Thu·Aug 8, 2024Thursday·August 8, 2024

1. 01*

   Euclidean Effective Theory for Partons in the Spirit of Steven Weinberg

   Xiangdong Ji🇺🇸

   The standard formulation of parton physics involves light-cone correlations of quark and gluon fields in a hadron, which leads to a widespread impression that it can only be studied through real-time Hamiltonian dynamics or light-front quantization, which are challenged by non-perturbative computations with a pertinent regulator for light-cone/rapidity divergences (or zero modes). As such, standard lattice QCD studies have been limited to indirect parton observables such as first few moments and short-distance correlations, which do not provide the $x$-distributions without solving the model-dependent inverse problem. Here I describe an alternative formulation of partons in terms of equal-time (or Euclidean) correlators, which allows to compute precision-controlled $x$-distribution through lattice QCD simulations. This approach is in accord with Weinberg's pioneering idea of effective field theory as well as Wilson's renormalization group, in which the large hadron momentum serves as a natural cut-off for light-cone/rapidity divergences and can ultimately be eliminated through a method like the ``perfect action'' program in lattice QCD.

   hep-phhep-lathep-thnucl-thNPB(2024)·19 citations
2. 02*

   Uniting Low-energy Semileptonic and Hadronic Anomalies within SMEFT

   Alakabha Datta🇺🇸 · Jacky Kumar🇺🇸 · Suman Kumbhakar🇨🇦 · David London🇨🇦

   Two categories of four-fermion SMEFT operators are semileptonic (two quarks and two leptons) and hadronic (four quarks). At tree level, an operator of a given category contributes only to processes of the same category. However, when the SMEFT Hamiltonian is evolved down from the new-physics scale to low energies using the renormalization-group equations (RGEs), due to operator mixing this same SMEFT operator can generate operators of the other category at one loop. Thus, to search for a SMEFT explanation of a low-energy anomaly, or combination of anomalies, one must: (i) identify the candidate semileptonic and hadronic SMEFT operators, (ii) run them down to low energy with the RGEs, (iii) generate the required low-energy operators with the correct Wilson coefficients, and (iv) check that all other constraints are satisfied. In this paper, we illustrate this method by finding all SMEFT operators that, by themselves, provide a combined explanation of the (semileptonic) $\bar{b}\to \bar{s}{\ell }^{+}{\ell }^{-}$ anomalies and the (hadronic) $B\to K\pi$ puzzle.

   hep-phhep-exJHEP(2024)·10 citations
3. 03*

   Heavy Neutral Lepton searches at an ICARUS-like detector using NuMI beam

   Animesh Chatterjee🇨🇭 · Josu Hernandez-Garcia🇪🇸 · Albert De Roeck🇨🇭

   The discovery of non-zero neutrino masses points to the likely existence of multiple SM neutral fermions. When such states are heavy enough that they cannot be produced in oscillations, they are referred to as Heavy Neutral Leptons (HNLs). In minimal models, the HNL production and decay are controlled by SM interactions and the mixing between HNLs and the active neutrino and typically result in relatively long lifetimes if the masses are in the MeV-GeV range. We have studied the physics case and technical feasibility for a dedicated HNL search using the NuMI beam at an ICARUS-like detector. Our analysis conclusively demonstrates that the constraints on the mixing of the HNL as a function of its mass for an ICARUS-like detector with NuMI beam are highly competitive with the limits obtained from present experiments.

   hep-ph4 citations
4. 04*

   T-odd Wigner Distributions in boost-invariant longitudinal position space and Spin-momentum correlation in proton

