Tue·Mar 17, 2020Tuesday·March 17, 2020

1. 01*

   Dead or Alive? Implications of the Muon Anomalous Magnetic Moment for 3-3-1 Models

   Alvaro S. de Jesus🇧🇷 · Sergey Kovalenko🇨🇱 · Farinaldo S. Queiroz🇧🇷 · Carlos A. de S. Pires🇧🇷 · Yoxara S. Villamizar🇧🇷

   We have witnessed a persistent puzzling anomaly in the muon magnetic moment that cannot be accounted for in the Standard Model even considering the large hadronic uncertainties. A new measurement is forthcoming, and it might give rise to a $5\sigma$ claim for physics beyond the Standard Model. Motivated by it, we explore the implications of this new result to five models based on the $SU(3{)}_C\times SU(3{)}_L\times U(1{)}_N$ gauge symmetry and put our conclusions into perspective with LHC bounds. We show that previous conclusions found in the context of such models change if there are more than one heavy particle running in the loop. Moreover, having in mind the projected precision aimed by the g-2 experiment at FERMILAB, we place lower mass bounds on the particles that contribute to muon anomalous magnetic moment assuming the anomaly is resolved otherwise. Lastly, we discuss how these models could accommodate such anomaly in agreement with existing bounds.

   hep-phPLB(2020)·28 citations
2. 02*

   Neutrino phenomenology in a left-right $D_4$ symmetric model

   Cesar Bonilla🇨🇱 · Leon M.G. de la Vega🇲🇽 · R. Ferro-Hernandez🇲🇽 · Newton Nath🇲🇽 · Eduardo Peinado🇲🇽

   We present a minimal left-right symmetric flavor model and analyze the predictions for the neutrino sector. In this scenario, the Yukawa sector is shaped by the dihedral $D_4$ symmetry which leads to correlations for the neutrino mixing parameters. We end up with four possible solutions within this model. We further analyzed the impact of the upcoming long-baseline neutrino oscillation experiment DUNE. Due to its high sensitivity, DUNE will be able to rule out two of the solutions. Finally, the prediction for the neutrinoless double beta decay for the model has also been examined.

   hep-phPRD(2020)·10 citations
3. 03*

   Relaxation time for the alignment between the spin of a finite-mass quark/antiquark and the thermal vorticity in relativistic heavy-ion collisions

   Alejandro Ayala🇲🇽 · David de la Cruz🇲🇽 · L. A. Hernández🇲🇽 · Jordi Salinas🇲🇽

   We study the relaxation time required for the alignment between the spin of a finite-mass quark/antiquark and the thermal vorticity, at finite temperature and baryon chemical potential, in the context of relativistic heavy-ion collisions. The relaxation time is computed as the inverse of the total reaction rate that in turn is obtained from the imaginary part of the quark/antiquark self-energy. We model the interaction between spin and thermal vorticity within the medium by means of a vertex coupling quarks and thermal gluons that, for a uniform temperature, is proportional to the global angular velocity and inversely proportional to the temperature. We use realistic estimates for the angular velocities for different collision energies and show that the effect of the quark mass is to reduce the relaxation times as compared to the massless quark case. Using these relaxation times we estimate the intrinsic quark and antiquark polarizations produced by the thermal vorticity. We conclude by pointing out that, in spite of the former being larger than the latter, it is still possible to understand recent results from the STAR Beam Energy Scan when accounting for the fact that only a portion of quarks/antiquarks come from the denser and thus thermalized region in the collision.

   hep-phnucl-thPRD(2020)·36 citations
4. 04*

   Scalar clockwork and flavor neutrino mass matrix

   Teruyuki Kitabayashi🇯🇵

   We study the capability of generating correct flavor neutrino mass matrix in a scalar clockwork model. First, we assume that the flavor structure is controlled by the Yukawa couplings as same as the standard model. In this case, the correct flavor neutrino mass matrix could be obtained by appropriate Yukawa couplings $Y_{{\ell }^{\prime }\ell }$ where ${\ell }^{\prime },\ell =e,\mu ,\tau$. Next, we assume that the Yukawa couplings are extremely democratic $|Y_{{\ell }^{\prime }\ell }|=1$. In this case, the model parameters of the scalar clockwork sector, such as the site number of a clockwork gear in a clockwork chain, should have the flavor indices ${\ell }^{\prime }$ and/or $\ell$ to generate correct flavor neutrino mass matrix. We show some examples of the assignments of the flavor indices which can yield the correct flavor neutrino mass matrix.

