Tue·Jul 10, 2018Tuesday·July 10, 2018

1. 01*

   Supersymmetric Dirac-Born-Infeld Axionic Inflation and Non-Gaussianity

   Pran Nath🇺🇸 · Maksim Piskunov🇺🇸

   An analysis is given of inflation based on a supersymmetric Dirac-Born-Infeld (DBI) action in an axionic landscape. The DBI model we discuss involves a landscape of chiral superfields with one $U(1)$ shift symmetry which is broken by instanton type non-perturbative terms in the superpotential. Breaking of the shift symmetry leads to one pseudo-Nambu-Goldstone-boson which acts as the inflaton while the remaining normalized phases of the chiral fields generically labeled axions are invariant under the $U(1)$ shift symmetry. The analysis is carried out in the vacuum with stabilized saxions, which are the magnitudes of the chiral fields. Regions of the parameter space where slow-roll inflation occurs are exhibited and the spectral indices as well as the ratio of the tensor to the scalar power spectrum are computed. An interesting aspect of supersymmetric DBI models analyzed is that in most of the parameter space tensor to scalar ratio and scalar spectral index are consistent with Planck data if slow roll occurs and is not eternal. Also interesting is that the ratio of the tensor to the scalar power spectrum can be large and can lie close to the experimental upper limit and thus testable in improved experiment. Non-Gaussianity in this class of models is explored.

   hep-phastro-ph.COgr-qchep-thJHEP(2019)·7 citations
2. 02*

   Quasi-two-body decays $B_{(s)}\to P{f}_2(1270)\to P\pi \pi$ in the perturbative QCD approach

   Ya Li🇨🇳 · Ai-Jun Ma🇨🇳 · Zhou Rui🇨🇳 · Wen-Fei Wang🇨🇳 · Zhen-Jun Xiao🇨🇳

   In this work, we calculate the $CP$-averaged branching ratios and direct $CP$-violating asymmetries of the quasi-two-body decays $B_{(s)}\to P{f}_2(1270)\to P\pi \pi$ with the two-pion distribution amplitude ${\Phi }_{\pi \pi }^{\mathrm{D}}$ by using the perturbative QCD factorization approach, where $P$ represents a light pseudoscalar meson $K,\pi ,\eta$ and ${\eta }^{\prime }$. The relativistic Breit-Wigner formula for the $D$-wave resonance $f_2(1270)$ is adopted to parameterize the timelike form factor $F_{\pi }$, which contains the final state interactions between the pions in the resonant regions. The consistency of theoretical results with data can be achieved by determining the Gegenbauer moments of the $D$-wave two-pion distribution amplitudes. The decay rates for the considered decay modes are generally in the order of $10^{-9}$ to $10^{-6}$. The integrated direct $CP$ asymmetries for the charged modes agree with the {\it BABAR} and Belle measurements. As a by-product, we extract the branching ratios of $B_{(s)}\to P{f}_2(1270)$ from the corresponding quasi-two-body decay modes, which still need experimental tests at the ongoing and forthcoming experiments.

   hep-phhep-exPRD(2018)·33 citations
3. 03*

   Anomalous quartic gauge couplings and unitarization for the vector boson scattering process $pp\to W^{+}{W}^{+}jjX\to {\ell }^{+}{\nu }_{\ell }{\ell }^{+}{\nu }_{\ell }jjX$

   Genessis Perez🇩🇪 · Marco Sekulla🇩🇪 · Dieter Zeppenfeld🇩🇪

   Weak vector boson scattering (VBS) at the LHC provides an excellent source of information on the structure of quartic gauge couplings and possible effects of physics beyond the SM in electroweak symmetry breaking. Parameterizing deviations from the SM within an effective field theory at tree level, the dimension-8 operators, which are needed for sufficiently general modeling, lead to unphysical enhancements of cross sections within the accessible energy range of the LHC. Preservation of unitarity limits is needed for phenomenological studies of the $VVjj$ events which signify VBS. Here we develop a numerical unitarization scheme for the full off-shell VBS processes and apply it to same-sign $W$ scattering, i.e. processes like $qq\to qq{W}^{+}{W}^{+}$. The scheme is implemented within the Monte Carlo program VBFNLO, including leptonic decay of the weak bosons and NLO QCD corrections. Distributions differentiating between higher dimensional operators are discussed.

