Tue·May 23, 2023Tuesday·May 23, 2023

1. 01*

   Final-state interactions in the CP asymmetries of charm-meson two-body decays

   Antonio Pich🇪🇸 · Eleftheria Solomonidi🇪🇸 · Luiz Vale Silva🇪🇸

   Urgent theoretical progress is needed in order to provide an estimate in the Standard Model of the recent measurement by LHCb of direct CP violation in charm-meson two-body decays. Rescattering effects must be taken into account for a meaningful theoretical description of the amplitudes involved in such category of observables, as signaled by the presence of large strong phases. We discuss the computation of the latter effects based on a two-channel coupled dispersion relation, which exploits isospin-zero phase-shifts and inelasticity parameterizations of data coming from the rescattering processes $\pi \pi \to \pi \pi$, $\pi K\to \pi K$, and $\pi \pi \to K\overline{K}$. The determination of the subtraction constants of the dispersive integrals relies on the leading contributions to the transition amplitudes from the $1/N_C$ counting, where $N_C$ is the number of QCD colours. Furthermore, we use the measured values of the branching ratios to help in selecting the non-perturbative inputs in the isospin limit, from which we predict values for the CP asymmetries. We find that the predicted level of CP violation is much below the experimental value.

   hep-phPRD(2023)·46 citations
2. 02*

   Running effects on QCD axion phenomenology

   Luca Di Luzio🇮🇹 · Maurizio Giannotti🇺🇸 · Federico Mescia🇪🇸 · Enrico Nardi🇮🇹 · Shohei Okawa🇪🇸 · Gioacchino Piazza🇫🇷

   We study the impact of renormalization group effects on QCD axion phenomenology. Focusing on the DFSZ model, we argue that the relevance of running effects for the axion couplings crucially depends on the scale where the heavier Higgs scalars are integrated out. We study the impact of these effects on astrophysical and cosmological bounds as well as on the sensitivity of helioscopes experiments such as IAXO and XENONnT, showing that they can be sizable even in the most conservative case in which the two Higgs doublets remain as light as the TeV scale. We provide simple analytical expressions that accurately fit the numerical solutions of the renormalization group equations as a function of the mass scale of the heavy scalars.

   hep-phastro-ph.COastro-ph.HEPRD(2023)·20 citations
3. 03*

   Fermion mass hierarchy in an extended left-right symmetric model

   Cesar Bonilla🇨🇱 · A. E. Cárcamo Hernández🇨🇱 · Sergey Kovalenko🇨🇱 · H. Lee🇫🇷 · R. Pasechnik🇸🇪 · Ivan Schmidt🇨🇱

   We present a Left-Right symmetric model that provides an explanation for the mass hierarchy of the charged fermions within the framework of the Standard Model. This explanation is achieved through the utilization of both tree-level and radiative seesaw mechanisms. In this model, the tiny masses of the light active neutrinos are generated via a three-loop radiative inverse seesaw mechanism, with Dirac and Majorana submatrices arising at one-loop level. To the best of our knowledge, this is the first example of the inverse seesaw mechanism being implemented with both submatrices generated at one-loop level. The model contains a global $U(1{)}_X$ symmetry which, after its spontaneous breaking, allows for the stabilization of the Dark Matter (DM) candidates. We show that the electroweak precision observables, the electron and muon anomalous magnetic moments as well as the Charged Lepton Flavor Violating decays, $\mu \to e\gamma$, are consistent with the current experimental limits. In addition, we analyze the implications of the model for the $95$ GeV diphoton excess recently reported by the CMS collaboration and demonstrate that such anomaly could be easily accommodated. Finally, we discuss qualitative aspects of DM in the considered model.

   hep-phJHEP(2023)·38 citations
4. 04*

   Number density interpretation of dihadron fragmentation functions

   D. Pitonyak🇺🇸 · C. Cocuzza🇺🇸 · A. Metz🇺🇸 · A. Prokudin🇺🇸 · N. Sato🇺🇸

   We present a new quantum field-theoretic definition of fully unintegrated dihadron fragmentation functions (DiFFs) as well as a generalized version for $n$-hadron fragmentation functions. We demonstrate that this definition allows certain sum rules to be satisfied, making it consistent with a number density interpretation. Moreover, we show how our corresponding so-called extended DiFFs that enter existing phenomenological studies are number densities and also derive their evolution equations. Within this new framework, DiFFs extracted from experimental measurements will have a clear physical meaning.

   hep-phhep-exnucl-thPRL(2024)·38 citations
5. 05*

   High energy bremsstrahlung at the FCC-ee, FCC-eh and LHeC

   Krzysztof Piotrzkowski🇵🇱 · Mariusz Przybycien🇵🇱

   Bremsstrahlung spectra will be strongly distorted due to small lateral beam sizes at future colliders. That in turn will have large consequences for the electron and positron beam lifetimes as well as for the luminosity measurements in the case of electron-hadron colliders. We discuss in detail such consequences for the Future Circular Collider and Large Hadron electron Collider cases.

   hep-phhep-exEPJC(2023)·2 citations
6. 06*

   Leveraging on-shell interference to search for FCNCs of the top quark and the Z boson

   Lucas Cremer🇩🇪 · Johannes Erdmann🇩🇪 · Roni Harnik🇺🇸 · Jan Lukas Späh🇩🇪 · Emmanuel Stamou🇩🇪

   Flavour-changing-neutral currents (FCNCs) involving the top quark are highly suppressed within the Standard Model (SM). Hence, any signal in current or planned future collider experiments would constitute a clear manifestation of physics beyond the SM. We propose a novel, interference-based strategy to search for top-quark FCNCs involving the $Z$ boson that has the potential to complement traditional search strategies due to a more favourable luminosity scaling. The strategy leverages on-shell interference between the FCNC and SM decay of the top quark into hadronic final states. We estimate the feasibility of the most promising case of anomalous $tZc$ couplings using Monte Carlo simulations and a simplified detector simulation. We consider the main background processes and discriminate the signal from the background with a deep neural network that is parametrised in the value of the anomalous $tZc$ coupling. We present sensitivity projections for the HL-LHC and the FCC-hh. We find an expected $95\%$ CL upper limit of ${\mathcal{B}}_{\mathrm{excl}}(t\to Zc)=6.4\times 10^{-5}$ for the HL-LHC. In general, we conclude that the interference-based approach has the potential to provide both competitive and complementary constraints to traditional multi-lepton searches and other strategies that have been proposed to search for $tZc$ FCNCs.

   hep-phhep-exEPJC(2023)·8 citations
7. 07*

   Quantum coherence and entanglement in neutral-current neutrino oscillation in matter

