Chinese Physics C

2026-7 Contents

2026, 50(7): 1-2.

HTML

PDF

Abstract:

Sensitivity study of ${\bar{K}_1(1270)}$ decay dynamics using four ${D\to \bar{K}_1(1270)(\to \bar K\pi\pi)e^+\nu_e}$ decay channels

Ying'ao Tang, Liang Sun, Panting Ge, Menghao Wang

2026, 50(7): 073001. doi: 10.1088/1674-1137/ae5c70

HTML

PDF

Abstract:
A sensitivity study of

\begin{document}$ \bar{K}_1(1270) $\end{document}

decay-mode measurements is performed using semileptonic D-meson decays. The BESIII experiment is used as a case study, in which a simultaneous analysis of

\begin{document}$ \bar{K}_1(1270) $\end{document}

decays to the four three-body final states

\begin{document}$ K^-\pi^+\pi^- $\end{document}

,

\begin{document}$ K^-\pi^+\pi^0 $\end{document}

,

\begin{document}$ K_S^0\pi^+\pi^- $\end{document}

, and

\begin{document}$ K_S^0\pi^-\pi^0 $\end{document}

is presented, and a model-independent determination of

\begin{document}$ {\cal{B}}(\bar{K}_1(1270)\to \bar K\pi\pi) $\end{document}

that does not require detailed knowledge of intermediate resonant contributions is proposed.

Measurement of the neutron capture cross section using C₆D₆ detectors at the milli-barn scale: a case study of ²⁰⁹Bi

Jing Liu, Song Feng, Wei Jiang, Xinxiang Li, Min Xiao, Pinjing Cheng, Jieming Xue, Baoqian Li, Jirong Zhao, Luyan Tao, Peng Luan, Wenxin Huang, Youchun Xiao, Sijia Han, Cunzhi Deng, Shiqi Tang, Yixi Chen, Mengyan Wang, Shiqing Yuan, Bo Zheng

2026, 50(7): 073002. doi: 10.1088/1674-1137/ae5ef9

HTML

PDF

Abstract:
Accurate neutron capture cross section data are essential for validating nuclear models, understanding the origin of heavy elements, and improving reactor safety assessments. Measuring weakly absorbing nuclides at the milli-barn scale is challenging because of low-intensity signals, high levels of environmental background, and sensitivity to target impurities. To investigate the capability of

\begin{document}$\text{C}_6\text{D}_6$\end{document}

detectors for measuring the neutron capture cross sections at the milli-barn scale, an experiment on the

\begin{document}$^{209}$\end{document}

Bi

\begin{document}$(n, \gamma)$\end{document}

reaction was performed at the Back-n white neutron facility of the China Spallation Neutron Source (CSNS). The data were processed using the time-of-flight (TOF) method and the pulse-height weighting technique (PHWT). Because of the notably small capture cross section of

\begin{document}$^{209}$\end{document}

Bi and the complex background, the experimental results exhibited strong statistical fluctuations, making it difficult to identify resonance structures. To address this issue, the average capture cross section was determined by optimizing the energy binning. The reasons behind the resonance structures being obscured by the background were analyzed, and possible solutions were proposed. In this study, we provide valuable insights into the measurement of nuclides with low neutron capture cross sections using

\begin{document}$\text{C}_6\text{D}_6$\end{document}

detectors.

Enhanced evidence of X(7200) and improved measurements of X(6900) parameters from a combined LHCb-ATLAS-CMS analysis

Yuan Wang, Ran Li, Bin Zhong, Ya-Qian Wang

2026, 50(7): 073003. doi: 10.1088/1674-1137/ae643e

HTML

PDF

Abstract:
We report stronger evidence for the

\begin{document}$X(7200)$\end{document}

state and markedly improved measurements of the

\begin{document}$X(6900)$\end{document}

resonance parameters based on a combined analysis of the di-

\begin{document}$J/\psi$\end{document}

mass spectrum using published data from LHCb, ATLAS, and CMS. Through simultaneous fits to the datasets from all three experiments, we observe the

\begin{document}$X(6900)$\end{document}

with overwhelming significance (

\begin{document}$>12\sigma$\end{document}

) and determine its mass and width with improved precision. For the

\begin{document}$X(7200)$\end{document}

, we find consistent signals across multiple interference models, with significances ranging from

\begin{document}$3.7\sigma$\end{document}

to

\begin{document}$6.6\sigma$\end{document}

; in the best-fit model (the CMS three-resonance scheme), the significance reaches

\begin{document}$6.6\sigma$\end{document}

, providing substantially stronger evidence for this state. Our results underscore the essential role of interference effects in fully charmed tetraquark spectroscopy and offer new constraints on their production mechanisms at the LHC.