   hep-phPTEP(2020)·4 citations
5. 05*

   Deuteron polarizations in the proton-deuteron Drell-Yan process for finding the gluon transversity

   S. Kumano🇯🇵 · Qin-Tao Song🇨🇳

   The gluon transversity distribution in the deuteron is defined by the matrix element between linearly-polarized deuteron states, and it could be investigated in proton-deuteron collisions in addition to lepton-deuteron scattering. The linear polarization of photon is often used, whereas it is rarely used for the spin-1 deuteron. Therefore, it is desirable to express deuteron-reaction cross sections in term of conventional deuteron spin polarizations for actual experimental measurements. In this work, we investigate how proton-deuteron Drell-Yan cross sections are expressed by the conventional polarizations for finding the gluon transversity distribution. In particular, we show that the gluon transversity can be measured in the proton-deuteron Drell-Yan process by taking the cross-section difference between the deuteron spin polarizations along the two-transverse axes. Since the gluon transversity does not exist for the spin-1/2 nucleons, a finite gluon transversity of the deuteron could indicate an "exotic" mechanism beyond the simple bound system of the nucleons in the deuteron. Therefore, the gluon transversity is an interesting and appropriate observable to shed light on a new hadronic mechanism in nuclei.

   hep-phhep-exhep-latnucl-thPRD(2020)·19 citations
6. 06*

   Muon and electron $g-2$ and lepton masses in flavor models

   Lorenzo Calibbi🇨🇳 · M.L. López-Ibáñez🇨🇳 · Aurora Melis🇪🇸 · Oscar Vives🇪🇸

   The stringent experimental bound on $\mu \to e\gamma$ is compatible with a simultaneous and sizable new physics contribution to the electron and muon anomalous magnetic moments $(g-2{)}_{\ell }$ ($\ell =e,\mu$), only if we assume a non-trivial flavor structure of the dipole operator coefficients. We propose a mechanism in which the realization of the $(g-2{)}_{\ell }$ correction is manifestly related to the mass generation through a flavor symmetry. A radiative flavon correction to the fermion mass gives a contribution to the anomalous magnetic moment. In this framework, we introduce a chiral enhancement from a non-trivial $\mathcal{O}(1)$ quartic coupling of the scalar potential. We show that the muon and electron anomalies can be simultaneously explained in a vast region of the parameter space with predicted vector-like mediators of masses as large as $M_{\chi }\in [0.6,2.5]$~TeV.

   hep-phJHEP(2020)·69 citations
7. 07*

   Sensitivity physics expected to the measurement of the quartic $WW\gamma \gamma$ couplings at the LHeC and the FCC-he

   E. Gurkanli🇹🇷 · V. Ari🇹🇷 · A. Gutiérrez-Rodríguez🇲🇽 · M. A. Hernández-Ruíz🇲🇽 · M.Koksal🇹🇷

   We explore the physics expected sensitivity at the Large Hadron electron Collider (LHeC) and the Future Circular Collider-hadron electron (FCC-he) to search for the anomalous quartic $WW\gamma \gamma$ couplings in single $W$-boson production in association with a photon. We study the process $ep\to e^{-}{\gamma }^{\ast }p\to eW\gamma q^{\prime }X$ via the subprocess ${\gamma }^{\ast }q\to W\gamma q^{\prime }$. The center-of-mass energies and luminosities of the LHeC are assumed to be $\sqrt{s}=1.30,1.98$ TeV, $\mathcal{L}=10-100$ $\mathrm{f}{\mathrm{b}}^{-1}$ and for the FCC-he $\sqrt{s}=3.46,5.29$ TeV and $\mathcal{L}=100-1000$ $\mathrm{f}{\mathrm{b}}^{-1}$. With these energies and luminosities, we estimate bounds on the anomalous quartic $WW\gamma \gamma$ couplings at $95\%$ C.L., which can be an order of magnitude stringent than the experimental limits report by ATLAS and CMS Collaborations at the LHC.

   hep-phJ.Phys.G(2020)·9 citations
8. 08*

   Dark-matter-spin effects at future $e^{+}{e}^{-}$ colliders

   Bohdan Grzadkowski🇵🇱 · Michal Iglicki🇵🇱 · Krzysztof Mekala🇵🇱 · Aleksander Filip Zarnecki🇵🇱