   Tanmay Maji🇮🇳

   The boost invariant longitudinal position space variable $\sigma$, which is the Fourier conjugate to skewness $\xi$, unravels the longitudinal impact parameter information in a proton. Here, we investigate the skewness sensitivity of T-odd leading twist GTMDs within the Dokshitzer Gribov Lipatov Altarelli Parisi (DGLAP) region, considering a momentum transfer to longitudinal as well as transverse direction. The $\sigma$-space distributions of the T-odd sector show oscillatory patterns that are sensitive to the square of the total momentum transfer $-t$, which is analogous to the diffraction scattering of waves in Optics. An additional effect on the diffraction pattern is reported, caused by interference between transverse momentum transfer $\text{bfd}$ to the transverse momentum $\text{bfp}$ of quarks. We also present the correlation of proton spin to the transverse momentum of constituents through Sivers and Boer-Mulders Wigner Distributions in boost invariant longitudinal position space.

   hep-phNPA(2026)·0 citations
5. 05*

   Probing radiative electroweak symmetry breaking with colliders and gravitational waves

   Wei Liu🇨🇳 · Ke-Pan Xie🇨🇳

   Radiative symmetry breaking provides an appealing explanation for electroweak symmetry breaking and addresses the hierarchy problem. We present a comprehensive phenomenological study of this scenario, focusing on its key feature: the logarithmic-shaped potential. This potential gives rise to a relatively light scalar boson that mixes with the Higgs boson and leads to first-order phase transitions (FOPTs) in the early Universe. Our detailed analysis includes providing exact and analytical solutions for the vacuum structure and scalar interactions, classifying four patterns of cosmic thermal history, and calculating the supercooled FOPT dynamics and GWs. By combining future collider and gravitational wave experiments, we can probe the conformal symmetry breaking scales up to $10^5-10^8$ GeV.

   hep-phastro-ph.COPRD(2024)·16 citations
6. 06*

   Exploring the Singlino-dominated Thermal Neutralino Dark Matter in the $Z_3$ invariant NMSSM

   Amit Adhikary🇫🇷 · Rahool Kumar Barman🇯🇵 · Biplob Bhattacherjee🇮🇳 · Amandip De🇮🇳 · Rohini M. Godbole🇮🇳

   We examine the parameter space of the Next to Minimal Supersymmetric Standard Model (NMSSM) with Singlino-dominated neutralino ${\tilde{\chi }}_1^0$ as the lightest supersymmetric particle (LSP). Our study focuses on identifying the regions within this parameter space that produce a thermal relic abundance of ${\tilde{\chi }}_1^0$ smaller than the observed cold dark matter relic density while remaining consistent with constraints from LEP measurements, low-energy experiments, Higgs measurements, LHC data, and dark matter direct detection experiments. We identify the dominant annihilation modes of the LSP neutralino across varying LSP mass ranges $\sim \mathcal{O}(1)-\mathcal{O}(10^3)$GeV. Furthermore, we conduct a benchmark study to assess the production rates of triple-boson final states emerging from direct electroweakino pair production at the LHC. Drawing insights from these findings, we perform a detailed collider analysis to explore the future potential of probing the triple-boson final states involving a light Higgs boson at the high-luminosity LHC (HL-LHC).

   hep-phhep-ex2 citations
7. 07*

   A 95 GeV Higgs boson and spontaneous CP-violation at the finite temperature

   Jing Gao · Jinghong Ma · Lei Wang · Haotian Xu

   The ATLAS and CMS collaborations reported a diphoton excess in the invariant mass distribution around the 95.4 GeV with a local significance of $3.1\sigma$. Moreover, there is another $2.3\sigma$ local excess in the $b\bar{b}$ final state at LEP in the same mass region. A plausible solution is that the Higgs sector is extended to include an additional Higgs boson with a mass of $95.4$ GeV. We study a complex singlet scalar extension of the two-Higgs-doublet model in which the 95.4 GeV Higgs is from the mixing of three CP-even Higgs fields. In addition, the extended Higgs potential can achieve spontaneous CP-violation at the finite temperature and restore CP symmetry at the present temperature of the Universe. We find that the model can simultaneously explain the baryon asymmetry of the Universe, the diphoton and $b\bar{b}$ excesses around the 95.4 GeV while satisfying various relevant constraints including the experiments of collider and electric dipole moment.

   hep-phPRD(2024)·15 citations
8. 08*

   Thermodynamics of Rotating Lifshitz Dilaton Black Brane in Quartic Quasitopological gravity