Relativistic corrections to hadron-hadron scattering phase shift and correlation function

Zeyu Zeng, Baoyi Chen, Jiaxing Zhao

2026, 50(7): 073101. doi: 10.1088/1674-1137/ae5884

HTML

PDF

Abstract:
Femtoscopy offers a sensitive probe of hadron emission sources and hadronic interactions. In this study, we examine relativistic corrections to scattering phase shifts and correlation functions using the two-body Dirac equation framework. We analyze the impact of the Darwin term and spin-dependent potentials, showing that these relativistic effects, especially spin-related interactions, significantly enhance the proton-proton correlation function. Our findings emphasize the necessity of including relativistic corrections for precise femtoscopic analyses.

Prospects for discovering strongly decaying doubly heavy T_bc tetraquark states at LHCb

Mingjie Feng, Yiming Li, Hua-Sheng Shao

2026, 50(7): 073102. doi: 10.1088/1674-1137/ae5a87

HTML

PDF

Abstract:
We investigate the discovery potential of the

\begin{document}$T_{bc}$\end{document}

state with

\begin{document}$J^P = 0^+$\end{document}

in proton-proton (

\begin{document}$pp$\end{document}

) collisions at LHCb at a center-of-mass energy of

\begin{document}$\sqrt{s} = 13~{\rm{TeV}}$\end{document}

. The study focuses on the decay channel

\begin{document}$T_{bc} \to B^- D^+$\end{document}

. A phenomenological approach is employed to construct the background model based on the associated production of B and D mesons, incorporating previously published LHCb results. Background processes are simulated using

\begin{document}${\mathtt{MadGraph5\_aMC@NLO}}$\end{document}

and

\begin{document}${\mathtt{Pythia8.3}}$\end{document}

. We explore the parameter space of the

\begin{document}$T_{bc}$\end{document}

mass, width, production cross section, and the effective double-parton scattering cross section (

\begin{document}$\sigma_{{\rm{eff}}}$\end{document}

) relevant for the

\begin{document}$B D$\end{document}

meson background. The integrated luminosity required for a

\begin{document}$5\sigma$\end{document}

discovery at LHCb is evaluated under various assumptions. In particular, we consider three representative

\begin{document}$T_{bc}$\end{document}

production cross section scenarios: an optimistic estimate of

\begin{document}$103~{\rm{nb}}$\end{document}

, an intermediate value of

\begin{document}$18~{\rm{nb}}$\end{document}

obtained by scaling from the

\begin{document}$T_{cc}^+$\end{document}

production cross section, and a conservative lower bound of

\begin{document}$0.3~{\rm{nb}}$\end{document}

. We find that a

\begin{document}$5\sigma$\end{document}

observation is achievable for a production cross section of

\begin{document}$103~{\rm{nb}}$\end{document}

, which is expected to be within reach during Run4. In contrast, the more realistic cross section estimate of

\begin{document}$18~{\rm{nb}}$\end{document}

requires the full Run5 dataset (

\begin{document}$300~{\rm{fb}}^{-1}$\end{document}

) under the most favorable parameter choices. For the conservative scenario, no significant signal would be observable even with

\begin{document}$300~{\rm{fb}}^{-1}$\end{document}

. In addition, we estimate the minimum observable

\begin{document}$\sigma(T_{bc}) \times {\cal{B}}(T_{bc} \to $\end{document}

\begin{document}$ B^- D^+)$\end{document}

for a

\begin{document}$5\sigma$\end{document}

discovery under different luminosity scenarios, providing guidance for future experimental searches at LHCb.