   hep-phEPJC(2018)·64 citations
4. 04*

   Flavored Non-Minimal Left-Right Symmetric Model Fermion Masses and Mixings

   E. A. Garcés🇲🇽 · Juan Carlos Gómez-Izquierdo🇲🇽 · F. Gonzalez-Canales🇲🇽

   A complete study on the fermion masses and flavor mixing is presented in a non-minimal left-right symmetric model (NMLRMS) where the ${\mathbf{S}}_3\otimes {\mathbf{Z}}_2\otimes {\mathbf{Z}}_2^e$ flavor symmetry drives the Yukawa couplings. In the quark sector, the mass matrices possess a kind of the generalized Fritzsch textures that allow us to fit the CKM mixing matrix in good agreement to the last experimental data. In the lepton sector, on the other hand, a soft breaking of the $\mu \leftrightarrow \tau$ symmetry provides a non zero and non maximal reactor and atmospheric angles, respectively. The inverted and degenerate hierarchy are favored in the model where a set of free parameters is found to be consistent with the current neutrino data.

   hep-phEPJC(2018)·25 citations
5. 05*

   Model-Independent Bounds on $R(J/\psi )$

   Thomas D. Cohen🇺🇸 · Henry Lamm🇺🇸 · Richard F. Lebed🇺🇸

   We present a model-independent bound on $R(J/\psi )\equiv \mathcal{B}\mathcal{R}(B_c^{+}\to J/\psi {\tau }^{+}{\nu }_{\tau })/\mathcal{B}\mathcal{R}(B_c^{+}\to J/\psi {\mu }^{+}{\nu }_{\mu })$. This bound is constructed by constraining the form factors through a combination of dispersive relations, heavy-quark relations at zero-recoil, and the limited existing determinations from lattice QCD. The resulting 95\% confidence-level bound, $0.20\le R(J/\psi )\le 0.39$, agrees with the recent LHCb result at $1.3\sigma$, and rules out some previously suggested model form factors.

   hep-phhep-exhep-latnucl-thJHEP(2018)·48 citations
6. 06*

   Prompt neutrinos and intrinsic charm at SHiP

   Weidong Bai🇺🇸 · Mary Hall Reno🇺🇸

   We present a new evaluation of the far-forward neutrino plus antineutrino flux and number of events from charm hadron decays in a 400 GeV proton beam dump experiment like the Search for Hidden Particles (SHiP). Using next-to-leading order perturbative QCD and a model for intrinsic charm, we include intrinsic transverse momentum effects and other kinematic angular corrections. We compare this flux to a far-forward flux evaluated with next-to-leading order perturbative QCD, without intrinsic transverse momentum, that used the angular distribution of charm quarks rather than the neutrinos from their decays. The tau neutrino plus antineutrino number of events in the perturbative QCD evaluation is reduced by a factor of about three when intrinsic transverse momentum and the full decay kinematics are included. We show that intrinsic charm contributions can significantly enhance the number of events from neutrinos from charm hadron decays. Measurements of the number of events from tau neutrino plus antineutrino interactions and of the muon charge asymmetry as a function of energy can be used to constrain intrinsic charm models.

   hep-phJHEP(2019)·25 citations
7. 07*

   CGC/saturation approach: re-visiting the problem of odd harmonics in angular correlations

   E. Gotsman (Tel Aviv U.)🇮🇱 · E. Levin (Tel Aviv U./UTFSM)🇮🇱

   In this paper we demonstrate that the selection of events with different multiplicities of produced particles, leads to the violation of the azimuthal angular symmetry, $\varphi \to \pi -\varphi$. We find for LHC and lower energies, that this violation can be so large for the events with multiplicities $n\ge 2\bar{n}$, where $\bar{n}$ is the mean multiplicity, that it leads to almostno suppression of $v_n$, with odd $n$. However, this can only occur if the typical size of the dipole in DIS with a nuclear target is small, or $Q^2>Q_s^2\text{Lb}A,Y_{\min },b\text{Rb}$, where $Q_s$ is the saturation momentum of the nucleus at $Y=Y_{\min }$. In the case of large sizes of dipoles, when $Q^2<Q_s^2\text{Lb}A,Y_{\min },b\text{Rb}$, we show that $v_n=0$ for odd $n$. Hadron-nucleus scattering is discussed.

   hep-phEPJC(2018)·2 citations
8. 08*

   Heating up Neutron Stars with Inelastic Dark Matter

   Nicole F. Bell🇦🇺 · Giorgio Busoni🇦🇺 · Sandra Robles🇦🇺

   Neutron stars can provide new insight into dark matter properties, as these dense objects capture dark matter particles very efficiently. It has recently been shown that the energy transfer in the dark matter capture process can lead to appreciable heating of neutron stars, which may be observable with forthcoming infra-red telescopes. We examine this heating in the context of inelastic dark matter, for which signals in conventional nuclear-recoil based direct detection experiments are highly suppressed when the momentum transfer is small compared to the mass splitting between dark matter states. Neutron stars permit inelastic scattering for much greater mass splittings, because dark matter particles are accelerated to velocities close to the speed of light during infall. Using an effective operator approach for fermionic DM that scatters inelastically, we show that the observation of a very cold neutron star would lead to very stringent limits on the interaction strengths that, in most cases, much stronger than any present, or future, direct detection experiment on Earth. This holds both for elastic scattering and for inelastic scattering with mass splittings up to $\sim 300MeV$.

