Fri·Mar 14, 2025Friday·March 14, 2025

1. 01*

   Tools for Unbinned Unfolding

   Ryan Milton🇺🇸 · Vinicius Mikuni🇺🇸 · Trevin Lee🇺🇸 · Miguel Arratia🇺🇸 · Tanvi Wamorkar🇺🇸 · Benjamin Nachman🇺🇸

   Machine learning has enabled differential cross section measurements that are not discretized. Going beyond the traditional histogram-based paradigm, these unbinned unfolding methods are rapidly being integrated into experimental workflows. In order to enable widespread adaptation and standardization, we develop methods, benchmarks, and software for unbinned unfolding. For methodology, we demonstrate the utility of boosted decision trees for unfolding with a relatively small number of high-level features. This complements state-of-the-art deep learning models capable of unfolding the full phase space. To benchmark unbinned unfolding methods, we develop an extension of existing dataset to include acceptance effects, a necessary challenge for real measurements. Additionally, we directly compare binned and unbinned methods using discretized inputs for the latter in order to control for the binning itself. Lastly, we have assembled two software packages for the OmniFold unbinned unfolding method that should serve as the starting point for any future analyses using this technique. One package is based on the widely-used RooUnfold framework and the other is a standalone package available through the Python Package Index (PyPI).

   hep-phhep-exphysics.data-anJINST(2025)·7 citations
2. 02*

   Leptogenesis During an Era of Early SU(2) Confinement

   India Bhalla-Ladd🇺🇸 · Izzy Ginnett🇺🇸 · Tim M.P. Tait🇺🇸

   We explore leptogenesis during a cosmological epoch during which the electroweak $SU(2{)}_L$ force is confined. During weak confinement, there is only one conserved non-anomalous global charge, $r$, which is a linear combination of lepton-number, baryon-number, and hypercharge. The inclusion of heavy Majorana neutrinos leads to an $r$-charge and $CP$-violating interaction, allowing for the generation of an $r$-charge asymmetry, which translates into a baryon asymmetry post $SU(2{)}_L$ deconfinement. Determining the resulting baryon asymmetry as a function of the model parameters, we find that the predicted baryon-asymmetry can match observations for a wide swath of parameter space. While leptogenesis under the assumption of a standard cosmology relies on the complex phase of the neutrino Yukawa couplings, the asymmetry generated in this novel background cosmology primarily depends on a strong phase from $SU(2{)}_L$ confinement and favors negligible $CP$-violation in the right-handed neutrino decays.

   hep-phhep-thPRD(2025)·4 citations
3. 03*

   Precise $K^{\ast }(892)\to K\pi$ branching fractions

   Vladimir V. Gligorov🇫🇷 · Dean J. Robinson🇺🇸

   Although discovered more than sixty years ago, direct measurement of the $K^{\ast }(892)\to K\pi$ branching fractions is a formidable challenge that has not been attempted. Typically they are assumed to obey the isospin limit in hundreds of particle data measurements. We show that an abundance of recent amplitude analyses and other data, however, enables recovery of the ratios $\mathcal{B}(K^{\ast +}\to K^{+}{\pi }^0)/\mathcal{B}(K^{\ast +}\to K_S^0{\pi }^{+})$ and $4\mathcal{B}(K^{\ast 0}\to K_S^0{\pi }^0)/\mathcal{B}(K^{\ast 0}\to K^{+}{\pi }^{-})$ at $\sim 5\%$ precision.

   hep-phhep-exPRD(2026)·0 citations
4. 04*

   Probing Leptogenesis at LISA: A Fisher analysis

   Rome Samanta🇮🇹

   In JCAP 11 (2024) 051, we discussed how different regimes (flavoured) of leptogenesis can be probed through a ``tomographic'' approach using primordial gravitational waves. By examining the theory's parameter space, we identified regions where right-handed neutrino mass-dependent non-standard cosmological expansion leaves characteristic imprints on propagating gravitational waves. Our analysis focused on inflationary blue-tilted gravitational waves, modeled by a power-law tensor power spectrum with a constant spectral index. The resulting double-peak spectrum -- where peak and dip frequencies are sensitive to leptogenesis parameters -- provided marked signatures of different leptogenesis regimes. In this follow-up article, we conduct a statistical analysis of two-flavour leptogenesis signals, particularly those producing a peak (more generally, a broken power-law signal) within the LISA frequency band. Using a Fisher matrix analysis, we delineate the regions of parameter space that LISA can probe with minimal uncertainty, accounting for galactic and extragalactic foregrounds along with LISA's instrumental noise.

   hep-phastro-ph.COgr-qcJCAP(2025)·9 citations
5. 05*

   Interplay of non-standard interactions and Earth's composition in atmospheric neutrino oscillations

   Juan Carlos D'Olivo🇲🇽 · José Arnulfo Herrera Lara🇲🇽 · Ismael Romero🇦🇷 · Matias Reynoso🇦🇷 · Oscar A. Sampayo🇦🇷

   Many geophysical and geochemical phenomena in the Earth's interior are related to physical and chemical processes in the outer core and the core-mantle boundary, which are directly linked to the isotopic composition. Determining the composition using standard geophysical methods has been challenging. Atmospheric neutrino oscillations, influenced by their weak interactions with terrestrial matter, offer a new way to gather valuable information about the Earth's internal structure and, in particular, to constrain the composition of the core. If neutrinos had as yet unknown non-standard interactions (NSI), this could affect their propagation in matter and consequently impact studies of Earth's composition using neutrino oscillation tomography. This study focuses on scalar-mediated NSI and their potential impact on atmospheric neutrino oscillations, which could obscure information about the hydrogen content in the outer core. In turn, compositional uncertainties could affect the characterization of NSI parameters. The analysis is based on a Monte-Carlo simulation of the energy distribution and azimuthal angles of neutrino-generated $\mu$ events. Using a model of the Earth consisting of 55 concentric shells with constant densities determined from the PREM, we evaluate the effect on the number of events due to changes in the outer core composition (Z/A)${}_{oc}$ and the NSI strength parameter $ϵ$. To examine the detection capability to observe such variations, we consider regions in the plane of (Z/A)${}_{oc}$ and $ϵ$ where the statistical significance of the discrepancies between the modified Earth model and the reference model is less than $1\sigma$.

   hep-phphysics.geo-phEPJC(2025)·1 citation
6. 06*

   Spin density matrix for neutral $\rho$ mesons in a pion gas in linear response theory

   Yi-Liang Yin🇨🇳 · Wen-Bo Dong🇨🇳 · Cong Yi🇨🇳 · Qun Wang🇨🇳

   We calculate the spin density matrix for neutral $\rho$ mesons from the spectral function and thermal shear tensor by Kubo formula in the linear response theory, which contributes to the $\gamma$ correlator for the CME search. We derive the spectral function of neutral $\rho$ mesons with $\rho \pi \pi$ and $\rho \rho \pi \pi$ interactions using the Dyson-Schwinger equation. The thermal shear tensor contribution is obtained from the Kubo formula in the linear response theory. We numerically calculate ${\rho }_{00}-1/3$ and $\mathrm{Re}{\rho }_{-1,1}$ using the simulation results for the thermal shear tensor by the hydrodynamical model, which are of the order $10^{-3}\sim 10^{-2}$.

