Tue·Aug 31, 2021Tuesday·August 31, 2021

1. 01*

   Mass Spectra of One or Two Heavy Quark Mesons and Diquarks within a Nonrelativistic Potential Model

   L.X. Gutiérrez-Guerrero🇲🇽 · A. Alfaro🇲🇽 · A. Raya🇲🇽

   In this article, the mass spectra of mesons with one or two heavy quarks and their diquarks partners are estimated within a non-relativistic framework by solving Schrödinger equation with an effective potential inspired by a symmetry preserving Poincaré covariant vector-vector contact interaction model of quantum chromodynamics. Matrix Numerov method is implemented for this purpose. In our survey of mesons with heavy quarks, we fix the model parameter to the masses of ground-states and then extend our calculations for radial excitations and diquarks. The potential model used in this work gives results which are in good agreement with experimental data and other theoretical calculations.

   hep-phnucl-exnucl-thInt.J.Mod.Phys.A(2021)·12 citations
2. 02*

   Analysis of the doubly-charmed tetraquark molecular states with the QCD sum rules

   Qi Xin🇨🇳 · Zhi-Gang Wang🇨🇳

   In the present work, we investigate the scalar, axialvector and tensor doubly-charmed tetraquark molecular states without strange, with strange and with doubly-strange via the QCD sum rules, and try to make assignment of the $T_{cc}^{+}$ from the LHCb collaboration in the scenario of molecular states. The predictions favor assigning the $T_{cc}^{+}$ to be the lighter $D{D}^{\ast }$ molecular state with the spin-parity $J^P=1^{+}$ and isospin $I=0$, while the heavier $D{D}^{\ast }$ molecular state with the spin-parity $J^P=1^{+}$ and isospin $I=1$ still escapes experimental detections, the observation of the heavier $D{D}^{\ast }$ molecular state would shed light on the nature of the $T_{cc}^{+}$. All the predicted doubly-charmed tetraquark molecular states can be confronted to the experimental data in the future.

   hep-phEPJA(2022)·112 citations
3. 03*

   The $\mu \to e\gamma$ decay in an EW-scale non-sterile RH neutrino model

   D. N. Dinh🇻🇳

   We study in this research the phenomenology of $\mu \to e\gamma$ decay in a scenario of the class of extended models with non-sterile right-handed (RH) neutrino at electroweak (EW) scale proposed by P.Q. Hung. Field content of the standard model (SM) is enlarged by introducing for each SM fermion a corresponding mirror partner with the same quantum numbers beside opposite chirality. Light neutrino masses are generated via the type-I see-saw mechanism and it is also proved to be relevant with low energy within the EW scale of the RH neutrino masses. We introduce the model and derive branching ratio of the $\mu \to e\gamma$ decay at one-loop approximation with the participation of W gauge boson, neutral and singly charged Higgs scalars. After that we set constraints on relevant parameters and predict the sensitivities of the decay channel under the present and future experiments.

   hep-phEPJC(2022)·3 citations
4. 04*

   Heavy quarkonia in a baryon asymmetric strongly magnetized hot quark matter

   Salman Ahamad Khan🇮🇳 · Mujeeb Hasan🇮🇳 · Binoy Krishna Patra🇮🇳

   Recently there is a resurrection in the study of heavy quark bound states in a hot and baryonless matter with an ambient magnetic field but the matter produced at heavy-ion collider experiments is not perfectly baryonless, so we wish to explore the effect of small baryon asymmetry on the properties of heavy quarkonia immersed in a strongly magnetized hot quark matter. Therefore, we have first revisited the structure of gluon self-energy tensor in the above environment to compute the resummed propagator for gluons. This resummed propagator embodies the properties of medium, which gets translated into the (complex) potential between $Q$ and $\bar{Q}$ placed in the medium. We observe that the baryon asymmetry makes the real-part of potential slightly more attractive and weakens the imaginary-part. This opposing effects thus lead to the enhancement of binding energies and the reduction of thermal widths of $Q\bar{Q}$ ground states, respectively. Finally, the properties of quarkonia thus deciphered facilitates to compute the dissociation points of $J/\psi$ and ${\rm Y}$, which are found to have slightly larger values in the presence of baryon asymmetry. For example, $J/\psi$ is dissociated at $1.64T_c$, $1.69T_c$, and $1.75T_c$, whereas ${\rm Y}$ is dissociated at $1.95T_c$, $1.97T_c$ and $2.00T_c$, for $\mu =0,60$ and $100$ MeV, respectively. This observation prevents early dissociation of quarkonia in the matter produced at ultrarelativistic heavy ion collisions with a small net baryon number, compared to the ideal baryonless matter.

   hep-phNPA(2023)·9 citations
5. 05*

   A relativistic model for the Charmonium spectrum with a reduced number of free parameters

   M. De Sanctis🇨🇴

   A previously introduced reduction of the Dirac equation is used to study the Charmonium spectrum. A regularized vector potential that only depends on the coupling constant and on the regularization radius is adopted, considering the interacting quark as an extended source of the Chromo-electric field. A scalar interaction is also introduced with some constraints for its parameters. A good description of the structure of the Charmonium spectrum is obtained with only three free parameters.

   hep-phActa Phys.Polon.B(2021)·6 citations
6. 06*

   Doubly charmed molecular pentaquarks

   Rui Chen🇨🇳 · Ning Li🇨🇳 · Zhi-Feng Sun🇨🇳 · Xiang Liu🇨🇳 · Shi-Lin Zhu🇨🇳

   We perform a systematic exploration of the possible doubly charmed molecular pentaquarks composed of ${\Sigma }_c^{(\ast )}{D}^{(\ast )}$ with the one-boson-exchange potential model. After taking into account the $S-D$ wave mixing and the coupled channel effects, we predict several possible doubly charmed molecular pentaquarks, which include the ${\Sigma }_{c}D$ with $I(J^P)=1/2(1/2^{-})$, ${\Sigma }_c^{\ast }D$ with $1/2(3/2^{-})$, and ${\Sigma }_c{D}^{\ast }$ with $1/2(1/2^{-})$, $1/2(3/2^{-})$. The ${\Sigma }_{c}D$ state with $3/2(1/2^{-})$ and ${\Sigma }_c{D}^{\ast }$ state with $3/2(1/2^{-})$ may also be suggested as candidates of doubly charmed molecular pentaquarks. The ${\Sigma }_{c}D$ and ${\Sigma }_c^{\ast }D$ states can be searched for by analyzing the ${\Lambda }_{c}D\pi$ invariant mass spectrum of the bottom baryon and $B$ meson decays. The ${\Sigma }_c{D}^{\ast }$ states can be searched for in the invariant mass spectrum of ${\Lambda }_c{D}^{\ast }\pi$, ${\Lambda }_{c}D\pi \pi$ and ${\Lambda }_{c}D\pi \gamma$. Since the width of ${\Sigma }_c^{\ast }$ is much larger than that of $D^{\ast }$, ${\Sigma }_c^{\ast }D\to {\Lambda }_{c}D\pi$ will be the dominant decay mode. We sincerely hope these candidates for the doubly charmed molecular pentaqurks will be searched by LHCb or BelleII collaboration in the near future.