   hep-phJCAP(2018)·148 citations
9. 09*

   Odderon and proton substructure from a model-independent Levy imaging of elastic $pp$ and $p\bar{p}$ collisions

   T. Csorgo🇭🇺 · R. Pasechnik🇸🇪 · A. Ster🇭🇺

   We describe a new and model-independent Lévy imaging method of quality fits to the published datasets and reconstruct the amplitude of high-energy $pp$ and $p\bar{p}$ elastic scattering processes. This method allows us to determine the excitation function of the shadow profile $P(b)$, the elastic slope $B(t)$ and the nuclear phase $\varphi (t)$ functions of $pp$ and $p\bar{p}$ collisions directly from the data. Surprisingly, notable qualitative differences in $B(t)$ for $pp$ and for $p\bar{p}$ collisions point towards an Odderon effect. As a by-product, we clearly identify the proton substructure with two different sizes at the ISR and LHC energies, that has striking similarity to a dressed quark (at the ISR) and a dressed diquark (at the LHC). We present model-independent results for the corresponding sizes and cross-sections for such a substructure for the existing data at different energies.

   hep-phhep-exnucl-exphysics.data-anEPJC(2019)·56 citations
10. 10*

    van der Waals hadron resonance gas and QCD phase diagram

    Nachiketa Sarkar🇮🇳 · Premomoy Ghosh🇮🇳

    Taking into account the recently developed van der Waals (VDW) like equation of state (EoS) for grand canonical ensemble of fermions, the temperature dependent profiles of normalized entropy density ($s/T^3$) and the ratio of shear viscosity and entropy density ($\eta /s$) for hadron resonance gas have been evaluated. The VDW parameters, corresponding to interactions between (anti)baryons, have been obtained by contrasting lattice EoS for QCD matter at finite chemical potentials (${\mu }_B$) and for $T\le$ 160 MeV. The temperature and chemical potential dependent study of $s/T^3$ and $\eta /s$ for hadron gas, by signalling onsets of first order phase transition and crossover in the hadronic phase of QCD matter, helps in understanding the QCD phase diagram in the ($T,{\mu }_B$) - plane. An estimation of probable location of critical point matches predictions from other recent studies.

    hep-phnucl-thPRC(2018)·29 citations
11. 11*

    A Model of Neutrino Mass, Baryon Asymmetry, and Asymmetric Dark Matter with $SU(2{)}_D\otimes U(1{)}_{D^{\prime }}$ Dark Sector

    Wei-Min Yang🇨🇳

    I suggest a new extension of the standard model of particle physics, which introduces a dark sector with the $SU(2{)}_D\otimes U(1{)}_{D^{\prime }}$ symmetry besides the SM sector. The new particles of the model all inhabit in the dark sector. The dark gauge symmetry breaking will bring about fruitful physics beyond the SM. The tiny neutrino mass is generated through the Dirac-type seesaw mechanism. The inflaton decay can not only provide the universe inflation and reheating, but also lead to the baryon asymmetry and the asymmetric cold dark matter. In short, the model provides an unification of the neutrino mass, the baryon asymmetry, the asymmetric CDM and the inflation, and it can account for their common origin. Finally, it is very possible to test the model predictions and probe the dark sector physics in near future experiments.

    hep-phNPB(2019)·4 citations
12. 12*

    Studies of Wick Cutkosky model in light of its classical ground state using Dyson Schwinger equations

    Tajdar Mufti🇵🇰

    Implications of additional fundamental scalar fields are regarded as among the most important avenues to explore after the experimental discovery of the standard model Higgs, particularly when there already exist cogent arguments in favor of their existence. A peculiar observation in Higgs-scalar singlet system is tendency of scalar singlet field to have negative squared physical masses which may be a sign of either a tachyon field or symmetry breaking. Assuming that this feature is due to the presence of a phenomenon similar to the conventionally understood Higgs mechanism, Wick Cutkosky model is studied in the parameter space suggested by the classical ground state of the system at Higgs mass $125.09$ GeV with positive values for both squared bare masses. The results are found to have strong negative contributions to squared scalar masses. For higher cutoff values, the renormalized squared scalar masses and squared bare couplings are found to qualitatively favor a relationship similar to the one in the classical ground state of the system, upto an additive constant. Higgs propagators remain almost unaffected as observed in a previously explored region of parameter space. However, scalar singlet propagators are found to have relatively different qualitative features in comparison to the previous study of the model. Vertices are found to have qualitatively similar features. No sign of triviality is found.