   hep-phSCPMA(2026)·4 citations
7. 07*

   Nucleon resonance structure to 2 GeV and the nature of the Roper

   Shiryo Owa🇦🇺 · Derek B. Leinweber🇦🇺 · Anthony W. Thomas🇦🇺

   The study of the spectrum of excited states of the nucleon is vital to our understanding of how QCD is realized in the baryon spectrum. Using a simultaneous analysis of the pion nucleon scattering data up to 2 GeV as well as the results of lattice QCD calculations, we obtain new insight into the nature of the Roper resonance as well as the excited states around 1.9 GeV.

   hep-phhep-latnucl-thPRD(2025)·12 citations
8. 08*

   More about quark Yukawa textures from selection rules without group actions

   Tatsuo Kobayashi🇯🇵 · Yume Nishioka🇯🇵 · Hajime Otsuka🇯🇵 · Morimitsu Tanimoto🇯🇵

   We study the coupling selection rules associated with non-group symmetries, i.e., ${\mathbb{Z}}_2$ gauging of ${\mathbb{Z}}_M$ symmetries. We clarify which Yukawa textures can be derived by our selection rules for $M=3,4$, and 5, and obtain various textures including the the nearest neighbor interaction type and its extension. Some of them cannot be realized by a conventional group-like symmetry. They lead to interesting phenomenology such as a solution to the strong CP problem without axion.

   hep-phhep-thJHEP(2025)·44 citations
9. 09*

   Stability of quark matter affected by the surface tension in a strong magnetic field

   Yu-Ying He🇨🇳 · Xin-Jian Wen🇨🇳

   The surface tension of quark matter in a strong magnetic field is investigated using a geometric approach. The interface between the hadronic phase and quark phase is determined by the Maxwell construction of the first-order transition. When surface tension is included, the free energy per baryon is no longer a monotonic function of the chemical potential. Specifically, for smaller droplets, a larger chemical potential is required to achieve a stable phase. Moreover, we find that the surface tension does not increase monotonically with the magnetic field. Finally, it is shown that stable quark matter, both with and without surface tension, can exist at a specific magnetic field strength, which would provide favorable conditions for the experimental production of quark matter.

   hep-phEPJA(2025)·0 citations
10. 10*

    $J/\psi$-meson photoproduction off the nucleon in a dynamical model

    Sang-Ho Kim🇰🇷

    The photoproduction of $J/\psi$ meson off the nucleon is investigated within a dynamical model approach based on a Hamiltonian which describes the reaction mechanisms of the Pomeron exchange, meson exchange, and direct $J/\psi$ radiation terms.To shed light on the low-energy mechanism, we scrutinize the role of light-meson [${\pi }^0(135)$, $\eta (548)$, ${\eta }^{\prime }(958)$, $f_1(1285)$] and charmonium-meson [${\eta }_c(1S)$, ${\chi }_{c0}(1P)$, ${\chi }_{c1}(1P)$, ${\eta }_c(2S)$, ${\chi }_{c1}(3872)$] exchanges in the $t$-channel diagram. The values of the coupling constants are mostly determined by the radiative decays of the $J/\psi$ meson or the relevant charmonium mesons. The final $J/\psi$-$N$ interaction is required by the unitarity condition and is described by the gluon-exchange and direct $J/\psi N$ coupling terms. The parameters of the Hamiltonian are determined by the latest GlueX and $J/\psi$-007 experiments at the Jefferson Laboratory (JLab). We find that $\eta (548)$ and ${\eta }^{\prime }(958)$ light mesons give the most significant contribution to $\gamma p\to J/\psi p$ among the meson-exchange terms.Meanwhile, the effect of charmonium mesons turns out to be small compared to that of light mesons.It turns out that the contribution of the FSI term is about 1 - 2 orders of magnitude smaller than that of the Born term and is significant near the threshold when the Yukawa form is used as for the charmonium-nucleon potential. The resulting total and $t$-dependent differential cross sections provide good agreement with the JLab data. The angle-dependent data with high precision near the very threshold ($E_{\gamma }⩽8.9$ GeV) are strongly desired to pin down the role of the FSI term more properly.

    hep-phPLB(2025)·6 citations
11. 11*

    Investigation of box diagrams for the peak of $Z_{cs}(3985)$ in $e^{+}{e}^{-}\to D_s^{-}{D}^{\ast 0}{K}^{+}$ and $D_s^{\ast -}{D}^0{K}^{+}$

    Yuan-Xin Zheng🇨🇳 · Gang Li🇨🇳 · Shi-Dong Liu🇨🇳 · Jia-Jun Wu🇨🇳

    The BESIII collaboration recently observed a charged hidden-charm structure with strangeness in the recoil mass spectrum of $K^{+}$ in the processes $e^{+}{e}^{-}\to D_s^{-}{D}^{\ast 0}{K}^{+}$ or $D_s^{\ast -}{D}^0{K}^{+}$, named as $Z_{cs}(3985{)}^{-}$. Within the energy region around the peak of $Z_{cs}(3985)$, various box diagrams are present. A systematic study of these box diagrams reveals the existence of a box singularity. Dalitz plots and invariant mass distributions of two charmed mesons from the box diagram for the processes $e^{+}{e}^{-}\to D_s^{-}{D}^{\ast 0}{K}^{+}$ and $D_s^{\ast -}{D}^0{K}^{+}$ are presented at five energy points $\sqrt{s}=4.628,4.641,4.661,4.681$, and $4.698$ GeV. It is found that these box diagrams can generate peaks similar to those observed in experiments, suggesting that the peak of $Z_{cs}(3985)$ may be attributed to the box singularity contribution. Additionally, slight differences in the invariant mass spectra of $D_s^{-}{D}^{\ast 0}$ and $D_s^{\ast -}{D}^0{K}^{+}$ are identified based on the box diagrams, needing further experimental validation.

    hep-phEPJC(2025)·0 citations
12. 12*

    Basis light-front quantization for the ${\Lambda }_b$ and ${\Sigma }_b$ baryons

    Lingdi Meng🇨🇳 · Tian-Cai Peng🇨🇳 · Zhi Hu🇯🇵 · Siqi Xu🇨🇳 · Jiangshan Lan🇨🇳 · Chandan Mondal🇨🇳 · Guo-Li Wang🇨🇳 · Xingbo Zhao🇨🇳 · James P. Vary🇺🇸

    Within the basis light-front quantization framework, we compute the masses and light-front wave functions of the ${\Lambda }_b$ baryon and its isospin triplet counterparts ${\Sigma }_b^{+}$, ${\Sigma }_b^0$, and ${\Sigma }_b^{-}$ using a light-front effective Hamiltonian in the leading Fock sector. These wave functions are obtained as eigenstates of the effective Hamiltonian, which incorporates the one-gluon exchange interaction with fixed coupling and a three-dimensional confinement potential. With the quark masses and the couplings as adjustable parameters, the computed masses are set within the experimental range. The resulting predictions for their electromagnetic properties align well with other theoretical calculations. Additionally, the parton distribution functions (PDFs) of these baryons are obtained for the first time, with gluon and sea quark distributions dynamically generated through QCD evolution of the valence quark PDFs.

