Tue·Sep 1, 2020Tuesday·September 1, 2020

1. 01*

   CP violation in neutral lepton transition dipole moment

   Shyam Balaji🇦🇺 · Maura Ramirez-Quezada🇬🇧 · Ye-Ling Zhou🇬🇧

   The $CP$ violation in the neutrino transition electromagnetic dipole moment is discussed in the context of the Standard Model with an arbitrary number of right-handed singlet neutrinos. A full one-loop calculation of the neutrino electromagnetic form factors is performed in the Feynman gauge. A non-zero $CP$ asymmetry is generated by a required threshold condition for the neutrino masses along with non-vanishing $CP$ violating phases in the lepton flavour mixing matrix. We follow the paradiagm of $CP$ violation in neutrino oscillations to parametrise the flavour mixing contribution into a series of Jarlskog-like parameters. This formalism is then applied to a minimal seesaw model with two heavy right-handed neutrinos denoted $N_1$ and $N_2$. We observe that the $CP$ asymmetries for decays into light neutrinos $N\to \nu \gamma$ are extremely suppressed, maximally around $10^{-17}$. However the $CP$ asymmetry for $N_2\to N_1\gamma$ can reach of order unity. Even if the Dirac $CP$ phase $\delta$ is the only source of $CP$ violation, a large $CP$ asymmetry around $10^{-5}$-$10^{-3}$ is comfortably achieved.

   hep-phJHEP(2020)·29 citations
2. 02*

   Kinematical Cusp and Resonance Interpretations of the $X(2900)$

   T.J. Burns🇬🇧 · E.S. Swanson🇺🇸

   We examine whether the LHCb vector $ud\bar{c}\bar{s}$ state $X(2900)$ can be interpreted as a kinematical cusp effect arising from ${\bar{D}}^{\ast }{K}^{\ast }$ and ${\bar{D}}_1{K}^{\ast }$ interactions. The production amplitude is modelled as a triangle diagram with hadronic final state interactions. A satisfactory fit to the Dalitz plot projection is obtained that leverages the singularities of the production diagram without the need for $\bar{D}K$ resonances. A somewhat better fit is obtained if the final state interactions are strong enough to generate resonances, although the evidence in favour of this scenario is not conclusive.

   hep-phPLB(2021)·58 citations
3. 03*

   Deep inelastic vortex scattering: A third outcome for head-on collisions

   Ethan P. Honda🇺🇸

   Results are presented from numerical simulations of the flat-space nonlinear Maxwell-Klein-Gordon equations demonstrating deep inelastic scattering of $m=1$ vortices for a range of Ginzburg-Landau (or Abelian-Higgs) parameters ($\kappa$), impact parameters ($b$), and initial velocities ($v_0$). The threshold ($v_0^{\ast }$) of right-angle scattering is explored for head-on ($b=0$) collisions by varying $v_0$. Solutions obey time-scaling laws, $T\propto \alpha \ln (v_0-v_0^{\ast })$, with $\kappa$-dependent scaling exponents, $\alpha$, and have $v_0^{\ast }$ that appear not to have the previously reported upper bound. The arbitrarily long-lived static intermediate attractor at criticality ($v_0=v_0^{\ast }$) is observed to be the $\kappa$-specific $m=2$ vortex solution. Scattering angles are observed for off-axis ($b\ne 0$) collisions for a wide range of $b$, $v_0$, and $\kappa$. It is shown that for arbitrarily small impact parameters ($b\to 0$), the unstable %but arbitrarily long-lived $\kappa$-dependent $m=2$ "critical" vortex is an intermediate attractor and decays with a $\kappa$-\emph{independent} scattering angle of $135^{\circ }$, as opposed to either of the well-known values of $180^{\circ }$ or $90^{\circ }$ for $b=0$.

   hep-phcond-mat.supr-congr-qcPRD(2020)·2 citations
4. 04*

   Bending of light in axion backgrounds

   Jamie I. McDonald🇩🇪 · Luís B. Ventura🇵🇹

   In this work we examine refraction of light by computing full solutions to axion electrodynamics. We also allow for the possibility of an additional plasma component. We then specialise to wavelengths which are small compared to background scales to determine if refraction can be described by geometric optics. We also allow for the possibility of an additional plasma component. In the absence of plasma, for small incidence angles relative to the optical axis, axion electrodynamics and geometric optics are in good agreement, with refraction occurring at $\mathcal{O}(g_{a\gamma \gamma }^2)$. However, for rays which lie far from the optical axis, the agreement with geometric optics breaks down and the dominant refraction requires a full wave-optical treatment, occurring at $\mathcal{O}(g_{a\gamma \gamma })$. In the presence of sufficiently large plasma masses, the wave-like nature of light becomes suppressed and geometric optics is in good agreement with the full theory for all rays. Our results therefore suggest the necessity of a more comprehensive study of lensing and ray-tracing in axion backgrounds, including a full account of the novel $\mathcal{O}(g_{a\gamma \gamma })$ wave-optical contribution to refraction.

   hep-phgr-qc14 citations
5. 05*

   On the W&Y interpretation of high-energy Drell-Yan measurements

   Lorenzo Ricci🇨🇭 · Riccardo Torre🇨🇭 · Andrea Wulzer🇨🇭

   High-energy neutral and charged Drell--Yan differential cross-section measurements are powerful probes of quark-lepton contact interactions that produce growing-with-energy effects. This paper provides theoretical predictions of the new physics effects at the Next-to-Leading order in QCD and including one-loop EW corrections at the single-logarithm accuracy. The predictions are obtained from SM Monte Carlo simulations through analytic reweighting. This eliminates the need of performing a scan on the new physics parameter space, enabling the global exploration of all the relevant interactions. Furthermore, our strategy produces consistently showered events to be employed for a direct comparison of the new physics predictions with the data, or to validate the unfolding procedure than underlies the cross-section measurements. Two particularly relevant interactions, associated with the W and Y parameters of EW precision tests, are selected for illustration. Projections are presented for the sensitivity of the LHC and of the HL-LHC measurements. The impact on the sensitivity of several sources of uncertainties is quantified.

   hep-phhep-exJHEP(2021)·61 citations
6. 06*

   Electroweak Corrections in a Pseudo-Nambu Goldstone Dark Matter Model Revisited

   Seraina Glaus🇩🇪 · Margarete Mühlleitner🇩🇪 · Jonas Müller🇩🇪 · Shruti Patel🇩🇪 · Tizian Römer🇩🇪 · Rui Santos🇵🇹

   Having so far only indirect evidence for the existence of Dark Matter a plethora of experiments aims at direct detection of Dark Matter through the scattering of Dark Matter particles off atomic nuclei. For the correct interpretation and identification of the underlying nature of the Dark Matter constituents higher-order corrections to the cross section of Dark Matter-nucleon scattering are important, in particular in models where the tree-level cross section is negligibly small. In this work we revisit the electroweak corrections to the dark matter-nucleon scattering cross section in a model with a pseudo Nambu-Goldstone boson as the Dark Matter candidate. Two calculations that already exist in the literature, apply different approaches resulting in different final results for the cross section in some regions of the parameter space leading us to redo the calculation and analyse the two approaches to clarify the situation. We furthermore update the experimental constraints and examine the regions of the parameter space where the cross section is above the neutrino floor but which can only be probed in the far future.

