This talk reviews the historical path from the proposal of parity nonconservation to the establishment of the Standard Model. We trace the development from parity-violation experiments and the V–A theory through current algebra, flavor mixing, CP violation to the electroweak theory and beyond. This evolution illustrates how this brave challenge to a fundamental symmetry reshaped the field of...
The discovery of parity violation introduced asymmetry directly into our most fundamental laws. I will discuss how the conflict between symmetry and asymmetry has shaped where we are in fundamental physics and where we are going. Along the way we will check in on the discrete symmetries, the arrow of time and causality, work by T. D. Lee and G.C. Wick, Starobinsky inflation, etc..
Parity non-conservation provides a practical way to measure hyperon polarizations in high energy reaction experiments and leads to the discovery of significant transverse polarization of hyperons in unpolarized hadron-hadron collisions and a series of other unexpected spin effects. These striking spin effects lead to an active direction in QCD – the QCD spin physics.
Global polarization of...
This talk presents paradigm-changing studies of spin-entangled hyperons and antihyperons conducted at the BESIII experiment. Utilizing unique, high-statistics datasets of quantum-entangled pairs produced in electron-positron collisions, BESIII has established itself as a leading facility for precision hyperon physics. The core research focuses on the search for Charge-Parity (CP) violation in...
We discuss a two Higgs doublet model with successful electroweak baryogenesis but without cancellations of electric dipole moments (EDMs). For the baryogenesis, additional scalar bosons are favored to couple mainly with the top quark with CP violations. However, if they also couple to light fermions of the Standard Model, the model is limited severely by EDMs, and additional CP phases...
PandaX ( Particle and Astrophysical Xenon experiment), a large-scale liquid xenon dark matter detection project located at the China Jinping Underground Laboratory, has provided a high-sensitivity experimental platform for dark matter searches through the iterative development of three generations of detectors since its launch in 2009. It adopts the two-phase xenon time projection chamber...
Understanding the properties of quark matter and its phase structure is crucial for advancing our knowledge of the universe's evolution and the composition of visible matter. Over the past two decades, numerous experimental observations have provided evidence for the existence of strongly interacting quark-gluon plasma (sQGP) in relativistic heavy-ion collisions. As a result, exploring the QCD...
Measurements of parity-violating observables in electron scattering, atomic transitions, and electron-positron annihilation have played a decisive role in confirming and testing the Standard Model electroweak sector and in probing the strong interaction in the non-perturbative regime. After reviewing this story, I discuss the experimental frontier for parity-violation with electrons and the...
In November of 2011 LHCb announced the first evidence of CP violation in the charm sector. A nonzero value for the difference of CP asymmetries in the decays $D^0\to K^+K^-$ and $D^0\to\pi^+\pi^-$,
$\Delta A_{CP}=(-0.82\pm0.21\pm0.11)\%$
was reported. This had triggered a flurry of studies exploring whether this CP violation in the charm sector implies new physics. Direct CP violation (DCPV)...
The LHCb experiment at CERN’s Large Hadron Collider is dedicated to heavy-flavour physics, focusing on the decays of beauty and charm hadrons, with CP violation measurements among its core objectives. Since its inception, LHCb has advanced the study of CP violation into a precision era, achieving precise determinations of CKM phases and reporting the first observations of CP violation in the...
B physics plays a central role in the Belle and Belle II experimental programs, which operate at the (Super)KEKB asymmetric e^+ e^- collider. With a large recorded luminosity on the Υ(4S) resonance, Belle and Belle II provide a clean environment for studying B meson decays, CP violation, and rare processes. In this talk, I show some recent results of B physics at Belle II including measurement...
BESIII has accumulated 4.5fb-1 of e+e- collision data in the 4.6 and 4.7 GeV energy range, which provide the largest dataset of LcLc pairs in the world. We will present a novel way for exploring CP violation using the LcLc threshold data and the first observation of the transverse polarization of in the reaction e+e- -> LcLc. Furthermore, Our presentation will also include the observation of...
