Mon·Jul 27, 2020Monday·July 27, 2020

1. 01*

   On next to soft threshold corrections to DIS and SIA processes

   A.H. Ajjath · Pooja Mukherjee🇮🇳 · V. Ravindran🇮🇳 · Aparna Sankar🇮🇳 · Surabhi Tiwari🇮🇳

   We study the perturbative structure of threshold enhanced logarithms in the coefficient functions of deep inelastic scattering (DIS) and semi-inclusive $e^{+}{e}^{-}$ annihilation (SIA) processes and setup a framework to sum them up to all orders in perturbation theory. Threshold logarithms show up as the distributions $((1-z{)}^{-1}{\log }^i(1-z){)}_{+}$ from the soft plus virtual (SV) and as logarithms ${\log }^i(1-z)$ from next to SV (NSV) contributions. We use the Sudakov differential and the renormalisation group equations along with the factorisation properties of parton level cross sections to obtain the resummed result which predicts SV as well as next to SV contributions to all orders in strong coupling constant. In Mellin $N$ space, we resum the large logarithms of the form ${\log }^i(N)$ keeping $1/N$ corrections. In particular, the towers of logarithms, each of the form $a_s^n/N^{\alpha }{\log }^{2n-\alpha }(N),a_s^n/N^{\alpha }{\log }^{2n-1-\alpha }(N)\cdots$ etc for $\alpha =0,1$, are summed to all orders in $a_s$.

   hep-phJHEP(2021)·41 citations
2. 02*

   Multibody decay analyses -- a new phenomenological model for meson-meson subamplitudes

   P.C. Magalhães🇬🇧 · A.C. dos Reis🇧🇷 · M.R. Robilotta🇧🇷

   Meson-meson amplitudes are important on their own and also play key roles in analyses of heavy-meson and tau decays. In this work we propose a new phenomenological model suited to all $SU(3)$ mesonic two-body final state interactions up to energies around 2 GeV. It is aimed at replacing those entering the old isobar model, produced in the 1960's, long before the development of QCD. The only similarity between our new proposal and amplitudes used in the isobar model concern vector resonances in the elastic regime. In other situations, especially those involving scalar resonances and coupled channels, the isobar model is not compatible with post-QCD dynamics. In order to support these claims convincingly and to motivate our approach, we consider applications to the $\pi \pi$ amplitude and compare our version with the isobar model in several different instances. We also show that the new model provides a clear indication of the mechanism responsible for the sharp rise observed in the $\pi \pi$ phase around $1$ GeV. The phenomenological amplitudes proposed here are suited to any number of resonances in a given channel and rely just on masses and coupling constants as free parameters. Concerning theory, they incorporate chiral symmetry at low energies, include coupled channels and respect unitarity whenever appropriate.

   hep-phhep-exPRD(2020)·9 citations
3. 03*

   Stimulated Radiation from Axion Cluster Evolution in Static Spacetimes

   Liang Chen🇺🇸 · Thomas W. Kephart🇺🇸

   If their number density is high enough, clusters of axions can decay to photons via stimulated emission. We study both the special and general relativistic corrections to lasing in such dense axion clusters as they evolve in static spacetimes. Our main results are rate equations for the evolution of axion and photon number densities that include these corrections. We use Schwarzschild spacetime as a detailed example.

   hep-phgr-qcJCAP(2021)·4 citations
4. 04*

   The cross section of $e^{+}{e}^{-}\to \Lambda \overline{\Sigma }{}^0+c.c.$ as a litmus test of isospin violation in the decays of vector charmonia into $\Lambda \overline{\Sigma }{}^0+c.c.$

