Wed·May 23, 2018Wednesday·May 23, 2018

1. 01*

   Collider Bounds on 2-Higgs Doublet Models with $U(1{)}_X$ Gauge Symmetries

   Daniel A. Camargo🇧🇷 · Luigi Delle Rose🇮🇹 · Stefano Moretti🇬🇧 · Farinaldo S. Queiroz🇧🇷

   2-Higgs Doublet Models (2HDMs) typically need to invoke an ad-hoc discrete symmetry to avoid severe flavor bounds and in addition feature massless neutrinos, thus falling short of naturally complying with existing data. However, when augmented by an Abelian gauge symmetry naturally incorporating neutrino masses via a type-I seesaw mechanism while at the same time escaping flavor changing interactions, such enlarged 2HDMs become very attractive phenomenologically. In such frameworks, the distinctive element is the $Z^{\prime }$ gauge boson generated by the spontaneous breaking of the Abelian group $U(1{)}_X$. In this work, we derive updated collider bounds on it. Several theoretical setups are possible, each with different and sometimes suppressed couplings to quarks and leptons. Thus, complementary data from dijet and dilepton resonance searches need to be considered to fully probe these objects. We employ the corresponding datasets as obtained at the Large Hadron Collider (LHC) at the 13 TeV CMs energy for $\mathcal{L}=12,36$ and $300$ fb${}^{-1}$ of luminosity. Moreover, we present the potential sensitivity to such $Z^{\prime }$s of the High Luminosity LHC (HL-LHC) and High Energy LHC (HE-LHC).

   hep-phPLB(2019)·26 citations
2. 02*

   Asymmetric Dark Matter, Inflation and Leptogenesis from B-L Symmetry Breaking

   P. V. Dong🇻🇳 · D. T. Huong🇻🇳 · Daniel A. Camargo🇧🇷 · Farinaldo S. Queiroz🇧🇷 · José W. F. Valle🇪🇸

   We propose a unified setup for dark matter, inflation and baryon asymmetry generation through the neutrino mass seesaw mechanism. Our scenario emerges naturally from an extended gauge group containing $B-L$ as a non-commutative symmetry, broken by a singlet scalar that also drives inflation. Its decays reheat the universe, producing the lightest right-handed neutrino. Automatic matter parity conservation leads to the stability of an asymmetric dark matter candidate, directly linked to the matter-antimatter asymmetry in the universe.

   hep-phPRD(2019)·34 citations
3. 03*

   E6 inspired SUSY models with Custodial Symmetry

   R. Nevzorov🇷🇺

   The breakdown of E_6 within the supersymmetric (SUSY) Grand Unified Theories (GUTs) can result in SUSY extensions of the standard model (SM) based on the SM gauge group together with extra U(1) gauge symmetry under which right-handed neutrinos have zero charge. In these U(1)_N extensions of the minimal supersymmetric standard model (MSSM) a single discrete \tilde{Z}^H_2 symmetry may be used to suppress the most dangerous operators, that give rise to proton decay as well as non-diagonal flavour transitions at low energies. The SUSY models under consideration involves Z' and extra exotic matter beyond the MSSM. We discuss leptogenesis within this SUSY model and argue that the extra exotic states may lead to the non--standard Higgs decays.

   hep-phInt.J.Mod.Phys.A(2018)·11 citations
4. 04*

   $K^{\ast }$ mesons with hidden charm arising from $KX(3872)$ and $K{Z}_c(3900)$ dynamics

   Xiu-Lei Ren🇩🇪 · Brenda B. Malabarba🇧🇷 · Li-Sheng Geng🇨🇳 · K. P. Khemchandani🇧🇷 · A. Martinez Torres🇧🇷

