Thu·Nov 2, 2023Thursday·November 2, 2023

1. 01*

   Anatomy of astrophysical echoes from axion dark matter

   Elisa Todarello🇮🇹 · Francesca Calore🇫🇷 · Marco Regis🇮🇹

   If the dark matter in the Universe is made of $\mu$eV axion-like particles (ALPs), then a rich phenomenology can emerge in connection to their stimulated decay into two photons. We discuss the ALP stimulated decay induced by electromagnetic radiation from Galactic radio sources. Three signatures, made by two echoes and one collinear emission, are associated with the decay, and can be simultaneously detected, offering a unique opportunity for a clear ALP identification. We derive the formalism associated with such signatures starting from first principles, and providing the relevant equations to be applied to study the ALP phenomenology. We then focus on the case of Galactic pulsars as stimulating sources and derive forecasts for future observations, which will be complementary to helioscopes and haloscopes results

   hep-phastro-ph.COJCAP(2024)·10 citations
2. 02*

   Seeking Truth and Beauty in Flavor Physics with Machine Learning

   Konstantin T. Matchev🇺🇸 · Katia Matcheva🇺🇸 · Pierre Ramond🇺🇸 · Sarunas Verner🇺🇸

   The discovery process of building new theoretical physics models involves the dual aspect of both fitting to the existing experimental data and satisfying abstract theorists' criteria like beauty, naturalness, etc. We design loss functions for performing both of those tasks with machine learning techniques. We use the Yukawa quark sector as a toy example to demonstrate that the optimization of these loss functions results in true and beautiful models.

   hep-phcs.LGmath-phmath.MP3 citations
3. 03*

   New Physics in Single Resonant Top Quarks

   Shelley Tong🇺🇸 · James Corcoran🇺🇸 · Max Fieg🇺🇸 · Michael Fenton🇺🇸 · Daniel Whiteson🇺🇸

   Searches for new physics in the top quark sector are of great theoretical interest, yet some powerful avenues for discovery remain unexplored. We characterize the expected statistical power of the LHC dataset to constrain the single production of heavy top partners $T$ decaying to a top quark and a photon or a top quark and a gluon. We describe an effective interaction which could generate such production, though the limits apply to a range of theoretical models. We find sensitivity to cross sections in the $10^2-10^5$ fb range, for $T$ masses between 300 and 1000 GeV, depending on decay mode.

   hep-phJHEP(2024)·3 citations
4. 04*

   Correlation between the symmetry energy slope and the deconfinement phase transition

   Luiz L. Lopes🇧🇷 · Debora P. Menezes🇧🇷 · Mateus R. Pelicer🇺🇸

   We study how the nuclear symmetry energy slope ($L$) can affect the hadron-quark phase transition and neutron star properties. We show that the main physical quantities as the critical chemical potential and pressure are strongly influenced by the symmetry energy slope. In extreme cases, the total amount of deconfined quarks can reach up to 99$\%$ of the hybrid star mass.

   hep-phastro-ph.HEnucl-thPRC(2024)·8 citations
5. 05*

   QCD Factorization from Light-ray OPE

   Hao Chen🇨🇳

   The energy-energy correlator (EEC) in Quantum Chromodynamics (QCD) serves as an important event shape for probing the substructure of jets in high-energy collisions. A significant progress has been make in understanding the collinear limit, where the angle between two detectors approaches zero, from the factorization formula in QCD and the light-ray Operator Product Expansion (OPE) in Conformal Field Theory. Building upon prior research on the renormalization of light-ray operators, we take an innovative step to extend the light-ray OPE into non-conformal contexts, with a specific emphasis on perturbative QCD. Our proposed form of the light-ray OPE is constrained by three fundamental properties: Lorentz symmetry, renormalization group invariance, and constraints from physical observables. This extension allows us to derive a factorization formula for the collinear limit of EEC, facilitating the future exploration and understanding on subleading power corrections in collinear limit.

   hep-phhep-thJHEP(2024)·42 citations
6. 06*

   Constraining the General Oscillatory Inflaton Potential with Freeze-in Dark Matter and Gravitational Waves