    hep-ph0 citations
13. 13*

    Weak decays of doubly heavy baryons: the FCNC processes

    Zhi-Peng Xing🇨🇳 · Zhen-Xing Zhao🇨🇳

    The discovery of doubly heavy baryon provides us with a new platform for precisely testing Standard Model and searching for new physics. As a continuation of our previous works, we investigate the FCNC processes of doubly heavy baryons. Light-front approach is adopted to extract the form factors, in which the two spectator quarks are viewed as a diquark. Results for form factors are then used to predict some phenomenological observables, such as the decay width and the forward-backward asymmetry. We find that most of the branching ratios for $b\to s$ processes are $10^{-8}\sim 10^{-7}$ and those for $b\to d$ processes are $10^{-9}\sim 10^{-8}$. The flavor SU(3) symmetry and symmetry breaking effects are explored. Parametric uncertainties are also investigated.

    hep-phhep-exPRD(2018)·51 citations
14. 14*

    Heavy-flavor flow-harmonics in high-energy nuclear collisions: time-development and eccentricity fluctuations

    A. Beraudo🇮🇹 · A. De Pace🇮🇹 · M. Monteno🇮🇹 · M. Nardi🇮🇹 · F. Prino🇮🇹

    We study the development of heavy-flavor flow harmonics in high-energy nuclear collisions. The elliptic and triangular flow of heavy-flavor hadrons, arising from the finite impact parameter of the two nuclei and from event-by-event fluctuations of the initial geometry, is analyzed in detail, considering the contribution from particles decoupling from the fireball at various times. We also study the dependence of the flow harmonics on the event-shape fluctuations, considering events belonging to the same centrality class but characterized by very different eccentricities (or vice-versa).

    hep-phnucl-exnucl-thNPA(2019)·5 citations
15. 15*

    Phenomenological bound on the viscosity of the hadron resonance gas

    Snigdha Ghosh🇮🇳 · Sabyasachi Ghosh🇮🇳 · Sumana Bhattacharyya🇮🇳

    We have explored some phenomenological issues during calculations of transport coefficients for hadronic matter, produced in the experiments of heavy ion collisions. Here, we have used an ideal hadron resonance gas model to demonstrate the issues. On the basis of dissipation mechanism, the hadronic zoo is classified into resonance and non-resonance members, who participate in dissipation via strong decay and scattering channels respectively. Imposing our phenomenological restriction, we are able to provide a rough upper and lower bound estimations of transport coefficients. Interestingly, we find that our proposed lower limit estimation for shear viscosity to entropy density ratio is little larger than its quantum lower bound. By taking a simple example, we have demonstrated how our proposed restriction help to tune any estimation of transport coefficients within its numerical band, proposed by us.

    hep-phnucl-thPRC(2018)·17 citations
16. 16*

    Hidden strange pentaquark in constituent quark models

    Xuejie Liu🇨🇳 · Hongxia Huang🇨🇳 · Jialun Ping🇨🇳

    In the framework of the chiral quark model, we investigate the hidden strange pentaquark system of the $N\varphi$ state with the quantum numbers of IJ=$\frac{1}{2}$$\frac{3}{2}$. The results show that the $N\varphi$ state can be bound through the interaction of the $\sigma$ meson exchange plus the effect of the channel coupling, which means that the effect of the channel coupling has an influence on the existence of this bound state.

    hep-phnucl-thPRC(2018)·11 citations
17. 17*

    Global fits of the MSSM with GAMBIT

    Anders Kvellestad (for the GAMBIT Collaboration)🇬🇧

    The minimal supersymmetric standard model is a popular and well-motivated extension of the standard model. As such, it has been constrained by a large number of different experimental searches. To truly assess the impacts of these experiments on the model one must perform a global fit, scanning over the multi-dimensional parameter space and combining all the data in a statistically rigorous manner. In this talk, I presented results from global fits of supersymmetric models performed with GAMBIT, the Global and Modular Beyond-the-Standard-Model (BSM) Inference Tool. I showed MSSM results from the latest GAMBIT papers, as well as exciting preliminary results from a dedicated study of the collider constraints on the electroweakino sector.