Searching the possibility of a₀(1450) scalar state being a qq state structure via charmed meson semileptonic decays

Ya-Lin Song, Yin-Long Yang, Ye Cao, Xue Zheng, Hai-Bing Fu

2026, 50(7): 073103. doi: 10.1088/1674-1137/ae5ef7

HTML

PDF

Abstract:
The internal structure of the light scalar state

\begin{document}$ a_0(1450) $\end{document}

has not been definitively determined; it may comprise multiple possible configurations. Among these, it may be regarded as a

\begin{document}$ q\bar{q} $\end{document}

state. Based on this possibility, we use QCD light-cone sum rules to study the semileptonic decay process

\begin{document}$ D \to a_0(1450)\ell \nu_\ell $\end{document}

with

\begin{document}$ \ell=(e, \mu) $\end{document}

and to test this hypothesis. First, we construct two twist-2 light-cone distribution-amplitude schemes based on the light-cone harmonic-oscillator model, and present their moments

\begin{document}$ \langle\xi^{n}\rangle |_{\mu} $\end{document}

and Gegenbauer moments

\begin{document}$ a_{n}(\mu) $\end{document}

at

\begin{document}$ \mu_0=1\; {\rm{GeV}} $\end{document}

and

\begin{document}$ \mu_k= 1.4\; {\rm{GeV}} $\end{document}

for

\begin{document}$ n=(1,3,5) $\end{document}

. In the large-recoil region, we obtain the transition form factors (TFFs):

\begin{document}$ f_+^{({\rm{S}}1)}(0) = $\end{document}

\begin{document}$ 0.836_{-0.119}^{+0.116} $\end{document}

,

\begin{document}$ f_+^{({\rm{S}}2)}(0)=0.767_{-0.105}^{+0.106} $\end{document}

, and

\begin{document}$ f_-(0)=0.630_{-0.077}^{+0.078} $\end{document}

. A simplified series expansion

\begin{document}$ z(q^2, t) $\end{document}

is used to extrapolate the TFFs to the entire physical

\begin{document}$ q^2 $\end{document}

region. For

\begin{document}$ q^2=10^{-5} \; {\rm{GeV}}^2 $\end{document}

, we compute the angular distribution of the differential decay width

\begin{document}${{\rm d}\Gamma}/{{\rm d}\cos\theta_\ell }$\end{document}

over the range

\begin{document}$ \cos\theta_\ell \in [-1,1] $\end{document}

. Subsequently, we obtain the differential decay widths and branching fractions for

\begin{document}$ D^0 \to a_0(1450)^- \ell^+ \nu_\ell $\end{document}

and

\begin{document}$ D^- \to a_0(1450)^0 \ell^- \bar{\nu}_\ell $\end{document}

, with branching fractions of order

\begin{document}$ 10^{-6} $\end{document}

. Finally, we analyze three angular observables for the semileptonic decay process

\begin{document}$ D^- \to a_0(1450)^0 \ell^- \bar{\nu}_\ell $\end{document}

: the forward–backward asymmetry

\begin{document}$ {\cal{A}}_{\rm{FB}} $\end{document}

, the lepton polarization asymmetry

\begin{document}$ {\cal{A}}_{\lambda_\ell} $\end{document}

, and the

\begin{document}$ q^2 $\end{document}

-differential flat term

\begin{document}$ {\cal{F}}_{\rm{H}} $\end{document}

.

Neutrino tomography with a three-dimensional model of Earth's density

Jiayi Wei, Junhui Xing, Sujie Lin, Xiurong Li, Jiwei Tian

2026, 50(7): 073104. doi: 10.1088/1674-1137/ae5c85

HTML

PDF

Abstract:
Neutrino Earth tomography provides an observational approach to studying the Earth's deep three-dimensional structure that is distinct from seismology. However, most existing studies still rely on one-dimensional density models and therefore cannot adequately represent lateral heterogeneity within the Earth. To address this issue, this study integrates PREM, CRUST1.0, and HMSL-S06 on a tesseroid grid to construct a non-spherically symmetric three-dimensional Earth density model that includes large low-velocity provinces (LLVPs) in the deep mantle. We also develop a corresponding procedure for extracting neutrino propagation trajectories and derive closed-form expressions for the total mass and axial moment of inertia of the discrete model, which are used as global consistency checks. Within an exact three-flavor oscillation framework, we use public Super-Kamiokande data products to compare the event counts predicted by the three-dimensional model with those from a conventional one-dimensional spherically symmetric model. The results show that, under the present calculation scheme, the differences in the overall event count distributions between the three-dimensional model and the one-dimensional reference model remain limited. This study establishes a three-dimensional calculation framework that can provide a methodological basis for future investigations of how lateral density heterogeneity may affect atmospheric neutrino propagation.

