Measurement of Associated Z + Charm Production in Proton–proton Collisions at \sqrt{s} = 8
Yükleniyor...
Tarih
2018
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Springer Link
Erişim Hakkı
Özet
A study of the associated production of a ZZ boson and a charm quark jet (Z+cZ+c), and a comparison to production with a bb quark jet (Z+bZ+b), in pppp collisions at a centre-of-mass energy of 8TeVTeV are presented. The analysis uses a data sample corresponding to an integrated luminosity of 19.7fb?1fb?1, collected with the CMS detector at the CERN LHC. The ZZ boson candidates are identified through their decays into pairs of electrons or muons. Jets originating from heavy flavour quarks are identified using semileptonic decays of cc or bb flavoured hadrons and hadronic decays of charm hadrons. The measurements are performed in the kinematic region with two leptons with p?T>20GeVpT?>20GeV, |??|<2.1|??|<2.1, 71<m??<111GeV71<m??<111GeV, and heavy flavour jets with pjetT>25GeVpTjet>25GeV and |?jet|<2.5|?jet|<2.5. The Z+cZ+c production cross section is measured to be ?(pp?Z+c+X)B(Z??+??)=8.8±0.5(stat)±0.6(syst)pb?(pp?Z+c+X)B(Z??+??)=8.8±0.5(stat)±0.6(syst)pb. The ratio of the Z+cZ+c and Z+bZ+b production cross sections is measured to be ?(pp?Z+c+X)/?(pp?Z+b+X)=2.0±0.2(stat)±0.2(syst)?(pp?Z+c+X)/?(pp?Z+b+X)=2.0±0.2(stat)±0.2(syst). The Z+cZ+cproduction cross section and the cross section ratio are also measured as a function of the transverse momentum of the ZZ boson and of the heavy flavour jet. The measurements are compared with theoretical predictions.
Açıklama
Anahtar Kelimeler
CMS, Physics, SMP, Vector boson, Heavy flavour, Standard model physics
Kaynak
WoS Q Değeri
Q1