   hep-phJHEP(2020)·34 citations
7. 07*

   Probing the Top-Higgs Sector with Composite Higgs Models at Present and Future Hadron Colliders

   Carlos Bautista🇧🇷 · Leonardo de Lima🇧🇷 · Ricardo D. Matheus🇧🇷 · Eduardo Pontón🇧🇷 · Leônidas A. F. do Prado🇧🇷 · Aurore Savoy-Navarro🇫🇷

   We study the production of $t\bar{t}h$ and $t\bar{t}hh$ at hadron colliders, in the minimal Composite Higgs Models, based on the coset $SO(5)/SO(4)$. We explore the fermionic representations $5$ and $14$. A detailed phenomenological analysis is performed, covering the energy range of the LHC and its High Luminosity upgrade, as well as that of a future 100 TeV hadron collider. Both resonant and non-resonant production are considered, stressing the interplay and complementary interest of these channels with each other and double Higgs production. We provide sets of representative points with detailed experimental outcomes in terms of modification of the cross sections as well as resonance masses and branching ratios. For non-resonant production, we gauge the relative importance of Yukawa, Higgs trilinear, and contact $t\bar{t}hh$ vertices to these processes, and consider the prospect for distinguishing the fermion representations from each other and from the Standard Model. In the production of top partners, we find that the three-body decay channel $W^{+}{W}^{-}t$ becomes significant in certain regions of parameter space having a degenerate spectrum, and is further enhanced with energy. This motivates both higher energy machines as well as the need to go beyond the current analysis performed for the searches for these resonances.

   hep-phhep-exJHEP(2021)·7 citations
8. 08*

   New scalar resonance $X_0(2900)$ as a ${\overline{D}}^{\ast }{K}^{\ast }$ molecule: Mass and width

   S. S. Agaev🇦🇿 · K. Azizi🇮🇷 · H. Sundu🇹🇷

   We explore features of the scalar structure $X_0(2900)$, which is one of the two resonances discovered recently by LHCb in the $D^{-}{K}^{+}$ invariant mass distribution in the decay $B^{+}\to D^{+}{D}^{-}{K}^{+}$. We treat $X_0(2900)$ as a hadronic molecule composed of the conventional mesons ${\overline{D}}^{\ast 0}$ and $K^{\ast 0}$ and calculate its mass, coupling and width. The mass and coupling of $X_0(2900)$ are determined using the QCD two-point sum rule method by taking into account quark, gluon, and mixing vacuum condensates up to dimension $15$. The decay of this structure to final state $D^{-}{K}^{+}$ is investigated in the context of the light-cone sum rule approach supported by a soft-meson technique. To this end, we evaluate strong coupling $G$ corresponding to vertex $X_0{D}^{-}{K}^{+}$, which allows us to find width of the decay $X_0(2900)\to D^{-}{K}^{+}$. Obtained predictions for the mass of the hadronic molecule ${\overline{D}}^{\ast 0}{K}^{\ast 0}$ $m=(2868\pm 198)\mathrm{MeV}$ and for its width $\Gamma =(49.6\pm 9.3)\mathrm{MeV}$ can be considered as arguments in favor of molecule interpretation of $X_0(2900)$.

   hep-phhep-exhep-latJ.Phys.G(2021)·73 citations
9. 09*

   Dark mesons as self-interacting dark matter

   Hyun Min Lee🇰🇷

   We review the current status of model building for light dark matter in theories of QCD-like gauge groups in the hidden sector. The focus is upon the dark mesons with the $SU(3{)}_V$ flavor symmetry in scenarios of Strongly Interacting Massive Particles. We show the production mechanism and the kinetic equilibrium condition for dark mesons and discuss a unitarization of dark chiral perturbation theory with vector mesons in the scheme of hidden gauge symmetry.

   hep-phEur.Phys.J.ST(2022)·6 citations
10. 10*

    Enhancement of low-mass dileptons in ultraperipheral collisions

    I.M. Dremin🇷🇺 · S.R. Gevorkyan🇷🇺 · D.T. Madigozhin🇷🇺

    It is shown that production of low-mass $e^{+}{e}^{-}$-pairs in ultraperipheral nuclear collisions is enhanced due to the Sommerfeld-Gamow-Sakharov (SGS) factor. This effect is especially strong near the threshold of creation of unbound $e^{+}{e}^{-}$-pairs with low masses in the two-photon fusion. Coulomb attraction of the non-relativistic components of such pairs may lead to the increased intensity of 511 keV photons. It can be recorded at the NICA collider and has some astrophysical implications. The analogous effect can be observed at LHC in dilepton production.

    hep-phastro-ph.HEhep-exnucl-ex+1EPJC(2021)·8 citations
11. 11*

    IBP reduction coefficients made simple

    Janko Boehm🇩🇪 · Marcel Wittmann🇩🇪 · Zihao Wu🇨🇳 · Yingxuan Xu🇨🇭 · Yang Zhang🇨🇳

    We present an efficient method to shorten the analytic integration-by-parts (IBP) reduction coefficients of multi-loop Feynman integrals. For our approach, we develop an improved version of Leinartas' multivariate partial fraction algorithm, and provide a modern implementation based on the computer algebra system Singular. Furthermore, We observe that for an integral basis with uniform transcendental (UT) weights, the denominators of IBP reduction coefficients with respect to the UT basis are either symbol letters or polynomials purely in the spacetime dimension $D$. With a UT basis, the partial fraction algorithm is more efficient both with respect to its performance and the size reduction. We show that in complicated examples with existence of a UT basis, the IBP reduction coefficients size can be reduced by a factor of as large as $\sim 100$. We observe that our algorithm also works well for settings without a UT basis.

    hep-phhep-thmath.AGJHEP(2020)·61 citations
12. 12*

    Gradient tomography of jet quenching in high-energy heavy-ion collisions

    Yayun He🇨🇳 · Longgang Pang🇨🇳 · Xin-Nian Wang🇨🇳

    We illustrate with both a Boltzmann diffusion equation and full simulations of jet propagation in heavy-ion collisions within the Linear Boltzmann Transport (LBT) model that the spatial gradient of the jet transport coefficient perpendicular to the propagation direction can lead to a drift and asymmetry in the transverse momentum distribution. Such an asymmetry depends on both the spatial position along the transverse gradience and the propagating length. It can be used to localize the initial jet production positions for more detailed studies of jet quenching and properties of the quark-gluon plasma in heavy-ion collisions.