   Inspired by the recent discovery of the pentaquark states $P_c(4450)$ and $P_c(4380)$, which can be viewed as excited nucleon states with hidden charm, we study the three-body interaction of a kaon and a pair of $D{\bar{D}}^{\ast }$ in isospin 0 and 1. We show that the two body interactions stringently constrained by the existence of the $D_{s0}^{\ast }(2317)$, $D_{s1}^{\ast }(2460)$, $X(3872)$, and $Z_c(3900)$, which are widely believed to contain large $DK$, $D^{\ast }K$, and $D{\bar{D}}^{\ast }$ components, inevitably lead to the existence of a heavy $K^{\ast }$ meson with hidden charm. Concrete coupled channel three-body calculations yield its mass and width as $(4307\pm 2)-i(9\pm 2)$ MeV with $I(J^P)=1/2(1^{-})$. This state, if found experimentally, definitely cannot be accommodated in a $q\bar{q}$ picture, and therefore presents a clear case of an exotic hadron.

   hep-phnucl-thPLB(2018)·50 citations
5. 05*

   $D\Xi$ and $D^{\ast }\Xi$ Molecular States from One Boson Exchange

   Ming-Zhu Liu🇨🇳 · Tian-Wei Wu🇨🇳 · Ju-Jun Xie🇨🇳 · Manuel Pavon Valderrama🇨🇳 · Li-Sheng Geng🇨🇳

   We explore the existence of $D\Xi$ and $D^{\ast }\Xi$ molecular states within the one boson exchange model. We regularize the potential derived in this model with a form factor and a cut-off of the order of $1\mathrm{GeV}$. To determine the cut-off, we use the condition that the $X(3872)$ is reproduced as a pole in the $J^{PC}=1^{++}$ $D^{\ast }\bar{D}$ amplitude. From this we find that the $J^P={\frac{1}{2}}^{-}$ $D^{\ast }\Xi$ system is on the verge of binding and has an unnaturally large scattering length. For the $J^P={\frac{1}{2}}^{-}$ $D\Xi$ and the $J^P={\frac{3}{2}}^{-}$ $D^{\ast }\Xi$ systems the attraction is not enough to form a bound state. From heavy quark symmetry and the quark model we can extend the previous model to the $P{\Xi }_{QQ}$ and $P^{\ast }{\Xi }_{QQ}$ systems, with $P=D,\bar{B}$, $P^{\ast }=D^{\ast },{\bar{B}}^{\ast }$ and ${\Xi }_{QQ}={\Xi }_{cc},{\Xi }_{bb}$. In this case we predict a series of triply heavy pentaquark-like molecules.

   hep-phhep-exnucl-thPRD(2018)·37 citations
6. 06*

   A light singlet at the LHC and DM

   Jan Kalinowski🇵🇱

   An interesting scenario of an R-symmetric supersymmetric model with a light singlet is discussed. Since a light scalar in this model necessarily implies a light Dirac neutralino, its viability as a dark matter candidate is addressed.

   hep-phastro-ph.HEhep-exPoS(2018)·0 citations
7. 07*

   Null tests from angular distributions in $D\to P_1{P}_2{l}^{+}{l}^{-}$, $l=e,\mu$ decays on and off peak

   Stefan de Boer🇩🇪 · Gudrun Hiller🇩🇪

   We systematically analyze the full angular distribution in $D\to P_1{P}_2{l}^{+}{l}^{-}$ decays, where $P_{1,2}=\pi ,K$, $l=e,\mu$. We identify several null tests of the standard model (SM). Notably, the angular coefficients $I_{5,6,7}$, driven by the leptons' axial-vector coupling $C_{10}^{(\prime )}$, vanish by means of a superior GIM-cancellation and are protected by parity invariance below the weak scale. CP-odd observables related to the angular coefficients $I_{5,6,8,9}$ allow to measure CP-asymmetries without $D$-tagging. The corresponding observables $A_{5,6,8,9}$ constitute null tests of the SM. Lepton universality in $|\Delta c|=|\Delta u|=1$ transitions can be tested by comparing $D\to P_1{P}_2{\mu }^{+}{\mu }^{-}$ to $D\to P_1{P}_2{e}^{+}{e}^{-}$ decays. Data for $P_1{P}_2={\pi }^{+}{\pi }^{-}$ and $K^{+}{K}^{-}$ on muon modes are available from LHCb and on electron modes from BESIII. Corresponding ratios of dimuon to dielectron branching fractions are at least about an order of magnitude away from probing the SM. In the future electron and muon measurements should be made available for the same cuts as corresponding ratios $R_{P_1{P}_2}^D$ provide null tests of $e$-$\mu$-universality. We work out beyond-SM signals model-independently and in SM extensions with leptoquarks.

