Search for Flavour Changing Neutral Current Couplings of Higgs-up Sector Quarks at Future Circular Collider (FCC-eh)

In the search for new physics beyond the Standard
Model, Flavour Changing Neutral Current (FCNC) is a good research
field in terms of the observability at future colliders. Increased
Higgs production with higher energy and luminosity in colliders
is essential for verification or falsification of our knowledge of
physics and predictions, and the search for new physics. Prospective
electron-proton collider constituent of the Future Circular Collider
project is FCC-eh. It offers great sensitivity due to its high luminosity
and low interference. In this work, thq FCNC interaction vertex
with off-shell top quark decay at electron-proton colliders is studied.
By using MadGraph5_aMC@NLO multi-purpose event generator,
observability of tuh and tch couplings are obtained with equal
coupling scenario. Upper limit on branching ratio of tree level top
quark FCNC decay is determined as 0.012% at FCC-eh with 1 ab ^−1
luminosity.

Authors:

• I. Turk Cakir
• B. Hacisahinoglu
• S. Kartal
• A. Yilmaz
• A. Yilmaz
• Z. Uysal
• O. Cakir

Keywords:

• FCC
• FCNC
• Higgs Boson
• Top Quark.

References:

[1] S. L. Glashow, J. Iliopoulos, and L.Maiani, “Weak Interactions with
Lepton-Hadron Symmetry,” Phys. Rev. D, vol. 2, no 7, 1285, (1970).
[2] J. A. Aguilar-Saavedra, “Top flavour-changing neutral interactions:
theoretical expectations and experimental detection,” Acta Phys. Polon.
B 35, 2695-2710,2004, arXiv:0409342v4 [hep-ph].
[3] O. Bruning, J. Jowett, M. Klein, D. Pellegrini, D. Schulte, and
F. Zimmermann, “Future Circular Collider Study FCC-he Baseline
Parameters,” Tech. Rep. CERN-ACC-2017-0019, CERN, Geneva, Apr
2017.
[4] J. L. Abelleira Fernandez et al. (LHeC Study Group), “A Large Hadron
Electron Collider At CERN,” J. Phys. G: Nucl. Part. Phys., vol. 39,
075001, June 2012.
[5] The ATLAS collaboration, Aad, G., Abbott, B. et al. J. High Energ.
Phys. (2015) 2015: 1. https://doi.org/10.1007/JHEP12(2015)061.
[6] The CMS collaboration, Khachatryan, V., Sirunyan,
A.M. et al. J. High Energ. Phys. (2017) 2017: 79.
https://doi.org/10.1007/JHEP02(2017)079.
[7] J. Alwall et al, “The automated computation of tree-level and
next-to-leading order differential cross sections, and their matching to
parton shower simulations,” 2014, arXiv:1405.0301 [hep-ph].
[8] C. Degrande, C. Duhr, B. Fuks, D. Grellscheid, O. Mattelaer and
T. Reiter, Comput. Phys. Commun., vol. 183, 1201-1214, June 2012,
arXiv:1108.2040 [hep-ph].
[9] Mathieu Buchkremer, Giacomo Cacciapaglia, Aldo Deandrea, Luca
Panizzi, “Model-independent framework for searches of top partners,”
Nuclear Physics B, Vol. 876, Issue 2, pp. 376-417, Nov. 2013.
[10] Ling-Lie Chau and Wai-Yee Keung, “Comments on the Parametrization
of the Kobayashi-Maskawa Matrix,” Phys. Rev. Lett. vol. 53, no. 4,
1802-1805, Nov. 1984.
[11] C. Patrignani et al. (Particle Data Group), Chin. Phys. C, vol. 40, 100001
(2016).
[12] Chong Sheng Li, Robert J. Oakes, and Tzu Chiang Yuan, “QCD
corrections to t → W+ + b,” Phys. Rev. D, vol. 43, pp. 3759-3762,
June 1991.
[13] Wei-Shu Hou, “Tree level t → ch0 or h0 → tc decays,” Physics Letters
B, vol. 296, Issues 1–2, pp. 179-184, Dec. 1992.
[14] Wei Liu, Hao Sun, XiaoJuan Wang, Xuan Luo, “Probing the anomalous
FCNC top-Higgs Yukawa couplings at the Large Hadron Electron
Collider,” Phys. Rev. D, vol 92, , pp. 074015 1-10, Oct. 2015.
[15] XiaoJuan Wang, Hao Sun, and Xuan Luo, “Searches for the Anomalous
FCNC Top-Higgs Couplings with Polarized Electron Beam at the
LHeC,” Advances in High Energy Physics, vol. 2017, Article ID
4693213, pp.1-9, Mar. 2017.