pdgLive

${{\mathit t}}{{\overline{\mathit t}}}$ Production Cross Section in ${{\mathit p}}{{\mathit p}}$ Collisions at $\sqrt {s }$ = 7 TeV

Unless otherwise noted the first quoted error is from statistics, the second from systematic uncertainties, and the third from luminosity. If only two errors are quoted the luminosity is included in the systematic uncertainties.

VALUE (pb)

DOCUMENT ID

TECN

COMMENT

• • We do not use the following data for averages, fits, limits, etc. • •

$168.5$ $\pm0.7$ ${}^{+6.2}_{-5.9}$ ${}^{+3.4}_{-3.2}$

ATLS

1${{\mathit \ell}}+\not E_T+{}\geq{}$3j (0,1,2 ${{\mathit b}}$-tagged j)

$178.5$ $\pm4.7$

LHC

${{\mathit e}^{\pm}}{{\mathit \mu}^{\mp}}$ pair; ATLAS+CMS combined

$161.7$ $\pm6.0$ $\pm12.0$ $\pm3.6$

CMS

${{\mathit \ell}}+\not E_T+{}\geq{}$4j (${}\geq{}1{{\mathit b}}$)

$173.6$ $\pm2.1$ ${}^{+4.5}_{-4.0}$ $\pm3.8$

CMS

${{\mathit e}}$ + ${{\mathit \mu}}$ + $\not E_T$ + ${}\geq{}$0j

$181.2$ $\pm2.8$ ${}^{+10.8}_{-10.6}$

ATLS

${{\mathit e}}$ + ${{\mathit \mu}}$ + $\not E_T$ + ${}\geq{}$0j

$178$ $\pm3$ $\pm16$ $\pm3$

ATLS

${{\mathit \ell}}$+jets, ${{\mathit \ell}}{{\mathit \ell}}$+jets, ${{\mathit \ell}}{{\mathit \tau}_{{{h}}}}$+jets

LHCB

${{\mathit \mu}}+{}\geq{}$1j(${{\mathit b}}$-tag) forward region

$182.9$ $\pm3.1$ $\pm6.4$

ATLS

${{\mathit e}}$ + ${{\mathit \mu}}$ + 1 or 2${{\mathit b}}$ jets

$194$ $\pm18$ $\pm46$

ATLS

${{\mathit \tau}_{{{h}}}}$ + $\not E_T$ + ${}\geq{}$5j (${}\geq{}2{{\mathit b}}$)

$139$ $\pm10$ $\pm26$

CMS

${}\geq{}$6 jets with 2 b-tags

$158.1$ $\pm2.1$ $\pm10.8$

CMS

${{\mathit \ell}}$ + $\not E_T$ + jets(${}\geq{}$1 b-tag)

$152$ $\pm12$ $\pm32$

CMS

${{\mathit \tau}_{{{h}}}}$+ $\not E_T$+ ${}\geq{}$4 jets (${}\geq{}$1 b)

$177$ $\pm20$ $\pm14$ $\pm7$

ATLS

Repl. by AAD 2012BF

$176$ $\pm5$ ${}^{+14}_{-11}$ $\pm8$

ATLS

${{\mathit \ell}}{{\mathit \ell}}+\not E_T+{}\geq{}$2j

$187$ $\pm11$ ${}^{+18}_{-17}$ $\pm6$

ATLS

${{\mathit \ell}}$ + $\not E_T$ + ${}\geq{}$ 3j with ${{\mathit b}}$-tag

$186$ $\pm13$ $\pm20$ $\pm7$

ATLS

${{\mathit \ell}}$ + ${{\mathit \tau}_{{{h}}}}$+ $\not E_T+{}\geq{}$2j (${}\geq{}1{{\mathit b}}$)

$143$ $\pm14$ $\pm22$ $\pm3$

CMS

${{\mathit \ell}}$ + ${{\mathit \tau}_{{{h}}}}$+ $\not E_T+{}\geq{}$2j (${}\geq{}1{{\mathit b}}$)

$161.9$ $\pm2.5$ ${}^{+5.1}_{-5.0}$ $\pm3.6$

CMS

${{\mathit \ell}}{{\mathit \ell}}$ + $\not E_T$ + ${}\geq{}$ 2${{\mathit b}}$

$145$ $\pm31$ ${}^{+42}_{-27}$

ATLS

${{\mathit \ell}}+\not E_T+{}\geq{}$4j, ${{\mathit \ell}}{{\mathit \ell}}+\not E_T+{}\geq{}$2j

