Fri·Dec 6, 2024Friday·December 6, 2024

1. 01*

   Tests of Three-Flavor Chiral Perturbation Theory

   Murray Moinester🇮🇱

   We review experimental tests of three-flavor (u,d,s) chiral perturbation theory (ChPT). These include measurements of pion and kaon polarizabilities, the chiral anomaly amplitudes for processes such as $\gamma \to \pi \pi \pi$, $\gamma \to \pi \pi \eta$, and $\gamma \to KK\pi$; as well as the lifetimes of the neutral pion and eta. These observables are extracted primarily through ultra-peripheral Primakoff scattering of high-energy particles from virtual photons in the Coulomb field of nuclei. Comparing data to two-flavor and three-flavor predictions allows us to evaluate how well ChPT describes light meson dynamics and the role of the strange quark in spontaneous chiral symmetry breaking.

   hep-phhep-exInt.J.Mod.Phys.A(2025)·5 citations
2. 02*

   Interpreting Transformers for Jet Tagging

   Aaron Wang🇺🇸 · Abhijith Gandrakota🇺🇸 · Jennifer Ngadiuba🇺🇸 · Vivekanand Sahu🇺🇸 · Priyansh Bhatnagar🇺🇸 · Elham E Khoda🇺🇸 · Javier Duarte🇺🇸

   Machine learning (ML) algorithms, particularly attention-based transformer models, have become indispensable for analyzing the vast data generated by particle physics experiments like ATLAS and CMS at the CERN LHC. Particle Transformer (ParT), a state-of-the-art model, leverages particle-level attention to improve jet-tagging tasks, which are critical for identifying particles resulting from proton collisions. This study focuses on interpreting ParT by analyzing attention heat maps and particle-pair correlations on the $\eta$-$\varphi$ plane, revealing a binary attention pattern where each particle attends to at most one other particle. At the same time, we observe that ParT shows varying focus on important particles and subjets depending on decay, indicating that the model learns traditional jet substructure observables. These insights enhance our understanding of the model's internal workings and learning process, offering potential avenues for improving the efficiency of transformer architectures in future high-energy physics applications.

   hep-phcs.LGhep-exphysics.data-an14 citations
3. 03*

   Darkonia at Colliders

   Yang Bai🇺🇸 · Susanne Westhoff🇳🇱

   Dark matter may form bound states in a dark sector with an attractive force between two dark matter particles. Searches for dark matter at colliders can differ dramatically from routine searches if bound states, dubbed darkonia, are produced and decay into visible Standard-Model particles. In this work, we use three representative models with scalar, pseudo-scalar, and vector force carriers to map out the darkonium signatures at both high-energy and low-energy colliders. Some of the bound states can be stable due to generalized parity and charge-conjugation symmetries, while others decay into light dark-force carriers, which subsequently can decay at a displaced vertex. New signatures with a mix of missing energy and multiple di-lepton or di-jet vertices reconstructing intermediate darkonium resonances are within reach at the LHC and Belle II.

   hep-phhep-exJHEP(2025)·1 citation
4. 04*

   Extended Poincare Symmetry Dictates Massive Scattering Amplitudes

   Yu-Han Ni🇨🇳 · Yi-Ning Wang🇨🇳 · Chao Wu🇨🇳 · Jiang-Hao Yu🇨🇳

   We identify an extended Poincare symmetry $ISO(2)\times ISO(3,1)$ for on-shell massive scattering amplitudes, transforming under the $U(2)$ Little group symmetry. Thus the one-particle state involves in both spin and transversality $t$ (related to chirality), and the spin-spinors are extended to the spin-transverality spinors. The massive spin-$s$ spinors with different transversality can be related by the $SO(5,1)$ symmetry, although the $U(2)$ Little group breaks the symmetry explicitly. The three-point massive amplitudes can be fully determined from the $T^{\pm }$ and $m$ generators, diagrammatically denoted as the mass insertion and chirality flip, which provide correspondence between massless ultraviolet and massive chiral-eigenstate amplitudes. Thus the massless on-shell technique can be utilized to construct higher-point tree- and loop-level massive amplitudes.