   Jose A. R. Cembranos🇪🇸 · Mindaugas Karčiauskas🇪🇸

   The reheating phase after inflation is one of the least observationally constrained epochs in the evolution of the Universe. The forthcoming gravitational wave observatories will enable us to constrain at least some of the non-standard scenarios. For example, models where the radiation bath is produced by the perturbative inflaton decay that oscillates around the minimum of the potential of the form $V\propto {\varphi }^{2n}$, with $n>2$. In such scenarios a part of the inflationary gravitational wave spectrum becomes blue tilted, making it observable, depending on the inflation energy scale and the reheating temperature. The degeneracy between the latter two parameters can be broken if dark matter in the Universe is produced via the freeze-in mechanism. The combination of the independent measurement of dark matter mass with gravitational wave observations makes it possible to constrain the reheating temperature and the energy scale at the end of inflation, at least within some parameter ranges.

   hep-phastro-ph.COgr-qcJCAP(2024)·0 citations
7. 07*

   Diffractive single and di-hadron production at the NLO in a saturation framework

   Michael Fucilla🇫🇷 · Andrey Grabovsky🇷🇺 · Emilie Li🇫🇷 · Lech Szymanowski🇵🇱 · Samuel Wallon🇫🇷

   Motivated by the need to increase the precision of theoretical predictions to test saturation physics at both the LHC and the EIC, we compute the cross-sections for the diffractive single and di-hadron production at the NLO in the shockwave formalism.

   hep-phPoS(2024)·1 citation
8. 08*

   The $\rho (770,1450)\to \omega \pi$ contributions for three-body decays $B\to {\bar{D}}^{(\ast )}\omega \pi$

   Yu-Shan Ren🇨🇳 · Ai-Jun Ma🇨🇳 · Wen-Fei Wang🇨🇳

   The decays $B\to {\bar{D}}^{(\ast )}\omega \pi$ are very important for the investigation of $\rho$ excitations and the test of factorization hypothesis for $B$ meson decays. The $B^{+}\to {\bar{D}}^{(\ast )0}\omega {\pi }^{+}$ and $B^0\to D^{(\ast )-}\omega {\pi }^{+}$ have been measured by different collaborations but without any predictions for their observables on theoretical side. In this work, we study the contributions of $\rho (770,1450)\to \omega \pi$ for the cascade decays $B^{+}\to {\bar{D}}^{(\ast )0}{\rho }^{+}\to {\bar{D}}^{(\ast )0}\omega {\pi }^{+}$, $B^0\to D^{(\ast )-}{\rho }^{+}\to D^{(\ast )-}\omega {\pi }^{+}$ and $B_s^0\to D_s^{(\ast )-}{\rho }^{+}\to D^{(\ast )-}\omega {\pi }^{+}$. We introduce $\rho (770,1450)\to \omega \pi$ subprocesses into the distribution amplitudes for $\omega \pi$ system via the vector form factor $F_{\omega \pi }(s)$ and then predict the branching fractions for the first time for concerned quasi-two-body decays with $\rho (770,1450)\to \omega \pi$, as well as the corresponding longitudinal polarization fractions ${\Gamma }_L/\Gamma$ for the cases with the vector ${\bar{D}}^{\ast 0}$ or $D_{(s)}^{\ast -}$ in their final states. The branching fractions of these quasi-two-body decays are predicted at the order of $10^{-3}$, which can be detected at the LHCb and Belle-II experiments. The predictions for the decays $B^0\to D^{\ast -}\rho (770{)}^{+}\to D^{\ast -}\omega {\pi }^{+}$ and $B^0\to D^{\ast -}\rho (1450{)}^{+}\to D^{\ast -}\omega {\pi }^{+}$ agree well with the measurements from Belle Collaboration. In order to avoid the pollution from annihilation Feynman diagrams, we recommend to take the $B_s^0\to D_s^{\ast -}\rho (770,1450{)}^{+}$ decays, which have only emission diagrams at quark level, to test the factorization hypothesis for $B$ decays.

