Mon·Oct 9, 2017Monday·October 9, 2017

1. 01*

   Gravitational self-interactions of a degenerate quantum scalar field

   Sankha S. Chakrabarty🇺🇸 · Seishi Enomoto🇺🇸 · Yaqi Han🇺🇸 · Pierre Sikivie🇺🇸 · Elisa M. Todarello🇺🇸

   We develop a formalism to help calculate in quantum field theory the departures from the description of a system by classical field equations. We apply the formalism to a homogeneous condensate with attractive contact interactions and to a homogeneous self-gravitating condensate in critical expansion. In their classical descriptions, such condensates persist forever. We show that in their quantum description, parametric resonance causes quanta to jump in pairs out of the condensate into all modes with wavector less than some critical value. We calculate in each case the time scale over which the homogeneous condensate is depleted, and after which a classical description is invalid. We argue that the duration of classicality of inhomogeneous condensates is shorter than that of homogeneous condensates.

   hep-phastro-ph.COhep-thPRD(2018)·30 citations
2. 02*

   Axion induced SUSY breaking and focus point gaugino mediation

   Keisuke Harigaya🇺🇸 · Tsutomu T. Yanagida🇯🇵 · Norimi Yokozaki🇯🇵

   We consider a scenario where the supersymmetry breaking and its mediation, and the cancellation of the theta parameter of SU(3)c are all caused by a single chiral multiplet. The string axion multiplet is a natural candidate of such a single superfield. We show that the scenario provides a convincing basis of focus point gaugino mediation, where the electroweak scale is explained with a moderate tuning among the parameters of the theory.

   hep-phPLB(2022)·1 citation
3. 03*

   Isolated photon production in proton-nucleus collisions at forward rapidity

   B. Ducloué🇫🇷 · T. Lappi🇫🇮 · H. Mäntysaari🇺🇸

   We calculate isolated photon production at forward rapidities in proton-nucleus collisions in the Color Glass Condensate framework. Our calculation uses dipole cross sections solved from the running coupling Balitsky-Kovchegov equation with an initial condition fit to deep inelastic scattering data. For comparison, we also update the results for the nuclear modification factor for pion production in the same kinematics. We present predictions for future forward RHIC and LHC measurements at $\sqrt{s_{NN}}=200$ GeV and $\sqrt{s_{NN}}=8$ TeV.

   hep-phnucl-thPRD(2018)·37 citations
4. 04*

   Finite temperature sum rules in the vector channel at finite momentum

   Philipp Gubler🇯🇵 · Daisuke Satow🇩🇪

   Exact sum rules for the longitudinal and transverse part of the vector channel spectral functions at nonzero momentum are derived in the first part of the paper. The sum rules are formulated for the finite temperature spectral functions, from which the vacuum component has been subtracted, and represent a generalization of previous work in which sum rules were derived only for the zero-momentum limit. In the second part of the paper, we demonstrate how the sum rules can be used as constraints in spectral fits to lattice data at various temperatures, with the latest dynamical lattice QCD data at zero momentum.

   hep-phhep-latnucl-thPRD(2017)·8 citations
5. 05*

   Threshold Factorization Redux

   Junegone Chay🇰🇷 · Chul Kim🇰🇷

   We reanalyze the factorization theorems for Drell-Yan process and for deep inelastic scattering near threshold, as constructed in the framework of the soft-collinear effective theory (SCET), from a new, consistent perspective. In order to formulate the factorization near threshold in SCET, we should include an additional degree of freedom with small energy, collinear to the beam direction. The corresponding collinear-soft mode is included to describe the parton distribution function (PDF) near threshold. The soft function is modified by subtracting the contribution of the collinear-soft modes in order to avoid double counting on the overlap region. As a result, the proper soft function becomes infrared finite, and all the factorized parts are free of rapidity divergence. Furthermore, the separation of the relevant scales in each factorized part becomes manifest. We apply the same idea to the dihadron production in $e^{+}{e}^{-}$ annihilation near threshold, and show that the resultant soft function is also free of infrared and rapidity divergences.

   hep-phPRD(2018)·5 citations
6. 06*

   Heavy flavour in high-energy nuclear collisions: overview of transport calculations