   hep-phhep-th5 citations
5. 05*

   Reconstruction of boosted and resolved multi-Higgs-boson events with symmetry-preserving attention networks

   Haoyang Li🇺🇸 · Marko Stamenkovic🇺🇸 · Alexander Shmakov🇺🇸 · Michael Fenton🇺🇸 · Darius Shih-Chieh Chao🇺🇸 · Kaitlyn Maiya White🇺🇸 · Caden Mikkelsen🇺🇸 · Jovan Mitic🇷🇸 · Cristina Mantilla Suarez🇺🇸 · Melissa Quinnan🇺🇸 · Greg Landsberg🇺🇸 · Harvey Newman🇺🇸 and 3 other authors

   The production of multiple Higgs bosons at the CERN LHC provides a direct way to measure the trilinear and quartic Higgs self-interaction strengths as well as potential access to beyond the standard model effects that can enhance production at large transverse momentum $p_{\mathrm{T}}$. The largest event fraction arises from the fully hadronic final state in which every Higgs boson decays to a bottom quark-antiquark pair ($b\bar{b}$). This introduces a combinatorial challenge known as the \emph{jet assignment problem}: assigning jets to sets representing Higgs boson candidates. Symmetry-preserving attention networks (SPA-Nets) have been been developed to address this challenge. However, the complexity of jet assignment increases when simultaneously considering both $H\to b\bar{b}$ reconstruction possibilities, i.e., two "resolved" small-radius jets each containing a shower initiated by a $b$-quark or one "boosted" large-radius jet containing a merged shower initiated by a $b\bar{b}$ pair. The latter improves the reconstruction efficiency at high $p_{\mathrm{T}}$. In this work, we introduce a generalization to the SPA-Net approach to simultaneously consider both boosted and resolved reconstruction possibilities and unambiguously interpret an event as "fully resolved'', "fully boosted", or in between. We report the performance of baseline methods, the original SPA-Net approach, and our generalized version on nonresonant $HH$ and $HHH$ production at the LHC. Considering both boosted and resolved topologies, our SPA-Net approach increases the Higgs boson reconstruction purity by 57--62\% and the efficiency by 23--38\% compared to the baseline method depending on the final state.

   hep-phcs.LGhep-exphysics.data-anJHEP(2025)·9 citations
6. 06*

   Eogenesis via the High-scale Electroweak Symmetry Restoration

   Wei Chao🇨🇳

   In this paper, we propose a novel electron-assisted Baryogenesis scenario that does not require explicit B-L violation, which is essential for the traditional Leptogenesis mechanism. This scenario is based on the assumption of high-scale electroweak symmetry restoration, which implies that the electron Yukawa interaction, crucial for the mechanism, does not reach thermal equilibrium before the electroweak sphaleron process is quenched in the early universe. Primordial charge asymmetries for chiral electrons, which can be generated through various mechanisms such as axion inflation, the evaporation of primordial black holes, or the CP-asymmetric decays of a heavy Higgs doublet, serve as the initial condition for the amplification of the baryon asymmetry through transport equations. Right-handed electron asymmetry is almost irrelevant to the baryon asymmetry due to high-scale electroweak symmetry restoration, leading to both a non-zero baryon asymmetry and the electron asymmetry. We dub this mechanism as the Eogenesis.

   hep-phastro-ph.COhep-th2 citations
7. 07*

   $\nu \bar{\nu }$ production, annihilation, and scattering at MeV temperatures and NLO accuracy

