Measurement of the Jet Mass Distribution and Top Quark Mass in Hadronic Decays of Boosted Top Quarks in $pp$ Collisions at $\sqrt{s} =$ TeV

• Published in: Physical review letters Vol. 124; no. 20
• Main Authors: Sirunyan, Albert M, Tumasyan, Armen, Adam, Wolfgang, Ambrogi, Federico, Bergauer, Thomas, Brandstetter, Johannes, Dragicevic, Marko, Erö, Janos, Escalante del Valle, Alberto, Flechl, Martin, Fruehwirth, Rudolf, Jeitler, Manfred, Krammer, Natascha, Krätschmer, Ilse, Liko, Dietrich, Madlener, Thomas, Mikulec, Ivan, Rad, Navid, Schieck, Jochen, Schöfbeck, Robert, Spanring, Markus, Spitzbart, Daniel, Waltenberger, Wolfgang, Wulz, Claudia-Elisabeth, Zarucki, Mateusz, Drugakov, Vladimir, Mossolov, Vladimir, Suarez Gonzalez, Juan, Darwish, Mohamed Rashad, de Wolf, Eddi A, Di Croce, Davide, Janssen, Xavier, Lelek, Aleksandra, Pieters, Maxim, Rejeb Sfar, Haifa, van Haevermaet, Hans, van Mechelen, Pierre, van Putte, Senne, van Remortel, Nick, Blekman, Freya, Bols, Emil Sørensen, Chhibra, Simranjit Singh, d'Hondt, Jorgen, de Clercq, Jarne, Lontkovskyi, Denys, Lowette, Steven, Marchesini, Ivan, Moortgat, Seth, Python, Quentin, Skovpen, Kirill, Tavernier, Stefaan, van Doninck, Walter, van Mulders, Petra, Beghin, Diego, Bilin, Bugra, Brun, Hugues, Clerbaux, Barbara, de Lentdecker, Gilles, Delannoy, Hugo, Dorney, Brian, Favart, Laurent, Grebenyuk, Anastasia, Kalsi, Amandeep Kaur, Popov, Andrey, Postiau, Nicolas, Starling, Elizabeth, Thomas, Laurent, Vander Velde, Catherine, Vanlaer, Pascal, Vannerom, David, Cornelis, Tom, Dobur, Didar, Khvastunov, Illia, Niedziela, Marek, Roskas, Christos, Trocino, Daniele, Tytgat, Michael, Verbeke, Willem, Vermassen, Basile, Vit, Martina, Bondu, Olivier, Bruno, Giacomo, Caputo, Claudio, David, Pieter, Delaere, Christophe, Delcourt, Martin, Giammanco, Andrea, Lemaitre, Vincent, Prisciandaro, Jessica, Saggio, Alessia, Vidal Marono, Miguel, Vischia, Pietro, Zobec, Joze, Alves, Fábio Lúcio, Alves, Gilvan, Correia Silva, Gilson, Hensel, Carsten, Moraes, Arthur, Rebello Teles, Patricia, Belchior Batista das Chagas, Ewerton
• Format: Journal Article
• Language: English
• Published: American Physical Society 2020
• Subjects: High Energy Physics - Experiment; Physics; experimental results; jet: mass spectrum; mass dependence; CMS; CERN LHC Coll; Elementary Particles and Fields; top: mass: measured; top: pair production; channel cross section: measured; track data analysis: jet; Q007TP; data analysis method; top: decay; muon; jet: transverse momentum; electron; p p: colliding beams; p p: scattering; top: boosted particle; jet: mass; 13000 GeV-cms
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/PhysRevLett.124.202001

A measurement is reported of the jet mass distribution in hadronic decays of boosted top quarks produced in pp collisions at s=13  TeV. The data were collected with the CMS detector at the LHC and correspond to an integrated luminosity of 35.9  fb-1. The measurement is performed in the lepton+jets channel of tt¯ events, where the lepton is an electron or muon. The products of the hadronic top quark decay t→bW→bqq¯′ are reconstructed as a single jet with transverse momentum larger than 400 GeV. The tt¯ cross section as a function of the jet mass is unfolded at the particle level and used to extract a value of the top quark mass of 172.6±2.5  GeV. A novel jet reconstruction technique is used for the first time at the LHC, which improves the precision by a factor of 3 relative to an earlier measurement. This highlights the potential of measurements using boosted top quarks, where the new technique will enable future precision measurements.