   M.M. Ettefaghi🇮🇷 · Z. Askaripour Ravari🇮🇷

   Although neutrino-antineutrino states originating from neutral-current interactions are blind concerning the flavor state, an oscillation pattern is predicted provided that both neutrino and antineutrino are detected. This issue arises from both the coherence and entanglement of the neutrino-antineutrino states. Based on quantum resource theory, we use the l1-norm and concurrence to quantify quantum coherence and entanglement, respectively. Considering the localization properties by the wave packet approach and a matter potential which appears when neutrino and antineutrino propagate in a material medium, we obtain the l1-norm and concurrence. We see that the neutrino and antineutrino remain entangled for larger baseline lengths when they propagate in a material medium. In the case of the coherence property, the l1-norm decreases in comparison to the corresponding one in vacuum. However, its damping occurs for larger distances.

   hep-phEPJC(2023)·12 citations
8. 08*

   Visualization and Efficient Generation of Constrained High-dimensional Theoretical Parameter Spaces

   Jason Baretz🇺🇸 · Nicholas Carrara🇺🇸 · Jacob Hollingsworth🇺🇸 · Daniel Whiteson🇺🇸

   We describe a set of novel methods for efficiently sampling high-dimensional parameter spaces of physical theories defined at high energies, but constrained by experimental measurements made at lower energies. Often, theoretical models such as supersymmetry are defined by many parameters, $\mathcal{O}(10-100)$, expressed at high energies, while relevant experimental constraints are often defined at much lower energies, preventing them from directly ruling out portions of the space. Instead, the low-energy constraints define a complex, potentially non-contiguous subspace of the theory parameters. Naive scanning of the theory space for points which satisfy the low-energy constraints is hopelessly inefficient due to the high dimensionality, and the inverse problem is considered intractable. As a result, many theoretical spaces remain under-explored. We introduce a class of modified generative autoencoders, which attack this problem by mapping the high-dimensional parameter space to a structured low-dimensional latent space, allowing for easy visualization and efficient generation of theory points which satisfy experimental constraints. An extension without dimensional compression, which focuses on limiting potential information loss, is also introduced.

   hep-phhep-thJHEP(2023)·6 citations
9. 09*

   Electric current from Schwinger's time-ordered propagator

   Cristian Villavicencio🇨🇱

   The quasistatic electric current density of fermions in the presence of an external electric field is determined through the utilization of a time-ordered Schwinger propagator. The study encompasses the necessary conditions for establishing a well-defined time-ordered propagator within the Schwinger formalism, specifically concentrating on constant and uniform electromagnetic fields. Within this theoretical framework, a chemical potential is introduced, resulting in non-zero values for the electric current and charge number density. Consequently, the dependence of electric conductivity on the strength of the electric field and the charge number density is investigated.

   hep-phnucl-thRev.Mex.Fis.(2026)·1 citation
10. 10*

    Dusty Dark Matter Bubbles of a New Vacuum stopped in Earth and Radiating 3.5 keV X-rays

    Holger Bech Nielsen🇩🇰 · Colin D. Froggatt🇬🇧

    We continue our work on a proposal for what dark matter could be, namely that the dark matter consists of essentially macroscopic objects built from ordinary matter. The only element of new physics is that there should exist several types or phases of vacuum. Then the dark matter particles are bubbles of a new type of vacuum filled with ordinary matter - say diamond - under high pressure and the whole bubble is supposedly contaminated by the materials in the extra galactic or intragalactic space able to form dust. The dust has a lower than dimension 3 structure and may well be long chains of atoms. We begin speculations on identifying the phase transition between the vacua, which we require in our model, with a (second order?) transition revealed in the Columbia plot with quark masses as axes. In the corner of small quark masses there is a true phase transition as temperature is raised, while outside this region there is instead no genuine phase transition under variation of the temperature but rather only a crossover.

    hep-phastro-ph.COastro-ph.HEPoS(2023)·4 citations
11. 11*

    Lorentz violation in $\gamma$-pair production ($e^{+}{e}^{-}\to \gamma \gamma$)

    Alessio T. B. Celeste🇧🇷 · Adriano M. Santos🇧🇷

    This paper specifically focuses on the choice of a temporal background field over a spatial one in the context of Lorentz symmetry breaking. By examining the implications of this choice, we aim to understand the effects of Lorentz violation in different scenarios, with an emphasis on the consequences of adopting a purely temporal background field. In the analysis of $\gamma$-pair production, a brief approach in QED is presented, exploring the production of a pair of photons. Furthermore, the study investigates Lorentz violation with vectorial nonminimal coupling, analyzing the modifications introduced by this coupling in the scattering amplitude at the vertex. Additionally, Lorentz violation with axial-like nonminimal coupling is explored, with a particular focus. The additional coupling introduces further modifications to the scattering amplitude, highlighting the intricate nature of Lorentz symmetry breaking in different scenarios.

    hep-phhep-thJ.Phys.G(2024)·3 citations
12. 12*

    aNNLO results for $t\bar{t}\gamma$ cross sections

    Nikolaos Kidonakis🇺🇸 · Alberto Tonero🇺🇸

    We present theoretical calculations of total cross sections and top-quark transverse-momentum and rapidity distributions in the associated production of a top-antitop pair with a photon ($t\bar{t}\gamma$ production). We include complete QCD and electroweak corrections at NLO as well as soft-gluon corrections at approximate NNLO (aNNLO). The aNNLO corrections are very significant, they decrease theoretical uncertainties, and they are needed for better comparison with data from the LHC.

    hep-ph1 citation
13. 13*

    Inverse magnetic catalysis and energy loss in holographic QCD model

    Zhou-Run Zhu🇨🇳 · Defu Hou🇨🇳

    In this paper, we consider the Einstein-Maxwell-dilaton holographic model for light quarks with nonzero magnetic field and chemical potential. First, we study the phase diagrams in $T-\mu$ and $T-B$ planes. We observe inverse magnetic catalysis which is consistent with the lattice QCD results. We discuss the influence of the magnetic field and chemical potential on the location of the critical end point (CEP). It is found that the magnetic field increases the critical ${\mu }_{CEP}$ of the CEP in the $T-\mu$ plane and the chemical potential increases the critical $B_{CEP}$ of the CEP in the $T-B$ plane. Second, we discuss the equations of state (EOS) with nonzero magnetic field and chemical potential. We observe that the EOS near the phase transition temperature are nonmonotonic. Then we study the energy loss with a nonzero magnetic field and chemical potential. It is found that the drag force of the heavy quark and jet quenching parameter $\hat{q}$ show an enhancement near the phase transition temperature. The peak values of drag force and $\hat{q}$ are pushed toward lower temperature with increasing $B$ or $\mu$. This phenomenon is consistent with the phase transition temperature decrease with increasing $B$ or $\mu$ in this holographic model. Moreover, we find that the heavy quark may lose more energy when it is perpendicular to a magnetic field which is consistent with the results of the jet quenching parameter.