   We discuss possibility to detect spin 0, 1 and 1/2 dark matter (DM) at future $e^{+}{e}^{-}$ colliders. The models considered here are simple, consistent and renormalizable field theories, that provide correct DM abundance and satisfy direct detection, indirect detection and collider constraints. The intention of this paper was to verify to what extend it might be possible to disentangle models of different DM spins by measurement of the cross section for $e^{+}{e}^{-}\to Z+\dots$ at future $e^{+}{e}^{-}$ colliders. We specialize to the case of the ILC operating at $\sqrt{s}=250\text{GeV}$, however our results apply as well for the FCC-ee and the CEPC colliders. For each model the cross section maximized with respect to parameters was calculated and compared to the expected 95% CL cross-section limits estimated for the ILC. It turned out that near $2m_{\text{DM}}\simeq m_{1,2}$ resonances, where $m_1$ and $m_2$ are the SM Higgs boson and a non-standard Higgs boson masses, respectively, there exist substantial regions where the models are testable. A special attention has been payed to calculation of the cross section in the region where $m_1\simeq m_2$.

   hep-phJHEP(2020)·13 citations
9. 09*

   Identify the hidden charm pentaquark signal from non-resonant background in electron-proton scattering

   Zhi Yang🇨🇳 · Xu Cao🇨🇳 · Yu-Tie Liang🇨🇳 · Jia-Jun Wu🇨🇳

   We study the electroproduction of the LHCb pentaquark states with the assumption that they are resonant states. The main concern here is to investigate the final state distribution in the phase space in order to extract the feeble pentaquark signal from the large non-resonant background. Our results show that the ratio of the signal to background would increase significantly with proper kinematic cut, which would be very helpful for future experimental analysis.

   hep-phhep-exnucl-thCPC(2020)·14 citations
10. 10*

    Boosting Invisible Higgs Searches by Tagging a Gluon Jet for Gluon Fusion Process

    Won Sang Cho🇰🇷 · Hyung Do Kim🇰🇷 · Dongsub Lee (Seoul National University)🇰🇷

    We propose a novel method in that quark-gluon tagging of the jets emitted as initial state radiation (ISR) can boost searches of invisible Higgs from gluon fusion processes against irreducible electroweak vector boson productions. While quark ISR typically takes up a dominant portion than gluon in the background processes mainly by frequent quark-gluon initiated hard scatterings at the LHC, gluon ISR portion in the gluon fusion can be significantly larger in the central region of detector. Focusing on invisible Higgs searches using jet substructure variables capturing the new features, we demonstrate that Higgs from gluon fusion constrains invisible Higgs decays the most, over vector boson fusion traditionally known as the most constraining, and the limit on the branching ratio is significantly improved. We summarize with emphasizing that our method has wider implications in search for new resonances from gluon fusion processes.

    hep-phhep-exPRD(2020)·4 citations
11. 11*

    Non-Extensive Behaviour of the QCD Strong Coupling Constant

    K. Javidan🇮🇷 · M. M. Yazdanpanah🇮🇷 · H. Nematollahi🇮🇷

    The compatibility of theoretically calculated values for the strong coupling constant,through the renormalization group approach with experimental data is studied. There exist considerable divergence in-between theoretical and experimental results at low energies, which can not be explained by thermal field theory and considering chemical potential. Such great deviation can be treated successfully by considering the q-generalized statistical effects through adding a q-nonextensive parameter in the fitting of theoretical results on experimental data.

    hep-phnucl-thEPJA(2021)·7 citations
12. 12*

    Consequences of Neutrinoless Double Decays Dominated by Short Range Interactions

    C.Q. Geng🇨🇳 · J.N. Ng🇨🇦

    We investigate some consequences if neutrinoless double beta decays of nuclei are dominated by short range interactions. To illustrate our results, we assume that such decays proceed mainly through short range interactions involving two-W-bosons exchanges and confine ourselves to only include new scalars without new gauge interactions for SM fermions. For the neutrino mass problem we propose to solve it by adopting that the active light neutrinos have predominantly Dirac masses and the small Majorana masses induced by the new scalars render them pseudo(quasi)-Dirac particles. This particular aspect of neutrinos may be detectable in the next generation of neutrino oscillation experiments and/or neutrino telescopes. If so this opens a new connection between neutrinoless double beta decays and neutrino physics. We also noted the new physics signals such as high charged scalar states that can be explored in hadron colliders. In particular, we find that a high energy e^- e^- collider will be very useful in testing the origin of lepton number violation which complements neutrinoless double decays studies.

    hep-phPRD(2020)·2 citations
13. 13*

    Non-zero tensor condensates in cold quark matter within the three-flavor Nambu-Jona-Lasinio model with the Kobayashi-Maskawa-'t Hooft interaction