   Rinaldo Baldini Ferroli🇮🇹 · Alessio Mangoni🇮🇹 · Simone Pacetti🇮🇹

   Under the aegis of isospin conservation, the amplitudes in Born approximation, i.e., considering the only one-photon-exchange mechanism, of the decay $\psi \to \Lambda \overline{\Sigma }{}^0+c.c.$, where $\psi$ is a vector charmonium, and of the reaction $e^{+}{e}^{-}\to \Lambda \overline{\Sigma }{}^0+c.c.$ at the $\psi$ mass, are parametrized by the same electromagnetic coupling. It follows that, the modulus of such a coupling can be extracted the data on the two observables: the decay branching fraction and the annihilation cross section. By considering the first two vector charmonia, $J/\psi$ and $\psi (2S)$, it is found that, especially in the case of $\psi (2S)$, there is a substantial discrepancy between the values of the modulus of the same electromagnetic coupling extracted from the branching ratio and the cross section. We propose, as a possible explanation for such a disagreement, the presence in the decay amplitude of an isospin-violating contribution driven by a mechanism based on physical (on-shell) intermediate states, that, due to their own nature, should be more effective in the $\psi (2S)$ decay than in that of the $J/\psi$.

   hep-phEPJC(2020)·10 citations
5. 05*

   On transverse momenta and (pseudo)rapidity spectrum of the top quark in proton-proton collisions at 13 TeV

   Li-Na Gao🇨🇳 · Er-Qin Wang🇨🇳

   We study the transverse momenta and (pseudo)rapidity spectrum of the top quark and their decay products, the tt-system, and the total number of jets in proton-proton (pp) collisions at 13 TeV by using the Tsallis-Pareto-type function and the three-source Landau hydrodynamic model, respectively. The related parameters, such as the effective temperature of the interacting system (T), the non-extensivity of the process (n) and the width ($\sigma$) of (pseudo)rapidity distribution are extracted.

   hep-ph0 citations
6. 06*

   A theoretical analysis of the semileptonic decays ${\eta }^{(\prime )}\to {\pi }^0{l}^{+}{l}^{-}$ and ${\eta }^{\prime }\to \eta l^{+}{l}^{-}$

   Rafel Escribano🇪🇸 · Emilio Royo🇪🇸

   A complete theoretical analysis of the $C$-conserving semileptonic decays ${\eta }^{(\prime )}\to {\pi }^0{l}^{+}{l}^{-}$ and ${\eta }^{\prime }\to \eta l^{+}{l}^{-}$ ($l=e$ or $\mu$) is carried out within the framework of the Vector Meson Dominance (VMD) model. An existing phenomenological model is used to parametrise the VMD coupling constants and the associated numerical values are obtained from an optimisation fit to $V\to P\gamma$ and $P\to V\gamma$ radiative decays ($V={\rho }^0$, $\omega$, $\varphi$ and $P={\pi }^0$, $\eta$, ${\eta }^{\prime }$). The decay widths and dilepton energy spectra for the two $\eta \to {\pi }^0{l}^{+}{l}^{-}$ processes obtained using this approach are compared and found to be in good agreement with other results available in the published literature. Theoretical predictions for the four ${\eta }^{\prime }\to {\pi }^0{l}^{+}{l}^{-}$ and ${\eta }^{\prime }\to \eta l^{+}{l}^{-}$ decay widths and dilepton energy spectra are calculated and presented for the first time in this work.

   hep-phhep-exnucl-thEPJC(2020)·23 citations
7. 07*

   Hidden Photon Dark Matter Interacting via Axion-like Particles

   Paola Arias🇨🇱 · Ariel Arza🇷🇺 · Joerg Jaeckel🇩🇪 · Diego Vargas-Arancibia🇨🇱

   We investigate a scenario where the dark matter of the Universe is made from very light hidden photons transforming under a $Z_2$-symmetry. In contrast to the usual situation, kinetic mixing is forbidden by the symmetry and the dark photon interacts with the Standard Model photon only via an axion-like particle acting as a "messenger". Focusing on signatures involving the ordinary photon, our survey of the phenomenology includes limits from cosmological stability, CMB distortions, astrophysical energy loss, light-shining-through-walls experiments, helioscopes and solar X-ray observations.