$173$ ${}^{+39}_{-32}$ $\pm7$

CMS

${{\mathit \ell}}$ + $\not E_T$ + ${}\geq{}$3 jets

$168$ $\pm18$ $\pm14$ $\pm7$

CMS

${{\mathit \ell}}{{\mathit \ell}}$ + $\not E_T$ + jets

$154$ $\pm17$ $\pm6$

CMS

Combination

$194$ $\pm72$ $\pm24$ $\pm21$

CMS

${{\mathit \ell}}{{\mathit \ell}}$ + $\not E_T$ + ${}\geq{}$2 jets

¹

AABOUD 2023 based on 4.6 fb${}^{-1}$ of data. The measurement is performed using a multi-variate event classifier based on a binary learning algorithm which differentiates ${{\mathit t}}{{\overline{\mathit t}}}$ events from backgrounds in a three-dimensional space. The result is in agreement with the NNLO+NNLL SM prediction of $177$ ${}^{+5}_{-6}$(scale)$\pm9(PDF+\alpha _{s}$) pb for ${\mathit m}_{{{\mathit t}}}$ = 172.5 GeV. Compared to the measured cross section using the dilepton mode of AAD 2014AY, significance of discrepancy is between 1.9$\sigma $ to 2.1$\sigma $.

²

AAD 2023AY based on 5 fb${}^{-1}$ of data using ${\mathit m}_{{{\mathit t}}}$ = 172.5 GeV. The ratio of the combined cross section at $\sqrt {s }$ = 8 TeV to this one at $\sqrt {s }$ = 7 TeV is determined as $1.363$ $\pm0.032$. The values of the cross sections as well as the ratio are consistent with the NNLO+NNLL SM predictions.

³

KHACHATRYAN 2017B based on 5.0 fb${}^{-1}$ of data, using a binned likelihood fit of templates to the data. Also the ratio ${\mathit \sigma (}{{\mathit t}}{{\overline{\mathit t}}}$; 8 TeV${)}/{\mathit \sigma (}{{\mathit t}}{{\overline{\mathit t}}}$; 7 TeV${)}$ = $1.43$ $\pm0.04$ $\pm0.07$ $\pm0.05$ is reported. The results are in agreement with NNLO SM predictions.

⁴	KHACHATRYAN 2016AW based on 5.0 fb${}^{-1}$ of data, using a binned likelihood fit to differential distributions of ${{\mathit b}}$-tagged and non-${{\mathit b}}$-tagged jets. The result is in good agreement with NNLO SM predictions.

⁵

Based on 4.6 fb${}^{-1}$ of data. Uses a template fit to distributions of $\not E_T$ and jet multiplicities to measure simultaneously ${{\mathit t}}{{\overline{\mathit t}}}$, ${{\mathit W}}{{\mathit W}}$, and ${{\mathit Z}}$/ ${{\mathit \gamma}^{*}}$ $\rightarrow$ ${{\mathit \tau}}{{\mathit \tau}}$ cross sections, assuming ${\mathit m}_{{{\mathit t}}}$ = 172.5 GeV.

⁶	AAD 2015CC based on 4.6 fb${}^{-1}$ of data. The event selection criteria are optimized for the ${{\mathit \ell}}{{\mathit \tau}_{{{h}}}}$ + jets channel. Using only this channel $183$ $\pm9$ $\pm23$ $\pm3$ pb is derived for the cross section.

⁷

AAIJ 2015R, based on 1.0 fb${}^{-1}$ of data, reports $0.239$ $\pm0.053$ $\pm0.033$ $\pm0.024$ pb cross section for the forward fiducial region ${{\mathit p}_{{{T}}}}({{\mathit \mu}}$) $>$ 25 GeV, 2.0 $<$ ${{\mathit \eta}}({{\mathit \mu}}$) $<$ 4.5, 50 GeV $<$ ${{\mathit p}_{{{T}}}}({{\mathit b}}$) $<$ 100 GeV, 2.2 $<$ ${{\mathit \eta}}({{\mathit b}}$) $<$ 4.2, ${{\mathit \Delta}}{{\mathit R}}({{\mathit \mu}},{{\mathit b}}$) $>$ 0.5, and ${{\mathit p}_{{{T}}}}({{\mathit \mu}}+{{\mathit b}}$) $>$ 20 GeV. The three errors are from statistics, systematics, and theory. The result agrees with the SM NLO prediction.

⁸

AAD 2014AY reports $182.9$ $\pm3.1$ $\pm4.2$ $\pm3.6$ $\pm3.3$ pb value based on 4.6 fb${}^{-1}$ of data. The four errors are from statistics, systematic, luminosity, and the 0.66$\%$ beam energy uncertainty. We have combined the systematic uncertainties in quadrature. The result is for ${\mathit m}_{{{\mathit t}}}$ = 172.5GeV; for other ${\mathit m}_{{{\mathit t}}}$, ${\mathit \sigma (}{\mathit m}_{{{\mathit t}}}{)}$ = $\sigma $(172.5GeV)${\times }[1-0.0028{\times }({\mathit m}_{{{\mathit t}}}-172.5$GeV)]. The result is consistent with the SM prediction at NNLO.