   hep-phhep-exPLB(2021)·40 citations
7. 07*

   Splitting of elliptic flow in non-central relativistic heavy-ion collisions

   Zhengyu Chen🇨🇳 · Zeyan Wang🇨🇳 · Carsten Greiner🇩🇪 · Zhe Xu🇨🇳

   We predict a new effect due to the presence of the global vorticity in non-central relativistic heavy-ion collisions, namely a splitting of the elliptic flow parameter $v_2$ at non-zero rapidity. The size of the splitting is proposed as a new observable that can be used to constrain the initial vortical configuration of the produced QCD matter in experiments. The new findings are demonstrated by numerical calculations employing the parton cascade model, Boltzmann Approach of MultiParton Scatterings (BAMPS), for non-central Au + Au collisions at $\sqrt{s_{NN}}=200GeV$.

   hep-phhep-exnucl-exnucl-th7 citations
8. 08*

   Inverse magneto-rotational catalysis and the phase diagram of a rotating hot and magnetized quark matter

   N. Sadooghi🇮🇷 · S. M. A. Tabatabaee🇮🇷 · F. Taghinavaz🇮🇷

   We study the properties of a hot and magnetized quark matter in a rotating cylinder in the presence of a constant magnetic field. To do this, we solve the corresponding Dirac equation using the Ritus eigenfunction method. This leads to the energy dispersion relation, Ritus eigenfunctions, and the quantization relation for magnetized fermions. To avoid causality-violating effects, we impose a certain global boundary condition, and study its effect, in particular, on the energy eigenmodes and the quantization relations of fermions. Using the fermion propagator arising from this method, we then solve the gap equation at zero and nonzero temperatures. At zero temperature, the dynamical mass $\bar{m}$ does not depend on the angular frequency, as expected. We thus study its dependence on the distance $r$ relative to the axis of rotation and the magnetic field $B$, and explore the corresponding finite size effect for various couplings $G$. We then consider the finite temperature case. The dependence of $\bar{m}$ on the temperature $T$, magnetic field $B$, angular frequency $\Omega$, and distance $r$ for various $G$ is studied. We show that $\bar{m}$ decreases, in general, with $B$ and $\Omega$. This is the ''inverse magneto-rotational catalysis (IMRC)'' or the ''rotational magnetic inhibition'', previously discussed in the literature. To explore the evidence of this effect in the phase diagrams of our model, we examine the phase portraits of the critical temperature $T_c$ as well as the critical angular frequency ${\Omega }_c$ with respect to $G,B,\Omega$, and $r$ as well as $G,B,T$, and $r$, respectively. We show that $T_c$ and ${\Omega }_c$ decrease, in particular, with $B$. This is interpreted as clear evidence for IMRC.

   hep-phhep-latnucl-thPRD(2021)·47 citations
9. 09*

   An analysis of polarized parton distribution functions with nonlinear QCD evolution equations

   Chengdong Han🇨🇳 · Gang Xie🇨🇳 · Rong Wang🇨🇳 · Xurong Chen🇨🇳

   We present the polarized parton distribution functions from a QCD analysis of the worldwide polarized deep inelastic scattering data, based on the dynamical parton distribution model. All the sea quarks and gluons are dynamically generated from QCD radiations, with the nonperturbative input contains only the polarized valence quark distributions. This approach leads to a simple parametrization, which has only four free parameters. In the analysis, we apply the DGLAP equations with parton-parton recombination corrections. The parameterized nonperturbative input at an extremely low $Q_0^2$ reproduces well the spin-dependent structure functions measured at high $Q^2$. Comparisons with experimental observations and some other polarized parton distribution functions are also shown. Our results are in good agreement with the experimental data and consistent with some other parameterized models. Furthermore, our analysis gives the positive polarized gluon distribution and it suggests that the gluon distribution plays an important role to the proton spin content. The polarized antiquark distributions are non-zero at high $Q^2$ but quite small compared to polarized valence quark distribution, based on this dynamical parton model analysis. This analysis shows smaller statistical uncertainties for the polarized sea quark and gluon distributions, thanks to the fewer free parameters used for the parametrization of the initial polarized PDFs.

   hep-phNPB(2022)·5 citations
10. 10*

    Impact of SM parameters and of the vacua of the Higgs potential in gravitational waves detection

    Felipe F. Freitas🇵🇹 · Gabriel Lourenço🇵🇹 · António P. Morais🇵🇹 · André Nunes🇵🇹 · João Olívia🇵🇹 · Roman Pasechnik🇸🇪 · Rui Santos🇵🇹 · João Viana🇵🇹

    In this work we discuss two different phases of a complex singlet extension of the Standard Model (SM) together with an extension that also includes new fermion fields, in particular, a Majoron model equipped with an inverse seesaw mechanism. All considered scenarios contain a global $\mathrm{U}(1)$ symmetry and allow for first-order phase transitions while only two of them are strong enough to favour the detection of primordial gravitational waves (GWs) in planned experiments such as LISA. In particular, this is shown to be possible in the singlet extension with a non vanishing real VEV at zero temperature and also in the model with extra fermions. In the singlet extension with no additional fermions, the detection of GWs strongly depends on the $\mathrm{U}(1)$ symmetry breaking pattern of the scalar potential at zero temperature. We study for the first time the impact of the precision in the determination of the SM parameters on the strength of the GWs spectrum. It turns out that the variation of the SM parameters such as the Higgs boson mass and top quark Yukawa coupling in their allowed experimental ranges has a notable impact on GWs detectability prospects.

