Thu·Sep 26, 2024Thursday·September 26, 2024

1. 01*

   Threshold resummation for $Z$-boson pair production at NNLO+NNLL

   Pulak Banerjee🇮🇹 · Chinmoy Dey🇮🇳 · M. C. Kumar🇮🇳 · Vaibhav Pandey🇮🇳

   The production of a pair of on-shell $Z$-bosons is an important process at the Large Hadron Collider. Owing to its large production cross section at the LHC, this process is very useful for SM precision studies, electroweak symmetry breaking sector as well as to unravel the possible new physics. In this work, we have performed the threshold resummation of the large logarithms that arise in the partonic threshold limit $z\to 1$, up to Next-to-Next-to-Leading Logarithmic (NNLL) accuracy. The presence of the two-loop contributions in the process dependent resummation coefficient $g_0$ makes the numerical computation a non-trivial task. After matching the resummed predictions to the Next-to-Next-to-Leading order (NNLO) fixed order results, we present the invariant mass distribution to NNLO+NNLL accuracy in QCD for the current LHC energies. We find that in the high invariant mass region ($Q=1$ TeV), while the NNLO corrections are as large as $83\%$ with respect to the leading order, the NNLL contribution enhances the cross section by additional few percent, about $4\%$ for $13.6$ TeV LHC. In this invariant mass region, the conventional scale uncertainties in the fixed order results get reduced from $3.4\%$ at NNLO to about $2.6\%$ at NNLO+NNLL, and this reduction is expected to be more for higher $Q$ values.

   hep-phhep-exPRD(2026)·8 citations
2. 02*

   KrkNLO matching for colour-singlet processes

   Pratixan Sarmah🇵🇱 · Andrzej Siódmok🇵🇱 · James Whitehead🇵🇱

   Matched calculations combining perturbative QCD with parton showers are an indispensable tool for LHC physics. Two methods for NLO matching are in widespread use: MC@NLO and POWHEG. We describe an alternative, KrkNLO, reformulated to be easily applicable to any colour-singlet process. The primary distinguishing characteristic of KrkNLO is its use of an alternative factorisation scheme, the 'Krk' scheme, to achieve NLO accuracy. We describe the general implementation of KrkNLO in Herwig 7, using diphoton production as a test process. We systematically compare its predictions to those produced by MC@NLO with several different choices of shower scale, both truncated to one-emission and with the shower running to completion, and to ATLAS data from LHC Run 2.

   hep-phJHEP(2025)·13 citations
3. 03*

   Radioactivity of Quark Nuggets

   Yang Bai🇺🇸 · Mrunal Korwar🇺🇸

   Quark nuggets ${}_Z^{A}Q$, as Fermionic non-topological solitons, could have their mass per baryon smaller than ordinary nuclei and behave as exotic nuclei with different relations of atomic number and atomic mass number. Using both the degenerate Fermi gas model and the Friedberg-Lee shell model, we calculate the properties of quark nuggets made of up and down quarks. Similar to ordinary nuclei, quark nuggets could exhibit their own radioactivity, including gamma decay, beta decay, and (explosive) spontaneous fission, with the qualitative properties presented here. These quark nugget properties may provide guidance for searching for quark nuggets in situ from binary neutron star mergers.

   hep-phastro-ph.HEnucl-thJHEP(2025)·7 citations
4. 04*

   Disoriented isospin condensates in heavy-ion collisions

   Joseph Kapusta🇺🇸 · Scott Pratt🇺🇸 · Mayank Singh🇺🇸

   Anomalous neutral to charged kaon correlations measured by the ALICE collaboration have defied usual explanations. We propose that the large fluctuations could arise because of a disoriented isospin condensate where there is an imbalance between up and down condensates at the time kaons hadronize. This could happen in heavy-ion collisions when the quark condensate re-forms as the system cools and the approximate chiral symmetry of QCD is broken. Within the linear sigma model, we show that the energy cost of forming a disoriented isospin condensate is small making it very plausible.

   hep-phnucl-thEPJ Web Conf.(2025)·0 citations
5. 05*

   Spinodal decomposition in Bjorken flow

   Joseph Kapusta🇺🇸 · Mayank Singh🇺🇸 · Thomas Welle🇺🇸

   The QCD first-order phase transition at large baryon densities is expected to proceed by spinodal decomposition. This spinodal phase is likely to leave its signatures on the experimental observables measured in heavy-ion collision experiments. Identifying these signatures requires phenomenological models integrating surface effects resulting from the phase transition into the hydrodynamical description of the expanding quark gluon plasma. We write the equations of relativistic hydrodynamics with spinodal decomposition and solve it in on a background of Bjorken flow relevant for heavy-ion collisions.