    hep-phPoS(2019)·4 citations
18. 18*

    A gauged horizontal $SU(2)$ symmetry and $R_{K^{(\ast )}}$

    Diego Guadagnoli🇫🇷 · Méril Reboud🇫🇷 · Olcyr Sumensari🇮🇹

    One of the greatest challenges for models of $b\to s$ anomalies is the necessity to produce a large contribution to a quark times a lepton current, $J_q\times J_{\ell }$, and to avoid accordingly large contributions to flavour-changing $J_q\times J_q$ and $J_{\ell }\times J_{\ell }$ amplitudes, which are severely constrained by data. We consider a gauged horizontal symmetry involving the two heaviest generations of all left-handed fermions. In the limit of degenerate masses for the horizontal bosons, and in the absence of mixing between the two heavier generations and the lighter one, such symmetry would make $J_q\times J_q$ and $J_{\ell }\times J_{\ell }$ amplitudes exactly flavour-diagonal. Mixing with the first generation is however inescapable due to the CKM matrix, and the above mechanism turns out to be challenged by constraints such as $D^0-{\bar{D}}^0$ mixing. Nonetheless, we show that a simultaneous description of all data can be accomplished by simply allowing for non-degenerate masses for the horizontal bosons. Such scenario predicts modifications in several processes that can be tested at present and upcoming facilities. In particular, it implies a lower and upper bound for $\mathcal{B}(B\to K{\mu }^{\pm }{\tau }^{\mp })$, an asymmetry between its two charge conjugated modes, and well-defined correlations with LFV in $\tau$ decays.

    hep-phJHEP(2018)·35 citations
19. 19*

    WIMPflation

    Dan Hooper🇺🇸 · Gordan Krnjaic🇺🇸 · Andrew J. Long🇺🇸 · Samuel D. McDermott🇺🇸

    We propose a class of models in which a stable inflaton is produced as a thermal relic in the early universe and constitutes the dark matter. We show that inflaton annihilations can efficiently reheat the universe, and identify several examples of inflationary potentials that can accommodate all cosmic microwave background observables and in which the inflaton dark matter candidate has a weak scale mass. As a simple example, we consider annihilations that take place through a Higgs portal interaction, leading to encouraging prospects for future direct detection experiments.

    hep-phastro-ph.COPRL(2019)·44 citations
20. 20*

    Leptogenesis from oscillations and dark matter

    Andrea Caputo🇪🇸 · Pilar Hernandez🇪🇸 · Nuria Rius🇪🇸

    An extension of the Standard Model with Majorana singlet fermions in the 1-100 GeV range can give rise to a baryon asymmetry at freeze-in via the CP-violating oscillations of these neutrinos: this is the well known ARS mechanism. In this paper we consider possible extensions of the minimal ARS scenario that can account not only for successful leptogenesis but also explain other open problems such as dark matter. We find that an extension in the form of a weakly coupled B-L gauge boson, an invisible QCD axion model, and the singlet majoron model can simultaneously account for dark matter and the baryon asymmetry.

    hep-phEPJC(2019)·28 citations
21. 21*

    Charged hadron fragmentation functions from collider data

    The NNPDF Collaboration: Valerio Bertone🇳🇱 · Nathan P. Hartland🇳🇱 · Emanuele R. Nocera🇬🇧 · Juan Rojo🇳🇱 · Luca Rottoli🇬🇧

    We present NNFF1.1h, a new determination of unidentified charged-hadron fragmentation functions (FFs) and their uncertainties. Experimental measurements of transverse-momentum distributions for charged-hadron production in proton-(anti)proton collisions at the Tevatron and at the LHC are used to constrain a set of FFs originally determined from electron-positron annihilation data. Our analysis is performed at next-to-leading order in perturbative quantum chromodynamics. We find that the hadron-collider data is consistent with the electron-positron data and that it significantly constrains the gluon FF. We verify the reliability of our results upon our choice of the kinematic cut in the hadron transverse momentum applied to the hadron-collider data and their consistency with NNFF1.0, our previous determination of the FFs of charged pions, kaons, and protons/antiprotons.

    hep-phhep-exEPJC(2018)·95 citations
22. 22*

    Spectral Analysis of Jet Substructure with Neural Networks: Boosted Higgs Case

    Sung Hak Lim🇯🇵 · Mihoko M. Nojiri🇯🇵

    Jets from boosted heavy particles have a typical angular scale which can be used to distinguish them from QCD jets. We introduce a machine learning strategy for jet substructure analysis using a spectral function on the angular scale. The angular spectrum allows us to scan energy deposits over the angle between a pair of particles in a highly visual way. We set up an artificial neural network (ANN) to find out characteristic shapes of the spectra of the jets from heavy particle decays. By taking the Higgs jets and QCD jets as examples, we show that the ANN of the angular spectrum input has similar performance to existing taggers. In addition, some improvement is seen when additional extra radiations occur. Notably, the new algorithm automatically combines the information of the multi-point correlations in the jet.