    A. Kagawa (Kochi Univ., Japan)🇯🇵 · M. Morimoto (Kochi Univ., Japan)🇯🇵 · Y. Tsue (Kochi Univ., Japan)🇯🇵 · J. da Providencia (Univ. de Coimbra, Portugal)🇵🇹 · C. Providencia (Univ. de Coimbra, Portugal)🇵🇹 · M. Yamamura (Kansai Univ., Japan)🇯🇵

    The possible formation of tensor condensates originated from a tensor-type interaction between quarks is investigated in the three-flavor Nambu-Jona-Lasinio model including the Kobayashi-Maskawa-'t Hooft interaction, which leads to flavor mixing. It is shown that independent two tensor condensates appear and a tensor condensate related to the strange quark easily occurs by the effect of the flavor mixing compared with one related to light quarks. Also, it is shown that the tensor condensate related to the strange quark appears at a slightly smaller chemical potential if the Kobayashi-Maskawa-'t Hooft interaction is included, due to the flavor mixing effect. It is also shown that the two kinds of tensor condensates may coexist in a certain quark chemical potential due to the flavor mixing.

    hep-phnucl-thIJMPE(2020)·2 citations
14. 14*

    Charged Higgs Contribution on B_c decays into (D_s,D_s^*)l^+ l^-

    P. Maji🇮🇳 · S. Biswas🇮🇳 · P. Nayek🇮🇳 · S. Sahoo🇮🇳

    In this paper, we study rare semileptonic decays of B_c meson in the context of type-I, II, and III two Higgs doublet model. We follow the relativistic quark model for parameterizing the form factors used in matrix elements of weak transitions between the corresponding meson states. We investigate the observables such as branching ratio, lepton polarization asymmetry, forward-backward asymmetry, etc. and analyze the dependence of these quantities on the model parameters. We have found that there are noticeable sensitivity of these observables for charged Higgs boson, which may provide a powerful probe to the standard model and new physics beyond it.

    hep-phPTEP(2020)·6 citations
15. 15*

    Evidences for a pseudo scalar resonance at 400 GeV Possible interpretations

    Francois Richard🇫🇷

    This paper intends to collect the various evidences observed by ATLAS and CMS within searches for heavy scalars and pseudocalars. These searches in tt, hZ, tautau and 2jets+W, obtain individual excesses in five channels, each at a modest level of significance, ~3 standard deviations, but, put together, give a strong evidence for a pseudoscalar at ~400 GeV. Preliminary interpretations are given which suggest that additional observations should appear in the HL-LHC phase.

    hep-phhep-ex12 citations
16. 16*

    Revisiting the determining fraction of glueball component in $f_0$ mesons via radiative decays of $J/\psi$

    Xing-Dao Guo🇨🇳 · Hong-Wei Ke🇨🇳 · Ming-Gang Zhao🇨🇳 · Liang Tang🇨🇳 · Xue-Qian Li🇨🇳

    QCD theory predicts the existence of glueballs, but so far all experimental endeavors have failed to identify any such states. To remedy this discrepancy between QCD, which has proven to be a successful theory for strong interactions, and the failure of experimental searches for glueballs, one is tempted to accept the promising interpretation that the glueballs mix with regular $q\bar{q}$ states of the same quantum numbers. The lattice estimate of the masses of pure $0^{++}$ glueballs ranges from 1 to 2 GeV, which is the region of the $f_0$ family. Thus many authors suggest that the $f_0$ mesonic series is an ideal place to study possible mixtures of glueballs and $q\bar{q}$. In this paper, following the strategy proposed by Close, Farrar and Li, we try to determine the fraction of glueball components in $f_0$ mesons using the measured mass spectra and the branching ratios of $J/\psi$ radiative decays into $f_0$ mesons. Since the pioneering papers by Close et al., more than 20 years has elapsed and more accurate measurements have been done by several experimental collaborations, so it is time to revisit this interesting topic using new data. We suppose $f_0(500)$ and $f_0(980)$ to be pure quark states, while for $f_0(1370)$, $f_0(1500)$ and $f_0(1710)$, to fit both the experimental data of $J/\psi$ radiative decay and their mass spectra, glueball components are needed. Moreover, the mass of the pure $0^{++}$ glueball is phenomenologically determined.

