Abstract
The production of $t\overline{t}$, $W+b\overline{b}$ and $W+c\overline{c}$ is studied in the forward region of proton-proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98 $\pm$ 0.02 $\mbox{fb}^{-1}$. The $W$ bosons are reconstructed in the decays $W\rightarrow\ell\nu$, where $\ell$ denotes muon or electron, while the $b$ and $c$ quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions.
Highlights
The production of tt pairs from proton–proton collisions in the forward region is of considerable interest, as it may be sensitive to physics beyond the Standard Model (SM) [1]
Backgrounds from misidentified leptons or semileptonic decays of heavy-flavour hadrons are suppressed by two requirements applied to the lepton: impact parameter (IP)( ) must be less than 0.04 mm and pT( )/pT(j ) > 0.8, where j is defined as a reconstructed jet with relaxed quality criteria that contains the lepton
The QCD multi-jet background normalisation is adjusted in order to describe the event yield at IP( ) > 0.04 mm, after subtracting the non-QCD backgrounds obtained from simulation
Summary
The production of tt pairs from proton–proton (pp) collisions in the forward region is of considerable interest, as it may be sensitive to physics beyond the Standard Model (SM) [1]. LHCb has measured top quark production in the forward region in the W + b final state [6]. The W → eν candidates are required to satisfy the hardware trigger requirement for electrons of having an electromagnetic cluster of high transverse energy associated with signals in the PRS and SPD detectors, and the software trigger, which selects events with an. Since neither showering nor hadronisation are included in MCFM, an overall correction is calculated to compare the measurements with the predicted cross-section at particlelevel This is done by generating W + bb, W + cc and tt events with Pythia 8 with the CT10 PDF set [21] where the same acceptance requirements are applied. The particle-level lepton momentum used here is the momentum after final-state radiation as implemented in Pythia 8
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
