Mon·Jul 3, 2023Monday·July 3, 2023

1. 01*

   Confronting Dark Matter Freeze-In during Reheating with Constraints from Inflation

   Mathias Becker🇩🇪 · Emanuele Copello🇩🇪 · Julia Harz🇩🇪 · Jonas Lang🇩🇪 · Yong Xu🇩🇪

   We investigate the production of particle Dark Matter (DM) in a minimal freeze-in model considering a non-instantaneous reheating phase after inflation. We demonstrate that for low reheating temperatures, bosonic or fermionic reheating from monomial potentials can lead to a different evolution in the DM production and hence to distinct predictions for the parent particle lifetime and mass, constrained by long-lived particle (LLP) searches. We highlight that such scenario predicts parent particle decay lengths larger compared to using the instantaneous reheating approximation. Moreover, we demonstrate the importance of an accurate definition of the reheating temperature and emphasize its relevance for the correct interpretation of experimental constraints. We explore different models of inflation, which can lead to the considered reheating potential. We find that the extent to which the standard DM freeze-in production can be modified crucially depends on the underlying inflationary model. Based on the latest CMB constraints, we derive lower limits on the decay length of the parent particle and confront these results with the corresponding reach of LLP searches. Our findings underscore the impact of the specific dynamics of inflation on DM freeze-in production and highlight their importance for the interpretation of collider signatures. At the same time, our results indicate the potential for LLP searches to shed light on the underlying dynamics of reheating.

   hep-phastro-ph.COhep-exJCAP(2024)·41 citations
2. 02*

   Can supercooled phase transitions explain the gravitational wave background observed by pulsar timing arrays?

   Peter Athron🇨🇳 · Andrew Fowlie🇨🇳 · Chih-Ting Lu🇨🇳 · Lachlan Morris🇦🇺 · Lei Wu🇨🇳 · Yongcheng Wu🇨🇳 · Zhongxiu Xu🇨🇳

   Several pulsar timing array collaborations recently reported evidence of a stochastic gravitational wave background (SGWB) at nHz frequencies. Whilst the SGWB could originate from the merger of supermassive black holes, it could be a signature of new physics near the 100 MeV scale. Supercooled first-order phase transitions (FOPTs) that end at the 100 MeV scale are intriguing explanations, because they could connect the nHz signal to new physics at the electroweak scale or beyond. Here, however, we provide a clear demonstration that it is not simple to create a nHz signal from a supercooled phase transition, due to two crucial issues that could rule out many proposed supercooled explanations and should be checked. As an example, we use a model based on non-linearly realized electroweak symmetry that has been cited as evidence for a supercooled explanation. First, we show that a FOPT cannot complete for the required transition temperature of around 100 MeV. Such supercooling implies a period of vacuum domination that hinders bubble percolation and transition completion. Second, we show that even if completion is not required or if this constraint is evaded, the Universe typically reheats to the scale of any physics driving the FOPT. The hierarchy between the transition and reheating temperature makes it challenging to compute the spectrum of the SGWB.

   hep-phastro-ph.COPRL(2024)·108 citations
3. 03*

   Exploring Bell inequalities and quantum entanglement in vector boson scattering

   R. A. Morales🇦🇷

   Quantum properties of vector boson scattering $V_1^{\prime }{V}_2^{\prime }\to V_1{V}_2$, related to entanglement and violation of Bell inequalities, are explored in this paper. The analysis is based on the construction of the polarization density matrix associated to the final state $V_1{V}_2$ by means of the computation of the corresponding tree level amplitudes within the Standard Model. The aim of this work is to determine the regions of the phase space where the final vector bosons after the scattering result entangled and if is it possible to test the Bell inequalities in those regions. We found that in all cases the entanglement is present. The amount of it depends on the process and the Maximally Entangled state is reached in some particular channels. Concerning the Bell inequality, it could be also tested in certain kinematical regions for some of these processes. This work is a first step in the analysis of these quantum properties for this kind of processes and it is postponed for future studies the reconstruction of the polarization density matrix and the related quantum parameters from experimental data through Monte-Carlo simulations using quantum tomography techniques.

   hep-phquant-phEur.Phys.J.Plus(2023)·79 citations
4. 04*

   Searching for heavy neutral lepton and lepton number violation through VBS at high-energy muon colliders

   Tong Li🇨🇳 · Chang-Yuan Yao🇨🇳 · Man Yuan🇨🇳

   High-energy muon collider can play as an emitter of electroweak gauge bosons and thus leads to substantial vector boson scattering (VBS) processes. In this work, we investigate the production of heavy neutral lepton (HNL) $N$ and lepton number violation (LNV) signature through VBS at high-energy muon colliders. VBS induces LNV processes $W^{\pm }Z/\gamma \to {\ell }^{\pm }N\to {\ell }^{\pm }{\ell }^{\pm }{W}^{\mp }\to {\ell }^{\pm }{\ell }^{\pm }q{\bar{q}}^{\prime }$ with an on-shell HNL $N$ at ${\mu }^{+}{\mu }^{-}$ colliders. In analogy to neutrinoless double-beta decay with the HNL in t-channel, the LNV signature $W^{+}{W}^{+}\to {\ell }^{+}{\ell }^{+}$ can also happen via VBS at same-sign muon collider. They provide clean and robust LNV signatures to tell the nature of Majorana HNLs and thus have more advantageous benefits than direct $\mu \mu$ annihilation. We analyze the potential of searching for Majorana HNL and obtain the exclusion limits on mixing $V_{\ell N}$. Based on this same-sign lepton signature, we also obtain the sensitivity of muon collider to the Weinberg operator.