    hep-phhep-thPRD(2025)·3 citations
13. 13*

    Decay rates of ${\Lambda }_b^0\to {\Lambda }_c^{+}{\ell }^{-}{\bar{\nu }}_{\ell }$ using helicity analysis and phase-moment parametrization

    Sara Rahmani🇨🇳

    Based on the helicity method, formulae for the semileptonic transition of ${\Lambda }_b^0\to {\Lambda }_c^{+}{\ell }^{-}{\bar{\nu }}_{\ell }$ including lepton mass effects are derived. In order to calculate the form factors of the ${\Lambda }_b$ baryon transition matrix element, we employ the phase-moment parameterization and perform fits to the Lattice QCD data. With the help of the obtained form factors, six helicity amplitudes and the differential decay widths are evaluated. Through appropriate angular integrations, we express the helicity flip, helicity nonflip integrated decay rates, and the lepton-side forward-backward asymmetry. We present a numerical analysis of these physical observables. We obtain the mentioned physical quantities by performing fits to the Lattice QCD data using the well-known Boyd-Grinstein-Lebed parametrization. Comparisons with other experimental and theoretical data are also discussed.

    hep-phJ.Phys.G(2025)·0 citations
14. 14*

    $gg\to HH$ amplitude induced by bottom quarks at two-loop level: planar master integrals

    Zhenghong Hu🇨🇳 · Tao Liu🇨🇳 · Jin Min Yang🇨🇳

    We consider the two-loop amplitude of $gg\to HH$ mediated by bottom quarks, which provides a correction of percent level at leading order in the low invariant mass region. In order to compute the corresponding master integrals, we perform an expansion for the bottom quark mass, using the method of differential equations and fixing the boundary constants by a numerical approach. The results of 177 planar master integrals which are expressed in terms of multiple polylogarithms are provided.

    hep-phJHEP(2025)·9 citations
15. 15*

    Light Pentaquark Searches with Hadron Beams

    Jung Keun Ahn🇰🇷

    This review deals with measurements and future experiments of light pentaquark searches using hadron beams.

    hep-phhep-exnucl-exActa Phys.Polon.B(2025)·0 citations
16. 16*

    Exploring the multiplicity dependence of the flavor hierarchy for hadron productions in high energy pp collisions

    Aogui Zhang · Xinye Peng · Liang Zheng

    In this work, we perform a systematic study on the multiplicity dependence of hadron productions at mid-rapidity ($|y|<0.5$), ranging from the light to the charm sector in pp collisions at $\sqrt{s}=13$ TeV. This study utilizes a multi-phase transport model (AMPT) coupled with PYTHIA8 initial conditions. We have investigated the baryon to meson ratios as well as the strange to non-strange meson ratios varying with the charged particle density. By tuning the coalescence parameters, the AMPT model provides a reasonable description to the experimental data for inclusive productions of both light and charm hadrons, comparable to the string fragmentation model calculations with color reconnection effects. Additionally, we have analyzed the relative production of hadrons by examining self-normalized particle ratios as a function of the charged hadron density. Our findings suggest that parton evolution effects and the coalescence hadronization process in AMPT model lead to a strong flavor hierarchy in the multiplicity dependence of the baryon to meson ratio. Furthermore, our investigation on the $p_T$ differential double ratio of baryon to meson fraction between high and low multiplicity events indicates distinct modifications to the flavor associated baryon to meson ratio $p_T$ shape in high multiplicity events when comparing the coalescence hadronization model to the color reconnection model. These observations highlight the importance of understanding the hadronization process in high-energy proton-proton collisions through a comprehensive multiplicity dependent multi-flavor analysis.

    hep-phnucl-thNucl.Sci.Tech.(2025)·5 citations
17. 17*

    Hidden heavy flavor tetraquarks in the Born-Oppenheimer approximation

    Bowen Kang🇨🇳 · Xi Xia🇨🇳 · Tao Guo🇨🇳

    The Born-Oppenheimer approximation is one of the very successful tools for solving the hydrogen atom problem. The experimental discovery of hidden heavy flavor tetraquarks, $Q\bar{Q}q\bar{q}$ ($Q=c,b$ and $q=u,d,s$), provides great possibilities for the hydrogen-bond-like structure of the Quantum Chromodynamics version. In this work, considering that the colors of $Q\bar{Q}$ and $q\bar{q}$ are both $8$, the tetraquark $Q\bar{Q}q\bar{q}$ system is formed by color coupling $8\otimes 8\to 1$. In order to study the mass splitting caused by the color-spin hyperfine interaction, the color-spin basis vectors of the $S$-wave tetraquark states are appropriately constructed. Then we use the Born-Oppenheimer approximation to calculate the mass spectra of the $S$-wave hidden heavy flavor tetraquark states. The results show that some of the hidden heavy flavor exotic hadrons discovered experimentally can be well explained as this type of hydrogen-bond-like tetraquark structure. In addition, some candidates for tetraquark bound states are predicted and may be compact tetraquark states.

    hep-phPRD(2025)·6 citations
18. 18*

    Bottomonium meson spectrum with quenched and unquenched quark models

    M. Atif Sultan🇨🇳 · Wei Hao🇨🇳 · E. S. Swanson🇺🇸 · Lei Chang🇨🇳

    An open question in hadronic phenomenology concerns the ``unquenching" effects of higher Fock space components on the leading Fock space description of hadrons. We address this by making a comparison of the bottomonium spectrum as computed with the relativized Godfrey-Isgur quark model and an unquenched coupled channel model driven by the ``${}^3{P}_0$" mechanism of hadronic decay. Our results show that both models can describe the spectrum well, indicating that the influence of coupled channel effects can be largely absorbed into the parameters of the quenched quark model. This conclusion is reinforced by a perturbative calculation that shows that the spin-dependence of mass splittings due to mixing with the continuum recapitulates quenched quark model spin-dependent interactions. We also show that softening of the quark-antiquark wavefunction due to continuum mixing improves the description of vector bottomonium decay constants. Together, these results illustrate and substantiate the surprising robustness of simple constituent quark model descriptions of hadrons.

    hep-phEPJA(2025)·3 citations
19. 19*

    Small $x$ resummation of photon impact factors and the ${\gamma }^{\ast }{\gamma }^{\ast }$ high energy scattering

    Dimitri Colferai

    I present the renormalization group improved collinear resummation of the photon-gluon impact factors. We construct the resummed cross section for virtual photon-photon (${\gamma }^{\ast }{\gamma }^{\ast }$) scattering which incorporates the impact factors and BFKL gluon Green's function up to the next-to-leading logarithmic accuracy in energy. The impact factors include important kinematical effects which are responsible for the most singular poles in Mellin space at next-to-leading order. Further conditions on the resummed cross section are obtained by requiring the consistency with the collinear limits. Our analysis is consistent with previous impact factor calculations at NLO, apart from a new term proportional to $C_F$ that we find for the longitudinal polarization. Finally, we use the resummed cross section to compare with the LEP data on the ${\gamma }^{\ast }{\gamma }^{\ast }$ cross section and with previous calculations. The resummed result is lower than the leading logarithmic approximation but higher than the pure next-to-leading one, and is consistent with the experimental data.