    hep-phastro-ph.COJCAP(2022)·16 citations
11. 11*

    The Fragmented Glueball: A Personal View

    Eberhard Klempt🇩🇪

    A coupled-channel analysis has been performed to identify the spectrum of scalar mesons. The data include BESIII data on radiative $J/\psi$ decays into ${\pi }^0{\pi }^0$,$K_S{K}_S$, $\eta \eta$, and $\omega \varphi$, 15 Dalitz plots from $\bar{p}N$ annihilation at rest at LEAR, the CERN-Munich multipoles for $\pi \pi$ elastic scattering, the $S$-wave from BNL data on $\pi \pi$ scattering into $K_S{K}_S$, from GAMS data on $\pi \pi \to {\pi }^0{\pi }^0,\eta \eta$, and $\eta {\eta }^{\prime }$, and NA48/2 data on low-mass $\pi \pi$ interactions from $K^{\pm }\to \pi \pi e^{\pm }\nu$ decays. The analysis reveals the existence of ten scalar isoscalar resonances. The resonances can be grouped into two classes: resonances with a large SU(3) singlet component and those with a large octet component. The production of isoscalar resonances with a large octet component should be suppressed in radiative $J/\psi$ decays. However, in a limited mass range centered at 1900\,MeV, these mesons are produced abundantly. Mainly-singlet scalar resonances are produced over the full mass range but with larger intensity at 1900\,MeV. The total scalar isoscalar yield in radiative decays into scalar mesons shows a clear peak which is interpreted as the scalar glueball of lowest mass.

    hep-phEPJ Web Conf.(2022)·2 citations
12. 12*

    Particle production at a finite potential step: Transition from Euler-Heisenberg to Klein paradox

    Stefan Evans🇺🇸 · Johann Rafelski🇺🇸

    Spontaneous pair production for spin-$1/2$ and spin-$0$ particles is explored in a quantitative manner for a static $\tanh$-Sauter potential step (SS), evaluating the imaginary part of the effective action. We provide finite-valued per unit-surface results, including the exact sharp-edge Klein paradox (KP) limit, which is the upper bound to pair production. At the vacuum instability threshold the spin-$0$ particle production can surpass that for the spin-$1/2$ rate. Presenting the effect of two opposite sign Sauter potential steps creating a well we show that spin-$0$ pair production, contrary to the case of spin-$1/2$, requires a smoothly sloped wall.

    hep-phEPJA(2021)·5 citations
13. 13*

    WIMP Dark Matter Hidden behind its Companion

    Jun Guo🇨🇳 · Zhaofeng Kang🇨🇳 · Peng Zhang🇨🇳

    The WIMP dark matter (DM) hypothesis now is in an awkward position, owing to the stronger and stronger exclusion from DM direct detection. In this article we design a mechanism to evade this constraint.The idea is simple. DM has a companion, and they are both charged under the DM protecting symmetry G; they admit the trilinear coupling DM-DM-companion, so the latter provides a portal to the standard model (SM) via, for instance, the coupling to Higgs doublet.Then, DM semi-annihilates into the companion to arrive correct relic density, without leaving DM-nucleon scattering signal. The idea can be realized for ZN symmetric models with N >2.We stress that this mechanism has the characteristics of co-annihilation, and as a matter of fact its effect becomes necessary near or above the TeV region. This means that it may be difficult to detect our dark matter directly or indirectly.

    hep-phPLB(2022)·7 citations
14. 14*

    $D_{s0}(2590)$ as a dominant $c\bar{s}$ state with a small $D^{\ast }K$ component

    Jia-Ming Xie🇨🇳 · Ming-Zhu Liu🇨🇳 · Li-Sheng Geng🇨🇳

    The recently discovered $D_{s0}(2590)$ state by the LHCb collaboration was regarded as the first excited state of ${}^1{S}_0$ charmed-strange meson. Its mass is, however, lower than the Godfrey-Isgur quark model prediction by about 80 MeV. In this work, we take into account the $D^{\ast }K$ contribution to the bare $c\bar{s}$ state, and show that the coupled-channel interaction induces an 88 MeV shift with respect to the conventional quark model $c\bar{s}$ state, which is much closer to the experimental mass. Our study shows that in addition to $S$-wave, $P$-wave coupled-channel interactions also play a role for hadrons located close to two-hadron thresholds. We further scrutinize the unquenched quark model results with a model independent approach. It is shown that the two-body $D^{\ast }K$ decay width is proportional to the weight of the $D^{\ast }K$ component. To saturate the experimental total decay width with the $D^{\ast }K$ partial decay width we need a weight of about 60\% while to reproduce the unquenched quark model result a weight of about 5\% is needed. Therefore, we encourage future experimental studies on the two-body $D^{\ast }K$ partial decay of $D_{s0}(2590)$.

    hep-phhep-exPRD(2021)·23 citations
15. 15*

    Probing Neutrino Dipole Portal at COHERENT Experiment

    Jihn E. Kim🇰🇷 · Arnab Dasgupta🇰🇷 · Sin Kyu Kang🇰🇷

    Motivated by the first observation of coherent-elastic neutrino-nucleus scattering at the COHERENT experiment, we confront the neutrino dipole portal giving rise to the transition of the standard model neutrinos to sterile neutrinos with the recently released CENNS 10 data from the liquid argon as well as the CsI data of the COHERENT experiment. Performing statistical analysis of those data, we show how the transition magnetic moment can be constrained for the range of the sterile neutrino mass between 10 keV and 40 MeV.

    hep-phJHEP(2021)·30 citations
16. 16*

    Phase structures of neutral dense quark matter and application to strange stars

    Shu-Sheng Xu🇨🇳

    In the contact interaction model, the quark propagator has only one solution, chiral symmetry breaking solution, at vanish temperature and density. Inspire by Y. Jiang and Z.-F. Cui, we introduce 2+1 flavors quark condensates feedback on coupling strength, the Wigner solution appears in some region of parameters. It enables us to tackle chiral phase transition as two-phase coexistences. At finite chemical potential, we analyze the chiral phase transition to the conditions of electric charge neutrality and $\beta$ equilibrium. The four chemical potentials, ${\mu }_u$, ${\mu }_d$, ${\mu }_s$ and ${\mu }_e$, are constrained by three conditions, there is one independent variable that remained, we choose the average quark chemical potential as the free variable. All quark masses and number densities suffer discontinuities at the phase transition point. The strange quarks appear after the phase transition due to the system needs more energy to produce a d-quark than an s-quark. Take the EOS as an input, the TOV equations are solved numerically, we show that the mass-radius relation is sensitive to the EOSs. The maximum mass of strange quark stars is not susceptible to our introduced parameter ${\Lambda }_q$.

    hep-phCPC(2022)·2 citations
17. 17*

    Production of the $T_{cc}^{+}$ state in the $\gamma p\to D^{+}{\bar{T}}_{cc}^{-}{\Lambda }_c^{+}$ reaction

