Measurement of the top quark mass with lepton+jets final states using $$\mathrm {p}$$$$\mathrm {p}$$ collisions at $$\sqrt{s}=13\,\text {TeV} $$
Abstract
Abstract The mass of the top quark is measured using a sample of $${{\text {t}}\overline{{\text {t}}}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mtext>t</mml:mtext> <mml:mover> <mml:mtext>t</mml:mtext> <mml:mo>¯</mml:mo> </mml:mover> </mml:mrow> </mml:math> events collected by the CMS detector using proton-proton collisions at $$\sqrt{s}=13$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msqrt> <mml:mi>s</mml:mi> </mml:msqrt> <mml:mo>=</mml:mo> <mml:mn>13</mml:mn> </mml:mrow> </mml:math> $$\,\text {TeV}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mspace/> <mml:mtext>TeV</mml:mtext> </mml:mrow> </mml:math> at the CERN LHC. Events are selected with one isolated muon or electron and at least four jets from data corresponding to an integrated luminosity of 35.9 $$\,\text {fb}^{-1}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mspace/> <mml:msup> <mml:mtext>fb</mml:mtext> <mml:mrow> <mml:mo>-</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> </mml:mrow> </mml:math> . For each event the mass is reconstructed from a kinematic fit of the decay products to a $${{\text {t}}\overline{{\text {t}}}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mtext>t</mml:mtext> <mml:mover> <mml:mtext>t</mml:mtext> <mml:mo>¯</mml:mo> </mml:mover> </mml:mrow> </mml:math> hypothesis. Using the ideogram method, the top quark mass is determined simultaneously with an overall jet energy scale factor (JSF), constrained by the mass of the W boson in $${\text {q}} \overline{{\text {q}}} ^\prime $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mtext>q</mml:mtext> <mml:msup> <mml:mover> <mml:mtext>q</mml:mtext> <mml:mo>¯</mml:mo> </mml:mover> <mml:mo>′</mml:mo> </mml:msup> </mml:mrow> </mml:math> decays. The measurement is calibrated on samples simulated at next-to-leading order matched to a leading-order parton shower. The top quark mass is found to be $$172.25 \pm 0.08\,\text {(stat+JSF)} \pm 0.62\,\text {(syst)} \,\text {GeV} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>172.25</mml:mn> <mml:mo>±</mml:mo> <mml:mn>0.08</mml:mn> <mml:mspace/> <mml:mtext>(stat+JSF)</mml:mtext> <mml:mo>±</mml:mo> <mml:mn>0.62</mml:mn> <mml:mspace/> <mml:mtext>(syst)</mml:mtext> <mml:mspace/> <mml:mtext>GeV</mml:mtext> </mml:mrow> </mml:math> . The dependence of this result on the kinematic properties of the event is studied and compared to predictions of different models of $${{\text {t}}\overline{{\text {t}}}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mtext>t</mml:mtext> <mml:mover> <mml:mtext>t</mml:mtext> <mml:mo>¯</mml:mo> </mml:mover> </mml:mrow> </mml:math> production, and no indications of a bias in the measurements are observed.
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