   hep-phastro-ph.COJCAP(2021)·33 citations
8. 08*

   ${\bar{B}}_c\to {\eta }_c$, ${\bar{B}}_c\to J/\psi$ and $\bar{B}\to D^{(\ast )}$ semileptonic decays including new physics

   N. Penalva🇪🇸 · E. Hernández🇪🇸 · J. Nieves🇪🇸

   We apply the general formalism derived in N. Penalva et al. [Phys. Rev. D 101, 113004 (2020)] to the semileptonic decay of pseudoscalar mesons containing a $b$ quark. While present $B\to D^{(\ast )}$ data give the strongest evidence in favor of lepton flavor universality violation, the observables that are normally considered are not able to distinguish between different new physics (NP) scenarios. In the above reference we discussed the relevant role that the various contributions to the double differential decay widths $d^2\Gamma /(d\omega d\cos {\theta }_{\ell })$ and $d^2\Gamma /(d\omega d{E}_{\ell })$ could play to this end. Here $\omega$ is the product of the two hadron four-velocities, ${\theta }_{\ell }$ is the angle made by the final lepton and final hadron three-momenta in the center of mass of the final two-lepton system, and $E_{\ell }$ is the final charged lepton energy in the laboratory system. The formalism was applied there to the analysis of the ${\Lambda }_b\to {\Lambda }_c$ semileptonic decay showing the new observables were able to tell apart different NP scenarios. Here we analyze the ${\bar{B}}_c\to {\eta }_c\tau {\bar{\nu }}_{\tau }$, ${\bar{B}}_c\to J/\psi \tau {\bar{\nu }}_{\tau }$, $\bar{B}\to D\tau {\bar{\nu }}_{\tau }$ and $\bar{B}\to D^{\ast }\tau {\bar{\nu }}_{\tau }$ semileptonic decays. We show that, as a general rule, the ${\bar{B}}_c\to J/\psi$ observables, even including $\tau$ polarization, are less optimal for distinguishing between NP scenarios than those obtained from ${\bar{B}}_c\to {\eta }_c$ decays, or those presented in N. Penalva et al. for the related ${\Lambda }_b\to {\Lambda }_c$ semileptonic decay. Finally, we show that $\bar{B}\to D$ and ${\bar{B}}_c\to {\eta }_c$, and $\bar{B}\to D^{\ast }$ and ${\bar{B}}_c\to J/\psi$ decay observables exhibit similar behaviors.

   hep-phhep-exPRD(2020)·14 citations
9. 09*

   Pseudoscalar and vector open-charm mesons at finite temperature

   Glòria Montaña🇪🇸 · Àngels Ramos🇪🇸 · Laura Tolos🇩🇪 · Juan M. Torres-Rincon🇩🇪

   Vacuum and thermal properties of pseudoscalar and vector charm mesons are analyzed within a self-consistent many-body approach, employing a chiral effective field theory that incorporates heavy-quark spin symmetry. Upon unitarization of the vacuum interaction amplitudes for the scattering of charm mesons off light mesons in a fully coupled-channel basis, new dynamically generated states are searched. The imaginary-time formalism is employed to extend the calculation to finite temperatures up to $T=150$ MeV. Medium-modified spectral shapes of the $D$, $D^{\ast }$, $D_s$ and $D_s^{\ast }$ mesons are provided. The temperature dependence of the masses and decay widths of the nonstrange $D_0^{\ast }$ (2300) and $D_1^{\ast }$(2430) mesons, both showing a double-pole structure in the complex-energy plane, is also reported, as well as that of the $D_{s0}^{\ast }$(2317) and $D_{s1}^{\ast }$(2460) resonances and other states not yet identified experimentally. Being the first calculation incorporating open-charm vector mesons at finite temperature in a self-consistent fashion, it brings up the opportunity to discuss the medium effects on the open charm sector under the perspective of chiral and heavy-quark spin symmetries.

