#### ${{\mathit t}}$ -Quark Electric Charge

VALUE DOCUMENT ID TECN  COMMENT
$0.64$ $\pm0.02$ $\pm0.08$ 1
 2013 AY
ATLS ${{\mathit \ell}}$ +$\not E_T+{}\geq{}$4 jets (${}\geq{}$1 ${{\mathit b}}$ )
• • We do not use the following data for averages, fits, limits, etc. • •
2
 2014 D
D0 ${{\mathit \ell}}$ +$\not E_T+{}\geq{}$4 jets (${}\geq{}$2 ${{\mathit b}}$ )
3
 2013 J
CDF ${{\mathit p}}{{\overline{\mathit p}}}$ at 1.96 TeV
4
 2010 S
CDF Repl. by AALTONEN 2013J
5
 2007 C
D0 fraction of $\vert$q$\vert$=4e/3 pair
 1 AAD 2013AY result is based on 2.05 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ data at $\sqrt {s }$ = 7 TeV, the result is obtained by reconstructing ${{\mathit t}}{{\overline{\mathit t}}}$ events in the lepton + jets final state, where ${{\mathit b}}$ -jet charges are tagged by the jet-charge algorithm. This measurement excludes the charge $-4$/3 assignment to the top quark at more than 8 standard deviations.
 2 ABAZOV 2014D result is based on 5.3 fb${}^{-1}$ of ${{\mathit p}}{{\overline{\mathit p}}}$ data at $\sqrt {s }$=1.96 TeV. The electric charge of system in ${{\mathit t}}{{\overline{\mathit t}}}$ candidate events is measured from the charges of the leptons from ${{\mathit W}}$ decay and in ${{\mathit b}}$ jets. Under the assumption that the system consists of the sum of the top quark and the charge $-4$/3 quark ${{\mathit b}^{\,'}}$ (-4/3) of the same mass, the top quark fraction is found to be ${{\mathit f}}$ = $0.88$ $\pm0.13$ (stat)$\pm0.11$ (syst), or the upper bound for the ${{\mathit b}^{\,'}}$ (-4/3) contamination of 1 $−$ ${{\mathit f}}$ $<$ 0.46 (95$\%$ CL).
 3 AALTONEN 2013J excludes the charge $-4$/3 assignment to the top quark at 99$\%$ CL, using 5.6 fb${}^{-1}$ of data in ${{\mathit p}}{{\overline{\mathit p}}}$ collisions at $\sqrt {s }$ = 1.96 TeV. Result is obtained by reconstructing ${{\mathit t}}{{\overline{\mathit t}}}$ events in the lepton + jets final state, where ${{\mathit b}}$ -jet charges are tagged by the jet-charge algorithm.
 4 AALTONEN 2010S excludes the charge $-4$/3 assignment for the top quark [CHANG 1999 ] at 95$\%$CL, using 2.7 fb${}^{-1}$ of data in ${{\mathit p}}{{\overline{\mathit p}}}$ collisions at $\sqrt {s }$ = 1.96 TeV. Result is obtained by reconstructing ${{\mathit t}}{{\overline{\mathit t}}}$ events in the lepton + jets final state, where ${{\mathit b}}$ -jet charges are tagged by the SLT (soft lepton tag) algorithm.
 5 ABAZOV 2007C reports an upper limit $\rho <$ 0.80 (90$\%$ CL) on the fraction $\rho$ of exotic quark pairs ${{\mathit Q}}{{\overline{\mathit Q}}}$ with electric charge $\vert$q$\vert$ = 4e/3 in ${{\mathit t}}{{\overline{\mathit t}}}$ candidate events with high $p_T$ lepton, missing $\mathit E_{T}$ and ${}\geq{}$4 jets. The result is obtained by measuring the fraction of events in which the quark pair decays into ${{\mathit W}^{-}}$ + ${{\mathit b}}$ and ${{\mathit W}^{+}}$ + ${{\overline{\mathit b}}}$ , where ${{\mathit b}}$ and ${{\overline{\mathit b}}}$ jets are discriminated by using the charge and momenta of tracks within the jet cones. The maximum CL at which the model of CHANG 1999 can be excluded is 92$\%$. Based on 370 pb${}^{-1}$ of data at $\sqrt {s }$ = 1.96 TeV.
References:
 ABAZOV 2014D
PR D90 051101 Measurement of the Electric Charge of the Top Quark in ${\mathit {\mathit t}}{\mathit {\overline{\mathit t}}}$ Events
JHEP 1311 031 Measurement of the Top Quark Charge in ${{\mathit p}}{{\mathit p}}$ Collisions at $\sqrt {s }$ = 7 TeV with the ATLAS Detector
PR D88 032003 Exclusion of Exotic Top-Like Quarks with -4/3 Electric Charge using Jet-Charge Tagging in Single-Lepton ${\mathit {\mathit t}}{\mathit {\overline{\mathit t}}}$ Events at CDF
PRL 98 041801 Experimental Discrimination between Charge 2$\mathit e$/3 Top Quark and Charge 4$\mathit e$/3 Exotic Quark Production Scenarios