The first evidence of events consistent with the production of a single top quark in association with a photon is reported. The analysis is based on proton-proton collisions at s=13 TeV and recorded by the CMS experiment in 2016, corresponding to an integrated luminosity of 35.9 fb-1. Events are selected by requiring the presence of a muon (μ), a photon (γ), an imbalance in transverse momentum from an undetected neutrino (ν), and at least two jets (j) of which exactly one is identified as associated with the hadronization of a b quark. A multivariate discriminant based on topological and kinematic event properties is employed to separate signal from background processes. An excess above the background-only hypothesis is observed, with a significance of 4.4 standard deviations. A fiducial cross section is measured for isolated photons with transverse momentum greater than 25 GeV in the central region of the detector. The measured product of the cross section and branching fraction is σ(pp→tγj)B(t→μνb)=115±17(stat)±30(syst) fb, which is consistent with the standard model prediction.
Jian Wang, Matthias Finger, Qian Wang, Yiming Li, Matthias Wolf, Varun Sharma, Yi Zhang, Konstantin Androsov, Jan Steggemann, Xin Chen, Rakesh Chawla, Matteo Galli, Anna Mascellani, João Miguel das Neves Duarte, Tagir Aushev, Tian Cheng, Yixing Chen, Werner Lustermann, Andromachi Tsirou, Alexis Kalogeropoulos, Andrea Rizzi, Ioannis Papadopoulos, Paolo Ronchese, Hua Zhang, Siyuan Wang, Tao Huang, David Vannerom, Michele Bianco, Sebastiana Gianì, Sun Hee Kim, Kun Shi, Abhisek Datta, Federica Legger, Gabriele Grosso, Ji Hyun Kim, Donghyun Kim, Zheng Wang, Sanjeev Kumar, Wei Li, Yong Yang, Ajay Kumar, Ashish Sharma, Georgios Anagnostou, Joao Varela, Csaba Hajdu, Muhammad Ahmad, Ioannis Evangelou, Milos Dordevic, Meng Xiao, Sourav Sen, Xiao Wang, Kai Yi, Jing Li, Rajat Gupta, Hui Wang, Seungkyu Ha, Pratyush Das, Anton Petrov, Xin Sun, Valérie Scheurer, Muhammad Ansar Iqbal
Jian Wang, Matthias Finger, Qian Wang, Yiming Li, Matthias Wolf, Varun Sharma, Yi Zhang, Konstantin Androsov, Jan Steggemann, Leonardo Cristella, Xin Chen, Davide Di Croce, Arvind Shah, Rakesh Chawla, Chao Wang, João Miguel das Neves Duarte, Tagir Aushev, Tian Cheng, Yixing Chen, Werner Lustermann, Andromachi Tsirou, Alexis Kalogeropoulos, Andrea Rizzi, Ioannis Papadopoulos, Paolo Ronchese, Hua Zhang, Siyuan Wang, Jessica Prisciandaro, Peter Hansen, Tao Huang, David Vannerom, Michele Bianco, Sebastiana Gianì, Kun Shi, Wei Shi, Abhisek Datta, Wei Sun, Jian Zhao, Thomas Berger, Federica Legger, Doohyun Kim, Bertrand François, Bandeep Singh, Ji Hyun Kim, Donghyun Kim, Dipanwita Dutta, Zheng Wang, Sanjeev Kumar, Wei Li, Yong Yang, Yi Wang, Ajay Kumar, Ashish Sharma, Georgios Anagnostou, Joao Varela, Csaba Hajdu, Muhammad Ahmad, Ekaterina Kuznetsova, Ioannis Evangelou, Matthias Weber, Muhammad Shoaib, Milos Dordevic, Vineet Kumar, Vladimir Petrov, Francesco Fiori, Quentin Python, Meng Xiao, Sourav Sen, Viktor Khristenko, Fan Xia, Xiao Wang, Kai Yi, Jing Li, Rajat Gupta, Muhammad Waqas, Hui Wang, Seungkyu Ha, Maren Tabea Meinhard, Giorgia Rauco, Ali Harb, Benjamin William Allen, Pratyush Das, Miao Hu, Anton Petrov, Valérie Scheurer, Muhammad Ansar Iqbal, Lukas Layer
Jian Wang, Lesya Shchutska, Olivier Schneider, Yiming Li, Yi Zhang, Aurelio Bay, Guido Haefeli, Christoph Frei, Frédéric Blanc, Tatsuya Nakada, Michel De Cian, François Fleuret, Elena Graverini, Renato Quagliani, Federico Betti, Aravindhan Venkateswaran, Luis Miguel Garcia Martin, Vitalii Lisovskyi, Sebastian Schulte, Veronica Sølund Kirsebom, Elisabeth Maria Niel, Mingkui Wang, Zhirui Xu, Chao Wang, Lei Zhang, Ho Ling Li, Mark Tobin, Minh Tâm Tran, Niko Neufeld, Matthew Needham, Marc-Olivier Bettler, Maurizio Martinelli, Vladislav Balagura, Donal Patrick Hill, Liang Sun, Pietro Marino, Mirco Dorigo, Xiaoxue Han, Liupan An, Federico Leo Redi, Plamen Hristov Hopchev, Maxime Schubiger, Hang Yin, Guido Andreassi, Violaine Bellée, Preema Rennee Pais, Pavol Stefko, Tara Nanut, Maria Elena Stramaglia, Yao Zhou, Tommaso Colombo, Vladimir Macko, Guillaume Max Pietrzyk, Evgenii Shmanin, Simone Meloni, Xiaoqing Zhou, Surapat Ek-In, Carina Trippl, Sara Celani, Marco Guarise, Serhii Cholak, Dipanwita Dutta, Zheng Wang, Yong Yang, Yi Wang, Hao Liu, Hans Dijkstra, Gerhard Raven, Peter Clarke, Frédéric Teubert, Giovanni Carboni, Victor Coco, Shuai Liu, Adam Davis, Paolo Durante, Yu Zheng, Anton Petrov, Maxim Borisyak, Feng Jiang, Zhipeng Tang, Xuan Li, Alexey Boldyrev, Almagul Kondybayeva, Hossein Afsharnia