    Yin Huang🇨🇳 · Hong Qiang Zhu🇨🇳 · Li-Sheng Geng🇨🇳 · Rong Wang🇨🇳

    Stimulated by the recent LHCb observation of a new exotic charged structure $T_{cc}^{+}$, we propose to use the central diffractive mechanism existing in the $\gamma p\to D^{+}{\bar{T}}_{cc}^{-}{\Lambda }_c^{+}$ (${\bar{T}}_{cc}$ is antiparticle of $T_{cc}^{+}$) reaction to produce $T_{cc}^{+}$. Our theoretical approach is based on the chiral unitary theory where the $T_{cc}^{+}$ resonance is dynamically generated. With the coupling constant of the $T_{cc}^{+}$ to $D{D}^{\ast }$ channel obtained from chiral unitary theory, the total cross sections of the $\gamma p\to D^{+}{\bar{T}}_{cc}^{-}{\Lambda }_c^{+}$ reaction are evaluated. Our study indicates that the cross section for $\gamma p\to D^{+}{\bar{T}}_{cc}^{-}{\Lambda }_c^{+}$ reaction are of the order of 1.0 pb, which is accessible at the proposed EicC~\cite{Anderle:2021wcy} and US-EIC~\cite{Accardi:2012qut} due to the higher luminosity. If measured in future experiments, the predicted total cross sections can be used to test the (molecular) nature of the $T_{cc}^{+}$.

    hep-phPRD(2021)·39 citations
18. 18*

    Angular instabilities of a homogeneous neutrino gas from (pseudo)scalar nonstandard self-interactions

    Oleg G. Kharlanov🇷🇺

    We demonstrate that in the presence of (pseudo)scalar four-fermion nonstandard interactions, a homogeneous and isotropic gas of Majorana neutrinos placed in a strong magnetic field can exhibit an angular flavor instability mixing the two neutrino helicities (i.e., a `neutrino-antineutrino' instability). This instability is most pronounced for the inverted mass hierarchy and high neutrino number densities; at the same time, even a tiny transition magnetic moment of the order of $10^{-24}{\mu }_{\text{B}}$ is quite sufficient to trigger it. We study the properties of the neutrino-antineutrino mode using the linear stability analysis and then perform a numerical simulation to analyze the late-time properties of an oscillating neutrino gas with V-A and (pseudo)scalar interactions. The latter analysis reveals three phases of a chaotic, `thermalized' late-time state of neutrinos: along with a low-density phase with the SO(3) symmetry broken by V-A interactions and a symmetric high-density phase, another, (pseudo)scalar-induced phase with a broken rotational symmetry appears. The phases can be distinguished by the average late-time probabilities of (anti)neutrino flavors and/or by the neutrino-to-antineutrino ratio, the latter being a key quantity for the (pseudo)scalar phase. We thus show that observations of these quantities from a supernova could place new constraints on the (pseudo)scalar nonstandard neutrino interactions.

    hep-phhep-th0 citations
19. 19*

    Positron energy distribution in factorized trident process

    A.I. Titov🇷🇺 · U. Hernandez Acosta🇩🇪 · B. Kampfer🇩🇪

    We estimate the energy distribution of positrons produced in the interaction of ultra-relativistic electrons with a high-intensity laser beam. The underlying trident process is factorized on the probabilistic level. That is, we deploy a two-step mechanism for the formation of electron-positron pairs. In the first step, a high-energy photon is produced as a result of nonlinear Compton scattering. In the second step, an electron-positron pair is created by the nonlinear (multi-photon) Breit-Wheeler process.

    hep-phPRA(2021)·10 citations
20. 20*

    Di-Gluonium Sum Rules, I = 0 Scalar Mesons and Conformal Anomaly

    Stephan Narison · LUPM (CNRS Montpellier-FR) · iHEPMAD (Univ. Antananarivo-MG)

    We revisit, scrutinize, improve, confirm and complete our previous results [1-3] from the scalar di-gluonium sum rules within the standard SVZ-expansion at N2LO without instantons and beyond the minimal duality ansatz : "one resonance + QCD continuum" parametrization of the spectral function which is necessary for a better understanding of the complex spectra of the $I=0$ scalar mesons. We select different (un)subtracted sum rules (USR) moments of degree $\le$ 4 for extracting the two lowest gluonia masses and couplings. We obtain: $[M_{{\sigma }_B},f_{{\sigma }_B}]=[1.07(13),0.46(16)],[M_{G_1},f_{G_1}][1.55(12),0.37(11)]$ GeV and the corresponding masses of the radial excitations : $M_{{\sigma }_B^{\prime }}$= 1.11(12) and $M_{G_1^{\prime }}=1.56(14)$ GeV which are (unexpectedly) almost degenerated with the ground states. The 2nd radial excitation is found to have a much heavier mass: $M_{G_2}\simeq$ 2.99(22) GeV. Combining these results with some Low-Energy Vertex Sum Rules (LEV-SR), we predict some hadronic widths and classify them into two groups : -- The $\sigma$-like (${\sigma }_B,{\sigma }_B^{\prime }$) which decay copiously to $\pi \pi$ from OZI-violating process and the ${\sigma }_B^{\prime }$ to $2(\pi \pi )S$ through $\sigma \sigma$. -- The $G$-like $(G_1,G_1^{\prime }$ and eventually $G_2$) which decay into ${\eta }^{\prime }\eta ,\eta \eta$ through the $U(1{)}_A$ gluonic vertex. Besides some eventual mixings with quarkonia states, we may expect that the observed $\sigma /f_0(500)$ and $f_0(137)$ are $\sigma$-like while the $f_0(1.5)$ and $f_0(1.7)$ are $G$-like gluonia. The high mass $G_2(2.99)$ can also mix with the $G_1,G_1^{\prime }$ to bring the gluon component of the gluonia candidates above 2 GeV. We also estimate the conformal charge ${\psi }_G(0)=2.09(29)$ GeV${}^4$ and its slope $10^2{\psi }_G^{\prime }(0)=-22(29)$ GeV${}^2$. Our results are summarized in Table 1.

