Fri·Jan 20, 2023Friday·January 20, 2023

1. 01*

   Nucleon Resonance Electroexcitation Amplitudes and Emergent Hadron Mass

   Daniel S. Carman🇺🇸 · Ralf W. Gothe🇺🇸 · Victor I. Mokeev🇺🇸 · Craig D. Roberts🇨🇳

   Understanding the strong interaction dynamics that govern the emergence of hadron mass (EHM) represents a challenging open problem in the Standard Model. In this paper we describe new opportunities for gaining insight into EHM from results on nucleon resonance ($N^{\ast }$) electroexcitation amplitudes (i.e. ${\gamma }_{v}p{N}^{\ast }$ electrocouplings) in the mass range up to 1.8\,GeV for virtual photon four-momentum squared (i.e. photon virtualities $Q^2$) up to 7.5\,GeV${}^2$ available from exclusive meson electroproduction data acquired during the 6-GeV era of experiments at Jefferson Laboratory (JLab). These results, combined with achievements in the use of continuum Schwinger function methods (CSMs), offer new opportunities for charting the momentum dependence of the dressed quark mass from results on the $Q^2$-evolution of the ${\gamma }_{v}p{N}^{\ast }$ electrocouplings. A successful description of the $\Delta (1232)3/2^{+}$ and $N(1440)1/2^{+}$ electrocouplings has been achieved using CSMs with, in both cases, common momentum-dependent mass functions for the dressed quarks, for the gluons, and the same momentum-dependent strong coupling. Parameter-free CSM predictions for the electrocouplings of the $\Delta (1600)3/2^{+}$ became available in 2019. The experimental results obtained in the first half of 2022 have confirmed the CSM predictions. We also discuss prospects for these studies during the 12-GeV era at JLab using the CLAS12 detector, with experiments that are currently in progress, and canvass the physics motivation for continued studies in this area with a possible increase of the JLab electron beam energy up to 22\,GeV.

   hep-phnucl-exnucl-thParticles(2023)·46 citations
2. 02*

   Non-perturbative strong coupling at timelike momenta

   Jan Horak🇩🇪 · Jan M. Pawlowski🇩🇪 · Jonas Turnwald🇩🇪 · Julian M. Urban🇺🇸 · Nicolas Wink🇩🇪 · Savvas Zafeiropoulos🇫🇷

   We compute the strong coupling constant of Landau gauge QCD in the full complex momentum plane, both directly and via spectral reconstruction. In particular, we consider the Taylor coupling given by the product of ghost and gluon dressing functions. Assuming spectral representations for the latter, we first show that also the coupling obeys such a representation. The subsequent spectral reconstruction of the coupling data, obtained from 2+1 flavour lattice QCD results for the ghost and gluon, is based on a probabilistic inversion of this representation using Gaussian process regression with analytically enforced asymptotics. In contradistinction, our direct calculation relies on earlier reconstruction results for the ghost and gluon spectral functions themselves, as well as data obtained in functional QCD. Apart from its relevance for studies of resonances or scattering processes, the calculation also serves as a non-trivial benchmark of our reconstruction approach. The results show remarkable agreement, testifying to the reliability of the method.

   hep-phhep-latPRD(2023)·30 citations
3. 03*

   Fermion masses and mixings and $g-2$ muon anomaly in a $Q_6$ flavored 2HDM

   V. V. Vien🇻🇳 · H. N. Long · A. E. Cárcamo Hernández🇨🇱 · Juan Marchant González🇨🇱

   We propose an extended 2HDM with $Q_6\times Z_4\times Z_2$ symmetry that can successfully accommodate the SM fermion mass and mixing hierarchy. The tiny masses of the active neutrinos are generated from a type-I seesaw mechanism mediated by very heavy right-handed Majorana neutrinos. The model gives a natural explanation of the charged lepton mass hierarchy. Besides that, the experimental values of the physical observables of the neutrino sector: the neutrino mass squared splittings, the leptonic mixing angles and the leptonic Dirac CP violating phase, are also successfully reproduced for both normal and inverted neutrino mass hierarchies. We find a feasible range of values for the leptonic Dirac CP phase to be in the ranges ${\delta }_{CP}\in (305.90,348.70{)}^{\circ }$ for normal ordering and ${\delta }_{CP}\in (308.00,348.00{)}^{\circ }$ for inverted ordering, which is consistent with the 3$\sigma$ experimentally allowed limits. The sum of neutrino masses is obtained as $\sum m_i\in (58.03,60.51)$ meV for normal ordering and $\sum m_i\in (98.07,101.40)$ meV for inverted ordering which are well consistent with all the recent limits. In addition, the obtained ranges for the effective neutrino masses are $⟨m_{ee}⟩\in (3.80,4.38)$\, meV, $m_{\beta }\in (8.53,9.34)\text{mbox}meV$ for normal ordering and $⟨m_{ee}⟩\in (47.85,49.58)$ meV, $m_{\beta }\in (48.39,50.09)\text{mbox}meV$ for inverted ordering which are in agreement with the recent experimental bounds. For the quark sector, the derived results are also in agreement with the recent data on the quark masses and mixing angles. The model under consideration can also accommodate the muon anomalous magnetic moment.