   G. Jackson🇫🇷 · M. Laine🇨🇭

   Interaction rates of neutrinos and antineutrinos within a QED plasma determine the dynamics of their decoupling in the early universe. We show how to define the relevant double-differential production, annihilation, and scattering rates at NLO. Integrating over these rates with specific weights, other quantities from the literature can be obtained, such as energy transfer rates, or a neutrino interaction rate. In the limit of massless electrons, we show that NLO corrections to the energy transfer rates are as small as those that enter the previously determined neutrino interaction rate, and only have a small influence on the neutrino decoupling parameter, $N_{\mathrm{eff}}$. For comparison, the influence of a finite electron mass is quantified at LO. Finally we provide a tabulation and fast interpolation routine for all double-differential rates, in order to allow for their use in non-approximate kinetic equations, which may further reduce the systematic uncertainties of the Standard Model prediction for $N_{\mathrm{eff}}$.

   hep-phastro-ph.COJCAP(2025)·7 citations
8. 08*

   $t\bar{t}t\bar{t}$: NLO QCD corrections in production and decays for the $3\ell$ channel

   Nikolaos Dimitrakopoulos🇩🇪

   We discuss the results for the four-top quark production process at the LHC at NLO accuracy in perturbative QCD for the $3\ell$ decay channel. The QCD corrections are applied in both the production and the decay stages of the four top quarks by employing the narrow-width approximation. The spin correlations are therefore preserved at NLO accuracy in QCD without any approximation. We summarize the impact of higher-order QCD effects by highlighting the sensitivity of the results on the cut applied on the invariant mass of the two hardest light jets in the process.

   hep-phSciPost Phys.Proc.(2026)·0 citations
9. 09*

   Renormalization of effective field theories via on-shell methods: the case of axion-like particles

   Luigi C. Bresciani🇮🇹 · Giacomo Brunello🇮🇹 · Gabriele Levati🇨🇭 · Pierpaolo Mastrolia🇮🇹 · Paride Paradisi🇮🇹

   We consider the most general axion-like particle effective field theory, including both CP-odd and CP-even types of interactions, and evaluate the corresponding renormalization group equations, improving and extending previous results in the literature. Our calculations exploit on-shell and unitarity-based methods. The relevant phase-space cut-integrals are carried out using different integration methods, among which the double-cut integration via Stokes' theorem proves to be technically simpler. A close comparison between the standard Feynman diagrammatic approach and the unitarity-based method enables us to explicitly verify the reduction of complexity in the latter case, along with a more direct and elegant way to establish a connection among anomalous dimensions of operators that are dual under the CP symmetry.

   hep-phhep-thJHEP(2025)·23 citations
10. 10*

    Gravitational wave and dark matter from Axion-Higgs string

    Yongtao Jia🇨🇳 · Ligong Bian🇨🇳

    Axions have long been considered plausible candidates for dark matter. The axion dark matter emitted from cosmic strings after the Peccei-Quinn (PQ) symmetry breaking in the early Universe was extensively simulated. In this work, we study dark matter and gravitational waves through the lattice simulation of the Axion-Higgs string. We gave the dark matter overproduction and the Big Bang nucleosynthesis bounds on the axion decay constant $f_a$ and the axion mass $m_a$ for axion-like particles, and found that the predicted gravitational wave spectra cannot be probed by the dataset of the current pulsar timing array experiments.

    hep-phastro-ph.COhep-thPRD(2025)·6 citations
11. 11*

    On axion properties in the 3-3-1 model with $U(1{)}_{B-L}$ and Peccei-Quinn symmetries