    hep-phPRD(2024)·18 citations
14. 14*

    Neutrino Mass Matrix in Neutrino-Related Processes

    M. I. Krivoruchenko🇷🇺 · F. Simkovic🇸🇰

    Techniques are developed for constructing amplitudes of neutrino-related processes in terms of the neutrino mass matrix, with no reference to the neutrino mixing matrix. The amplitudes of neutrino oscillations in vacuum and medium, quasi-elastic neutrino scattering, $\beta$ decays and double-$\beta$ decays are considered. The proposed approach makes extensive use of Frobenius covariants within the framework of Sylvester's theorem on matrix functions. The in-medium dispersion laws are found in terms of elementary functions for three flavors of Majorana neutrinos as an application of the developed formalism. The in-medium dispersion laws for Dirac neutrinos can be determined in the general case by searching for the roots of a polynomial of degree 6. In the rest frame of baryon matter, the minimum energy of both Majorana and Dirac neutrinos is achieved at a finite neutrino momentum. In such cases, Dirac neutrinos occupy a hollow Fermi sphere at zero temperature and low densities. Fitting experimental data in terms of the neutrino mass matrix can provide better statistical accuracy in determining the neutrino mass matrix compared to methods using the neutrino mixing matrix at intermediate stages.

    hep-phPhys.Atom.Nucl.(2023)·4 citations
15. 15*

    On the momentum broadening of in-medium jet evolution using a light-front Hamiltonian approach

    Meijian Li🇪🇸 · Tuomas Lappi🇫🇮 · Xingbo Zhao🇨🇳 · Carlos A. Salgado🇪🇸

    Following the non-perturbative light-front Hamiltonian formalism developed in our preceding work [Phys.Rev.D 104 (2021) 5, 056014], we investigate the momentum broadening of a quark jet inside a SU(3) colored medium. We perform the numerical simulation of the real-time jet evolution in Fock spaces of a single quark, a quark-gluon state, and coupled quark- and quark-gluon states at various jet momenta $p^{+}$ and medium densities. With the obtained jet light-front wavefunction, we extract the jet transverse momentum distribution, the quenching parameter, and the gluon emission rate. We analyze the dependence of momentum broadening on $p^{+}$, medium density, color configuration, spatial correlation, and medium-induced gluon emission. For comparison, we also derive analytically the expectation value of the transverse momentum of a quark-gluon state in any color configuration and in an arbitrary spatial distribution in the eikonal limit. This work can help understand jet momentum broadening in the non-eikonal regime.

    hep-phnucl-thPRD(2023)·21 citations
16. 16*

    Exploring the $0^{-}$ bound state with dressed quarks in Minkowski space

    A. Castro · W. de Paula · E. Ydrefors · T. Frederico · G. Salme

    The Bethe-Salpeter equation for a pseudoscalar bound-system, with i) a ladder kernel with massive gluons, ii) dynamically-dressed quark mass function and iii) an extended quark-gluon vertex, is solved in Minkowski space by using the Nakanishi integral representation of the Bethe-Salpeter amplitude. The quark dressing is implemented through a phenomenological ansatz, which was tuned by lattice QCD calculations of the quark running mass. The latter were also used for assigning the range of the gluon mass and the parameter featuring the extended color density. This framework allows to investigate the gluon dynamics that manifest itself in the quark dressing, quark-gluon vertex and the binding, directly in the physical space. We present the first results for low-density pseudoscalar systems in order to elucidate the onset of the interplay between the above mentioned gluonic phenomena, and we discuss both static and dynamical quantities, like valence longitudinal and transverse distributions.

    hep-phhep-thnucl-thPLB(2023)·9 citations
17. 17*

    Testing Unification and Dark Matter with Gravitational Waves

    Bartosz Fornal🇺🇸 · Kassandra Garcia🇺🇸 · Erika Pierre🇺🇸

    We propose to search for a new type of gravitational wave signature relevant for particle physics models with symmetries broken at vastly different energy scales. The spectrum contains a characteristic double-peak structure consisting of a sharp peak from domain walls and a smooth bump from a first order phase transition in the early Universe. We demonstrate how such a gravitational wave signal arises in a new theory unifying baryon number and color into an SU(4) gauge group broken at the multi-TeV scale, and with lepton number promoted to an SU(2) gauge symmetry broken at the multi-EeV scale. The model contains two types of dark matter particles, explains the observed domination of matter over antimatter in the Universe, and accommodates nonzero neutrino masses. We discuss how future gravitational wave experiments, such as LISA, Big Bang Observer, DECIGO, Einstein Telescope, and Cosmic Explorer, can be utilized to look for this novel signature.

    hep-phgr-qcPRD(2023)·11 citations
18. 18*

    Direct detection of cosmic ray-boosted puffy dark matter

    Wenyu Wang🇨🇳 · Wu-Long Xu🇨🇳 · Jin Min Yang🇨🇳 · Rui Zhu🇨🇳

    For the light relativistic dark matter (DM) boosted by high energy cosmic ray, its scattering cross section with the nucleon is sensitively dependent on the momentum-transfer and such an dependence is caused by the mediator in the scattering. For puffy DM particle with a size, the momentum-transfer dependence can also arise from the DM radius effect. All these momentum-transfer dependences should be considered. In this note we study the direct detection limits on the cosmic ray-boosted puffy DM for a simplified model with a light mediator. For comparison, we first re-derive the direct detection limits on the cosmic ray-boosted point-like DM. We display the limits on various planes of parameters and find that the limits for the cosmic ray-boosted puffy DM are stronger than for the point-like DM.

    hep-phastro-ph.COhep-exNPB(2023)·21 citations
19. 19*

    Quark distribution functions and spin-flavor structures in $N\to \Delta$ transitions

    June-Young Kim🇺🇸

    Transition generalized parton distributions have emerged as a novel tool for studying the quantum chromodynamics (QCD) structure of resonances. They provide an integrated picture of the transition form factors and the transition parton distribution functions. In this study, we delve into the angular momentum (AM) properties for the $N\to \Delta$ transition and its decomposition into the orbital angular momentum and the intrinsic spin in the context of the quark distribution functions. First, we explore the spin-flavor structures within the framework of both the overlap representations of the three-quark light-cone wave functions and the large $N_c$ limit of QCD. We then estimate the AM quark distribution functions for the $N\to \Delta$ transition. Our analysis reveals a substantial flavor asymmetry present in both the orbital angular momentum and intrinsic spin components.