   hep-phJHEP(2023)·29 citations
5. 05*

   Modeling the $R$-ratio and hadronic contributions to $g-2$ with a Treed Gaussian Process

   Andrew Fowlie🇨🇳 · Qiao Li🇨🇳

   The BNL and FNAL measurements of the anomalous magnetic moment of the muon disagree with the Standard Model (SM) prediction by more than $4\sigma$. The hadronic vacuum polarization (HVP) contributions are the dominant source of uncertainty in the SM prediction. There are, however, tensions between different estimates of the HVP contributions, including data-driven estimates based on measurements of the $R$-ratio. To investigate that tension, we modeled the unknown $R$-ratio as a function of CM energy with a treed Gaussian process (TGP). This is a principled and general method grounded in data-science that allows complete uncertainty quantification and automatically balances over- and under-fitting to noisy data. Our tool yields exploratory results are similar to previous ones and we find no indication that the $R$-ratio was previously mismodeled. Whilst we advance some aspects of modeling the $R$-ratio and develop new tools for doing so, a competitive estimate of the HVP contributions requires domain-specific expertise and a carefully curated database of measurements.

   hep-phEPJC(2023)·5 citations
6. 06*

   Nanohertz gravitational waves from cosmic strings and dark photon dark matter

   Naoya Kitajima🇯🇵 · Kazunori Nakayama🇯🇵

   The recent observations by pulsar timing array (PTA) experiments suggest the existence of stochastic gravitational wave background in the nano-Hz range. It can be a hint for the new physics and cosmic string is one of the promising candidate. In this paper, we study the implication of the PTA result for cosmic strings and dark photon dark matter produced by the decay of cosmic string loops. It can simultaneously explain the PTA result and present dark matter abundance for the dark photon mass m~10^{-6}--10^{-4}eV. Implications for the gravitational wave detection with multi-frequency bands are also discussed.

   hep-phastro-ph.COPLB(2023)·62 citations
7. 07*

   Searching for saturation in forward dijet production at the LHC

   A. van Hameren🇵🇱 · H. Kakkad🇵🇱 · P. Kotko🇵🇱 · K. Kutak🇵🇱 · S. Sapeta🇵🇱

   We review recent results for forward jests at the LHC and EIC as obtained within small-x Improved Transverse Momentum Dependent factorization (ITMD). In addition to elementary overview of various approaches to perturbative QCD at high energy, including High Energy Factorization, Color Glass Condensate and ITMD, we describe the Monte Carlo implementation and discuss the existing and unpublished phenomenological results for forward dijets.

   hep-phhep-exEPJC(2023)·28 citations
8. 08*

   Flavor violating Higgs and $Z$ decays at FCC-ee

   Jernej F. Kamenik🇸🇮 · Arman Korajac🇸🇮 · Manuel Szewc🇺🇸 · Michele Tammaro🇸🇮 · Jure Zupan🇺🇸

   Recent advances in $b$, $c$, and $s$ quark tagging coupled with novel statistical analysis techniques will allow future high energy and high statistics electron-positron colliders, such as the FCC-ee, to place phenomenologically relevant bounds on flavor violating Higgs and $Z$ decays to quarks. We assess the FCC-ee reach for $Z/h\to bs,cu$ decays as a function of jet tagging performance. We also update the SM predictions for the corresponding branching ratios, as well as the indirect constraints on the flavor violating Higgs and $Z$ couplings to quarks. Using type III two Higgs doublet model as an example of beyond the standard model physics, we show that the searches for $h\to bs,cu$ decays at FCC-ee can probe new parameter space not excluded by indirect searches. We also reinterpret the FCC-ee reach for $Z\to bs,cu$ in terms of the constraints on models with vectorlike quarks.

   hep-phPRD(2024)·33 citations
9. 09*

   On the Effects of Quantum Decoherence in a Future Supernova Neutrino Detection

   Marcos V. dos Santos🇧🇷 · Pedro C. de Holanda🇧🇷 · Pedro Dedin Neto🇧🇷 · Ernesto Kemp🇧🇷