⁹	Based on 1.67 fb${}^{-1}$ of data. The result uses the acceptance for ${\mathit m}_{{{\mathit t}}}$ = 172.5 GeV.

¹⁰	Based on 3.54 fb${}^{-1}$ of data.

¹¹	Based on 2.3 fb${}^{-1}$ of data.

¹²	Based on 3.9 fb${}^{-1}$ of data.

¹³	Based on 35 pb${}^{-1}$ of data for an assumed top quark mass of ${\mathit m}_{{{\mathit t}}}$ = 172.5 GeV.

¹⁴	Based on 0.70 fb${}^{-1}$ of data. The 3 errors are from statistics, systematics, and luminosity. The result uses the acceptance for ${\mathit m}_{{{\mathit t}}}$ = 172.5 GeV.

¹⁵	Based on 35 pb${}^{-1}$ of data. The 3 errors are from statistics, systematics, and luminosity. The result uses the acceptance for ${\mathit m}_{{{\mathit t}}}$ = 172.5 GeV and $173$ $\pm17$ ${}^{+18}_{-16}$ $\pm6$ pb is found without the ${{\mathit b}}$-tag.

¹⁶	Based on 2.05 fb${}^{-1}$ of data. The hadronic ${{\mathit \tau}}$ candidates are selected using a BDT technique. The 3 errors are from statistics, systematics, and luminosity. The result uses the acceptance for ${\mathit m}_{{{\mathit t}}}$ = 172.5 GeV.

¹⁷	Based on 2.0 fb${}^{-1}$ and 2.2 fb${}^{-1}$ of data for ${{\mathit \ell}}$ = ${{\mathit e}}$ and ${{\mathit \ell}}$ = ${{\mathit \mu}}$, respectively. The 3 errors are from statistics, systematics, and luminosity. The result uses the acceptance for ${\mathit m}_{{{\mathit t}}}$ = 172.5 GeV.

¹⁸	Based on 2.3 fb${}^{-1}$ of data. The 3 errors are from statistics, systematics, and luminosity. The result uses the profile likelihood-ratio (PLB) method and an assumed ${\mathit m}_{{{\mathit t}}}$ of 172.5 GeV.

¹⁹	Based on 2.9 pb${}^{-1}$ of data. The result for single lepton channels is $142$ $\pm34$ ${}^{+50}_{-31}$ pb, while for the dilepton channels is $151$ ${}^{+78}_{-62}{}^{+37}_{-24}$ pb.

²⁰	Result is based on 36 pb${}^{-1}$ of data. The first uncertainty corresponds to the statistical and systematic uncertainties, and the second corresponds to the luminosity.

²¹

Based on 36 pb${}^{-1}$ of data. The ratio of ${{\mathit t}}{{\overline{\mathit t}}}$ and ${{\mathit Z}}/{{\mathit \gamma}^{*}}$ cross sections is measured as ${\mathit \sigma (}$ ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit t}}{{\overline{\mathit t}}}{)}/{\mathit \sigma (}$ ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit Z}}$/ ${{\mathit \gamma}^{*}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}/{{\mathit \mu}^{+}}{{\mathit \mu}^{-}}{)}$ = $0.175$ $\pm0.018$(stat)$\pm0.015$(syst) for 60 $<$ ${\mathit m}_{\mathrm {{{\mathit \ell}} {{\mathit \ell}}}}<$ 120 GeV, for which they use an NNLO prediction for the denominator cross section of $972$ $\pm42$ pb.

²²

Result is based on 36 pb${}^{-1}$ of data. The first error is from statistical and systematic uncertainties, and the second from luminosity. This is a combination of a measurement in the dilepton channel (CHATRCHYAN 2011F) and the measurement in the ${{\mathit \ell}}$ + jets channel (CHATRCHYAN 2011Z) which yields $150$ $\pm9$ $\pm17$ $\pm6$ pb.

²³	Result is based on $3.1$ $\pm0.3$ pb${}^{-1}$ of data.

Except where otherwise noted, content of the 2024 Review of Particle Physics is licensed under a Creative Commons Attribution 4.0 International (CC BY 4.0) license. The publication of the Review of Particle Physics is supported by US DOE, MEXT (Japan), INFN (Italy) and CERN. Individual collaborators receive support for their PDG activities from their respective institutes or funding agencies. © 2024. See LBNL disclaimers.