    hep-phnucl-thPoS(2021)·1 citation
13. 13*

    Inflation and long-range force from clockwork $D$-term

    Anjan S. Joshipura🇮🇳 · Subhendra Mohanty🇮🇳 · Ketan M. Patel🇮🇳

    Cosmic inflation driven by the vacuum energy associated with the $D$-term of a supersymmetric abelian gauge group and a possible existence of long-range force mediated by an ultra-light gauge boson $Z^{\prime }$ are two extreme examples of models based on extra $U(1)$ symmetries. Large vacuum energy sets the scale of inflation while the scales of long-range forces induced by anomaly free extra gauged $U(1)$ symmetries are constrained by neutrino oscillations, binary pulsar timings and invisible neutrino decay. There exists a difference of about 40 orders of magnitude between the scales of these two. Also, gauge couplings associated with the long-range forces are very small compared to the standard model couplings and the one required for inflation. We propose a framework based on clockwork mechanism in which these vastly different scales and associated new physics can coexist without invoking any arbitrarily small or large parameter in the fundamental theory. A chain of $U(1)$ is introduced with characteristic nearest-neighbour interactions. A large $D$-term introduced at one end governs the dynamics of inflation. $Z^{\prime }$ is localized on the other end of the chain, and it can be massless or can get naturally suppressed mass. The standard model fields can be charged under one of the intermediate $U(1)$ in the chain to give rise to their small effective coupling $g^{\prime }$ with $Z^{\prime }$. Constraints on $g^{\prime }$ and $M_{Z^{\prime }}$ are discussed in the context of the long-range forces of type $L_{\mu }-L_{\tau }$, $L_e-L_{\mu }$ and $B-L$. These, along with the inflation observables, are used to constraint the parameters of the underlying clockwork model.

    hep-phgr-qcPRD(2021)·7 citations
14. 14*

    Charge asymmetry in decays $B\to D\bar{D}K$

    A.E. Bondar🇷🇺 · A.I. Milstein🇷🇺

    We discusses the charge asymmetry in $B\to D\bar{D}K$ decays with an invariant mass of the $D\bar{D}$ pair near the $\Psi (3770)$ resonance. Unlike $\Psi (3770)$ decays in $e^{+}{e}^{-}$ annihilation, in $B^{+}$ decays the probability of $D^0{\bar{D}}^0$ production is almost three times higher than $D^{+}{D}^{-}$. In $B^0$ decays, the ratio of these probabilities will be opposite. The effect is explained by the fact that, in $B$ -meson decays, the $D\bar{D}$ pair is produced in a superposition of isoscalar and isovector states, and only in combination with $K$ -mesons the total state has $1/2$ isospin. We present a simple model in which the interference of the nonresonant isovector amplitude with the resonant isoscalar amplitude explains the experimental data.

    hep-phhep-exJHEP(2020)·11 citations
15. 15*

    Near-threshold photoproduction of $J/\psi$ in two-gluon exchange model

    Fancong Zeng🇨🇳 · Xiao-Yun Wang · Li Zhang🇨🇳 · Ya-Ping Xie🇨🇳 · Rong Wang🇨🇳 · Xurong Chen🇨🇳

    The near-threshold photoproduction of $J/\psi$ is regarded as one golden process to unveil the nucleon mass structure, pentaquark state involving the charm quarks, and the poorly constrained gluon distribution of the nucleon at large $x$ ($>0.1$). In this paper, we present an analysis of the current experimental data under a two-gluon exchange model, which shows a good consistency. Using a parameterized function form with three free parameters, we have determined the nucleonic gluon distribution at the $J/\psi$ mass scale. Moreover, we predict the differential cross section of the electroproduction of $J/\psi$ as a function of the invariant mass of the final hadrons $W$, at EicC, as a practical application of the model and the obtained gluon distribution. According to our estimation, thousands of $J/\psi$ events can be detected per year on EicC near the threshold. Therefore, the relevant experimental measurements are suggested to be carried out on EicC.

    hep-phnucl-thEPJC(2020)·21 citations
16. 16*

    A New Observable for Measuring CP Property of Top-Higgs Interaction

    Qing-Hong Cao🇨🇳 · Ke-Pan Xie🇰🇷 · Hao Zhang🇨🇳 · Rui Zhang🇨🇳

    We propose a new dihedral angle observable to measure the CP property of the interaction of top quark and Higgs boson in the $t\bar{t}H$ production at the 14~TeV LHC. We consider two decay modes of the Higgs boson, $H\to b\bar{b}$ and $H\to \gamma \gamma$ and show that the dihedral angle distribution is able to distinguish the CP-even and the CP-odd hypothesis at 95\% confidence level with an integrated luminosity of $\sim 180{\mathrm{fb}}^{-1}$.

    hep-phhep-exCPC(2021)·27 citations
17. 17*

    Evidence of shadowing in inelastic nucleon-nucleon cross section

    Kari J. Eskola🇫🇮 · Ilkka Helenius🇫🇮 · Mikko Kuha🇫🇮 · Hannu Paukkunen🇫🇮

    The Glauber modeling plays a key role in centrality-dependent measurements of heavy-ion collisions. A central input parameter in Glauber models is the inelastic nucleon-nucleon cross section ${\sigma }_{\text{nn}}^{\text{inel}}$ which is nearly always taken from proton-proton measurements. At the LHC energies ${\sigma }_{\text{nn}}^{\text{inel}}$ depends on the QCD dynamics at small $x$ and low interaction scales where the shadowing/saturation phenomena are expected to become relatively more important for larger nuclei than for the proton. Thus, ${\sigma }_{\text{nn}}^{\text{inel}}$ e.g. in Pb+Pb collisions may well be lower than what is seen in proton-proton collisions. In this talk, we demonstrate how to use the recent $W^{\pm }$ and $Z$ measurements as a "standard candle" to extract ${\sigma }_{\text{nn}}^{\text{inel}}$ in Pb+Pb collisions. Our analysis -- built on the ATLAS data, state-of-the-art NNLO QCD calculations and nuclear PDFs -- indicate that at the LHC energies ${\sigma }_{\text{nn}}^{\text{inel}}$ in Pb+Pb collisions is suppressed relative to the proton-proton measurements by tens of percents. We demonstrate that this is in line with expectations from nuclear PDFs.

    hep-phnucl-thPoS(2021)·2 citations
18. 18*

    $X_{0,1}$(2900) and $(D^{-}{K}^{+})$ invariant mass from QCD Laplace sum rules at NLO

    R.M. Albuquerque🇧🇷 · S. Narison🇫🇷 · D. Rabetiarivony🇲🇬 · G. Randriamanatrika🇲🇬

    We revisit, improve and complete some recent estimates of the $0^{+}$ and $1^{-}$ open charm $(\bar{c}\bar{d})(us)$ tetraquarks and the corresponding molecules masses and decay constants from QCD spectral sum rules (QSSR) by using QCD Laplace sum rule (LSR) within stability criteria where the factorised perturbative NLO corrections and the contributions of quark and gluon condensates up to dimension-6 in the OPE are included. We confront our results with the $D^{-}{K}^{+}$ invariant mass recently reported by LHCb from $B^{+}\to D^{+}(D^{-}{K}^{+})$ decays. We expect that the bump near the $D^{-}{K}^{+}$ threshold can be originated from the $0^{++}(D^{-}{K}^{+})$ molecule and/or $D^{-}{K}^{+}$ scattering. The prominent $X_0$(2900) scalar peak and the bump $X_J(3150)$ (if $J=0$) can emerge from a {\it minimal mixing model}, with a tiny mixing angle ${\theta }_0\simeq (5.2\pm 1.9{)}^0$, between a scalar {\it Tetramole} (${{\mathcal{T}}_{\mathcal{M}}}_0$) (superposition of nearly degenerated hypothetical molecules and compact tetraquarks states with the same quantum numbers) having a mass $M_{{{\mathcal{T}}_{\mathcal{M}}}_0}$=2743(18) MeV and the first radial excitation of the $D^{-}{K}^{+}$ molecule with mass $M_{(DK{)}_1}=3678(310)$ MeV. In an analogous way, the $X_1$(2900) and the $X_J(3350)$ (if $J=1$) could be a mixture between the vector {\it Tetramole} $({{\mathcal{T}}_{\mathcal{M}}}_1)$ with a mass $M_{{{\mathcal{T}}_{\mathcal{M}}}_1}=2656(20)$ MeV and its first radial excitation having a mass $M_{({{\mathcal{T}}_{\mathcal{M}}}_1{)}_1}=4592(141)$ MeV with an angle ${\theta }_1\simeq (9.1\pm 0.6{)}^0$. A (non)-confirmation of the previous {\it minimal mixing models} requires an experimental identification of the quantum numbers of the bumps at 3150 and 3350 MeV.