    hep-phPoS(2025)·0 citations
20. 20*

    Extracting Transport Properties of Quark-Gluon Plasma from the Heavy-Quark Potential With Neural Networks in a Holographic Model

    Wen-Chao Dai🇨🇳 · Ou-Yang Luo🇨🇳 · Bing Chen🇨🇳 · Xun Chen🇨🇳 · Xiao-Yan Zhu🇨🇳 · Xiao-Hua Li🇨🇳

    Using Kolmogorov-Arnold Networks (KANs), we construct a holographic model informed by lattice QCD data. This neural network approach enables the derivation of an analytical solution for the deformation factor $w(r)$ and the determination of a constant $g$ related to the string tension. Within the KANs-based holographic framework, we further analyze heavy quark potentials under finite temperature and chemical potential conditions. Additionally, we calculate the drag force, jet quenching parameter, and diffusion coefficient of heavy quarks in this paper. Our findings demonstrate qualitative consistency with both experimental measurements and established phenomenological model.

    hep-phPLB(2026)·6 citations
21. 21*

    $D^{(\ast )}{\bar{B}}^{(\ast )}$ dynamics in chiral effective field theory

    Zhe Liu🇨🇳 · Hao Xu🇨🇳 · Xiang Liu🇨🇳

    In this work, we systematically study the interactions of the $S$-wave $D^{(\ast )}{\bar{B}}^{(\ast )}$ systems within the framework of chiral effective field theory in heavy hadron formalism. We calculate the $D^{(\ast )}{\bar{B}}^{(\ast )}$ effective potentials up to next-to-leading order, explore the bound state formations, and investigate the $D^{(\ast )}{\bar{B}}^{(\ast )}$ scattering properties such as scattering rate, scattering length, and effective range. Our results show that all $I=1$ $D^{(\ast )}{\bar{B}}^{(\ast )}$ potentials are repulsive, preventing the formation of bound states, while the $I=0$ potentials are generally attractive. Specifically, we get two important observations: first, the shallow bound state is more likely to exist in the $D\bar{B}[I(J^P)=0(0^{+})]$ system than in the $D{\bar{B}}^{\ast }[I(J^P)=0(1^{+})]$ system; second, $D^{\ast }{\bar{B}}^{\ast }[I(J^P)=0(0^{+})]$ and $D^{\ast }{\bar{B}}^{\ast }[I(J^P)=0(1^{+})]$ systems possess relatively large binding energies and positive scattering lengths, which suggests strong bound state formations in these channels. So the attractions in the $D^{\ast }{\bar{B}}^{\ast }[I=0]$ systems are deeper than those in the $D{\bar{B}}^{(\ast )}[I=0]$ systems, thus we strongly recommend the future experiment to search for the $D^{\ast }{\bar{B}}^{\ast }[I=0]$ tetraquark systems. We also investigate the coupled-channel effects on the $J=0,1$ systems and conclude that the inclusion of the coupled channels introduces small but visible influences. In addition, we also investigate the dependencies of the $D{\bar{B}}^{(\ast )}$ binding energies on the contact low-energy coupling constants.

    hep-phhep-exPRD(2025)·5 citations
22. 22*

    Mass and width of $T_{c\bar{c}}(4020)$ in the developed Bethe-Salpeter theory

    Xiaozhao Chen🇨🇳 · Xiaofu Lü🇨🇳 · Xiurong Guo🇨🇳 · Zonghua Shi🇨🇳

    In experiments exotic meson resonance $T_{c\bar{c}}(4020)$ lies above the $D^{\ast }{\bar{D}}^{\ast }$ threshold, and in principle one can not explain $T_{c\bar{c}}(4020)$ as a meson-meson bound state because meson-meson bound state must lie below the $D^{\ast }{\bar{D}}^{\ast }$ threshold. In this work, exotic resonance $T_{c\bar{c}}(4020)$ is considered as an unstable meson-meson molecular state $D^{\ast }{\bar{D}}^{\ast }$, and the developed Bethe-Salpeter theory for dealing with unstable state is applied to investigate resonance $T_{c\bar{c}}(4020)$. We calculate the mass and width of unstable meson-meson molecular state $D^{\ast }{\bar{D}}^{\ast }$ in the framework of relativistic quantum field theory and find that this unstable meson-meson molecular state lies above the $D^{\ast }{\bar{D}}^{\ast }$ threshold, which is consistent with experimental values of resonance $T_{c\bar{c}}(4020)$.

    hep-phEPJC(2026)·0 citations
23. 23*

    Reappraisal of rho meson in nuclear matter by inverse QCD sum rules method

    Halil Mutuk🇹🇷

    We present a comprehensive reappraisal of the in-medium properties of the rho meson using the inverse QCD sum rules (QCDSR) formalism, offering a novel, model-independent approach to studying hadronic modifications in nuclear matter. Unlike conventional QCDSR, which rely on a predefined pole+continuum structure, the inverse method reconstructs the spectral function directly from the operator product expansion (OPE), eliminating assumptions about the spectral ansatz. To the best of our knowledge, this is the first application of the inverse QCDSR method to the rho meson in nuclear matter. Our analysis reveals a significant reduction in the rho meson mass, consistent with previous theoretical predictions, and highlights the crucial role of medium-induced modifications, including condensate suppression and factorization-breaking effects. Furthermore, we assess the sensitivity of our results to the factorization assumption and higher-dimensional condensates, demonstrating the necessity of refining nonperturbative contributions for an accurate description of in-medium hadron properties. Our findings establish the inverse QCDSR method as a robust alternative to conventional spectral analysis techniques, providing a systematically controlled framework for exploring strongly interacting matter under extreme conditions. These results offer important theoretical benchmarks for lattice QCD simulations and heavy-ion collision experiments, shedding light on the restoration of chiral symmetry and the evolution of hadronic matter in dense environments.

    hep-phhep-exhep-latPRD(2025)·6 citations
24. 24*

    Self-interaction effects on the Kerr black hole superradiance and their observational implications

    Ning Xie🇨🇳 · Fa Peng Huang🇨🇳

    Through the black hole (BH) superradiance, ultralight bosons can form dense clouds around rotating Kerr BHs. Certain ultralight bosons, such as axions and axion-like particles (promising dark matter candidates), naturally possess self-interactions, and thus may significantly modify the dynamics of the superradiance process. Previous studies on the detection or constraint of ultralight bosons through superradiance have usually neglected the self-interaction effects of bosons. In this work, we investigate the formation and evolution of self-interacting boson clouds in the full Kerr spacetime during BH superradiance. Using numerical methods, we compute the superradiant growth rate of boson clouds with self-interactions around Kerr BHs and quantitatively evaluate how the self-interaction strength of scalar bosons affects the growth rate. We also assess the evolution of the BH's mass and spin. Our results reveal that, in addition to the superradiance-imposed upper bound on the boson cloud mass, self-interaction of ultralight bosons introduces a new, lower critical mass limit, beyond which the growth rate of the boson cloud approaches zero. This implies that the superradiance process terminates earlier when self-interaction is considered. Furthermore, we explore how self-interaction affects both the oscillation frequency of boson clouds in gravitational atoms and the frequency of gravitational wave (GW) emitted through cloud annihilation. The anticipated frequency shift might be detectable by the GW observatories. Given that self-interaction substantially alters the evolution of BH superradiance, its effects can significantly relax existing constraints on scalar bosons derived from superradiance. Taking the spin measurements from GW190412 and GW190517 as examples, we discuss the impact of self-interaction on constraint results in details.

    hep-phPRD(2025)·14 citations
25. 25*

    Does thermal leptogenesis in a canonical seesaw rely on initial memory?

