Highlights
-
Tests of amorphous carbon-coated storage cells for a polarized gas target at LHCb and further results
2025, 49(8): 084002. doi: 10.1088/1674-1137/add70e
As the LHC beams cannot be polarized, introducing a dense polarized gas target at the LHCb experiment at CERN, to be operated concurrently with beam-beam collisions, will facilitate fixed-target interactions to explore a new energy regime of spin physics measurements. Unfortunately, typical surface coatings used to avoid polarization losses, such as water, Teflon, or aluminum, are prohibited due to restrictions imposed by vacuum and beam policies. The former atomic beam source for the polarized target at ANKE@COSY (Forschungszentrum Jülich), an accompanying Lamb-shift polarimeter, and a storage cell chamber inside a superconducting magnet provide a perfect test stand to investigate the properties of a storage cell coated with amorphous carbon. A significant recombination rate, ranging from 93% to 100%, and preservation of polarization during recombination surpassing 74% were observed. We successfully produced$ \mathrm{H}_2 $ molecules with a nuclear polarization of$ P\sim 0.59 $ . In addition, we could produce polarized$ \mathrm{H}_3^+ $ ions for the first time and observed the shift of the axis of rotation within$ \mathrm{HD} $ molecules. -
B(E2) anomaly and triaxial deformation within a two-fluid
${{\boldsymbol S} {\boldsymbol U} }$ (3) symmetry2025, 49(8): 084106. doi: 10.1088/1674-1137/adcd4a
The correlation between$ B(E2) $ structure and triaxial deformation has been investigated within the framework of the proton-neutron boson model. The analysis reveals that the distinctive feature, characterized by$ B(E2;4_1^+\rightarrow2_1^+)/B(E2;2_1^+\rightarrow0_1^+)<1.0 $ along with$ E(4_1^+)/E(2_1^+)>2.0 $ , can emerge from the triaxial$ S U$ (3) symmetry inherent in two-fluid boson systems, attributed to band-mixing effects. This suggests a symmetry-based understanding of the anomalous$ E2 $ transitions observed in experiments. -
Lepton-number-violating pion decay and type-I seesaw mechanism in chiral perturbation theory
2025, 49(8): 083103. doi: 10.1088/1674-1137/add5c6
We investigate the process of lepton-number-violating pion decay, which dominates the nuclear neutrinoless double beta decay induced by the short-range operator within the type-I seesaw mechanism. The type-I seesaw mechanism leads to the Dirac and Majorana mass terms of neutrinos by introducing the gauge-singlet right-handed neutrinos, which are often called sterile neutrinos. Applying the chiral perturbation theory, we calculate the transition amplitudes for light and heavy sterile neutrinos up to$ \mathcal{O}(Q^2/\Lambda^2_\chi) $ , where Q is the typical low-energy scale in this process and$ \Lambda_\chi $ the chiral symmetry breaking scale. We then adopt a naive interpolation formula of mass dependence to obtain the amplitude in the full mass range and briefly discuss its validity.
Just Accepted
More >
-
Radiation properties of the accretion disk around a quantum-corrected blackack holes
Published: 2025-09-07
-
Study the decays of χcJ(J = 0,1,2) to light meson pairs with SU(3) flavor symmetry/breaking analysis
Published: 2025-09-02
- Study the yrast and yrare low-lying excited states using machine learning approaches Bo Lan, Qin-Ze Song, Jin-Huan Sheng, Yi Qiao, Ru-Min Wang
Published: 2025-09-02
Recent
More >
-
Thermodynamic phase transition and Joule-Thomson expansion of a quantum corrected black hole in AdS spacetime
2025, 49(11): 115102-115102-13. doi: 10.1088/1674-1137/ade4a9Show AbstractThe thermodynamics in the extended phase space of a quantum corrected black hole (BH) proposed recently is presented in this paper. Our study shows that the phase transition behavior of the BH is analogous to that of a conventional Schwarzschild BH in anti-de Sitter (AdS) space; however, a critical temperature exists such that, when the BH temperature exceeds this critical value, the small and large BH phases become separated, and no phase transition occurs. Owing to the introduction of the quantum parameter ξ, the BH equation of state splits into two branches. One branch reduces to the Schwarzschild-AdS case as
$ \xi\to0$ , with its phase transition pressure lower than the critical pressure; the phase transition pressure in the other branch is greater than the critical pressure. This study shows that the$ T-r_{+}$ phase transition and heat capacity of the recently proposed BH are similar to those of the Schwarzschild-AdS BH. The Joule-Thomson expansion is divided into two stages: in the earlier stage, the BH pressure increases until it reaches a maximum; in the later stage, the pressure gradually decreases. In each stage, the BH may undergo an inversion point, resulting in an inversion curve with two branches. In addition, each stage has a minimum inversion mass, below which any BH (in each respective stage) has no inversion point. -