   hep-phnucl-thPRD(2020)·29 citations
10. 10*

    RooHammerModel: interfacing the HAMMER software tool with the HistFactory package

    J. García Pardiñas🇨🇭 · S. Meloni🇮🇹 · L. Grillo🇬🇧 · P. Owen🇨🇭 · M. Calvi🇮🇹 · N. Serra🇨🇭

    Recent $B$-physics results have sparkled great interest in the search for beyond-the-Standard-Model (BSM) physics in $b\to c\ell \bar{\nu }$ transitions. The need to analyse in a consistent manner big datasets for these searches, using high-statistics Monte-Carlo (MC) samples, led to the development of HAMMER, a software tool which enables to perform a fast morphing of MC-derived templates to include BSM effects and/or alternative parameterisations of long-distance effects, avoiding the need to re-generate simulated samples. This paper describes the development of RooHammerModel, an interface between this tool and the commonly-used data-fitting frameworks HistFactory and RooFit. In this document, the structure and functionality of the user interface are explained. Information of a public repository where it can be accessed is provided, as well as validation and performance studies of the interface. The methods developed in the construction of RooHammerModel can provide useful information for alternative future attempts to interface HAMMER with other data-fitting frameworks.

    hep-phJINST(2022)·15 citations
11. 11*

    Axion quality from the (anti)symmetric of SU(N)

    Marco Ardu🇮🇹 · Luca Di Luzio🇩🇪 · Giacomo Landini🇮🇹 · Alessandro Strumia🇮🇹 · Daniele Teresi🇮🇹 · Jin-Wei Wang🇮🇹

    We propose two models where a U(1) Peccei-Quinn global symmetry arises accidentally and is respected up to high-dimensional operators, so that the axion solution to the strong CP problem is successful even in the presence of Planck-suppressed operators. One model is SU$(N)$ gauge interactions with fermions in the fundamental and a scalar in the symmetric. The axion arises from spontaneous symmetry breaking to SO$(N)$, that confines at a lower energy scale. Axion quality in the model needs $N\gtrsim 10$. SO bound states and possibly monopoles provide extra Dark Matter candidates beyond the axion. In the second model the scalar is in the anti-symmetric: SU$(N)$ broken to Sp$(N)$ needs even $N\gtrsim 20$. The cosmological DM abundance, consisting of axions and/or super-heavy relics, can be reproduced if the PQ symmetry is broken before inflation (Boltzmann-suppressed production of super-heavy relics) or after (super-heavy relics in thermal equilibrium get partially diluted by dark glue-ball decays).

    hep-phastro-ph.COhep-thJHEP(2020)·62 citations
12. 12*

    Quantum breaks in a model for the evolution of neutrinos during their decoupling era in the big bang

    R. F. Sawyer🇺🇸

    An active two-neutrino state's coupling to an intermediate scalar meson, and thence to a two-antineutrino state, is one idea for catalyzing transitions from active to sterile neutrinos, in an implementation of the Dodelson-Widrow proposal for the production of sterile and somewhat massive neutrinos as dark matter candidates. We propose some mechanics that promises to use the very same model with the same mass and coupling parameters, in order to achieve similar results, but orders of magnitude faster; or alternatively, similar results but beginning with vastly reduced coupling constants. The model then would become much less constrained by consistency with laboratory and astrophysical data.

    hep-ph3 citations
13. 13*

    CKM Substructure

    Yuval Grossman🇺🇸 · Joshua T. Ruderman🇺🇸

    The CKM matrix is not generic. The Wolfenstein parametrization encodes structure by having one small parameter, $\lambda \approx 0.22$. We pose the question: is there substructure in the CKM matrix that goes beyond the single small parameter of the Wolfenstein parameterization? We find two relations that are approximately satisfied: $|V_{td}{|}^2=|V_{cb}{|}^3$ and $|V_{ub}{|}^2|V_{us}|=|V_{cb}{|}^4$. We discuss the statistical significance of these relations and find that they may indicate deeper structure in the CKM matrix. The current precision, however, cannot exclude an $\mathcal{O}(10\%)$ accident.