    hep-phhep-latPRD(2023)·14 citations
20. 20*

    Global Symmetries and Effective Potential of 2HDM in Orbit Space

    Qing-Hong Cao🇨🇳 · Kun Cheng🇨🇳 · Changlong Xu🇨🇳

    We extend the framework of analyzing the 2HDM in its orbit space to study the one-loop effective potential before and after electroweak symmetry breaking. In this framework, we present a comprehensive analysis of global symmetries of the one-loop thermal effective potential in the 2HDM, demonstrating when the global symmetries of the tree-level 2HDM potential are broken by loop contributions. By introducing light-cone coordinates and generalizing the bilinear notation around the vacuum, we present a geometric view of the scalar mass matrix and on-shell renormalization conditions.

    hep-phhep-exPRD(2023)·9 citations
21. 21*

    Precision test of the muon-Higgs coupling at a high-energy muon collider

    Jürgen Reuter🇩🇪

    Muon colliders offer the possibility to go to very high energies with relatively small circular colliders, energies up to 10 or 14 TeV are envisioned. Due to their very clean collider environment they provide a fantastic tool to search for new physics in the electroweak sector, especially through the production of multiple EW vector and Higgs bosons, and they allow to measure the Higgs-muon coupling very precisely. I will elucidate the physics capabilities from these processes and also discuss issues on precision predictions for SM backgrounds at high-energy lepton colliders.

    hep-phPoS(2023)·2 citations
22. 22*

    Non-factorizable virtual corrections to Higgs boson production in weak boson fusion beyond the eikonal approximation

    Ming-Ming Long🇩🇪 · Kirill Melnikov🇩🇪 · Jérémie Quarroz🇩🇪

    Non-factorizable virtual corrections to Higgs boson production in weak boson fusion at next-to-next-to-leading order in QCD were estimated in the eikonal approximation [1]. This approximation corresponds to the expansion of relevant amplitudes around the forward limit. In this paper we compute the leading power correction to the eikonal limit and show that it is proportional to first power of the Higgs boson transverse momentum or the Higgs boson mass over partonic center-of-mass energy. Moreover, this correction can be significantly enhanced by the rapidity of the Higgs boson. For realistic weak boson fusion cuts, the next-to-eikonal correction reduces the estimate of non-factorizable contributions to fiducial cross section by O(30) percent.

    hep-phJHEP(2023)·11 citations
23. 23*

    Simulations of laser-driven strong-field QED with Ptarmigan: Resolving wavelength-scale interference and $\gamma$-ray polarization

    T. G. Blackburn🇸🇪 · B. King🇬🇧 · S. Tang🇨🇳

    Accurate modelling is necessary to support precision experiments investigating strong-field QED phenomena. This modelling is particularly challenging in the transition between the perturbative and nonperturbative regimes, where the normalized laser amplitude $a_0$ is comparable to unity and wavelength-scale interference is significant. Here we describe how to simulate nonlinear Compton scattering, Breit-Wheeler pair creation, and trident pair creation in this regime, using the Monte Carlo particle-tracking code Ptarmigan. This code simulates collisions between high-intensity lasers and beams of electrons or $\gamma$ rays, primarily in the framework of the locally monochromatic approximation (LMA). We benchmark our simulation results against full QED calculations for pulsed plane waves and show that they are accurate at the level of a few per cent, across the full range of particle energies and laser intensities. This work extends our previous results to linearly polarized lasers and arbitrarily polarized $\gamma$ rays.

    hep-phphysics.plasm-phPhys.Plasmas(2023)·40 citations
24. 24*

    Breakup corrections to spin asymmetries in the ${}^3$He beam polarization measurements with the Polarized Atomic Hydrogen Gas Jet Target

    Andrei Poblaguev🇺🇸

    The requirements for hadron polarimetry at the future Electron Ion Collider (EIC) include measurements of the absolute helion (${}^3$He, $h$) beam polarization with systematic uncertainties better than ${\sigma }_P^{\text{syst}}/P\le 1\%$. Recently, it was proposed that the Polarized Atomic Hydrogen Gas Jet Target (HJET) be utilized for the precision measurement of the polarization of the $\approx 100\text{GeV/n}$ helion beam. At the Relativistic Heavy Ion Collider, HJET serves to determine the absolute proton beam polarization with low systematic uncertainties of about ${\delta }^{\text{syst}}P/P\lesssim 0.5\%$. To adapt the HJET method for the EIC helion beam, the experimentally determined ratio of the beam and target (jet) spin-correlated asymmetries should be adjusted by the ratio of $p^{\uparrow }h$ and $h^{\uparrow }p$ analyzing powers. A potential problem with the suggested method is that the breakup of ${}^3$He in polarization measurements could drastically affect the analyzing power ratio. However, an analysis of the breakup corrections, presented in this paper, reveals that while these corrections can be as substantial as $\approx 4\%$, the effect cancels out to a negligible level in the measured beam polarization.

    hep-phPRC(2023)·4 citations
25. 25*

    Chiral magnetic effect in a cylindrical domain

    Matteo Buzzegoli🇺🇸 · Kirill Tuchin🇺🇸

    We compute the chiral magnetic effect (CME) in a cylindrical region coaxial with the external magnetic field. As the boundary condition we require vanishing of the radial component of the electric current on the cylinder side wall. We find that when the magnetic length is comparable to or larger than the cylinder radius, the CME is suppressed compared to the corresponding result in an infinite medium. As a result, for a given cylinder radius, the suppression is stronger in weak fields. We argue that the electric current generated by the CME vanishes at the cylinder wall and monotonically increases toward the symmetry axis.

    hep-phcond-mat.mes-hallhep-thnucl-thPRD(2023)·4 citations
26. 26*

    Production of bottomonia states in proton+proton and heavy-ion collisions

    Vineet Kumar🇮🇳 · Prashant Shukla🇮🇳 · Abhijit Bhattacharyya🇮🇳

    In this work, we review the experimental and theoretical developments of bottomonia production in proton+proton and heavy-ion collisions. The bottomonia production process is proving to be one of the most robust processes to investigate the fundamental aspects of Quantum Chromodynamics at both low and high temperatures. The LHC experiments in the last decade have produced large statistics of bottomonia states in wide kinematic ranges in various collision systems. The bottomonia have three ${\rm Y}$ S-states which are reconstructed in dilepton invariant mass channel with high mass resolution by LHC detectors and P-states are measured via their decay to S-states. We start with the details of measurements in proton+proton collisions and their understanding in terms of various effective theoretical models. Here we cover both the Tevatron and LHC measurements with $\sqrt{s}$ spanning from 1.8 TeV to 13 TeV. The bottomonia states have particularly been very good probes to understand strongly interacting matter produced in heavy-ion collisions. The Pb+Pb collisions have been performed at $\sqrt{s_{NN}}$ = 2.76 TeV and 5.02 TeV at LHC. This led to the detailed study of the modification of bottomonia yields as a function of various observables and collision energy. At the same time, the improved results of bottomonia production became available from RHIC experiments which have proven to be useful for a quantitative comparison. A systematic study of bottomonia production in p+p, p+Pb and Pb+Pb has been very useful to understand the medium effects in these collision systems. We review some of the (if not all the) models of bottomonia evolution due to various processes in a large dynamically evolving medium and discuss these in comparison with the measurements.

