citation_contribution":0.6766289259775276,"citation_network_contribution":0.0,"self_endowment_contribution":0.6766289259775276,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":90,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.4288,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"1982-08-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":92130,"name":"J. Gaiser","orcid":null,"position":1,"is_corresponding":false},{"id":92129,"name":"John Gaiser","orcid":null,"position":0,"is_corresponding":true}],"reference_count":4,"raw_metadata":null,"created_at":"2026-03-01T18:20:47.508186Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}