   hep-phhep-exJHEP(2024)·6 citations
9. 09*

   Nuclear PDFs After the First Decade of LHC Data

   M. Klasen🇩🇪 · H. Paukkunen🇫🇮

   We present a review of the conceptual basis, present knowledge and recent progress in the field of global analysis of nuclear parton distribution functions (PDFs). After introducing the theoretical foundations and methodological approaches for the extraction of nuclear PDFs from experimental data, we discuss how different measurements in fixed-target and collider experiments provide increasingly precise constraints on various aspects of nuclear PDFs, including shadowing, antishadowing, the EMC effect, Fermi motion, flavor separation, deuteron binding, target-mass and other higher-twist effects. Particular emphasis is given to measurements carried out in proton-lead collisions at the Large Hadron Collider, which have revolutionized the global analysis during the past decade. These measurements include electroweak-boson, jet, light-hadron, and heavy-flavor observables. Finally, we outline the expected impact of the future Electron Ion Collider and discuss the role and interplay of nuclear PDFs with other branches of nuclear, particle and astroparticle physics.

   hep-phhep-exnucl-exnucl-thAnn.Rev.Nucl.Part.Sci.(2024)·86 citations
10. 10*

    Coherent electroproduction of vector mesons on spinless targets

    S.I. Manaenkov🇷🇺

    The amplitude ratios of vector-meson production by heavy photons on spinless targets are shown to can be explicitly expressed in terms of the spin-density-matrix elements (SDMEs) only if the lepton beam is longitudinally polarized. Making use of the amplitude ratios as free fit parameters instead of the SDMEs reduces the number of the real parameters in data description from 23 to 8. The exact formula for $R=\frac{d{\sigma }_L}{dt}/\frac{d{\sigma }_T}{dt}$ in terms of the SDMEs is obtained for spinless targets and the new approximate formula for $R$ is proposed for nucleon targets.

    hep-phPhys.Part.Nucl.Lett.(2024)·2 citations
11. 11*

    Evaluating scattering amplitudes with pySecDec 1.6

    Vitaly Magerya🇩🇪

    pSecDec is a computer tool to evaluate Feynman integrals and their weighted sums (amplitudes) using the method of sector decomposition and numerical integration. The new release of pySecDec version 1.6 comes with a significant performance boost (3x-9x in common scenarios), and new features to make the evaluation and asymptotic expansion of amplitudes and integrals easier and faster. In this article we briefly review these features.

    hep-phPoS(2024)·0 citations
12. 12*

    Studying the production mechanisms of light meson resonances in two-pion photoproduction

    Łukasz Bibrzycki🇵🇱 · Nadine Hammoud🇵🇱 · Vincent Mathieu🇪🇸 · Robert J. Perry🇪🇸 · Adam P. Szczepaniak🇺🇸

    A theoretical model of two-pion photoproduction is presented. The model encodes the prominent $\rho (770)$ resonance and the expected leading background contribution coming from the Deck mechanism. To validate the model, angular moments are computed and compared with the CLAS dataset. After fitting a number of free parameters, the model provides a good description of the data.

    hep-phnucl-thEPJ Web Conf.(2024)·0 citations
13. 13*

    Sensitivities to feebly interacting particles: public and unified calculations

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

    The increasing interest in Long-Lived Particles (LLPs) has led to numerous proposed experiments in order to search for them. However, the sensitivity estimates published by these experiments tend to rely on disparate assumptions. To ensure an accurate comparison of their potential to find LLPs, a unified estimation of their sensitivity is therefore required. In this contribution, we introduce \texttt{SensCalc}, a \texttt{Mathematica}-based code that uses a semi-analytic approach to calculate the event rate of GeV-scale LLPs, and we present several case studies.