    Partha Kumar Paul🇮🇳 · Narendra Sahu🇮🇳 · Shashwat Sharma🇮🇳

    It is a common lore that in thermal leptogenesis within the type-I seesaw framework and a hierarchical spectrum of heavy right-handed neutrinos (RHNs), the CP-violating, out-of-equilibrium decay of the lightest RHN ($N_1$) is the only relevant source of the final $B-L$ asymmetry, since any asymmetry produced by the heavier RHNs is expected to be erased by subsequent $N_1$-mediated washout processes. In this work, we revisit this assumption by solving the density-matrix equations, including decay, inverse decay, and relevant scattering processes, and by fully accounting for flavor-projection effects induced by the Yukawa coupling structure. We show that the asymmetries generated by the heavier RHNs ($N_2$ and $N_3$) generally possess components that are misaligned in flavor space with respect to $N_1$, resulting in a partially protected contribution that survives the $N_1$ washout. Unlike the conventional picture of $N_2$-dominated leptogenesis, this memory effect arises even when $N_1$ remains dynamically relevant and cannot be captured within the classical Boltzmann framework. Furthermore, imposing consistency with low-energy neutrino mass and mixing data, we find that at most one RHN can lie in the weak washout regime, which naturally divides the parameter space into four distinct dynamical regimes. We systematically quantify the memory effect in each regime and demonstrate that it can significantly modify the final $B-L$ asymmetry. We find that including projection effects can indeed extend the viable parameter space into the sensitivity range of neutrinoless double beta decay experiments.

    hep-phastro-ph.COhep-thPRD(2026)·2 citations
26. 26*

    Hadron physics with functional methods

    Gernot Eichmann🇦🇹

    We give a pedagogical introduction to hadron spectroscopy and structure studies using functional methods. We explain the basic features of Dyson-Schwinger, Bethe-Salpeter and Faddeev equations, which are employed to calculate the spectra of mesons, baryons and four-quark states. We discuss dynamical mass generation as a consequence of the spontaneous breaking of chiral symmetry, which is intertwined with the emergence of the light pions as Goldstone bosons of QCD. We highlight the importance of diquark correlations in the baryon sector, while for four-quark states such as the light scalar mesons and heavy exotics the dominant two-body clusters are typically mesons. We conclude with a brief discussion of hadron matrix elements like electromagnetic form factors and how vector-meson dominance is an automatic outcome of functional equations.

    hep-phnucl-th23 citations
27. 27*

    Background processes in Higgs decay to Z gamma

    Aliaksei Kachanovich🇧🇪

    The ATLAS and CMS Collaborations reported that the observed number of Higgs boson decays into a $Z$ boson and a photon is $\mu =2.2\pm 0.7$ times higher than predicted by the Standard Model. Initially, this discrepancy was attributed to a modification of the $HZ\gamma$ vertex. In the $H\to Z\gamma$ process, this decay is reconstructed from $H\to \ell \ell \gamma$, where $\ell$ represents either an electron or a muon. In this study, an investigation is conducted to examine this anomaly by exploring potential additional background contributions to $H\to \ell \ell \gamma$ from various subprocesses within and beyond the Standard Model.

    hep-phhep-exPoS(2025)·1 citation
28. 28*

    Pion transverse charge density from $e^{+}$$e^{-}$ annihilation data and logarithmic dispersion relations

    Enrique Ruiz Arriola🇪🇸 · Pablo Sanchez-Puertas🇪🇸 · Christian Weiss🇺🇸

    The transverse charge density of the pion is extracted from a dispersive analysis of the $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}$ exclusive annihilation data. A logarithmic dispersion relation is used to compute the unknown phase of the timelike pion form factor from the modulus obtained from the annihilation cross section. The method is model-independent and permits quantitative uncertainty estimates. The density is obtained with few-percent accuracy down to $b\sim 0.1$ fm; at smaller distances it depends qualitatively on the assumed high-energy behavior of the timelike form factor. Implications for pion structure and the relevance of pQCD asymptotics are discussed.

    hep-phPLB(2025)·6 citations
29. 29*

    Chiral Magnetic Effect enhancement at lower collision energies

    Sebastian Grieninger🇺🇸 · Sergio Morales-Tejera🇷🇴 · Pau G. Romeu🇪🇸

    We extend previous holographic studies of the Chiral Magnetic Effect (CME) by incorporating a time-dependent magnetic field. Various magnetic field profiles proposed in the literature are implemented, and their impact on the CME signal is analyzed in both static and expanding backgrounds. Interestingly, the integrated chiral magnetic current can exhibit a non-monotonic dependence on the collision energy. Our results suggest that the CME signal is enhanced at collision energies below $\sqrt{s}=200$ GeV. In addition, we derive a quasi-equilibrium formula for the chiral magnetic effect in the expanding background that is valid at late times.

    hep-phhep-thnucl-thPRD(2025)·3 citations
30. 30*

    Compact Two-Loop QCD Corrections for $Vjj$ Production in Proton Collisions

    Giuseppe De Laurentis🇬🇧 · Harald Ita🇨🇭 · Ben Page🇧🇪 · Vasily Sotnikov🇨🇭

    We present compact two-loop QCD corrections in the leading-color approximation for the production of an electroweak vector boson, $V=\{W^{\pm },Z,{\gamma }^{\star }\}$, in association with two light jets ($Vjj$) at hadron colliders. Leptonic decays of the electroweak boson are included at the amplitude level. Working in the analytic-reconstruction approach, we develop two techniques to build compact partial-fraction forms for individual rational functions. One approach exploits their analytic structure. In the other, we iteratively construct subtraction terms that match the rational functions in singular limits. Moreover, we show how the singular behavior of the rational functions can be systematically used to find a more compact basis of the space that they span. We apply our techniques to the $Vjj$ amplitudes, yielding a representation that is three orders of magnitude smaller than previous results. We then use these compact expressions to provide an efficient and stable C++ numerical implementation suitable for phenomenological applications.

    hep-phhep-thJHEP(2025)·22 citations
31. 31*

    Could We Observe an Exploding Black Hole in the Near Future?

