We have observed bottom-charm mesons via the decay mode Bc±→J/ψℓ±ν in 1.8 TeV pp̅ collisions using the CDF detector at the Fermilab Tevatron. A fit of background and signal contributions to the J/ψℓ mass distribution yielded 20.4-5.5+6.2 events from Bc mesons. A fit to the same distribution with background alone was rejected at the level of 4.8 standard deviations. We measured the Bc+ mass to be 6.40±0.39(stat)±0.13(syst)GeV/c2 and the Bc+ lifetime to be 0.46-0.16+0.18(stat)±0.03(syst) ps. Our measured yield (production cross section times branching ratio) for Bc+→J/ψℓ+ν relative to that for B+→J/ψK+ is 0.132-0.037+0.041(stat)±0.031(syst)-0.020+0.032(lifetime).
Observation of the Bc Meson in pp̅ Collisions at √s = 1.8 TeV
PAGLIARONE, Carmine Elvezio;
1998-01-01
Abstract
We have observed bottom-charm mesons via the decay mode Bc±→J/ψℓ±ν in 1.8 TeV pp̅ collisions using the CDF detector at the Fermilab Tevatron. A fit of background and signal contributions to the J/ψℓ mass distribution yielded 20.4-5.5+6.2 events from Bc mesons. A fit to the same distribution with background alone was rejected at the level of 4.8 standard deviations. We measured the Bc+ mass to be 6.40±0.39(stat)±0.13(syst)GeV/c2 and the Bc+ lifetime to be 0.46-0.16+0.18(stat)±0.03(syst) ps. Our measured yield (production cross section times branching ratio) for Bc+→J/ψℓ+ν relative to that for B+→J/ψK+ is 0.132-0.037+0.041(stat)±0.031(syst)-0.020+0.032(lifetime).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