   Andrea Beraudo🇮🇹

   Transport calculations are the tool to study medium modifications of heavy-flavour particle distributions in high-energy nuclear collisions. We give a brief overview on their state-of-the art as well as on the questions remaining open, from the evaluation of the transport coefficients to the effects of in-medium hadronization, from the rescattering in the hadronic phase to the possible presence of hot-medium effects also in small systems, like proton-nucleus collisions.

   hep-phnucl-exnucl-thPoS(2017)·0 citations
7. 07*

   Bottomonium suppression using a lattice QCD vetted potential

   Brandon Krouppa🇺🇸 · Alexander Rothkopf🇩🇪 · Michael Strickland🇺🇸

   We estimate bottomonium yields in relativistic heavy-ion collisions using a lattice QCD vetted, complex-valued, heavy-quark potential embedded in a realistic, hydrodynamically evolving medium background. We find that the lattice-vetted functional form and temperature dependence of the proper heavy-quark potential dramatically reduces the dependence of the yields on parameters other than the temperature evolution, strengthening the picture of bottomonium as QGP thermometer. Our results also show improved agreement between computed yields and experimental data produced in RHIC 200 GeV/nucleon collisions. For LHC 2.76 TeV/nucleon collisions, the excited states, whose suppression has been used as a vital sign for quark-gluon-plasma production in a heavy-ion collision, are reproduced better than previous perturbatively-motivated potential models; however, at the highest LHC energies our estimates for bottomonium suppression begin to underestimate the data. Possible paths to remedy this situation are discussed.

   hep-phnucl-exnucl-thPRD(2018)·86 citations
8. 08*

   Vector-like quarks coupling discrimination at the LHC and future hadron colliders

   D. Barducci🇮🇹 · L. Panizzi🇬🇧

   The existence of new coloured states with spin one-half, i.e. extra-quarks, is a striking prediction of various classes of new physics models. Should one of these states be discovered during the 13 TeV runs of the LHC or at future high energy hadron colliders, understanding its properties will be crucial in order to shed light on the underlying model structure. Depending on the extra-quarks quantum number under SU(2)L, their coupling to Standard Model quarks and bosons have either a dominant left- or right-handed chiral component. By exploiting the polarisation properties of the top quarks arising from the decay of pair-produced extra quarks, we show how it is possible to discriminate among the two hypothesis in the whole discovery range currently accessible at the LHC, thus effectively narrowing down the possible interpretations of a discovered state in terms of new physics scenarios. Moreover, we estimate the discovery and discrimination power of future prototype hadron colliders with centre of mass energies of 33 and 100 TeV.

   hep-phhep-exJHEP(2017)·40 citations
9. 09*

   Non-universal $Z^{\prime }$ from Fluxed GUTs

   Miguel Crispim Romao🇬🇧 · Stephen F. King🇬🇧 · George K. Leontaris🇬🇷

   We make a first systematic study of non-universal TeV scale neutral gauge bosons $Z^{\prime }$ arising naturally from a class of F-theory inspired models broken via $SU(5)$ by flux. The phenomenological models we consider may originate from semi-local F-theory GUTs arising from a single $E_8$ point of local enhancement, assuming the minimal ${\mathcal{Z}}_2$ monodromy in order to allow for a renormalisable top quark Yukawa coupling. We classify such non-universal anomaly-free $U(1{)}^{\prime }$ models requiring a minimal low energy spectrum and also allowing for a vector-like family. We discuss to what extent such models can account for the anomalous $B$-decay ratios $R_K$ and $R_{K^{\ast }}$.

   hep-phhep-thPLB(2018)·24 citations
10. 10*

    Test of the multiquark structure of $a_1(1420)$ in strong two-body decays

    Thomas Gutsche🇩🇪 · Mikhail A. Ivanov🇷🇺 · Jürgen G. Körner🇩🇪 · Valery E. Lyubovitskij🇩🇪 · Kai Xu🇩🇪

    We present an analysis of strong two-body decays of the $a_1(1420)$ with $J^{PC}=1^{++}$ recently reported by the COMPASS Collaboration at CERN. Following the interpretation of the COMPASS Collaboration that the $a_1$ is an unusual state with a four-quark $q\bar{q}s\bar{s}$ structure we consider two possible configurations for this state --- hadronic molecular and color diquark-antidiquark structures. We find that the dominant decay mode of the $a_1$ is the decay into $K$ and $K^{\ast }$. In particular, we calculate that the four decay modes $a_1\to VP$ with $VP=K^{\ast \pm }{K}^{\mp }$, $K^{\ast 0}{\bar{K}}^0$, ${\bar{K}}^{\ast 0}{K}^0$ together give a dominant contribution to the measured total width of about 150 MeV. The observational mode $a_1\to f_0(980)+{\pi }^0$ is significantly suppressed by one order of magnitude.