    Michael J. Baker🇺🇸 · Joaquim Iguaz Juan🇺🇸 · Aidan Symons🇺🇸 · Andrea Thamm🇺🇸

    Observation of an exploding black hole would provide the first direct evidence of primordial black holes, the first direct evidence of Hawking radiation, and definitive information on the particles present in nature. However, indirect constraints suggest that direct observation of an exploding Schwarzschild black hole is implausible. We introduce a dark-QED toy model consisting of a dark photon and a heavy dark electron. In this scenario a population of light primordial black holes charged under the dark $u(1)$ symmetry can become quasi-extremal, so they survive much longer than if they were uncharged, before discharging and exhibiting a Schwarzschild-like final explosion. We show that the answer is "yes", in this scenario the probability of observing an exploding black hole over the next $10$ years could potentially be over $90\%$.

    hep-phastro-ph.COPRL(2025)·17 citations
32. 32*

    Pre-thermalized Gravitational Waves

    Nicolás Bernal🇦🇪 · Quan-feng Wu🇨🇳 · Xun-Jie Xu🇨🇳 · Yong Xu🇨🇳

    We investigate a novel gravitational wave (GW) production mechanism from gravitons generated during the pre-thermal phase of cosmic reheating, where the energy density is dominated by non-thermalized inflaton decay products, dubbed reheatons. We consider multiple production channels, including: $i)$ pure inflaton-inflaton annihilation, $ii)$ graviton Bremsstrahlung from inflaton decay, $iii)$ scatterings between an inflaton and a reheaton, and $iv)$ scatterings among reheatons. To determine the resulting GW spectrum, we solve the Boltzmann equation to obtain the graviton phase-space distribution for each channel. We find that the third channel, $iii)$, dominates due to the large occupation number of reheatons at highly-energetic states during the pre-thermalization phase. Notably, in scenarios with a low inflaton mass, the GW spectrum could fall within the sensitivity range of future experiments such as the Einstein Telescope, the Cosmic Explorer, the Big Bang Observer, and ultimate DECIGO.

    hep-phastro-ph.COJHEP(2025)·22 citations
33. 33*

    Results from an Einstein@Home search for continuous gravitational waves from Cassiopeia A and Vela Jr. using LIGO O2 data

    Jorge Morales🇺🇸 · Jing Ming🇩🇪 · Maria Alessandra Papa🇩🇪 · Heinz-Bernd Eggenstein🇩🇪 · Bernd Machenschalk🇩🇪

    We conduct two searches for continuous, nearly monochromatic gravitational waves originating from the central compact objects in the supernova remnants Cassiopeia A and Vela Jr. using public LIGO data. The search for Cassiopeia A targets signal frequencies between 20 Hz and 400 Hz; the Vela Jr. search between 400 Hz and 1700 Hz, and both investigate the broadest set of waveforms ever considered with highly sensitive deterministic search methods. Above 1500 Hz the Vela Jr. search is the most sensitive carried out thus far, improving on previous results by over 300\%. Above 976 Hz these results improve on existing ones by 50\%. In all we investigate over $10^{18}$ waveforms, leveraging the computational power donated by thousands of Einstein@Home volunteers. We perform a 4-stage follow-up on more than 6 million waveforms. None of the considered waveforms survives the follow-up scrutiny, indicating no significate detection candidate. Our null results constrain the maximum amplitude of continuous signals as a function of signal frequency from the targets. The most stringent 90\% confidence upper limit for Cas A is $h_0^{90\%}\approx 7.3\times 10^{-26}$ near 200 Hz, and for Vela Jr. it is $h_0^{90\%}\approx 8.9\times 10^{-26}$ near 400 Hz. Translated into upper limits on the ellipticity and r-mode amplitude, our results probe physically interesting regions: for example the ellipticity of Vela Jr. is constrained to be smaller than $10^{-7}$ across the frequency band, with a tighter constraint of less than $2\times 10^{-8}$ at the highest frequencies.

    ↳ gr-qchep-ph4 citations
34. 34*

    $bb\bar{u}\bar{d}$ and $bs\bar{u}\bar{d}$ tetraquarks from lattice QCD using two-meson and diquark-antidiquark variational basis

    Bhabani Sankar Tripathy🇮🇳 · Nilmani Mathur🇮🇳 · M. Padmanath🇮🇳

    We present a lattice QCD investigation of isoscalar tetraquark systems involving bottom quarks with explicit flavor content $bb\bar{u}\bar{d}$ and $bs\bar{u}\bar{d}$. In the doubly bottom sector, the study focuses on axialvector $J^P=1^{+}$ quantum numbers, whereas in the $bs\bar{u}\bar{d}$ channel both axial vector $J^P=1^{+}$ and scalar $J^P=0^{+}$ quantum numbers are investigated in search of signatures for possible tetraquark bound states. The calculations are performed on four ensembles with dynamical quark fields up to the charm quark generated by the MILC Collaboration, with lattice spacings ranging from approximately 0.058 fm to 0.12 fm, and at different values of the valence light quark mass $m_{u/d}$, corresponding to pseudoscalar meson masses, $M_{ps}$=0.5, 0.6 and 0.7 GeV. The energy eigenvalues in the finite volume are determined by applying a variational procedure to correlation matrices constructed from two-meson interpolating operators and diquark-antidiquark operators. Continuum extrapolated elastic $S$-wave scattering amplitudes of $B{B}^{\ast }$, $K{B}^{\ast }$ and $KB$ are extracted from the ground state eigenenergies following a finite-volume analysis á la Lüscher. The chiral and continuum extrapolated binding energy estimates for the isoscalar axialvector doubly bottom tetraquark $T_{bb}$ from the extracted elastic $B{B}^{\ast }$ $S$-wave scattering amplitudes is found to be $\Delta E_{T_{bb}}(1^{+})=-116{(}_{-36}^{+30})$ MeV. In the $bs\bar{u}\bar{d}$, no statistically significant deviations were observed in the ground state energies from the respective elastic threshold energies, leading to no conclusive evidence for any bound states.

    ↳ hep-lathep-exhep-phPRD(2025)·16 citations
35. 35*

    Renormalising the Field-Space Geometry

    Patrick Aigner🇩🇪 · Luigi Bellafronte🇺🇸 · Emanuele Gendy🇩🇪 · Dominik Haslehner🇩🇪 · Andreas Weiler🇩🇪

    We present a systematic study of one-loop quantum corrections in scalar effective field theories from a geometric viewpoint, emphasizing the role of field-space curvature and its renormalisation. By treating the scalar fields as coordinates on a Riemannian manifold, we exploit field redefinition invariance to maintain manifest coordinate independence of physical observables. Focusing on the non-linear sigma model (NLSM) and \(\phi^4\) theory, we demonstrate how loop corrections induce momentum- and scale-dependent shifts in the curvature of the field-space manifold. These corrections can be elegantly captured through the recently proposed geometry-kinematics duality, which generalizes the colour-kinematics duality in gauge theories to curved field-space backgrounds. Our results highlight a universal structure emerging in the contractions of Riemann tensors that contribute to renormalisation of the field-space curvature. In particular, we find explicit expressions and a universal structure for the running curvature and Ricci scalar in simple models, illustrating how quantum effects reshape the underlying geometry. This geometric formulation unifies a broad class of scalar EFTs, providing insight into the interplay of curvature, scattering amplitudes, and renormalisation.