   Quantum decoherence effects in neutrinos, described by the open quantum systems formalism, serve as a gateway to explore potential new physics, including quantum gravity. Previous research extensively investigated these effects across various neutrino sources, imposing stringent constraints on the spontaneous loss of coherence. In this study, we demonstrate that even within the Supernovae environment, where neutrinos are released as incoherent states, quantum decoherence could influence the flavor equipartition of $3\nu$ mixing. Additionally, we examine the potential energy dependence of quantum decoherence parameters ($\Gamma ={\Gamma }_0(E/E_0{)}^n$) with different power laws ($n=0,2,5/2$). Our findings indicate that future-generation detectors (DUNE, Hyper-K, and JUNO) can significantly constrain quantum decoherence effects under different scenarios. For a Supernova located 10 kpc away from Earth, DUNE could potentially establish $3\sigma$ bounds of $\Gamma \le 6.2\times 10^{-14}$ eV in the normal mass hierarchy (NH) scenario, while Hyper-K could impose a $2\sigma$ limit of $\Gamma \le 3.6\times 10^{-14}$ eV for the inverted mass hierarchy (IH) scenario with $n=0$ - assuming no energy exchange between the neutrino subsystem and non-standard environment ($[H,V_p]=0$). These limits become even more restrictive for a closer Supernova. When we relax the assumption of energy exchange ($[H,V_p]\ne 0$), for a 10 kpc SN, DUNE can establish a $3\sigma$ limit of ${\Gamma }_8\le 4.2\times 10^{-28}$ eV for NH, while Hyper-K could constrain ${\Gamma }_8\le 1.3\times 10^{-27}$ eV for IH ($n=0$) with $2\sigma$, representing the most stringent bounds reported to date. Furthermore, we examine the impact of neutrino loss during propagation for future Supernova detection.

   hep-phastro-ph.HEhep-thPRD(2023)·10 citations
10. 10*

    Next-to-leading power corrections to the event shape variables

    Neelima Agarwal · Melissa van Beekveld🇬🇧 · Eric Laenen🇳🇱 · Shubham Mishra🇮🇳 · Ayan Mukhopadhyay🇮🇳 · Anurag Tripathi🇮🇳

    We investigate the origin of next-to-leading power corrections to the event shapes thrust and $c$-parameter, at next-to-leading order. For both event shapes we trace the origin of such terms in the exact calculation, and compare with a recent approach involving the eikonal approximation and momentum shifts that follow from the Low-Burnett-Kroll-Del Duca theorem. We assess the differences both analytically and numerically. For the $c$-parameter both exact and approximate results are expressed in terms of elliptic integrals, but near the elastic limit it exhibits patterns similar to the thrust results.

    hep-phPramana(2024)·14 citations
11. 11*

    HBT signature for clustered substructures probing primordial inhomogeneity in hot and dense QCD matter

    Kenji Fukushima🇯🇵 · Yoshimasa Hidaka🇯🇵 · Katsuya Inoue🇯🇵 · Kenta Shigaki🇯🇵 · Yorito Yamaguchi🇯🇵

    We propose a novel approach to probe primordial inhomogeneity in hot and dense matter which could be realized in non-central heavy-ion collisions. Although the Hanbury Brown and Twiss (HBT) interferometry is commonly used to infer the system size, the cluster size should be detected if substructures emerge in space. We demonstrate that a signal peak in the HBT two-particle correlation stands at the relative momentum corresponding to the spatial scale of pseudo one-dimensional modulation. We assess detectability using the data prepared by an event generator (AMPT model) with clustering implemented in the particle distribution.

    hep-phnucl-exnucl-thPRC(2024)·13 citations
12. 12*

    Properties of the $T_{cc}(3875{)}^{+}$ and $T_{\bar{c}\bar{c}}(3875{)}^{-}$ (and their heavy-quark spin partners) in nuclear matter

    Victor Montesinos🇪🇸 · Miguel Albaladejo🇪🇸 · Juan Nieves🇪🇸 · Laura Tolos🇪🇸

    We discuss the modification of the properties of the tetraquark-like $T_{cc}(3875{)}^{+}$ and $T_{\bar{c}\bar{c}}(3875{)}^{-}$ states in dense nuclear matter. We consider the $T_{cc}^{+}$ and $T_{\bar{c}\bar{c}}^{-}$ in vacuum as purely isoscalar $D^{\ast }D$ and $\overline{D}{}^{\ast }\overline{D}$ $S$-wave bound states, respectively, dynamically generated from a heavy-quark effective interaction between the charmed mesons. We compute the $D$, $\overline{D}$, $D^{\ast }$, and $\overline{D}{}^{\ast }$ spectral functions embedded in a nuclear medium and use them to determine the corresponding $T_{cc}^{+}$ and $T_{\bar{c}\bar{c}}^{-}$ self energies and spectral functions. We find important modifications of the $D^{\ast }D$ and $\overline{D}{}^{\ast }\overline{D}$ scattering amplitudes and of the pole position of these exotic states already for ${\rho }_0/2$, with ${\rho }_0$ the normal nuclear density. We also discuss the dependence of these results on the $D^{\ast }D$ ($\overline{D}{}^{\ast }\overline{D}$) molecular component in the $T_{cc}^{+}$ ($T_{\bar{c}\bar{c}}^{-}$ ) wave-function. Owing to the different nature of the $D^{(\ast )}N$ and $\overline{D}{}^{(\ast )}N$ interactions, we find characteristic changes of the in-medium properties of the $T_{cc}(3875{)}^{+}$ and $T_{\bar{c}\bar{c}}(3875{)}^{-}$, which become increasingly visible as the density increases. The experimental confirmation of the found distinctive density-pattern will give support to the molecular picture of these tetraquark-like states, since in the case they were colourless compact quark structures the density behaviour of their respective nuclear medium spectral functions would likely be similar. Finally, we perform similar analyses for the isoscalar $J^P=1^{+}$ heavy-quark spin symmetry partners of the $T_{cc}^{+}$ ($T_{cc}^{\ast +}$) and the $T_{\bar{c}\bar{c}}^{-}$ ($T_{\bar{c}\bar{c}}^{\ast -}$) by considering the $D^{\ast 0}{D}^{\ast +}$ and $\overline{D}{}^{\ast 0}{D}^{\ast -}$ scattering $T-$matrices.