Analysis of molecular state η_cD^* and J/ψD^* in the effective Lagrangian approach

Na Li, Ye Xing, Jing-Rui Shi

2026, 50(7): 073105. doi: 10.1088/1674-1137/ae5f08

HTML

PDF

Abstract:
In this work, we investigate the production and decay of molecular states with quark content

\begin{document}$cc\bar c\bar q$\end{document}

and

\begin{document}$J^P=1^+$\end{document}

using a phenomenological analysis and an effective Lagrangian approach. Based on an SU(3) flavor-symmetry analysis to identify golden channels, we further explore the dynamics of these processes under the molecular assumptions of

\begin{document}${\eta_c D^*}$\end{document}

and

\begin{document}${J/\psi D^*}$\end{document}

. Our results indicate that the production branching ratio in

\begin{document}$B_c$\end{document}

decays is sizable: it can be of order

\begin{document}$10^{-4}$\end{document}

for the molecular configuration

\begin{document}${{\eta}_cD^*}$\end{document}

and

\begin{document}$10^{-5}$\end{document}

for the molecule

\begin{document}${J/\psi D^*}$\end{document}

. In addition, we find that the decay widths of the two molecular configurations

\begin{document}${{\eta}_cD^*}$\end{document}

and

\begin{document}${J/\psi D^*}$\end{document}

are not significant, at the level of

\begin{document}${\cal{O}}$\end{document}

(

\begin{document}$\text{MeV}$\end{document}

).

Testing a linear relation: short-range correlations and the EMC effect for gluons and quarks in nuclei

Shu-Man Hu, Wei Wang, Ji Xu, Xing-Hua Yang, Shuai Zhao

2026, 50(7): 073106. doi: 10.1088/1674-1137/ae62f8

HTML

PDF

Abstract:
In this work, we focus on the possible linear relationship between short-range correlations (SRCs) and the EMC effect for partons in nuclei. First, we test a linear relationship pertaining to gluons in bound nuclei; it is manifested as a correlation between the slope of the reduced cross-section ratio in deep inelastic scattering (DIS) and the cross-section of sub-threshold

\begin{document}$ J/\psi $\end{document}

photoproduction. For comparison, results from four different global analysis groups of nuclear parton distribution functions (nPDFs) are utilized. These results show a good linear correlation between the gluons in bound nuclei and the slope of the reduced cross-section ratio, consistent with the possible presence of nuclear effects in the gluon distributions. Second, we investigate the linear relationship of quarks in the proton-induced Drell-Yan process. The corresponding results for quarks show strong sensitivity to the parameterizations forms adopted by the different groups. These findings enhance our understanding of the substructure in bound nuclei and provide a valuable reference for future global fitting of nPDFs.

Neutral scalar pair production via W-boson fusion at multi–TeV muon colliders

Khiem Hong Phan, Quang Hoang-Minh Pham

2026, 50(7): 073107. doi: 10.1088/1674-1137/ae62fa

HTML

PDF

Abstract:
In this work, we present the first computation of the full one-loop electroweak radiative corrections to the process

\begin{document}$ \mu^- \mu^+ \to W^\pm W^\mp \to hh $\end{document}

within the Standard Model (SM). Building upon this, we investigate neutral scalar pair production via vector boson fusion at multi–TeV muon colliders in the framework of the Two-Higgs-Doublet Model (2HDM). In our phenomenological analysis, we introduce an enhancement factor, defined as the ratio of the cross section for SM-like Higgs pair production in the 2HDM to the corresponding SM prediction. This factor is systematically evaluated across the allowed regions of parameter space in both Type-X and Type-Y 2HDMs. Our results indicate that, within the viable Type-X parameter space, this factor can reach a value of 3, whereas it remains between 0.91 and 0.95 across the allowed parameter space of the Type-Y scenario. We observe that the enhancement factor exhibits distinct behaviors in the Type-X and Type-Y 2HDMs. This feature provides a promising opportunity to discriminate between the two scenarios through precision measurements of double Higgs production at future multi–TeV colliders. Furthermore, we perform a detailed scan of the cross sections for both CP-odd and CP-even Higgs pair production over the viable parameter spaces of the Type-X and Type-Y 2HDMs. In the Type-Y scenario, at a center-of-mass (CoM) energy

\begin{document}$ \sqrt{s} = 10\; \text{TeV} $\end{document}

and an integrated luminosity of

\begin{document}$ {\cal{L}} = 10000\; \text{fb}^{-1} $\end{document}

, both CP-odd and CP-even Higgs pair production in the

\begin{document}$ t\bar{t}b\bar{b} $\end{document}

final state, with subsequent top-quark decays into leptons and bottom quarks, can be probed with a statistical significance exceeding the

\begin{document}$ 2\sigma $\end{document}

level at several viable parameter points.