   M. Ghanaatian🇮🇷 · F. Esmaeili🇮🇷 · A. Bazrafshan🇮🇷 · Gh. Forozani🇮🇷

   In this paper, we obtain the rotating Lifshitz dilaton black brane solutions in the presence of the quartic quasitopological gravity and then probe the related thermodynamics. At first, we obtain the field equations form which a total constant along the radial coordinate $r$ is deduced. Since we cannot solve the solutions exactly, so we investigate their asymptotic behaviors at the horizon and at the infinity. We attain the conserved and thermodynamic quantities such as temperature, angular velocity, entropy, the energy and the angular momentum densities of the rotating quartic quasitopological Lifshitz dilaton black brane. By evaluating the total constant at the horizon and the infinity, we can make a relation between the thermodynamic quantities and so get to a Smarr-type formula. We demonstrate that the thermodynamic quantities of this rotating black brane obey the first law of the thermodynamics. We also study the thermal stability of the rotating quartic quasitopological Lifshitz dilaton black brane and it is not thermally stable.

   hep-phgr-qcGen.Rel.Grav.(2026)·0 citations
9. 09*

   Regge trajectories for the triply heavy triquarks

   He Song🇨🇳 · Jia-Qi Xie🇨🇳 · Jiao-Kai Chen🇨🇳

   We attempt to apply the Regge trajectory approach to the triply heavy triquarks $((Q{Q}^{\prime }){\bar{Q}}^{\prime \prime })$ $(Q,Q^{\prime },Q^{\prime \prime }=b,c)$. We present the triquark Regge trajectory relations, and then employ them to crudely estimate the spectra of the triquarks $((cc)\bar{c})$, $((cc)\bar{b})$, $((bc)\bar{c})$, $((bc)\bar{b})$, $((bb)\bar{c})$, and $((bb)\bar{b})$. The $\lambda$-trajectories and the $\rho$-trajectories are discussed. The triquark Regge trajectory becomes a new and very simple approach for estimating the spectra of triquarks. Moreover, the spin-averaged masses of the ground states of pentaquarks $(\bar{c}(cc))(cc)$, $(\bar{b}(cc))(cc)$ and $(\bar{c}(bb))(cc)$ are estimated, which are consistent with other theoretical predictions.

   hep-phEPJC(2025)·10 citations
10. 10*

    Deep Inelastic Scattering in the Capture of Dark Matter by Neutron Stars

    Liangliang Su🇨🇳 · Lei Wu🇨🇳 · Meiwen Yang🇨🇳

    Due to the dense environment, neutron stars (NSs) can serve as an ideal laboratory for studying the interactions between dark matter (DM) and ordinary matter. In the process of DM capture, deep inelastic scattering may dominate over elastic scattering, especially for the DM with a large momentum transfer. In this work, we calculate DM-nucleon deep inelastic scattering via a vector mediator and estimate its contribution to the capture rate. Using the surface temperature of the NSs, we derive the exclusion limits for the DM-nucleon scattering cross section in the mass range, $1\mathrm{GeV}<m_{\chi }<10^5\mathrm{GeV}$. We find the bounds for DM with the mass $\gtrsim$ 1 GeV can be changed several times after including the deep inelastic scattering contribution.

    hep-phastro-ph.COPRD(2024)·7 citations
11. 11*

    Late-time asymptotic solutions, attractor, and focusing behavior of spin hydrodynamics

    Dong-Lin Wang🇨🇳 · Li Yan🇨🇳 · Shi Pu🇨🇳

    We have investigated the late-time asymptotic solutions, attractor, and focusing behavior of minimal causal spin hydrodynamics in Bjorken expansion. Using the method of dominant balance, we derive the late-time asymptotic solutions of the evolution equation for spin density and identify the specific conditions necessary for the spin density to exhibit a power-law decay. We then analyze both the late-time and early-time attractors for the decay rate of spin density. Additionally, we report the focusing behavior in spin hydrodynamics, which has not been found in conventional relativistic hydrodynamics in Bjorken expansion. Our findings suggest that spin density can be treated as a conventional hydrodynamic variable at late times under certain conditions.