    hep-phhep-exhep-latnucl-thNPA(2021)·58 citations
19. 19*

    Exotic double-charm molecular states with hidden or open strangeness and around $4.5\sim 4.7$ GeV

    Fu-Lai Wang🇨🇳 · Xiang Liu🇨🇳

    In this work, we investigate the interactions between the charmed-strange meson ($D_s,D_s^{\ast }$) in $H$-doublet and the (anti-)charmed-strange meson ($D_{s1},D_{s2}^{\ast }$) in $T$-doublet, where the one boson exchange model is adopted by considering the $S$-$D$ wave mixing and the coupled-channel effects. By extracting the effective potentials for the discussed $H_s{\bar{T}}_s$ and $H_s{T}_s$ systems, we try to find the bound state solutions for the corresponding systems. We predict the possible hidden-charm hadronic molecular states with hidden strangeness, i.e., the $D_s^{\ast }{\bar{D}}_{s1}+c.c.$ states with $J^{PC}$=$0^{--},0^{-+}$ and the $D_s^{\ast }{\bar{D}}_{s2}^{\ast }+c.c.$ states with $J^{PC}$=$1^{--},1^{-+}$. Applying the same theoretical framework, we also discuss the $H_s{T}_s$ systems. Unfortunately, the existence of the open-charm and open-strange molecular states corresponding to the $H_s{T}_s$ systems can be excluded.

    hep-phPRD(2020)·31 citations
20. 20*

    Short-distance HLbL contributions to the muon anomalous magnetic moment beyond perturbation theory

    Johan Bijnens (Lund)🇸🇪 · Nils Hermansson-Truedsson (Berne)🇨🇭 · Laetitia Laub (Berne)🇨🇭 · Antonio Rodríguez-Sánchez (Lund)🇸🇪

    The hadronic light-by-light contribution to the muon anomalous magnetic moment depends on an integration over three off-shell momenta squared ($Q_i^2$) of the correlator of four electromagnetic currents and the fourth leg at zero momentum. We derive the short-distance expansion of this correlator in the limit where all three $Q_i^2$ are large and in the Euclidean domain in QCD. This is done via a systematic operator product expansion (OPE) in a background field which we construct. The leading order term in the expansion is the massless quark loop. We also compute the non-perturbative part of the next-to-leading contribution, which is suppressed by quark masses, and the chiral limit part of the next-to-next-to leading contributions to the OPE. We build a renormalisation program for the OPE. The numerical role of the higher-order contributions is estimated and found to be small.

    hep-phJHEP(2020)·112 citations
21. 21*

    Reconstructing boosted Higgs jets from event image segmentation

    Jinmian Li🇨🇳 · Tianjun Li🇨🇳 · Fang-Zhou Xu🇨🇳

    Based on the jet image approach, which treats the energy deposition in each calorimeter cell as the pixel intensity, the Convolutional neural network (CNN) method has been found to achieve a sizable improvement in jet tagging compared to the traditional jet substructure analysis. In this work, the Mask R-CNN framework is adopted to reconstruct Higgs jets in collider-like events, with the effects of pileup contamination taken into account. This automatic jet reconstruction method achieves higher efficiency of Higgs jet detection and higher accuracy of Higgs boson four-momentum reconstruction than traditional jet clustering and jet substructure tagging methods. Moreover, the Mask R-CNN trained on events containing a single Higgs jet is capable of detecting one or more Higgs jets in events of several different processes, without apparent degradation in reconstruction efficiency and accuracy. The outputs of the network also serve as new handles for the $t\bar{t}$ background suppression, complementing to traditional jet substructure variables.

    hep-phhep-exJHEP(2021)·25 citations
22. 22*

    The neutrino-floor in the presence of dark radation

    Marco Nikolic🇦🇹 · Suchita Kulkarni🇦🇹 · Josef Pradler🇦🇹

    In this work we analyse the ultimate sensitivity of dark matter direct detection experiments, the "neutrino-floor", in the presence of anomalous sources of dark radiation in form of SM or semi-sterile neutrinos. This flux-component is assumed to be produced from dark matter decay. Since dark radiation may mimic dark matter signals, we perform our analysis based on likelihood statistics that allows to test the distinguishability between signals and backgrounds. We show that the neutrino floor for xenon-based experiments may be lifted in the presence of extra dark radiation. In addition, we explore the testability of neutrino dark radiation from dark matter decay in direct detection experiments. Given the previous bounds from neutrino experiments, we find that xenon-based dark matter searches will not be able to probe new regions of the dark matter progenitor mass and lifetime parameter space when the decay products are SM neutrinos. In turn, if the decay instead happens to a fourth neutrino species with enhanced interactions to baryons, DR can either constitute the dominant background or a discoverable signal in direct detection experiments.

    hep-phEPJC(2022)·13 citations
23. 23*

    Lepton-pair production in hard exclusive hadron-hadron collisions

    S.V. Goloskokov🇷🇺 · P. Kroll🇩🇪 · O. Teryaev🇷🇺

    We investigate lepton-pair production in hard exclusive hadron-hadron collisions. We consider a double handbag (DH) mechanism in which the process amplitude factorizes in hard subprocesses, qq -> qq gamma* and qg -> qg gamma*, and in soft hadron matrix elements parameterized as generalized parton distributions (GPDs). Employing GPDs extracted from exclusive meson electroproduction, we present predictions for the lepton-pair cross section at kinematics typical for the LHC, NICA and FAIR. It turns out from our numerical studies that the quark-gluon subprocess dominates by far, the quark-quark (antiquark) subprocesses are almost negligible.

    hep-ph2 citations
24. 24*

    Cosmological particle creation in the little bang

    S.V. Akkelin🇺🇦

    Particle production by expanding in the future light cone scalar quantum field is studied by assuming that the initial state is associated with the quasiequilibrium statistical operator corresponding to fluid dynamics. We calculate particle production from a longitudinally boost-invariant expanding quantum field designed as a simple but reliable model for the central rapidity region of a relativistic collision. Exact diagonalization of the model is performed by introducing a notion of quasiparticles.

    hep-phhep-thnucl-thPRD(2021)·6 citations
25. 25*

    Examining the event-shape dependent modifications to charged-particle transverse momentum spectra and elliptic flow in p-Pb collisions at energies available at the CERN Large Hadron Collider