   hep-phNPB(2024)·4 citations
4. 04*

   Single Higgs Boson Production at Electron-Positron Colliders in Gauge-Higgs Unification

   Shuichiro Funatsu🇯🇵 · Hisaki Hatanaka🇯🇵 · Yuta Orikasa🇨🇿 · Naoki Yamatsu🇹🇼

   We examine contributions to single Higgs boson production processes via $Z^{\prime }$ and $W^{\prime }$ bosons in the $SU(3{)}_C\times SO(5{)}_W\times U(1{)}_X$ gauge-Higgs unification (GHU) model. In particular, we analyze the cross sections of three single Higgs boson production processes $e^{-}{e}^{+}\to Zh$, $e^{-}{e}^{+}\to \nu \bar{\nu }h$, and $e^{-}{e}^{+}\to e^{-}{e}^{+}h$ in the SM and the GHU model. For the Higgs strahlung process $e^{-}{e}^{+}\to Zh$, we show that for a parameter region satisfying the current experimental constraints, a maximum deviation from the SM is about up to 6% for the center-of-mass energy of the initial electron and positron $\sqrt{s}=250$ GeV and that from the SM is about up to 20% for $\sqrt{s}=500$ GeV, depending on the initial polarization of electron and positron. The deviation from the SM is monotonically increasing with respect to $\sqrt{s}$ for $\sqrt{s}\lesssim 1$ TeV. By using the Higgs strahlung process, it is possible to explore up to the region of tens of TeV in terms of the Kaluza-Klein (KK) mass. We also show that the sign of the bulk mass of a lepton multiplet in the GHU model can be determined by examining the deviation of the left-right symmetry of the $e^{-}{e}^{+}\to Zh$ process from the SM. The contributions to the cross sections of the $e^{-}{e}^{+}\to \nu \bar{\nu }h$ and $e^{-}{e}^{+}\to e^{-}{e}^{+}h$ processes via the $Z^{\prime }$ and $W^{\prime }$ bosons are relatively small compared to that for $e^{-}{e}^{+}\to Zh$ at least for $\sqrt{s}\le 1$ TeV. As is the same as in the SM, the $e^{-}{e}^{+}\to \nu \bar{\nu }h$ process gives a main contribution to the single Higgs boson production processes for $\sqrt{s}\gtrsim 500$ GeV, but large deviations from the SM are only observed on energy scales close to the masses of the first KK gauge bosons or higher.

   hep-phPRD(2023)·9 citations
5. 05*

   Three-dimensional QCD phase diagram in the pNJL model

   Lu-Meng Liu🇨🇳 · Jun Xu🇨🇳 · Guang-Xiong Peng🇨🇳

   Based on the three-flavor Polyakov-looped Nambu$-$Jona-Lasinio (pNJL) model, we have studied the structure of the three-dimensional QCD phase diagram with respect to the temperature, the baryon chemical potential, and the isospin chemical potential, by investigating the interplay among the chiral quark condensate, the pion condensate, and the Polyakov loop. While the pNJL model leads to qualitatively similar structure of the normal quark phase, the pion superfluid phase, and the Sarma phase as well as their phase boundaries, when compared to the NJL model, the inclusion of the Polyakov loop enlarges considerably the areas of the pion superfluid phase and the Sarma phase, and leads to critical end points at higher temperatures. With the contribution of the gluon dynamics effectively included, the present study is expected to give a more reliable prediction of the three-dimensional QCD phase diagram compared to that in the NJL model.

   hep-phnucl-thNucl.Phys.Rev.(2023)·7 citations
6. 06*

   Just a MeerKAT, or a dark matter machine?