    H. N. Long🇻🇳 · H. T. Hung🇻🇳 · V. H. Binh🇻🇳 · A. B. Arbuzov🇷🇺

    The Peccei-Quinn ($PQ$) mechanism is applied to the $\mathrm{SU}(3{)}_{\mathrm{c}}\otimes \mathrm{SU}(3{)}_{\mathrm{L}}\otimes \mathrm{U}(1{)}_{\mathrm{X}}$ model with $U(1{)}_{B-L}$ symmetry. The structures in the $PQ$ charges of all fermions and scalar fields in the model are investigated by applying the invariant condition under the symmetry group transformations on all Yukawa interaction terms. All defined $PQ$ charges depend just on the $PQ$ charge of the complex singlet scalar field which causes the $U(1{)}_{PQ}$ spontaneous symmetry breaking in the model. The mixing and mass hierarchy in the scalar sector of the model are studied in detail. The constraints on the $PQ$ charges and imaginary parts of scalars are derived. It is shown that only neutral scalar fields carry $PQ$ charges while charged ones do not. As the result, the physical state of axion which obeys the invariance under $\mathrm{SU}(3{)}_{\mathrm{L}}\otimes \mathrm{U}(1{)}_{\mathrm{X}}$ and $PQ$ transformations, is a linear combination of all imaginary parts associated with the $X$ charges of scalar triplets. The anomaly axion-fermion interactions are presented. Explicit expressions for axion and light Standard Model (SM) like Higgs boson are shown. Mass of the axion and its coupling to photon are derived. The decays of the SM-like Higgs boson into a pair of either charged leptons or bottom quarks are presented and constrained. The triple-coupling axion-photon-photon arisen from kinetic terms of scalar fields is derived. Hence, the decay of axion into a pair of photons consists of two parts: the first is related to the anomaly coupling and the second is come from kinetic terms of scalar fields. The result shows that the new contribution can be helpful for searching axion with mass at hundred keV.

    hep-ph3 citations
12. 12*

    High-energy cLFV at $\mu$TRISTAN: HNL extensions of the Standard Model

    J. Kriewald🇸🇮 · E. Pinsard🇨🇭 · A. M. Teixeira🇫🇷

    Within the context of heavy neutral lepton (HNL) extensions of the Standard Model, we compute the cross-sections for ${\mu }^{+}{e}^{-}\to {\ell }_{\alpha }^{+}{\ell }_{\beta }^{-}$ scattering, as well as several angular observables. In particular, we investigate the future sensitivity of a $\mu$TRISTAN collider in discovering such charged lepton flavour violating processes and the potential constraining power of these searches on the parameter space of HNL models. Our results show that while low-energy probes of $\mu -e$ flavour violation do offer the most promising potential, the prospects for $e\tau$ and $\mu \tau$ flavour violation searches at $\mu$TRISTAN can exceed those of related low-energy probes (as well as flavour violating $Z$-pole processes at FCC-ee) by several orders of magnitude.

    hep-phJHEP(2025)·9 citations
13. 13*

    Unitarity bounds with subthreshold and anomalous cuts for $b$-hadron decays

    Abinand Gopal🇺🇸 · Nico Gubernari🇬🇧

    We derive a generalisation of the Boyd-Grinstein-Lebed (BGL) parametrization. Most form factors (FFs) in $b$-hadron decays exhibit additional branch cuts -- namely subthreshold and anomalous branch cuts -- beyond the ``standard'' unitarity cut. These additional cuts cannot be adequately accounted for by the BGL parametrization. For instance, these cuts arise in the FFs for $B\to D^{(\ast )}$, $B\to K^{(\ast )}$, and ${\Lambda }_b\to \Lambda$ processes, which are particularly relevant from a phenomenological standpoint. We demonstrate how to parametrize such FFs and derive unitarity bounds in the presence of subthreshold and/or anomalous branch cuts. Our work paves the way for a wide range of new FF analyses based solely on first principles, thereby minimising systematic uncertainties.

    hep-phmath-phmath.MPPRD(2025)·23 citations
14. 14*

    Recent Progress in Flavor Model Building

    Wolfgang Altmannshofer🇺🇸 · Admir Greljo🇨🇭

    The flavor puzzles remain among the most compelling open questions in particle physics. The striking hierarchies observed in the masses and mixing of charged fermions define the Standard Model (SM) flavor puzzle, a profound structural enigma pointing to physics beyond the SM. Simultaneously, the absence of deviations from SM predictions in precision measurements of flavor-changing neutral currents imposes severe constraints on new physics at the TeV scale, giving rise to the new physics flavor puzzle. This review article provides an overview of a selection of recent advancements in flavor model building, with a particular focus on attempts to address one or both of these puzzles within the quark sector.