    Somnath Kar🇨🇳 · Subikash Choudhury🇨🇳 · Xiaoming Zhang🇨🇳 · Daicui Zhou🇨🇳

    Purported signatures of collective dynamics in small systems like proton-proton (pp) or proton-nucleus (p-A) collisions still lack unambiguous understanding. Despite the qualitative and/or quantitative agreement of the data to hydrodynamic models, it has remained unclear whether the harmonic flows in small systems relate to the common physical picture of hydrodynamic collectivity driven by the initial geometry. In the present work, we aim to address this issue by invoking a novel concept of Event Shape Engineering (ESE), which has been leveraged to get some control of the initial geometry in high-energy heavy-ion collisions. We utilise ESE by constructing a reference flow vector, $q_2$ that allows to characterise an event based on it's ellipticity. Applying this technique on a data set, simulated from a 3+1D viscous hydrodynamic model EPOS3, we study the event-shape dependent modifications to some of the bulk properties like, inclusive transverse momentum ($p_T$) spectra and $p_T$-differential $v_2$ for p-Pb collisions at 5.02 TeV. Selecting events on the basis of different magnitudes of reference flow vector $q_2$, we observe a hint of event-shape induced modifications of $v_2$ as a function of $p_T$ but, the inclusive $p_T$-spectra of charged particles seem to be insensitive to this event-shape selection.

    hep-phPRC(2020)·1 citation
26. 26*

    Neutrino and dark matter in a gauged $U(1{)}_R$ symmetry

    Keiko I. Nagao🇯🇵 · Hiroshi Okada🇰🇷

    We study neutrino and dark matter based on a gauged $U(1{)}_R$ symmetry in a framework of radiative seesaw scenario. Identifying dark matter as a bosoninc particle, it interacts with quark and lepton sectors through vector-like heavier quark and leptons, and plays an role in generating neutrino mass matrix together with neutral heavier fermions. We explore several constraints for masses and couplings related to dark matter by computing relic density and direct search, taking the neutrino oscillation, lepton flavor violations, and muon anomalous magnetic moment into account. Finally, we briefly mention semileptonic decays and neutral meson mixings at one-loop box diagrams through dark matter.

    hep-phJCAP(2021)·19 citations
27. 27*

    Quark-gluon plasma speed of sound in magnetic field

    Z.V.Khaidukov🇷🇺 · R.A.Abramchuk🇷🇺

    A non-perturbative method of Field Correlators (FCM) is applied to study speed of sound in quark-gluon plasma at temperatures above the deconfinement transition 1<T/T_c<3 (Tc=160 MeV) under a uniform magnetic field up to eB ~ 1 GeV^2. The speed of sound in N_f=2+1 QCD quark-gluon plasma is found to exceed the conformal limit (1/3) at very large magnetic field strengths eB>0.5 GeV^2. At large temperatures, the speed of sound tends to the conformal limit; low-temperature behavior demonstrates inverse magnetic catalysis. The effect of magnetic field on the speed of sound in quark-gluon plasma is found to be negligible in any existing Heavy Ion Collision experiment, including \sqrt{s_{NN}}=5.02 TeV Pb-Pb collisions at LHC.

    hep-ph1 citation
28. 28*

    High-Temperature Electroweak Symmetry Breaking by SM Twins

    Oleksii Matsedonskyi🇮🇱

    We analyse a possible adjustment of Twin Higgs models allowing to have broken electroweak (EW) symmetry at all temperatures below the sigma-model scale $\sim 1$TeV. The modification consists of increasing the Yukawa couplings of the twins of light SM fermions. The naturalness considerations then imply a presence of relatively light electroweak-charged fermions, which can be produced at the LHC, and decay into SM gauge and Higgs bosons and missing energy. Analysis of experimental bounds shows that such a modified model features an increased amount of fine-tuning compared to the original Twin Higgs models, but still less tuning than the usual pseudo-Nambu-Goldstone Higgs models not improved by $Z_2$ symmetry. The obtained modification in the evolution of the EW symmetry breaking strength can, in particular, have interesting implications for models of EW baryogenesis, which we comment on.

    hep-phJHEP(2021)·30 citations
29. 29*

    Uniting low-scale leptogeneses

    Juraj Klarić🇨🇭 · Mikhail Shaposhnikov🇨🇭 · Inar Timiryasov🇨🇭

    In this work we demonstrate that what was previously considered as different mechanisms of baryon asymmetry generation involving two right-handed Majorana neutrinos with masses far below the GUT scale -- leptogenesis via neutrino oscillations and resonant leptogenesis -- are actually united. We show that the observed baryon asymmetry can be generated for all experimentally allowed values of the right-handed neutrino masses above $M_N\gtrsim 100$ MeV. Leptogenesis is effective in a broad range of the parameters, including mass splitting between two right-handed neutrinos as big as $\Delta M_N/M_N\sim 0.1$, as well as mixing angles between the heavy and light neutrinos large enough to be accessible to planned intensity experiments or future colliders.

    hep-phPRL(2021)·104 citations
30. 30*

    The Strangest Proton?

    Ferran Faura🇳🇱 · Shayan Iranipour🇬🇧 · Emanuele R. Nocera🇳🇱 · Juan Rojo🇳🇱 · Maria Ubiali🇬🇧

    We present an improved determination of the strange quark and anti-quark parton distribution functions of the proton by means of a global QCD analysis that takes into account a comprehensive set of strangeness-sensitive measurements: charm-tagged cross sections for fixed-target neutrino-nucleus deep-inelastic scattering, and cross sections for inclusive gauge-boson production and $W$-boson production in association with light jets or charm quarks at hadron colliders. Our analysis is accurate to next-to-next-to leading order in perturbative QCD where available, and specifically includes charm-quark mass corrections to neutrino-nucleus structure functions. We find that a good overall description of the input dataset can be achieved and that a strangeness moderately suppressed in comparison to the rest of the light sea quarks is strongly favored by the global analysis.

    hep-phhep-exhep-latnucl-thEPJC(2020)·90 citations
31. 31*

    Heavy Quark Radiation in the Quark-Gluon Plasma in the Moliere Theory: Angular Distribution of the Radiation

    B. Blok (Technion)🇮🇱

    We study the effects of adding the Coulomb interactions to the harmonic oscillator (HO) approximation of the heavy parton propagating through the quark-gluon plasma (the extension to QCD of the Molliere theory). We explicitly find the expression for the transverse momentum distribution of the gluon radiation of the heavy quark propagating in the quark gluon plasma in the framework of the Moliere theory, taking into account the BDMPSZ radiation in the harmonic oscillator (HO) approximation, and the Coulomb logarithms described by the additional logarithmic terms in the effective potential. We show that these Coulomb logarithms significantly influence the HO distribution, derived in the BDMPSZ works, especially for the small transverse momenta, filling the dead cone, and reducing the dead cone suppression of the heavy quark radiation (dead cone effect). In addition we study the effect of the phase space constraints on the heavy quark energy loss, and argue that taking into account of both the phase space constraints and of the Coulomb gluons reduces the dependence of the heavy quark energy loss on its mas in the HO approximation.

    hep-phhep-exnucl-exnucl-thEPJC(2021)·8 citations
32. 32*

    Test for the Origin of Solar Mass Black Holes

    Volodymyr Takhistov🇺🇸 · George M. Fuller🇺🇸 · Alexander Kusenko🇺🇸

    Solar-mass black holes with masses in the range of $\sim 1-2.5M_{\odot }$ are not expected from conventional stellar evolution, but can be produced naturally via neutron star (NS) implosions induced by capture of small primordial black holes (PBHs) or from accumulation of some varieties of particle dark matter. We argue that a unique signature of such "transmuted" solar-mass BHs is that their mass distribution would follow that of the NSs. This would be distinct from the mass function of black holes in the solar-mass range predicted either by conventional stellar evolution or early Universe PBH production. We propose that analysis of the solar-mass BH population mass distribution in a narrow mass window of $\sim 1-2.5{\mathrm{M}}_{\odot }$ can provide a simple yet powerful test of the origin of these BHs. Recent LIGO/VIRGO gravitational wave (GW) observations of the binary merger events GW190425 and GW190814 are consistent with a BH mass in the range $\sim 1.5-2.6M_{\odot }$. Though these results have fueled speculation on dark matter-transmuted solar-mass BHs, we demonstrate that it is unlikely that the origin of these particular events stems from NS implosions. Data from upcoming GW observations will be able to distinguish between solar-mass BHs and NSs with high confidence. This capability will facilitate and enhance the efficacy of our proposed test.

