CESR shows bare‐bottomed mesons
DOI: 10.1063/1.2913785
In its first year of operation, the Cornell electron–positron storage ring, CESR, has provided strong evidence for the existence of a fifth quark flavor. The three narrow upsilon mesonic states near 10 GeV, first seen at Fermilab in 1977 and 1978, had offered the initial experimental evidence for a hadronic building block heavier than the charmed quark (see