    hep-phhep-exhep-latNPA(2022)·17 citations
21. 21*

    Probing the tau electric dipole moment at BEPC-II collider energies

    Werner Bernreuther🇩🇪 · Long Chen🇩🇪 · Otto Nachtmann🇩🇪

    We investigate the prospects of the search for a nonzero $\tau$ EDM form factor $d_{\tau }(s)$ in $\tau$ pair production by $e^{+}{e}^{-}$ collisions at BEPC-II collider energies. We compute the expectation values and covariances of simple and optimal $CP$-odd observables for $\tau$-pair production at $\sqrt{s}=4.18$ GeV and $4.95$ GeV with subsequent decays of ${\tau }^{\pm }$ into major leptonic or semihadronic modes. For the $\tau$ decays to two pions and three charged pions we take the full kinematic information of the hadronic system into account. Applying cuts and using realistic assumptions on the eventually attainable integrated luminosities at these energies, $\mathcal{L}(4.18)=3\times 10^4{\mathrm{pb}}^{-1}$ and $\mathcal{L}(4.95)=10^4{\mathrm{pb}}^{-1}$, respectively, we find the following. By taking into account purely semihadronic and semihadronic-leptonic ${\tau }^{+}{\tau }^{-}$ decays one can achieve with optimal $CP$-odd observables the 1 s.d. sensitivities $\delta \mathrm{Re}{d}_{\tau }=4.5\times 10^{-18}$ ecm ($5.3\times 10^{-18}$ ecm) and $\delta \mathrm{Im}{d}_{\tau }=2.2\times 10^{-18}$ ecm ($2.7\times 10^{-18}$ ecm) at $\sqrt{s}=4.18$ GeV ($4.95$ GeV).

    hep-phhep-exPRD(2021)·8 citations
22. 22*

    Early Matter Domination from Long-Lived Particles in the Visible Sector

    Rouzbeh Allahverdi🇺🇸 · Jacek K. Osiński🇵🇱

    We show that a nonstandard cosmological history with a period of early matter domination driven by a sub-TeV visible-sector particle can arise rather naturally. This scenario involves a long-lived standard model singlet that acquires a thermal abundance at high temperatures from decays and inverse decays of a parent particle with SM charge(s), and subsequently dominates the energy density of the Universe as a frozen species. Entropy generation at the end of early matter domination dilutes the abundance of dangerous relics (such as gravitinos) by a factor as large as $10^4$. The scenario can accommodate the correct dark matter relic abundance for cases with $⟨{\sigma }_{\mathrm{ann}}v{⟩}_{\mathrm{f}}\lessgtr 3\times 10^{-26}$cm${}^3$s${}^{-1}$. More importantly, the allowed parameter space can be directly probed by proposed searches for neutral long-lived particles at the energy frontier, allowing us to use particle physics experiments to reconstruct the cosmological history just prior to big bang nucleosynthesis.

    hep-phastro-ph.COhep-thPRD(2022)·24 citations
23. 23*

    Solving the puzzle of high temperature light (anti)-nuclei production in ultra-relativistic heavy ion collisions

    Tim Neidig🇩🇪 · Kai Gallmeister🇩🇪 · Carsten Greiner🇩🇪 · Marcus Bleicher🇩🇪 · Volodymyr Vovchenko🇺🇸

    The creation of loosely bound objects in heavy ion collisions, e.g. light clusters, near the phase transition temperature $\left(T_{\mathrm{ch}}\approx 155\mathrm{MeV}\right)$ has been a puzzling observation that seems to be at odds with Big Bang nucleosynthesis suggesting that deuterons and other clusters are formed only below a temperature $T\approx 0.1-1\text{MeV}$. We solve this puzzle by showing that the light cluster abundancies in heavy ion reactions stay approximately constant from chemical freeze-out to kinetic freeze-out. To this aim we develop an extensive network of coupled reaction rate equations including stable hadrons and hadronic resonances to describe the temporal evolution of the abundancies of light (anti-)(hyper-)nuclei in the late hadronic environment of an ultrarelativistic heavy ion collision. It is demonstrated that the chemical equilibration of the light nuclei occurs on a very short timescale as a consequence of the strong production and dissociation processes. However, because of the partial chemical equilibrium of the stable hadrons, including the nucleon feeding from $\Delta$ resonances, the abundancies of the light nuclei stay nearly constant during the evolution and cooling of the hadronic phase. This solves the longstanding contradiction between the thermal fits and the late stage coalescence (and the Big Bang nucleosynthesis) and explains why the observed light cluster yields are compatible with both a high chemical production temperature and a late state emission as modelled by coalescence. We also note in passing that the abundancies of the light clusters in the present approach are in excellent agreement with those measured by ALICE at LHC.

    hep-phPLB(2022)·34 citations
24. 24*

    Neutrinos and strong interactions: QCD (and beyond?)

    C.A. García Canal🇦🇷

    In this talk the answer to the question: what neutrinos have to do with QCD, the present theory of strong interactions? is presented. The answer is positive as some strong arguments on this assertion that are presented bring out.

    hep-ph0 citations
25. 25*

    Multiple soft radiation at one-loop order and the emission of a soft quark-antiquark pair

    Stefano Catani🇮🇹 · Leandro Cieri🇪🇸

    We consider the radiation of two or more soft partons in QCD hard-scattering at one-loop order. The corresponding scattering amplitude is singular, and the singular behaviour is controlled by a process-independent soft current. Using regularization in $d=4-2ϵ$ space-time dimensions, we explicitly evaluate the ultraviolet and infrared divergent ($ϵ$-pole) terms of the one-loop soft current for emission of an arbitrary number of soft partons in a generic hard-scattering process. Then we consider the specific case of soft quark-antiquark ($q\bar{q}$) emission and we compute the one-loop current by including the finite terms. We find that the one-loop soft-$q\bar{q}$ current exhibits a new type of transverse-momentum singularity, which has a quantum (absorptive) origin and a purely non-abelian character. At the squared amplitude (cross section) level, this transverse-momentum singularity produces contributions to multijet production processes in hadron collisions. The one-loop squared current also leads to charge asymmetry terms, which are a distinctive features of soft-$q\bar{q}$ radiation. We also extend these results to the cases of QED and mixed QCD$\times$QED radiative corrections for soft fermion-antifermion emission.

    hep-phEPJC(2022)·29 citations
26. 26*

    A new approach to semi-inclusive deep-inelastic scattering with QED and QCD factorization

    Tianbo Liu🇨🇳 · W. Melnitchouk🇺🇸 · Jian-Wei Qiu🇺🇸 · N. Sato🇺🇸

    We present the details of a new factorized approach to semi-inclusive deep-inelastic scattering which treats QED and QCD radiation on equal footing, and provides a systematically improvable approximation to the extraction of transverse momentum dependent parton distributions. We demonstrate how the QED contributions can be well approximated by collinear factorization, and illustrate the application of the factorized approach to QED radiation in inclusive scattering. For semi-inclusive processes, we show how radiation effects prevent a well-defined "photon-nucleon" frame, forcing one to use a two-step process to account for the radiation. We illustrate the utility of the new method by explicit application to the spin-dependent Sivers and Collins asymmetries.