    hep-phhep-exPoS(2024)·0 citations
14. 14*

    Search for new particles at the ILC

    María Teresa Núñez Pardo de Vera🇩🇪

    Although the LHC experiments have searched for and excluded many proposed new particles up to masses close to 1 TeV, there are many scenarios that are difficult to address at a hadron collider. This talk will review a number of these scenarios and present the expectations for searches at an electron-positron collider such as the International Linear Collider. The cases discussed include SUSY in strongly or moderately compressed models, heavy neutrinos, heavy vector bosons coupling to the s-channel in $e^{+}{e}^{-}$ annihilation, and new scalars.

    hep-phPoS(2024)·0 citations
15. 15*

    The first-order factorizable contributions to the three-loop massive operator matrix elements $A_{Qg}^{(3)}$ and $\Delta A_{Qg}^{(3)}$

    J. Ablinger🇦🇹 · A. Behring🇨🇭 · J. Blümlein🇩🇪 · A. De Freitas🇦🇹 · A. von Manteuffel🇩🇪 · C. Schneider🇦🇹 · K. Schönwald🇨🇭

    The unpolarized and polarized massive operator matrix elements $A_{Qg}^{(3)}$ and $\Delta A_{Qg}^{(3)}$ contain first-order factorizable and non-first-order factorizable contributions in the determining difference or differential equations of their master integrals. We compute their first-order factorizable contributions in the single heavy mass case for all contributing Feynman diagrams. Moreover, we present the complete color-$\zeta$ factors for the cases in which also non-first-order factorizable contributions emerge in the master integrals, but cancel in the final result as found by using the method of arbitrary high Mellin moments. Individual contributions depend also on generalized harmonic sums and on nested finite binomial and inverse binomial sums in Mellin $N$-space, and correspondingly, on Kummer-Poincaré and square-root valued alphabets in Bjorken-$x$ space. We present a complete discussion of the possibilities of solving the present problem in $N$-space analytically and we also discuss the limitations in the present case to analytically continue the given $N$-space expressions to $N\in \mathbb{C}$ by strict methods. The representation through generating functions allows a well synchronized representation of the first-order factorizable results over a 17-letter alphabet. We finally obtain representations in terms of iterated integrals over the corresponding alphabet in $x$-space, also containing up to weight {\sf w = 5} special constants, which can be rationalized to Kummer-Poincaré iterated integrals at special arguments. The analytic $x$-space representation requires separate analyses for the intervals $x\in [0,1/4],[1/4,1/2],[1/2,1]$ and $x>1$. We also derive the small and large $x$ limits of the first-order factorizable contributions.

    hep-phhep-thNPB(2024)·41 citations
16. 16*

    Polarized fragmenting jet functions in Inclusive and Exclusive Jet Production

    Zhong-Bo Kang🇺🇸 · Hongxi Xing🇨🇳 · Fanyi Zhao🇺🇸 · Yiyu Zhou🇺🇸

    In this work, we present a complete theoretical framework for analyzing the distribution of polarized hadrons within jets, with and without measuring the transverse momentum relative to the standard jet axis. Using soft-collinear effective theory (SCET), we derive the factorization and provide the theoretical calculation of both semi-inclusive and exclusive fragmenting jet functions (FJFs) under longitudinal and transverse polarization. With the polarized FJFs, one gains access to a variety of new observables that can be used for extracting both collinear and transverse momentum dependent parton distribution functions (PDFs) and fragmentation functions (FFs). As examples, we provide numerical results for the spin asymmetry $A_{TU,T}^{\cos ({\varphi }_S-{\hat{\varphi }}_{S_h})}$ from polarized semi-inclusive hadron-in-jet production in polarized $pp$ collisions at RHIC kinematics, where a transversely polarized quark would lead to the transverse spin of the final-state hadron inside the jet and is thus sensitive to the transversity fragmentation functions. Similarly, another spin asymmetry, $A_{TU,L}^{\cos ({\varphi }_q-{\varphi }_S)}$ from polarized exclusive hadron-in-jet production in polarized $ep$ collisions at EIC kinematics would allow us to access the helicity fragmentation functions. These observables demonstrate promising potential in investigating transverse momentum dependent PDFs and FFs and are worthwhile for further measurements.