    hep-phhep-exstat.MLJHEP(2018)·28 citations
23. 23*

    Gamma rays from dark mediators in white dwarfs

    M. Cermeño🇪🇸 · M. Angeles Pérez-García🇪🇸

    We consider self-annihilation of dark matter, $\chi$, into metastable mediators, $Y$, and their subsequent decay into photons inside white dwarfs. We focus on reactions of the type $\chi \bar{\chi }\to YY$, where mediators, besides having a finite decay lifetime at rest ${\tau }_{\mathrm{rest}}\lesssim 1$ s, may suffer energy loss in the medium before they decay into photons, $Y\to \gamma \gamma$. We obtain attenuated gamma-ray luminosities arising from the combination of both effects. Using complementary sets of astrophysical measurements from cold white dwarfs in the M4 globular cluster as well as direct/indirect dark matter searches we discuss further constraints on dark mediator lifetimes.

    hep-phastro-ph.HEPRD(2018)·26 citations
24. 24*

    Analytic continuation of the kite family

    Christian Bogner🇩🇪 · Armin Schweitzer🇨🇭 · Stefan Weinzierl🇩🇪

    We consider results for the master integrals of the kite family, given in terms of ELi-functions which are power series in the nome $q$ of an elliptic curve. The analytic continuation of these results beyond the Euclidean region is reduced to the analytic continuation of the two period integrals which define $q.$ We discuss the solution to the latter problem from the perspective of the Picard-Lefschetz formula.

    ↳ hep-thhep-ph7 citations
25. 25*

    Going from Asymmetric Nuclei to Neutron Stars to Tidal Polarizability in Gravitational Waves

    Mannque Rho🇫🇷 · Yong-Liang Ma🇨🇳

    Among the five-year government-funded World Class University Projects in Korea, the category-3 program approved at Hanyang University in Seoul led to an exploratory effort to go from neutron-rich nuclei to dense matter in neutron stars. The principal results in what transpired in the effort -- and what followed afterwards -- are described with the focus on the possibly important, hitherto unexplored, role played in nuclear dynamics of topology and hidden symmetries of QCD. The potential link to the proton mass problem is pointed out.

    ↳ nucl-thastro-ph.SRhep-phIJMPE(2018)·3 citations
26. 26*

    DeepSource: Point Source Detection using Deep Learning

    A. Vafaei Sadr🇮🇷 · Etienne. E. Vos🇿🇦 · Bruce A. Bassett🇿🇦 · Zafiirah Hosenie🇿🇦 · N. Oozeer🇿🇦 · Michelle Lochner🇿🇦

    Point source detection at low signal-to-noise is challenging for astronomical surveys, particularly in radio interferometry images where the noise is correlated. Machine learning is a promising solution, allowing the development of algorithms tailored to specific telescope arrays and science cases. We present DeepSource - a deep learning solution - that uses convolutional neural networks to achieve these goals. DeepSource enhances the Signal-to-Noise Ratio (SNR) of the original map and then uses dynamic blob detection to detect sources. Trained and tested on two sets of 500 simulated 1 deg x 1 deg MeerKAT images with a total of 300,000 sources, DeepSource is essentially perfect in both purity and completeness down to SNR = 4 and outperforms PyBDSF in all metrics. For uniformly-weighted images it achieves a Purity x Completeness (PC) score at SNR = 3 of 0.73, compared to 0.31 for the best PyBDSF model. For natural-weighting we find a smaller improvement of ~40% in the PC score at SNR = 3. If instead we ask where either of the purity or completeness first drop to 90%, we find that DeepSource reaches this value at SNR = 3.6 compared to the 4.3 of PyBDSF (natural-weighting). A key advantage of DeepSource is that it can learn to optimally trade off purity and completeness for any science case under consideration. Our results show that deep learning is a promising approach to point source detection in astronomical images.

    ↳ astro-ph.IMcs.CVcs.LGhep-ph+1MNRAS(2019)·15 citations
27. 27*

    Causality and dissipation in relativistic polarizeable fluids

    David Montenegro🇧🇷 · Giorgio Torrieri🇧🇷

    We analyze the breakdown of causality for the perfect fluid limit in a medium with polarizeability. We show that to restore causality a relaxation term linking vorticity and polarization, analogous to the Israel-Stewart term linking viscous forces and gradients,is required. This term provides a minimum amount of dissipation a locally thermalized relativistic medium with polarizeability must have, independently of its underlying degrees of freedom. For ferromagnetic materials an infrared acausal mode remains, which we interpret as a Banks-Casher mode signaling spontaneous magnetization. With these ingredients, we propose a candidate for a fully causal Lagrangian of a relativistic polarizeable system near the perfect fluid limit.

