arXiv subjects

Hua Zheng

Publications and source records attributed to Hua Zheng.

At least 37 records · Page 2Linked to original sources

arXiv2025

Inclusive $J/ψ$ productions in pp collisions at $\sqrt{s}=$ 5.02, 7, and 13 TeV with the PACIAE model

We investigate the inclusive $J/ψ$ production in proton-proton (pp) collisions at center-of-mass energies $\sqrt{s} = 5.02$, 7, and 13 TeV using the PACIAE 4.0 model. This model extends PYTHIA 8.3 by incorporating partonic and hadronic rescatterings before and after hadronization, respectively. Compared to our earlier study [K.-F. Ye et al., Phys. Rev. C 109, 035201 (2024)], which considered only the color-singlet processes, the present work includes both the color-singlet and color-octet contributions within the non-relativistic QCD (NRQCD) framework. In addition to NRQCD, we also consider the contributions from the cluster collapse and weak decays of $b$-hadrons. We find that the simulated inclusive $J/ψ$ transverse momentum differential cross sections agree well with the experimental data at both the middle and forward rapidities. We provide a quantitative analysis of the relative contributions for different production mechanisms and their energy and rapidity dependence in the inclusive $J/ψ$ production. Furthermore, we offer a quantification of the relative contributions of the various components and their energy and rapidity dependence in the NRQCD channels, including the direct production via the hard scattering and the feed-down from the decays of heavier charmonium states such as $ψ(2S)$, $χ_{c0}$, $χ_{c1}$, and $χ_{c2}$. Finally, we examine the effects of partonic and hadronic rescatterings and offer the quantitative estimate of their impact on the $J/ψ$ production. These results are entirely new and represent a significant step forward in understanding the mechanisms of the inclusive $J/ψ$ production in high-energy pp collisions.

hep-ph↗

arXiv2025

Investigation of $T_{cs0}^{*}(2870)^{0}$ in $pp$ collisions at $\sqrt{s}$ = 7 TeV with the PACIAE model

We have used the parton and hadron cascade model PACIAE together with the Dynamically Constrained Phase-space Coalescence model (DCPC) to study the $T_{cs0}^{*}(2870)^{0}$ production in $pp$ collision at $\sqrt{s}$ = 7 TeV, following the LHCb observation of $T_{cs0}^{*}(2870)^{0}$ in the $B^{-}\to D^{-}D^{0}K^{0}_{S}$ decays in $pp$ collisions at $\sqrt{s}$ = 7, 8, and 13 TeV [PRL 134(2025)101901]. The final hadronic states of the $pp$ collisions at $\sqrt{s}$ = 7 TeV are first simulated by the PACIAE model. Four sets of $T_{cs0}^{*}(2870)^{0}$ candidates are then recombined by the DCPC model using the constituent meson pair of $D^{0}K^{0}_{S}$, $D^{+}K^{-}$, $D^{*+}K^{*-}$, and $D^{*0} \bar{K}^{*0}$ based on the above simulated final hadronic states, respectively. We calculate their rapidity distributions, transverse momentum spectra, and angular distribution between the two component mesons, as well as angular distribution between $D$ component meson and $T_{cs0}^{*}(2870)^{0}$. Our results show that the yields of four $T_{cs0}^{*}(2870)^{0}$ candidates follow the magnitude order of $D^{0}K^{0}_{S}$ $>$ $D^{+}K^{-}$ $>$ $D^{*+}K^{*-}$ $\sim$ $D^{*0} \bar{K}^{*0}$. Similar ordering behavior is also observed in the aforementioned distributions.

hep-ph↗

arXiv2025

A Classical Interpretation of the Nonrelativistic Quark Potential Model: Color Charge Definition and the Meson Mass-Radius Relationship

Quantum Chromodynamics (QCD) is the fundamental theory describing quark interactions, and various quark models based on QCD have been widely used to study the properties of hadrons, including their structures and mass spectra. However, unlike Quantum Electrodynamics (QED) and the Bohr model of the hydrogen atom, there is no direct classical analogy for hadronic structures.This paper presents a classical interpretation of the nonrelativistic quark potential model, providing a more intuitive and visualizable description of strong interactions through the quantitative formulation of color charge and color flux.Furthermore, we establish the relationship between meson mass and its structural radius in the nonrelativistic framework and estimate the key parameters of our model using available data from $η_b(1S)$ and $Υ(1S)$. We then extend this relationship to a broader range of excited meson states, obtaining structural radii that show good agreement with the root mean square (RMS) radius or charge radius predicted by QCD calculations.