    hep-phhep-exnucl-exnucl-thJHEP(2024)·10 citations
17. 17*

    Dark Matter in A Mirror Solution to the Strong CP Problem

    Quentin Bonnefoy🇺🇸 · Lawrence Hall🇺🇸 · Claudio Andrea Manzari🇺🇸 · Amara McCune🇺🇸 · Christiane Scherb🇺🇸

    We study thermal production of dark matter (DM) in a realization of the minimal models of Ref.~\cite{Bonnefoy:2023afx}, where parity is used to solve the strong CP problem by transforming the entire Standard Model (SM) into a mirror copy. Although the mirror electron $e^{\prime }$ is a good DM candidate, its viability is mired by the presence of the mirror up-quark $u^{\prime }$, whose abundance is intimately related to the $e^{\prime }$ abundance and must be suppressed. This can be achieved through a sequential freeze-in mechanism, where mirror photons are first produced from SM gluons, and then the mirror photons produce $e^{\prime }$. After computing the details of this double freeze-in, we discuss the allowed parameter space of the model, which lies at the threshold of experimental observations. We find that this origin of $e^{\prime }$ DM requires a low reheating temperature after inflation and is consistent with the baryon asymmetry arising from leptogenesis, providing mirror neutrinos have a significant degeneracy. Finally, we show that this $e^{\prime }$ DM is not compatible with Higgs Parity, the simplest scheme with exact parity, unless SM parameters deviate significantly from their central values or the minimal model is extended.

    hep-phhep-exhep-thPRD(2024)·5 citations
18. 18*

    Constraining Dark Matter-Proton Scattering from Molecular Cloud Ionization

    Carlos Blanco🇺🇸 · Ian Harris🇺🇸 · Yonatan Kahn🇺🇸 · Anirudh Prabhu🇺🇸

    Optically dense clouds in the interstellar medium composed predominantly of molecular hydrogen, known as molecular clouds, are sensitive to energy injection in the form of photon absorption, cosmic-ray scattering, and dark matter (DM) scattering. The ionization rates in dense molecular clouds are heavily constrained by observations of abundances of various molecular tracers. Recent studies have set constraints on the DM-electron scattering cross section using measurements of ionization rates in dense molecular clouds. Here we calculate the analogous bounds on the DM-proton cross section using the molecular Migdal effect, recently adapted from the neutron scattering literature to the DM context. These bounds may be the strongest limits on a strongly-coupled DM subfraction, and represent the first application of the Migdal effect to astrophysical systems.

    hep-phastro-ph.GAPRD(2024)·5 citations
19. 19*

    The intrinsic charm quark valence distribution of the proton

    Richard D. Ball🇬🇧 · Alessandro Candido🇮🇹 · Juan Cruz-Martinez🇨🇭 · Stefano Forte🇮🇹 · Tommaso Giani🇳🇱 · Felix Hekhorn🇮🇹 · Giacomo Magni🇳🇱 · Emanuele R. Nocera🇮🇹 · Juan Rojo🇳🇱 · Roy Stegeman🇬🇧

    We provide a first quantitative indication that the wave function of the proton contains unequal distributions of charm quarks and antiquarks, i.e. a nonvanishing intrinsic valence charm distribution. A significant nonvanishing valence component cannot be perturbatively generated, hence our results reinforce previous evidence that the proton contains an intrinsic (i.e., not radiatively generated) charm quark component. We establish our result through a determination of the parton distribution functions (PDFs) of charm quarks and antiquarks in the proton. We propose two novel experimental probes of this intrinsic charm valence component: D-meson asymmetries in Z+c-jet production at the LHCb experiment, and flavor-tagged structure functions at the Electron-Ion Collider.

    hep-phhep-exPRD(2024)·61 citations
20. 20*

    Anomaly Enforced Gaplessness for Background Flux Anomalies and Symmetry Fractionalization

    T. Daniel Brennan🇺🇸 · Aiden Sheckler🇺🇸

    Anomalous symmetries are known to strongly constrain the possible IR behavior along any renormalization group (RG) flow. Recently, the extension of the notion of symmetry in QFT has provided new types of anomalies with a corresponding new class of constraints on RG flows. In this paper, we derive the constraints imposed on RG flows from anomalies that can only be activated in the presence of specific background fluxes even though they do not necessarily correspond to a symmetry. We show that such anomalies can only be matched by gapped theories that exhibit either spontaneous symmetry breaking or symmetry fractionalization. In addition, we exhibit previously unstudied examples of these flux background anomalies that arise in $4d$ QCD and $4d$ SUSY QCD.