    hep-phJHEP(2021)·7 citations
14. 14*

    Hadronic vacuum polarization and vector-meson resonance parameters from $e^{+}{e}^{-}\to {\pi }^0\gamma$

    Bai-Long Hoid🇩🇪 · Martin Hoferichter🇨🇭 · Bastian Kubis🇩🇪

    We study the reaction $e^{+}{e}^{-}\to {\pi }^0\gamma$ based on a dispersive representation of the underlying ${\pi }^0\to \gamma {\gamma }^{\ast }$ transition form factor. As a first application, we evaluate the contribution of the ${\pi }^0\gamma$ channel to the hadronic-vacuum-polarization correction to the anomalous magnetic moment of the muon. We find $a_{\mu }^{{\pi }^0\gamma }{|}_{\le 1.35\text{GeV}}=43.8(6)\times 10^{-11}$, in line with evaluations from the direct integration of the data. Second, our fit determines the resonance parameters of $\omega$ and $\varphi$. We observe good agreement with the $e^{+}{e}^{-}\to 3\pi$ channel, explaining a previous tension in the $\omega$ mass between ${\pi }^0\gamma$ and $3\pi$ by an unphysical phase in the fit function. Combining both channels we find ${\bar{M}}_{\omega }=782.736(24)\text{MeV}$ and ${\bar{M}}_{\varphi }=1019.457(20)\text{MeV}$ for the masses including vacuum-polarization corrections. The $\varphi$ mass agrees perfectly with the PDG average, which is dominated by determinations from the $\bar{K}K$ channel, demonstrating consistency with $3\pi$ and ${\pi }^0\gamma$. For the $\omega$ mass, our result is consistent but more precise, exacerbating tensions with the $\omega$ mass extracted via isospin-breaking effects from the $2\pi$ channel.

    hep-phhep-exhep-latnucl-thEPJC(2020)·107 citations
15. 15*

    Shift-Type SMEFT Effects in Dileptons at the LHC

    Alyssa Horne🇺🇸 · Jordan Pittman🇺🇸 · Marcus Snedeker🇺🇸 · William Shepherd🇺🇸 · Joel W. Walker🇺🇸

    We explore the constraints which can be derived on Wilson coefficients in the Standard Model Effective Field Theory from dilepton production, notably including the constraints on operators which do not lead to cross sections growing with energy relative to the Standard Model rate, i.e. shifts. We incorporate essential theory error estimates from higher EFT orders in the analysis in order to provide robust bounds. We find that constraints on four-fermion operator contributions which do grow with energy are not materially weakened by the inclusion of these shifts, and that a constraint on the shifts can also be derived, with a characteristic strength comparable to, and a directionality in parameter space complementary to, those from LEP data. This completes the study of hadronically-quiet dilepton production in the SMEFT, and provides two new constraints which are linearly independent from others arising at the LHC and also rotated in Wilson coefficient space relative to, though not completely independent from, the LEP bounds.

    hep-phJHEP(2021)·12 citations
16. 16*

    PyR@TE 3

    Lohan Sartore🇫🇷 · Ingo Schienbein🇫🇷

    We present a new version of PyR@TE, a Python tool for the computation of renormalization group equations for general, non-supersymmetric gauge theories. Its new core relies on a recent paper by Poole & Thomsen (arXiv:1906.04625) to compute the $\beta$-functions. In this framework, gauge kinetic mixing is naturally implemented, and the Weyl consistency relations between gauge, quartic and Yukawa couplings are automatically satisfied. One of the main new features is the possibility for the user to compute the gauge coupling $\beta$-functions up to the three-loop order. Large parts of the PyR@TE code have been rewritten and improved, including the group theory module PyLie. As a result, the overall performance in terms of computation speed was drastically improved and the model file is more flexible and user-friendly.

