Search for single vector-like B quark production and decay via B → bH($$ b\overline{b} $$) in pp collisions at $$ \sqrt{s} $$ = 13 TeV with the ATLAS detector
G. Aad, B. Abbott, D. C. Abbott, A. Abed Abud, K. Abeling, D. K. Abhayasinghe, S. H. Abidi, H. Abramowicz, H. Abreu, Y. Abulaiti, A. C. Abusleme Hoffman, B. S. Acharya, B. Achkar, L. Adámek, C. Adam Bourdarios, L. Adamczyk, L. Adámek, J. Adelman, A. Adıgüzel, S. Adorni, T. Adye, A. A. Affolder, Y. Afik, C. Agapopoulou, M. N. Agaras, J. Agarwala, A. Aggarwal, C. Agheorghiesei, J. A. Aguilar–Saavedra, A. Ahmad, F. Ahmadov, W. S. Ahmed, X. Ai, G. Aielli, Shunichi Akatsuka, M. Akbiyik, T. P. A. Åkesson, A. V. Akimov, K. Al Khoury, G. L. Alberghi, J. Albert, M. J. Alconada Verzini, S. Alderweireldt, M. Aleksa, I. N. Aleksandrov, C. Alexa, T. Alexopoulos, A. Alfonsi, Fabrizio Alfonsi, M. Alhroob, B. Ali, S. Ali, M. Aliev, G. Alimonti, C. Allaire, Benedict Allbrooke, P. P. Allport, A. Aloisio, F. Alonso, C. Alpigiani, Elio Alunno Camelia, M. Alvarez Estevez, M. G. Alviggi, Y. Amaral Coutinho, A. Ambler, L. Ambroz, Christoph Amelung, D. Amidei, S. P. Amor Dos Santos, S. Amoroso, Cherifa Sabrina Amrouche, C. Anastopoulos, N. Andari, T. Andeen, J. K. Anders, S. Y. Andrean, A. Andreazza, Victor Andrei, S. Angelidakis, A. Angerami, A. V. Anisenkov, A. Annovi, C. Antel, M. T. Anthony, E. Antipov, M. Antonelli, D. J. A. Antrim, F. Anulli, M. Aoki, J. A. Aparisi Pozo, M. A. Aparo, L. Aperio Bella, Nordin Aranzabal Barrio, V. Araujo Ferraz, C. Arcangeletti, A. T. H. Arce, Eloisa Arena, J-F. Arguin, S. Argyropoulos, J.-H. Arling
Abstract
A bstract A search is presented for single production of a vector-like B quark decaying into a Standard Model b -quark and a Standard Model Higgs boson, which decays into a $$ b\overline{b} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>b</mml:mi> <mml:mover> <mml:mi>b</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> pair. The search is carried out in 139 fb − 1 of $$ \sqrt{s} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msqrt> <mml:mi>s</mml:mi> </mml:msqrt> </mml:math> = 13 TeV proton-proton collision data collected by the ATLAS detector at the LHC between 2015 and 2018. No significant deviation from the Standard Model background prediction is observed, and mass-dependent exclusion limits at the 95% confidence level are set on the resonance production cross-section in several theoretical scenarios determined by the couplings c W , c Z and c H between the B quark and the Standard Model W , Z and Higgs bosons, respectively. For a vector-like B occurring as an isospin singlet, the search excludes values of c W greater than 0.45 for a B resonance mass ( m B ) between 1.0 and 1.2 TeV. For 1 . 2 TeV < m B < 2 . 0 TeV, c W values larger than 0.50–0.65 are excluded. If the B occurs as part of a ( B, Y ) doublet, the smallest excluded c Z coupling values range between 0.3 and 0.5 across the investigated resonance mass range 1 . 0 TeV < m B < 2 . 0 TeV.