   hep-phhep-exPRD(2018)·66 citations
8. 08*

   MoMEMta, a modular toolkit for the Matrix Element Method at the LHC

   Sébastien Brochet🇧🇪 · Christophe Delaere🇧🇪 · Brieuc François🇧🇪 · Vincent Lemaître🇧🇪 · Alexandre Mertens🇧🇪 · Alessia Saggio🇧🇪 · Miguel Vidal Marono🇧🇪 · Sébastien Wertz🇧🇪

   The Matrix Element Method has proven to be a powerful method to optimally exploit the information available in detector data. Its widespread use is nevertheless impeded by its complexity and the associated computing time. MoMEMta, a C++ software package to compute the integrals at the core of the method, provides a versatile implementation of the Matrix Element Method to both the theory and experiment communities. Its modular structure covers the needs of experimental analysis workflows at the LHC without compromising ease of use on simpler and smaller simulated samples used for phenomenological studies. With respect to existing tools, MoMEMta improves on usability and flexibility. In this paper, we present version 1.0 of MoMEMta, together with examples illustrating the wide range of applications at the LHC accessible for the first time with a single tool.

   hep-phhep-exEPJC(2019)·25 citations
9. 09*

   Phenomenology of GeV-scale Heavy Neutral Leptons

   Kyrylo Bondarenko🇳🇱 · Alexey Boyarsky🇳🇱 · Dmitry Gorbunov🇷🇺 · Oleg Ruchayskiy🇩🇰

   We review and revise phenomenology of the GeV-scale heavy neutral leptons (HNLs). We extend the previous analyses by including more channels of HNLs production and decay and provide with more refined treatment, including QCD corrections for the HNLs of masses $\mathcal{O}(1)$ GeV. We summarize the relevance of individual production and decay channels for different masses, resolving a few discrepancies in the literature. Our final results are directly suitable for sensitivity studies of particle physics experiments (ranging from proton beam-dump to the LHC) aiming at searches for heavy neutral leptons.

   hep-phhep-exJHEP(2018)·299 citations
10. 10*

    Flavorful Two Higgs Doublet Models with a Twist

    Wolfgang Altmannshofer🇺🇸 · Brian Maddock🇺🇸

    We explore Two Higgs Doublet Models with non-standard flavor structures. In analogy to the four, well studied, models with natural flavor conservation (type 1, type 2, lepton-specific, flipped), we identify four models that preserve an approximate $U(2{)}^5$ flavor symmetry acting on the first two generations. In all four models, the couplings of the 125 GeV Higgs are modified in characteristic flavor non-universal ways. The heavy neutral and charged Higgs bosons show an interesting non-standard phenomenology. We discuss their production and decay modes and identify the most sensitive search channels at the LHC. We study the effects on low energy flavor violating processes finding relevant constraints from $B_d$ and $B_s$ meson oscillations and from the rare decay $B_s\to {\mu }^{+}{\mu }^{-}$. We also find that lepton flavor violating $B$ meson decays like $B_s\to \tau \mu$ and $B\to K^{(\ast )}\tau \mu$ might have branching ratios at an observable level.