    hep-phPRD(2017)·27 citations
11. 11*

    Naturalness and light Higgsinos: why ILC is the right machine for SUSY discovery

    Suvi-Leena Lehtinen🇩🇪 · Howard Baer🇺🇸 · Mikael Berggren🇩🇪 · Keisuke Fujii🇯🇵 · Jenny List🇩🇪 · Tomohiko Tanabe🇯🇵 · Jacqueline Yan🇯🇵

    Radiatively-driven natural supersymmetry, a theoretically and experimentally well-motivated framework, centers around the predicted existence of four light, nearly mass-degenerate Higgsinos with mass $\sim 100-200$ GeV (not too far above $m_Z$). The small mass splittings amongst the higgsinos, typically 4-20 GeV, results in very little visible energy arising from decays of the heavier higgsinos. Given that other SUSY particles are considerably heavy, this makes detection challenging at hadron colliders. On the other hand, the clean environment of an electron-positron collider with $\sqrt{s}>2m_{higgsino}$ would enable a decisive search of these required higgsinos, and thus either the discovery or exclusion of natural SUSY. We present a detailed simulation study of precision measurements of higgsino masses and production cross sections at $\sqrt{s}$ = 500 GeV of the proposed International Linear Collider currently under consideration for construction in Japan. The study is based on a Geant4 simulation of the International Large Detector concept. We examine several benchmark points just beyond the HL-LHC reach, with four light higgsinos directly accessible by the ILC, and the mass differences between the lightest SUSY particle and the heavier states ranging from about 4 to 20 GeV. It can be shown that their masses and production cross sections can be precisely measured to approximately 1\% precision or better. These precise measurements allow for extracting the underlying weak scale SUSY parameters, giving predictions for the masses of heavier SUSY states. These provide motivation for future high-energy colliders. Additionally, dark matter properties may be derived. Evolution of the measured gaugino masses to high energies should allow testing the hypothesis of gaugino mass unification.

    hep-phPoS(2017)·11 citations
12. 12*

    Gravitational wave as probe of superfluid dark matter

    Rong-Gen Cai🇨🇳 · Tong-Bo Liu🇨🇳 · Shao-Jiang Wang🇨🇳

    In recent years, superfluid dark matter (SfDM) has become a competitive model of emergent modified Newtonian dynamics (MOND) scenario: MOND phenomenons naturally emerge as a derived concept due to an extra force mediated between baryons by phonons as a result of axionlike particles condensed as superfluid at galactic scales; Beyond galactic scales, these axionlike particles behave as normal fluid without phonon-mediated MOND-like force between baryons, therefore SfDM also maintains the usual success of $\Lambda$CDM at cosmological scales. In this paper, we use gravitational waves (GWs) to probe the relevant parameter space of SfDM. GWs through Bose-Einstein condensate (BEC) could propagate with a speed slightly deviation from the speed-of-light due to the change in the effective refractive index, which depends on the SfDM parameters and GW-source properties. We find that Five hundred meter Aperture Spherical Telescope (FAST), Square Kilometre Array (SKA) and International Pulsar Timing Array (IPTA) are the most promising means as GW probe of relevant parameter space of SfDM. Future space-based GW detectors are also capable of probing SfDM if a multimessenger approach is adopted.

    hep-phastro-ph.COgr-qcPRD(2018)·31 citations
13. 13*

    Explosive Axion Production from Saxion

    Yohei Ema🇯🇵 · Kazunori Nakayama🇯🇵

    The dynamics of saxion in a supersymmetric axion model and its effect on the axion production is studied in detail. We find that the axion production is very efficient when the saxion oscillation amplitude is much larger than the Peccei-Quinn scale, due to a spike-like behavior of the effective axion mass. We also consider the axino production and several cosmological consequences. The possibility of detection of gravitational waves from the non-linear dynamics of the saxion and axion is discussed.

    hep-phastro-ph.COPLB(2018)·16 citations
14. 14*

    A Second Look at String-Inspired Models for Proton-Proton Scattering via Pomeron Exchange