    hep-phhep-exnucl-exnucl-thJHEP(2021)·30 citations
27. 27*

    Using Secondary Tau Neutrinos to Probe Heavy Dark Matter Decays in Earth

    Matthew Saveliev🇺🇸 · Jeffrey Hyde🇺🇸

    Dark matter particles can be gravitationally trapped by celestial bodies, motivating searches for localized annihilation or decay. If neutrinos are among the decay products, then IceCube and other neutrino observatories could detect them. We investigate this scenario for dark matter particles above $m_{\chi }\gtrsim$ PeV producing tau neutrino signals, using updated modeling of dark matter capture and thermalization. At these energies, tau neutrino regeneration is an important effect during propagation through Earth, allowing detection at distances far longer than one interaction length. We show how large energy loss of tau leptons above $\sim$ PeV drives a wide range of initial energies to the same final energy spectrum of "secondary" tau neutrinos at the detector, and we provide an analytic approximation to the numerical results. This effect enables an experiment to constrain decays that occur at very high energies, and we examine the reach of the IceCube high-energy starting event (HESE) sample in the parameter space of trapped dark matter annihilations and decays above PeV. We find that the parameter space probed by IceCube searches would require dark matter cross sections in tension with existing direct-detection bounds.

    hep-phastro-ph.COastro-ph.HEPRD(2022)·4 citations
28. 28*

    Cosmology and Signals of Light Pseudo-Dirac Dark Matter

    Mariana Carrillo González🇬🇧 · Natalia Toro🇺🇸

    In this paper, we analyze the cosmological evolution, allowed parameter space, and observational prospects for a dark sector consisting of thermally produced pseudo-Dirac fermions with a small mass splitting, coupled to the Standard Model through a dark photon. This scenario is particularly notable in the context of sub-GeV dark matter, where the mass-off-diagonal leading interaction limits applicability of both CMB energy injection constraints and standard direct detection searches. We present the first general study of the thermal history of pseudo-Dirac DM with splittings from 100 eV to MeV, focusing on the depletion of the heavier "excited" state abundance via scatterings and decays, and on the distinctive signals arising from its small surviving abundance. We analyze CMB energy injection bounds on both DM annihilation and decay, accelerator-based probes, and new line-like direct-detection signals from the excited DM down-scattering on either nuclei or electrons, as well as future search prospects in each channel. We also comment on the relevance of this signal to the few-keV Xenon1T electron excess and on possible diurnal modulation of this signal, and introduce a signal-strength parametrization to facilitate the comparison of future experimental results to theoretical expectations.

    hep-phastro-ph.COJHEP(2022)·62 citations
29. 29*

    Ratios of jet and hadron spectra at LHC energies: measuring high-$p_T$ suppression without a $pp$ reference

    Jasmine Brewer🇨🇭 · Alexander Huss🇨🇭 · Aleksas Mazeliauskas🇨🇭 · Wilke van der Schee🇨🇭

    We analyze the reliability of several techniques for computing jet and hadron spectra at different collision energies. This is relevant for discovering energy loss in the upcoming oxygen-oxygen (OO) run at the LHC, for which a reference pp run is currently not planned. For hadrons and jets we compute the ratio of spectra between different pp collision energies in perturbative QCD, which can be used to construct a reference spectrum. Alternatively, it can be interpolated from measured spectra at nearby energies. We estimate the precision of both strategies for the spectra ratio relevant to the oxygen run, and conclude that the central values agree to 4% accuracy for hadrons and 2% accuracy for jets. Finally we propose taking the ratio of OO and pp spectra at different collision energies, which cleanly separates the experimental measurement and theoretical computation.

    hep-phnucl-exnucl-thPRD(2022)·16 citations
30. 30*

    Ordering multiple soft gluon emissions using Glauber-SCET

    Jeffrey Robert Forshaw🇬🇧 · Jack Holguin🇬🇧 · Aditya Pathak🇬🇧

    In QCD, the amplitude for multiple soft gluon emissions has been shown to exhibit a form of coherence, wherein one-loop corrections are rendered IR finite by the transverse momentum of the real emissions. Using a sequence of soft-collinear effective theories (SCET) with Glauber operators, we present a compact and elegant derivation of this property. Our derivation highlights an important role played by the Lipatov vertex. The EFT approach provides increased physical intuition and, for the first time, a clear road map for how this result can be extended to higher loop orders.

    hep-phPRD(2021)·1 citation
31. 31*

    A new form of QCD coherence for multiple soft emissions using Glauber-SCET

    Aditya Pathak🇬🇧

    The amplitude for multiple soft gluon emissions, ordered in their relative softness, can be written as a product of infrared (IR) divergent loop-expanded soft gluon currents and the matrix elements. In a more recent work, Angeles-Martinez, Forshaw and Seymour \cite{Angeles-Martinez:2016dph} (AMFS) showed that the result for this amplitude can in fact be re-expressed in an ordered evolution approach, involving \textit{IR finite} one-loop insertions where the virtual loop momentum is constrained in a highly non-trivial way by the $k_T$ of the adjacent real emissions. The result thus exhibits a novel amplitude level QCD coherence where the IR divergences originating only from the very last, softest, gluon emission remain, and the rest cancel. The proof of the AMFS result at one-loop in QCD, however, involves many diagrams, and only after carefully grouping and summing over all the diagrams does the correct ordering variable emerge, making the higher order extension a challenging task. Moreover, the compact, Markovian nature of the final AMFS result is suggestive of a deeper underlying physics that is obscured in the derivation using traditional diagrammatic QCD. By considering a (recursive) sequence of effective field theories (EFTs) with Glauber-SCET operators, we present an elegant derivation of this result involving only a handful of diagrams. The SCET derivation offers clean physical insights, and makes a higher order extension of the AMFS result tractable. We also show that the grouping of QCD graphs necessary to derive the AMFS result in full theory is already implicit in the Feynman rules of Glauber-SCET operators such that the same result can alternatively be derived with significantly less effort in a single EFT with multiple ordered soft gluon emissions.

    hep-phJHEP(2022)·4 citations
32. 32*

    Signals of primordial black holes at gravitational wave interferometers

    Jonathan Kozaczuk🇺🇸 · Tongyan Lin🇺🇸 · Ethan Villarama🇺🇸

    Primordial black holes (PBHs) can form as a result of primordial scalar perturbations at small scales. This PBH formation scenario has associated gravitational wave (GW) signatures from second-order GWs induced by the primordial curvature perturbation, and from GWs produced during an early PBH dominated era. We investigate the ability of next generation GW experiments, including BBO, LISA, and CE, to probe this PBH formation scenario in a wide mass range. Measuring the stochastic GW background with GW observatories can constrain the allowed parameter space of PBHs for masses 1e9 - 1e27 g. We also discuss possible GW sources from an unconstrained region where light PBHs (< 1e9 g) temporarily dominate the energy density of the universe before evaporating. We show how PBH formation impacts the reach of GW observatories to the primordial power spectrum and provide constraints implied by existing PBH bounds.