    hep-phAnn.Rev.Nucl.Part.Sci.(2025)·24 citations
15. 15*

    Probing low-reheating scenarios with minimal freeze-in dark matter

    Nicolás Bernal🇦🇪 · Chee Sheng Fong🇧🇷 · Óscar Zapata🇨🇴

    The parameter space of freeze-in dark matter (DM) with mass $m_{\chi }$ through light dark photon (``minimal freeze-in DM'') is currently being probed by direct detection experiments through electron and nuclear recoil. Exploring the DM production in the mass range $10^{-2}\mathrm{MeV}<m_{\chi }<10^3$ TeV, we quantify the impact of quantum statistics and the reheating dynamics (beyond the instantaneous reheating approximation) on the DM production in the early universe, in particular, the dependence on the cosmic equation of state and the scaling of the temperature of the Standard Model bath during reheating. Special cases corresponding to matter-domination and kination are carefully studied. To fit the entire observed DM relic abundance, low-temperature reheating scenarios require an increase in the coupling between dark and visible sectors which, in turn, enhances the regions of the parameter space that are already tested and will be probed by next-generation direct detection experiments for diverse reheating scenarios.

    hep-phJHEP(2025)·30 citations
16. 16*

    Learning Symmetry-Independent Jet Representations via Jet-Based Joint Embedding Predictive Architecture

    Subash Katel🇺🇸 · Haoyang Li🇺🇸 · Zihan Zhao🇺🇸 · Raghav Kansal🇺🇸 · Farouk Mokhtar🇺🇸 · Javier Duarte🇺🇸

    In high energy physics, self-supervised learning (SSL) methods have the potential to aid in the creation of machine learning models without the need for labeled datasets for a variety of tasks, including those related to jets -- narrow sprays of particles produced by quarks and gluons in high energy particle collisions. This study introduces an approach to learning jet representations without hand-crafted augmentations using a jet-based joint embedding predictive architecture (J-JEPA), which aims to predict various physical targets from an informative context. As our method does not require hand-crafted augmentation like other common SSL techniques, J-JEPA avoids introducing biases that could harm downstream tasks. Since different tasks generally require invariance under different augmentations, this training without hand-crafted augmentation enables versatile applications, offering a pathway toward a cross-task foundation model. We finetune the representations learned by J-JEPA for jet tagging and benchmark them against task-specific representations.

    hep-phcs.LGhep-exphysics.data-an11 citations
17. 17*

    Lie, Noether, Kosmann, and Diffeomorphism Anomalies Redux

    Taeyeon Kim🇰🇷 · Piljin Yi🇰🇷

    The Noether procedure carries an inherent ambiguity due to the necessary local extension, no longer a symmetry, of the global symmetry. The gauging should fix the ambiguity once and for all, however, and, for translations, the general covariance demands us to use the Lie derivative. We argue that, with this alone and without any further tweaking, the Noether energy-momentum $\hat{\mathbb{T}}$ must equal the symmetric counterpart, $T$, inevitably and show the equality explicitly for general tensors. For spinors, a subtlety with the Lie derivative itself enters the issue and leads us to the Kosmann lift, often unnoticed by the physics community, from which $T=\hat{\mathbb{T}}$ again emerges straightforwardly and in a naturally symmetric form. Finally, we address how the same Kosmann lift affects the anomaly computations and show that the diffeomorphism anomaly from the seminal paper must be halved, while the venerable anomaly polynomials themselves stand unaffected. We discuss the ramifications of these findings.

    ↳ hep-thgr-qchep-ph3 citations
18. 18*

    Evidence of a CP broken deconfined phase in 4D SU(2) Yang-Mills theory at $\theta =\pi$ from imaginary $\theta$ simulations

    Mitsuaki Hirasawa🇮🇹 · Masazumi Honda🇯🇵 · Akira Matsumoto🇯🇵 · Jun Nishimura🇯🇵 · Atis Yosprakob🇯🇵