    ↳ hep-thcond-mat.str-elhep-phJHEP(2024)·12 citations
21. 21*

    Neutron star mass in dark matter clumps

    Maksym Deliyergiyev🇨🇭 · Antonino Del Popolo🇮🇹 · Morgan Le Delliou🇨🇳

    This paper investigates a hypothesis proposed in previous research relating neutron star (NS) mass and its dark matter (DM) accumulation. As DM accumulates, NS mass decreases, predicting lower NS masses toward the Galactic center. Due to limited NSs data near the galactic center, we examine NSs located within DM clumps. Using the CLUMPY code simulations, we determine the DM clumps distribution, with masses from 10 to $10^8$ $M_{\odot }$ and scales from $10^{-3}$ to 10 kpc. These clumps' DM exhibit a peak at the center, tapering toward the outskirts, resembling our Galaxy's DM distribution. We analyse these DM clumps' NS mass variations, considering diverse DM particle masses and galaxy types. We find relatively stable NS mass within 0.01 to 5 kpc from the clump center. This stability supports the initial hypothesis, particularly for NSs located beyond 0.01 kpc from the clump center, where NS mass reaches a plateau around 0.1 kpc. Nevertheless, NS mass near the clump's periphery reveals spatial dependence: NS position within DM clumps influences its mass in Milky Way-type galaxies. Moreover, this dependence varies with the DM model considered. In summary, our study investigates the proposed link between NS mass and DM accumulation by examining NSs within DM clumps. While NS mass remains stable at certain distances from the clump center, spatial dependencies arise near the clump's outer regions, contingent on the specific DM model.

    ↳ astro-ph.GAastro-ph.COastro-ph.HEhep-phMNRAS(2023)·14 citations
22. 22*

    Pulsar Timing Array Signature from Oscillating Metric Perturbations due to Ultra-light Axion

    Jai-chan Hwang🇰🇷 · Donghui Jeong🇺🇸 · Hyerim Noh🇰🇷 · Clemente Smarra🇮🇹

    A coherently oscillating ultra-light axion can behave as dark matter. In particular, its coherently oscillating pressure perturbations can source an oscillating scalar metric perturbation, with a characteristic oscillation frequency which is twice the axion Compton frequency. A candidate in the mass range $10^{(-24,-21)}\mathrm{eV}$ can provide a signal in the frequency range tested by current and future Pulsar Timing Array (PTA) programs. Involving the pressure perturbations in a highly nonlinear environment, such an analysis demands a relativistic and nonlinear treatment. Here, we provide a rigorous derivation of the effect assuming weak gravity and slow-motion limit of Einstein's gravity in zero-shear gauge and show that dark matter's velocity potential determines the oscillation phase and frequency change. A monochromatic PTA signal correlated with the velocity field would confirm the prediction, for example, by cross-correlating the PTA results with the future local velocity flow measurements.

    ↳ astro-ph.COgr-qchep-phJCAP(2024)·8 citations
23. 23*

    Gravitational Waves from Preheating in Inflation with Weyl Symmetry

    Wei-Yu Hu🇨🇳 · Qing-Yang Wang🇨🇳 · Yan-Qing Ma🇨🇳 · Yong Tang🇨🇳

    Inflation with Weyl scaling symmetry provides a viable scenario that can generate both the nearly scaling invariant primordial density fluctuation and a dark matter candidate. Here we point out that, in additional to the primordial gravitational waves (GWs) from quantum fluctuations, the production of high-frequency GWs from preheating in such inflation models can provide an another probe of the inflationary dynamics. We conduct both linear analytical analysis and nonlinear numerical lattice simulation in a typical model. We find that significant stochastic GWs can be produced and the frequency band is located around $10^8$ Hz $\sim$ $10^9$ Hz, which might be probed by future resonance-cavity experiments.

