第十二届中国 LHC 物理会议（CLHCP2026）

In this talk, I will discuss several different scenarios about testing CP-violation at high energy colliders, based on some recent progresses and forthcoming projects from my group. We studied CP-violation effects both from pure bosonic sector and the Yukawa sector. For pure bosonic sector, we considered a heavy Higgs boson produced through VBF process and decaying through Zh(125) channel,...

PQ solution to the strong CP problem probably encounters the axion domain wall problem. In this article, we propose a simple and testable solution, assuming that the U(1)PQU(1)PQ possesses mixed anomaly to a hidden SU(Nc)SU(Nc) color. Then, the axion field receives a new cosine potential from the hidden instantons, which breaks the ZNDWZNDW subgroup explicitly. The new potential lifts the...

Soft unclustered energy patterns (SUEPs) refer to high-multiplicity, isotropic distributions of low-momentum particles that could arise in strongly-coupled hidden sector theories. A search for SUEPs whose decay products contain muons in the final state is presented using 140 fb−1 of proton–proton collision data at √ = 13 TeV collected by the ATLAS detector at the Large Hadron Collider during...

Spin-dependent dihadron fragmentation provides a unique way to access the polarization and spin correlations of light quarks and gluons at lepton colliders. In this talk, I will discuss how dihadron fragmentation can serve as a spin analyzer and be used to study a range of phenomena, including Bell inequality violation, anomalous electromagnetic dipole interactions, light-quark Yukawa...

LHC measurements now reconstruct all fifteen parameters of the $t\bar{t}$ two-qubit spin density matrix, which amounts to a full quantum tomography of the pair. We show that this data constrains CP violation in the top-Yukawa coupling. The coupling enters the density matrix at one loop and produces spin correlations that are odd under CP and do not affect the cross section. Using the first...