Di-Higgs enhancement by neutral scalar as probe of new colored sector Koji Nakamura, Kenji Nishiwaki, Kin-ya Oda, Seong Chan Park and Yasuhiro Yamamoto Eur. Phys. J. C, 77 5 (2017) 273 Published online: 02 May 2017 DOI: 10.1140/epjc/s10052-017-4835-4