Holographic QCD equation of state constrained by lattice QCD: neural-ODE for probe-limit and a back-reaction test

Yutian Deng, Mei Huang, Lin Zhang

2026, 50(7): 073108. doi: 10.1088/1674-1137/ae62fc

HTML

PDF

Abstract:
We study the equation of state (EoS) of QCD matter in a bottom-up holographic setup that combines an Einstein-Maxwell-dilaton (EMD) sector with an improved Karch-Katz-Son-Stephanov (KKSS) flavor action. In the probe approximation, we perform an inverse reconstruction of the model functions by parameterizing them with neural networks and solving the EMD equations via a differentiable ODE solver (a neural ODE framework), calibrating the model to a reference thermodynamic table for

\begin{document}$(2+1)$\end{document}

-flavor QCD at finite temperature and finite baryon chemical potential. The reconstructed model functions are then parameterized and kept fixed across thermodynamic states. Next, viewing the EMD sector as an effective description of pure Yang-Mills theory, we fix its parameters by fitting the

\begin{document}$\mu_B=0$\end{document}

lattice pure-glue EoS using a hybrid optimization strategy. Finally, we go beyond the probe limit and solve the coupled EMD+KKSS equations with back-reaction, using the pure-glue-calibrated EMD sector as a fixed input and varying the KKSS couplings to compare with the

\begin{document}$\mu_B=0$\end{document}

two-flavor lattice EoS. We find a visible mismatch and a high-temperature behavior in which the back-reacted dimensionless ratios approach a nearly

\begin{document}$\beta_1$\end{document}

-insensitive plateau close to the pure-glue baseline, providing a simple structural diagnostic for the present flavor-sector truncation.

Higgs Bosons at 95 and 125 GeV in the U(1)_X VLFM

Rong-Zhi Sun, Shu-Min Zhao, Meng-Zi Cao, Song Gao, Xing-Xing Dong

2026, 50(7): 073109. doi: 10.1088/1674-1137/ae5ef8

HTML

PDF

Abstract:
We present a systematic analysis of the Higgs signal strengths at 125 GeV and 95 GeV in a non-supersymmetric

\begin{document}$ U(1)_X $\end{document}

model with vector-like fermions (

\begin{document}$ U(1)_X $\end{document}

VLFM). This framework extends the Standard Model (SM) by introducing an additional

\begin{document}$ U(1)_X $\end{document}

gauge symmetry, three right-handed neutrinos, two singlet Higgs fields (ϕ and S), and one generation of vector-like quarks and leptons. The scalar fields mix in the neutral CP-even sector, yielding two Higgs-like states around 95 GeV and 125 GeV. We perform a

\begin{document}$ \chi^2 $\end{document}

analysis that combines the Higgs signal strength measurements at 125 GeV from ATLAS and CMS, including the

\begin{document}$ \gamma\gamma $\end{document}

,

\begin{document}$ WW^* $\end{document}

,

\begin{document}$ ZZ^* $\end{document}

,

\begin{document}$ b\bar{b} $\end{document}

, and

\begin{document}$ \tau\bar{\tau} $\end{document}

channels, together with the 95 GeV excesses observed in the diphoton and

\begin{document}$ b\bar{b} $\end{document}

final states reported by CMS and LEP. Our results indicate that the

\begin{document}$ U(1)_X $\end{document}

VLFM successfully reproduces the observed signal strengths of the 125 GeV Higgs while simultaneously explaining the 95 GeV excess. The parameters

\begin{document}$ g_X $\end{document}

,

\begin{document}$ g_{YX} $\end{document}

,

\begin{document}$ v_S $\end{document}

,

\begin{document}$ v_P $\end{document}

, and the new Yukawa couplings play a crucial role in achieving this consistency.

