As one of the major dark matter candidates, the ultralight Axion-Like Dark Matter (ALDM) exhibits a pronounced wave nature on astronomical scales and offers a promising solution to small-scale structure issues within local galaxies. While the linearly polarized pulsar light travels through the ALDM galactic halo, its position angle (PA) can be subject to an oscillation induced by the ALDM...
We discuss ways to extend the Standard Model quantum chromodynamics theory (QCD) theory and realize a first-order phase transition at high temperatures above 1 GeV without running into current constraints from heavy ion colliders and early cosmology. The phase transition is from a non-perturbative effect of the QCD. It can greatly impact the early universe, including gravitational wave signals...
The decay of the mediator particle into standard model (SM) particles
plays a significant role in exploring the dark sector scenario. We consider such a decay, taking the dark photon mediator as an example that mixes with the SM photon. We find that it requires a careful analysis of the decay rate in the presence of an SM vector boson
(e.g., Z boson, hadronic resonances, etc.) nearly...
An analytic calculation is given for binary star evaporation under the tidal perturbation from randomly distributed, spatially extended dark objects. In particular, the Milky Way's wide binary star population is susceptible to such disruption from dark matter solitons. We identify high-probability `halo-like' wide binaries in GAIA EDR3 with separations larger than 0.1 parsec. Survival of the...
The chiral phase transition in QCD can be supercooled in the thermal history of the universe to be instantaneously out-of equilibrium, if QCD is coupled to a dark QCD sector exhibiting the dark chiral phase transition of the first order. In that case the QCD sigma meson field (as the chiral order parameter, or the light quark condensate) starts to roll in a nonadiabatic way down to the true...
The electroweak (EW) phase transition in the early Universe might be supercooled due to the presence of the classical scale invariance involving Beyond the Standard Model (BSM) sectors and the supercooling could persist down till a later epoch around which the QCD chiral phase transition is supposed to take place. Since this supercooling period keeps masslessness for all the six SM quarks, it...
We propose a hybrid inflationary scenario based on eight-flavor hidden QCD with the hidden colored fermions being in part gauged under $U(1)_{B-L}$. This hidden QCD is almost scale-invariant, so-called walking, and predicts the light scalar meson (the walking dilaton) associated with the spontaneous scale breaking, which develops
the Coleman-Weinberg (CW) type potential as the consequence...
The Event Horizon Telescope (EHT) has revolutionized our ability to study black holes by providing unprecedented spatial resolution and unveiling horizon-scale details. With advancements leading to the next-generation EHT, there is potential to probe even deeper into the black hole's dark region, especially the inner shadow characterized by low-intensity foreground emissions from the jet,...
The Very Large Area gamma-ray Space Telescope (VLAST) is a mission concept proposed to detect gamma-ray photons through both the Compton scattering and electron-positron pair production mechanisms, enabling the detection of photons with energies ranging from MeV to TeV. VLAST is designed to have an acceptance of 10 m^2 sr which is four times larger than Fermi-LAT, an energy resolution of ~2%...
This talk plans to introduce a couple of recent new phenomenologies and cosmology related to the QCD phase transition epoch, coupled to Beyond the Standard Model, in the thermal history of the universe. Baryogenesis, strong CP problem, and gravitational wave predictions will be covered in scenarios of this class, which can also be embedded into the scalegenesis to address the dynamical origin...
In this talk, I will discuss the excellent potential of neutrino neutral current interaction with 13C in neutrino experiments. The interaction induces the excited state 13C* subsequently emitting a 3.685 MeV photon from the de-excitation into the ground state. The probe of this distinctive signal can shed light in identifying the origin of the 5 MeV bump observed in reactor anti-neutrino...
Dark SHINE is a fixed-target experiment initiative to search for light Dark Matter and mediators at SHINE (Shanghai high repetition rate XFEL and extreme light facility, being the 1st hard X-ray FEL in China) under construction targeting completion in 2026. Dark SHINE aims to search for the new mediator, Dark Photon, bridging the Dark sector and the ordinary matter. In this work and...
Ref: https://arxiv.org/abs/2306.00641
Results from a wide range of searches targeting different experimental signatures with and without missing transverse momentum ($𝐸^{𝑚𝑖𝑠𝑠}_{𝑇}$) are used to constrain a Two-Higgs-Doublet Model (2HDM) with an additional pseudo-scalar mediating the interaction between ordinary and dark matter (2HDM+a). The analyses use up to 139 fb$^{−1}$ of proton-proton...
The strong CP problem is one of the most important problem in the standard model. One plausible approach is spontaneous CP violation, where CP is an exact symmetry but is spontaneously broken to introduce the observed Cabibbo-Kobayashi-Maskawa (CKM) phase without producing large strong CP phase. In this talk, we present a composite model of spontaneous CP violation in supersymmetric QCD. The...
Anomalous gauge couplings provide unique insights into dimension-8 physics, which can be studied in great detail through multi-boson processes at high-energy colliders. In this talk, I will review our recent studies on anomalous gauge couplings in multi-boson physics. This includes tri-boson and vector boson scattering productions, probes on anomalous couplings, and the applications of machine...
arXiv: 2407.06523 [hep-ph]:
We study the ultraviolet completion of semileptonic four-fermion operator $O_{ledq}^{\alpha \beta 11}$ that incorporates Majorana dark matter (DM) in both lepton-flavor-conserving (LFC) and lepton-flavor-violating (LFV) scenarios at the one-loop level via box diagram, which effectively alleviates the lower bounds on the new physics scale. The interplay between the...
We present a consistent derivation of the complete Wess-Zumino-Witten
interactions of axions, including the counter-term necessary to guarantee the
gauge invariance of the Standard Model. By treating the derivative of the axion
field as a background gauge field and incorporating auxiliary chiral rotation
phases, we ensure consistency in the axion-interaction Lagrangian. This
approach...
Certain dimension-8 operator coefficients are subject to positivity bounds, derived from the fundamental principles of Quantum Field Theory, including unitarity, locality, analyticity and Lorentz invariance. In the first part of the talk, I will discuss how these positivity bounds can be probed by LHC or future lepton colliders. In the second part of the talk, I will discuss some of the...
As the theoretical and experimental studies have entered the precision era, I will discuss some of the most well-motivated dark matter models in direct and indirect searches, with special focus on light dark matter.
We will discuss the remaining parameter space for WIMP-like dark matter with thermal relic density, focusing on two scenarios: the small interaction rate region and the small mass region. In the small interaction rate region, we reanalyze the prospects of detecting dark matter annihilation signals in the Galactic Center, particularly near the supermassive black hole (Sgr A*), by examining...
We will discuss the remaining parameter space for WIMP-like dark matter with thermal relic density, focusing on two scenarios: the small interaction rate region and the small mass region. In the small interaction rate region, we reanalyze the prospects of detecting dark matter annihilation signals in the Galactic Center, particularly near the supermassive black hole (Sgr A*), by examining...