    ↳ astro-ph.HEastro-ph.COhep-phPRL(2021)·73 citations
33. 33*

    Milky Way Accelerometry via Millisecond Pulsar Timing

    David F. Phillips🇺🇸 · Aakash Ravi🇺🇸 · Reza Ebadi🇺🇸 · Ronald L. Walsworth🇺🇸

    The temporal stability of millisecond pulsars is remarkable, rivaling even some terrestrial atomic clocks at long timescales. Using this property, we show that millisecond pulsars distributed in the galactic neighborhood form an ensemble of accelerometers from which we can directly extract the local galactic acceleration. From pulsar spin period measurements, we demonstrate acceleration sensitivity with about 1$\sigma$ precision using 117 pulsars. We also present results from a complementary analysis using orbital periods of 13 binary pulsar systems that eliminates systematics associated with pulsar braking. This work is a first step toward dynamically measuring acceleration gradients that will eventually inform us about the dark matter density distribution in the Milky Way galaxy.

    ↳ astro-ph.GAastro-ph.COastro-ph.HEhep-phPRL(2021)·28 citations
34. 34*

    A New Approach to Generalised Uncertainty Relations

    Matthew J. Lake🇨🇳

    We outline a new model in which generalised uncertainty relations are obtained without modified commutation relations. While existing models introduce modified phase space volumes for the canonical degrees of freedom, we introduce new degrees of freedom for the background geometry. The phase space is therefore enlarged but remains Euclidean. The spatial background is treated as a genuinely quantum object, with an associated state vector, and the model naturally gives rise to the extended generalised uncertainty principle (EGUP). Importantly, this approach solves (or rather, evades) well known problems associated with modified commutators, including violation of the equivalence principle, the `soccer ball' problem for multiparticle states, and the velocity dependence of the minimum length. However, it implies two radical conclusions. The first is that space must be quantised on a different scale to matter and the second is that the fundamental quanta of geometry are fermions. We explain how, in the context of the model, these do not contradict established results including the no go theorems for multiple quantisation constants, which still hold for species of material particles, and the spin-$2$ nature of gravitons.

    ↳ gr-qchep-phquant-ph25 citations
35. 35*

    Searching for new physics using optically levitated sensors

    David C. Moore🇺🇸 · Andrew A. Geraci🇺🇸

    We describe a variety of searches for new physics beyond the Standard Model of particle physics which may be enabled in the coming years by the use of optically levitated masses in high vacuum. Such systems are expected to reach force and acceleration sensitivities approaching (and possibly eventually exceeding) the standard quantum limit over the next decade. For new forces or phenomena that couple to mass, high precision sensing using objects with masses in the fg-ng range have significant discovery potential for new physics. Such applications include tests of fundamental force laws, searches for non-neutrality of matter, high-frequency gravitational wave detectors, dark matter searches, and tests of quantum foundations using massive objects.

    ↳ quant-phhep-exhep-phphysics.ins-det+1Quantum Sci.Technol.(2021)·139 citations
36. 36*

    Advances in modeling nuclear matrix elements of neutrinoless double beta decay

    J. M. Yao🇺🇸

    Accurate nuclear matrix elements (NMEs) for neutrinoless double beta decays of candidate nuclei are important for the design and interpretation of future experiments. Significant progress has been made in the modeling of these NMEs from first principles. The NME for 48Ca shows a good agreement among three different ab initio calculations starting from the same nuclear interaction constructed within the chiral EFT and the same decay operator. These studies open the door to ab initio calculations of the matrix elements for the decay of heavier nuclei such as 76Ge, 130Te, and 136Xe. The ultimate goal is the computation of NMEs in many-body calculations with controllable approximations, using nuclear interactions and weak transition operators derived consistently from chiral EFT. We are expecting more progress towards this goal in the near future.

    ↳ nucl-thhep-exhep-phnucl-exSci.Bull.(2021)·6 citations
37. 37*

    Note on Shape Moduli Stabilization, String Gas Cosmology and the Swampland Criteria

    Gabrielle A. Mitchell🇨🇦 · Robert Brandenberger (McGill University)🇨🇦

    In String Gas Cosmology, the simplest shape modulus fields are naturally stabilized by taking into account the presence of string winding and momentum modes. We determine the resulting effective potential for these fields and show that it obeys the de Sitter conjecture, one of the swampland criteria for effective field theories to be consistent with superstring theory.

    ↳ hep-thastro-ph.COgr-qchep-phEPJC(2021)·5 citations
38. 38*

    Search for a doubly-charged $DDK$ bound state in ${\rm Y}(1S,2S)$ inclusive decays and via direct production in $e^{+}{e}^{-}$ collisions at $\sqrt{s}$ = 10.520, 10.580, and 10.867 GeV

    Belle Collaboration: Y. Li🇺🇸 · S. Jia🇨🇳 · C. P. Shen🇨🇳 · I. Adachi🇯🇵 · H. Aihara🇯🇵 · S. Al Said🇸🇦 · D. M. Asner🇺🇸 · T. Aushev🇷🇺 · R. Ayad🇸🇦 · V. Babu🇩🇪 · S. Bahinipati🇮🇳 · P. Behera🇮🇳 and 195 other authors

    We report the results of a first search for a doubly-charged $DDK$ bound state, denoted the $R^{++}$, in ${\rm Y}(1S)$ and ${\rm Y}(2S)$ inclusive decays and via direct production in $e^{+}{e}^{-}$ collisions at $\sqrt{s}$ = 10.520, 10.580, and 10.867 GeV. The search uses data accumulated with the Belle detector at the KEKB asymmetric-energy $e^{+}{e}^{-}$ collider. No significant signals are observed in the $D^{+}{D}_s^{\ast +}$ invariant-mass spectra of all studied modes. The 90\% credibility level upper limits on their product branching fractions in ${\rm Y}(1S)$ and ${\rm Y}(2S)$ inclusive decays ($\mathcal{B}({\rm Y}(1S,2S)\to R^{++}+anything)\times \mathcal{B}(R^{++}\to D^{+}{D}_s^{\ast +})$), and the product values of Born cross section and branching fraction in $e^{+}{e}^{-}$ collisions ($\sigma (e^{+}{e}^{-}\to R^{++}+anything)\times \mathcal{B}(R^{++}\to D^{+}{D}_s^{\ast +})$) at $\sqrt{s}$ = 10.520, 10.580, and 10.867 GeV under different assumptions of $R^{++}$ masses varying from 4.13 to 4.17 GeV/$c^2$, and widths varying from 0 to 5 MeV are obtained.

