Search for electroweak production of a vector-like quark decaying to a top quark and a Higgs boson using boosted topologies in fully hadronic final states

• Main Authors: Sirunyan, A. M., Tumasyan, A. R., Adam, Wolfgang, Asilar, Ece, Bergauer, Thomas, Md. Ali, Mohd. Adli
• Format: Article
• Language: English; English
• Published: Springer Verlag 2017
• Subjects: Q Science (General); QC Physics
• Online Access: http://irep.iium.edu.my/63070/1/63070_Search%20for%20electroweak%20production_article.pdf; http://irep.iium.edu.my/63070/2/63070_Search%20for%20electroweak%20production_scopus.pdf; http://irep.iium.edu.my/63070/; https://link.springer.com/content/pdf/10.1007%2FJHEP11%282017%29029.pdf
• Institution: Universiti Islam Antarabangsa Malaysia

A search is performed for electroweak production of a vector-like top quark partner T of charge 2/3 in association with a standard model top or bottom quark, using 2.3 fb−1 of proton-proton collision data at √ s = 13 TeV collected by the CMS experiment at the CERN LHC. The search targets T quarks decaying to a top quark and a Higgs boson in fully hadronic final states. For a T quark with mass above 1 TeV the daughter top quark and Higgs boson are highly Lorentz-boosted and can each appear as a single hadronic jet. Jet substructure and b tagging techniques are used to identify the top quark and Higgs boson jets, and to suppress the standard model backgrounds. An excess of events is searched for in the T quark candidate mass distribution in the data, which is found to be consistent with the expected backgrounds. Upper limits at 95% confidence level are set on the product of the single T quark production cross sections and the branching fraction B(T → tH), and these vary between 0.31 and 0.93 pb for T quark masses in the range 1000–1800 GeV. This is the first search for single electroweak production of a vector-like T quark in fully hadronic final states.