    hep-phnucl-exnucl-thPPNP(2023)·3 citations
27. 27*

    Inconsistencies in, and short pathlength correction to, $R_{AA}(p_T)$ in $\mathrm{A}+\mathrm{A}$ and $\mathrm{p}+\mathrm{A}$ collisions

    Coleridge Faraday🇿🇦 · Antonia Grindrod🇿🇦 · W. A. Horowitz🇿🇦

    We present the first leading hadron suppression predictions in $\mathrm{Pb}+\mathrm{Pb}$ and $\mathrm{p}+\mathrm{Pb}$ collisions from a convolved radiative and collisional energy loss model in which partons propagate through a realistic background and in which the inelastic energy loss receives a short pathlength correction. We find that the short pathlength correction is small for $D$ and $B$ meson $R_{AA}(p_T)$ in both $\mathrm{Pb}+\mathrm{Pb}$ and $\mathrm{p}+\mathrm{Pb}$ collisions. However the short pathlength correction leads to a surprisingly large reduction in suppression for $\pi$ mesons in $\mathrm{p}+\mathrm{Pb}$ and even $\mathrm{Pb}+\mathrm{Pb}$ collisions. We systematically check the consistency of the assumptions used in the radiative energy loss derivation - such as collinearity, softness, and large formation time - with the final numerical model. While collinearity and softness are self-consistently satisfied in the final numerics, we find that the large formation time approximation breaks down at modest to high momenta $p_T\gtrsim 30$ GeV. We find that both the size of the small pathlength correction to $R_{AA}(p_T)$ and the $p_T$ at which the large formation time assumption breaks down are acutely sensitive to the chosen distribution of scattering centers in the plasma.

    hep-phnucl-thEPJC(2023)·16 citations
28. 28*

    Conserved charge susceptibilities in the relativistic mean-field hadron resonance gas model: constraints on hadronic repulsive interactions

    Somenath Pal🇮🇳 · Guruprasad Kadam🇮🇳 · Abhijit Bhattacharyya🇮🇳

    We investigate the effect of repulsive interaction between hadrons on the susceptibilities of conserved charges, namely baryon number (B), electric charge (Q) and strangeness (S). We estimate second fourth and sixth-order susceptibilities of conserved charges, their differences, ratios, and correlations within the ambit of the mean-field hadron resonance gas (MFHRG) model. We consider repulsive mean-field interaction among meson pairs, baryon pairs and anti-baryon pairs separately and constrain them by confronting the results of various susceptibilities with the recent lattice QCD (LQCD) data. We find that the repulsive interactions between baryon-baryon pairs and antibaryon-antibaryon pairs are sufficient to describe the baryon susceptibilities of hadronic matter at temperatures below the QCD transition temperature. However, small but finite mesonic repulsive interaction is needed to describe electric charge and strangeness susceptibilities. We finally conclude that the repulsive interaction between hadrons plays a very important role in describing the thermodynamic properties of hadronic matter, especially near the quark-hadron phase transition temperature ($T_c$). The mean-field parameter for baryons ($K_B$) should be constrained in the range $0.40\le K_B\le 0.450$ ${\text{GeV.fm}}^3$ to get a good agreement of baryon susceptibilities with the LQCD results, whereas meson mean-field parameter $K_M\sim 0.05$ ${\text{GeV.fm}}^3$ must be included with $K_B$ to get a reasonable agreement of the MFHRG model with the LQCD results for electric charge and strangeness susceptibilities.

    hep-phnucl-thMod.Phys.Lett.A(2025)·4 citations
29. 29*

    The Multiplicity Scaling of the Fragmentation Function

    Zhong-Bo Kang🇺🇸 · Robert Kao🇺🇸 · Andrew J. Larkoski🇺🇸

    The single-particle inclusive fragmentation function and the particle multiplicity are observables of fundamental importance in studying properties of quantum chromodynamics at colliders. It is well-known that at high energies, the multiplicity distribution satisfies KNO scaling in which all moments are proportional to powers of the mean multiplicity. We prove that, under weak assumptions, the leading dependence of the fragmentation function on multiplicity is itself a kind of KNO scaling in which all moments are inversely proportional to powers of the mean multiplicity. This scaling with multiplicity additionally accounts for the dominant dependence on collision energy in the fragmentation function. The proof relies crucially on properties of the fragmentation function conditioned on the total multiplicity and application of the Stieltjes moment problem. In the process, we construct a novel basis of the fragmentation function expressed as an overall exponential suppression times a series of Laguerre polynomials. We study this scaling of the fragmentation function in experimental electron-position collision data and observe that residual scale violations are significantly reduced.

    hep-phhep-exnucl-exnucl-thPRD(2024)·4 citations
30. 30*

    Baryon asymmetry from dark matter decay

    Debasish Borah🇮🇳 · Suruj Jyoti Das🇮🇳 · Rishav Roshan🇰🇷

    We propose a novel framework where baryon asymmetry can arise due to forbidden decay of dark matter (DM) enabled by finite temperature effects in the early universe. In order to implement it in a realistic setup, we consider the DM to be a singlet Dirac fermion which acquires a dark asymmetry from a scalar field $\Phi$ via Affleck-Dine mechanism. Due to finite-temperature effects, DM can decay in the early universe into leptons and a second Higgs doublet thereby transferring a part of the dark asymmetry into lepton asymmetry with the latter getting converted into baryon asymmetry subsequently via electroweak sphalerons. DM becomes stable below a critical temperature leading to a stable relic. While the scalar field $\Phi$ can play the role of inflaton with specific predictions for inflationary parameters, the setup also remains verifiable via astrophysical as well as laboratory based observations.

    hep-phastro-ph.COPRD(2023)·10 citations
31. 31*

    Limits on light primordial black holes from high-scale leptogenesis

    Roberta Calabrese🇮🇹 · Marco Chianese🇮🇹 · Jacob Gunn🇮🇹 · Gennaro Miele🇮🇹 · Stefano Morisi🇮🇹 · Ninetta Saviano🇮🇹

    We investigate the role that the evaporation of light primordial black holes may have played in the production of the baryon asymmetry of the Universe through the high-scale leptogenesis. In particular, for mass of primordial black hole in the range [$10^6$-$10^9$] g, we find a dilution of thermally generated lepton asymmetry via entropy injection in the primordial plasma after the sphaleron freeze-out. As a consequence, we can put strong constraints on the primordial black hole parameters, showing the mutual exclusion limits between primordial black holes and high-scale leptogenesis. Remarkably, we point out an interplay between the upper bound on the initial abundance of primordial black holes and the active neutrino mass scale.