    hep-phComput.Phys.Commun.(2021)·95 citations
17. 17*

    A new approach to modelling elastic and inelastic photon-initiated production at the LHC: SuperChic 4

    L.A. Harland-Lang🇬🇧 · M. Tasevsky🇨🇿 · V.A. Khoze🇬🇧 · M.G. Ryskin🇷🇺

    We present the results of the new SuperChic 4 Monte Carlo implementation of photon-initiated production in proton-proton collisions, considering as a first example the case of lepton pair production. This is based on the structure function calculation of the underlying process, and focusses on a complete account of the various contributing channels, including the case where a rapidity gap veto is imposed. We provide a careful treatment of the contributions where either (single dissociation), both (double dissociation) or neither (elastic) proton interacts inelastically and dissociates, and interface our results to Pythia for showering and hadronization. The particle decay distribution from dissociation system, as well the survival probability for no additional proton-proton interactions, are both fully accounted for; these are essential for comparing to data where a rapidity gap veto is applied. We present detailed results for the impact of the veto requirement on the differential cross section, compare to and find good agreement with ATLAS 7 TeV data on semi-exclusive production, and provide a new precise evaluation of the background from semi-exclusive lepton pair production to SUSY particle production in compressed mass scenarios, which is found to be low.

    hep-phhep-exEPJC(2020)·105 citations
18. 18*

    Sterile Neutrino Dark Matter and Leptogenesis in Left-Right Higgs Parity

    David Dunsky🇺🇸 · Lawrence J. Hall🇺🇸 · Keisuke Harigaya🇺🇸

    The standard model Higgs quartic coupling vanishes at $(10^9-10^{13})$ GeV. We study $SU(2{)}_L\times SU(2{)}_R\times U(1{)}_{B-L}$ theories that incorporate the Higgs Parity mechanism, where this becomes the scale of Left-Right symmetry breaking, $v_R$. Furthermore, these theories solve the strong CP problem and predict three right-handed neutrinos. We introduce cosmologies where $SU(2{)}_R\times U(1{)}_{B-L}$ gauge interactions produce right-handed neutrinos via the freeze-out or freeze-in mechanisms. In both cases, we find the parameter space where the lightest right-handed neutrino is dark matter and the decay of a heavier one creates the baryon asymmetry of the universe via leptogenesis. A theory of flavor is constructed that naturally accounts for the lightness and stability of the right-handed neutrino dark matter, while maintaining sufficient baryon asymmetry. The dark matter abundance and successful natural leptogenesis require $v_R$ to be in the range $(10^{10}-10^{13})$ GeV for freeze-out, in remarkable agreement with the scale where the Higgs quartic coupling vanishes, whereas freeze-in requires $v_R\gtrsim 10^9$ GeV. The allowed parameter space can be probed by the warmness of dark matter, precise determinations of the top quark mass and QCD coupling by future colliders and lattice computations, and measurement of the neutrino mass hierarchy.

    hep-phastro-ph.COhep-exJHEP(2021)·29 citations
19. 19*

    Constraints on Dynamical Dark Energy Models from the Abundance of Massive Galaxies at High Redshifts

    N. Menci🇮🇹 · A. Grazian🇮🇹 · M. Castellano🇮🇹 · P. Santini🇮🇹 · E. Giallongo🇮🇹 · A. Lamastra🇮🇹 · F. Fortuni🇮🇹 · A. Fontana🇮🇹 · E. Merlin🇮🇹 · T. Wang🇯🇵 · D. Elbaz🇫🇷 · N.G. Sanchez🇫🇷