    hep-phPRD(2018)·27 citations
11. 11*

    The QCD Axion Window and Low Scale Inflation

    Fuminobu Takahashi🇯🇵 · Wen Yin🇨🇳 · Alan H. Guth🇺🇸

    We show that the upper bound of the classical QCD axion window can be significantly relaxed for low-scale inflation. If the Gibbons-Hawking temperature during inflation is lower than the QCD scale, the initial QCD axion misalignment angle follows the Bunch-Davies distribution. The distribution is peaked at the strong CP conserving minimum if there is no other light degree of freedom contributing to the strong CP phase. As a result, the axion overproduction problem is significantly relaxed even for an axion decay constant larger than $10^{12}$GeV. We also provide concrete hilltop inflation models where the Hubble parameter during inflation is comparable to or much smaller than the QCD scale, with successful reheating taking place via perturbative decays or dissipation processes.

    hep-phgr-qchep-exPRD(2018)·194 citations
12. 12*

    Small-$x$ phenomenology at the LHC and beyond: HELL 3.0 and the case of the Higgs cross section

    Marco Bonvini🇮🇹

    Small-$x$ resummation has been proven recently to be a crucial ingredient for describing small-$x$ HERA data, and the inclusion of small-$x$ resummation in parton distribution function (PDF) determination has a sizeable effect on the PDFs even at the electroweak scale. In this work we explore the implications of small-$x$ resummation at the Large Hadron Collider (LHC) and at a Future Circular Collider (FCC). We construct the theoretical machinery for resumming physical inclusive observables at hadron colliders, and describe its implementation in the public code HELL 3.0. We focus on Higgs production in gluon fusion as a prototypical example, both because it is sensitive to small-$x$ gluons and because of its importance for the LHC physics programme. We find that adding small-$x$ resummation to the N${}^3$LO Higgs production cross section can lead to an increase of up to 10% at FCC, while the effect is smaller (+1%) at LHC but still important to achieve a high level of precision.

    hep-phEPJC(2018)·52 citations
13. 13*

    The stochastic gravitational-wave background in the absence of horizons

    Enrico Barausse🇫🇷 · Richard Brito🇩🇪 · Vitor Cardoso🇵🇹 · Irina Dvorkin🇩🇪 · Paolo Pani🇮🇹

    Gravitational-wave astronomy has the potential to explore one of the deepest and most puzzling aspects of Einstein's theory: the existence of black holes. A plethora of ultracompact, horizonless objects have been proposed to arise in models inspired by quantum gravity. These objects may solve Hawking's information-loss paradox and the singularity problem associated with black holes, while mimicking almost all of their classical properties. They are, however, generically unstable on relatively short timescales. Here, we show that this "ergoregion instability" leads to a strong stochastic background of gravitational waves, at a level detectable by current and future gravitational-wave detectors. The absence of such background in the first observation run of Advanced LIGO already imposes the most stringent limits to date on black-hole alternatives, showing that certain models of "quantum-dressed" stellar black holes can be at most a small percentage of the total population. The future LISA mission will allow for similar constraints on supermassive black-hole mimickers.

    ↳ gr-qcastro-ph.HEhep-phClass.Quant.Grav.(2018)·73 citations
14. 14*

    Baryons under Strong Magnetic Fields or in Theories with Space-dependent $\theta$-term

    Dimitrios Giataganas🇹🇼

    Baryonic states are sufficiently complex to reveal physics that is hidden in the mesonic bound states. Using gauge/gravity correspondence we study analytically and numerically baryons in theories with space-dependent $\theta$-term, or theories under strong magnetic fields. Such holographic studies on baryons are accommodated in a generic analytic framework we develop for anisotropic theories, where their qualitative features are common irrespective of the source that triggers the anisotropy. We find that the distribution of the quarks forming the state, depends on the angle between the baryon and the anisotropic direction. Its shape is increasingly elliptic with respect to the strength of the field sourcing the anisotropy, counterbalancing the broken rotational invariance on the gluonic degrees of freedom. Strikingly, the baryons dissociate in stages with a process that depends on the proximity of the quarks to the anisotropic direction, where certain quark pairs abandon the bound state first, followed by the closest pairs to them as the temperature increases. This observation may also serve as a way to identify the nature of certain exotic states. Finally, we investigate holographic baryons with decreased number of quarks and explain why in theories under consideration the presence of anisotropy does not modify the universal stability condition in contrast to the usual trend.

