# Abstract

A search for single top quark production through flavor-changing neutral currents in the anomalous tqγ vertex is presented in proton-proton collisions at a center-of-mass energy of 8 TeV. The analysis is based on a data-set corresponding to an integrated luminosity of 19.1 fb−1 collected with the CMS detector. The search is performed on events with one isolated muon and jets in the final state. No evidence for a signal is observed. Upper limits on the strengths of the anomalous couplings at leading order for vertices involving a top quark, a photon, and another up-like quark are set at 95% confidence level to be $\kappa_{tu\gamma}$<0.028 and $\kappa_{tc\gamma}$<0.094. The corresponding upper bounds on the top quark decay branching ratios are $BR(t\rightarrow u+\gamma)$<0.0161% and $BR(t\rightarrow c+\gamma)$<0.182%.

# Public Document

The document CMS-PAS-TOP-14-003 can be found on the CERN Document Server, here.

# Control plots and BDT distributions

 The BDT output distribution for data, all backgrounds, and tγu. The Wγ+jets and W+jets contributions are estimated from data. The tuγ signal sample are normalized to a cross section of 1 pb. The uncertainty band includes both the statistical and systematic uncertainties. The statistical part is the dominant contribution. The BDT output distribution for data, all backgrounds, and tγc. The Wγ+jets and W+jets contributions are estimated from data. The tcγ signal sample are normalized to a cross section of 1 pb.The uncertainty band includes both the statistical and systematic uncertainties. The statistical part is the dominant contribution. Distributions of of the photon after the final event selection and background estimations. The band includes both statistical and systematic uncertainties and it is dominated by the statistical uncertainty. Distributions of η of the photon after the final event selection and background estimations. The band includes both statistical and systematic uncertainties and it is dominated by the statistical uncertainty. Distributions of muon after the final event selection and background estimations. The band includes both statistical and systematic uncertainties and it is dominated by the statistical uncertainty. Distributions of muon η after the final event selection and background estimations. The band includes both statistical and systematic uncertainties and it is dominated by the statistical uncertainty. Distributions of b-jet after the final event selection and background estimations. The band includes both statistical and systematic uncertainties and it is dominated by the statistical uncertainty. Distributions of b-jet η after the final event selection and background estimations. The band includes both statistical and systematic uncertainties and it is dominated by the statistical uncertainty.

 Distributions of $\Delta$R(μ, γ) after the final event selection and background estimations. The uncertainty band includes both the statistical and systematic uncertainties. The statistical part is the dominant contribution. Distributions of $\Delta$ R(b − jet, γ) after the final event selection and background estimations. The band includes both statistical and systematic uncertainties and it is dominated by the statistical uncertainty. Distributions of cos(W, γ) after the final event selection and background estimations. The band includes both statistical and systematic uncertainties and it is dominated by the statistical uncertainty. Distributions of cos(top, γ) after the final event selection and background estimations. The band includes both statistical and systematic uncertainties and it is dominated by the statistical uncertainty. Distributions of jet multiplicity after the final event selection and background estimations. The band includes both statistical and systematic uncertainties and it is dominated by the statistical uncertainty Distributions of b-tagging discriminator after the final event selection and background estimations. The band includes both statistical and systematic uncertainties and it is dominated by the statistical uncertainty.

# Exclusion plots

 The 95% C.L. upper limit on the $tu\gamma$ signal cross section as a function of $\kappa_{tu\gamma}$, as well as the predicted cross section calculated by Protos The 95% C.L. upper limit on the $tc\gamma$ signal cross section as a function of $\kappa_{tc\gamma}$, as well as the predicted cross section calculated by Protos

# Results

The observed and expected 95% exclusion limits on the signal cross section, anomalous couplings, and branching ratios with and without including the QCD higher order corrections on the signal cross section. PNG

# Comparison plots

 The observed 95% C.L. upper limit on the $BR(t\rightarrow u+\gamma)$ versus the strength of the anomalous coupling $\kappa_{tu\gamma}$ for the DELPHI, ZEUS, H1, CDF and CMS collaborations. The observed 95% C.L. upper limit on the $BR(t\rightarrow u+\gamma)$ versus $BR(t\rightarrow u+Z)$ for the DELPHI, ZEUS, H1, DØ, CDF, ATLAS and CMS collaborations.