    ↳ astro-ph.COgr-qchep-phPRD(2024)·9 citations
24. 24*

    Relativistic second-order dissipative and anisotropic fluid dynamics in the relaxation-time approximation for an ideal gas of massive particles

    Victor Ambrus🇷🇴 · Etele Molnár🇵🇱 · Dirk H. Rischke🇩🇪

    In this paper, we study all transport coefficients of second-order dissipative fluid dynamics derived by V. E. Ambrus et al. [Phys. Rev. D 106, 076005 (2022)] from the relativistic Boltzmann equation in the relaxation-time approximation for the collision integral. These transport coefficients are computed for a classical ideal gas of massive particles, with and without taking into account the conservation of intrinsic quantum numbers. Through rigorous comparison between kinetic theory, second-order dissipative fluid dynamics, and leading-order anisotropic fluid dynamics for a (0+1)--dimensional boost-invariant flow scenario, we show that both fluid-dynamical theories describe the early far-from-equilibrium stage of the expansion reasonably well.

    ↳ nucl-thhep-phphysics.flu-dynPRD(2024)·10 citations
25. 25*

    Discovery of four pulsars in a pilot survey at intermediate Galactic latitudes with FAST

    Q. J. Zhi · J. T. Bai🇨🇳 · S. Dai🇦🇺 · X. Xu🇨🇳 · S. J. Dang🇨🇳 · L. H. Shang · R. S. Zhao · D. Li🇨🇳 · W. W. Zhu🇨🇳 · N. Wang · J. P. Yuan🇨🇳 · P. Wang and 12 other authors

    We present the discovery and timing results of four pulsars discovered in a pilot survey at intermediate Galactic latitudes with the Five-hundred Aperture Spherical Telescope (FAST). Among these pulsars, two belong to the category of millisecond pulsars (MSPs) with spin periods of less than 20 ms. The other two fall under the classification of "mildly recycled" pulsars, with massive white dwarfs as companions. Remarkably, this small survey, covering an area of 4.7 $de{g}^2$ , led to the discovery of four recycled pulsars. Such success underscores the immense potential of future surveys at intermediate Galactic latitudes. In order to assess the potential yield of MSPs, we conducted population simulations and found that both FAST and Parkes new phased array feed surveys, focusing on intermediate Galactic latitudes, have the capacity to uncover several hundred new MSPs.

    ↳ astro-ph.HEastro-ph.GAhep-phApJ(2024)·6 citations
26. 26*

    Progress in the partial-wave analysis methods at COMPASS

    Julien Beckers🇩🇪 · Florian Kaspar🇩🇪 · Jakob Knollmüller🇩🇪

    We study the excitation spectrum of light and strange mesons in diffractive scattering. We identify different hadron resonances through partial wave analysis, which inherently relies on analysis models. Besides statistical uncertainties, the model dependence of the analysis introduces dominant systematic uncertainties. We discuss several of their sources for the ${\pi }^{-}{\pi }^{-}{\pi }^{+}$ and $K_S^0{K}^{-}$ final states and present methods to reduce them. We have developed a new approach exploiting a-priori knowledge of signal continuity over adjacent final-state-mass bins to stably fit a large pool of partial-waves to our data, allowing a clean identification of very small signals in our large data sets. For two-body final states of scalar particles, such as $K_S^0{K}^{-}$, mathematical ambiguities in the partial-wave decomposition lead to the same intensity distribution for different combinations of amplitude values. We will discuss these ambiguities and present solutions to resolve or at least reduce the number of possible solutions. Resolving these issues will allow for a complementary analysis of the $a_J$-like resonance sector in these two final states.