   Geoff Beck🇿🇦 · Sphesihle Makhathini🇿🇦

   The MeerKAT telescope is a precursor experiment to the full Square Kilometre Array. The latter's potential to explore the nature of dark matter, via indirect detection, has received attention previously in the literature. In this work, we demonstrate the potential of MeerKAT to make initial forays into the dark matter parameter space through a Stimela-based simulation framework. In particular, we show that 20 hr MeerKAT observations at U- and L-band of the dwarf galaxy Reticulum II can improve the constraints on WIMP dark matter by a factor of 3 compared to current gamma-ray observations. Furthermore, these MeerKAT constraints are an order magnitude better than Fermi-LAT estimates from similar galaxies.

   hep-ph5 citations
7. 07*

   Discriminating between Higgs Production Mechanisms via Jet Charge at the LHC

   Hai Tao Li🇨🇳 · Bin Yan🇨🇳 · C. -P. Yuan🇺🇸

   Discriminating the Higgs production mechanisms plays a crucial role in directly measuring the couplings of Higgs to gauge bosons for probing the nature of the electroweak symmetry breaking. We propose a novel method to distinguish the Higgs production mechanisms at the LHC by utilizing the jet charge asymmetry of the two leading forward jets in Higgs plus two jets production. This novel observable provides a way to disentangle the $W$-fusion from the $Z$-fusion and gluon fusion processes for the first time, due to the electric charge correlation of the two leading jets in the events. We show that the Higgs couplings to gauge bosons can be well constrained and its conclusion does not depend on the other possible new physics effects which modify the Higgs total or partial width. We also discuss the complementary roles between the proposed jet charge asymmetry measurement and the Higgs signal strength measurements at the HL-LHC in determining the Higgs couplings.

   hep-phhep-exPRL(2023)·15 citations
8. 08*

   Real effective potentials for phase transitions in models with extended scalar sectors

   Károly Seller🇭🇺 · Zsolt Szép🇭🇺 · Zoltán Trócsanyi🇭🇺

   The effective potential obtained by loop expansion is usually not real in the range of field values explored by its minima during a phase transition. We apply the optimized perturbation theory in a fixed gauge to singlet scalar extensions of the Standard Model in order to calculate a one-loop effective potential that is real by construction. We test this computational scheme by comparing such a potential obtained in Landau gauge to that derived based on the Higgs pole mass. We carry out the latter construction by imposing physical renormalization conditions, which yields a potential without residual regularization scale dependence. We use our effective potential to study the parameter dependence of the critical temperatures in a two-step phase transition of the form $(0,0)\to (0,w^{\prime })\to (v,w)$ that occurs for decreasing temperature in scalar extensions of the SM with two vacuum expectation values $v$ and $w$.

   hep-phJHEP(2023)·7 citations
9. 09*

   On geometrical interpretation of alignment phenomenon

   I. P. Lokhtin🇷🇺 · A. V. Nikolskii🇷🇺 · A. M. Snigirev🇷🇺

   The observed alignment of spots in the x-ray films in cosmic ray emulsion experiments is analyzed and interpreted in the framework of geometrical approach. It is shown that the high degree of alignment can appear partly due to the selection procedure of most energetic particles itself and the threshold on the energy deposition together with the transverse momentum conservation.

   hep-phastro-ph.HEhep-exEPJC(2023)·4 citations
10. 10*

    Probing gluon GTMDs through exclusive coherent diffractive processes

    Daniël Boer🇳🇱 · Chalis Setyadi🇳🇱

    We extend a previous GTMD model to improve the description of the HERA data on diffractive dijet production, and include exclusive coherent diffractive $J/\psi$ production data. We find that within our gluon GTMD model context and assumptions, there is considerable tension between the data for these two types of processes concerning the $t$ dependence. Photo- and electroproduction data for protons and nuclei from EIC and UPC data from LHC and RHIC can help to establish whether a common GTMD description is possible, as one would expect, and to facilitate studies of such data we provide predictions for the various experiments. We point out explicitly in which sense this goes beyond the description in terms of GPDs.

    hep-phhep-exEPJC(2023)·28 citations
11. 11*

    Application of Bayesian statistics to the sector of decay constants in three-flavour ChPT