    ↳ hep-thhep-lathep-phPRD(2018)·10 citations
15. 15*

    The Effective J-Factor of the Galactic Center for Velocity-Dependent Dark Matter Annihilation

    Kimberly K. Boddy🇺🇸 · Jason Kumar🇺🇸 · Louis E. Strigari🇺🇸

    We present the effective $J$-factors for the Milky Way for scenarios in which dark matter annihilation is p-wave or d-wave suppressed. We find that the velocity suppression of dark matter annihilation can have a sizable effect on the morphology of a potential dark matter annihilation signal in the Galactic Center. The gamma-ray flux from the innermost region of the Galactic Center is in particular suppressed. We find that for dark matter density profiles with steep inner slopes, the morphology of the Inner Galaxy gamma-ray emission in p-wave models can be made similar to the morphology in standard s-wave models. This similarity may suggest that model discrimination between s-wave and p-wave is challenging, for example, when fitting the Galactic Center excess. However, we show that it is difficult to simultaneously match s- and p-wave morphologies at both large and small angular scales. The $J$-factors we calculate may be implemented with astrophysical foreground models to self-consistently determine the morphology of the excess with velocity-suppressed dark matter annihilation.

    ↳ astro-ph.HEastro-ph.COhep-phPRD(2018)·49 citations
16. 16*

    Testing the universality of free fall towards dark matter with radio pulsars

    Lijing Shao🇩🇪 · Norbert Wex🇩🇪 · Michael Kramer🇩🇪

    The violation of the weak equivalence principle (EP) in the gravitational field of the Earth, described by the Eötvös parameter ${\eta }_{\oplus }$, was recently constrained to the level $\left|{\eta }_{\oplus }\right|\lesssim 10^{-14}$ by the MICROSCOPE space mission. The Eötvös parameter ${\eta }_{\mathrm{DM}}$, pertaining to the differential couplings of dark matter (DM) and ordinary matter, was only tested to the level $\left|{\eta }_{\mathrm{DM}}\right|\lesssim 10^{-5}$ by the Eöt-Wash group and lunar laser ranging. This test is limited by the EP-violating driving force in the Solar neighborhood that is determined by the Galactic distribution of DM. Here we propose a novel celestial experiment using the orbital dynamics from radio timing of binary pulsars, and obtain a competing limit on ${\eta }_{\mathrm{DM}}$ from a neutron star (NS) -- white dwarf (WD) system, PSR J1713+0747. The result benefits from the large material difference between the NS and the WD, and the large gravitational binding energy of the NS. If we can discover a binary pulsar within $\sim 10$ parsecs of the Galactic center, where the driving force is much larger in the expected DM spike, precision timing will improve the test of the universality of free fall towards DM and constrain various proposed couplings of DM to the Standard Model by several orders of magnitude. Such a test probes the hypothesis that gravity is the only long-range interaction between DM and ordinary matter.

    ↳ gr-qcastro-ph.GAhep-phPRL(2018)·32 citations
17. 17*

    Inflation in gauge theory of gravity with local scaling symmetry and quantum induced symmetry breaking

    Yong Tang🇯🇵 · Yue-Liang Wu🇨🇳

    Motivated by the gauge theory of gravity with local scaling symmetry proposed recently in 1712.04537 and 1506.01807, we investigate whether the scalar field therein can be responsible for the inflation. We show that the classical theory would suffer from the difficulty that inflation can start but will never stop. We explore possible solutions by invoking the symmetry breaking through quantum effects. The effective potential of the scalar field is shown to have phenomenologically interesting forms to give viable inflation models. The predictions of physical observables agree well with current cosmological measurements and can be further tested in future experiments searching for primordial gravitational waves.