    hep-phhep-thnucl-thPRD(2025)·9 citations
12. 12*

    Neural Network Modeling of Heavy-Quark Potential from Holography

    Ou-Yang Luo🇨🇳 · Xun Chen🇨🇳 · Fu-Peng Li🇨🇳 · Xiao-Hua Li🇨🇳 · Kai Zhou🇨🇳

    Using Multi-Layer Perceptrons (MLP) and Kolmogorov-Arnold Networks (KAN), we construct a holographic model based on lattice QCD data for the heavy-quark potential in the 2+1 system. The deformation factor $w(r)$ in the metric is obtained using the two types of neural network. First, we numerically obtain $w(r)$ using MLP, accurately reproducing the QCD results of the lattice, and calculate the heavy quark potential at finite temperature and the chemical potential. Subsequently, we employ KAN within the Andreev-Zakharov model for validation purpose, which can analytically reconstruct $w(r)$, matching the Andreev-Zakharov model exactly and confirming the validity of MLP. Finally, we construct an analytical holographic model using KAN and study the heavy-quark potential at finite temperature and chemical potential using the KAN-based holographic model. This work demonstrates the potential of KAN to derive analytical expressions for high-energy physics applications.

    hep-phEPJC(2025)·23 citations
13. 13*

    B Anomalies in Two Higgs Doublet Model with Flavor Symmetry

    Qiaoyi Wen🇨🇳 · Fanrong Xu🇨🇳

    The long-standing flavor anomalies in $b\to s{\ell }^{+}{\ell }^{-}$ and $b\to c\ell \nu$ persist. In this work, we explore a specific flavor-gauged two-Higgs doublet model (FG2HDM) extended by a scalar singlet, with an imposed $U(1)$ flavor symmetry. Compared to the Standard Model (SM), four additional scalars and one neutral gauge boson $Z^{\prime }$ are added to the particle spectrum. The special Yukawa coupling matrices, due to the $U(1)$ symmetry, lead to flavor-changing neutral Higgs (FCNH) interactions uniquely occurring in the down-type quark sector, while the new gauge boson $Z^{\prime }$ induces flavor-changing neutral current (FCNC) interactions in the down-type quark sector as well. The two distinct types of anomalies can be accommodated simultaneously in such a model. Incorporating scalar and vector contributions to $b\to s{\ell }^{+}{\ell }^{-}$ and $B_s^0$-${\bar{B}}_s^0$ mixing, along with charged Higgs contributions to $b\to c\ell \nu$, we investigate the parameter space in FG2HDM and find substantial room in the solution space. Specifically, in the SM-like model setup, the data suggests that $m_{Z^{\prime }}<450\text{GeV}$, $\tan \beta <28$, and $g^{\prime }/m_{Z^{\prime }}>3.5\times 10^{-4}{\text{GeV}}^{-1}$, while there are fewer constraints on heavy scalars, which can be further tested by a combination of other observables.

    hep-ph0 citations
14. 14*

    Explaining Snowball-in-hell Phenomena in Heavy-ion Collisions Using a Novel Thermodynamic Variable

    Eric Braaten🇺🇸 · Kevin Ingles🇺🇸 · Justin Pickett🇺🇸

    A loosely bound hadronic molecule produced by a relativistic heavy-ion collision has been described as a ``snowball in hell'' since it emerges from a hadron resonance gas whose temperature is orders of magnitude larger than the binding energy of the molecule. This remarkable phenomenon can be explained in terms of a novel thermodynamic variable called the ``contact'' that is conjugate to the binding momentum of the molecule. The production rate of the molecule can be expressed in terms of the contact density at the kinetic freezeout of the hadron resonance gas. It approaches a nonzero limit as the binding energy goes to 0.