    hep-phPRD(2023)·42 citations
32. 32*

    How Macroscopic Limits on Neutron Star Baryon Loss Yield Microscopic Limits on Non-Standard-Model Baryon Decay

    Jeffrey M. Berryman🇺🇸 · Susan Gardner🇺🇸 · Mohammadreza Zakeri🇺🇸

    We investigate how our baryon-loss limits from anomalous binary-pulsar period lengthening can be interpreted microscopically to yield specific constraints on the particle physics of baryon number violation within a neutron star. We focus on the possibility of anomalous baryon disappearance via dark baryon processes and on scenarios in which the produced dark-sector particles do not survive to influence the response of the star to baryon-number-violating effects. We flesh out the conditions for which this may occur, as well as other key assumptions. We then turn to the analysis of particle processes in the dense nuclear medium found at the core of a neutron star, employing the techniques of relativistic mean-field theory. Using our study of in-medium effects and limits on macroscopic baryon number violation we extract limits on in-vacuum baryon-number-violating processes, and we determine them for various equations of state. We conclude by noting the implications of our results for models of dark-sector-enabled baryogenesis.

    hep-phastro-ph.COastro-ph.HEgr-qc+1PRD(2024)·15 citations
33. 33*

    Local clustering of relic neutrinos with kinetic field theory

    Emil Brinch Holm🇩🇰 · Isabel M. Oldengott🇧🇪 · Stefan Zentarra🇨🇭

    The density of relic neutrinos is expected to be enhanced due to clustering in our local neighbourhood at Earth. We introduce a novel analytical technique to calculate the neutrino overdensity, based on kinetic field theory. Kinetic field theory is a particle-based theory for cosmic structure formation and in this work we apply it for the first time to massive neutrinos. The gravitational interaction is expanded in a perturbation series and we take into account the first-order contribution to the local density of relic neutrinos. For neutrino masses that are consistent with cosmological neutrino mass bounds, our results are in excellent agreement with state-of-the-art calculations.

    hep-phastro-ph.COPLB(2023)·14 citations
34. 34*

    Sensitivities to feebly interacting particles: public and unified calculations

    Maksym Ovchynnikov🇩🇪 · Jean-Loup Tastet🇪🇸 · Oleksii Mikulenko🇳🇱 · Kyrylo Bondarenko🇮🇹

    The idea that new physics could take the form of feebly interacting particles (FIPs) - particles with a mass below the electroweak scale, but which may have evaded detection due to their tiny couplings or very long lifetime - has gained a lot of traction in the last decade, and numerous experiments have been proposed to search for such particles. It is important, and now very timely, to consistently compare the potential of these experiments for exploring the parameter space of various well-motivated FIPs. The present paper addresses this pressing issue by presenting an open-source tool to estimate the sensitivity of many experiments - located at Fermilab or the CERN's SPS, LHC, and FCC-hh - to various models of FIPs in a unified way: the Mathematica-based code SensCalc.

    hep-phhep-exPRD(2023)·52 citations
35. 35*

    Growth of curvature perturbations for PBH formation \& detectable GWs in non-minimal curvaton scenario revisited

    Chao Chen🇨🇳 · Anish Ghoshal🇵🇱 · Zygmunt Lalak🇵🇱 · Yudong Luo🇨🇳 · Abhishek Naskar🇮🇳

    We revisit the growth of curvature perturbations in non-minimal curvaton scenario with a non-trivial field metric $\lambda (\varphi )$ where $\varphi$ is an inflaton field, and incorporate the effect from the non-uniform onset of curvaton's oscillation in terms of an axion-like potential. The field metric $\lambda (\varphi )$ plays a central role in the enhancement of curvaton field perturbation $\delta \chi$, serving as an effective friction term which can be either positive or negative, depending on the first derivative ${\lambda }_{,\varphi }$.Our analysis reveals that $\delta \chi$ undergoes the superhorizon growth when the condition ${\eta }_{\text{eff}}\equiv -2\sqrt{2ϵ}{M}_{\text{Pl}}\frac{{\lambda }_{,\varphi }}{\lambda }<-3$ is satisfied. This is analogous to the mechanism responsible for the amplification of curvature perturbations in the context of ultra-slow-roll inflation, namely the growing modes dominate curvature perturbations. As a case study, we examine the impact of a Gaussian dip in $\lambda (\varphi )$ and conduct a thorough investigation of both the analytical and numerical aspects of the inflationary dynamics.Our findings indicate that the enhancement of curvaton perturbations during inflation is not solely determined by the depth of the dip in $\lambda (\varphi )$. Rather, the first derivative ${\lambda }_{,\varphi }$ also plays a significant role, a feature that has not been previously highlighted in the literature. Utilizing the $\delta \mathcal{N}$ formalism, we derive analytical expressions for both the final curvature power spectrum and the non-linear parameter $f_{\text{NL}}$ in terms of an axion-like curvaton's potential leading to the non-uniform curvaton's oscillation. Additionally, the resulting primordial black hole abundance and scalar-induced gravitational waves are calculated, which provide observational windows for PBHs.

    ↳ astro-ph.COgr-qchep-phJCAP(2023)·40 citations
36. 36*

    Studying highly relativistic vortex-electron beams by atomic scattering

    V. K. Ivanov🇷🇺 · A. D. Chaikovskaia🇷🇺 · D. V. Karlovets🇷🇺

    We explore the opportunities of using electron scattering by screened Coulomb potential as a tool to retrieve properties of the relativistic vortex beams of electrons, such as their transverse momentum and orbital angular momentum (OAM). We focus on relativistic and ultra-relativistic regimes of the electron energies of at least several MeV and higher, in which the transverse beam momentum is typically much smaller than its longitudinal momentum. Different scattering scenarios for the incident electron beam are considered. In particular, the scattering by a very wide target can be used to probe the electron transverse momentum when its values are larger than 10 keV. The scattering by a target of a width comparable to that of the incident beam allows one to obtain information about the electron OAM. Varying target sizes in the range from couple to hundreds of nanometers, one can in principle distinguish OAM values from several units of $\hslash$ up to thousands and more.

    ↳ physics.atom-phhep-phPRA(2023)·11 citations
37. 37*

    Scale anomaly in a Lorentz and CPT-violating Quantum Electrodynamics

    J. S. Porto🇧🇷 · A. R. Vieira🇧🇷

    We compute the classical and the quantum breaking of the dilatation current in the minimal Lorentz and CPT-violating quantum electrodynamics. At the classical level, scale symmetry is broken by the general mass term \bar{\psi}M\psi and the Chern-Simons-like term. At the quantum level, it is broken by all expected observable fermion operators in the massless limit.

