# APEC Seminar (Astronomy - Particle Physics - Experimental Physics - Cosmology)

Speaker: Chih-Ting Lu (NCTS Taiwan ) An exploratory study of Higgs-boson pair production at hadron colliders Thu, Jan 17, 2019, 15:30 - 16:30 Seminar Room A 2212.pdf Higgs-boson pair production is well known being capable to probe the trilinear self-coupling of the Higgsboson, which is one of the important ingredients of the Higgs sector itself. Pair production then depends on the top-quark Yukawa coupling $g^{S,P}_t$, Higgs trilinear coupling $\lambda_{3H}$, and a possible dim-5 contact-type ttHH coupling $g^{S,P}_{tt}$, which may appear in some higher representations of the Higgs sector. We take into account the possibility that the top-Yukawa and the ttHH couplings involved can be CPviolating. We calculate the cross sections and the interference terms as coefficients of the square or the 4th power of each coupling ($g^{S,P}_t, \lambda_{3H}, g^{S,P}_{tt}$) at various stages of cuts, such that the desired cross section under various cuts can be obtained by simply inputing the couplings. We employ the $HH\rightarrow\gamma\gamma b\overline{b}$ decay mode of the Higgs-boson pair to investigate the possibility of disentangle the triangle diagram from the box digram so as to have a clean probe of the trilinearcoupling at the LHC. On the other hand, we perform the most up-to-date comprehensive signal-background analysis for Higgs-pair production in $HH\rightarrow\gamma\gamma b\overline{b}$ channel at the HL-LHCand HL-100 TeV hadron collider, with the goal of probing the self-coupling $\lambda_{3H}$ of the Higgs boson. We simulate all the Standard Model signal and background processes with the simulation tools almost as sophisticated as what experimentalists are using. With all the simulated background events and results, our study can be useful to probe the Higgspotential of various models with extended Higgs sector, such as 2HDM, MSSM, etc.