    Marián Kolesár🇨🇿 · Jaroslav Říha🇨🇿

    The sector of decay constants of the octet of light pseudoscalar mesons in the framework of 'resummed' $SU(3)$ chiral perturbation theory is investigated. A theoretical prediction for the decay constant of $\eta$-meson is compared to a range of available determinations. Compatibility of these determinations with the latest fits of the $SU(3)$ low energy coupling constants is discussed. Using a Bayesian statistical approach, constraints on the low energy coupling constants $L_4^r$ and $L_5^r$, as well as higher order remainders to the decay constants $F_K$ and $F_{\eta }$, are extracted from the most recent experimental and lattice QCD inputs for the values of the decay constants.

    hep-phhep-latEur.Phys.J.Plus(2024)·3 citations
12. 12*

    Traces of the new $a_0(1780)$ resonance in the $J/\psi \to \varphi K^{+}{K}^{-}(K^0{\bar{K}}^0)$ reaction

    Luciano M. Abreu🇧🇷 · Wen-Fei Wang🇨🇳 · Eulogio Oset🇪🇸

    We study the $J/\psi \to \varphi K\bar{K}$ decay, looking for differences in the production rates of $K^{+}{K}^{-}$ or $K^0{\bar{K}}^0$ in the region of 1700-1800 MeV, where two resonances appear dynamically generated from the vector-vector interaction. Two resonances are known experimentally in that region, the $f_0(1710)$ and a new resonance reported by the BABAR and BESIII collaborations. The $K\bar{K}$ should be produced with $I=0$ in that reaction, but due to the different $K^{\ast 0}$ and $K^{\ast +}$ masses some isospin violation appears. Yet, due to the large width of the $K^{\ast }$, the violation obtained is very small and the rates of $K^{+}{K}^{-}$ or $K^0{\bar{K}}^0$ production are equal within $5\%$. However, we also find that due to the step needed to convert two vectors into $K\bar{K}$, a shape can appear in the $K\bar{K}$ mass distribution that can mimic the $a_0$ production around the $K^{\ast }{\bar{K}}^{\ast }$ threshold, and is simply a threshold effect.

    hep-phEPJC(2023)·7 citations
13. 13*

    Relations for low-energy constants in baryon chiral perturbation theory with explicit $\Delta (1232)$ derived from the chiral quark model

    Jun Jiang🇨🇳 · Shao-Zhou Jiang🇨🇳 · Shi-Yuan Li🇨🇳 · Yan-Rui Liu🇨🇳 · Zong-Guo Si🇨🇳 · Hong-Qian Wang🇨🇳

    We study the relations between low-energy constants (LECs) in the chiral Lagrangians with $\Delta (1232)$ and those in the quark-level description model up to the third chiral order. Ten structure correspondences are involved in getting the relations. This situation is more complicated than the spin-1/2 baryon case. The obtained results may help to further investigations involving the $\Delta (1232)$ baryons.

    hep-phhep-latnucl-thEPJC(2023)·3 citations
14. 14*

    Uncertainties on the ${\nu }_{\mu }$/${\nu }_e$, ${\bar{\nu }}_{\mu }$/${\bar{\nu }}_e$ and ${\nu }_e$/${\bar{\nu }}_e$ cross-section ratio from the modelling of nuclear effects and their impact on neutrino oscillation experiments

    T. Dieminger🇨🇭 · S. Dolan🇨🇭 · D. Sgalaberna🇨🇭 · A. Nikolakopoulos🇺🇸 · T. Dealtry🇬🇧 · S. Bolognesi🇫🇷 · L. Pickering🇬🇧 · A. Rubbia🇨🇭

    The potential for mis-modeling of ${\nu }_{\mu }$/${\nu }_e$, ${\bar{\nu }}_{\mu }$/${\bar{\nu }}_e$ and ${\nu }_e$/${\bar{\nu }}_e$ cross section ratios due to nuclear effects is quantified by considering model spread within the full kinematic phase space for CCQE interactions. Its impact is then propagated to simulated experimental configurations based on the Hyper-K and ESS$\nu$SB experiments. Although significant discrepancies between theoretical models is confirmed, it is found that these largely lie in regions of phase space that contribute only a very small portion of the flux integrated cross sections. Overall, a systematic uncertainty on the oscillated flux-averaged ${\nu }_e$/${\bar{\nu }}_e$ cross-section ratio is found to be $\sim$2\% and $\sim$4\% for Hyper-K and ESS$\nu$SB respectively.