   hep-phnucl-thEPJ Web Conf.(2025)·3 citations
6. 06*

   Single Production of Doubly Charged Higgs at Muon Collider

   Jie-Cheng Jia🇨🇳 · Zhi-Long Han🇨🇳 · Fei Huang🇨🇳 · Yi Jin🇨🇳 · Honglei Li🇨🇳

   In this paper, we study the single production of doubly charged Higgs $H^{\pm \pm }$ in the type-II seesaw at the high energy muon collider. Compared with the pair production channel ${\mu }^{+}{\mu }^{-}\to H^{++}{H}^{--}$, the single production channel ${\mu }^{+}{\mu }^{-}\to {\mu }^{\mp }{\ell }^{\mp }{H}^{\pm \pm }$ in principle could probe the mass region above the threshold $m_{H^{\pm \pm }}>\sqrt{s}/2$. The single production channel depends on the Yukawa coupling $h$, which is related to the neutrino oscillation parameters. We show that the Majorana phases ${\varphi }_1$ and ${\varphi }_2$ have great impact on the individual cross section of the single production. We find that the same sign dilepton signature from $H^{\pm \pm }\to {\ell }^{\pm }{\ell }^{\pm }$ could probe $m_{H^{\pm \pm }}\lesssim 2.6(7.1)$ TeV at the 3 (10) TeV muon collider when the triplet VEV $v_{\Delta }\lesssim 3$ eV.

   hep-phhep-exPRD(2025)·11 citations
7. 07*

   Lepton-flavor violation in the left-right supersymmetric standard model

   Yong-Kang Huang🇨🇳 · Jin-Lei Yang🇨🇳 · Sheng-Kai Cui🇨🇳 · Tai-Fu Feng🇨🇳

   In the Standard Model (SM), the charged lepton-flavor violation (CLFV) processes are forbidden, so the observation of CLFV represents a clear signal of new physics that goes beyond the Standard Model. In this work, we focus on the CLFV processes $l_j^{-}\to l_i^{-}\gamma$ and $l_j^{-}\to l_i^{-}{l}_i^{-}{l}_i^{+}$ in LRSSM. Considering the constraints of the updated experimental datas, the numerical results show that the new contributions of $SU{\left(2\right)}_R$ gauge interaction and a large number of other new particles, such as $Z^{{}^{\prime }}$ boson, double-charged Higgs-bosons in LRSSM can make significant contributions to the CLFV processes $l_j^{-}\to l_i^{-}\gamma$ and $l_j^{-}\to l_i^{-}{l}_i^{-}{l}_i^{+}$, which is much different from the ones predicted in other SUSY models. This work provide a theoretical base for finding the LFV phenomena in new physics.

   hep-phPRD(2024)·4 citations
8. 08*

   Determination of the $K^{+}{\bar{K}}^0$ scattering length and effective range and its relation to the $a_0^{+}(980)$ from the ${\chi }_{c1}\to {\pi }^{+}{\pi }^{-}\eta$ reaction

   Hai-Peng Li🇨🇳 · Jia-Xin Lin🇨🇳 · Wei-Hong Liang🇨🇳 · Eulogio Oset🇪🇸

   We analyze the clean cusp, seen in the $\eta \pi$ mass distribution with high precision of the ${\chi }_{c1}\to \eta {\pi }^{+}{\pi }^{-}$ reaction in the BESIII experiment, with the aim of making a precise determination of the scattering length $a$ and effective range $r_0$ of $K^{+}{\bar{K}}^0$. For that, we follow a previous theoretical work that gave a good reproduction of these data using the chiral unitary approach for the meson-meson interaction, and allow some flexibility in the input to carry a better fit to the data. The important task of determining the uncertainties in the scattering parameters is done using the resampling method and an accuracy in $a$ and $r_0$ is obtained better than $20\%$. The effective range is determined for the first time with this analysis.