    hep-phCPC(2021)·15 citations
17. 17*

    Role of the low-lying nucleon resonances in the $p\bar{p}\to \psi \eta$ reaction

    Qin-Song Zhou🇨🇳 · Jun-Zhang Wang🇨🇳 · Ju-Jun Xie🇨🇳 · Xiang Liu🇨🇳

    Within the effective Lagrangian approach, we study the $p\bar{p}\to \psi \eta$ [$\psi \equiv \psi (3686)$, $J/\psi$] reaction at the low energy where the contributions from nucleon pole and low-lying nucleon resonances, $N(1520)$, $N(1535)$ and $N(1650)$ are considered. All the model parameters are determined with the help of current experimental data on the decay of $\psi \to p\bar{p}\eta$. Within the model parameters, the total and differential cross sections of the $p\bar{p}\to \psi \eta$ reaction are predicted. We show that the relative phases between different amplitudes of different nucleon resonance will change significantly the angular distributions of the $\bar{p}p\to \psi \eta$ reaction. Therefore, we conclude that these reactions are suitable to study experimentally the properties of the low-lying nucleon resonance and the reaction mechanisms. We hope that these theoretical calculations can be tested by future experiments.

    hep-phhep-exnucl-thPRD(2020)·1 citation
18. 18*

    The Higgs condensate as a quantum liquid

    Paolo Cea🇮🇹

    We model the Higgs condensate of the Standard Model as a relativistic quantum fluid analogous to superfluid helium. We find that the low-lying excitations of the Higgs condensate behave like two relativistic Higgs fields. The lighter Higgs boson has a mass of order $10^2$ GeV. We identify this light Higgs particle with the new LHC resonance at 125 GeV. The heavy Higgs boson has a mass around 750 GeV consistent with our recent phenomenological analysis of the preliminary LHC Run 2 data in the golden channel. We critical compare our theoretical scenario with two Higgs bosons to the available LHC Run 2 data.

    hep-phhep-exInt.J.Theor.Phys.(2020)·5 citations
19. 19*

    Search for dark sector physics with NA64

    S.N.Gninenko🇷🇺 · N.V.Krasnikov🇷🇺 · V.A.Matveev🇷🇺

    The NA64 experiment consists of two detectors which are planned to be located at the electron (NA64e) and muon (NA64$\mu$) beams of the CERN SPS and start operation after the LHC long-stop 2 in 2021. Its main goals include searches for dark sector physics - particularly light dark matter (LDM), visible and invisible decays of dark photons ($A^{\prime }$), and new light particles that could explain the ${}^8$Be and $g_{\mu }-2$ anomalies. Here we review these physics goals, the current status of NA64 including recent results and perspectives of further searches, as well as other ongoing or planned experiments in this field. The main theoretical results on LDM, the problem of the origin of the $\gamma -A^{\prime }$ mixing term and its connection to loop corrections, possible existence of a new light $Z^{\prime }$ coupled to $L_{\mu }-L_{\tau }$ current are also discussed.

    hep-phPhys.Part.Nucl.(2020)·42 citations
20. 20*

    Laplace method for the simplest diagrams of elastic scattering of scalar particles

    I.V. Sharph🇺🇦 · T.M. Zelentsova🇺🇦 · N.O. Chudak🇺🇦 · O.S. Potiienko🇺🇦 · D.A. Ptashynskiy🇺🇦 · K.K. Merkotan🇺🇦 · T.V. Yushkevich🇺🇦 · A.O. Milieva🇺🇦

    We propose an algorithm for the application of the Laplace method for the calculation of the simplest Feynman diagram with a single loop in the scalar {\phi}^3 theory. The calculation of the contribution of such a diagram to the scattering amplitude requires the calculation of a fourfold integral over the four-momenta components circulating in a loop. The essence of the Laplace method for the calculation of multiple integrals lies in the fact that if the module of an integrand has a point of sufficiently sharp maximum inside the integration domain, then the integral can be replaced by a Gaussian integral by representing the integrand in the form of an exponent from the logarithm and expanding this logarithm into Taylor series in the vicinity of a maximum point up to the second degree terms. We show that there are two-dimensional and non-intersecting surfaces inside the four-dimensional region of integration, on which the maximum of the module of integrand is reached. This leads to a problem that the integrand is non-analytically dependent on the parameters responsible for bypassing the poles. Also the derivatives of logarithm of the scattering amplitude are non-analytically dependent on these parameters. However, in the paper we show that these non-analyticities compensate each other. As a result of such a procedure, three of the four integrations can be done analytically, and the calculation of the contribution of the diagram to the scattering amplitude is reduced to a numerical calculation of the single integral in finite bounds from an expression that does not contain non-analyticities. The described calculation method is used to construct a model dependence of elastic scattering differential cross section d{\sigma}_elastic/dt on the square of the transmitted four-momentum t (Mandelstam variable).