    ↳ hep-thhep-phEPL(2023)·5 citations
38. 38*

    Theoretical and Experimental Challenges in the Measurement of Neutrino Mass

    Jyotsna Singh🇮🇳 · M. Ibrahim Mirza🇺🇸

    Neutrino masses are yet unknown. We discuss the present state of effective electron anti-neutrino mass from $\beta$ decay experiments; effective Majorana neutrino mass from neutrinoless double-beta decay experiments; neutrino mass squared differences from neutrino oscillation: solar, atmospheric, reactor and accelerator based experiments; sum of neutrino masses from cosmological observations. Current experimental challenges in the determination of neutrino masses are briefly discussed. The main focus is devoted to contemporary experiments.

    ↳ hep-exhep-phAdv.High Energy Phys.(2023)·6 citations
39. 39*

    Revisiting coupled CDM-massive neutrino perturbations in diverse cosmological backgrounds

    Sourav Pal🇮🇳 · Rickmoy Samanta🇮🇳 · Supratik Pal🇮🇳

    Massive neutrinos are well-known to cause a characteristic suppression in the growth of structures at scales below the neutrino free-streaming length. A detailed understanding of this suppression is essential in the era of precision cosmology we are entering into, enabling us to better constrain the total neutrino mass and possibly probe (beyond)-$\Lambda$CDM cosmological model(s). Instead of the usual N-body simulation or Boltzmann solver, in this article we consider a two-fluid framework at the linear scales, where the neutrino fluid perturbations are coupled to the CDM (+ baryon) fluid via gravity at redshifts of interest. Treating the neutrino mass fraction $f_{\nu }$ as a perturbative parameter, we find solutions to the system with redshift-dependent neutrino free-streaming length in $\Lambda$CDM background via two separate approaches. The perturbative scale-dependent solution is shown to be in excellent agreement with numerical solution of the two-fluid equations valid to all orders in $f_{\nu }$, and also agrees with results from {\texttt{CLASS}} to a good accuracy. We further generalize the framework to incorporate different evolving dark energy backgrounds and found sub-percent level differences in the suppression, all of which lie within the observational uncertainty of BOSS-like surveys. We also present a brief discussion on the prospects of the current analysis in the context of upcoming missions.

    ↳ astro-ph.COgr-qchep-phJCAP(2023)·6 citations
40. 40*

    Relation between the escort average in microcanonical ensemble and the escort average in canonical ensemble in the Tsallis statistics

    Masamichi Ishihara

    We studied the escort averages in microcanonical and canonical ensembles in the Tsallis statistics of entropic parameter $q>1$. The quantity $(q-1)$ is the measure of the deviation from the Boltzmann-Gibbs statistics. We derived the relation between the escort average in the microcanonical ensemble and the escort average in the canonical ensemble. Conditions arise by requiring that the integrals appeared in the canonical ensemble do not diverge. A condition is the relation between the heat capacity $C_V^{\mathrm{CE}}$ at constant volume in the canonical ensemble and the entropic parameter $q$: $0<(q-1)C_V^{\mathrm{CE}}<1$. This condition gives the known condition when $C_V^{\mathrm{CE}}$ equals the number of ingredients $N$. With the derived relation, we calculated the energy, the energy fluctuation, and the difference between the canonical ensemble and the microcanonical ensemble in the expectation value of the square of Hamiltonian. The difference between the microcanonical ensemble and the canonical ensemble in energy is small because of the condition. The heat capacity $C_V^{\mathrm{CE}}$ and the quantity $(q-1)$ are related to the energy fluctuation and the difference. It was shown that the magnitude of the relative difference $|(S_{\mathrm{R}q}^{\mathrm{CE}}-S_{\mathrm{R}q}^{\mathrm{ME}})/S_{\mathrm{R}q}^{\mathrm{ME}}|$ is small when the number of free particles is large, where $S_{\mathrm{R}q}^{\mathrm{ME}}$ is the Rényi entropy in the microcanonical ensemble and $S_{\mathrm{R}q}^{\mathrm{CE}}$ is the Rényi entropy in the canonical ensemble. The similar result was also obtained for the Tsallis entropy.

    ↳ cond-mat.stat-mechhep-phhep-thEur.Phys.J.Plus(2023)·3 citations
41. 41*

    Halo formation and evolution in scalar field dark matter and cold dark matter: New insights from the fluid approach

    Horst Foidl🇦🇹 · Tanja Rindler-Daller🇦🇹 · Werner Zeilinger

    (abridged) We present simulations of halo formation and evolution in scalar field dark matter (SFDM) cosmologies in the Thomas-Fermi regime, aka ``SFDM-TF", where a strong repulsive 2-particle self-interaction (SI) is included, being a valuable alternative to CDM, with the potential to resolve its ``cusp-core" problem. In general, SFDM behaves like a quantum fluid. Previous literature has presented two fluid approximations for SFDM-TF, as well as simulations of halo formation. These results confirmed earlier expectations and are generally in mutual agreement, but discrepancies were also reported. Therefore, we perform dedicated 3D cosmological simulations for the SFDM-TF model, applying both fluid approximations, as well as for CDM. Our results are very well in accordance with previous works and extend upon them, in that we can explain the reported discrepancies as a result of different simulation setups. We find some interesting details: The evolution of both SFDM-TF and CDM halos follows a 2-stage process. In the early stage, the density profile in the center becomes close to a $(n=1.5)$-polytropic core, dominated by an "effective" velocity-dispersion pressure $P_{\sigma }$ which is common to both dark matter models. Consecutively, for CDM halos, the core transitions into a central cusp. In SFDM-TF halos, the additional pressure $P_{\text{SI}}$ due to SI determines the second stage of the evolution, where the central region follows closely a $(n=1)$-polytropic core, embedded in a nearly isothermal envelope, i.e. the outskirts are similar to CDM. We also encounter a new effect, namely a late-time expansion of both polytropic core plus envelope, because the size of the almost isothermal halo envelope is affected by the expansion of the background universe. So, an initial primordial core of $\sim 100$ pc can evolve into a larger core of $\gtrsim 1$ kpc, even without feedback from baryons.

