arXiv subjects

Yu Jia

Publications and source records attributed to Yu Jia.

At least 19 recordsLinked to original sources

arXiv2026

Recovering Readout-Limited Fisher Information in Superconducting-Qubit Magnetometry with Squeezed Microwaves

The performance of superconducting-qubit magnetometers depends not only on magnetic-field encoding during Ramsey interrogation, but also on how efficiently the encoded information is recovered during readout. Here we quantify how squeezed-microwave-assisted dispersive readout can recover magnetic-field information lost during qubit-state assignment. We develop an effective detected-mode framework linking projected quadrature noise, state-assignment error, and the classical Fisher information accessible from binary readout outcomes. A finite mismatch between the squeezed quadrature and the discrimination axis produces an optimal squeezing strength through the competition between squeezed and anti-squeezed fluctuations. For representative parameters, squeezed readout reduces the readout-limited magnetic-field sensitivity bound by $27.3\%$. This improvement arises from recovering information lost in the readout stage rather than from increasing the information encoded during Ramsey interrogation. These results may provide a practical route for mitigating measurement-stage information loss in superconducting quantum sensing.

quant-ph↗

arXiv2026

Inverse Density Problem for Linear Elasticity: Uniqueness from Local Measurements on a Partially Accessible Boundary

We consider the inverse boundary value problem in an elasticity system. It is proved that the density function $ρ$ and its derivatives at the boundary can be uniquely determined from the local Cauchy data. Furthermore, if the density function is analytic, we can uniquely determine the internal buried objects, as well as the unknown boundary and the boundary conditions imposed on it. Our methods mainly based on a precise characterization for the principal part of the difference between a special first-order singular solution and the fundamental solution in the $H^m$ norm, and the blow-up property for the boundary Sobolev norms of the volume potential corresponding to the fundamental solution.

math.AP↗

arXiv2026

Simultaneous Reconstruction of Multiple Unknowns in Stokes-Darcy System from Partial Boundary Data

This paper studies an inverse boundary value problem for a coupled Stokes-Darcy system modeling fluid-porous medium interaction, with an unknown solid object embedded in the free-flow region. We simultaneously recover the viscosity coefficient $μ$, the interface $Γ$, and the internal object $D$ from localized boundary Cauchy data. A novel method based on the construction of an interior transmission problem is introduced, which can amplify the singularity of solutions. We establish a global uniqueness theorem, showing that all three unknowns are uniquely determined by the boundary measurements.

math.AP↗

arXiv2026

Next-to-next-to-leading order QCD corrections to pion (kaon)-induced exclusive Drell-Yan process

The high-energy pion and kaon beams proposed for future experiments at J-PARC offer a unique opportunity to investigate exclusive Drell-Yan processes induced by pions or kaons, which correspond to inverse deeply virtual meson production with $M=π,K$. To facilitate precise comparisons between theoretical predictions and forthcoming experimental data, we calculate the next-to-next-to-leading order (NNLO) QCD corrections to the processes $π^- p\to γ^*(\to l^+l^-) + n$ and $K^- p\to γ^*(\to l^+l^-) + Λ$. Our calculations are performed within the generalized parton distribution (GPD) factorization framework, accurate to leading twist in the generalized Bjorken limit ($Q^2\gg |t|,\,Λ_{\rm QCD}^2$). We find that the NNLO QCD corrections are substantial and positive; therefore, their inclusion is imperative for reliable theoretical predictions in confrontation with future experiments.

hep-ph↗

arXiv2026

Next-to-next-to-leading-order QCD corrections to ${}^3S_1^{(8)}$ gluon fragmentation function for quarkonium

We present the first computation of the next-to-next-to-leading-order (NNLO) QCD corrections to the ${}^3S_1^{(8)}$ gluon fragmentation function for quarkonium within the nonrelativistic QCD (NRQCD) factorization framework, accurate to the lowest order in the velocity expansion. The calculation is performed with high numerical precision and encompasses both polarized and unpolarized cases. We find that the NNLO corrections are positive and substantial across most of the $z$ region. Furthermore, the logarithmic singularities near the endpoint $z\to 1$ are fully reconstructed, providing essential inputs for future threshold resummation beyond leading-logarithmic accuracy. Combined with threshold-resummed formulas in the large-$z$ region, our results yield phenomenologically viable inputs for the $^3S_1^{(8)}$ gluon fragmentation function. This enables a more reliable description of large-$p_T$ $J/ψ$ ($ψ'$) and $χ_{cJ}$ production and polarization at hadron colliders, representing a crucial step toward a definitive test of the color-octet mechanism.

