Golden Probe of the Top Yukuwa
We perform a preliminary study of the ability of the Higgs decay to four leptons to shed light on the top quark Yukawa couplings. In particular we examine whether the h → 4ℓ 'golden channel' is sensitive to the CP properties of the top quark couplings to the Higgs boson. We show that kinematic distributions are sensitive to interference of the next-to-leading order electroweak corrections with the tree level ZZ contribution. This translates into a sensitivity to the top quark Yukawa couplings such that meaningful constraints on their CP properties can begin to be obtained once ~ 300 fb^(-1) of data has been collected at ~ 14 TeV, with significant improvements at higher luminosity or with a higher energy hadron collider. This makes the h → 4ℓ channel a useful probe of the top quark Yukawa couplings that is qualitatively different from already established searches in h → Vy two body decays, tth, and gg→h. We also briefly discuss other potential possibilities for probing the top Yukawa CP properties in h→2ℓγ and ℓ+ℓ−→hZ,hγ.
©2015 American Physical Society. This article is available under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. (Received 1 June 2015; published 14 September 2015) We thank Maria Spiropulu for providing us with the resources necessary to complete this study as well as Simon Badger, Fabrizio Caola, Adam Falkowski, Gian Giudice, Roni Harnik, Joe Lykken, Tom Melia, Matthew McCullough, Markus Schulze, Pedro Schwaller, and Tim Tait for comments and helpful discussions. R. V. M. is supported by the ERC Advanced Grant Higgs@LHC. Y. C. is supported by the Weston Havens Foundation and DOE Grant No. DE-FG02-92-ER-40701. D. S. and R. V. M. would also like to thank the participants of the workshop "After the Discovery: Hunting for a Non-Standard Higgs Sector" at Centro de Ciencias de Benasque Pedro Pascual for lively atmosphere and discussions where this work began.
Submitted - 1505.01168v2.pdf
Published - PhysRevD.92.053003.pdf