    hep-phnucl-thPRC(2023)·25 citations
13. 13*

    SModelS v2.3: enabling global likelihood analyses

    Mohammad Mahdi Altakach🇫🇷 · Sabine Kraml🇫🇷 · Andre Lessa🇧🇷 · Sahana Narasimha🇦🇹 · Timothée Pascal🇫🇷 · Wolfgang Waltenberger🇦🇹

    We present version 2.3 of SModelS, a public tool for the fast reinterpretation of LHC searches for new physics on the basis of simplified-model results. The main new features are a database update with the latest available experimental results for full Run 2 luminosity, comprising in particular a large variety of electroweak-ino searches, and the ability to combine likelihoods from different analyses. This enables statistically more rigorous constraints and opens the way for global likelihood analyses for LHC searches. The physics impact is demonstrated for the electroweak-ino sector of the minimal supersymmetric standard model.

    hep-phhep-exSciPost Phys.(2023)·32 citations
14. 14*

    Proton structure functions in the dipole picture at next-to-leading order

    Henri Hänninen🇫🇮 · Heikki Mäntysaari🇫🇮 · Risto Paatelainen🇫🇮 · Jani Penttala🇫🇮

    We predict heavy quark production cross sections in Deep Inelastic Scattering at high energy by applying the CGC effective theory. We demonstrate that when the calculation is performed consistently at next-to-leading order accuracy with massive quarks it becomes possible, for the first time in the dipole picture with perturbatively calculated center-of-mass energy evolution, to simultaneously describe both light and heavy quark production data at small $x$. We furthermore show how the heavy quark cross section data provides additional strong constraints on the extracted non-perturbative initial condition for the small-$x$ evolution equations.

    hep-phnucl-th0 citations
15. 15*

    (N)NLO+NLL' accurate predictions for plain and groomed 1-jettiness in neutral current DIS

    Max Knobbe🇩🇪 · Daniel Reichelt🇬🇧 · Steffen Schumann🇩🇪

    The possibility to reanalyse data taken by the HERA experiments offers the chance to study modern QCD jet and event-shape observables in deep-inelastic scattering. To address this, we compute resummed and matched predictions for the 1-jettiness distribution in neutral current DIS with and without grooming the hadronic final state using the soft-drop technique. Our theoretical predictions also account for non-perturbative corrections from hadronisation through parton-to-hadron level transfer matrices extracted from dedicated Monte Carlo simulations with Sherpa. To estimate parameter uncertainties in particular for the beam-fragmentation modelling we derive a family of replica tunes to data from the HERA experiments. While NNLO QCD normalisation corrections to the NLO+NLL' prediction are numerically small, hadronisation corrections turn out to be quite sizeable. However, soft-drop grooming significantly reduces the impact of non-perturbative contributions. We supplement our study with hadron-level predictions from Sherpa based on the matching of NLO QCD matrix elements with the parton shower. Good agreement between the predictions from the two calculational methods is observed.

    hep-phhep-exJHEP(2023)·33 citations
16. 16*

    Ambiguities in Partial Wave Analysis of Two Spinless Meson Photoproduction

    JPAC Collaboration: W. A. Smith🇺🇸 · D. I. Glazier🇬🇧 · V. Mathieu🇪🇸 · M. Albaladejo🇪🇸 · M. Albrecht🇺🇸 · Z. Baldwin🇺🇸 · C. Fernández-Ramírez🇪🇸 · N. Hammoud🇵🇱 · M. Mikhasenko🇩🇪 · G. Montaña🇺🇸 · R. J. Perry🇪🇸 · A. Pilloni🇮🇹 and 3 other authors

    We describe the formalism to analyze the mathematical ambiguities arising in partial-wave analysis of two spinless mesons produced with a linearly polarized photon beam. We show that partial waves are uniquely defined when all accessible observables are considered, for a wave set which includes $S$ and $D$ waves. The inclusion of higher partial waves does not affect our results, and we conclude that there are no mathematical ambiguities in partial-wave analysis of two mesons produced with a linearly polarized photon beam. We present Monte Carlo simulations to illustrate our results.

    hep-phnucl-exnucl-thPRD(2023)·10 citations
17. 17*

    Superheavy quasi-stable strings and walls bounded by strings in the light of NANOGrav 15 year data