    The spontaneous breaking of CP symmetry in 4D SU($N$) pure Yang-Mills theory at $\theta =\pi$ has recently attracted much attention in the context of the higher-form symmetry and the 't Hooft anomaly matching condition. Here we use Monte Carlo simulations to study the $N=2$ case, which is interesting since it is the case opposite to the large-$N$ limit, where explicit calculations are available. In order to circumvent the severe sign problem due to the $\theta$ term for real $\theta$, we first obtain results at imaginary $\theta$, where the sign problem is absent, and make an analytic continuation to real $\theta$. We use the stout smearing in defining the $\theta$ term in the action to be used in our simulations. Thus we obtain the expectation value of the topological charge and the deconfining temperature at $\theta =\pi$, and provide an evidence that the CP symmetry, which is spontaneously broken at low temperature, gets restored \emph{strictly above} the deconfining temperature. This conclusion is consistent with the anomaly matching condition and yet differs from the prediction in the large-$N$ limit.

    ↳ hep-thhep-lathep-phJHEP(2025)·12 citations
19. 19*

    A simple model to investigate jet quenching and correlated errors for centrality-dependent nuclear-modification factors in relativistic heavy-ion collisions

    Ron A Soltz🇺🇸 · Dhanush A Hangal🇺🇸 · Aaron Angerami🇺🇸

    We apply Bayesian techniques to compare a simple, empirical model for jet-quenching in heavy-ion collisions to centrality-dependent jet-$R_{AA}$ measured by ATLAS for Pb+Pb collisions at $\sqrt{s_{NN}}=5.02$~TeV. We find that the $R_{AA}$ values for central collisions are adequately described with a model for the mean $p_T$-dependent jet energy-loss using only 2-parameters. This model is extended by incorporating 2D initial geometry information from TRENTO and compared to centrality-dependent $R_{AA}$ values. We find that the results are sensitive to value of the jet-quenching formation time, ${\tau }_f$, and that the optimal value of ${\tau }_f$ varies with the assumed path-length dependence of the energy-loss. We construct a covariance error matrix for the data from the $p_T$ dependent contributions to the ATLAS systematic errors and perform Bayesian calibrations for several different assumptions for the systematic error correlations. We show that most-probable functions and ${\chi }^2$ values are sensitive to assumptions made when fitting to correlated errors.

    ↳ nucl-thhep-phnucl-exPRC(2025)·7 citations
20. 20*

    Probing quantum entanglement using Higgs to ZZ* to 4 leptons at ATLAS

    Mira Varma🇺🇸

    Quantum entanglement, a fundamental feature of quantum mechanics, has become a powerful tool impacting various areas of physics. In this proceeding, we investigate the presence of quantum entanglement within the Higgs to ZZ* (HZZ*) interaction at the ATLAS experiment. Utilizing quantum tomography techniques, we extract the complete spin density matrix characterizing the HZZ* interaction from ATLAS Standard Monte Carlo (MC) HZZ* 4l Run2 samples. We then evaluate the presence of quantum entanglement in the system using the derived spin density matrix. Our investigation sheds light on the entanglement properties within the HZZ* interaction, which offers valuable insights into its quantum characteristics.

    ↳ quant-phhep-ph0 citations
21. 21*

    A Systematic Lagrangian Formulation for Quantum and Classical Gravity at High Energies

    Ira Z. Rothstein🇺🇸 · Michael Saavedra🇺🇸

    We derive a systematic Lagrangian approach for quantum gravity in the super-Planckian limit where $s\gg M_{pl}^2\gg t$. The action can be used to calculate to arbitrary accuracy in the quantum and classical expansion parameters ${\alpha }_Q=\frac{t}{M_{pl}^2}$ and ${\alpha }_C=\frac{st}{M_{pl}^4}$, respectively, for the scattering of massless particles. The perturbative series contains powers of $\log (s/t)$ which can be resummed using a rapidity renormalization group equation (RRGE) that follows from a factorization theorem which allows us to write the amplitude as a convolution of a soft and collinear jet functions. We prove that the soft function is composed of an infinite tower of operators which do not mix under rapidity renormalization. The running of the leading order (in $G$) operator leads to the graviton Regge trajectory while the next to leading operator running corresponds to the gravitational BFKL equation. For the former, we find agreement with one of the two results previously presented in the literature, while for the ladder our result agrees (up to regulator dependent pieces) with those of Lipatov. We find that the convolutive piece of the gravitational BFKL kernel is the square of that of QCD. The power counting simplifies considerably in the classical limit where we can use our formalism to extract logs at any order in the PM expansion. The leading log at any order in the PM expansion can be calculated without going beyond one loop. The log at $(2N+1)$ order in the Post-Minkowskian expansion follows from calculating the one loop anomalous dimension for the $N+1$th order piece of the soft function and perturbatively solving the RRGE $N-1$ times. The factorization theorem implies that the classical logs which arise alternate between being real and imaginary in nature as $N$ increases.