1+1 dimensional relativistic viscous non-resistive magnetohydrodynamics with longitudinal boost invariance
2025, 49(11): 114104-114104-13. doi: 10.1088/1674-1137/ade6d4Show AbstractWe study 1+1 dimensional relativistic non-resistive magnetohydrodynamics (MHD) with longitudinal boost invariance and a shear stress tensor. Several analytical solutions describing the fluid temperature evolution under a given equation of state (EoS)
$ \varepsilon=3p $ are derived. Extending the Victor-Bjorken ideal MHD flow to include non-zero shear viscosity, we first obtain two perturbative analytical solutions for the first-order (Navier-Stokes) approximation. For small, power-law evolving external magnetic fields, our stable solutions show that both magnetic field and shear viscosity cause fluid heating with an early temperature peak, consistent with numerical results. In the second-order (Israel-Stewart) theory, our numerical results show that the combined presence of magnetic field and shear viscosity leads to a slow cooling rate of fluid temperature, with initial shear stress significantly influencing temperature evolution of the medium. -
Stable circular orbits and greybody factor of Hayward-Letelier-AdS black holes
2025, 49(11): 115104-115104-17. doi: 10.1088/1674-1137/ade4a7Show AbstractThis paper explores the dynamical feature of Hayward-Letelier black holes in AdS spacetime, emphasizing the effects of the Hayward parameter g, mass M, cosmological constant L, and modification parameter α on their geometry, thermodynamics, and observational features. By utilizing an effective potential method, we investigate the paths of particles, innermost stable circular orbit, and behavior of photon spheres, which connects them to the appearance of black hole shadows. Thermodynamic features such as Hawking temperature and entropy are studied for investigating the effect of L and thermal fluctuations on the stability of black holes. These discoveries connect theoretical ideas with observational astrophysics, which enhances our comprehension of ordinary black holes in AdS models. In this study, we analytically compute the greybody factor for a massless scalar field propagating in the vicinity of a black hole under the assumption of weak coupling to gravity. We investigate the behavior of the effective potential concerning the black hole's mass and charge, revealing that it reaches its maximum at lower values of the cloud of strings parameter. Our results indicate that the radial absorption rate of the scalar field exhibits significant fluctuations, which is influenced by the charge of the black hole and clouds of string, with implications for the dynamics of scalar fields in strong gravitational fields.
Current Issued
2025 Vol. 49, No. 9
Published: 05 September 2025
Published: 05 September 2025
Archive
IF: 3.1
Monthly issued, founded in 1977
Sponsored by:
ISSN 1674-1137 CN 11-5641/O4
Original research articles, Ietters and reviews Covering theory and experiments in the fieids of
- Particle physics
- Nuclear physics
- Particle and nuclear astrophysics
- Cosmology
Author benefits
- A SCOAP3 participating journal - free Open Access publication for qualifying articles
- Average 24 days to first decision
- Fast-track publication for selected articles
- Subscriptions at over 3000 institutions worldwide
- Free English editing on all accepted articles
News
- Chinese Physics C Outstanding Reviewer Award 2023
- Impact factor of Chinese Physics C is 3.6 in 2022
- 2022 CPC Outstanding Reviewer Awards
- The 2023 Chinese New Year-Office closure
- 《Chinese Physics C》BEST PAPER AWARDS 2022
Cover Story
- Cover Story (Issue 1, 2025) Comments on Prediction of Energy Resolution inthe JUNO Experiment
- Cover Story (Issue 12, 2024) | Doubly heavy meson puzzle: precise prediction of the mass spectra and hadronic decay with coupled channel effects to hunt for beauty-charm family
- Cover Story (Issue 9, 2024) Measurement of solar pp neutrino flux using electron recoil data from PandaX-4T commissioning run
- Cover Story (Issue 11, 2024) ｜ Form factor for Dalitz decays from J/ψ to light pseudoscalars
- Cover Story (Issue 3, 2024) | First measurement of the ground-state mass of 22Al helps to evaluate the ab-initio theory
Advertising