    ↳ hep-exhep-phNuovo Cim.C(2024)·3 citations
27. 27*

    Improved Planck constraints on axion-like early dark energy as a resolution of the Hubble tension

    George Efstathiou🇬🇧 · Erik Rosenberg🇬🇧 · Vivian Poulin🇫🇷

    Axion-like early dark energy (EDE) as an extension to $\Lambda$CDM has been proposed as a possible solution to the 'Hubble tension'. We revisit this model using a new cosmic microwave background (CMB) temperature and polarization likelihood constructed from the {\it Planck} NPIPE data release. In a Bayesian analysis, we find that the maximum fractional contribution of EDE to the total energy density is $f_{\mathrm{EDE}}<0.061$ (without SH0ES) over the redshift range $z\in [10^3,10^4]$ and that the Hubble constant is constrained to lie within the range $66.9<H_0<69.5$ km/s/Mpc (both at 95 \% C.L.). The data therefore favour a model close to $\Lambda$CDM, leaving a residual tension of $3.7\sigma$ with the SH$0$ES Cepheid-based measurement of $H_0$. A comparison with the likelihood profile shows that our conclusions are robust to prior-volume effects. Our new CMB likelihood provides no evidence in favour of a significant EDE component.

    ↳ astro-ph.COhep-phPRL(2024)·88 citations
28. 28*

    (Multi-field) Natural Inflation and Gravitational Waves

    Alberto Salvio🇮🇹 · Simone Sciusco🇮🇹

    We provide a detailed study of natural inflation with a periodic non-minimal coupling, which is a well-motivated inflationary model that admits an explicit UV completion. We demonstrate that this construction can satisfy the most recent observational constraints from Planck and the BICEP/Keck collaborations. We also compute the corresponding relic gravitational wave background due to tensor perturbations and show that future space-borne interferometers, such as DECIGO, BBO and ALIA, may be able to detect it. Next, we extend this analysis and establish the validity of these results in a multi-field model featuring an additional $R^2$ term in the action, which allows us to interpolate between natural and scalaron (a.k.a.~Starobinsky) inflation. We investigate the conditions under which the aforementioned future interferometers will have the capability to differentiate between pure natural inflation and natural-scalaron inflation. The latter analysis could open the door to distinguishing between single-field and multi-field inflation through gravitational wave observations in more general contexts.

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2024)·12 citations
29. 29*

    Rogue worlds meet the dark side: revealing terrestrial-mass primordial black holes with the Nancy Grace Roman Space Telescope

    William DeRocco🇺🇸 · Evan Frangipane🇺🇸 · Nick Hamer🇺🇸 · Stefano Profumo🇺🇸 · Nolan Smyth🇺🇸

    Gravitational microlensing is one of the strongest observational techniques to observe non-luminous astrophysical bodies. Existing microlensing observations provide tantalizing evidence of a population of low-mass objects whose origin is unknown. These events may be caused by terrestrial-mass free-floating planets or by exotic objects such as primordial black holes. However, the nature of these objects cannot be resolved on an event-by-event basis, as the induced light curve is degenerate for lensing bodies of identical mass. One must instead statistically compare \textit{distributions} of lensing events to determine the nature of the lensing population. While existing surveys lack the statistics required to identify multiple subpopulations of lenses, this will change with the launch of the Nancy Grace Roman Space Telescope. Roman's Galactic Bulge Time Domain Survey is expected to observe hundreds of low-mass microlensing events, enabling a robust statistical characterization of this population. In this paper, we show that by exploiting features in the distribution of lensing event durations, Roman will be sensitive to a subpopulation of primordial black holes hidden amongst a background of free-floating planets. Roman's reach will extend to primordial black hole dark matter fractions as low as $f_{\text{PBH}}=10^{-4}$ at peak sensitivity, and will be able to conclusively determine the origin of existing ultrashort-timescale microlensing events. A positive detection would provide evidence that a significant fraction of the cosmological dark matter consists of macroscopic, non-luminous objects.

    ↳ astro-ph.COastro-ph.EPastro-ph.GAhep-phPRD(2024)·34 citations

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