    ↳ hep-exhep-phPRD(2020)·13 citations
39. 39*

    Instability of compact stars with a nonminimal scalar-derivative coupling

    Ryotaro Kase🇯🇵 · Shinji Tsujikawa🇯🇵

    For a theory in which a scalar field $\varphi$ has a nonminimal derivative coupling to the Einstein tensor $G_{\mu \nu }$ of the form $\varphi G_{\mu \nu }{\nabla }^{\mu }{\nabla }^{\nu }\varphi$, it is known that there exists a branch of static and spherically-symmetric relativistic stars endowed with a scalar hair in their interiors. We study the stability of such hairy solutions with a radial field dependence $\varphi (r)$ against odd- and even-parity perturbations. We show that, for the star compactness $\mathcal{C}$ smaller than $1/3$, they are prone to Laplacian instabilities of the even-parity perturbation associated with the scalar-field propagation along an angular direction. Even for $\mathcal{C}>1/3$, the hairy star solutions are subject to ghost instabilities. We also find that even the other branch with a vanishing background field derivative is unstable for a positive perfect-fluid pressure, due to nonstandard propagation of the field perturbation $\delta \varphi$ inside the star. Thus, there are no stable star configurations in derivative coupling theory without a standard kinetic term, including both relativistic and nonrelativistic compact objects.

    ↳ gr-qchep-phhep-thJCAP(2021)·11 citations
40. 40*

    Multi-field dark energy: cosmic acceleration on a steep potential

    Yashar Akrami🇫🇷 · Misao Sasaki🇯🇵 · Adam R. Solomon🇺🇸 · Valeri Vardanyan🇯🇵

    We argue that dark energy with multiple fields is theoretically well-motivated and predicts distinct observational signatures, in particular when cosmic acceleration takes place along a trajectory that is highly non-geodesic in field space. Such models provide novel physics compared to $\Lambda$CDM and quintessence by allowing cosmic acceleration on steep potentials. From the theoretical point of view, these theories can easily satisfy the conjectured swampland constraints and may in certain cases be technically natural, potential problems which are endemic to standard single-field dark energy. Observationally, we argue that while such multi-field models are likely to be largely indistinguishable from the concordance cosmology at the background level, dark energy perturbations can cluster, leading to an enhanced growth of large-scale structure that may be testable as early as the next generation of cosmological surveys.

    ↳ astro-ph.COgr-qchep-phhep-thPLB(2021)·62 citations
41. 41*

    Testing the ALP-photon coupling with polarization measurements of Sagittarius A*

    Guan-Wen Yuan🇨🇳 · Ziqing Xia🇨🇳 · Chengfeng Tang🇨🇳 · Yaqi Zhao🇨🇳 · Yi-Fu Cai🇨🇳 · Yifan Chen🇨🇳 · Jing Shu🇨🇳 · Qiang Yuan🇨🇳

    Ultra-light bosons such as axions or axion-like particles (ALPs), are promising candidates to solve the dark matter problem. A unique way to detect such ALPs is to search for the periodic oscillation feature of the position angles of linearly polarized photons emitted from the regions where ALP dark matter forms a solitonic core. In this work, we use the high-resolution polarimetric measurements of the radiation near the super-massive black hole (SMBH) in the center of the Milky Way, i.e., Sagittarius A${}^{\star }$ (Sgr A${}^{\star }$), by a sub-array of the Event Horizon Telescope to search for the ultra-light ALPs. We derive upper limits on the ALP-photon coupling of $\sim 10^{-12}\mathrm{Ge}{\mathrm{V}}^{-1}$ for ALP masses of $m\sim (10^{-19}-10^{-18})$eV. Our results are stronger than that derived from the observations of SN1987A and a population of supernovae in the mass window of ($10^{-19}-10^{-17}$)eV. Improved polarimetric measurements with the full Event Horizon Telescope can further strengthen the constraints.

    ↳ astro-ph.HEhep-phJCAP(2021)·52 citations
42. 42*

    Monochromatization of $e^{+}{e}^{-}$ colliders with a large crossing angle

    V.I. Telnov (Institute of Nuclear Physics and Novosibirsk State Univ., Novosibirsk, Russia)🇷🇺

    The relative center-of-mass energy spread at $e^{+}{e}^{-}$ colliders is about $10^{-3}$, which is much larger than the widths of narrow resonances J/$\psi$, $\psi$(2S), ${\rm Y}$(1S), ${\rm Y}$(2S), ${\rm Y}$(3S) mesons, tauonium and some others. It's reduction would significantly increase the resonance production rates and open up great opportunities in the search for new physics. In this paper, we propose a new monochromatization method for colliders with a large crossing angle (which can provide a high luminosity). The contribution of the beam energy spread to the spread of the center-of-mass energy is canceled by introducing an appropriate energy-angle correlation at the interaction point; ${\sigma }_W/W\sim (0.5-1)10^{-5}$ appears possible.

    ↳ physics.acc-phhep-exhep-phMod.Phys.Lett.A(2024)·20 citations
43. 43*

    Radio impulsive events in quiet solar corona and Axion Quark Nugget Dark Matter

    Shuailiang Ge🇨🇦 · Md Shahriar Rahim Siddiqui🇨🇦 · Ludovic Van Waerbeke🇨🇦 · Ariel Zhitnitsky🇨🇦

    The Murchison Widefield Array (MWA) recorded \cite{Mondal-2020} impulsive radio events in the quiet solar corona at frequencies 98, 120, 132, and 160 MHz. We propose that these radio events are the direct manifestation of dark matter annihilation events within the axion quark nugget (AQN) framework. It has been argued \cite{Zhitnitsky:2017rop,Raza:2018gpb} that the AQN annihilation events in the quiet solar corona can be identified with the nanoflares conjectured by Parker \cite{Parker-1983}. We further support this claim by demonstrating that observed impulsive radio events \cite{Mondal-2020}, including their rate of appearance, their temporal and spatial distributions and their energetics, are matching the generic consequences of AQN annihilations in the quiet corona. We propose to test this idea by analyzing the correlated clustering of impulsive radio events in different frequency bands. These correlations are expressed in terms of the time delays between radio events in different frequency bands, measured in seconds. We also make generic predictions for low (80 and 89 MHz) and high (179, 196, 217 and 240 MHz) frequency bands, that have been recorded, but not published, by \cite{Mondal-2020}. We finally suggest to test our proposal by studying possible cross-correlation between MWA radio signals and Solar Orbiter recording of extreme UV photons (a.k.a. "campfires").