hep-ph↗

arXiv2025

QCD phase transition at finite temperature and chemical potential with the non-extensive statistics

The intrinsic fluctuations, memory effects and long-range color interactions in high energy nuclear collisions imply the presence of non-Markovian processes in the fireball evolution, which affects the thermalization process towards equilibrium and produces a non-extensive behavior. In order to investigate the non-equilibrium effect on the quantum chromodynamics (QCD) phase transition at finite temperature ($T$) and chemical potential ($μ$), we apply a non-extensive correction to the equation of state in the parton (hadron resonance) gas at high (low) temperature and interpolate these two equation of states with a smooth crossover. The non-extensive statistics is characterized by a non-extensivity parameter $q$, which measures the degrees of deviation from the thermal equilibrium. It is found that the dimensionless thermodynamic quantities such as the entropy density, the pressure, the energy density, the specific heat at constant volume and the trace anomaly are sensitive to the deviation of $q$ from unity and they become large both in the hadronic and quark-gluon plasma phases with the increase of $q$. Moreover, this deviation leads to nontrivial corrections of the squared speed of sound ($(c_s^2)_q$) in the vicinity of the critical point ($T_c$) and at lower temperatures. Additionally, these thermodynamic quantities are sensitive to the deviation of $μ$ from zero. With increasing $μ$, they become enhanced in both phases. Specifically, for $(c_s^2)_q$, the value increases near $T_c$ but decreases at lower temperatures. Finally, we observe that our results with $q=1$ agree well with those from the Lattice QCD, the hadron resonance gas model, and the Thermal-Fist fit to the hadron yields in high energy nuclear collisions in the low temperature region up to $T\sim 150$ MeV.

hep-ph↗

arXiv2025

Strangeness production in $p$Pb collisions at $\sqrt{s_{NN}} = 5.02$ TeV in the PACIAE model

We present a study of the single- and multi-strange particle productions in $p$Pb collisions at $\sqrt{s_{NN}} = 5.02$ TeV using the PACIAE 4.0 model. The effects of the color reconnection (CR), rope hadronization (RH) as well as the partonic and hadronic rescatterings (PRS and HRS) on their productions are investigated, respectively. There are two kinds of CR considered: the multiparton interactions-based CR (MPI-CR) and the quantum chromodynamics-based CR (QCD-CR). The four mechanisms studied have little effect on kaon production. However, the QCD-CR scheme incorporating the junction topology gives an enhanced baryon production, but it is still not enough to describe the integrated yields of strange baryons. The combination of QCD-CR and RH scheme together with the flavor ropes (FR) and the string shoving (SS), i.e., QCD-CR+FR+SS, provides a good description of the production of strange baryons. PRS has a weak effect but HRS exerts a promoting effect on the production of multi-strange baryons ($Ξ$ and $Ω$).

hep-ph↗

arXiv2025

StructVRM: Aligning Multimodal Reasoning with Structured and Verifiable Reward Models

Existing Vision-Language Models often struggle with complex, multi-question reasoning tasks where partial correctness is crucial for effective learning. Traditional reward mechanisms, which provide a single binary score for an entire response, are too coarse to guide models through intricate problems with multiple sub-parts. To address this, we introduce StructVRM, a method that aligns multimodal reasoning with Structured and Verifiable Reward Models. At its core is a model-based verifier trained to provide fine-grained, sub-question-level feedback, assessing semantic and mathematical equivalence rather than relying on rigid string matching. This allows for nuanced, partial credit scoring in previously intractable problem formats. Extensive experiments demonstrate the effectiveness of StructVRM. Our trained model, Seed-StructVRM, achieves state-of-the-art performance on six out of twelve public multimodal benchmarks and our newly curated, high-difficulty STEM-Bench. The success of StructVRM validates that training with structured, verifiable rewards is a highly effective approach for advancing the capabilities of multimodal models in complex, real-world reasoning domains.

cs.AI↗

arXiv2025

External Large Foundation Model: How to Efficiently Serve Trillions of Parameters for Online Ads Recommendation

