Total Width and Leptonic Branching Ratio of theϒ(9.46)

Abstract

With use of the LENA detector at the DORIS e+e~ storage ring, the hadronic cross section and the ju-pair decay branching ratio of the T(9.46) resonance have been measured. r ee = 1.23±0.10 (±0.14) keV, B^ = [3.5±1A (±0.4)]%, and r tot = S5t\l (!?) keV have been obtained. The first set of errors gives the statistical uncertainty. The numbers in parentheses represent systematic errors arising from the uncertainty in the total hadronic cross section.PACS numbers: 13.20.Jf, 13.65.+iThe discovery of T(9.46) in proton-nucleus reactions 1 and its subsequent confirmation in e + e~ annihilations 2 ' 3 opened the study of a new family of particles. The properties of the members of this family provide a testing ground for the many models which have been used to describe the J/cp family. Of particular interest are the electronic and total widths (T ee and r tot ) for the T which can be obtained from the T hadronic cross section o h (T) and the leptonic branching ratio 5^. We present a measurement of B p|Lt which differs from zero by more than 2 standard deviations.The data were taken with the LENA (lead-glassNal) detector (Fig. 1) at the DORIS e + e~ storage ring. The LENA detector was constructed by the Deutsches Elektronen-Synchrotron (DESY)-Heidel- 92

Revisiting the heavy vector quarkonium leptonic widths *

“…[52], and gave 5.48 (16) keV , consistent with the experimental data. This indicates that the disagreement of our results with the experimental data may be due to the lack of QCD corrections.…”

“…The vector quarkonium leptonic decays have been studied since a long time [15][16][17][18][19][20][21]. With the progress in computer science and experimental technology, many advances have been reported in literature.…”