    ↳ hep-thhep-phJHEP(2025)·13 citations
36. 36*

    Signs of Non-Monotonic Finite-Volume Corrections to $g_A$

    Zack B. Hall🇺🇸 · Dimitra A. Pefkou🇺🇸 · Aaron S. Meyer🇺🇸 · Thomas R. Richardson🇺🇸 · Raúl A. Briceño🇺🇸 · M. A. Clark🇺🇸 · Martin Hoferichter🇨🇭 · Emanuele Mereghetti🇺🇸 · Henry Monge-Camacho🇺🇸 · Colin Morningstar🇺🇸 · Amy Nicholson🇺🇸 · Pavlos Vranas🇺🇸 · André Walker-Loud🇺🇸

    We study finite-volume (FV) corrections to determinations of $g_A$ via lattice quantum chromodynamics (QCD) using analytic results and numerical analysis. We observe that $SU(2)$ Heavy Baryon Chiral Perturbation Theory does not provide an unambiguous prediction for the sign of the FV correction, which is not surprising when one also considers large-$N_c$ constraints on the axial couplings. We further show that non-monotonic FV corrections are naturally allowed when one considers either including explicit $\Delta$-resonance degrees of freedom or one works to higher orders in the chiral expansion. We investigate the potential impact of these FV corrections with a precision study of $g_A$ using models of FV corrections that are monotonic and non-monotonic. Using lattice QCD data that is approximately at the 1% level of precision, we do not see significant evidence of non-monotonic corrections. Looking forward to the next phase of lattice QCD calculations, we estimate that calculations that are between the 0.1%-1%-level of precision may be sensitive to these FV artifacts. Finally, we present an update of the CalLat prediction of $g_A$ in the isospin limit with sub-percent precision, $g_A^{\mathrm{QCD}}=1.2674(96)$.

    ↳ hep-lathep-phnucl-exnucl-thPRC(2026)·21 citations
37. 37*

    Modified gravity constraints with Planck ISW-lensing bispectrum

    Anton Chudaykin🇨🇭 · Martin Kunz🇨🇭 · Julien Carron🇨🇭

    We present updated constraints on modified gravity by including the Integrated Sachs-Wolfe (ISW) effect from CMB lensing-CMB temperature cross-correlations, based on the latest Planck PR4 maps. Utilizing the Effective Field Theory of dark energy approach and adopting the $w_0{w}_a$CDM background cosmological model, we find that including the CMB ISW lensing cross-correlations tighten constraints on the modified gravity parameters by approximately $20\%$, reducing the viable parameter space by $40-80\%$. We derive constraints from Planck CMB, Planck and ACT CMB lensing, DESI DR1 BAO, CMB ISW-lensing, and type Ia supernovae (SN Ia) data. The constraints on the EFT parameters controlling the kinetic braiding and non-minimal coupling are consistent with General Relativity (GR) at the $95\%$ CL. In particular, we obtain a bound on the kinetic braiding parameter, $c_B<1.2$ at $95\%$ CL. In the $w_0$-$w_a$ parameter space, our results imply a crossing of the phantom divide, $w=-1$. The modified gravity model shows a mild preference over $\Lambda$CDM at the $1.8\sigma$, $2.6\sigma$ and $3.2\sigma$ levels for the combinations with Pantheon+, Union3 and DESY5 supernova datasets. We find that using the latest $\text{HiLLiPoP}+\text{LoLLiPoP}$ likelihoods alleviates the departure of modified gravity parameters from the GR-values compared to results using {\it Planck} 2018 data. This paper underlines the importance of the ISW lensing probe in constraining late-time modifications of gravity.

    ↳ astro-ph.COhep-phPRD(2025)·21 citations
38. 38*

    Beyond the Boltzmann equation for weakly coupled quantum fields

    Xu-Yao Hu🇨🇳 · Vladimir Rosenhaus🇺🇸

    We study the kinetic theory of a weakly interacting quantum field. Assuming a state that is close to homogeneous and stationary, we derive a closed kinetic equation for the rate of change of the occupation numbers, perturbatively in the coupling. For a dilute gas, this reproduces the quantum Boltzmann equation, which only accounts for two-to-two scattering processes. Our expression goes beyond this, with terms accounting for multi-particle scattering processes, which are higher order in the density.

    ↳ hep-thcond-mat.stat-mechhep-phphysics.flu-dynJHEP(2025)·2 citations
39. 39*

    Bayesian analysis of a (3+1)D hybrid approach with initial conditions from hadronic transport

    Niklas Götz🇩🇪 · Iurii Karpenko🇨🇿 · Hannah Elfner🇩🇪

    This study aims to apply statistical learning, specifically Bayesian inference, to the (3+1)D SMASH-vHLLE-hybrid model using initial conditions generated by the SMASH transport code itself, with the objective of constraining model parameters and gaining deeper insight on the temperature and baryochemical potential dependence of both the shear and the bulk viscosity. This study is performed in the hybrid approach SMASH-vHLLE, composed of the hadronic transport approach SMASH and the (3+1)D viscous hydrodynamic code vHLLE. A Bayesian framework is employed, utilizing Markov Chain Monte Carlo (MCMC) sampling to explore the parameter space. The analysis compares model predictions against experimental observables, including particle yields, momentum and flow coefficients both at midrapidity as well as in forward and backward direction. We find that the SMASH-vHLLE-hybrid framework, using hadronic initial conditions for Au+Au collisions at different beam energies, can reproduce a variety of experimental observables at midrapidity and forward/backward rapidities. Notably, the preferred posterior distribution suggests a near-vanishing specific shear viscosity in the high-temperature QGP phase, combined with moderate-to-large bulk viscosity around the phase transition region, although the constraints on baryochemical potential dependence are weak. Our findings reveal that a hadronic initial condition constrains the evolution more strictly at intermediate energies, making parameters such as the hydrodynamic onset time highly sensitive. Intriguingly, the extracted shear viscosity differs substantially from previous Bayesian analyses, motivating further systematic studies with higher-statistics data sets and refined modeling assumptions.

    ↳ nucl-thhep-phnucl-exPRC(2025)·21 citations
40. 40*

    Model-independent $H_0$ within FLRW: Joint constraints from GWTC-3 standard sirens and strong lensing time delays

    Ji-Yu Song🇺🇸 · Jing-Zhao Qi🇺🇸 · Jing-Fei Zhang🇺🇸 · Xin Zhang🇺🇸

    We use 47 gravitational-wave (GW) standard sirens from the third Gravitational-Wave Transient Catalog to calibrate distances in the strong gravitational lensing (SGL) system RXJ1131-1231 and constrain the Hubble constant ($H_0$) via the distance sum rule, without assuming a specific cosmological model. For ${\Omega }_K=0$, we obtain $H_0=73.22_{-5.43}^{+5.95}$ $\mathrm{km}{\mathrm{s}}^{-1}{\mathrm{Mpc}}^{-1}$ and $H_0=70.40_{-5.60}^{+8.03}$ $\mathrm{km}{\mathrm{s}}^{-1}{\mathrm{Mpc}}^{-1}$ by breaking the mass-sheet transform using lens galaxy's mass models and stellar kinematics, respectively. Allowing ${\Omega }_K$ to vary increases the central value of $H_0$ and reduces its precision. We find that GW dark sirens have significant potential for calibrating SGL systems, due to their relatively higher redshifts. By combining 42 binary black holes and RXJ1131-1231, we obtain an $H_0$ constraint with a precision approximately $40\%$ better than the measurement from GW170817 using the Hubble law. This suggests that high-precision, model-independent $H_0$ measurements can be achieved with this method as the redshift range of GW dark sirens expands, even without the need for GW bright sirens.