    hep-ph1 citation
21. 21*

    Gravitational waves from first-order cosmological phase transitions: lifetime of the sound wave source

    John Ellis🇬🇧 · Marek Lewicki🇬🇧 · José Miguel No🇪🇸

    We survey systematically the general parametrisations of particle-physics models for a first-order phase transition in the early universe, including models with polynomial potentials both with and without barriers at zero temperature, and Coleman-Weinberg-like models with potentials that are classically scale-invariant. We distinguish three possibilities for the transition - detonations, deflagrations and hybrids - and consider sound waves and turbulent mechanisms for generating gravitational waves during the transitions in these models, checking in each case the requirement for successful percolation. We argue that in models without a zero-temperature barrier and in scale-invariant models the period during which sound waves generate gravitational waves lasts only for a fraction of a Hubble time after a generic first-order cosmological phase transition, whereas it may last longer in some models with a zero-temperature barrier that feature severe supercooling. We illustrate the implications of these results for future gravitational-wave experiments.

    hep-phastro-ph.COJCAP(2020)·245 citations
22. 22*

    Infrasonic, acoustic and seismic waves produced by the Axion Quark Nuggets

    Dmitry Budker🇩🇪 · Victor V. Flambaum🇦🇺 · Ariel Zhitnitsky🇨🇦

    We advocate an idea that the Axion Quark Nuggets (AQN) hitting the Earth can be detected by analysing the infrasound, acoustic and seismic waves which always accompany the AQN's passage in the atmosphere and underground. Our estimates for the infrasonic frequency $\nu \simeq 5$ ~Hz and overpressure $\delta p\sim 0.3$Pa for relatively large size dark matter (DM) nuggets suggest that sensitivity of presently available instruments is already sufficient to detect very intense (but very rare) events today with existing technology. A study of much more frequent but less intense events requires a new type of instruments. We propose a detection strategy for a systematic study to search for such relatively weak and frequent events by using Distributed Acoustic Sensing and briefly mention other possible detection methods.

    hep-phastro-ph.COastro-ph.EPphysics.ao-ph+1Symmetry(2022)·35 citations
23. 23*

    Impact of Higgs portal on gravity-mediated production of superheavy dark matter

    Marco Chianese🇳🇱 · Bowen Fu🇬🇧 · Stephen F. King🇬🇧

    In the so-called Planckian Interacting Dark Matter (PIDM) scenario, superheavy dark matter particles are produced after inflation by gravity-mediated interactions through the freeze-in mechanism. In the minimal PIDM model, the absence of any additional direct coupling with Standard Model particles is assumed. However, for scalar dark matter particles there is no symmetry that suppresses the Higgs portal coupling. In this paper, we therefore study the impact of a non-zero interaction with the Higgs field on the PIDM paradigm for scalar dark matter. In particular, we fully explore the model parameter space in order to identify the allowed regions where the correct dark matter abundance is achieved. Moreover, we provide the threshold value for the Higgs portal coupling below which the corresponding production processes are sub-dominant and the minimal PIDM scenario is preserved. For a benchmark scalar dark matter mass of $10^{15}$ GeV, we find that the Higgs portal coupling has to be smaller than $5.1\times 10^{-8}$ ($1.1\times 10^{-7}$) for instantaneous (non-instantaneous) reheating.

    hep-phJCAP(2020)·49 citations
24. 24*

    Optimizing Energetic Light Dark Matter Searches in Dark Matter and Neutrino Experiments

    Doojin Kim🇺🇸 · Pedro A. N. Machado🇺🇸 · Jong-Chul Park🇰🇷 · Seodong Shin🇺🇸

    Neutrino and dark matter experiments with large-volume ($\gtrsim 1$ ton) detectors can provide excellent sensitivity to signals induced by energetic light dark matter coming from the present universe. Taking boosted dark matter as a concrete example of energetic light dark matter, we scrutinize two representative search channels, electron scattering and proton scattering including deep inelastic scattering processes, in the context of elastic and inelastic boosted dark matter, in a completely detector-independent manner. In this work, a dark gauge boson is adopted as the particle to mediate the interactions between the Standard Model particles and boosted dark matter. We find that the signal sensitivity of the two channels highly depends on the (mass-)parameter region to probe, so search strategies and channels should be designed sensibly especially at the earlier stage of experiments. In particular, the contribution from the boosted-dark-matter-initiated deep inelastic scattering can be subleading (important) compared to the quasi-elastic proton scattering, if the mass of the mediator is below (above) $\mathcal{O}$(GeV). We demonstrate how to practically perform searches and relevant analyses, employing example detectors such as DarkSide-20k, DUNE, Hyper-Kamiokande, and DeepCore, with their respective detector specifications taken into consideration. For other potential detectors we provide a summary table, collecting relevant information, from which similar studies can be fulfilled readily.