    ↳ gr-qcastro-ph.COhep-phPLB(2018)·19 citations
18. 18*

    Dark Matter in Quantum Gravity

    Xavier Calmet🇬🇧 · Boris Latosh🇷🇺

    We show that quantum gravity, whatever its ultra-violet completion might be, could account for dark matter. Indeed, besides the massless gravitational field recently observed in the form of gravitational waves, the spectrum of quantum gravity contains two massive fields respectively of spin 2 and spin 0. If these fields are long-lived, they could easily account for dark matter. In that case, dark matter would be very light and only gravitationally coupled to the standard model particles.

    ↳ hep-thgr-qchep-phEPJC(2018)·17 citations
19. 19*

    Model Selection with Strong-lensing Systems

    Kyle Leaf🇺🇸 · Fulvio Melia🇺🇸

    In this paper, we use an unprecedentedly large sample (158) of confirmed strong lens systems for model selection, comparing five well studied Friedmann-Robertson-Walker cosmologies: LCDM, wCDM (the standard model with a variable dark-energy equation of state), the R_h=ct universe, the (empty) Milne cosmology, and the classical Einstein-de Sitter (matter dominated) universe. We first use these sources to optimize the parameters in the standard model and show that they are consistent with Planck, though the quality of the best fit is not satisfactory. We demonstrate that this is likely due to under-reported errors, or to errors yet to be included in this kind of analysis. We suggest that the missing dispersion may be due to scatter about a pure single isothermal sphere (SIS) model that is often assumed for the mass distribution in these lenses. We then use the Bayes information criterion, with the inclusion of a suggested SIS dispersion, to calculate the relative likelihoods and ranking of these models, showing that Milne and Einstein-de Sitter are completely ruled out, while R_h=ct is preferred over LCDM/wCDM with a relative probability of ~73% versus ~24%. The recently reported sample of new strong lens candidates by the Dark Energy Survey, if confirmed, may be able to demonstrate which of these two models is favoured over the other at a level exceeding 3 sigma.

    ↳ astro-ph.COastro-ph.GAgr-qchep-phMNRAS(2018)·23 citations
20. 20*

    Axial anomaly and hadronic properties in a nuclear medium

    G. Fejos🇯🇵 · A. Hosaka🇯🇵

    We investigate meson and nucleon dynamics at finite baryon density and temperature by coupling the nucleon field and the omega meson to the three-flavor linear sigma model and calculate hadronic properties around the nuclear liquid-gas transition. We apply the functional renormalization group method, and find that mesonic fluctuations increase the strength of the coefficient of the $U_A(1)$ breaking determinant operator as a function of the chiral condensate. As a consequence, we find that the actual value of the anomaly increases discontinuously at the first order nuclear liquid-gas transition. We calculate how mesonic masses and partial restoration of chiral symmetry are modified due to such an effect.

    ↳ nucl-thhep-phPRD(2018)·19 citations
21. 21*

    Exploring compensated isocurvature perturbations with CMB spectral distortion anisotropies

    Taku Haga🇯🇵 · Keisuke Inomata🇯🇵 · Atsuhisa Ota🇯🇵 · Andrea Ravenni🇮🇹

    We develop a linear perturbation theory for the spectral $y$-distortions of the cosmic microwave background (CMB). The $y$-distortions generated during the recombination epoch are usually negligible because the energy transfer due to the Compton scattering is strongly suppressed at that time, but they can be significant if there is a considerable amount of compensated isocurvature perturbation (CIP), which is not tightly constrained from the present CMB observations. The linear $y$-distortions explicitly depend on the baryon density fluctuations, therefore $y$ anisotropies can completely resolve the degeneracy between the baryon isocurvature perturbations and the cold dark matter ones. This novel method is free from lensing contaminations that can affect the previous approach to the CIPs based on the nonlinear modulation of the CMB anisotropies. We compute the cross correlation functions of the $y$-distortions with the CMB temperature and the $E$ mode polarization anisotropies. They are sensitive to the correlated CIPs parameterized by $f^{\prime }\equiv {\mathcal{P}}_{\mathrm{CIP}\zeta }/{\mathcal{P}}_{\zeta \zeta }$ with ${\mathcal{P}}_{\zeta \zeta }$ and ${\mathcal{P}}_{\mathrm{CIP}\zeta }$ being the auto correlation of the adiabatic perturbations and the cross correlation between them and the CIPs. We investigate how well the $y$ anisotropies will constrain $f^{\prime }$ in future observations such as those provided by a PIXIE-like and a PRISM-like survey, LiteBIRD and a cosmic variance limited (CVL) survey, taking into account the degradation in constraining power due to the presence of Sunyaev Zel'dovich effect from galaxy clusters. For example, our forecasts show that it is possible to achieve an upper limit of $f^{\prime }<2\times 10^5$ at 68% C.L. with LiteBIRD, and $f^{\prime }<2\times 10^4$ with CVL observations.