    George Lazarides🇬🇷 · Rinku Maji🇰🇷 · Qaisar Shafi🇺🇸

    Composite topological structures such as superheavy "quasi-stable strings" (QSS) and "walls bounded by strings" (WBS) arise in realistic extensions of the Standard Model of high energy physics. We show that the gravitational radiation emitted in the early universe by these two unstable structures with a dimensionless string tension $G\mu \approx 10^{-6}$ is consistent with the NANOGrav evidence of low frequency gravitational background as well as the recent LIGO-VIRGO constraints, provided the superheavy strings and monopoles experience a certain amount of inflation. For the case of walls bounded by strings, the domain walls arise from the spontaneous breaking of a remnant discrete gauge symmetry around the electroweak scale. The quasi-stable strings, on the other hand, arise from a two step breaking of a local gauge symmetry. The monopoles appear from the first breaking and get connected to strings that arise from the second breaking. Both composite structures decay by emitting gravitational waves over a wide frequency range. The Bayes factors for QSS and WBS relative to the inspiraling supermassive black hole binaries are estimated to be about 60 and 30 respectively, which are comparable with that of metastable strings and cosmic superstrings.

    hep-phastro-ph.COPRD(2023)·103 citations
18. 18*

    Implication of nano-Hertz stochastic gravitational wave on dynamical dark matter through a dark first-order phase transition

    Siyu Jiang🇨🇳 · Aidi Yang🇨🇳 · Jiucheng Ma🇨🇳 · Fa Peng Huang🇨🇳

    For the first time, the expected stochastic gravitational wave background is probably discovered after observing the Hellings Downs correlation curve by several pulsar timing array (PTA) collaborations around the globe including NANOGrav, European PTA, Parkes PTA, and Chinese PTA. These new observations can help to explore or constrain the dark matter (DM) formation mechanisms in the early Universe. We study the implication of those results on the dynamical DM formation mechanisms through a dark first-order phase transition in the early Universe. Both the Q-ball DM and super-cool DM are investigated in the strong super-cooling dark phase transition scenario which may give an interpretation of the observed stochastic gravitational wave background.

    hep-phClass.Quant.Grav.(2024)·66 citations
19. 19*

    Axionic domain walls at Pulsar Timing Arrays: QCD bias and particle friction

    Simone Blasi🇧🇪 · Alberto Mariotti🇧🇪 · Aäron Rase🇧🇪 · Alexander Sevrin🇧🇪

    The recent results from the Pulsar Timing Array (PTA) collaborations show the first evidence for the detection of a stochastic background of gravitational waves at the nHz frequencies. This discovery has profound implications for the physics of both the late and the early Universe. In fact, together with the possible interpretation in terms of super massive black hole binaries, many sources in the early Universe can provide viable explanations as well. In this paper, we study the gravitational wave background sourced by a network of axion-like-particle (ALP) domain walls at temperatures around the QCD crossover, where the QCD-induced potential provides the necessary bias to annihilate the network. Remarkably, this implies a peak amplitude at frequencies around the sensitivity range of PTAs. We extend previous analysis by taking into account the unavoidable friction on the network stemming from the topological coupling of the ALP to QCD in terms of gluon and pion reflection off the domain walls at high and low temperatures, respectively. We identify the regions of parameter space where the network annihilates in the scaling regime ensuring compatibility with the PTA results, as well as those where friction can be important and a more detailed study around the QCD crossover is required.

    hep-phastro-ph.COJHEP(2023)·85 citations
20. 20*

    A proposal for a low-frequency axion search in the 1-2 $\mu$eV range and below with the BabyIAXO magnet

    S. Ahyoune🇪🇸 · A. Álvarez Melcón🇪🇸 · S. Arguedas Cuendis🇪🇸 · S. Calatroni🇨🇭 · C. Cogollos🇩🇪 · J. Devlin🇬🇧 · A. Díaz-Morcillo🇪🇸 · D. Díez-Ibáñez🇪🇸 · B. Döbrich🇩🇪 · J. Galindo🇪🇸 · J.D. Gallego🇺🇸 · J.M. García-Barceló🇪🇸 and 18 other authors

    In the near future BabyIAXO will be the most powerful axion helioscope, relying on a custom-made magnet of two bores of 70 cm diameter and 10 m long, with a total available magnetic volume of more than 7 m${}^3$. In this document, we propose and describe the implementation of low-frequency axion haloscope setups suitable for operation inside the BabyIAXO magnet. The RADES proposal has a potential sensitivity to the axion-photon coupling $g_{a\gamma }$ down to values corresponding to the KSVZ model, in the (currently unexplored) mass range between 1 and 2$\mu$eV, after a total effective exposure of 440 days. This mass range is covered by the use of four differently dimensioned 5-meter-long cavities, equipped with a tuning mechanism based on inner turning plates. A setup like the one proposed would also allow an exploration of the same mass range for hidden photons coupled to photons. An additional complementary apparatus is proposed using LC circuits and exploring the low energy range ($\sim 10^{-4}-10^{-1}\mu$eV). The setup includes a cryostat and cooling system to cool down the BabyIAXO bore down to about 5 K, as well as appropriate low-noise signal amplification and detection chain.