    hep-phhep-exJHEP(2020)·34 citations
25. 25*

    Quantum Computing for Quantum Tunnelling

    Steven Abel🇬🇧 · Nicholas Chancellor🇬🇧 · Michael Spannowsky🇬🇧

    We demonstrate how quantum field theory problems can be embedded on quantum annealers. The general method we use is a discretisation of the field theory problem into a general Ising model, with the continuous field values being encoded into Ising spin chains. To illustrate the method, and as a simple proof of principle, we use a (hybrid) quantum annealer to recover the correct profile of the thin-wall tunnelling solution. This method is applicable to many nonperturbative problems.

    hep-phcond-mat.stat-mechhep-thquant-phPRD(2021)·49 citations
26. 26*

    Collision system size scan of collective flows in relativistic heavy-ion collisions

    S. Zhang🇨🇳 · Y. G. Ma🇨🇳 · G. L. Ma🇨🇳 · J. H. Chen🇨🇳 · Q. Y. Shou🇨🇳 · W. B. He🇨🇳 · C. Zhong🇨🇳

    Initial geometrical distribution and fluctuation can affect the collective expansion in relativistic heavy-ion collisions. This effect may be more evident in small system (such as B + B) than in large one (Pb + Pb). This work presents the collision system dependence of collective flows and discusses about effects on collective flows from initial fluctuations in a framework of a multiphase transport model. The results shed light on system scan on experimental efforts to small system physics.

    ↳ nucl-thhep-phnucl-exPLB(2020)·19 citations
27. 27*

    Escape from the swamp with spectator

    Kazuhiro Kogai🇯🇵 · Yuichiro Tada🇯🇵

    In the context of string theory, several conjectural conditions have been proposed for low energy effective field theories not to be in swampland, the UV-incomplete class. The recent ones represented by the de Sitter and trans-Planckian censorship conjectures in particular seem to conflict with the inflation paradigm of the early universe. We first point out that scenarios where inflation is repeated several times (multi-phase inflation) can be easily compatible with these conjectures. In other words, we relax the constraint on the single inflation for the large scale perturbations to only continue at least around 10 e-folds. In this context, we then investigate if a spectator field can be a source of the almost scale-invariant primordial perturbations on the large scale. As a consequence of such an isocurvature contribution, the resultant perturbations exhibit the non-vanishing non-Gaussianity in general. Also the perturbation amplitude on smaller scales can be completely different from that on the large scale due to the multiplicity of inflationary phases. These signatures will be a smoking gun of this scenario by the future observations.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2020)·4 citations
28. 28*

    A dark matter telescope probing the 6 to 60 GHz band

    Javier De Miguel-Hernández🇪🇸

    In this article we present the Dark-photons$\&$Axion-Like particles Interferometer (DALI), a novel experiment designed for the detection of photon-mixing cold dark matter in the microwave band between 6 and 60 GHz. DALI is a haloscope for the simultaneous search for axions, ALPs and dark photons, with a number of novelties that make it unique. First, it is a dark matter telescope, with a capacity for pointing, tracking and rastering objects and areas in the sky. This potentially allows one to detect relativistic dark matter particles, substructures and flows, without compromising the simultaneous scanning for dark matter relic particles present in the laboratory. Second, it has been designed using commercial technology. This will allow feasible manufacture at a reasonable cost, thereby mitigating the need for R\&D and facilitating maintenance. Finally, it benefits from a high sensitivity over a broad band of frequencies with only minimal reconfiguration.

    ↳ physics.ins-detastro-ph.HEastro-ph.IMhep-ex+1JCAP(2021)·25 citations
29. 29*

    Symmetric gravitational closure

    Maximilian Düll🇩🇪 · Nils L. Fischer🇩🇪 · Bjoern Malte Schaefer🇩🇪 · Frederic P. Schuller🇳🇱

    We show how to exploit symmetry assumptions to determine the dynamical equations for the particular geometry that underpins given matter field equations. The procedure builds on the gravitational closure equations for matter models without any a priori assumption of symmetry. It suffices to illustrate the symmetrization procedure for a Klein-Gordon field equation on a Lorentzian background, for which one obtains the Friedmann equations, without ever having known Einstein's equations, by careful imposition of maximal cosmological symmetry directly on the pertinent gravitational closure equations. This method of finding the family of symmetry-reduced gravitational field equations that are compatible with given matter dynamics directly generalizes to any Killing symmetry algebra, matter models beyond the standard model and indeed tensorial spacetime geometries beyond Lorentzian metrics.