    ↳ hep-thhep-phnucl-thPRD(2019)·102 citations
28. 28*

    Strong Bounds on Sum of Neutrino Masses in a 12 Parameter Extended Scenario with Non-Phantom Dynamical Dark Energy ($w(z)\ge -1$)

    Shouvik Roy Choudhury🇮🇳 · Abhishek Naskar🇮🇳

    We obtained constraints on a 12 parameter extended cosmological scenario including non-phantom dynamical dark energy (NPDDE) with CPL parametrization. We also include the six $\Lambda$CDM parameters, number of relativistic neutrino species ($N_{\text{eff}}$) and sum over active neutrino masses ($\sum m_{\nu }$), tensor-to-scalar ratio ($r_{0.05}$), and running of the spectral index ($n_{run}$). We use CMB Data from Planck 2015; BAO Measurements from SDSS BOSS DR12, MGS, and 6dFS; SNe Ia Luminosity Distance measurements from the Pantheon Sample; CMB B-mode polarization data from BICEP2/Keck collaboration (BK14); Planck lensing data; and a prior on Hubble constant ($73.24\pm 1.74$ km/sec/Mpc) from local measurements (HST). We have found strong bounds on the sum of the active neutrino masses. For instance, a strong bound of $\sum m_{\nu }<$ 0.123 eV (95\% C.L.) comes from Planck+BK14+BAO. Although we are in such an extended parameter space, this bound is stronger than a bound of $\sum m_{\nu }<$ 0.158 eV (95\% C.L.) obtained in $\Lambda \text{CDM}+\sum m_{\nu }$ with Planck+BAO. Varying $A_{\text{lens}}$ instead of $r_{0.05}$ however leads to weaker bounds on $\sum m_{\nu }$. Inclusion of the HST leads to the standard value of $N_{\text{eff}}=3.045$ being discarded at more than 68\% C.L., which increases to 95\% C.L. when we vary $A_{\text{lens}}$ instead of $r_{0.05}$, implying a small preference for dark radiation, driven by the $H_0$ tension.

    ↳ astro-ph.COhep-phEPJC(2019)·44 citations
29. 29*

    Asymptotic behavior of Nambu-Bethe-Salpeter wave functions for scalar systems with a bound state

    Shinya Gongyo🇯🇵 · Sinya Aoki🇯🇵

    We study the asymptotic behaviors of the Nambu-Bethe-Salpeter (NBS) wave functions, which are important for the HAL QCD potential method to extract hadron interactions, in the case that a bound state exists in the system. We consider the complex scalar particles, two of which lead to the formation of a bound state. In the case of the two-body system, we show that the NBS wave functions for the bound state as well as scattering states in the asymptotic region behave like the wave functions in quantum mechanics, which carry the information of the binding energy as well as the scattering phase shift. This analysis theoretically establishes under some conditions that the HAL QCD potential can correctly reproduce not only the scattering phase shift but also the binding energy. As an extension of the analysis, we also study the asymptotic behaviors of all possible NBS wave functions in the case of the three-body systems, two of which can form a bound states.

    ↳ hep-lathep-phnucl-thPTEP(2018)·8 citations
30. 30*

    USINE: semi-analytical models for Galactic cosmic-ray propagation

    D. Maurin🇫🇷

    I present the first public releases (v3.4 and v3.5) of the USINE code for cosmic-ray propagation in the Galaxy (https://lpsc.in2p3.fr/usine). It contains several semi-analytical propagation models previously used in the literature (leaky-box model, 2-zone 1D and 2D diffusion models) for the calculation of nuclei ($Z=1-30$), anti-protons, and anti-deuterons. For minimisations, the geometry, transport, and source parameters of all models can be enabled as free parameters, whereas nuisance parameters are enabled on solar modulation levels, cross sections (inelastic and production), and systematics of the CR data. With a single ASCII initialisation file to configure runs, its many displays, and the speed associated to semi-analytical approaches, USINE should be a useful tool for beginners, but also for experts to perform statistical analyses of high-precision cosmic-ray data.

    ↳ astro-ph.IMastro-ph.HEhep-phComput.Phys.Commun.(2020)·69 citations
31. 31*

    On the gallium experiment BEST-2 with a ${}^{65}$Zn source to search for neutrino oscillations on a short baseline

    V.N. Gavrin🇷🇺 · V.V. Gorbachev🇷🇺 · T.V. Ibragimova🇷🇺 · V.N. Kornoukhov🇷🇺 · A.A. Dzhanelidze🇷🇺 · S.B. Zlokazov🇷🇺 · N.A. Kotelnikov🇷🇺 · A.L. Izhutov🇷🇺 · S.V. Mainskov🇷🇺 · V.V. Pimenov🇷🇺 · V.P.Borisenko🇷🇺 · K.B. Kiselev🇷🇺 · M.P. Tsevelev🇷🇺

    In the paper is considered the use of a , ${}^{65}$Zn source in the BEST-2 gallium experiment to constrain the regions of the allowed oscillation parameters. The required activity of the ${}^{65}$Zn source for the BEST-2 experiment, its size, effect on the results of oscillatory measurements, as well as the possibility of production such a source are calculated. Schemes of measurements execution are considered.