   hep-phEPJA(2025)·5 citations
9. 09*

   Inclusive and diffractive neutrino-nucleus scattering at high energy

   Anh Dung Le🇫🇮 · Heikki Mäntysaari🇫🇮

   We calculate the energy dependence of inclusive and diffractive neutrino-nucleus deep-inelastic scattering cross sections within the dipole picture, focusing on the ultra-high-energy regime. We predict an up to $\sim 10\%$ nuclear suppression in the inclusive neutrino-Oxygen scattering originating from the non-linear QCD dynamics in the small-$x$ Balitsky-Kovchegov evolution. Diffraction is found to be a small $1\dots 4\%$ contribution to the total cross section across a wide range of neutrino energies relevant for current and near-future experiments. The diffractive cross section is calculated separately for the coherent and incoherent channels that are found to be of equal importance. Additionally, we include the dominant contribution from the $|q\bar{q}g⟩$ Fock state of the $W^{\pm }$ and $Z$ bosons in the high-$Q^2$ limit, along with the lowest-order $|q\bar{q}⟩$ contribution. The $|q\bar{q}g⟩$ contribution is found to be numerically significant, reaching up to 40\% of the diffractive cross section.

   hep-phPRD(2024)·1 citation
10. 10*

    From angular coefficients to quantum observables: a phenomenological appraisal in di-boson systems

    Michele Grossi🇨🇭 · Giovanni Pelliccioli🇩🇪 · Alessandro Vicini🇮🇹

    Motivated by the growing interest in accessing the spin structure of multi-boson processes and in measuring quantum entanglement at high energies, we study polarisation and spin-correlation coefficients in di-boson systems. We show that higher-order corrections of QCD and electroweak type, off-shell modelling, and realistic effects such as fiducial selections and neutrino reconstruction are unavoidable to properly determine such coefficients, and consequently to provide a sound interpretation of observables sensitive to quantum entanglement and Bell-inequality violation. Our findings are based on a detailed phenomenological analysis of boson pairs at the LHC, either in inclusive electroweak production or coming from Higgs-boson decays.

    hep-phhep-exquant-phJHEP(2024)·53 citations
11. 11*

    Lectures on scattering theory in partial-wave amplitudes

    J.A. Oller🇪🇸

    These lectures treat scattering theory from a non-perturbative point of view. The course begins with a review of formal aspects in scattering theory, discussing the in/out states and the $S$ matrix that connects them. Unitarity relations, phase space, and the Lippmann-Schwinger equation for the $T$ matrix are discussed. The calculation of cross sections, the optical theorem and Boltzmann $H$-theorem from unitarity of the $S$ matrix are also explained. Special emphasis is given to expansions in partial-wave amplitudes of two-body scattering amplitudes, both for massive and massless particles, and to unitarity in partial-wave amplitudes. In this way, partial-wave expansions in terms of $\ell SJ$ states, and using helicity states with definite total angular momentum $J$ are discussed. Crossing symmetry is also explained, and connected to crossed channels, analyticity and crossed-channel cuts in partial-wave amplitudes. Different non-perturbative techniques and general parameterizations are developed for partial-wave amplitudes that satisfy unitarity and are consistent with the analyticity properties that they must have. Then, the $N/D$ method and additional solutions generated by adding CDD poles are covered in detail. The change to different non-physical Riemann sheets and the search for resonant poles is discussed as well. A differentiation is made between dynamically generated resonances by the degrees of freedom explicitly accounted for versus pre-existing resonances derived from short-distance dynamics. We exemplify it with the cases of the $\sigma /f_0(500)$ and the $\rho (770)$ resonances in $\pi \pi$ scattering. The reader is also introduced to final-state interactions, Watson's theorem, and general parameterizations to take them into account. It ends with an appendix dedicated to the Sugawara-Kanazawa theorem regarding the number of subtractions in dispersion relations.

    hep-ph5 citations
12. 12*

    Correlative study of flavor anomalies and dark matter in the light of scalar leptoquark

    Manas Kumar Mohapatra🇮🇳 · Shivaramakrishna Singirala🇮🇳 · Dhiren Panda🇮🇳 · Rukmani Mohanta🇮🇳

    We explore $U(1{)}_{L_e-L_{\mu }}$ gauge extension of the Standard Model with particle content enlarged by three neutral fermions, of which the lightest one contributes to dark matter content of the Universe. The scalar sector is enriched with a ${\tilde{R}}_2$ scalar leptoquark doublet to investigate flavor anomalies in $B$-meson sector, an additional inert scalar doublet to realize neutrino mass at one loop and a scalar singlet to spontaneously break the new $U(1)$. We discuss dark matter relic density and direct detection cross section in scalar and gauge portals. New physics contribution for $b\to s$ transition comes from penguin diagrams with $Z^{\prime }$, leptquark and new fermions. We analyze the constraints on the model parameters from the established observables of $B\to K^{(\ast )}{\mu }^{+}{\mu }^{-}$ and $B_s\to \varphi {\mu }^{+}{\mu }^{-}$ decay channels. Utilizing the permissible parameter space consistent with both flavor and dark sectors, we discuss the impact on various observables such as branching ratio, forward-backward asymmetry, longitudinal polarisation asymmetry, and also lepton non-universality of ${\Lambda }_b\to {\Lambda }^{\ast }(1520)(\to pK){\ell }^{+}{\ell }^{-}$ decay channel.