hep-ph↗

arXiv2026

Deeply virtual pion production through two-loop order

Deeply virtual meson production (DVMP) is among the most prominent channels to extract the nucleon's generalized parton distributions (GPDs) at $ep$ scattering facilities such as {\tt JLab} and the upcoming {\tt EIC/EicC} experiments, which plays a vital role in unravelling the three-dimensional internal structure of nucleon. In this work we calculate for the first time the next-to-next-to-leading order (NNLO) QCD radiative corrections to the DV$π$P processes $γ_L^* p\to π^+ n$ and $γ_L^* p\to π^0 p$ in the generalized Bjorken limit $Q^2\gg \vert t\vert, Λ_{\text{QCD}}^2$, accurate at the leading twist within collinear factorization framework. The impact of the two-loop QCD corrections appears to be positive and substantial, including which considerably improves the agreement between the perturbative QCD prediction and the available {\tt JLab} data. In addition to the differential longitudinal DV$π$P cross section, we also study the impact of the two-loop QCD corrections on the transverse single-spin asymmetries (TSSA) in some benchmark kinematics at {\tt JLab}, {\tt EIC} and {\tt EicC}.

hep-ph↗

arXiv2026

Institutional Trust and the Domestic AI Advantage: Evidence from DeepSeek and ChatGPT Users in China

Public trust in generative artificial intelligence exhibits increasingly divergent patterns across national contexts, yet prevailing research largely overlooks the macro-structural forces underlying this divergence. This study argues that trust in AI is not merely a technical response to performance but a product of institutional refraction. We propose an ``Institutional Prism'' framework to demonstrate how institutional trust shapes user trust in domestic (DeepSeek) and global (ChatGPT) large language models. Drawing on Cognitive-Affective Trust Theory, we distinguish between cognitive and affective dimensions of trust and analyze survey data from 405 Chinese users. The findings show that higher institutional trust is positively associated with stronger affective trust in domestic AI models and shifts cognitive evaluations in a more favorable direction. While under lower institutional trust, this domestic advantage weakens. These findings reveal that institutional trust has emerged as a core dimension of AI trust formation. By linking micro-level psychological judgments with macro-level governance, this research contributes a new perspective to human-machine communication.

cs.CY↗

arXiv2026

Solving bound-state equations in $\text{QCD}_2$ with bosonic and fermionic quarks

We investigate the bound-state equations (BSEs) in two-dimensional QCD in the $N_c\to \infty$ limit, viewed from both the infinite momentum frame (IMF) and the finite momentum frame (FMF). The BSE of a meson in the original 't Hooft model, viz., spinor $\text{QCD}_2$ containing only fermionc quarks, has been extensively studied in literature. In this work, we focus on the BSEs pertaining to two types of "exotic" hadrons, a "tetraquark" which is composed of a bosonic quark and bosonic antiquark, and a "baryon" which is composed of a bosonic antiquark and a fermionic quark. Utilizing the Hamiltonian approach, we derive the corresponding BSEs for both types of "exotic" hadrons, from the perspectives of the light-front and equal-time quantization, and confirm the known results. The recently available BSEs for "tetraquark" in FMF has also been recovered with the aid of the diagrammatic approach. For the first time we also present the BSEs of a "baryon" in FMF in the extended 't Hooft model. By solving various BSEs numerically, we obtain the mass spectra pertaining to "tetraquark" and "baryon" and the corresponding bound-state wave functions of the lowest-lying states. It is numerically demonstrated that, when a "tetraquark" or "baryon" is continuously boosted, the forward-moving component of the bound-state wave function approaches the corresponding light-cone wave function, while the backward-moving component fades away.

hep-ph↗

arXiv2025

Azimuthal asymmetry in $J/ψ+γ$ and $J/ψ+J/ψ$ production in ultraperipheral heavy-ion collisions at LHC

Two-photon collision in ultraperipheral heavy-ion collisions (UPCs) provides a unique and powerful platform for probing QCD with linearly polarized quasi-real photons. While photon polarization effects have been recognized in dilepton and even in light hadrons production, their consequences for heavy quarkonium production remain unexplored. In this work we investigate for the first time the $γγ\to J/ψ+γ(J/ψ)$ channels in Pb-Pb UPCs at the Large Hadron Collider (LHC), by integrating the non-relativistic QCD (NRQCD) factorization approach with the transverse-momentum-dependent (TMD) photon distributions. Based on the helicity amplitudes at lowest order in strong coupling and velocity expansion, we predict sizable $\cos(2ϕ)$ and $\cos(4ϕ)$ azimuthal asymmetries arising from the interference of linearly polarized photon states. These azimuthal-dependent observables, defined as the ratios of weighted to unweighted cross sections, are expected to be stable against including the higher-order radiative corrections and varying nonperturbative NRQCD matrix elements, thus offering a fresh test of quarkonium production mechanism and the photon TMD structure in the ultrarelativistic limit.