    hep-phnucl-thPRL(2025)·6 citations
15. 15*

    Loosely Bound Composite Dark Matter

    Javier F. Acevedo🇺🇸 · Yilda Boukhtouchen🇨🇦 · Joseph Bramante🇨🇦 · Chris Cappiello🇨🇦 · Gopolang Mohlabeng🇺🇸 · Narayani Tyagi🇨🇦

    We investigate loosely bound composite states made of dark matter, where the binding energy for constituent particles is less than the constituent mass. We focus on models of nuclear and molecular dark matter, where constituents are separated by length scales larger than the inverse constituent mass, just like nuclei and atoms in the Standard Model. The cosmology, structure, and interactions at underground experiments are described. We find that loosely bound composites can have a very large cross section for scattering with nuclei that scales with nucleon number like $\sim A^4$. For some couplings, these composites produce extremely soft ($\ll$ keV) individual atomic recoils while depositing a large amount of total recoil energy ($\gg$ keV) in a single passage through a detector, implying an interesting new class of signatures for low threshold direct detection.

    hep-phhep-exJCAP(2025)·13 citations
16. 16*

    Three-Loop OPE Wilson Coefficients of Dimension-Four Operators for (Axial-)Vector and (Pseudo-)Scalar Current Correlators

    Robin Brüser🇩🇪 · André H. Hoang🇦🇹 · Maximilian Stahlhofen🇩🇪

    We calculate the three-loop Wilson coefficients of all physically relevant dimension-four operators, i.e. $G_{\mu \nu }^a{G}^{a,\mu \nu }$, $m_i{\bar{q}}_j{q}_j$ and $m_i{m}_j{m}_k^2$, in the short-distance expansion of the time-ordered product of a pair of gauge-singlet vector, axial-vector, scalar and pseudo-scalar currents. The results are given for a general non-Abelian gauge theory with arbitrary (compact semi-simple) gauge group and $n_f$ light fermion flavors (quarks) in a common arbitrary representation of the gauge group, which includes QCD as a special case. In particular, we allow for arbitrary flavor contents of each of the currents. For the axial-vector current the included contributions from so-called singlet diagrams are consistent with the one-loop axial anomaly.

    hep-phhep-thJHEP(2024)·4 citations
17. 17*

    New Physics at Tera-$Z$: Precision Renormalised

    Lukas Allwicher🇨🇭 · Matthew McCullough🇨🇭 · Sophie Renner🇬🇧

    We study the power of a Tera-$Z$ run at FCC-ee for indirectly detecting or constraining heavy new physics. Our main finding is that nearly every new particle which matches at tree level to dimension-six operators of the Standard Model Effective Field Theory (SMEFT) affects electroweak precision observables (EWPOs) at either tree level or via one loop renormalisation group (RG) running. This is true almost regardless of the structure of couplings to the Standard Model; just a handful of exceptions are identified which can produce zeroes in the EWPO RG equations. Under simple flavour assumptions, we perform fits of each state to projected FCC-ee $Z$ pole measurements, showing that all scenarios can be tested at the TeV scale or better, with many projected exclusions reaching tens of TeV. Tera-$Z$ is argued to provide an almost inescapable probe of heavy new physics.

    hep-phJHEP(2025)·35 citations
18. 18*

    Transverse force distributions in the proton from lattice QCD

    J. A. Crawford🇦🇺 · K. U. Can🇦🇺 · R. Horsley🇬🇧 · P. E. L. Rakow🇬🇧 · G. Schierholz🇩🇪 · H. Stüben🇩🇪 · R. D. Young🇦🇺 · J. M. Zanotti🇦🇺

    Single-spin asymmetries observed in polarised deep-inelastic scattering are important probes of hadron structure. The Sivers asymmetry has been the focus of much attention in QCD phenomenology and is yet to be understood at the quark level. In this Letter, we present a lattice QCD calculation of the spatial distribution of a colour-Lorentz force acting on the struck quark in a proton. We determine a spin-independent confining force, as well as spin-dependent force distributions with local forces on the order of 3 GeV/fm. These distributions offer a complementary picture of the Sivers asymmetry in transversely polarised deep-inelastic scattering.