    Ziyi Hu🇺🇸 · Brian Maddock🇺🇸 · Nelia Mann🇺🇸

    We re-examine a string dual model for elastic proton-proton scattering via Pomeron exchange. We argue that the method of "Reggeizing" a propagator to take into account an entire trajectory of exchanged particles can be generalized, in particular by modifying the value of the mass-shell parameter in the model. We then fit the generalized model to scattering data at large s and small t. The fitting results are inconclusive, but suggest that a better fit might be obtained by allowing the mass-shell to vary. The model fits the data equally well (roughly) for a wide range of values of the mass-shell parameter, but the other fitting parameters (the slope and intercept of the Regge trajectory, and the coupling constant and dipole mass from the proton-proton-glueball coupling) are then inconsistent with what we expect. On the other hand, using the traditional method of Reggeization generates a weaker fit, but the other parameters obtain more physically reasonable values. In analyzing the fitting results, we also found that our model is more consistent with the sqrt(s) = 1800 GeV coming from the E710 experiment than that coming from the CDF experiment, and that our model has the greatest discrepancy with the data in the range 0.5 GeV^2 < |t| < 0.6 GeV^2, suggesting that the transition from soft Pomeron to hard Pomeron may occur closer to t = -0.5 GeV^2 rather than t = -0.6 GeV^2 as previously thought.

    hep-phhep-thJHEP(2018)·7 citations
15. 15*

    Fully Differential Higgs Pair Production in Association With a $Z$ Boson at Next-to-Next-to-Leading Order in QCD

    Hai Tao Li🇺🇸 · Chong Sheng Li🇨🇳 · Jian Wang🇩🇪

    We present a fully differential next-to-next-to-leading order calculation of the Higgs pair production in association with a $Z$ boson, which is important for probing the trilinear Higgs self-coupling. The next-to-next-to-leading-order corrections enhance the next-to-leading order total cross sections by a factor of $1.2\sim 1.5$, depending on the collider energy, and change the shape of next-to-leading order kinematic distributions. We discuss how to determine the trilinear Higgs self-coupling using our results.

    hep-phhep-exPRD(2018)·16 citations
16. 16*

    Global fits of the scalar singlet model using GAMBIT

    James McKay (for the GAMBIT collaboration)🇬🇧

    The extension of the standard model (SM) by a Higgs portal scalar field is one the simplest dark matter theories. We present here the first results for a global fit to this model using the global and beyond the SM inference tool (GAMBIT). This software enables the combination of dark matter constraints in a statistically consistent manner. In total 15 parameters are varied and the parameter space explored using four different scanning algorithms. The viable parameter space is reduced from previous studies of this model due to the inclusion of the latest direct detection constraints.

    hep-phastro-ph.COPoS(2017)·3 citations
17. 17*

    Quantization of Space-like States in Lorentz-Violating Theories

    Don Colladay🇺🇸

    Lorentz violation frequently induces modified dispersion relations that can yield space-like states that impede the standard quantization procedures. In certain cases, an extended hamiltonian formalism can be used to define observer-covariant normalization factors for field expansions and phase space integrals. These factors extend the theory to include non-concordant frames in which there are negative-energy states. This formalism provides a rigorous way to quantize certain theories containing space-like states and allows for the consistent computation of Cherenkov radiation rates in arbitrary frames and avoids singular expressions.

    hep-phJ.Phys.Conf.Ser.(2018)·3 citations
18. 18*

    Collider phenomenology of HEFT and new Wh and Zh resonances

    Antonio Dobado🇪🇸 · Felipe J. Llanes-Estrada🇪🇸 · Juan J. Sanz-Cillero🇪🇸

    We report computations of the production cross-section of longitudinal electroweak and Higgs boson pairs within Effective Field Theory for the Electroweak sector (including the Higgs). We have recently reported theoretical studies of gauge boson-gauge boson and Higgs-Higgs resonance production with various quantum numbers. We are now focusing on gauge boson-Higgs boson two-body axial-vector resonances and show a typical cross section. At last, we point out that photon-photon production has also been studied (in $e^{-}{e}^{+}$ as well as pp machines), as this is a very clean process allowing access to scalar and tensor resonances.