    hep-phhep-exPRD(2023)·10 citations
15. 15*

    Neutrino oscillations in vortex and twisting magnetic fields

    O. M. Boyarkin🇧🇾 · I. O. Boyarkina🇮🇹

    The behavior of the neutrino flux in vortex and twisting magnetic fields is considered within the left-right symmetric model. By way of illustration of the magnetic fields we discuss the magnetic fields of the coupled sunspots (CS's) which are the sources of the future solar flares. It is expected that the neutrinos have such multipole moments as the charge radius, the magnetic and anapole moments. The evolution equation in the Schrodinger-like form is found and all magnetic-induced resonance conversions are analyzed. It is demonstrated that in the case of the high-energy flares the sizeable depletion of the ${\nu }_{eL}$ neutrinos caused by their resonance absorptions takes place. Possibilities of observations of this phenomena are investigated at neutrino telescopes whose work is based on the reaction of the coherent elastic neutrino-nucleus scattering.

    hep-ph1 citation
16. 16*

    Pseudoscalar and Vector $T_{QQ\bar{q}{\bar{q}}^{\prime }}$ Spectra and Couplings from LSR at NLO

    R. Albuquerque (FAT, UERJ, Rio de Janeiro, BR)🇧🇷 · S. Narison (LUPM-CNRS, Montpellier, FR and iHEPMAD, Univ. Antananarivo, MG)🇫🇷 · D. Rabetiarivony (iHEPMAD, Univ. Antananarivo, MG)🇲🇬

    We present systematic and improved estimates of the masses and couplings of the $(0^{-})$ and $(1^{-})$ $T_{QQ\bar{q}{\bar{q}}^{\prime }}$ states ($Q=c,b;q,q^{\prime }=u,d,s$) using QCD Laplace sum rules (LSR) and their ratios R within $\tau$ and $t_c$-stabilities criteria complemented by the (rigorous) condition: $R_{P/C}\equiv$ { Pole (Resonance) over the QCD continuum contributions} $\ge 1$. NLO factorized perturbative (PT) QCD corrections are included for giving a meaning on the choice of the used running MS heavy quark mass, while the OPE is truncated at the under-controlled $d=6$ dimension condensates. Our results are compiled in Tables 4,7,10,12 and compared with some LO existing ones. We observe that the icurrents lead to two classes : Class H (Heavy) states with masses around 6 (resp. 13) GeV for charm (resp. bottom) channels. Class L (Light) states $T_{cc\bar{q}{\bar{q}}^{\prime }}(3.8\sim 4.4)$ where the pseudoscalar (resp. all vector states) are below the open charm thresholds and $T_{bb\bar{q}{\bar{q}}^{\prime }}(\simeq 10.4)$ where all of them are below the open beauty thresholds. Mass-splittings due to SU3 breakings are tiny (< 50 MeV). Though more accessible experimentally, Class L states have weaker couplings to the currents than the Class H ones and may be difficult to observe. The mass-splittings between the 1st radial excitation and the ground state are about 2 GeV which are (almost) heavy flavour and current-type independent while their couplings are large signaling new dynamics of these exotic states. Quark masses behaviours of the masses and couplings based on empirical observation are discussed. The eventual findings of the $T_{cc\bar{u}\bar{d}}$(6.3) $0^{-}$ ground state which may not be obscured by the Class L 1st radial excitations can be an alternative way to test the vacuum saturation violation of the four-quark $d=6$ condensates.

    hep-phhep-exhep-latNPA(2023)·14 citations
17. 17*

    Accretion, Evaporation and Superradiance Phase Diagram of (Primordial) Black Holes and $10^{-21}-10^{21}$ eV Scalar, Vector, Tensor Fields

    Caner Unal🇮🇱

    We obtain the accretion, evaporation and superradiance phase diagram of astrophysical and primordial black holes in the mass range $10^{-33}-10^{11}{M}_{\odot }$. This black hole mass range corresponds to production of $10^{-21}-10^{21}$ eV particles for superradiance (bosons) and evaporation (bosons and fermions). Only accretion and superradiance processes are relevant for heavy black holes, on the other hand for light black holes of primordial origin, all three processes can be relevant. We find that superradiance instability can happen even for black hole spin values as low as $10^{-9}-10^{-2}$. Since light black holes are very unstable to these perturbations and sensitive probes of bosonic particles, a single moderately spinning BH can probe 2-9 orders of magnitude of mass parameter space depending on the nature of the perturbations that are scalar (axion), vector (dark photon and/or photon with effective mass) and spin-2. If spinning black holes are observed and superradiance is not observed, possibly due to self-interactions, we find limits on the axion/scalar decay constant and energy density. We generalize these bounds for vector and spin-2 fields.