    ↳ hep-lathep-phnucl-thPRL(2025)·16 citations
19. 19*

    The massless S-matrix of integrable $\sigma$-models

    George Georgiou🇬🇷

    In contradistinction to the case of massive excitations, the connection between integrability and the tree-level massless scattering matrix of integrable $\sigma$-models is lost. Namely, in well-known 2-d integrable models the tree-level massless S-matrix exhibits particle production and fails to factorise. This is conjectured to happen due to IR ambiguities in the massless tree-level amplitudes. We present a definition of the massless S-matrix which has all the nice properties of integrable theories, there is no particle production and the S-matrix factorises. As an example, we present in detail the case of the $SU(2)$ principal chiral model (PCM).

    ↳ hep-thhep-phnlin.SIJHEP(2025)·3 citations
20. 20*

    Infrared Sensitivity of Cosmological Probes In The Presence of Axion Field Fluctuations

    Matteo Magi🇨🇭 · Robert Brandenberger🇨🇦 · Jaiyul Yoo (University of Zurich and McGill University)🇨🇭

    We study the effects of long wavelength entropy fluctuations on cosmological probes such as galaxy clustering, luminosity distance, and CMB temperature anisotropies. Specifically, we consider fluctuations of a massless spectator scalar field set up in the early universe, which later acquires mass during the radiation-dominated era. We find that there are non-vanishing effects on observables, and the amplitude of these effects peaks for observables set up at the time of equal matter and radiation, and decreases as ${\eta }^{-2}$ where $\eta$ is the conformal time. Hence, the back-reaction effects are important for CMB anisotropies, but their impact on late-time observables is suppressed. In particular, the back-reaction effects are unable to explain the Hubble tension while they might alleviate the cosmic dipole tension. In contrast to a lot of the previous work on back-reaction, we work in position rather than momentum space.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2024)·0 citations
21. 21*

    Feasibility of dark matter admixed neutron star based on recent observational constraints

    Prashant Thakur🇮🇳 · Tuhin Malik🇵🇹 · Arpan Das🇮🇳 · T. K. Jha🇮🇳 · B. K. Sharma🇮🇳 · Constança Providência🇵🇹

    The equation of state (EOS) for neutron stars is modeled using the Relativistic Mean Field (RMF) approach with a mesonic nonlinear (NL) interaction, a modified sigma cut potential (NL-$\sigma$ cut), and the influences of dark matter in the NL (NL DM). Using a Bayesian analysis framework, we evaluate the plausibility and impact of each scenario. Experimental constraints on the general properties of finite nuclei and heavy ion collisions, along with astrophysical observational data on neutron star radii and tidal deformation, have been taken into account. It was shown that all models, including the PREX-II data, were less favored, indicating that this experimental data seemed to be in tension with the other constraints included in the inference procedure, and were incompatible with chiral effective field theoretical calculations of pure neutron matter. Considering the models with no PREX-II constraints, we find the model NL-$\sigma$ cut with the largest Bayes evidence, indicating that the constraints considered favor the stiffening of the EOS at large densities. Conversely, the neutron star with a dark matter component is the least favorable case in light of recent observational constraints, among different scenarios considered here. The $f$ and $p$ modes were calculated within the Cowling approximation, and it can be seen that $f$ modes are sensitive to the EOS. An analysis of the slopes of the mass-radius curves and $f$-mode mass curves has indicated that these quantities may help distinguish the different scenarios.We also analyzed the impact of new PSR J0437-4715 measurements on neutron star mass-radius estimates, noting a $\sim$ 0.2 km reduction in the 90\% CI upper boundary across all models and a significant Bayes evidence decrease, indicating potential conflicts with previous data or the necessity for more adaptable models.