    hep-phPhys.Dark Univ.(2026)·1 citation
13. 13*

    A singlet scalar assisted $N_2$ Leptogenesis and Pseudo-Scalar Dark Matter

    Dilip Kumar Ghosh🇮🇳 · Purusottam Ghosh🇮🇳 · Koustav Mukherjee🇮🇳 · Nimmala Narendra🇮🇳

    We study the Leptogenesis and Dark Matter in the presence of an extra singlet complex scalar field in an extended discrete ${\mathcal{Z}}_3$ symmetry. The vacuum expectation value of the new scalar spontaneously breaks the ${\mathcal{Z}}_3$ symmetry. A remnant CP-like ${\mathcal{Z}}_2$ symmetry stabilizes the imaginary part of the complex scalar field which can act as a pseudo-Goldstone DM. The real part of the complex scalar couples to RHN opens up new decay channels which can lead to a larger CP-violation in generating the lepton asymmetry. Thus the singlet complex scalar plays a crucial role in understanding the Leptogenesis and Dark Matter parameter space. This singlet complex scalar is also responsible for the First-Order Phase Transition (FOPT) which may provide observable stochastic Gravitational wave signatures. We discuss the possible correlations among these three phenomena.

    hep-phEPJC(2025)·3 citations
14. 14*

    Relativistic and Recoil Corrections to Vacuum polarization in muonic systems: Three--photon exchange, gauge invariance and numerical values

    Gregory S. Adkins🇺🇸 · Ulrich D. Jentschura🇺🇸

    For an accurate theoretical description of muonic bound systems, it is crucial to consistently treat relativistic and recoil corrections to vacuum polarization. The one-loop vacuum-polarization effect is by far the dominant quantum electrodynamic (QED) energy correction for bound muons, being of order $\alpha (Z\alpha {)}^2{m}_r$, where $\alpha$ is the fine-structure constant, $Z$ is the nuclear charge number, and $m_r$ is the reduced mass. Gauge invariance of the relativistic and recoil corrections to vacuum polarization of order $\alpha (Z\alpha {)}^4{m}_r$ is investigated with respect to nonretarded and standard, renormalized variants of Coulomb gauge. The invariance is shown after including three-photon exchange diagrams. Our derivation is based on an adapted form of Nonrelativistic Quantum Electrodynamics for bound muon systems (NRQED${}_{\mu }$), which is a version of NRQED where the hard scale is set at the muon mass instead of the electron mass. Updated values for the gauge-independent corrections for one-muon ions with nuclear charge numbers $Z=1,2,6$ are presented.

    hep-phPRA(2024)·5 citations
15. 15*

    Annihilating to the Darker: Thermal Relic Dark Matter with an Ultraweak Portal to the Standard Model

    Wan-Zhe Feng🇨🇳 · Zi-Hui Zhang🇨🇳

    Thermal relic dark matter has been severely constrained in recent years by direct and indirect dark matter searches, as well as multi-messenger probes of dark sectors. At the current level of experimental precision, it has become difficult for many thermal dark matter models to deplete their abundance sufficiently through freeze-out to reproduce the observed relic density. We study the possibility that thermal dark matter couples only ultraweakly to the Standard Model (SM), and therefore remains effectively undetectable in current experiments, while interacting much more strongly with a darker sector that controls its freeze-out history. Hence, the dominant annihilation channels of a thermal relic may proceed primarily into the darker sector rather than into SM particles. We first summarize the general classes of portal interactions that may connect the SM, a hidden sector, and a darker concealed sector, together with the corresponding experimental constraints. We then illustrate the mechanism in two representative realizations. The first is a prototype $U(1{)}_x\times U(1{)}_c$ setup with kinetic and mass mixing between the hidden and concealed gauge sectors. The second is a more motivated $U(1{)}_{B-L}\times U(1{)}_c$ construction, in which the $U(1{)}_{B-L}$ gauge interaction is strongly constrained and the hidden--concealed connection is mediated primarily by a real scalar. In both frameworks, we identify two qualitatively distinct scenarios: assisted depletion and darker conversion. By solving the full set of coupled Boltzmann equations and presenting benchmark models for dark matter masses in the 1--200~GeV range, we show that electroweak scale thermal relic dark matter may remain viable even when its direct portal to the SM is ultraweak, provided that sufficiently strong hidden--concealed interactions govern the cosmological evolution.