    We compare the maximal abundance of massive systems predicted in different dynamical dark energy (DDE) models at high redshifts z = 4-7 with the measured abundance of the most massive galaxies observed to be already in place at such redshifts. The aim is to derive constraints for the evolution of the dark energy equation of state parameter w which are complementary to existing probes. We adopt the standard parametrization for the DDE evolution in terms of the local value w_0 and of the look-back time derivative w_a of the equation of state. We derive constraints on combinations (w_0, w_a) in the different DDE models by using three different, independent probes: (i) the observed stellar mass function of massive objects at z = 6 derived from the CANDELS survey; (ii) the estimated volume density of massive halos derived from the observation of massive, star-forming galaxies detected in the submillimeter range at z = 4; (iii) The rareness of he most massive system (estimated gas mass exceeding 3 10^11 M_sun) observed to be in place at z = 7, a far-infrared-luminous object recently detected in the South Pole Telescope (SPT) survey. Finally, we show that the combination of our results from the three above probes excludes a sizable fraction of the DDE parameter space w_a > -3/4 - (w_0 + 3/2) presently allowed (or even favored) by existing probes.

    ↳ astro-ph.COastro-ph.GAgr-qchep-phApJ(2020)·20 citations
20. 20*

    Subaru through a different lens: microlensing by extended dark matter structures

    Djuna Croon🇨🇦 · David McKeen🇨🇦 · Nirmal Raj🇨🇦 · Zihui Wang🇺🇸

    We investigate gravitational microlensing signals produced by a spatially extended object transiting in front of a finite-sized source star. The most interesting features arise for lens and source sizes comparable to the Einstein radius of the setup. Using this information, we obtain constraints from the Subaru-HSC survey of M31 on the dark matter populations of NFW subhalos and boson stars of asteroid to Earth masses. These lens profiles capture the qualitative behavior of a wide range of dark matter substructures. We find that deviations from constraints on point-like lenses (e.g. primordial black holes and MACHOs) become visible for lenses of radius 0.1 $R_{\odot }$ and larger, with the upper bound on lens masses weakening with increasing lens size.

    ↳ astro-ph.COhep-phPRD(2020)·161 citations
21. 21*

    Strong bound on canonical ultra-light axion dark matter from the Lyman-alpha forest

    Keir K. Rogers🇸🇪 · Hiranya V. Peiris🇬🇧

    We present a new bound on the ultra-light axion (ULA) dark matter mass $m_{\text{a}}$, using the Lyman-alpha forest to look for suppressed cosmic structure growth: a 95% lower limit $m_{\text{a}}>2\times 10^{-20}\text{eV}$. This strongly disfavors ($>99.7\%$ credibility) the canonical ULA with $10^{-22}\text{eV}<m_{\text{a}}<10^{-21}\text{eV}$, motivated by the string axiverse and solutions to possible tensions in the cold dark matter model. We strengthen previous equivalent bounds by about an order of magnitude. We demonstrate the robustness of our results using an optimized emulator of improved hydrodynamical simulations.

    ↳ astro-ph.COhep-phPRL(2021)·412 citations
22. 22*

    Revisiting AGN as the Source of IceCube's Diffuse Neutrino Flux

    Daniel Smith🇺🇸 · Dan Hooper🇺🇸 · Abigail Vieregg🇺🇸

    The origin of the astrophysical neutrino flux reported by the IceCube Collaboration remains an open question. In this study, we use three years of publicly available IceCube data to search for evidence of neutrino emission from the blazars and non-blazar Active Galactic Nuclei (AGN) contained the Fermi 4LAC catalog. We find no evidence that these sources produce high-energy neutrinos, and conclude that blazars can produce no more than 15% of IceCube's observed flux. The constraint we derive on the contribution from non-blazar AGN, which are less luminous and more numerous than blazars, is significantly less restrictive, and it remains possible that this class of sources could produce the entirety of the diffuse neutrino flux observed by IceCube. We anticipate that it will become possible to definitively test such scenarios as IceCube accumulates and releases more data, and as gamma-ray catalogs of AGN become increasingly complete. We also comment on starburst and other starforming galaxies, and conclude that these sources could contribute substantially to the signal observed by IceCube, in particular at the lowest detected energies.

    ↳ astro-ph.HEastro-ph.COhep-phJCAP(2021)·49 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.