Ads recommendation is a prominent service of online advertising systems and has been actively studied. Recent studies indicate that scaling-up and advanced design of the recommendation model can bring significant performance improvement. However, with a larger model scale, such prior studies have a significantly increasing gap from industry as they often neglect two fundamental challenges in industrial-scale applications. First, training and inference budgets are restricted for the model to be served, exceeding which may incur latency and impair user experience. Second, large-volume data arrive in a streaming mode with data distributions dynamically shifting, as new users/ads join and existing users/ads leave the system. We propose the External Large Foundation Model (ExFM) framework to address the overlooked challenges. Specifically, we develop external distillation and a data augmentation system (DAS) to control the computational cost of training/inference while maintaining high performance. We design the teacher in a way like a foundation model (FM) that can serve multiple students as vertical models (VMs) to amortize its building cost. We propose Auxiliary Head and Student Adapter to mitigate the data distribution gap between FM and VMs caused by the streaming data issue. Comprehensive experiments on internal industrial-scale applications and public datasets demonstrate significant performance gain by ExFM.

cs.IR↗

arXiv2025

The charmonium-like exotic hadron productions in $e^+e^-$ collisions at the BESIII energy with the PACIAE model

Inspired by the BESIII observation of exotic hadron $G$(3900) in $e^+e^-\rightarrow D\bar D$ process [PRL 133(2024)081901], we use the parton and hadron cascade model PACIAE to simulate the productions of charmonium-like exotic hadrons including $X(3872)$, $Z_{c}(3900)^0$ and $G(3900)$ in the $e^+e^-$ annihilations at $\sqrt s$=4.95 GeV. The charmonium-like candidates are recombined by Dynamically Constrained Phase-space Coalescence model using component mesons $D\bar D$ (for $G(3900)$) or $D\bar D^*/\bar DD^*$ (for $X(3872)$, $Z_{c}(3900)^0$ and $G(3900)$) in the PACIAE simulated final hadronic state. We then calculate, for the first time, the charmonium-like candidate's orbital angular momentum quantum number in its rest frame and perform the spectral classification for each of the above candidates. For $G(3900)$, as its $J^{PC}$ is $1^{--}$, it is identified as the $P$-wave $D\bar D$ or $D\bar D^*/\bar DD^*$ state. Meanwhile, for $X(3872)$ and $Z_{c}(3900)^0$, as their $J^{PC}$s are, respectively, $1^{++}$ and $1^{+-}$, they are identified as the $S$-wave $D\bar D^*/\bar DD^*$ candidates. It is observed that the yield of the $P$-wave $G(3900)$ composed of $D\bar D^*/\bar DD^*$ is significantly larger than that composed of $D\bar D$. Moreover, in the $D\bar D^*/\bar DD^*$ channel, the yield of the $P$-wave $G(3900)$ is around three times as large as the yield of the $S$-wave $Z_{c}(3900)^0$, and it is around two orders of magnitude as large as the yield of the $S$-wave $X(3872)$. Finally, significant discrepancies are observed in the transverse momentum spectra and the rapidity distributions among the $X(3872)$, $Z_{c}(3900)^0$ and $G(3900)$ states. These discrepancies are proposed as valuable criteria for identifying the different charmonium-like exotic hadrons from each other.

hep-ph↗

arXiv2025

Spectra and azimuthal harmonic of charmed mesons in Pb+Pb collisions at LHC energies

Using the recombination model (RM) extended to the heavy flavor scenario, we investigate the production of charmed mesons, i.e., $D^0$, $D_s^+$ and $J/ψ$, in Pb+Pb collisions at $\sqrt{s_{NN}}=2.76$ and 5.02 TeV at the CERN Large Hadron Collider (LHC) including the heavy flavor energy loss inside the hot and dense medium. Soft, semihard, and hard partons all play important roles in our model and are uniformly treated for all mesons produced. The resulting transverse momentum spectra and the second azimuthal harmonic $v_2$ for these mesons are presented and compared with the available experimental data. The good agreement provides strong support again that the quark recombination mechanism is a universal scheme of hadronization.

hep-ph↗

arXiv2025

Probing nuclear structure and the equation of state through pre-equilibrium dipole emission in charge-asymmetric reactions

We investigate the pre-equilibrium dipole response in the charge-asymmetric reaction $^{40}$Ca+$^{152}$Sm, of recent experimental interest, at several beam energies within the range $[5, 11]$ AMeV and different collision centralities. By employing Skyrme-like effective interactions for the nuclear mean field, we probe the role of the different ingredients performing theoretical calculations based on the time-dependent Hartree-Fock approach or a semi-classical transport model that also includes two-body correlations. A comparative analysis between these approaches allowed us to disentangle the role of deformation effects in the entrance channel from the ones associated with structure details of genuine quantal nature on the dipole emission. Moreover, we also investigate the impact of the occurrence of residual two-body collisions on the reaction dynamics. This study contributes to the understanding of the microscopic processes that determine the complex dynamics of low-energy heavy-ion collisions along the fusion-fission path, which is relevant to super-heavy element synthesis, unraveling interesting connections with the characteristics of the nuclear effective interaction and the associated equation of state.