    ↳ astro-ph.COgr-qchep-phhep-thApJL(2025)·32 citations
41. 41*

    The stochastic gravitational wave background from cosmic superstrings

    Anastasios Avgoustidis🇬🇧 · Edmund J. Copeland🇬🇧 · Adam Moss🇬🇧 · Juhan Raidal🇬🇧

    We study the stochastic gravitational wave background sourced by a network of cosmic superstrings and demonstrate that incorporating higher-mass string species, beyond the fundamental string, is crucial for accurately modelling the resulting gravitational wave spectrum across frequencies ranging from nanohertz to kilohertz. Using the multi-tension velocity-dependent one-scale model to evolve the cosmic superstring network, we perform several fits to the NANOGrav 15-year dataset and obtain expectation values for the fundamental string tension, string coupling and effective size of compact extra dimensions. We find that the cosmic superstring best-fits are comparable in likelihood to Supermassive Black Hole models, thought by many to be the leading candidate explanation of the signal. The implications of the best-fit spectra are discussed within the context of future gravitational wave experiments. We obtain expectation values for the fundamental string tension of ${\log }_{10}(G{\mu }_1)=-11.4_{-0.2}^{+0.3}$($-11.5_{-0.2}^{+0.3}$) for gravitational waves originating from large cuspy (kinky) cosmic superstring loops and ${\log }_{10}(G{\mu }_1)=-9.7_{-0.7}^{+0.7}$($-9.9_{-0.5}^{+1.0}$) for small cuspy (kinky) loops. We also place $2\sigma$ upper bounds on the string coupling, finding $g_s<0.7$ in all cases, and comment on the implication of our results for the effective size of the compact extra dimensions.

    ↳ astro-ph.COastro-ph.HEgr-qchep-ph+1JCAP(2025)·15 citations
42. 42*

    A search for sterile neutrinos in interacting dark energy models using DESI baryon acoustic oscillations and DES supernovae data

    Lu Feng🇨🇳 · Tian-Nuo Li🇺🇸 · Guo-Hong Du🇺🇸 · Jing-Fei Zhang🇺🇸 · Xin Zhang🇺🇸

    Sterile neutrinos can influence the evolution of the universe, and thus cosmological observations can be used to search for sterile neutrinos. In this study, we utilized the latest baryon acoustic oscillations data from DESI, combined with the cosmic microwave background data from Planck and the five-year supernova data from DES, to constrain the interacting dark energy (IDE) models involving both cases of massless and massive sterile neutrinos. We consider four typical forms of the interaction term $Q=\beta H{\rho }_{\mathrm{de}}$, $Q=\beta H{\rho }_{\mathrm{c}}$, $Q=\beta H_0{\rho }_{\mathrm{de}}$, and $Q=\beta H_0{\rho }_{\mathrm{c}}$, respectively. Our analysis indicates that the current data provide only a hint of the existence of massless sterile neutrinos (as dark radiation) at about the $1\sigma$ level. In contrast, no evidence supports the existence of massive sterile neutrinos. Furthermore, in IDE models, the inclusion of (massless/massive) sterile neutrinos has a negligible impact on the constraint of the coupling parameter $\beta$. The IDE model of $Q=\beta H{\rho }_{\mathrm{c}}$ with sterile neutrinos does not favor an interaction. However, the other three IDE models with sterile neutrinos support an interaction in which dark energy decays into dark matter.

    ↳ astro-ph.COgr-qchep-phhep-thPhys.Dark Univ.(2025)·42 citations
43. 43*

    Self-interacting neutrinos in light of recent CMB and LSS data

    Adèle Poudou🇫🇷 · Théo Simon🇫🇷 · Thomas Montandon🇫🇷 · Elsa M. Teixeira🇫🇷 · Vivian Poulin🇫🇷

    We update constraints on a simple model of self-interacting neutrinos involving a heavy scalar mediator with universal flavor coupling. According to past literature, such a model is allowed by Cosmic Microwave Background (CMB) data, with some CMB and large-scale structure data even favoring a strongly-interacting neutrino (SI$\nu$) scenario over $\Lambda$CDM. In this work, we re-evaluate the constraints on this model in light of the new Planck NPIPE data, DESI BAO data, and the Effective Field Theory of Large Scale Structures (EFTofLSS) applied to BOSS data. We find that Planck NPIPE are more permissive to the SI$\nu$ scenario and that DESI data favor the SI$\nu$ over $\Lambda$CDM. However, when considering EFTofBOSS data, this mode is no longer preferred. Therefore, new DESI data analyzed under the EFTofLSS are particularly awaited to shed light on this disagreement.

    ↳ astro-ph.COhep-phPRD(2025)·32 citations
44. 44*

    Explanation of the observed violation of isospin symmetry in relativistic nucleus-nucleus reactions

    Tom Reichert🇩🇪 · Jan Steinheimer🇩🇪 · Marcus Bleicher🇩🇪

    The violation of isospin symmetry in nucleus-nucleus reactions, as shown in the ratio $R_K=(K^{+}+K^{-})/(K^0+{\bar{K}}^0)$ presented by NA61/SHINE, can be understood by introducing results from color-string fragmentation in $e^{+}{e}^{-}$ to nuclear reactions. This novel input allows for a consistent description of the $e^{+}{e}^{-}$ data, proton+proton data and finally nucleus-nucleus data at all investigated energies. We conclude that the observed isospin violation in nucleus-nucleus reactions is explained by asymmetric production of up- and down-quarks in the elementary color field fragmentation process.

    ↳ nucl-thhep-phnucl-exPLB(2026)·7 citations
45. 45*

    Apparent teleportation of indistinguishable particles

    Marek Gazdzicki🇵🇱 · Daniel Kikola🇵🇱 · Ivan Pidhurskyi🇵🇱 · Leonardo Tinti🇵🇱

    Teleportation, introduced in science fiction literature, is an instantaneous change of the position of a macroscopic object. Two teleportation-like phenomena have been predicted by quantum mechanics: quantum teleportation and, more recently, quantum particle teleportation. Here, we introduce the third teleportation-like phenomenon - apparent teleportation. It seems to be a natural consequence of the Standard Model's indistinguishable elementary particles and antiparticles. We illustrate the idea within a 1+1D toy model of particle-antiparticle creation and space-time evolution obeying transport locality. Furthermore, we propose a novel method to observe apparent teleportation driven by strong interactions through measurements of correlations between the momenta of charm and anticharm hadrons in nuclear collisions. Observing the apparent teleportation would uncover the basic transport properties of indistinguishable particles.

    ↳ nucl-thhep-phquant-phActa Phys.Polon.B(2026)·2 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.