    ↳ physics.ins-dethep-exhep-ph7 citations
32. 32*

    Voyager 1 $e^{\pm }$ Further Constrain Primordial Black Holes as Dark Matter

    Mathieu Boudaud🇫🇷 · Marco Cirelli🇫🇷

    Primordial Black Holes (PBHs) with a mass $M\lesssim 10^{17}$g are expected to inject sub-GeV electrons and positrons in the Galaxy via Hawking radiation. These cosmic rays are shielded by the solar magnetic field for Earth-bound detectors, but not for Voyager-1, which is now beyond the heliopause. We use its data to constrain the fraction of PBHs to the dark matter in the Galaxy, finding that PBHs with $M<10^{16}$g cannot contribute more than 0.1% (or less for a lognormal mass distribution). Our limits are based on local galactic measurements and are thus complementary to those derived from cosmological observations.

    ↳ astro-ph.HEastro-ph.COhep-phPRL(2019)·257 citations
33. 33*

    TASI Lectures on Primordial Cosmology

    Daniel Baumann🇳🇱

    These lectures cover aspects of primordial cosmology with a focus on observational tests of physics beyond the Standard Model. The presentation is divided into two parts: In Part I, we study the production of new light particles in the hot big bang and describe their effects on the anisotropies of the cosmic microwave background. In Part II, we investigate the possibility of very massive particles being created during inflation and determine their imprints in higher-order cosmological correlations.

    ↳ hep-thastro-ph.COhep-phPoS(2018)·193 citations
34. 34*

    On strangeness in NA61/SHINE

    Maciej P. Lewicki (for the NA61/SHINE Collaboration)🇵🇱

    NA61/SHINE is a fixed target experiment at the CERN Super-Proton- Synchrotron. The main goals of the experiment are to discover the critical point of strongly interacting matter and to study the properties of the onset of deconfinement. In order to reach these goals, a study of hadron production properties is performed in nucleus-nucleus, proton-proton and proton-nucleus interactions as a function of collision energy and size of the colliding nuclei. In this paper, I will review recent results on strangeness production in p+p, Be+Be and Ar+Sc collisions in the SPS energy range. Kinematic spectra and mean multiplicities of kaons obtained with various analysis methods will be shown. An overview of strangeness production and its dependence on system size in the vicinity of the phase transition will be presented as well.

    ↳ hep-exhep-phnucl-exnucl-thActa Phys.Polon.Supp.(2018)·2 citations
35. 35*

    A mixing interpolation method to mimic pasta phases in compact star matter

    David Blaschke🇵🇱 · David Alvarez-Castillo🇷🇺

    We present a new method to interpolate between two matter phases that allows for a description of mixed phases and can be used, e.g., for mimicking transitions between pasta structures occuring in the crust as well as in the inner core of compact stars. This interpolation method is based on assuming switch functions that are used to define a mixture of subphases while fulfilling constraints of thermodynamic stability. The width of the transition depends on a free parameter, the pressure increment relative to the critical pressure of a Maxwell construction. As an example we present a trigonometric function ansatz for the switch function together with a pressure increment during the transition. We note that the resulting mixed phase equation of state bears similarities with the appearance of substitutional compounds in neutron star crusts and with the sequence of transitions between different pasta phases in the hadron-to-quark matter transition. We apply this method to the case of a hadron-to-quark matter transition and test the robustness of the compact star mass twin phenomenon against the appearance of pasta phases modeled in this way.

    ↳ nucl-thastro-ph.HEhep-phEPJA(2020)·15 citations
36. 36*

    Super-Knee Cosmic Rays from Galactic Neutron Star Merger Remnants

    Shigeo S. Kimura🇺🇸 · Kohta Murase🇺🇸 · Peter Mészáros🇺🇸

    The detection of gravitational waves and electromagnetic counterparts from a binary neutron star (BNS) merger confirmed that it is accompanied by the launch of fast merger ejecta. Analogous to supernova remnants, forward shocks formed by the interaction of the ejecta with interstellar material will produce high-energy cosmic rays. We investigate the possibility that Galactic neutron star merger remnants (NSMRs) significantly contribute to the observed cosmic rays in the energy range between the knee and the ankle. Using typical parameters obtained by modeling of GW170817, we find that NSMRs can accelerate iron nuclei up to $\sim 500$ PeV. We calculate the cosmic-ray spectrum and composition observed on Earth, and show that the Galactic NSMR scenario can account for the experimental cosmic-ray data in the 20 -- 1000 PeV range. Our model can naturally explain the hardening feature around 20 PeV for total cosmic-ray spectrum, which has been observed by the Telescope Array Low Energy extension and the IceTop air shower array.

    ↳ astro-ph.HEhep-phnucl-thApJ(2018)·34 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.