hep-ph↗

arXiv2025

Recovering discontinuous viscosity coefficients for inverse Stokes problems by boundary measurements

In this paper, we investigate the inverse Stokes problem of determining a discontinuous viscosity coefficient $μ$ in a bounded domain $Ω\subset\mathbb{R}^3$. By analyzing the singularity of the Dirichlet Green's functions in $H^1$-norm and constructing a specifically coupled Stokes-Brinkman system in a localized domain, we prove a global uniqueness theorem that the viscosity coefficient $μ$ can be uniquely determined from boundary measurements.

math.AP↗

arXiv2025

Mixed Electroweak-QCD Corrections to $H\to γγ$

We present for the first time the complete three-loop mixed electroweak-QCD ($\mathcal{O}(αα_s)$) corrections for the decay channel $H \to γγ$, by implementing three different on-shell $α$ schemes in computing the electroweak correction. Our studies indicate that the $\mathcal{O}(α_s)$ correction amounts to approximately $1.7\%$ of the leading-order prediction for the diphoton width, while the $\mathcal{O}(α)$ correction varies from $-4.8\%$ to $1.4\%$ depending on the specific $α$ scheme. The three-loop mixed electroweak-QCD correction may reach $0.6\%$, $0.5\%$, and $0.2\%$ of the LO diphoton width in $α(0)$, $α(M_Z)$, and $G_μ$ schemes, respectively, which is much more significant than the less-than-$0.1\%$ contribution from the three-loop QCD correction. It is also worth noting that the inclusion of the ${\cal O}(αα_s)$ correction significantly reduces the scheme dependence of the partial width from $0.6$ keV at leading order down to $0.03$ keV. The state-of-the-art Standard Model predictions are $Γ[H \to γγ] = 9.389÷9.420$ keV, providing a valuable theoretical benchmark for future Higgs factory collider program.

hep-ph↗

arXiv2025

Optimized QCD two-loop correction to exclusive double $J/ψ$ production at B factories

We report the calculation of the process $e^+ e^- \to J/ψJ/ψ$ up to next-to-next-to-leading order (NNLO) at a center-of-mass (CM) energy of $\sqrt{s}=10.58$ GeV. We employ an improved NRQCD factorization approach, decomposing the amplitude into photon-fragmentation and non-fragmentation components. The fragmentation contribution is determined using the measured $J/ψ$ decay constant, while the interference and non-fragmentation parts are computed at NNLO in $α_s$ and lowest order in velocity. In this optimized scheme, both ${\cal O}(α_s)$ and ${\cal O}(α^2_s)$ corrections in the interference part are positive and exhibit good convergence. The non-fragmentation part is numerically insignificant. Our results indicate that with the projected 50 ${\rm ab}^{-1}$ dataset at \texttt{Belle 2}, the prospects for observing exclusive double $J/ψ$ production are very promising.

hep-ph↗

arXiv2025

Optimally Tensile Strained La3Ni2O7 Films as Candidate High-Temperature Superconductors on Designer Ba1-xSrxO (001) and SrO-SrTiO3 Substrates

Recent experiments have observed superconductivity up to 48 K in La3Ni2O7-derived films under compressive strain imposed by the SrLaAlO4 substrate, while such films on the SrTiO3 substrate with tensile strain have failed to reach the superconducting state. Here we propose to broadly expand the choices of materials platforms to achieve high-Tc superconducting La3Ni2O7 films by proposing designer substrates of Ba1-xSrxO (x = 0 - 1) that allow to continuously tune the strain in the films from being tensile to compressive. Our systematic study of the structural and electronic reconstructions of the strained La3Ni2O7 bilayer film leads to the central finding that at the optimal tensile strain of ~2% (x ~0.25), the spectral weight of the Ni dz2 orbital is peaked right at the Fermi level, and its hybridization with the Ni dx2-y2 orbital is substantially enhanced. Consequently, the expected Tc should be unprecedentedly high, at least substantially higher than those achieved in the compressive regime. Furthermore, our detailed thickness-dependent energetic analyses show that such films can be stably grown for thicknesses equal to or beyond the bilayer regime, and predict that the SrO-terminated SrTiO3 should also be able to stabilize the films with optimal tensile strain and higher Tc's.

