Observation of the Z→ψℓ+ℓ− Decay in pp Collisions at √s=13  TeV; Physical Review Letters; Vol. 121, iss. 14

Observation of the Z→ψℓ+ℓ− Decay in pp Collisions at √s=13  TeV; Physical Review Letters; Vol. 121, iss. 14

Dettagli Bibliografici
Parent link:Physical Review Letters
Vol. 121, iss. 14.— 2018.— [141801, 17 p.]
Ente Autore: Национальный исследовательский Томский политехнический университет Исследовательская школа физики высокоэнергетических процессов
Altri autori: Sirunyan A. M., Tumasyan A. R., Adam W. Wolfgang, Ambrogi F. Federico, Asilar E. Ece, Bergauer T. Thomas, Babaev A. A. Anton Anatoljevich, Baydali S. A. Sergey Anatolievich
Riassunto:Title screen
This Letter presents the observation of the rare Z boson decay Z→ψℓ+ℓ−. Here, ψ represents contributions from direct J/ψ and ψ(2S)→J/ψX, ℓ+ℓ− is a pair of electrons or muons, and the J/ψ meson is detected via its decay to μ+μ−. The sample of proton-proton collision data, collected by the CMS experiment at the LHC at a center-of-mass energy of 13 TeV, corresponds to an integrated luminosity of 35.9  fb−1. The signal is observed with a significance in excess of 5 standard deviations. After subtraction of the ψ(2S)→J/ψX contribution, the ratio of the branching fraction of the exclusive decay Z→J/ψℓ+ℓ− to the decay Z→μ+μ−μ+μ− within a fiducial phase space is measured to be B(Z→J/ψℓ+ℓ−)/B(Z→μ+μ−μ+μ−)=0.67±0.18(stat)±0.05(syst).
Режим доступа: по договору с организацией-держателем ресурса
Lingua:inglese
Pubblicazione: 2018
Soggetti:
электронный ресурс
труды учёных ТПУ
распад
наблюдение
Accesso online:https://doi.org/10.1103/PhysRevLett.121.141801
Natura: Elettronico Capitolo di libro
KOHA link:https://koha.lib.tpu.ru/cgi-bin/koha/opac-detail.pl?biblionumber=661255

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