    ↳ nucl-thastro-ph.HEgr-qchep-phAstron.Astrophys.(2025)·25 citations
22. 22*

    4D de Sitter from String Theory via 6D Supergravity

    C.P. Burgess🇨🇦 · F. Muia🇬🇧 · F. Quevedo🇬🇧

    We obtain de Sitter (dS) solutions from controlled string-theory constructions. We review how minimal gauged chiral 6D supergravity evades standard dS no-go theorems by having a positive scalar potential and describe the known 4D classical dS, AdS and Minkowski solutions. Grimm and collaborators recently found a related 6D supergravity by direct F-theory Calabi-Yau flux compactifications and we construct classical 4D maximally symmetric solutions for this 6D supergravity. These provide explicit solutions of the higher-dimensional field equations corresponding to dS, AdS and flat spacetimes in 4D, allowing interesting hierarchies of scales. We show how the singularities of these solutions are consistent with the back-reaction of two space-filling 4D brane-like sources situated within the extra dimensions and infer some of the properties of these sources using the formalism of point particle effective field theory (PPEFT), showing the sources are not vanilla objects like D branes. These tools relate the near-source asymptotic forms of bulk fields to source properties and have been extensively tested for more prosaic physical systems involving the back-reaction of small sources, such as the dependence of atomic energy levels on nuclear properties. We use it to determine the tension of the brane-like sources (that can be positive) and its derivatives. We verify that the solutions are in the weak coupling/large volume regime required to neglect quantum and ${\alpha }^{\prime }$ effects.

    ↳ hep-thgr-qchep-phJHEP(2025)·9 citations
23. 23*

    Investigation of pion-nucleon contributions to nucleon matrix elements

    Constantia Alexandrou🇨🇾 · Giannis Koutsou🇨🇾 · Yan Li🇨🇾 · Marcus Petschlies🇩🇪 · Ferenc Pittler🇨🇾

    We investigate contributions of excited states to nucleon matrix elements computed in lattice QCD by employing, in addition to the standard nucleon interpolating operator, pion-nucleon ($\pi$-$N$) operators. We solve a generalized eigenvalue problem (GEVP) to obtain an optimal interpolating operator that minimizes overlap with the $\pi$-$N$ states. We derive a variant of the standard application of the GEVP method, which allows for constructing 3-point correlation functions using the optimized interpolating operator without requiring the computationally demanding combination that includes $\pi$-$N$ operators in both sink and source. We extract nucleon matrix elements using two twisted mass fermion ensembles, one ensemble generated using pion mass of 346 MeV and one ensemble tuned to reproduce the physical value of the pion mass. Especially, we determine the isoscalar and isovector scalar, pseudoscalar, vector, axial, and tensor matrix elements. We include results obtained using a range of kinematic setups, including momentum in the sink. Our results using this variational approach are compared with previous results obtained using the same ensembles and multi-state fits without GEVP improvement. We find that for the physical mass point ensemble, the improvement, in terms of suppression of excited states using this method, is most significant for the case of the matrix elements of the isovector axial and pseudoscalar currents.

    ↳ hep-lathep-phnucl-thPRD(2024)·19 citations
24. 24*

    Vacuum Energy in Non-Supersymmetric Quasi-Realistic Heterotic-String Vacua with Fixed Moduli

    Eman Basaad🇬🇧 · Luke A. Detraux🇬🇧 · Alonzo R. Diaz Avalos🇬🇧 · Alon E. Faraggi🇬🇧 · Benjamin Percival🇬🇧

    Recently, Baykara, Tarazi and Vafa discussed the existence of quasicrystalline string vacua that contain a single neutral moduli, the dilaton, and studied compactifications of the non-supersymmetric $SO(16)\times SO(16)$ heterotic-string on these spaces. We discuss a specific class of quasi-realistic string vacua with similar properties that has been known since the late eighties and analyse the vacuum energy in several non-supersymmetric examples that correspond to compactifications of tachyon free ten dimensional vacua as well as compactifications of tachyonic ten dimensional vacua. Our analysis uses the Free Fermionic Formalism of the heterotic-string in four dimensions and employs asymmetric boundary conditions that project all the geometrical moduli by Generalised GSO projections. This methodology produces models with both positive and negative spacetime potential at one-loop.