    ↳ astro-ph.GAastro-ph.COhep-phphysics.flu-dynPRD(2023)·12 citations
42. 42*

    Impact of the damping tail on neutrino mass constraints

    Eleonora Di Valentino🇬🇧 · Stefano Gariazzo🇮🇹 · William Giarè🇬🇧 · Olga Mena🇪🇸

    Model-independent mass limits assess the robustness of current cosmological measurements of the neutrino mass scale. Consistency between high-multipole and low-multiple Cosmic Microwave Background observations measuring such scale further valuate the constraining power of present data. We derive here up-to-date limits on neutrino masses and abundances exploiting either the Data Release 4 of the Atacama Cosmology Telescope (ACT) or the South Pole Telescope polarization measurements from SPT-3G, envisaging different non-minimal background cosmologies and marginalizing over them. By combining these high-$\ell$ observations with Supernova Ia, Baryon Acoustic Oscillations (BAO), Redshift Space Distortions (RSD) and a prior on the reionization optical depth from WMAP data, we find that the marginalized bounds are competitive with those from Planck analyses. We obtain $\sum m_{\nu }<0.139$ eV and $N_{\text{eff}}=2.82\pm 0.25$ in a dark energy quintessence scenario, both at $95\%$ CL. These limits translate into $\sum m_{\nu }<0.20$ eV and $N_{\text{eff}}=2.79_{-0.28}^{+0.30}$ after marginalizing over a plethora of well-motivated fiducial models. Our findings reassess both the strength and the reliability of cosmological neutrino mass constraints.

    ↳ astro-ph.COhep-phPRD(2023)·20 citations
43. 43*

    Clustering of Primordial Black Holes from QCD Axion Bubbles

    Kentaro Kasai🇯🇵 · Masahiro Kawasaki🇯🇵 · Naoya Kitajima🇯🇵 · Kai Murai🇯🇵 · Shunsuke Neda🇯🇵 · Fuminobu Takahashi🇯🇵

    We study the clustering of primordial black holes (PBHs) and axion miniclusters produced in the model proposed to explain the LIGO/Virgo events or the seeds of the supermassive black holes (SMBHs) in arXiv:2006.13137. It is found that this model predicts large isocurvature perturbations due to the clustering of PBHs and axion miniclusters, from which we obtain stringent constraints on the model parameters. Specifically, for the axion decay constant $f_a=10^{16}\mathrm{GeV}$, which potentially accounts for the seeds of the SMBHs, the PBH fraction in dark matter should be $f_{\mathrm{PBH}}\lesssim 7\times 10^{-10}$. Assuming that the mass of PBHs increases by more than a factor of $\mathcal{O}(10)$ due to accretion, this is consistent with the observed abundance of SMBHs. On the other hand, for $f_a=10^{17}\mathrm{GeV}$ required to produce PBHs of masses detected in the LIGO/Virgo, the PBH fraction should be $f_{\mathrm{PBH}}\lesssim 6\times 10^{-8}$, which may be too small to explain the LIGO/Virgo events, although there is a significant uncertainty in calculating the merger rate in the presence of clustering.

    ↳ astro-ph.COhep-phJCAP(2023)·13 citations
44. 44*

    Vacuum-defect wormholes and a mirror world

    F. R. Klinkhamer

    We have recently discovered a smooth vacuum-wormhole solution of the first-order equations of general relativity. Here, we obtain the corresponding multiple-vacuum-wormhole solution. Assuming that our world is essentially Minkowski spacetime with a large number of these vacuum-defect wormholes inserted, there is then another flat spacetime with opposite spatial orientation, which may be called a "mirror" world. We briefly discuss some phenomenological aspects and point out that there will be no significant vacuum-Cherenkov radiation in our world, so that ultrahigh-energy cosmic rays do not constrain the typical size and separation of the wormhole mouths (different from the constraints obtained for a single Minkowski spacetime with similar defects). Other signatures from a "gas" of vacuum-defect wormholes are mentioned, including a possible time machine.

    ↳ gr-qchep-phhep-thActa Phys.Polon.B(2023)·16 citations
45. 45*

    Mapping Dark Matter in the Milky Way using Normalizing Flows and Gaia DR3

    Sung Hak Lim🇺🇸 · Eric Putney🇺🇸 · Matthew R. Buckley🇺🇸 · David Shih🇺🇸

    We present a novel, data-driven analysis of Galactic dynamics, using unsupervised machine learning -- in the form of density estimation with normalizing flows -- to learn the underlying phase space distribution of 6 million nearby stars from the Gaia DR3 catalog. Solving the equilibrium collisionless Boltzmann equation, we calculate -- for the first time ever -- a model-free, unbinned estimate of the local acceleration and mass density fields within a 3 kpc sphere around the Sun. As our approach makes no assumptions about symmetries, we can test for signs of disequilibrium in our results. We find our results are consistent with equilibrium at the 10% level, limited by the current precision of the normalizing flows. After subtracting the known contribution of stars and gas from the calculated mass density, we find clear evidence for dark matter throughout the analyzed volume. Assuming spherical symmetry and averaging mass density measurements, we find a local dark matter density of $0.47\pm 0.05$ GeV/cm${}^3$. We compute the dark matter density at four radii in the stellar halo and fit to a generalized NFW profile. Although the uncertainties are large, we find a profile broadly consistent with recent analyses.

    ↳ astro-ph.GAhep-phJCAP(2025)·34 citations
46. 46*

    Spin-2 dark matter from inflation

    Mohammad Ali Gorji🇪🇸

    The seed of dark matter can be generated from light spectator fields during inflation through a similar mechanism that the seed of observed large scale structures are produced from the inflaton field. The accumulated energy density of the corresponding excited modes, which is subdominant during inflation, dominates energy density of the universe later around the time of matter and radiation equality and plays the role of dark matter. For spin-2 spectator fields, Higuchi bound may seem to prevent excitation of such light modes since deviation of the inflationary background from the exact de Sitter spacetime is very small. However, sizable interactions with the inflaton field breaks (part of) isometries of the de Sitter space in the inflationary background and relaxes the Higuchi bound. Looking for this possibility in the context of effective field theory of inflation, we suggest a dark matter model consisting of spin-2 particles that produce during inflation.

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2023)·12 citations
47. 47*

    Primordial black holes in the curvaton model: possible connections to pulsar timing arrays and dark matter

    Giacomo Ferrante🇫🇷 · Gabriele Franciolini🇮🇹 · Antonio Junior Iovino🇮🇹 · Alfredo Urbano🇮🇹

    We revise primordial black holes (PBHs) production in the axion-curvaton model, in light of recent developments in the computation of their abundance accounting for non-gaussianities (NGs) in the curvature perturbation up to all orders. We find that NGs intrinsically generated in such scenarios have a relevant impact on the phenomenology associated to PBHs and, in particular, on the relation between the abundance and the signal of second-order gravitational waves. We show that this model could explain both the totality of dark matter in the asteroid mass range and the tentative signal reported by the NANOGrav and IPTA collaborations in the nano-Hz frequency range. En route, we provide a new, explicit computation of the power spectrum of curvature perturbations going beyond the sudden-decay approximation.

    ↳ astro-ph.COgr-qchep-phJCAP(2023)·63 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.