nucl-th↗

arXiv2025

Digital Twin Calibration with Model-Based Reinforcement Learning

This paper presents a novel methodological framework, called the Actor-Simulator, that incorporates the calibration of digital twins into model-based reinforcement learning for more effective control of stochastic systems with complex nonlinear dynamics. Traditional model-based control often relies on restrictive structural assumptions (such as linear state transitions) and fails to account for parameter uncertainty in the model. These issues become particularly critical in industries such as biopharmaceutical manufacturing, where process dynamics are complex and not fully known, and only a limited amount of data is available. Our approach jointly calibrates the digital twin and searches for an optimal control policy, thus accounting for and reducing model error. We balance exploration and exploitation by using policy performance as a guide for data collection. This dual-component approach provably converges to the optimal policy, and outperforms existing methods in extensive numerical experiments based on the biopharmaceutical manufacturing domain.

cs.LG↗

arXiv2024

A Brief Introduction to PACIAE 4.0

Parton And-hadron China Institute of Atomic Energy (PACIAE) is a multipurpose Monte Carlo event generator developed to describe a wide range of high-energy collisions, including lepton-lepton, lepton-hadron, lepton-nucleus, hadron-hadron, hadron-nucleus, and nucleus-nucleus collisions. It is built based on the PYTHIA program, and incorporates parton and hadron cascades to address the nuclear medium effects. PACIAE 4.0 is the new generation of PACIAE model surpassing the version 3.0. In PACIAE 4.0, the old fixed-format FORTRAN 77 code has been refactored and rewritten by the free-format modern Fortran and C++ languages. The C++-based PYTHIA 8.3 is interfaced in, while previous versions connected to the Fortran-based PYTHIA 6.4 only. Several improvements are also introduced, which enable PACIAE 4.0 to contain more physics and features to model the high-energy collisions. This is the first attempt to transition PACIAE from Fortran to C++.

hep-ph↗

arXiv2024

Non-extensive (3+1)-dimensional hydrodynamics for relativistic heavy-ion collisions

A non-extensive (3+1)-dimensional hydrodynamic model for multi-particle production processes, NEX-CLVisc, is developed in the framework of CLVisc where the viscous corrections are turned off. It assumes that the non-extensive effects consistently exist in the initial conditions set by the optical Glauber model, the equation of state and the hadron kinetic freeze-out procedure. The model is then applied to simulate the pseudo-rapidity ($η$) distribution, the transverse momentum ($p_{\rm T}$) spectra and the $p_{\rm T}$-differential elliptic flow ($v_2$) of charged particles in Pb-Pb collisions at $\sqrt{s_{\rm NN}}=$ 2.76 TeV and 5.02 TeV, respectively. It is found that the model can reasonably well reproduce the experimental data of the $η$ distribution and the charged-particle spectra in a $p_{\rm T}$ range up to 6-8 GeV/c. When compared with the ideal hydrodynamic model, the $p_{\rm T}$-differential $v_2$ of charged particles is suppressed in the NEX-CLVisc model, which is similar to that observed in the hydrodynamic model with a shear viscous correction. Moreover, due to the lack of the viscous corrections and the event-by-event fluctuation, the model can only describe the $p_{\rm T}$-differential $v_2$ up to 3-4 GeV/c, which is smaller than its applicable range for the particle $p_{\rm T}$ spectra.

nucl-th↗

arXiv2024

X(2370) glueball-like particle productions in $e^+e^-$ collisions at the BESIII energy and in pp collisions at the LHC energy with PACIAE model

Inspired by the BESIII newest observation of X(2370) glueball-like particle, we search its productions in both $e^+e^-$ collisions at $\sqrt{s}=$ 4.95 GeV and proton-proton (pp) collisions at $\sqrt{s}=$ 13 TeV with a parton and hadron cascade model PACIAE. In this model, the final partonic state (FPS) and the final hadronic state (FHS) are consecutively simulated and recorded. The X(2370) glueball- or tetraquark-state is then, respectively, recombined by two gluons or four quarks $ss\bar{s}\bar{s}$ in the FPS using the quantum statistical mechanics inspired dynamically constrained phase-space coalescence (DCPC) model. The X(2370) molecular-state is recombined by the baryon-antibaryon of $Λ$-$\barΛ$ or $Σ$-$\barΣ$, or by three mesons of $π^+π^{-}η'$, $K^+K^-η'$, or $K_S^0K_S^0η'$ in the FHS using DCPC model. In both $e^+e^-$ and pp collisions, significant discrepancies in the yields, the transverse momentum spectra and the rapidity distributions among the X(2370) glueball-, tetraquark-, and molecular-state are observed. These discrepancies are proposed as valuable criteria identifying the X(2370) different states from each other. Our results not only support the BESIII observation of glueball-like particle $\rm X(2370)$ production in $e^+e^-$ collisions, but also serve as a prediction for the $\rm X(2370)$ production in pp collisions. We strongly suggest the experimental measurement of the X(2370) glueball-like particle production in pp collisions at the LHC energies.