I discuss characteristic features of extra-dimensional axions arising from higher-dimensional gauge fields. Particular attention will be paid to the axion quality needed to solve the strong CP problem and to distinctive features of their low-energy couplings compared with conventional four-dimensional field-theoretic axions.
This talk is mainly based on the paper 2504.09218, a joint study with Sergei D. Odintsov.
We consider a pseudo-scalar quantity analogous to the Chern-Simons invariant within the framework of non-metric gravity.
By taking into account the coupling between this pseudoscalar and the axion, we present a scenario that may solve the axion misalignment problem, the S8 problem, and issues concerning...
James Webb Space Telescope (JWST) discovered remarkably numerous Little Red Dots (LRDs) in the Universe for a wide redshift z range from ~2 to ~7. Such LRDs, characterized by prominent V shaped continuum spectra with unusually broad Hα and Hβ lines (FWHM ~10^3 to ~10^4 km/s), are inferred to be extremely luminous, compact, massive, metal poor yet without detectable X-ray and radio emissions....
The muon anomalous magnetic moment, aμ=(g−2)μ/2, is one of the most sensitive precision observables for testing the Standard Model and probing new physics. The successive Muon g−2 experiments at CERN, Brookhaven, and Fermilab were recognized with the 2026 Breakthrough Prize in Fundamental Physics, reflecting the long-standing impact of this experimental program on precision tests of...
Hyperon decays serve as important windows for searching for new sources of CP violation and as ideal probes for studying strong interactions at low energies. In addition to the well-known hadronic weak decays of hyperons, this report presents an experimental overview of the weak radiative decays of hyperons, alongside the less-studied neutron-involved hyperon decays. These studies provide...
In this talk, I will report our progress on baryogenesis and phase transition.
I will talk about some recent flavor physics results from ATLAS and CMS, including the tetraquark search, excited Bc meson search, B meson lifetime measurements and time-dependent CPV measurements. These results deepen our understanding of particle physics in the flavor sector.
Precise measurements of Higgs decays into quarks and gluons are essential
for probing the Yukawa couplings of the Higgs boson and testing the flavor structure of the Standard Model. We investigate the process e+e− → ZH at √s = 240 GeV at a future e+e− Higgs factory, taking the CEPC design as a benchmark. Jet flavor is identified using state-of-the-art particle-level deep neural network...
Assuming the dark matter (DM) particle has hadronic interactions, we estimate the SN1987A limits on the effective hadronic DM couplings in the framework of dim-5 and dim-6 operators. The cross sections for the effective DM-nucleon couplings can be excluded up to $\sim10^{-52}\,{\rm cm}^2$ for DM mass down to the MeV scale, depending largely on the interaction type. We also update the supernova...
Neutron stars (NS's) with their strong magnetic fields and hot dense cores could be powerful probes of axions, a classic benchmark of feebly-coupled new particles, through abundant production of axions with the axion-nucleon coupling and subsequent conversion into X-rays due to the axion-photon coupling. In this article, we point out that the pulsation structures in both the intensity and...
This talk presents new perspectives on precision nucleon tomography using high-order QCD calculations and jet substructure. We discuss the winner-take-all axis for extending qT subtraction to jet processes, enabling NNNLO predictions for SIDIS and hadron production in DIS. Novel observables such as one-point energy correlators access the nucleon transversity distribution. Furthermore, we...
The chiral gravitational wave background (GWB) can be generated by axion‑like fields in the early universe. The conventional notion of an audible axion relies on couplings between axions and gauge fields. Here we consider an axion‑like mechanism coupled to the gravitational topological term, which enables direct and efficient production of gravitational waves during the radiation‑dominated era...