    ↳ astro-ph.COgr-qchep-phPRD(2022)·44 citations
33. 33*

    Global 4-group symmetry and 't Hooft anomalies in topological axion electrodynamics

    Yoshimasa Hidaka🇯🇵 · Muneto Nitta🇯🇵 · Ryo Yokokura🇯🇵

    We study higher-form global symmetries and a higher-group structure of a low-energy limit of $(3+1)$-dimensional axion electrodynamics in a gapped phase described by a topological action. We argue that the higher-form symmetries should have a semi-strict 4-group (3-crossed module) structure by consistency conditions of couplings of the topological action to background gauge fields for the higher-form symmetries. We find possible 't Hooft anomalies for the 4-group global symmetry, and discuss physical consequences.

    ↳ hep-thcond-mat.str-elhep-phPTEP(2022)·58 citations
34. 34*

    Quark condensate and chiral symmetry restoration in neutron stars

    Hao-Miao Jin🇨🇳 · Cheng-Jun Xia🇨🇳 · Ting-Ting Sun🇨🇳 · Guang-Xiong Peng🇨🇳

    Based on an equivparticle model, we investigate the in-medium quark condensate in neutron stars. Carrying out a Taylor expansion of the nuclear binding energy to the order of ${\rho }^3$, we obtain a series of EOSs for neutron star matter, which are confronted with the latest nuclear and astrophysical constraints. The in-medium quark condensate is then extracted from the constrained properties of neutron star matter, which decreases non-linearly with density. However, the chiral symmetry is only partially restored with non-vanishing quark condensates, which may vanish at a density that is out of reach for neutron stars.

    ↳ nucl-thhep-phPLB(2022)·11 citations
35. 35*

    Limitations of an Effective Field Theory Treatment of Early Universe Cosmology

    Robert Brandenberger (McGill University)🇨🇦

    Assuming that superstring theory is the fundamental theory which unifies all forces of Nature at the quantum level, I argue that there are key limitations on the applicability of effective field theory techniques in describing early universe cosmology.

    ↳ hep-thastro-ph.COgr-qchep-phPhil.Trans.Roy.Soc.Lond.A(2022)·9 citations
36. 36*

    An overview of ${\eta }_c(1S)$, ${\eta }_c(2S)$ and $h_c(1P)$ physics at BESIII

    Qingping Ji (1)🇨🇳 · Shuangshi Fang (2)🇨🇳 · Zhiyong Wang (2) ((1) Institution One, (2) Institution Two)🇨🇳

    With the help of the largest data samples of $J/\psi$ and $\psi (2S)$ events ever produced in $e^{+}{e}^{-}$ annihilations, the three singlet charmonium states, ${\eta }_c(1S)$, ${\eta }_c(2S)$ and $h_c(1P)$, have been extensively studied at the BESIII experiment. In this review, a survey on the most recent results, including a series of precision measurements and observations of their new decay modes, is presented, which indicates the further investigations on their decays are needed to understand their decay mechanisms and have precision tests of the theoretical models. At present, about eight times larger data samples of 10 billion $J/\psi$ events and 3 billion $\psi (3686)$ events were collected with the BESIII detector, and thus the prospects for the study of these three charmonium states is discussed extensively.

    ↳ hep-exhep-ph2 citations
37. 37*

    Relativistic hybrid stars in light of the NICER PSR J0740+6620 radius measurement

    Jia Jie Li (Southwest U., Chongqing)🇨🇳 · Armen Sedrakian (FIAS, Frankfurt)🇩🇪 · Mark Alford (Washington U., St. Louis)🇺🇸

    We explore the implications of the recent radius determination of PSR J0740+6620 by the NICER experiment combined with the neutron skin measurement by the PREX-II experiment and the associated inference of the slope of symmetry energy, for the structure of hybrid stars with a strong first-order phase transition from nucleonic to quark matter. We combine a covariant density-functional nucleonic equation of state (EOS) with a constant-speed-of-sound EOS for quark matter. We show that the radius and tidal deformability ranges obtained from GW170817 can be reconciled with the implication of the PREX-II experiment if there is a phase transition to quark matter in the low-mass compact star. In the high-mass segment, the EoS needs to be stiff to comply with the large-radius inference for PSR J0740+6620 and J0030+0451 with masses $M\simeq 2M_{\odot }$ and $M\simeq 1.4M_{\odot }$. We show that twin stars are not excluded, but the mass and radius ranges (with $M\ge M_{\odot }$) are restricted to narrow domains $\Delta M_{\mathrm{twin}}\lesssim 0.05M_{\odot }$ and $\Delta R_{\mathrm{twin}}\sim 1.0$~km. We also show that the existence of twin configurations is compatible with the light companion in the GW190814 event being a hybrid star in the case of values of the sound-speed square $s=0.6$ and $s=1/3$.

    ↳ astro-ph.HEhep-phnucl-thPRD(2021)·68 citations
38. 38*

    On Larger $H_0$ Values in the CMB Dipole Direction

    Orlando Luongo🇮🇹 · Marco Muccino🇰🇿 · Eoin Ó Colgáin🇰🇷 · M. M. Sheikh-Jabbari🇮🇷 · Lu Yin🇰🇷

    On the assumption that quasars (QSO) and gamma-ray bursts (GRB) represent \textit{standardisable candles}, we provide evidence that the Hubble constant $H_0$ adopts larger values in hemispheres aligned with the CMB dipole direction. If substantiated, this trend signals a departure from FLRW cosmology. In particular, QSOs show a definite trend, whereas our findings in GRBs are consistent with an isotropic Universe, but we show in a sample of GRBs calibrated with Type Ia supernovae (SN) that this conclusion may change as one focuses on GRBs more closely (mis)aligned with the CMB dipole direction. The statistical significance in QSOs alone is $\gtrsim 2\sigma$ and when combined with similar trends in strong lensing, Type Ia SN and calibrated GRBs, this increases to $\sim 3\sigma$. Our findings are consistent with reported discrepancies in the cosmic dipole and anisotropies in galaxy cluster scaling relations. The reported variations in $H_0$ across the sky suggest that Hubble tension may be a symptom of a deeper cosmological malaise.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2022)·135 citations
39. 39*

    High order quark number susceptibilities in hot QCD from lattice EQCD

    Kari Rummukainen🇫🇮 · Niels Schlusser🇫🇮

    Building on the experience of [1], we develop a formalism to construct operators for higher derivatives of the pressure in hot QCD with respect to the quark chemical potential $\mu$. We provide formulae for the operators up to the sixth derivative, and obtain continuum-extrapolated results from lattice EQCD at zero and finite $\mu$ and at six different pairs of temperature T and number of massless quark flavors $n_f$. Our data is benchmarked against full-QCD lattice and perturbative results, allowing to judge the quality of the perturbative series expansion in EQCD and the dimensional reduction procedure as a whole.