    hep-ph2 citations
16. 16*

    Small-$x$ gluon GPD constrained from deeply virtual $J/\psi$ production and gluon PDF through universal-moment parameterization

    Yuxun Guo🇺🇸 · Xiangdong Ji🇺🇸 · M. Gabriel Santiago🇺🇸 · Jinghong Yang🇺🇸 · Hao-Cheng Zhang🇨🇳

    We phenomenologically constrain the small-$x$ and small-$\xi$ gluon generalized parton distributions (GPDs) with the deeply virtual $J/\psi$ production (DV$J/\psi$P) in the framework of GPDs through universal moment parameterization (GUMP). We use a hybrid cross-section formula combining collinear factorization to the next-to-leading order (NLO) accuracy of the strong coupling ${\alpha }_s$, with corrections from non-relativistic QCD to account for the power corrections due to the heavy $J/\psi$ mass. We reach reasonable fit to the measured differential cross-sections of DV$J/\psi$P by H1 at Hadron-Electron Ring Accelerator (HERA) as well as forward gluon PDFs from JAM22 global analysis. We find that both NLO and non-relativistic corrections are significant for heavy vector meson productions. Of course, the gluon GPD we obtain still contain considerable freedom in need of inputs from other constraints, particularly in the distribution-amplitude-like region.

    hep-phnucl-thPRD(2025)·13 citations
17. 17*

    Theory of neutrino fast flavor evolution. Part II. Solutions at the edge of instability

    Damiano F. G. Fiorillo🇩🇪 · Georg G. Raffelt🇩🇪

    In dense neutrino environments, such as provided by core-collapse supernovae or neutron-star mergers, neutrino angular distributions may be unstable to collective flavor conversions, whose outcome remains to be fully understood. These conversions are much faster than hydrodynamical scales, suggesting that self-consistent configurations may never be strongly unstable. With this motivation in mind, we study weakly unstable modes, i.e., those with small growth rates. We show that our newly developed dispersion relation (Paper~I of this series) allows for an expansion in powers of the small growth rate. For weakly unstable distributions, we show that the unstable modes must either move with subluminal phase velocity, or very close to the speed of light. The instability is fed from neutrinos moving resonantly with the waves, allowing us to derive explicit expressions for the growth rate. For axisymmetric distributions, often assumed in the literature, numerical examples show the accuracy of these expressions. We also note that for the often-studied one-dimensional systems one should not forget the axial-symmetry-breaking modes, and we provide explicit expressions for the range of wavenumbers that exhibit instabilities.

    hep-phastro-ph.HEJHEP(2024)·32 citations
18. 18*

    Long-lived Sterile Neutrino Searches at Future Muon Colliders

    Qi Bi🇨🇳 · Jinhui Guo🇨🇳 · Jia Liu🇨🇳 · Yan Luo🇨🇳 · Xiao-Ping Wang🇨🇳

    We explore the potential of studying sterile neutrinos at a future high-energy muon collider, where these particles can generate small active neutrino masses via the seesaw mechanism and exhibit long-lived particle signatures. A Dirac sterile neutrino model with ${\mathrm{U}(1)}_{L_{\mu }-L_{\tau }}$ symmetry is introduced, where the heavy right-handed neutrino ($N_R$) produces tiny active neutrino masses, and the light left-handed neutrino ($N_L$) naturally behaves as a long-lived particle. The ${\mathrm{U}(1)}_{L_{\mu }-L_{\tau }}$ gauge symmetry also enhances sterile neutrino pair production at a future high-energy muon collider. Using the displaced vertex method, the muon collider can search for heavy sterile neutrino, especially for $m_L>m_W$. We find that a muon collider with $\sqrt{s}=3(10)$ TeV and luminosity $L=1(10)$ ab${}^{-1}$ can probe $N_L$ masses of $m_L\in [100,1500(5000)]$ GeV and mixing angles ${\theta }_{\nu L}\in [10^{-13},10^{-6}]$.