    ↳ physics.ins-dethep-phAnnalen Phys.(2023)·47 citations
21. 21*

    Generic initial data for binary boson stars

    Nils Siemonsen🇨🇦 · William E. East🇨🇦

    Binary boson stars can be used to model the nonlinear dynamics and gravitational wave signals of merging ultracompact, but horizonless, objects. However, doing so requires initial data satisfying the Hamiltonian and momentum constraints of the Einstein equations, something that has not yet been addressed. In this work, we construct constraint-satisfying initial data for a variety of binary boson star configurations. We do this using the conformal thin-sandwich formulation of the constraint equations, together with a specific choice for the matter terms appropriate for scalar fields. The free data is chosen based upon a superposition of isolated boson star solutions, but with several modifications designed to suppress the spurious oscillations in the stars that such an approach can lead to. We show that the standard approach to reducing orbital eccentricity can be applied to construct quasi-circular binary boson star initial data, reducing the eccentricity of selected binaries to the $\sim 10^{-3}$ level. Using these methods, we construct initial data for quasi-circular binaries with different mass-ratios and spins, including a configuration where the spin is misaligned with the orbital angular momentum, and where the dimensionless spins of the boson stars exceeds the Kerr bound. We evolve these to produce the first such inspiral-merger-ringdown gravitational waveforms for constraint-satisfying binary boson stars. Finally, we comment on how equilibrium equations for the scalar matter could be used to improve the construction of binary initial data, analogous to the approach used for quasi-equilibrium binary neutron stars.

    ↳ gr-qchep-phPRD(2023)·30 citations
22. 22*

    Comparison between holographic deformed AdS and soft wall models for fermions

    Ayrton da Cruz Pereira do Nascimento🇧🇷 · Henrique Boschi-Filho🇧🇷

    We compare the holographic dressed soft wall and the exponentially deformed AdS models for spin 1/2 fermions. We present the dressed soft wall model and its analytical solutions for the left and right modes, and the corresponding spectra, also including modifications considering hyperfine spin-spin and meson cloud interactions, as well as anomalous dimensions. Then, we discuss the deformed AdS model for spin 1/2 fermions and present their effective Schrödinger equations for the left and right modes, for which only numerical solutions are available. Then, we consider a polynomial expansion of the effective potential of the deformed AdS model and show that in the quadratic approximation it leads to exact analytical solutions comparable with the dressed soft wall model and obtain the corresponding spectra for left and right modes. We show a numerical comparison of the mass spectra of spin 1/2 baryons for the dressed soft wall and the deformed AdS models. We present a detailed relation between the quadratic approximation of the deformed AdS and the dressed soft wall models for their spectra, wave functions and comments on the deep inelastic scattering on both models. We find that these two models are {\sl not} equivalent even in the quadratic approximation, but it is possible to relate their left and right modes for particular choices of their parameters.

    ↳ hep-thhep-phPRD(2023)·2 citations
23. 23*

    Calorons, monopoles and stable, charged solitons

    Manfried Faber🇦🇹

    We discuss the similarity of the constituent monopoles of calorons and stable topological solitons with long range Coulombic interaction, classical solutions of the model of topological particles. In the interpretation as electric charges they can be compared to electrons and positrons with spin up and down, with quantised charge and finite mass.

    ↳ hep-lathep-phEPJ Web Conf.(2022)·0 citations
24. 24*

    Large-Scale Atom Interferometry for Fundamental Physics

    Oliver Buchmueller🇬🇧 · John Ellis🇬🇧 · Ulrich Schneider🇬🇧

    Atom interferometers measure quantum interference patterns in the wave functions of cold atoms that follow superpositions of different space-time trajectories. These can be sensitive to phase shifts induced by fundamental physics processes such as interactions with ultralight dark matter or the passage of gravitational waves. The capabilities of large-scale atom interferometers are illustrated by their estimated sensitivities to the possible interactions of ultralight dark matter with electrons and photons, and to gravitational waves in the frequency range around 1 Hz, intermediate between the peak sensitivities of the LIGO and LISA experiments. Atom interferometers can probe ultralight scalar couplings with much greater sensitivity than is currently available from probes of the Equivalence Principle. Their sensitivity to mid-frequency gravitational waves may open a window on mergers of masses intermediate between those discovered by the LIGO and Virgo experiments and the supermassive black holes present in the cores of galaxies, as well as fundamental physics processes in the early Universe such as first-order phase transitions and the evolution of networks of cosmic strings.

    ↳ astro-ph.COgr-qchep-exhep-ph+1Contemp.Phys.(2023)·34 citations
25. 25*

    Yukawa theory in non-perturbative regimes: towards confinement, exact $\beta$-function and conformal phase

    Marco Frasca🇮🇹 · Anish Ghoshal🇵🇱

    We study possible hints towards confinement in a Z${}_2$-invariant Yukawa system with massless fermions and a real scalar field in the strongly-coupled regime. Using the tools developed for studying non-perturbative physics via Jacobi elliptical functions, for a given but not unique choice of the vacuum state, we find the exact Green's function for the scalar sector so that, after integrating out the scalar degrees of freedom, we are able to recover the low-energy limit of the theory that is a fully non-local Nambu-Jona-Lasinio (NJL) model. We provide an analytical result for the Renormalization Group (RG) running of the self-interaction coupling in the scalar sector and critical indexes in the strongly-coupled regime. In the fermion sector, we provide some clues towards confinement, after deriving the gap equation with the non-local NJL model, a property which is well-known to not emerge in the local limit of this model. We conclude that, for the scalar-Yukawa theory in the non-perturbative domain with our choice of the vacuum state, the fundamental fermions of the theory form bound states and cannot be observed as asymptotic states.