hep-ph↗

arXiv2024

Identifying an $\rm X(3872)$ tetraquark state versus a molecular state by formation time, velocity and temperature in relativistic nuclear collisions

The production of exotic hadron $\rm X(3872)$ in $pp$ collisions at $\sqrt{s}=2.76\,\mathrm{TeV}$ is investigated by the parton and hadron cascade model PACIAE in this work. In the simulation the final partonic state (quark matter, QM) and the final hadronic state (hadron matter, HM) are continuously processed and recorded. The $\rm X(3872)$ compact tetraquark state and loose molecular state are, respectively, coalesced and recombined in the QM and HM with the quantum statistical mechanics inspired dynamically constrained phase-space coalescence model. The formation time, velocity and temperature of QM (tetraquark state) and HM (molecular state) are proposed as identifying criteria between the two states. Our results in transverse momentum spectrum and rapidity distribution, etc. show a significant discrepancy between the two states and confirm that they are also valuable criteria identifying the $\rm X(3872)$ compact tetraquark state or molecular state.

hep-ph↗

arXiv2024

Confirming the glueball-like particle $X(2370)$ productions in $e^+e^-$ collisions at BESIII energy with PACIAE model

The parton and hadron cascade model {\footnotesize PACIAE} is employed to confirm the BESIII newest observation of glueball-like particle $\rm X(2370)$ production in $e^+e^-$ collisions at $\sqrt{s}=4.95\,\mathrm{GeV}$. We coalesce the $\rm X(2370)$ glueball state with two gluons in the simulated partonic final state by the Dynamically Constrained Phase-space Coalescence ({\footnotesize DCPC}) model. Alternative configuration of $\rm X(2370)$ molecular state is recombined in the simulated hadronic final state with $π^{+},π^{-},K^{+}, K^{-},K_{S}^{0},K_{S}^{0}$ and $η'$ by {\footnotesize DCPC} model. The resulted particle transverse momentum spectrum and rapidity distribution, etc. show a significant discrepancy between the two states. They are not only serving as criteria to distinguish the $\rm X(2370)$ glueball state or molecular state, but also confirming the BESIII observation of glueball-like particle $\rm X(2370)$ productions in $e^+e^-$ collisions.

hep-ph↗

arXiv2024

Digital Twin Calibration for Biological System-of-Systems: Cell Culture Manufacturing Process

Biomanufacturing innovation relies on an efficient Design of Experiments (DoEs) to optimize processes and product quality. Traditional DoE methods, ignoring the underlying bioprocessing mechanisms, often suffer from a lack of interpretability and sample efficiency. This limitation motivates us to create a new optimal learning approach for digital twin model calibration. In this study, we consider the cell culture process multi-scale mechanistic model, also known as Biological System-of-Systems (Bio-SoS). This model with a modular design, composed of sub-models, allows us to integrate data across various production processes. To calibrate the Bio-SoS digital twin, we evaluate the mean squared error of model prediction and develop a computational approach to quantify the impact of parameter estimation error of individual sub-models on the prediction accuracy of digital twin, which can guide sample-efficient and interpretable DoEs.

q-bio.QM↗

arXiv2024

Revisiting the 3α reaction rates in helium burning stars

Helium burning is one of the most fundamental steps of stellar nucleosynthesis, as it describes the formation of life-determining element of carbon, while it plays a key role in the evolution of Red Giant, accreting White Dwarfs and Neutron Stars. In this work we develop a generalized statistical theory for the 3α reaction, which is based on the use of the Imaginary Time Method, along with the semi-classical Hybrid α-Clustering (HαC) and Neck Model (NM) frameworks. The results compared to the methodology and data of the NACRE collaboration, following in several orders of magnitude discrepancies, especially at low temperatures. This may be crucial for the early dynamics of helium burning stars.

nucl-th↗