Semileptonic ${B^{-}\to\pi^{+}\pi^{-}\ell^{-}\bar\nu_\ell}$ decay over the full ${\pi\pi}$ invariant mass spectrum

Yan-Li Wang, Xiao-Yu Hao, Yu-Kuo Hsiao

2026, 50(7): 073110. doi: 10.1088/1674-1137/ae68ee

HTML

PDF

Abstract:
The Belle Collaboration has recently reported a measurement of the branching fraction for the semileptonic decay

\begin{document}$ B^{-}\to\pi^{+}\pi^{-}\ell^{-}\bar\nu_\ell $\end{document}

, with

\begin{document}$ \ell=e $\end{document}

or μ. Using the newly available data across the full

\begin{document}$ \pi\pi $\end{document}

invariant-mass spectrum, we determine the non-resonant

\begin{document}$ B\to\pi\pi $\end{document}

transition form factors. We obtain a non-resonant branching fraction

\begin{document}$ {\cal B}_N(B^{-}\to\pi^{+}\pi^{-}\ell^{-}\bar\nu_\ell)=(3.5\pm 1.4^{+4.3}_{-2.4})\times 10^{-5} $\end{document}

. This result indicates that the non-resonant contribution can be comparable in magnitude to the resonant components and should not be treated as a negligible background in precision measurements. Our findings highlight the importance of dedicated experimental efforts at Belle II and LHCb to further probe the non-resonant contribution.

Symmetry-breaking effects on form factors and observables in B → K₀^*(1430)μ⁺μ^– decay

Saba Ayub, Saba Shafaq, Arslan Sikandar, M. Jamil Aslam

2026, 50(7): 073111. doi: 10.1088/1674-1137/ae6b23

HTML

PDF

Abstract:
In the heavy-quark and large-energy limits, symmetry relations reduce the number of independent form factors governing heavy-to-light B-meson decays. Exploiting these relations, the form factors can be parametrized while systematically incorporating symmetry-breaking corrections from perturbative QCD. Using vertex renormalization together with light-cone distribution amplitudes, we compute the vertex and hard-spectator contributions for the

\begin{document}$B \to K_0^{*}(1430)$\end{document}

transition. We then analyze the impact of these form factors on physical observables, including the branching ratio and lepton polarization asymmetries

\begin{document}$(P_L, P_N)$\end{document}

, in

\begin{document}$B \to K_0^{*}(1430)\mu^+\mu^-$\end{document}

. Our results indicate that perturbative corrections induce modest shifts of ~ 3% in both the branching ratio and the normal lepton polarization asymmetry. Consequently, any significant deviation observed experimentally from these predictions would provide a clear signal of potential New Physics effects.

Effective field theory description of light dilaton

Qing-Hong Cao, Jian-Nan Ding, Bing-Hui Ge, Hao Sun, Jiang-Hao Yu

2026, 50(7): 073112. doi: 10.1088/1674-1137/ae6da0

HTML

PDF

Abstract:
Dilatons, the CP-even pseudo-Nambu-Goldstone bosons arising from spontaneous scale symmetry breaking, offer a compelling alternative to axion-like particles (ALPs) yet lack a comprehensive low-energy framework. We address this by constructing a systematic effective field theory (EFT) for the dilaton based on a manifestly scale-invariant regularization scheme. This approach derives universal linear couplings to the trace anomaly while preserving consistent renormalization group evolution. We establish a hierarchical EFT tower connecting the ultraviolet conformal sector to the infrared, encompassing the dilaton-extended SMEFT, low-energy EFT up to dimension-7, and a chiral Lagrangian describing meson and baryon interactions. We perform a comprehensive phenomenological analysis across two distinct mass regimes, where the dilaton manifests as either a conventional particle or a wave-like particle. For MeV-scale dilatons behaving as conventional particles, we obtain constraints from LHC production, semi-invisible B- and K-meson decays, and supernova cooling. For ultralight dilatons acting as dark matter, we project sensitivities for atomic clocks and atom interferometers. This unified EFT framework would pave the way for extended phenomenological studies across the full mass spectrum of the light dilaton.