    hep-phPoS(2018)·2 citations
19. 19*

    First SUSY results with GAMBIT

    Anders Kvellestad (for the GAMBIT collaboration)🇸🇪

    Based on arXiv:1705.07935 and arXiv:1705.07917, we present the first global fits of supersymmetric models using the new Global And Modular Beyond-the-Standard-Model Inference Tool (GAMBIT). With GAMBIT we have performed frequentist fits of the GUT-scale CMSSM, NUHM1 and NUHM2 models, as well as the weak-scale MSSM7, extending existing results in terms of the number of observables included, scanning techniques and treatment of nuisance parameters. For the GUT-scale models our analyses show that a stop co-annihilation scenario provides the best fit to current data, and that in the CMSSM the stau co-annihilation scenario is ruled out at 95% confidence level. For the MSSM7 we find that the best-fit scenario has light higgsinos and highly under-abundant relic density due to efficient chargino co-annihilation.

    hep-phPoS(2017)·4 citations
20. 20*

    Improved bound on isotropic Lorentz violation in the photon sector from extensive air showers

    F.R. Klinkhamer🇩🇪 · M. Niechciol🇩🇪 · M. Risse🇩🇪

    Cosmic rays have extremely high particle energies (up to $10^{20}\text{eV}$) and can be used to search for violations of Lorentz invariance. We consider isotropic nonbirefringent Lorentz violation in the photon sector for the case of a photon velocity larger than the maximum attainable velocity of the standard fermions. Up to now, Earth-based bounds on this type of Lorentz violation have been determined from observations of TeV gamma rays. Here, we elaborate on a novel approach to test Lorentz invariance with greatly improved sensitivity. This approach is based on investigating extensive air showers which are induced by cosmic-ray particles in the Earth's atmosphere. We study the impact of two Lorentz-violating decay processes on the longitudinal development of air showers, notably the atmospheric depth of the shower maximum $X_{\text{max}}$. Specifically, the two Lorentz-violating decay processes considered are photon decay into an electron-positron pair and modified neutral-pion decay into two photons. We use Monte Carlo simulations performed with the CONEX code which was extended to include these two Lorentz-violating decay processes at a magnitude allowed by the best previous Earth-based bound. Compared to standard physics, these Lorentz-violating decay processes reduce the average $X_{\text{max}}$ for showers with primary energies above $10^{18}\text{eV}$ by an amount that is significantly larger than the average resolution of current air shower experiments. Comparing the simulations of the average $X_{\text{max}}$ to observations, new Earth-based bounds on this type of Lorentz violation are obtained, which are better than the previous bounds by more than three orders of magnitude. Prospects of further studies are also discussed.

    hep-phastro-ph.HEPRD(2017)·26 citations
21. 21*

    Higgs effective $H{l}_i{l}_j$ vertex from heavy ${\nu }_R$ and applications to LFV phenomenology

    Maria J. Herrero🇪🇸 · Ernesto Arganda🇦🇷 · Xabier Marcano🇫🇷 · Roberto Morales🇦🇷 · Alejandro Szynkman🇦🇷

    We present a new computation of the Lepton Flavor Violating effective vertex involving the Higgs boson and two leptons with different flavors. This vertex is generated from the integration to one-loop level of the heavy right handed neutrinos which are considered here within the context of the Low Scale Seesaw Models and with masses close to the TeV scale. We apply the Mass Insertion Approximation technique to compute the loop contributions from these heavy ${\nu }_R$ and derive a symple analytical formula for the $H{l}_i{l}_j$ effective vertex in terms of the input $Y_{\nu }$ Yukawa coupling matrix and right handed $M_R$ neutrino masses. Some interesting phenomenological applications of this $H{l}_i{l}_j$ effective vertex are also included.

    hep-phPoS(2017)·2 citations
22. 22*

    Distinguishing charged Higgs bosons from different representations at the LHC

    Priyotosh Bandyopadhyay🇮🇳 · Antonio Costantini🇮🇹

    Extending the Standard Model (SM) scalar sector via one or multiple Higgs field(s) in higher representation brings one or more charged Higgs bosons in the spectrum. Some of these gauge representations with appropriate hypercharge can bring up doubly charged Higgs boson and can be easily distinguished from the existing models with only singly charged Higgs boson. In this study we focus on distinguishing the singly charged Higgs bosons from different representations, viz. doublets and triplets of $SU(2{)}_L$ gauge group. We consider a supersymmetric extension of SM with a gauge singlet and $SU(2{)}_L$ triplet with $Y=0$ as a benchmark scenario with the possibility of rich phenomenology due to existence of light pseudoscalar for $Z_3$ symmetric superpotential. A detailed collider simulation considering all the SM backgrounds has been carried out in order to classify the final states which are favourable to charged Higgs boson from one particular representation than others. We show that such different representations can be probed an distinguished via looking at single charged Higgs boson phenomenology at the LHC with 14 TeV center of mass energy within $\sim 50$ fb${}^{-1}$ of integrated luminosity.