    ↳ astro-ph.HEastro-ph.IMastro-ph.SRhep-phPRD(2020)·16 citations
44. 44*

    New Early Dark Energy is compatible with current LSS data

    Florian Niedermann🇩🇰 · Martin S. Sloth🇩🇰

    Recently a full-shape analysis of large-scale structure (LSS) data was employed to provide new constraints on a class of Early Dark Energy (EDE) models. In this note, we derive similar constraints on New Early Dark Energy (NEDE) using the publicly available PyBird code, which makes use of the effective field theory of LSS. We study the NEDE base model with the fraction of NEDE and the trigger field mass as two additional parameters allowed to vary freely while making simplifying assumptions about the decaying fluid sector. Including the full-shape analysis of LSS together with measurements of the cosmic microwave background (CMB), baryonic acoustic oscillations (BAO) and supernovae (SN) data, we report $H_0=71.2\pm 1.0\text{km}{\text{s}}^{-1}{\text{Mpc}}^{-1}$ ($68\%$ C.L.) together with a $\simeq 4\sigma$ evidence for a non-vanishing fraction of NEDE. This is an insignificant change to the value previously found without full-shape LSS data, $H_0=71.4\pm 1.0\text{km}{\text{s}}^{-1}{\text{Mpc}}^{-1}$ ($68\%$ C.L.). As a result, while the NEDE fit cannot be improved upon the inclusion of additional LSS data, it is also not adversely affected by it, making it compatible with current constraints from LSS data. In fact, we find evidence that the effective field theory of LSS acts in favor of NEDE.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2021)·89 citations
45. 45*

    Double Copy in Higher Derivative Operators of Nambu-Goldstone Bosons

    Ian Low🇺🇸 · Laurentiu Rodina🇫🇷 · Zhewei Yin🇺🇸

    We investigate the existence of double copy structure, or the lack thereof, in higher derivative operators for Nambu-Goldstone bosons. At the leading $\mathcal{O}(p^2)$, tree amplitudes of Nambu-Goldstone bosons in the adjoint representation can be (trivially) expressed as the double copy of itself and the cubic bi-adjoint scalar theory, through the Kawai-Lewellen-Tye bilinear kernel. At the next-to-leading $\mathcal{O}(p^4)$ there exist four operators in general, among which we identify one operator whose amplitudes exhibit the flavor-kinematics duality and can be written as the double copy of $\mathcal{O}(p^2)$ Nambu-Goldstone amplitudes and the Yang-Mills+${\varphi }^3$ theory, involving both gluons and gauged cubic bi-adjoint scalars. The specific operator turns out to coincide with the scalar $\mathcal{O}(p^4)$ operator in the so-called extended Dirac-Born-Infeld theory, for which the aforementioned double copy relation holds more generally.

    ↳ hep-thhep-phPRD(2021)·33 citations
46. 46*

    The response of ultralight dark matter to supermassive black holes and binaries

    Lorenzo Annulli🇵🇹 · Vitor Cardoso🇵🇹 · Rodrigo Vicente🇵🇹

    Scalar fields can give rise to confined structures, such as boson stars or Q-balls. These objects are interesting hypothetical new "dark matter stars," but also good descriptions of dark matter haloes when the fields are ultralight. Here, we study the dynamical response of such confined bosonic structures when excited by external matter (stars, planets or black holes) in their vicinities. Such perturbers can either be plunging through the bosonic configuration or simply act as periodic sources. Our setup can also efficiently describe the interaction between a massive black hole and the surrounding environment, shortly after the massive body has undergone a "kick", due to the collapse of baryonic matter at the galactic center. It also depicts dark matter depletion as a reaction to an inspiralling binary within the halo. We calculate total energy loss, and linear and angular momenta radiated during these processes, and perform the first self-consistent calculation of dynamical friction acting on moving bodies in these backgrounds. We show that the gravitational collapse to a supermassive black hole at the center of a Newtonian boson star (NBS) is accompanied by a small change in the surrounding core. The NBS eventually gets accreted, but only on times larger than a Hubble scale for astrophysical parameters. Stellar or supermassive binaries are able to "stir" and expel scalar from the NBS. For binaries in the LIGO or LISA band, close to coalescence, scalar emission affects the waveform at leading $-6$ PN order with respect to the dominant quadrupolar term; the coefficient is too small to allow detection by next-generation interferometers. Our results provide a complete picture of the interaction between black holes or stars and the ultralight dark matter environment they live in.

    ↳ gr-qcastro-ph.HEhep-phhep-thPRD(2020)·126 citations
47. 47*

    Quantitative Analysis of the Stochastic Approach to Quantum Tunneling

    Mark P. Hertzberg🇺🇸 · Fabrizio Rompineve🇺🇸 · Neil Shah🇺🇸

    Recently there has been increasing interest in alternate methods to compute quantum tunneling in field theory. Of particular interest is a stochastic approach which involves (i) sampling from the free theory Gaussian approximation to the Wigner distribution in order to obtain stochastic initial conditions for the field and momentum conjugate, then (ii) evolving under the classical field equations of motion, which leads to random bubble formation. Previous work showed parametric agreement between the logarithm of the tunneling rate in this stochastic approach and the usual instanton approximation. However, recent work [1] claimed excellent agreement between these methods. Here we show that this approach does not in fact match precisely; the stochastic method tends to overpredict the instanton tunneling rate. To quantify this, we parameterize the standard deviations in the initial stochastic fluctuations by $ϵ\sigma$, where $\sigma$ is the actual standard deviation of the Gaussian distribution and $ϵ$ is a fudge factor; $ϵ=1$ is the physical value. We numerically implement the stochastic approach to obtain the bubble formation rate for a range of potentials in 1+1-dimensions, finding that $ϵ$ always needs to be somewhat smaller than unity to suppress the otherwise much larger stochastic rates towards the instanton rates; for example, in the potential of [1] one needs $ϵ\approx 1/2$. We find that a mismatch in predictions also occurs when sampling from other Wigner distributions, and in single particle quantum mechanics even when the initial quantum system is prepared in an exact Gaussian state. If the goal is to obtain agreement between the two methods, our results show that the stochastic approach would be useful if a prescription to specify optimal fudge factors for fluctuations can be developed.

    ↳ hep-thastro-ph.COgr-qchep-ph+1PRD(2020)·28 citations
48. 48*

    Harnessing the Population Statistics of Subhalos to Search for Annihilating Dark Matter

    Jean J. Somalwar🇺🇸 · Laura J. Chang🇺🇸 · Siddharth Mishra-Sharma🇺🇸 · Mariangela Lisanti🇺🇸

    The Milky Way's dark matter halo is expected to host numerous low-mass subhalos with no detectable associated stellar component. Such subhalos are invisible unless their dark matter annihilates to visible states such as photons. One of the established methods for identifying candidate subhalos is to search for individual unassociated gamma-ray sources with properties consistent with the dark matter expectation. However, robustly ruling out an astrophysical origin for any such candidate is challenging. In this work, we present a complementary approach that harnesses information about the entire population of subhalos---such as their spatial and mass distribution in the Galaxy---to search for a signal of annihilating dark matter. Using simulated data, we show that the collective emission from subhalos can imprint itself in a unique way on the statistics of observed photons, even when individual subhalos may be too dim to be resolved on their own. Additionally, we demonstrate that, for the models we consider, the signal can be identified even in the face of unresolved astrophysical point-source emission of extragalactic and Galactic origin. This establishes a new search technique for subhalos that is complementary to established methods, and that could have important ramifications for gamma-ray dark matter searches using observatories such as the Fermi Large Area Telescope and the Cherenkov Telescope Array.

    ↳ astro-ph.COastro-ph.HEhep-phApJ(2021)·12 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.