    hep-phPRD(2025)·11 citations
19. 19*

    Investigation of the internal structure of the deuteron against the background of two-photon exchange effects in elastic electron-deuteron scattering

    Ya. D. Krivenko-Emetov🇺🇦 · O. S. Shevchuk🇺🇦

    The aim of this work is to investigate the simultaneous influence of two-photon effects in quantum electrodynamics (QED) and logarithmic corrections in quantum chromodynamics (QCD) on certain observable experimental quantities (structure factors $A$ and $B$) in elastic electron-deuteron scattering. Analyzing these effects broadens our understanding of particle physics, particularly the manifestations of quark-gluon degrees of freedom in the deuteron. Keywords: elastic electron-deuteron scattering, structure of the deuteron, deuteron structure functions, QCD, QED, quark, gluon, two-photon exchange effects, theory-data comparison.

    hep-phnucl-thNucl.Phys.Atom.Energy(2024)·3 citations
20. 20*

    ChatQCD: Let Large Language Models Explore QCD

    Antonin Sulc🇩🇪 · Patrick L.S. Connor🇩🇪

    Quantum chromodynamics (QCD) has yielded a vast literature spanning distinct phenomena. We construct a corpus of papers and build a generative model. This model holds promise for accelerating the capability of scientists to consolidate their knowledge of QCD by the ability to generate and validate scientific works in the landscape of works related to QCD and similar problems in HEP. Furthermore, we discuss challenges and future directions of using large language models to integrate our scientific knowledge about QCD through the automated generation of explanatory scientific texts.

    hep-phphysics.ed-phPoS(2025)·1 citation
21. 21*

    The Unknowns of the Diffuse Supernova Neutrino Background Hinder New Physics Searches

    Miller MacDonald🇩🇰 · Pablo Martínez-Miravé🇩🇰 · Irene Tamborra🇩🇰

    Neutrinos traveling over cosmic distances are ideal probes of new physics. We leverage on the approaching detection of the diffuse supernova neutrino background (DSNB) to explore whether, if the DSNB showed departures from theoretical predictions, we could attribute such modifications to new physics unequivocally. In order to do so, we focus on visible neutrino decay. Many of the signatures from neutrino decay are degenerate with astrophysical unknowns entering the DSNB modeling. Next generation neutrino observatories, such as Hyper-Kamiokande, JUNO, as well as DUNE, will set stringent limits on a neutrino lifetime over mass ratio $\tau /m\sim 10^9$-$10^{10}$ s eV${}^{-1}$ at $90\%$ C.L., if astrophysical uncertainties and detector backgrounds were to be fully under control. However, if the lightest neutrino is almost massless and the neutrino mass ordering is normal, constraining visible decay will not be realistically possible in the coming few decades. We also assess the challenges of distinguishing among different new physics scenarios (such as visible decay, invisible decay, and quasi-Dirac neutrinos), all leading up to similar signatures in the DSNB. This work shows that the DSNB potential for probing new physics strongly depends on an improved understanding of the experimental backgrounds at next generation neutrino observatories as well as progress in the DSNB modeling.

    ↳ astro-ph.HEhep-phJCAP(2025)·15 citations
22. 22*

    $p\Omega$ femtoscopy using baryon-baryon effective potentials

    Marc Piquer i Méndez🇪🇸 · Assumpta Parreño🇪🇸 · Juan Torres-Rincon🇪🇸

    We have generated an updated version of the $p\Omega$ potential for low-energy interactions based on an effective field theory approach at leading order. This potential, together with other potentials based either on different parametrizations or lattice QCD calculations, have been used to solve the Schrödinger equation numerically, obtaining the scattering wave functions for different values of the relative momentum. Using these wave functions, we have computed the $p\Omega$ femtoscopic correlation functions, comparing the results with those published by the ALICE collaboration.

    ↳ nucl-thhep-phPoS(2025)·3 citations
23. 23*

    Parton Distribution Functions in the Schwinger Model with Tensor Networks

    Mari Carmen Bañuls🇩🇪 · Krzysztof Cichy🇵🇱 · C.-J. David Lin🇹🇼 · Manuel Schneider🇹🇼

    Parton distribution functions (PDFs) describe universal properties of bound states and allow us to calculate scattering amplitudes in processes with large momentum transfer. Calculating PDFs involves the evaluation of matrix elements with a Wilson line in a light-cone direction. In contrast to Monte Carlo methods in Euclidean spacetime, these matrix elements can be directly calculated in Minkowski-space using the Hamiltonian formalism. The necessary spatial- and time-evolution can be efficiently applied using established tensor network methods. We present PDFs in the Schwinger model calculated with matrix product states.