Topic attachments
I Attachment History Action Size Date Who Comment
pdf BR_BR.pdf r1 manage 14.9 K 2014-05-10 - 11:10 RezaGoldouzian tz tgamma comparison plots
png BR_BR.png r1 manage 21.1 K 2014-05-11 - 11:52 RezaGoldouzian tz tgamma comparison plots
pdf CSV.pdf r1 manage 17.2 K 2014-05-10 - 10:04 RezaGoldouzian distribution of CSV discriminator
png CSV.png r1 manage 31.8 K 2014-05-11 - 10:41 RezaGoldouzian distribution of CSV discriminator
pdf costopgamma.pdf r1 manage 18.8 K 2014-05-10 - 10:04 RezaGoldouzian distribution of cos(top,gamma)
png costopgamma.png r1 manage 35.2 K 2014-05-11 - 11:04 RezaGoldouzian distribution of cos(top,gamma)
pdf deltarphotonjetpdf.pdf r1 manage 16.1 K 2014-05-10 - 10:06 RezaGoldouzian distribution of deltaR(gamma,bjet)
png deltarphotonjetpdf.png r1 manage 29.2 K 2014-05-11 - 11:05 RezaGoldouzian distribution of deltaR(gamma,bjet)
pdf deltarphotonmuonpdf.pdf r1 manage 16.1 K 2014-05-10 - 10:07 RezaGoldouzian distribution of deltaR(gamma,muon)
png deltarphotonmuonpdf.png r1 manage 28.9 K 2014-05-11 - 11:05 RezaGoldouzian distribution of deltaR(gamma,muon)
pdf etajetpdf.pdf r1 manage 16.7 K 2014-05-10 - 09:56 RezaGoldouzian distribution of b-jet eta
png etajetpdf.png r1 manage 28.2 K 2014-05-11 - 10:03 RezaGoldouzian distribution of b-jet eta
pdf etamuonpdf.pdf r1 manage 16.5 K 2014-05-10 - 09:35 RezaGoldouzian distribution of b-jet eta
png etamuonpdf.png r1 manage 28.9 K 2014-05-11 - 10:03 RezaGoldouzian distribution of muon eta
pdf jetmulti.pdf r1 manage 16.0 K 2014-05-10 - 10:07 RezaGoldouzian jet multiplicity
png jetmulti.png r1 manage 29.4 K 2014-05-11 - 11:06 RezaGoldouzian jet multiplicity
pdf kappa_BR.pdf r1 manage 15.0 K 2014-05-10 - 11:11 RezaGoldouzian kappa BR comparison plots
png kappa_BR.png r1 manage 18.5 K 2014-05-11 - 11:52 RezaGoldouzian kappa BR comparison plots
png limitResults.png r1 manage 63.2 K 2014-05-10 - 19:30 RezaGoldouzian upper limit results
pdf newcoswgamma.pdf r1 manage 18.7 K 2014-05-10 - 10:03 RezaGoldouzian distribution of cos(W,gamma)
png newcoswgamma.png r1 manage 34.3 K 2014-05-11 - 11:07 RezaGoldouzian distribution of cos(W,gamma)
pdf newetaphpton.pdf r1 manage 16.6 K 2014-05-10 - 09:29 RezaGoldouzian distribution of photon eta
png newetaphpton.png r1 manage 29.0 K 2014-05-11 - 10:02 RezaGoldouzian distribution of photon eta
pdf newptphoton.pdf r1 manage 17.7 K 2014-05-10 - 09:23 RezaGoldouzian distribution of photon Pt
png newptphoton.png r1 manage 30.6 K 2014-05-11 - 10:02 RezaGoldouzian distribution of photon Pt
pdf ptjetpdf.pdf r1 manage 17.5 K 2014-05-10 - 09:37 RezaGoldouzian distribution of b-jet pt
png ptjetpdf.png r1 manage 32.3 K 2014-05-11 - 10:04 RezaGoldouzian distribution of b-jet pt
pdf ptmuonpdf.pdf r1 manage 16.9 K 2014-05-10 - 09:38 RezaGoldouzian distribution of muon pt
png ptmuonpdf.png r1 manage 31.2 K 2014-05-11 - 10:04 RezaGoldouzian distribution of muon pt
pdf tGclimit.pdf r1 manage 15.5 K 2014-05-10 - 10:47 RezaGoldouzian exclusion plot tgammac
png tGclimit.png r1 manage 29.3 K 2014-05-11 - 11:43 RezaGoldouzian exclusion plot tgammac
pdf tGulimit.pdf r1 manage 15.4 K 2014-05-10 - 10:48 RezaGoldouzian exclusion plot tgammau
png tGulimit.png r1 manage 27.1 K 2014-05-11 - 11:44 RezaGoldouzian exclusion plot tgammau
pdf tcgammaBDT.pdf r1 manage 17.9 K 2014-05-10 - 09:07 RezaGoldouzian BDT output fot tcgamma signal channel
png tcgammaBDT.png r1 manage 31.3 K 2014-05-11 - 11:37 RezaGoldouzian exclusion plot tgammac
pdf tugammaBDT.pdf r1 manage 17.9 K 2014-05-10 - 09:02 RezaGoldouzian BDT output fot tugamma signal chanel
png tugammaBDT.png r1 manage 31.2 K 2014-05-11 - 11:37 RezaGoldouzian BDT output fot tugamma signal chanel
Topic revision: r12 - 2014-05-14 - AndreasMeyer

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