    ↳ hep-thhep-phEPJC(2024)·6 citations
26. 26*

    Binary Supermassive Black Holes Orbiting Dark Matter Solitons: From the Dual AGN in UGC4211 to NanoHertz Gravitational Waves

    Tom Broadhurst🇪🇸 · Chao Chen🇨🇳 · Tao Liu🇨🇳 · Kai-Feng Zheng🇨🇳

    We explore orbital implications of the Supermassive Black Hole (SMBH) binary in UGC4211 for the energy spectrum of stochastic gravitational wave background (SGWB), measured with pulsar timing. The SMBH binary in UGC4211 has a projected separation of $\sim 230$pc and relative velocity of $\sim 150$km/s along the line of sight. It orbits with a disk of gas and stars, with a total mass $\sim 1.7\times 10^9{M}_{\odot }$ that is several times larger than the combined SMBHs plus the observed gas and stars. The unseen mass can be naturally explained by a soliton of wave dark matter present within the SMBH orbit. Such a scenario is encouraging as during galaxy merger, the two precursor galactic solitons are expected to combine to generate a new soliton and hence bind the two initial SMBHs efficiently. Generalizing this scenario to the cosmological population of SMBH binaries, we show the SGWB spectrum produced by late-stage inspiraling is modified preferentially at low frequency by the presence of soliton. Finally, we demonstrate that the NANOGrav and EPTA data can be well-fit in this scenario, favoring $\{m_a,f_a\}\sim \{10^{-21.7}\mathrm{eV},10^{15.5}\mathrm{GeV}\}$ and $\{10^{-20.5}\mathrm{eV},10^{16.8}\mathrm{GeV}\}$ respectively when the UGC4211 data and the constraints from dwarf galaxies are also combined.

    ↳ astro-ph.HEastro-ph.COgr-qchep-ph36 citations
27. 27*

    Limits on scalar-induced gravitational waves from the stochastic background by pulsar timing array observations

    Yi-Fu Cai🇨🇳 · Xin-Chen He🇨🇳 · Xiao-Han Ma🇨🇳 · Sheng-Feng Yan🇨🇳 · Guan-Wen Yuan🇨🇳

    Recently, the NANOGrav, PPTA, EPTA, and CPTA collaborations independently reported their evidence of the Stochastic Gravitational Waves Background (SGWB). While the inferred gravitational-wave background amplitude and spectrum are consistent with astrophysical expectations for a signal from the population of supermassive black-hole binaries (SMBHBs), the search for new physics remains plausible in this observational window. In this work, we explore the possibility of explaining such a signal by the scalar-induced gravitational waves (IGWs) in the very early universe. We use a parameterized broken power-law function as a general description of the energy spectrum of the SGWB and fit it to the new results of NANOGrav, PPTA and EPTA. We find that this approach can put constraints on the parameters of IGW energy spectrum and further yield restrictions on various inflation models that may produce primordial black holes (PBHs) in the early universe, which is also expected to be examined by the forthcoming space-based GW experiments.

    ↳ gr-qcastro-ph.COastro-ph.GAastro-ph.HE+1Sci.Bull.(2023)·141 citations
28. 28*

    Effect of interparticle fields and radiation reaction on beam dynamics

    Michael J. Quin · Antonino Di Piazza🇩🇪 · Christoph H. Keitel🇩🇪 · Matteo Tamburini🇩🇪

    The dynamics of relativistic particles in an intense electromagnetic field can be described by the Landau-Lifshitz (LL) equation, where the adiation reaction (RR) is accounted for via a self-force, and interparticle fields are often neglected as an approximation. However, the inclusion of interparticle fields is necessary to ensure energy-momentum conservation, particularly during coherent emission. Here we present (i) an analytical proof showing that the energy-momentum conservation law of the Hamilton-Rohrlich-Dirac action, which is divergence free and describes a generic system of interacting charges, respects causality and provides physically sensible results; (ii) a simple generalization of the LL equation for many particles evaluated as a function of the total field, i.e., the sum of the external and interparticle fields. By performing first-principles numerical simulations of a neutral, relativistic bunch of electrons and positrons ($e^{-}/e^{+}$) colliding with a laser pulse, this theory is shown to satisfy energy-momentum conservation when interparticle fields and RR are simultaneously taken into account; and (iii) the combined effect of interparticle fields and RR primarily affects the tail of the particle energy distribution. Additionally, our first-principles simulations show that the effect of interparticle fields on beam energy loss becomes smaller when most of the radiated energy is incoherent.

    ↳ physics.plasm-phhep-phphysics.class-phPRResearch(2025)·5 citations
29. 29*

    The Detected Stochastic Gravitational Waves and Subsolar-Mass Primordial Black Holes

    Keisuke Inomata🇺🇸 · Kazunori Kohri🇯🇵 · Takahiro Terada🇰🇷

    Multiple pulsar timing array (PTA) collaborations recently announced the evidence of common-spectral processes caused by gravitational waves (GWs). These can be the stochastic GW background and its origin may be astrophysical and/or cosmological. We interpret it as the GWs induced by the primordial curvature perturbations and discuss their implications on primordial black holes (PBHs). We show that the newly released data suggest PBHs much lighter than the Sun ($\mathcal{O}(10^{-4})M_{\odot }$ for the delta-function curvature spectrum; $<\mathcal{O}(10^{-2})M_{\odot }$ more generally) in contrast to what was expected from the previous PTA data releases.