Measurement of differential and angle-integrated cross sections for the ¹⁰B(n, α)⁷Li reaction from 0.3 eV to 3.0 MeV at CSNS Back-n

Wenkai Ren, Han Yi, Haofan Bai, Jie Liu, Kang Sun, Wei Jiang, Zepeng Wu, Cong Xia, Guohui Zhang, Yonghao Chen, Ruirui Fan, Qiwen Fan, Shixiang Peng, Wentian Cao, Tieshuan Fan

2026, 50(7): 074001. doi: 10.1088/1674-1137/ae5dae

HTML

PDF

Abstract:
In the present study, new measurements of differential and angle-integrated cross sections for the ¹⁰B(n, α₁)⁷Li^*, ¹⁰B(n, α₀)⁷Li, and ¹⁰B(n, α)⁷Li reactions were performed at the CSNS Back-n white neutron source. The Light-charged Particle Detector Array (LPDA) system was used to detect charged particles. The ⁶Li-Si monitor was employed to measure the neutron flux. The differential cross sections for the ¹⁰B(n, α)⁷Li reaction were obtained from 20.1° to 158.3° (13 angles) in the neutron energy region from 0.3 eV to 3.0 MeV (70 energy points). The differential cross sections for the ¹⁰B(n, α₀)⁷Li and ¹⁰B(n, α₁)⁷Li^* reactions were also obtained at the same angular positions in the neutron energy region from 0.3 eV to 1.0 MeV (65 energy points). Fitting with the Legendre polynomial series, the angle-integrated cross sections of these three reactions were obtained through integration. The experimental data for these three reactions across such a wide neutron energy range are valuable references for future nuclear data evaluations.

New evaluation and validation toward neutron reaction data on chromium isotopes at incident energies below 200 MeV

Wen-Ye Wang, Yin-Lu Han, Ji-Min Wang, Huan-Yu Zhang, Yuan Tian, Xi Tao, Hai-Cheng Wu, Yong-Li Jin, Bo-Yu Tan, Yue Zhang, Zhao-Hui Wang, Zhi-Gang Ge, Rui-Rui Xu

2026, 50(7): 074101. doi: 10.1088/1674-1137/ae5807

HTML

PDF

Abstract:
Chromium (Cr) serves as an indispensable structural material in accelerator-driven systems (ADSs) and Generation IV reactors, where the precision of its neutron reaction data is important for ensuring reactor safety and operational reliability. However, significant discrepancies persist in both experimental data and evaluations for key reaction channels, such as

\begin{document}$(n, p)$\end{document}

and

\begin{document}$(n, 2n)$\end{document}

, across the chromium isotopes

\begin{document}${}^{50,52,53,54}{\rm{Cr}}$\end{document}

. This paper presents a novel evaluation and validation of neutron reaction data for these isotopes at incident energies below 200 MeV, incorporating 571 experimental datasets from EXFOR covering cross sections, angular distributions, energy spectra, and double - differential cross sections. The newly evaluated data provide more reliable key cross sections: the

\begin{document}${}^{52}{\rm{Cr}}(n,2n)$\end{document}

cross section resolves discrepancies and supports the data of Liskien et al.; the

\begin{document}${}^{52}{\rm{Cr}}(n, p)$\end{document}

cross-section aligns well with natural chromium data across all energies and is validated by competition analysis. The results accurately replicate double differential cross sections and energy spectra, with neutron emission spectra matching experimental peaks and charged - particle spectra agreeing with measurements for

\begin{document}${}^{50,52}{\rm{Cr}}$\end{document}

. Moreover, the abundance - weighted sum of

\begin{document}$(n, p)$\end{document}

and

\begin{document}$(n, 2n)$\end{document}

cross sections for chromium isotopes agrees well with natural chromium data, confirming systematic consistency. All evaluations are validated using 62 ICSBEP 2014 benchmark facilities with

\begin{document}$ k_{{\rm{eff}}}$\end{document}

sensitivity to chromium neutron data > 1%. For the PMI002_01 experiment, the calculated

\begin{document}$ k_{{\rm{eff}}}$\end{document}

value decreased by

\begin{document}$\sim 1000$\end{document}

pcm relative to the CENDL - 3.2 results, improving agreement with the benchmark; in the OKTAVIAN shielding benchmark, the neutron leakage spectrum also reproduced experiments well.

Research on the contribution of s-process to the abundance of ⁹⁴Mo

Chao Dong, Zhi-Hong Li, Ge-Xing Li, Yun-Ju Li, Na Song, Chen Chen, Jun-Wen Tian, Jia-Ying-Hao Li, Zhi-Cheng Zhang, Hui-Ling Tian, Mei-Yue-Nan Ma

2026, 50(7): 074102. doi: 10.1088/1674-1137/ae5ef4

HTML

PDF

Abstract:
This paper addresses a long-standing problem in astrophysics—the origin of the solar system abundance of the proton-rich isotope