    ↳ hep-lathep-phPRD(2022)·1 citation
40. 40*

    Axion Quality Problem Alleviated by Non-Minimal Coupling to Gravity

    Koichi Hamaguchi🇯🇵 · Yoshiki Kanazawa🇯🇵 · Natsumi Nagata🇯🇵

    Global symmetries are expected to be violated by gravity, which may cause a serious problem to models based on these symmetries. A famous example is the Peccei-Quinn solution to the strong CP problem in QCD axion models; it requires a global U(1) symmetry to be respected with high quality, and even the Planck-scale suppressed operators that violate the U(1) symmetry would spoil this solution. Indeed, it is known that gravitational instantons do break the U(1) Peccei-Quinn symmetry and induce the U(1)-violating operators, bringing back the strong CP problem to the axion models. This conclusion is, however, dependent highly on the structure of the theory around the Planck scale and, therefore, may be evaded if we go beyond the minimal setup. In this paper, we study the effect of a non-minimal coupling of the Peccei-Quinn field to gravity, $\xi$, on the gravitational instanton effect. This setup is frequently considered in cosmology as it can realize a successful inflation if $\xi \lesssim 10^5$. We find that the U(1)-breaking effect of the gravitational instantons can sufficiently be suppressed for $\xi \gtrsim 2\times 10^3$, which suggests that the U(1) symmetry may be maintained with high quality even in the presence of gravity. Our result thus points to a new way to avoid the quality problem of global symmetries.

    ↳ hep-thhep-phPRD(2022)·20 citations
41. 41*

    21-cm constraints on spinning primordial black holes

    Junsong Cang🇨🇳 · Yu Gao🇨🇳 · Yin-Zhe Ma🇿🇦

    Hawking radiation from primordial black holes (PBH) can ionize and heat up neutral gas during the cosmic dark ages, leaving imprints on the global 21-cm signal of neutral hydrogen. We use the global 21-cm signal to constrain the abundance of spinning PBHs in mass range of $[2\times 10^{13},10^{18}]$ grams. We consider several extended PBH distribution models. Our results show that 21-cm can set the most stringent PBH bounds in our mass window. Compared with constraints set by {\it Planck} cosmic microwave background (CMB) data, 21-cm limits are more stringent by about two orders of magnitudes. PBHs with higher spin are typically more strongly constrained. Our 21-cm constraints for the monochromatic mass distribution rule out spinless PBHs with initial mass below $1.5\times 10^{17}\mathring{g}$, whereas extreme Kerr PBHs with reduced initial spin of $a_0=0.999$ are excluded as the dominant dark matter component for masses below $6\times 10^{17}\mathring{g}$. We also derived limits for the log-normal, power-law and critical collapse PBH mass distributions.

    ↳ astro-ph.COhep-phJCAP(2022)·48 citations
42. 42*

    Primitive Quantum Gates for Dihedral Gauge Theories

    M. Sohaib Alam🇺🇸 · Stuart Hadfield🇺🇸 · Henry Lamm🇺🇸 · Andy C. Y. Li🇺🇸

    We describe the simulation of dihedral gauge theories on digital quantum computers. The nonabelian discrete gauge group $D_N$ -- the dihedral group -- serves as an approximation to $U(1)\times {\mathbb{Z}}_2$ lattice gauge theory. In order to carry out such a lattice simulation, we detail the construction of efficient quantum circuits to realize basic primitives including the nonabelian Fourier transform over $D_N$, the trace operation, and the group multiplication and inversion operations. For each case the required quantum resources scale linearly or as low-degree polynomials in $n=\log N$. We experimentally benchmark our gates on the Rigetti Aspen-9 quantum processor for the case of $D_4$. The fidelity of all $D_4$ gates was found to exceed $80\%$.

    ↳ quant-phhep-lathep-phPRD(2022)·71 citations
43. 43*

    Dark Matter, Rotation Curves, and the Morphology of Galaxies

    Kirill Zatrimaylov🇮🇹

    In this thesis, we investigate some aspects of dark matter phenomenology and its predictive power in explaining the flattening of galaxy rotation curves at large distances. After outlining the Standard Model of particle physics, its symmetries and possible extensions in Chapter 2, we review key facts about dark matter and various types of dark matter models in Chapter 3. In Chapter 4 we discuss some alternatives to cold dark matter, which include modified Newtonian dynamics (MOND), superfluid dark matter and emergent gravity, and highlight the difficulties that are encountered in attempts to extend these frameworks to full-fledged relativistic settings. In Chapter 5 we turn to explore a completely different option, namely that flattened rotation curves reflect the presence of prolate dark-matter bulges or string-like objects around galaxies, without the need for any infrared modification of gravity. To test this model, we fit a number of galaxy rotation curves and find that the presence of a string-like filament yields improvement in fit quality of about 40-70 % in some cases, while the deformation of a dark halo yields only modest improvement by about 6-7 %. In Chapter 6 we collect some concluding remarks.

    ↳ astro-ph.COastro-ph.GAgr-qchep-ph+11 citation
44. 44*

    Detecting Axion Dark Matter through the Radio Signal from Omega Centauri

    Jin-Wei Wang🇮🇹 · Xiao-Jun Bi🇨🇳 · Peng-Fei Yin🇨🇳

    As a well-motivated dark matter candidate, axions can be detected through the axion-photon resonant conversion in the magnetospheres of magnetic white dwarf stars or neutron stars. In this work, we utilize Omega Centauri, which is the largest globular cluster in the Milky Way and is suggested to be the remnant core of a dwarf galaxy, to probe the axion dark matter through radio signals that originate from all the neutron stars and magnetic white dwarf stars in it. With 100 hours of observation, the combination of SKA phase 1 and LOFAR can effectively probe the parameter space of the axion-photon coupling $g_{a\gamma }$ up to $10^{-14}\sim 10^{-15}{\text{GeV}}^{-1}$ for the axion mass range of $0.1\sim 30\mu \text{eV}$. Depending on the choice of neutron star evolution model, this limitation is two or three and a half orders of magnitude higher than that of the single neutron star or magnetic white dwarf.

    ↳ astro-ph.HEhep-phPRD(2021)·21 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.