    ↳ astro-ph.COgr-qchep-phPRD(2024)·141 citations
30. 30*

    Signals of merging supermassive primordial black holes in pulsar timing arrays

    Paul Frederik Depta🇩🇪 · Kai Schmidt-Hoberg🇩🇪 · Pedro Schwaller🇩🇪 · Carlo Tasillo🇩🇪

    In this work we evaluate whether the gravitational wave background recently observed by a number of different pulsar timing arrays could be due to merging primordial supermassive black hole binaries. We find that for homogeneously distributed primordial black holes this possibility is inconsistent with strong cosmological and astrophysical constraints on their total abundance. If the distribution exhibits some clustering, however, the merger rate will, in general, be enhanced, opening the window for a consistent interpretation of the pulsar timing array data in terms of merging primordial black holes, if $\mu$-distortion constraints associated with the formation mechanism can be evaded.

    ↳ astro-ph.COhep-phPRResearch(2025)·65 citations
31. 31*

    Domain wall interpretation of the PTA signal confronting black hole overproduction

    Yann Gouttenoire🇮🇱 · Edoardo Vitagliano🇮🇱

    Recently, Pulsar Timing Array (PTA) collaborations have detected a stochastic gravitational wave background (SGWB) at nano-Hz frequencies, with Domain Wall networks (DWs) proposed as potential sources. To be cosmologically viable, they must annihilate before dominating the universe energy budget, thus generating a SGWB. While sub-horizon DWs shrink and decay rapidly, causality requires DWs with super-horizon size to continue growing until they reach the Hubble horizon. Those entering the latest can be heavier than a Hubble patch and collapse into Primordial Black Holes (PBHs). We conduct a Bayesian analysis of the PTA signal, interpreting it as an outcome of SGWB from DW networks, with a prior ensuring no PBH overproduction. Our findings indicate that DWs result in the production of solar-mass PBHs. The binary mergers occurring within these PBHs generate a second SGWB in the kilo-Hz domain which could be observable in on-going or planned Earth-based interferometers.

    ↳ gr-qcastro-ph.COhep-phhep-thPRD(2024)·103 citations
32. 32*

    Probing The Longest Dark Matter Lifetimes with the Line Emission Mapper

    Gordan Krnjaic🇺🇸 · Elena Pinetti🇺🇸

    In the next decade, the proposed Line Emission Mapper (LEM) telescope concept is poised to revolutionize Galactic and extragalactic X-ray sensitivity. The instruments aboard LEM feature unprecedented eV scale energy resolution and an effective area of 1600 cm${}^2$ at 0.5 keV. Such features are ideally suited to explore decaying dark matter candidates that predict X-ray signals, including axion-like particles and sterile neutrinos. We present the first forecast of LEM sensitivity to dark matter decays and find sensitivity to lifetimes beyond $\sim 10^{32}$ s in the keV range, surpassing current limits by several orders of magnitude. Notably, our results show that LEM will be the first ever instrument to probe such long dark matter lifetimes in any mass range for any decay channel.

    ↳ astro-ph.COastro-ph.GAastro-ph.HEhep-phPRD(2024)·5 citations
33. 33*

    Simple Hamiltonian for Quantum Simulation of Strongly Coupled 2+1D SU(2) Lattice Gauge Theory on a Honeycomb Lattice

    Berndt Müller🇺🇸 · Xiaojun Yao🇺🇸

    We find a simple spin Hamiltonian to describe physical states of $2+1$ dimensional SU(2) lattice gauge theory on a honeycomb lattice with a truncation of the electric field representation at $j_{\max }=\frac{1}{2}$. The simple spin Hamiltonian only contains local products of Pauli matrices, even though Gauss's law has been completely integrated out.

    ↳ quant-phhep-lathep-phnucl-thPRD(2023)·42 citations
34. 34*

    Gravitational wave sources for Pulsar Timing Arrays

    Ligong Bian🇨🇳 · Shuailiang Ge🇨🇳 · Jing Shu🇨🇳 · Bo Wang🇨🇳 · Xing-Yu Yang🇰🇷 · Junchao Zong🇨🇳

    Very recently, several pulsar timing array collaborations, including CPTA, EPTA, and NANOGrav, reported their results from searches for an isotropic stochastic gravitational wave background (SGWB), with each finding positive evidence for SGWB. In this work, we assessed the credibility of interpreting the Hellings-Downs correlated free-spectrum process of EPTA, PPTA, and NANOGrav as either the result of supermassive black hole binary mergers or various stochastic SGWB sources that originated in the early Universe, including first-order phase transitions, cosmic strings, domain walls, and large-amplitude curvature perturbations. Our observations show that the current new datasets do not display a strong preference for any specific SGWB source based on Bayesian analysis.

    ↳ astro-ph.HEastro-ph.COgr-qchep-ph+1PRD(2024)·90 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.