    ↳ hep-thgr-qchep-ph24 citations
22. 22*

    Block Lanczos algorithm for lattice QCD spectroscopy and matrix elements

    Daniel C. Hackett🇺🇸 · Michael L. Wagman🇺🇸

    Recent work introduced a new framework for analyzing correlation functions with improved convergence and signal-to-noise properties, as well as rigorous quantification of excited-state effects, based on the Lanczos algorithm and spurious eigenvalue filtering with the Cullum-Willoughby test. Here, we extend this framework to the analysis of correlation-function matrices built from multiple interpolating operators in lattice quantum chromodynamics (QCD) by constructing an oblique generalization of the block Lanczos algorithm, as well as a new physically motivated reformulation of the Cullum-Willoughby test that generalizes to block Lanczos straightforwardly. The resulting block Lanczos method directly extends generalized eigenvalue problem (GEVP) methods, which can be viewed as applying a single iteration of block Lanczos. Block Lanczos provides qualitative and quantitative advantages over GEVP methods analogous to the benefits of Lanczos over the standard effective mass, including faster convergence to ground- and excited-state energies, explicitly computable two-sided error bounds, straightforward extraction of matrix elements of external currents, and asymptotically constant signal-to-noise. No fits or statistical inference are required. Proof-of-principle calculations are performed for noiseless mock-data examples as well as two-by-two proton correlation-function matrices in lattice QCD.

    ↳ hep-latcs.NAhep-phmath.NA+1PRD(2025)·33 citations
23. 23*

    Ab initio calculations of overlap integrals for $\mu \to e$ conversion in nuclei

    Matthias Heinz🇩🇪 · Martin Hoferichter🇨🇭 · Takayuki Miyagi🇩🇪 · Frederic Noël🇨🇭 · Achim Schwenk🇩🇪

    The rate for $\mu \to e$ conversion in nuclei is set to provide the most stringent test of lepton-flavor symmetry and a window into physics beyond the Standard Model. However, to disentangle new lepton-flavor-violating interactions, in combination with information from $\mu \to e\gamma$ and $\mu \to 3e$, it is critical that uncertainties at each step of the analysis be controlled and fully quantified. In this regard, nuclear response functions related to the coupling to neutrons are notoriously problematic, since they are not directly constrained by experiment. We address these shortcomings by combining ab initio calculations with a recently improved determination of charge distributions from electron scattering by exploiting strong correlations among charge, point-proton, and point-neutron radii and densities. We present overlap integrals for ${}^{27}$Al, ${}^{48}$Ca, and ${}^{48}$Ti including full covariance matrices, allowing, for the first time, for a comprehensive consideration of nuclear structure uncertainties in the interpretation of $\mu \to e$ experiments.

    ↳ nucl-thhep-exhep-phnucl-exPLB(2025)·16 citations
24. 24*

    Antimatter

    Beatriz Gato-Rivera🇪🇸

    In this article we concisely explain: what antimatter is, its differentiation between primordial and secondary, how it is produced, where it can be found, the experiments carried out at CERN to create and analyze antiatoms, the problem of the matter-antimatter asymmetry, and the medical and technological applications of antimatter in our society.

    ↳ physics.pop-phastro-ph.HEhep-exhep-ph+10 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.