    hep-phhep-exJHEP(2018)·16 citations
23. 23*

    Nuclear spin dependence of time reversal invariance violating effects in neutron scattering

    Vladimir Gudkov🇺🇸 · Hirohiko M. Shimizu🇯🇵

    The spin structure of parity violating and time reversal invariance violating effects in neutron scattering is discussed. The explicit relations between these effects are presented in terms of functions nuclear spins and neutron partial widths of p-wave resonances.

    ↳ nucl-thhep-phPRC(2018)·23 citations
24. 24*

    Measuring growth index in a universe with massive neutrinos: A revisit of the general relativity test with the latest observations

    Ming-Ming Zhao🇨🇳 · Jing-Fei Zhang🇨🇳 · Xin Zhang

    We make a consistency test for the general relativity (GR) through measuring the growth index $\gamma$ in a universe with massive (sterile/active) neutrinos. We employ the redshift space distortion measurements to do the analysis. To constrain other cosmological parameters, we also use other cosmological measurements, including the Planck 2015 cosmic microwave background temperature and polarization data, the baryon acoustic oscillation data, the type Ia supernova JLA data, the weak lensing galaxy shear data, and the Planck 2015 lensing data. In a universe with massive sterile neutrinos, we obtain $\gamma =0.624_{-0.050}^{+0.055}$, with the tension with the GR prediction $\gamma =0.55$ at the 1.48$\sigma$ level, showing that the consideration of sterile neutrinos still cannot make the true measurement of $\gamma$ be well consistent with the GR prediction. In a universe with massive active neutrinos, we obtain $\gamma =0.663\pm 0.045$ for the normal hierarchy case, $\gamma =0.661_{-0.050}^{+0.044}$ for the degenerate hierarchy case, and $\gamma =0.668_{-0.051}^{+0.045}$ for the inverted hierarchy case, with the tensions with GR all at beyond the 2$\sigma$ level. We find that the consideration of massive active neutrinos (no matter what mass hierarchy is considered) almost does not influence the measurement of the growth index $\gamma$.

    ↳ astro-ph.COgr-qchep-phPLB(2018)·42 citations
25. 25*

    Point Particle Motion in DFT and a Singularity-Free Cosmological Solution

    Robert Brandenberger🇨🇦 · Renato Costa🇿🇦 · Guilherme Franzmann🇨🇦 · Amanda Weltman🇿🇦

    We generalize the action for point particle motion to a double field theory background. After deriving the general equations of motion for these particle geodesics, we specialize to the case of a cosmological background with vanishing antisymmetric tensor field and constant dilaton. We then show that the geodesics can be extended to infinity in both time directions once we define the appropriate physical clock. Following this prescription, we also show the existence of a singularity-free cosmological solution.

    ↳ hep-thastro-ph.COgr-qchep-phPRD(2018)·22 citations
26. 26*

    Detectability of dark matter subhalos by means of the GAMMA-400 telescope

    A. E. Egorov🇷🇺 · A. M. Galper🇷🇺 · N. P. Topchiev🇷🇺 · A. A. Leonov🇷🇺 · S. I. Suchkov🇷🇺 · M. D. Kheymits🇷🇺 · Yu. T. Yurkin🇷🇺

    We investigated the detectability of Galactic subhalos with masses $(10^6-10^9)M_{\odot }$ formed by annihilating WIMP dark matter by the planned GAMMA-400 gamma-ray telescope. The inner structure of dark matter subhalos and their distribution in the Galaxy were taken from corresponding simulations. We showed that the expected gamma-ray flux from subhalos strongly depends on WIMP mass and subhalo concentration, but less strongly depends on the subhalo mass. In an optimistic case we may expect the flux of 10-100 ph/year above 100 MeV from the closest and most massive subhalos, which would be detectable sources for GAMMA-400. However, resolving the inner structure of subhalos might be possible only by the joint analysis of the future GAMMA-400 data and data from other telescopes due to smallness of fluxes. Also we considered the recent subhalo candidates 3FGL J2212.5+0703 and J1924.8-1034 within the framework of our model. We concluded that it is very unlikely that these sources belong to the subhalo population.