    hep-phastro-ph.COastro-ph.HEgr-qcPLB(2025)·11 citations
18. 18*

    Near-Extremal Charged Black Holes: Greybody Factors and Evolution

    Yang Bai🇺🇸 · Mrunal Korwar🇺🇸

    As a charged black hole reaches its extremal state via Hawking radiation, quantum effects become important for its thermodynamic properties when its temperature is below a mass gap scale. Using AdS${}_2$/CFT${}_1$ correspondence and solutions for the corresponding Schwarzian action, we calculate the black hole greybody factors including the quantum effects. In the low temperature limit, the greybody factors scale as $T^{2s+3/2}$ with $s$ the radiated field spin. Hence, the Hawking radiation of a near-extremal charged black hole (NEBH) is dominated by emitting scalar particles including the Higgs boson. Time evolution of an NEBH is also calculated and shows a stochastic feature. For an NEBH lighter than around $10^8$ times the Planck mass, its temperature at the current universe is below the mass gap scale and is universally tens of GeV, which is important if one searches for primordial (hidden) charged black holes.

    ↳ hep-thhep-phJHEP(2023)·16 citations
19. 19*

    Nucleon form factors and the pion-nucleon sigma term

    Rajan Gupta🇺🇸 · Tanmoy Bhattacharya🇺🇸 · Vincenzo Cirigliano🇺🇸 · Martin Hoferichter🇨🇭 · Yong-Chull Jang🇺🇸 · Balint Joo🇺🇸 · Emanuele Mereghetti🇺🇸 · Santanu Mondal🇺🇸 · Sungwoo Park🇺🇸 · Frank Winter🇺🇸 · Boram Yoon🇺🇸

    This talk summarizes the progress made since Lattice 2021 in understanding and controlling the contributions of towers of multihadron excited states with mass gaps starting lower than of radial excitations, and in increasing our confidence in the extraction of ground state nucleon matrix elements. The most clear evidence for multihadron excited state contributions (ESC) is in axial/pseudoscalar form factors that are required to satisfy the PCAC relation between them. The talk examines the broader question--which and how many of the theoretically allowed positive parity states $N(\text{p})\pi (-\text{p})$, $N(\text{0})\pi (\text{0})\pi (\text{0})$, $N(\text{p})\pi (\text{0})$, $N(\text{0})\pi (\text{p}),\dots$ make significant contributions to a given nucleon matrix element? New data for the axial, electric and magnetic form factors are presented. They continue to show trends observed in Ref[1]. The N${}^2$LO $\chi$PT analysis of the ESC to the pion-nucleon sigma term, ${\sigma }_{\pi N}$, has been extended to include the $\Delta$ as an explicit degree of freedom [2]. The conclusion reached in Ref [3] that $N\pi$ and $N\pi \pi$ states each contribute about 10 MeV to ${\sigma }_{\pi N}$, and the consistency between the lattice result with $N\pi$ state included and the phenomenological estimate is not changed by this improvement.

    ↳ hep-lathep-phnucl-thPoS(2023)·5 citations
20. 20*

    Continuous Spectrum on Cosmological Collider

    Shuntaro Aoki🇰🇷

    We study the effects of a massive field with a continuous spectrum (continuum isocurvaton) on the inflationary bispectrum in the squeezed limit. As a concrete example, we extend the quasi-single field inflation model to include a continuum isocurvaton with a well-motivated spectral density from extra dimensions and focus on a contribution to the bispectrum with a single continuum isocurvaton exchange. In contrast to the usual case without the continuous spectrum, the amplitude of the bispectrum has a damping feature in the deep squeezed limit, which can be strong evidence for the continuous spectrum.

