Higgs potential and BSM opportunity 希格斯物理研讨会

We propose a novel primordial black hole (PBH) formation mechanism based on a first-order phase transition (FOPT). If a fermion species gains a huge mass in the true vacuum, the corresponding particles get trapped in the false vacuum as they do not have sufficient energy to penetrate the bubble wall. After the FOPT, the fermions are compressed into the false vacuum remnants to form...

We derive an effective equation-of-motion for an expanding bubble wall in the thermal plasma with a general form of the thermal friction. The efficiency factor for gravitational waves productions from colliding bubble walls is obtained with a special interest for the strong first-order phase transition. Primary authors Prof. Rong-Gen Cai (ITP-CAS)， Shao-Jiang Wang

The energy budget of electroweak first-order phase transition is essential for the gravitational wave spectra. Most of the previous studies are based on the bag model with same sound velocity in the symmetric and broken phase. We study the energy budget and the corresponding gravitational wave spectra beyond the bag model, where the sound velocities could be different in the symmetric and...

We numerically investigate the B+L violation process by performing three-dimensional lattice simulations of a unified scenario of first-order phase transitions and the sphaleron generation. The simulation results indicate that the Chern-Simons number changes along with the helical magnetic field production when the sphaleron decay occurs. Based on these numerical results, we then propose a...

We study the complementarity of the proposed multi-TeV muon colliders and the near-future gravitational wave (GW) detectors to the first order electroweak phase transition (FOEWPT), taking the real scalar extended Standard Model as the representative model. A detailed collider simulation shows the FOEWPT parameter space can be greatly probed via the the vector boson fusion production of the...

Searches are performed for non-resonant and resonant di-Higgs boson production in the ̄ final state. The data set used corresponds to an integrated luminosity of 139 fb−1 of proton–proton collisions at a center-of-mass energy of 13 TeV recorded by the ATLAS detector at the CERN Large Hadron Collider. No excess with respect to background expectations is found and upper limits on the...

A search for non-resonant and resonant Higgs boson pair production in bbττ final states is conducted using p-p collision data with an integrated luminosity of 139 fb−1 collected at s=√13 TeV by the ATLAS detector at the LHC. Events with at least one τ-lepton decaying hadronically are considered. Multivariate analysis techniques are used to extract the signals. The talk will show an overview of...

We study the measurement of Higgs boson self-couplings through 2 → 3 vector boson scattering (VBS) processes in the framework of Standard Model effective field theory (SMEFT) at both proton and lepton colliders. The SMEFT contribution to the amplitude of the 2 → 3 VBS processes, taking WLWL → WLWLh and WLWL → hhh as examples, exhibits enhancement with the energy A(BSM)/A(SM) ~which indicates...

A study showed that the multilepton anomalies in the LHC data could be explained by adding two real scalar bosons to the SM. This study provides a more comprehensive set of LHC results of the multilepton production. We find that combining such results leads to substantial inconsistencies between the data and SM Monte Carlo predictions. These discrepancies appear in corners of the phase-space...

Advances in boosted jet tagging techniques, particularly with novel machine learning approaches, have led to significant performance improvements in the reconstruction and identification of the hadronic decays of the Higgs boson and provided additional handles to probe the Higgs boson properties at the LHC. In this talk, I will present recent progress in machine learning-based methods for...

I will discuss the general difficulty in New Physics search, and how to put an upper limit on New Physics scale (which can be detected or excluded in the near future) via strong 1st order electroweak phase transition.