    ↳ astro-ph.HEhep-phPhys.Atom.Nucl.(2018)·9 citations
27. 27*

    Electric Dipole Moments of the Atoms, Molecules, Nuclei and Particles

    Timothy Chupp🇺🇸 · Peter Fierlinger🇩🇪 · Michael Ramsey-Musolf🇺🇸 · Jaideep Singh🇺🇸

    A permanent electric dipole moment (EDM) of a particle or system is a separation of charge along its angular-momentum axis and is a direct signal of T-violation and, assuming CPT symmetry, CP violation. For over sixty years EDMs have been studied, first as a signal of a parity-symmetry violation and then as a signal of CP violation that would clarify its role in nature and in theory. Contemporary motivations include the role that CP violation plays in explaining the cosmological matter-antimatter asymmetry and the search for new physics. Experiments on a variety of systems have become ever-more sensitive, but provide only upper limits on EDMs, and theory at several scales is crucial to interpret these limits. Nuclear theory provides connections from Standard-Model and Beyond-Standard-Model physics to the observable EDMs, and atomic and molecular theory reveal how CP-violation is manifest in these systems. EDM results in hadronic systems require that the Standard Model QCD parameter of $\bar{\theta }$ must be exceptionally small, which could be explained by the existence of axions - also a candidate dark-matter particle. Theoretical results on electroweak baryogenesis show that new physics is needed to explain the dominance of matter in the universe. Experimental and theoretical efforts continue to expand with new ideas and new questions, and this review provides a broad overview of theoretical motivations and interpretations as well as details about experimental techniques, experiments, and prospects. The intent is to provide specifics and context as this exciting field moves forward.

    ↳ physics.atom-phhep-phnucl-exnucl-thRMP(2019)·483 citations
28. 28*

    A novel measurement of $B_s^0$ and $D_s^{-}$ lifetimes using semileptonic decays at LHCb

    Diego Tonelli (for the LHCb Collaboration)🇮🇹

    I report new, world-leading LHCb results on heavy meson lifetimes. We use a novel approach that suppresses the shortcomings typically associated with reconstruction of semileptonic decays, allowing for precise measurements of lifetimes and other properties in collider experiments. We achieve a 15% and a $2\times$ improvement over current best determinations of the flavor-specific $B_s^0$ lifetime and $D_s^{-}$ lifetime, respectively.

    ↳ hep-exhep-ph0 citations
29. 29*

    Planck 2015 constraints on the non-flat XCDM inflation model

    Junpei Ooba🇯🇵 · Bharat Ratra🇺🇸 · Naoshi Sugiyama🇯🇵

    We study Planck 2015 cosmic microwave background (CMB) anisotropy data using the energy density inhomogeneity power spectrum generated by quantum fluctuations during an early epoch of inflation in the non-flat XCDM model. Here dark energy is parameterized using a fluid with a negative equation of state parameter but with the speed of fluid acoustic inhomogeneities set to the speed of light. We use this simple parameterization of dynamical dark energy, that is relatively straightforward to use in a computation, in a first attempt to gain some insight into how dark energy dynamics and non-zero spatial curvature jointly affect the CMB anisotropy data constraints. Unlike earlier analyses of non-flat models, we use a physically consistent power spectrum for energy density inhomogeneities. We find that the Planck 2015 data in conjunction with baryon acoustic oscillation measurements are reasonably well fit by a closed XCDM model in which spatial curvature contributes a percent of the current cosmological energy density budget. In this model, the measured Hubble constant and non-relativistic matter density parameter are in good agreement with values determined using most other data. Depending on parameter values, the closed XCDM model has reduced power, relative to the tilted, spatially-flat $\Lambda$CDM case, and appears to partially alleviate the low multipole CMB temperature anisotropy deficit and can help partially reconcile the CMB anisotropy and weak lensing ${\sigma }_8$ constraints, at the expense of somewhat worsening the fit to higher multipole CMB temperature anisotropy data. However, the closed XCDM inflation model does not seem to improve the agreement much, if at all, compared to the closed $\Lambda$CDM inflation case, even though it has one more free parameter. Our results are interesting but tentative; a more thorough analysis is needed to properly gauge their significance.

    ↳ astro-ph.COgr-qchep-phhep-thApJ(2018)·74 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.