    ↳ hep-thastro-ph.COhep-phJCAP(2023)·38 citations
21. 21*

    ALP induced polarization effects on photons from blazars

    Giorgio Galanti🇮🇹 · Marco Roncadelli🇮🇹 · Fabrizio Tavecchio🇮🇹

    Axion-like particles (ALPs), which are very light neutral spin zero elusive particles primarily interacting with two photons and predicted by superstring and superbrane theories, have come to help by solving two distinct problems about blazars (a type of active galactic nuclei), thus providing two hints at the existence of ALPs themselves. In the presence of an external magnetic field, ALPs produce: (i) photon-ALP oscillations, (ii) the change of the polarization state of photons. The former effect has many consequences in the astrophysical contest, such as the modification of the transparency of the Universe and the alteration of the astrophysical spectra. We address here the latter effect by analyzing how the photon degree of linear polarization and the polarization angle get modified by photon-ALP interaction in the case where photons are generated at the jet base of some BL Lacs (a blazar class): OJ 287, BL Lacertae, Markarian 501 and 1ES 0229+200, by considering both a leptonic and hadronic emission mechanism. We show that OJ 287 and BL Lacertae are good observational targets for ALP studies both in the X-ray band with IXPE (already operative) and with the proposed eXTP, XL-Calibur, NGXP and XPP missions and in the high-energy range with the COSI, e-ASTROGAM and AMEGO missions, while 1ES 0229+200 represents a strong candidate in the X-ray band only. Since these blazars show a very high final photon degree of linear polarization, which cannot be explained by conventional physics, such a possible detection would represent an additional hint at the ALP existence. Instead, Markarian 501 does not appear as a good target for these studies. We conclude that all these observatories can give us additional fundamental information about ALP physics.

    ↳ astro-ph.HEhep-phPRD(2023)·15 citations
22. 22*

    Radiative Transitions in Charmonium from Lattice QCD

    James Delaney🇬🇧 · Christopher E. Thomas🇬🇧 · Sinéad M. Ryan🇮🇪

    The coupling of various charmonium mesons to a photon is studied using lattice QCD, giving access to radiative form factors and transitions, and probing the mesons' structure. Methods are developed which allow the robust determination of amplitudes, including those involving an excited state as well as multiple form factors, for a range of kinematics. These are applied in dynamical lattice QCD calculations using the distillation technique to compute the underlying three-point correlation functions. Form factors and amplitudes involving the low-lying charmonia, ${\eta }_c$, $J/\psi$, ${\chi }_{c0}$ and ${\eta }_c^{\prime }$, are calculated, demonstrating the methods and providing the first dynamical lattice QCD results for some quantities.

    ↳ hep-lathep-phJHEP(2024)·20 citations
23. 23*

    NSC++: Non-Standard Cosmologies in C++

    Dimitrios Karamitros🇬🇧

    We introduce NSC++, a header-only C++ library that simulates the evolution of the plasma and a decaying fluid in the early Universe. NSC++ can be used in C++ programs or called directly from python scripts without significant overhead. There is no special installation process or external dependencies. Furthermore, there are example programs that can be modified to handle several cases.

    ↳ astro-ph.COhep-phComput.Phys.Commun.(2023)·2 citations
24. 24*

    $S_8$ Tension in the Context of Dark Matter-Baryon Scattering

    Adam He🇺🇸 · Mikhail M. Ivanov🇺🇸 · Rui An🇺🇸 · Vera Gluscevic🇺🇸

    We explore an interacting dark matter (IDM) model that allows for a fraction of dark matter (DM) to undergo velocity-independent scattering with baryons. In this scenario, structure on small scales is suppressed relative to the cold DM scenario. Using the effective field theory of large-scale structure, we perform the first systematic analysis of BOSS full-shape galaxy clustering data for the IDM scenario, and we find that this model alleviates the $S_8$ tension between large-scale structure and Planck data. Adding the $S_8$ prior from DES to our analysis further leads to a mild $\sim 3\sigma$ preference for a non-vanishing DM-baryon scattering cross-section, assuming $\sim 10\%$ of DM is interacting and has a particle mass of 1 MeV. This result produces a modest $\sim 20$% suppression of the linear power at $k\lesssim 1h$/Mpc, consistent with other small-scale structure observations. Similar scale-dependent power suppression was previously shown to have the potential to resolve $S_8$ tension between cosmological data sets. The validity of the specific IDM model explored here will be critically tested with upcoming galaxy surveys at the interaction level needed to alleviate the $S_8$ tension.

    ↳ astro-ph.COhep-phApJL(2023)·47 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.