Search for Higgs Boson Decay to a Charm Quark-Antiquark Pair in Proton-Proton Collisions at <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msqrt><mml:mi>s</mml:mi></mml:msqrt><mml:mo>=</mml:mo><mml:mn>13</mml:mn><mml:mtext> </mml:mtext><mml:mtext> </mml:mtext><mml:mi>TeV</mml:mi></mml:math>
A. Tumasyan, W. Adam, Janik Walter Andrejkovic, T. Bergauer, S. Chatterjee, K. Damanakis, M. Dragicevic, A. Escalante Del Valle, Priya Sajid Hussain, M. Jeitler, Natascha Krammer, L. Lechner, D. Liko, I. Mikulec, P. Paulitsch, F. M. Pitters, J. Schieck, R. Schöfbeck, D. Schwarz, S. Templ, W. Waltenberger, C.-E. Wulz, M. R. Darwish, X. Janssen, T. Kello, Haifa Rejeb Sfar, P. Van Mechelen, E. S. Bols, J. D’Hondt, A. De Moor, M. Delcourt, H. El Faham, S. Lowette, S. Moortgat, A. Morton, D. Müller, A. R. Sahasransu, S. Tavernier, W. Van Doninck, D. Vannerom, B. Clerbaux, G. De Lentdecker, L. Favart, J. Jaramillo, K. Lee, M. Mahdavikhorrami, I. Makarenko, A. Malara, S. Paredes, L. Pétré, N. Postiau, E. Starling, Laurent Thomas, M. Vanden Bemden, C. Vander Velde, P. Vanlaer, D. Dobur, J. Knolle, Luka Lambrecht, Gianny Mestdach, M. Niedziela, C. Rendón, C. Roskas, Amrutha Samalan, K. Skovpen, M. Tytgat, N. Van Den Bossche, B. Vermassen, Liam Wezenbeek, A. Benecke, A. Bethani, G. Bruno, F. Bury, C. Caputo, P. David, C. Delaere, I. S. Donertas, A. Giammanco, K. Jaffel, Sa. Jain, V. Lemaı̂tre, K. Mondal, J. Prisciandaro, A. Taliercio, T. T. Tran, P. Vischia, S. Wertz, G. A. Alves, E. Coelho, C. Hensel, A. Moraes, P. Rebello Teles, W. L. Aldá Júnior, M. Alves Gallo Pereira, M. Barroso Ferreira Filho, H. Brandao Malbouisson, W. Carvalho, J. Chinellato, E. M. Da Costa, G. G. Da Silveira
Abstract
A search for the standard model Higgs boson decaying to a charm quark-antiquark pair, H→cc[over ¯], produced in association with a leptonically decaying V (W or Z) boson is presented. The search is performed with proton-proton collisions at sqrt[s]=13 TeV collected by the CMS experiment, corresponding to an integrated luminosity of 138 fb^{-1}. Novel charm jet identification and analysis methods using machine learning techniques are employed. The analysis is validated by searching for Z→cc[over ¯] in VZ events, leading to its first observation at a hadron collider with a significance of 5.7 standard deviations. The observed (expected) upper limit on σ(VH)B(H→cc[over ¯]) is 0.94 (0.50_{-0.15}^{+0.22})pb at 95% confidence level (C.L.), corresponding to 14 (7.6_{-2.3}^{+3.4}) times the standard model prediction. For the Higgs-charm Yukawa coupling modifier, κ_{c}, the observed (expected) 95% C.L. interval is 1.1<|κ_{c}|<5.5 (|κ_{c}|<3.4), the most stringent constraint to date.