    ↳ hep-lathep-phphysics.comp-phPoS(2025)·14 citations
24. 24*

    Matching current observational constraints with nonminimally coupled dark energy

    William J. Wolf🇬🇧 · Pedro G. Ferreira🇬🇧 · Carlos García-García🇬🇧

    We show that a Universe with a nonminimally coupled scalar field can fit current measurements of the expansion rate of the Universe better than the standard $\Lambda$-Cold Dark Matter ($\Lambda$CDM) model or other minimally coupled dark energy models. In particular, the nonminimal coupling in this model allows for the dark energy model to exhibit stable phantom crossing behavior, which seems to be suggested by the constraints on the dark energy equation of state coming from the most recent data. While we find a clear improvement in the goodness of fit for this dark energy model with respect to others that have been considered in the recent literature, using information theoretic criteria, we show that the evidence for it is still inconclusive.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2025)·145 citations
25. 25*

    Finite- and infinite-volume study of $DD\pi$ scattering

    Sebastian M. Dawid🇺🇸 · Fernando Romero-López🇺🇸 · Stephen R. Sharpe🇺🇸

    We develop a comprehensive framework for extracting the pole position and properties of the doubly-charmed tetraquark $T_{\mathrm{cc}}^{+}(3875)$ from lattice QCD data using the relativistic three-particle formalism. This approach incorporates the effect of the one-pion exchange diagram in $DD\pi$ and $D{D}^{\ast }$ scattering, making it applicable at energies coinciding with the left-hand cut in the partial-wave projected $D{D}^{\ast }$ amplitude. We present an example application of this framework to existing lattice QCD data at $m_{\pi }=280$ MeV. We solve the integral equations describing the $DD\pi$ reaction, use LSZ reduction to determine the corresponding $D{D}^{\ast }$ amplitude, and find the values of the infinite-volume two- and three-body $K$ matrices that lead to agreement with lattice $D{D}^{\ast }$ phase shifts within their uncertainties. Using these $K$ matrices in the three-particle quantization condition, we describe the finite-volume $D{D}^{\ast }$ spectrum and find good agreement with the lattice QCD energies. Our results suggest that, at this pion mass, the tetraquark appears as a pair of subthreshold complex poles whose precise location strongly depends on the value of the $DD\pi$ three-particle $K$ matrix.

    ↳ hep-lathep-phnucl-thJHEP(2025)·39 citations
26. 26*

    Dynamical Dark Energy Beyond Planck? Constraints from multiple CMB probes, DESI BAO and Type-Ia Supernovae

    William Giarè🇬🇧

    The latest Baryon Acoustic Oscillation (BAO) measurements from the Dark Energy Spectroscopic Instrument (DESI) collaboration, when combined with Planck satellite Cosmic Microwave Background (CMB) data and Type Ia Supernovae, suggest a preference for Dynamical Dark Energy (DDE) at a significance level ranging from $2.8\sigma$ to $4.2\sigma$. In this work, I test whether, and to what extent, this preference is supported by CMB experiments other than Planck. I analyze the latest Atacama Cosmology Telescope (ACT) and South Pole Telescope (SPT) temperature, polarization, and lensing spectra at small scales, eventually combining them with Planck or WMAP 9-year observations at large angular scales. My analysis shows that ACT and WMAP data, when combined with DESI BAO and Pantheon-plus Supernovae, yield independent constraints with a precision comparable to Planck. Notably, in this case, the cosmological constant value is recovered within two standard deviations. A preference for DDE reappears when Pantheon-plus is replaced with distance moduli measurements from the Dark Energy Survey Supernova program (DESy5). However, it remains less pronounced compared to the Planck-based results. When considering SPT data, no clear preference for DDE is found in combinations involving Pantheon-plus Supernovae, and the preference is significantly weaker in combinations involving DESy5. Overall, CMB experiments other than Planck generally weaken the evidence for DDE. I argue that the subsets of Planck data that strengthen the shift toward DDE are the temperature and E-mode polarization anisotropy measurements at large angular scales $\ell \lesssim 30$.