    ↳ gr-qchep-ph3 citations
30. 30*

    Topological Objects in Holographic QCD

    Hideo Suganuma (Kyoto U.)🇯🇵 · Keiichiro Hori (Kyoto U.)🇯🇵

    We study topological objects in holographic QCD based on the Sakai-Sugimoto model, which is constructed with $N_c$ D4 branes and $N_f$ D8/$\overline{D8}$ branes in the superstring theory, and is infrared equivalent to 1+3 dimensional massless QCD. Using the gauge/gravity duality, holographic QCD is described as 1+4 dimensional U($N_f$) gauge theory in flavor space with a background gravity, and its instanton solutions correspond to baryons. First, using the Witten Ansatz, we reduce holographic QCD into a 1+2 dimensional Abelian Higgs theory in a curved space and consider its topological aspect. We numerically obtain the Abrikosov vortex solution and investigate single baryon properties. Second, we study a single meron and two merons in holographic QCD. The single meron carrying a half-integer baryon number is found to have a infinite energy also in holographic QCD. We propose a new-type baryon excitation of the two-merons oscillation in the extra-direction of holographic QCD.

    ↳ hep-thhep-exhep-phPhys.Scripta(2020)·8 citations
31. 31*

    Early Dark Energy Does Not Restore Cosmological Concordance

    J. Colin Hill🇺🇸 · Evan McDonough🇺🇸 · Michael W. Toomey🇺🇸 · Stephon Alexander🇺🇸

    Current cosmological data exhibit a tension between inferences of the Hubble constant, $H_0$, derived from early and late-universe measurements. One proposed solution is to introduce a new component in the early universe, which initially acts as "early dark energy" (EDE), thus decreasing the physical size of the sound horizon imprinted in the cosmic microwave background (CMB) and increasing the inferred $H_0$. Previous EDE analyses have shown this model can relax the $H_0$ tension, but the CMB-preferred value of the density fluctuation amplitude, ${\sigma }_8$, increases in EDE as compared to $\Lambda$CDM, increasing tension with large-scale structure (LSS) data. We show that the EDE model fit to CMB and SH0ES data yields scale-dependent changes in the matter power spectrum compared to $\Lambda$CDM, including $10\%$ more power at $k=1h$/Mpc. Motivated by this observation, we reanalyze the EDE scenario, considering LSS data in detail. We also update previous analyses by including $Planck$ 2018 CMB likelihoods, and perform the first search for EDE in $Planck$ data alone, which yields no evidence for EDE. We consider several data set combinations involving the primary CMB, CMB lensing, SNIa, BAO, RSD, weak lensing, galaxy clustering, and local distance-ladder data (SH0ES). While the EDE component is weakly detected (3$\sigma$) when including the SH0ES data and excluding most LSS data, this drops below 2$\sigma$ when further LSS data are included. Further, this result is in tension with strong constraints imposed on EDE by CMB and LSS data without SH0ES, which show no evidence for this model. We also show that physical priors on the fundamental scalar field parameters further weaken evidence for EDE. We conclude that the EDE scenario is, at best, no more likely to be concordant with all current cosmological data sets than $\Lambda$CDM, and appears unlikely to resolve the $H_0$ tension.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2020)·397 citations
32. 32*

    Hydrodynamic attractors in phase space

    Michal P. Heller🇩🇪 · Ro Jefferson🇩🇪 · Michał Spaliński🇵🇱 · Viktor Svensson🇩🇪

    Hydrodynamic attractors have recently gained prominence in the context of early stages of ultra-relativistic heavy-ion collisions at the RHIC and LHC. We critically examine the existing ideas on this subject from a phase space point of view. In this picture the hydrodynamic attractor can be seen as a special case of the more general phenomenon of dynamical dimensionality reduction of phase space regions. We quantify this using Principal Component Analysis. Furthermore, we adapt the well known slow-roll approximation to this setting. These techniques generalize easily to higher dimensional phase spaces, which we illustrate by a preliminary analysis of a dataset describing the evolution of a 5-dimensional manifold of initial conditions immersed in a 16-dimensional representation of the phase space of the Boltzmann kinetic equation in the relaxation time approximation.

    ↳ hep-thhep-phnucl-thPRL(2020)·47 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.