Observation of Three Upsilon States

Abstract

Three narrow resonances have been observed ine+e' annihilation into hadrons at total energies between 9.4 and 10.4 GeV. Measurements of mass spacings and ratios of lepton pair widths support the interpretation of these "T" states as the lowest triplet-5 levels of the bb quark-antiquark system. PACS numbers: 13.65.+iWe report here on the first results from the CLEO detector at the Cornell Electron Storage Ring (CESR). CLEO is a magnetic detector built around a 1.05-m-radius, 3-m-long solenoid coil producing a magnetic field parallel to the beams (see Fig. 1). Charged particles are observed and their momenta measured over a solid angle of 0.90 X47T sr in a cylindrical drift chamber occupying most of the field volume. A smaller cylindrical proportional chamber immediately surrounding the beam pipe provides improved resolution along the beam axis. Outside the 0.9-radiationlength thick aluminum solenoid coil are scintillation counters 2.2 m from the beam line (covering 1108

Beauty at High Precision / Sensitivity

“…A year after the discovery of ϒ, measurements of the ϒ(1S), ϒ(2S) leptonic widths at DORIS pinned down the charge of the new quark as Q b = − 1 3 [15]. Then, over the 1979-1980 end-of-year holidays, two experiments at the Cornell Electron Storage Ring announced that they had resolved three narrow ϒ states [16], confirming the suspicion raised by the discovery data from Fermilab (see Figure 2). VOLUME of the superior energy resolution of the CESR machine, our resonance peaks appear about two times higher and narrower than those observed at DORIS.…”

Beauty at High Precision / High Sensitivity [Slides]

“…A year after the discovery of ϒ, measurements of the ϒ(1S), ϒ(2S) leptonic widths at DORIS pinned down the charge of the new quark as Q b = − 1 3 [15]. Then, over the 1979-1980 end-of-year holidays, two experiments at the Cornell Electron Storage Ring announced that they had resolved three narrow ϒ states [16], confirming the suspicion raised by the discovery data from Fermilab (see Figure 2). VOLUME We fit the data by three very narrow resonances, each with a radiative tail convoluted with a Gaussian energy spread, added to a continuum.…”

“…The number of hadronic events, normalized to the small-~~pie Bhabha yield. The solid line indicates a fit described in the text.1113 Observation of three narrow ϒ levels by the CLEO and CUSB experiments at CESR, Ref [16]…”

First observation of the B$0\atop{s}$→K⁺K^- decay mode, and measurement of the B⁰ and $0\atop{s}$ mesons decay-rates into two-body charmless final states at CDF

“…The original enhancement was soon resolved into two resonances, Υ and Υ , and rapidly confirmed by the PLUTO and Double Arm Spectrometer II experiments at the DOppel RIng-Speicher e + e − storage ring (DORIS), which accurately determined the properties of the new resonances in 1978 [48]. Since 1980, further refinements of these measurements and discovery of new bound bb states were provided by the CLEO and the Columbia University-Stony Brook experiments at the Cornell Electron Storage Ring (CESR), and by the Crystal Ball detector at the upgraded DORIS ring [49]. In the 1980s, the experimental knowledge on the phenomenology of the b-quark increased considerably.…”