    ↳ astro-ph.COgr-qchep-phJCAP(2018)·15 citations
22. 22*

    Looking for Axion Dark Matter in Dwarf Spheroidals

    Andrea Caputo🇪🇸 · Carlos Peña Garay🇪🇸 · Samuel J. Witte🇪🇸

    We study the extent to which the decay of cold dark matter axions can be probed with forthcoming radio telescopes such as the Square Kilometer Array (SKA). In particular we focus on signals arising from dwarf spheroidal galaxies, where astrophysical uncertainties are reduced and the expected magnetic field strengths are such that signals arising from axion decay may dominate over axion-photon conversion in a magnetic field. We show that with $\sim 100$ hours of observing time, SKA could improve current sensitivity by a factor of about five.

    ↳ astro-ph.COhep-phPRD(2018)·91 citations
23. 23*

    On the strong-CP problem and its axion solution in torsionful theories

    Georgios K. Karananas🇩🇪

    Gravitational effects may interfere with the axion solution to the strong-CP problem. We point out that gravity can potentially provide a protection mechanism against itself, in the form of an additional axion-like field associated with torsion.

    ↳ hep-thgr-qchep-phEPJC(2018)·13 citations
24. 24*

    Dark Matter that Interacts with Baryons: Density Distribution within the Earth and New Constraints on the Interaction Cross-section

    David A. Neufeld (JHU)🇺🇸 · Glennys R. Farrar (NYU)🇺🇸 · Christopher F. McKee (UC Berkeley)🇺🇸

    For dark matter (DM) particles with masses in the 0.6 - 6 m_p range, we set stringent constraints on the interaction cross-sections for scattering with ordinary baryonic matter. These constraints follow from the recognition that such particles can be captured by - and thermalized within - the Earth, leading to a substantial accumulation and concentration of DM that interact with baryons. Here, we discuss the probability that DM intercepted by the Earth will be captured, the number of DM particles thereby accumulated over Earth's lifetime, the fraction of such particles retained in the face of evaporation, and the density distribution of such particles within the Earth. In the latter context, we note that a previous treatment of the density distribution of DM, presented by Gould and Raffelt and applied subsequently to DM in the Sun, is inconsistent with considerations of hydrostatic equilibrium. Our analysis provides an estimate of the DM particle density at Earth's surface, which may exceed 1.E+14 cm-3 for the mass range under consideration. Based upon our determination of the DM density at Earth's surface, we derive constraints on the scattering cross-sections. These constraints are placed by four considerations: (1) the lifetime of the relativistic proton beam at the Large Hadron collider (LHC); (2) the orbital decay of spacecraft in low Earth orbit (LEO); (3) the vaporization rate of cryogenic liquids in well-insulated storage dewars; and (4) the thermal conductivity of Earth's crust. As an example application of our results, we show that for the scattering cross-sections that were invoked recently in Barkana's original explanation for the anomalously deep 21 cm absorption reported by EDGES, DM particle masses in the 0.6 - 4 m_p range are ruled out.

    ↳ astro-ph.COhep-phApJ(2018)·58 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.