    ↳ hep-thhep-phEPJC(2025)·11 citations
25. 25*

    Parity-breaking galaxy 4-point function from lensing by chiral gravitational waves

    Keisuke Inomata🇺🇸 · Leah Jenks🇺🇸 · Marc Kamionkowski🇺🇸

    Recent searches for parity breaking in the galaxy four-point correlation function, as well as the prospects for greatly improved sensitivity to parity breaking in forthcoming surveys, motivate the search for physical mechanisms that could produce such a signal. Here we show that a parity-violating galaxy four-point correlation function may be induced by lensing by a chiral gravitational-wave background. We estimate the amplitude of a signal that would be detectable with a current galaxy survey, taking into account constraints to the primordial gravitational-wave-background amplitude. We find that this mechanism is unlikely to produce a signal large enough to be seen with a galaxy survey but note that it may come within reach with future 21cm observations.

    ↳ astro-ph.COgr-qchep-phPRD(2025)·14 citations
26. 26*

    $\gamma$-Cascade V4: A Semi-Analytical Code for Modeling Cosmological Gamma-Ray Propagation

    Antonio Capanema🇧🇷 · Carlos Blanco🇺🇸

    Since the universe is not transparent to gamma rays with energies above around one hundred GeV, it is necessary to account for the interaction of high-energy photons with intergalactic radiation fields in order to model gamma-ray propagation. Here, we present a public numerical software for the modeling of gamma-ray observables. This code computes the effects on gamma-ray spectra from the development of electromagnetic cascades and cosmological redshifting. The code introduced here is based on the original $\gamma$-Cascade, and builds on it by improving its performance at high redshifts, introducing new propagation modules, and adding many more extragalactic radiation field models, which enables the ability to estimate the uncertainties inherent to EBL modeling. We compare the results of this new code to existing Monte Carlo electromagnetic transport models, finding good agreement within EBL uncertainties.

    ↳ astro-ph.HEastro-ph.COastro-ph.GAhep-phComput.Phys.Commun.(2025)·12 citations
27. 27*

    Holographic Gubser flow: A combined analytic and numerical study

    Toshali Mitra🇰🇷 · Sukrut Mondkar🇮🇳 · Ayan Mukhopadhyay🇮🇳 · Alexander Soloviev🇸🇮

    Gubser flow is an evolution with cylindrical and boost symmetries, which can be best studied by mapping the future wedge of Minkowski space (R${}^{3,1}$) to dS${}_3$ $\times$ $\mathbb{R}$ in a conformal relativistic theory. Here, we sharpen our previous analytic results and validate them via the first numerical exploration of the Gubser flow in a holographic conformal field theory. Remarkably, the leading generic behavior at large de Sitter time is free-streaming in transverse directions and the sub-leading behavior is that of a color glass condensate. We also show that Gubser flow can be smoothly glued to the vacuum outside the future Minkowski wedge generically given that the energy density vanishes faster than any power when extrapolated to early proper time or to large distances from the central axis. We find that at intermediate times the ratio of both the transverse and longitudinal pressures to the energy density converge approximately to a fixed point which is hydrodynamic only for large initial energy densities. We argue that our results suggest that the Gubser flow is better applied to collective behavior in jets rather than the full medium in the phenomenology of heavy ion collisions and can reveal new clues to the mechanism of confinement.

    ↳ hep-thgr-qchep-phJHEP(2024)·8 citations
28. 28*

    The Heat Kernel in Riemann Normal Coordinates and Multiloop Feynman Graphs in Curved Spacetime

    Igor Carneiro🇧🇷 · Gero von Gersdorff🇧🇷

    We present a formalism for computing arbitrary multi-loop Feynman graphs in curved spacetime using the heat kernel approach. To this end, we compute the off-diagonal components of the heat kernel in Riemann normal coordinates up to second order in the curvature.

    ↳ hep-thhep-phJHEP(2024)·5 citations

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