Exploring top-quark signatures of heavy flavor-violating scalars at the LHC

In this work, we study flavor-violating scalars (flavons) in a range of large masses that have not been explored previously. We model the interactions with an effective field theory formulation where the flavon is heavier than the top quark. In addition, we assume that the flavon only couples to fermions of the standard model in a flavor-changing way, making it easier to escape experimental constraints. As the flavon couples strongly to top quarks, same-sign and opposite-sign top-quark pair signals can be explored in the search for those particles. We investigate the possibility of probing flavons through their interactions with a top quark plus up and charm quarks for effective couplings of order <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:msup><a:mrow><a:mn>10</a:mn></a:mrow><a:mrow><a:mo>−</a:mo><a:mn>2</a:mn></a:mrow></a:msup><a:mtext> </a:mtext><a:mtext> </a:mtext><a:mi>TeV</a:mi></a:mrow></a:math> and masses in the <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:mrow><c:mo>∼</c:mo><c:mn>200</c:mn><c:mi>–</c:mi><c:mn>1400</c:mn><c:mtext> </c:mtext><c:mtext> </c:mtext><c:mi>GeV</c:mi></c:mrow></c:math> range in the 14 TeV LHC in scenarios with up to <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"><e:mrow><e:mn>3000</e:mn><e:mo>/</e:mo><e:mi>fb</e:mi></e:mrow></e:math>.