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| CMS-EWK-11-004 ; CERN-PH-EP-2012-187 | ||
| Forward-backward asymmetry of Drell-Yan lepton pairs in pp collisions at $\sqrt{s}$ = 7 TeV | ||
| CMS Collaboration | ||
| 17 July 2012 | ||
| Phys. Lett. B 718 (2013) 752-772 | ||
| Abstract: A measurement of the forward-backward asymmetry ($A_{FB}$) of Drell-Yan lepton pairs in pp collisions at $\sqrt{s}$ = 7 TeV is presented. The data sample, collected with the CMS detector, corresponds to an integrated luminosity of 5 inverse femtobarns. The asymmetry is measured as a function of dilepton mass and rapidity in the dielectron and dimuon channels. Combined results from the two channels are also presented. The ($A_{FB}$) measurement in the dimuon channel and the combination of the two channels are the first such results obtained at a hadron collider. The measured asymmetries are consistent with the standard model predictions. | ||
| Links: e-print arXiv:1207.3973 [hep-ex] (PDF) ; CDS record ; inSPIRE record ; Public twiki page ; Rivet record ; HepData record ; CADI line (restricted) ; | ||
| Figures | |
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Figure 1:
The unfolded $ {{\mu ^+}} {{\mu ^-}}$ and $ {\mathrm {e}^+} {\mathrm {e}^-}$ measurements of $A_\mathrm {FB}$ at the Born level in four $|y|$ bins for $ {p_{\mathrm {T}}} (\ell ) >$ 20 GeV and $|\eta (\ell )| <$ 2.4. The data points are shown with statistical error bars. |
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Figure 2:
The unfolded and combined ($ {{\mu ^+}} {{\mu ^-}}$ and $ {\mathrm {e}^+} {\mathrm {e}^-}$) measurement of $A_\mathrm {FB}$ at the Born level in four $|y|$ bins for $ {p_{\mathrm {T}}} (\ell ) > $ 20 GeV and $|\eta (\ell )| <$ 2.4. The data points are shown with both statistical error bars and combined statistical and systematic error bars. The error bars on the MC points represent the quadratically summed PDF uncertainties and statistical errors. The horizontal extent of the error bars indicates the bin width (except for the last bin, which is truncated at 400 GeV). Beneath each plot is shown the difference between data and MC, normalized by the combined statistical and systematic uncertainty. The green and yellow bands indicate the $1\sigma $ and $2\sigma $ differences of data from theory predictions. |
| Tables | |
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Table 1:
Unfolded combined measurements of $A_{\mathrm{FB}}$ in each $M$-$|y|$ bin. The average mass in each bin is shown, together with the measured $A_{\mathrm{FB}}$ and the corresponding statistical, systematic, and total uncertainties. The statistical and systematic errors are combined in quadrature to obtain the total uncertainties. The $A_{\mathrm{FB}}$ values estimated from MC are also shown, with the corresponding statistical and PDF uncertainties. The final column shows the larger of the differences $A_{\mathrm{FB}} \text{(Born)} - A_{\mathrm{FB}} \text{(raw)}$ in the muon and electron channels. |
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Table 2:
Estimated systematic uncertainties on $A_{\mathrm{FB}}$, in units of $10^{-3}$, for each rapidity bin, in the mass bin around the Z peak, $M =$ 86-96 GeV. The components are discussed in the text. |
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Compact Muon Solenoid LHC, CERN |
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