    ↳ astro-ph.COhep-phPRD(2025)·134 citations
27. 27*

    The effect of causality constraints on Bayesian analyses of heavy-ion collisions

    Thiago S. Domingues🇧🇷 · Renata Krupczak🇩🇪 · Jorge Noronha🇺🇸 · Tiago Nunes da Silva🇧🇷 · Jean-François Paquet🇺🇸 · Matthew Luzum🇧🇷

    There have long been questions about the limits to the validity of relativistic fluid dynamics, and whether it is being used outside its regime of validity in modern simulations of relativistic heavy-ion collisions. An important new tool for answering this question is a causality analysis in the nonlinear regime -- if the solutions of the evolution equations do not respect relativistic causality, they are not a faithful representation of the underlying relativistic theory (in this case, quantum chromodynamics). Using this non-linear criterion, it has recently been shown that hydrodynamics is indeed being used outside its regime of validity in simulations, at least sometimes. Here we explore the phenomenological implications, particularly the quantitative effects of demanding limits on acausality in modern Bayesian parameter estimation. We find that, while typically only a small fraction of the system's energy is initially in an acausal regime, placing strict limits on the allowed energy fraction significantly changes the preferred properties of the initial condition, which in turn alters the extracted medium properties such as bulk viscosity, where large values are no longer favored. These findings highlight the importance of developing better theoretical descriptions of the early-time, out-of-equilibrium dynamics of relativistic heavy-ion collisions.

    ↳ nucl-thhep-phPRC(2024)·15 citations
28. 28*

    Neutron Star with Dark Matter Admixture: A Candidate for Bridging the Mass Gap

    M. Vikiaris🇬🇷 · V. Petousis🇨🇿 · M. Veselsky🇨🇿 · Ch.C. Moustakidis🇬🇷

    Neutron stars, white dwarfs and black holes are the after death remnants of massive stars. However, according to the most recent observations, the neutron stars maximum mass is between $2.0-2.5M_{\odot }$ while black holes of less than 5 $M_{\odot }$ has not yet been observed. The region between the most massive neutron star and the least massive black hole is called the mass-gap. If indeed its existence is confirmed by future observations, that indicates a gap in our understanding which seeks for explanation. In addition, the existence of compact objects within the mass-gap should also be supported with the help of possible new theoretical scenarios. In this study, we propose a possible explanation for the existence of compact objects within the mass-gap region. Specifically, we propose that the mass-gap region could be bridged by the existence of a hybrid compact object, composed of hadronic and self interacting and non-annihilating fermionic dark matter, considering that the interaction between these two fluids it is only gravitational. Fundamental questions about how these objects form and how they can be detected are also addressed.

    ↳ astro-ph.HEastro-ph.SRhep-phnucl-thInt.J.Mod.Phys.D(2025)·8 citations
29. 29*

    Polarized and unpolarized gluon PDFs: generative machine learning applications for lattice QCD matrix elements at short distance and large momentum

    Talal Ahmed Chowdhury🇧🇩 · Taku Izubuchi🇺🇸 · Methun Kamruzzaman🇺🇸 · Nikhil Karthik🇺🇸 · Tanjib Khan🇧🇩 · Tianbo Liu🇨🇳 · Arpon Paul🇺🇸 · Jakob Schoenleber🇺🇸 · Raza Sabbir Sufian🇺🇸

    Lattice quantum chromodynamics (QCD) calculations share a defining challenge by requiring a small finite range of spatial separation $z$ between quark/gluon bilinears for controllable power corrections in the perturbative QCD factorization, and a large hadron boost $p_z$ for a successful determination of collinear parton distribution functions (PDFs). However, these two requirements make the determination of PDFs from lattice data very challenging. We present the application of generative machine learning algorithms to estimate the polarized and unpolarized gluon correlation functions utilizing short-distance data and extending the correlation up to $z{p}_z\lesssim 14$, surpassing the current capabilities of lattice QCD calculations. We train physics-informed machine learning algorithms to learn from the short-distance correlation at $z\lesssim 0.36$ fm and take the limit, $p_z\to \infty$, thereby minimizing possible contamination from the higher-twist effects for a successful reconstruction of the polarized gluon PDF. We also expose the bias and problems with underestimating uncertainties associated with the use of model-dependent and overly constrained functional forms, such as $x^{\alpha }(1-x{)}^{\beta }$ and its variants to extract PDFs from the lattice data. We propose the use of generative machine learning algorithms to mitigate these issues and present our determination of the polarized and unpolarized gluon PDFs in the nucleon.

    ↳ hep-lathep-phnucl-thPRD(2025)·17 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.