cond-mat.supr-con↗

arXiv2025

Contrasting magnetic anisotropy in CrCl3 and CrBr3: A first-principles study

We present a first-principles study of the contrasting easy magnetization axes(EMAs) in the layered chromium trihalides CrCl3 and CrBr3, which exhibit in-plane and out-of-plane EMAs, respectively. Using density-functional theory calculations, we show that the EMA is determined by the interplay between spin-orbit coupling-induced magnetocrystalline anisotropy energy (SOC-MAE) and shape magnetic anisotropy energy(shape-MAE) arising from dipole-dipole interactions. While the Cr d orbitals contribute similarly to the SOC-MAE in both compounds, the key difference stems from the halogen p orbitals. In CrCl3, the localized Cl 3p orbitals favor spin-flip SOC interactions, particularly between the (px, py) and (py, pz) channels. These channels contribute with opposite signs-negative and positive, respectively-leading to partial cancellation and a small net SOC-MAE. As a result, the shape-MAE exceeds the SOC-MAE in magnitude, favoring an in-plane EMA. In contrast, CrBr3 features more delocalized Br 4p orbitals, enhanced p-d hybridization, and stronger SOC. This leads to stronger spin-conserving SOC interactions, with dominant contributions from both the (px, py) and (py, pz) channels. In this case, the positive contribution from the (px, py) channel outweighs the smaller negative contribution from the (py, pz) channel, resulting in a sizable net SOC-MAE. The SOC-MAE thus surpasses the shape-MAE and stabilizes an out-of-plane EMA. These findings demonstrate that the contrasting magnetic anisotropies in CrCl3 and CrBr3 originate from differences in the spatial distribution, SOC strength, and hybridization of the halogen p orbitals, highlighting the critical role of orbital anisotropy and spin selection rules in governing magnetic behavior in layered semiconductors.

cond-mat.mtrl-sci↗

arXiv2025

Next-to-leading-order QCD corrections to nucleon Dirac form factors

The leading-order perturbative QCD (pQCD) predictions to nucleon electromagnetic form factors were first made in late 70s. In this Letter for the first time we accomplish the calculation of the next-to-leading-order (NLO) QCD corrections to nucleon's Dirac form factors at large momentum transfer, to the leading-twist accuracy in collinear factorization approach, specifically within the Krankl and Manashov renormalization scheme. The effect of NLO perturbative corrections turns out to be positive and substantial. Taking the nucleon leading-twist light-cone-distribution amplitudes (LCDAs) determined from the recent lattice simulations as input, we find that the state-of-the-art pQCD predictions significantly underestimate the available nucleon Dirac form factors in both space-like and time-like domains. This nuisance indicates that some additional soft nonfactorizable contribution might be called for to account for the measured nucleon electromagnetic form factor data up to $Q^2\approx 30\;{\rm GeV^2}$.

hep-ph↗

arXiv2025

Novel azimuthal observables from two-photon collision at $e^+e^-$ colliders

In this work we advocate a set of novel azimuthal-angle-related observables associated with exclusive hadron production from two-photon fusion at $e^+ e^-$ colliders, taking the $γγ\to ππ$ as a benchmark process. As a direct consequence of the linearly polarized quasi-real photons emitted off the electron and positron beams, the $\cos 2ϕ$ azimuthal asymmetry in dipion production is predicted within the transverse-momentum-dependent (TMD) factorization framework. In numerical analysis, we take the helicity amplitudes of $γγ\to ππ$ determined from the partial wave solutions in dispersion relation as input, and find that the predicted $\cos2ϕ$ azimuthal modulation may reach 40\% for the typical kinematical setup of {\tt Belle 2} and {\tt BESIII} experiments. Future accurate measurement of this azimuthal asymmetry may facilitate the direct extraction of the relative phase between two helicity amplitudes with photon helicity configurations $++$ and $+-$. This knowledge provides a valuable input for the dispersive determination of the hadronic light-by-light (Hlbl) contributions.

hep-ph↗

arXiv2025

Deciphering the coalescence behavior of Coulomb-Schrödinger atomic wave functions from an operator product expansion

We revisit the coalescence behavior of the atomic Schrödinger wave functions from the angle of an operator product expansion (OPE) within the nonrelativistic Coulomb-Schrödinger effective field theory. We take the electron-nucleus coalescence as an explicit example to demonstrate our formalism, where the celebrated Kato's cusp condition can be easily reproduced. An exact OPE relation is rigorously proved to all orders in perturbation theory. Our approach can be readily extended to ascertain the multi-particle coalescence behaviors of atomic wave functions, as well as to take relativistic effects into account.

hep-ph↗

arXiv2025

Azimuthal modulation in light-by-light scattering from ultraperipheral collisions at LHC

Elastic light-by-light(LbL) scattering, one of the most fascinating processes in the Standard Model(SM), has recently been observed in the ultraperipheral collisions(UPCs) of relativistic heavy ions in the Atlas and CMS experiments at the Large Hadron Collider LHC. Recognizing that the incident quasi-real photons in LbL scattering are strongly linearly polarized, we re-investigate the LbL scattering in UPCs by incorporating the joint dependence of the impact parameter and transverse momenta of the incident photons. We show that the linear polarization of incident photons generates a sizable $\cos2ϕ$-type azimuthal modulation, which awaits the test in future LHC and EIC experiments.

hep-ph↗