Conveners
Fundamental symmetries and spin physics beyond the standard model: 02
- Bin Yan (IHEP)
- Peng Sun (IMP, CAS)
Fundamental symmetries and spin physics beyond the standard model: 03
- Liuming Liu (Institute of Modern Physics, CAS)
- Jian Liang (华南师范大学)
Description
Conveners: Xu Feng
With the largest datasets on $e^+ e^-$ annihilation at the $J/\psi$ and $\psi(3686)$ resonances collected at the BESIII experiment, multi-dimensional analyses making use of spin polarization and entanglement can shed new light on the production and decay properties of hyperon-antihyperon pairs. In a series of recent studies performed at BESIII, significant transverse spin polarization of the...
The violation of the charge-parity (CP) transformation symmetry, which although has been observed in plenty of pure meson decay processes, was only confirmed just very recently by the LHCb collaboration in the four-body decay of the heavy baryon $\Lambda_b^0$, $\Lambda_b^0\to p K^- \pi^+ \pi ^-$, through a comparison of the decay branching ratio with that of the CP-conjugate process. However,...
Spin correlations between particles produced at colliders provide valuable insights for quantum information studies. While traditional studies of quantum information at colliders are typically limited to massive particles with perturbative decay, we propose an innovative method to explore the Bell inequality in massless quark pair systems by analyzing the azimuthal correlations in $\pi^+\pi^-$...
We propose a novel series of methods to investigate light-quark dipole interactions at colliders. These methods include: (1) utilizing the azimuthal asymmetry of a collinear dihadron pair $(h_1h_2)$ produced in association with an additional hadron $h'$ at lepton colliders; (2) examining the azimuthal asymmetries of a collinear dihadron in semi-inclusive deep inelastic lepton scattering off an...
The dominance of matter over antimatter in the universe remains one of the key unresolved questions in modern physics. According to the Sakharov conditions, this asymmetry requires a violation of CP symmetry. While the Standard Model includes CP-violating effects, they are insufficient to account for the observed imbalance. A promising candidate for additional sources of CP violation is the...
We present a comprehensive investigation into the anomalous magnetic dipole moment ($a_\tau$) and electric dipole moment ($d_\tau$) of the $\tau$ lepton using the $\gamma\gamma \to \tau^+\tau^-$ process at future lepton colliders, with the Super Tau-Charm Facility serving as a benchmark. By employing transverse-momentum-dependent factorization, we introduce novel observables derived from...
The total cross section of the interaction of transversaly polarized ($P_y$) proton ($^3$He or deuteron) with the tenzor polarized ($P_{xz}$) deuteron constitues a null-test signal of time-reversal invariance violation under parity conservation (TVPC) in such processes (see Ref. [1] and references therein). This result follows from the optical theorem providing this signal for such...
Time reversal symmetry has long been a subject of interest from pre-modern physics time, since it implies the reversibility of motion. In the K^+→π^0 μ^+ ν (K_μ3) decay, the transverse muon polarization (P_T) is defined as the polarization component perpendicular to the decay plane. A non-vanishing value of P_T provides clear evidence for T-violation under the condition that spurious effects...
The CP violation beyond the standard model is not only physically interesting on its own, but also a key for understanding the baryon asymmetry in the current universe. In a low energy region, instead of directly probing it, many efforts to search the violation of time-reversal symmetry(T-violation) continue in various physics systems with high sensitivity. Among those, neutron-induced...
We report our lattice QCD calculation of the nucleon electric dipole moment (EDM) induced by the theta term. We use lattice chiral fermions in our calculation, which provides a fermionic definition of the topological charge exhibiting small discrete effects. Also, the use of chiral fermions guarantees a correct chiral limit even at finite lattice spacings and enables us to reliably extrapolate...
Using the anisotropic relativistic fermion action on isotropic lattice, we present a systematic study of the masses and lepton decay constants of the mesons with the bottom quark based on the 2+1 flavor tadpole improved clover ensembles at six different lattice spacings from 0.05 to 0.11 fm, various pion masses from 130 to 360 MeV, and several values of the strange quark mass. We also propose...
In this talk, we propose nucleon energy correlators (NECs) as a novel framework to probe electroweak light-quark dipole operators in unpolarized deep-inelastic scattering. These operators encode chirality-flipping interactions and typically appear quadratically in unpolarized processes. We construct a chiral-odd quark NEC that accesses quark transverse spin via azimuthal asymmetries in the...
The study of the charmed baryons is crucial for investigating the strong and weak interactions in the Standard Model and for gaining insights into the internal structure of baryons. In an $e^{+} e^{-}$ experiment the lightest charmed baryon, $\Lambda_c^{+}$, can be produced in pairs through the single photon annihilation process. This process can be described by two complex electromagnetic...
New interactions mediated by novel particles propose solutions to several important questions in modern physics.
Axions serve as examples of such particles; they are lightweight and interact weakly with ordinary matter.
This category of particles, including those similar to axions—termed Axion-Like Particles (ALPs)—emerges from diverse theoretical frameworks, including the Peccei-Quinn...
Time reversal symmetry has long been a subject of interest from pre-modern physics time, since it implies the reversibility of motion. In the K^+→π^0 μ^+ ν (K_μ3) decay, the transverse muon polarization (P_T) is defined as the polarization component perpendicular to the decay plane. A non-vanishing value of P_T provide clear evidence for T-violation under the condition that spurious effects...
We present a detailed spin-parity analysis of near-threshold structures in the fully-charm tetraquark sector, using a matrix-element-based approach applied to the J/\psi J/\psi \rightarrow 4\mu final state. Based on the full Run-2 dataset from the CMS experiment, multiple J^P hypotheses are tested using kinematic distributions of the four-muon system. A set of spin-parity combinations, J^P =...
In high-energy physics, traditional spin-orbit (L-S) decomposition effectively describes 3-point interaction structures and fully characterizes 3-point kinematics. However, its formulation is entirely dependent on the Center-of-Mass Frame (CMF) angular variables $(\theta,\varphi)$, necessitating Lorentz boosts back to the CMF for decomposition in practical calculations, which adds complexity....