The $\mu$-$e$ conversion process is one of the most powerful ways to test lepton-flavor-violating (LFV) interactions involving charged leptons. The standard model with massive neutrinos predicts an extremely low rate for $\mu$-$e$ conversion, making this process an excellent probe for testing LFV arising from new physics. Among many theoretical models that can induce LFV, the Supersymmetric...
In this Letter, we present a strategy to decode decay amplitudes with different weak phases in two-body charmed baryon decays, addressing a long-standing challenge to understanding CP violation in this sector.
Using SU(3) flavor symmetry, we disentangle the amplitudes defined through $M=\lambda_s A_s + \lambda_b A_b$ ($\lambda_i = V_{ui}V_{ci}^*$), enabling a data-driven determination of...
We present a novel framework of the post-inflationary composite axion to address the strong CP problem without the cosmological domain wall problem. Conventional composite axion models lead to the domain wall number greater than one, producing stable axion domain walls that overclose the Universe. We show that by considering a special embedding of the confining gauge group responsible for the...
The precision determination of the leptonic CP-violating phase $\delta_{CP}$ is one of the main goals of the upcoming long-baseline experiments DUNE and Hyper-Kamiokande. Within the standard three-flavor framework and the usual assumptions on neutrino cross sections -- namely lepton universality and accurate nuclear modeling -- both experiments are projected to reach high sensitivity to...
In this talk, I will discuss about my recent work on the searches for the ultralight scalar dark matter with quadratic interactions with SM fields. This will lead to the effective interactions between the ultralight dark matter and the nucleon fields phi^2 N N/f below the QCD confinement scale, which can be thought as potential barrier for the dark matter wind in the presence of ordinary...
This talk presents a unified view of glueball dark matter and related composite states in confining dark Yang–Mills sectors. I first review lattice-informed effective descriptions of dark confinement and chiral dynamics, and show how the resulting phase transitions can generate potentially observable gravitational-wave signals, especially in fermionic and near-conformal regimes. I then discuss...
Motivated by the recent 3.9$\sigma$ evidence for CP violation from the LHCb collaboration in decays of an anti-triplet beauty baryon to a charmonium, an octet baryon, and a pseudoscalar meson,
we perform, for the first time, a systematic analysis of this class of decays within the framework of flavor $SU(3)$ symmetry.
Several predictions for branching ratios and CP violating relations...
We identify a new spin--flavor entanglement structure in $\Lambda_b\to\Lambda D$ decays, formed by the correlation between the $\Lambda$ spin and the neutral-$D$ flavor states ($D=D^0,\overline D^0,D_1,D_2$). The entanglement information is encoded in the decay rates and Lee-Yang parameters of the four neutral-$D$ modes. We then show that the same spin-flavor structure provides a new method...
The tRopIcal DEep-sea Neutrino Telescope (TRIDENT) project aims to pioneer the development of a next-generation deep-sea neutrino observatory. Designed to detect high-energy astrophysical neutrinos, TRIDENT seeks to address the century-old puzzle of the origin of cosmic rays. Furthermore, it will enable precise measurements of the flavor ratio of astrophysical neutrinos, providing valuable...
The discovery of parity violation marked a turning point in fundamental physics: it showed that nature distinguishes left from right, revealing the chiral structure of the weak interaction and paving the way to electroweak theory. This line of inquiry has continued through the discoveries of CP violation, electroweak unification, and the Higgs boson with its associated scalar interactions....
After reviewing the familiar definition of parity transformations and why they are explicitly broken in the standard model, I will discuss three ways that parity can be upgraded to being either a spontaneously broken or an exact symmetry. The resulting theories remain as interesting, aesthetically-driven speculations for physics beyond the standard model that can be searched for experimentally...
Parity conservation was first questioned along with some possible experimental tests suggested by TD Lee and CN Yang in 1956. In 1957, several experiments confirmed parity nonconservation in weak interaction. However, the theory of weak interaction: V-A theory was only established in 1958 by Marshak et al. The V-A chiral structure is encoded as the defining feature of the electroweak unified...
