Wed·Mar 21, 2018Wednesday·March 21, 2018

1. 01*

   Soft Pomerons and the Forward LHC Data

   M. Broilo🇧🇷 · E.G.S. Luna🇧🇷 · M.J. Menon🇧🇷

   Recent data from LHC13 by the TOTEM Collaboration on ${\sigma }_{tot}$ and $\rho$ have indicated disagreement with all the Pomeron model predictions by the COMPETE Collaboration (2002). On the other hand, as recently demonstrated by Martynov and Nicolescu (MN), the new ${\sigma }_{tot}$ datum and the unexpected decrease in the $\rho$ value are well described by the maximal Odderon dominance at the highest energies. Here, we discuss the applicability of Pomeron dominance through fits to the \textit{most complete set} of forward data from $pp$ and $\bar{p}p$ scattering. We consider an analytic parametrization for ${\sigma }_{tot}(s)$ consisting of non-degenerated Regge trajectories for even and odd amplitudes (as in the MN analysis) and two Pomeron components associated with double and triple poles in the complex angular momentum plane. The $\rho$ parameter is analytically determined by means of dispersion relations. We carry out fits to $pp$ and $\bar{p}p$ data on ${\sigma }_{tot}$ and $\rho$ in the interval 5 GeV - 13 TeV (as in the MN analysis). Two novel aspects of our analysis are: (1) the dataset comprises all the accelerator data below 7 TeV and we consider \textit{three independent ensembles} by adding: either only the TOTEM data (as in the MN analysis), or only the ATLAS data, or both sets; (2) in the data reductions to each ensemble, uncertainty regions are evaluated through error propagation from the fit parameters, with 90 \% CL. We argument that, within the uncertainties, this analytic model corresponding to soft Pomeron dominance, does not seem to be excluded by the \textit{complete} set of experimental data presently available.

   hep-phhep-exPLB(2018)·32 citations
2. 02*

   A development of an accelerator board dedicated for multi-precision arithmetic operations and its application to Feynman loop integrals II

   H Daisaka🇯🇵 · N Nakasato🇯🇵 · T Ishikawa🇯🇵 · F Yuasa🇯🇵 · K Nitadori🇯🇵

   Evaluation of a wide variety of Feynman diagrams with multi-loop integrals and physical parameters and its comparison with high energy experiments are expected to investigate new physics beyond the Standard Model. We have been developing a direct computation method of multi-loop integrals of Feynman diagrams. One of features of our method is that we adopt the double exponential rule for numerical integrations which enables us to evaluate loop integrals with boundary singularities. Another feature is that in order to accelerate the numerical integrations with multi-precision calculations, we develop an accelerator system with Field Programmable Gate Array boards on which processing elements with dedicated logic for quadruple/hexuple/octuple precision arithmetic operations are implemented. In addition, we also develop a programming interface designed for easy use of the system. The development is continued for practical use of the system. We present the current development of our system, and the numerical results of higher-loop diagrams performed using our system.

   hep-phphysics.comp-phJ.Phys.Conf.Ser.(2018)·0 citations
3. 03*

   Status of quarkonia - like negative and positive parity states in a relativistic confinement scheme

   Tanvi Bhavsar🇮🇳 · Manan Shah🇮🇳 · P C Vinodkumar🇮🇳

   Properties of quarkonia - like states in the charm and bottom sector have been studied in the frame work of relativistic Dirac formalism with a linear confinement potential. We have computed the mass spectroscopy and decay properties (vector decay constant and leptonic decay width) of several quarkonia - like states. Present study is also intended to identify some of the unexplained states as mixed P-wave and mixed S-D wave states of Charmonia and Bottomonia. The results indicate that the X(4140) state can be an admixture of two P states of charmonium. And the charmonium like states X(4630) and X(4660) are the admixed state of S - D waves. Similarly, the $X(10610)$ state recently reported by Belle II can be a mixed P - states of bottomonium. In the relativistic framework we have computed vector decay constant and the leptonic decay width for S wave charmonium and bottomonium. The leptonic decay width for the $J^{PC}=1^{--}$ mixed states are also predicted. Further, both the masses and the leptonic decay width are considered for the identification of the quarkonia-like states.

   hep-phEPJC(2018)·38 citations
4. 04*

   Does the chiral magnetic effect change the dynamic universality class in QCD?

   Masaru Hongo🇯🇵 · Noriyuki Sogabe🇯🇵 · Naoki Yamamoto🇯🇵

   In QCD matter under an external magnetic field, the chiral magnetic effect (CME) leads to the collective gapless mode called the chiral magnetic wave (CMW). Since dynamic universality class generally depends on low-energy gapless modes, it is nontrivial whether the CME and the resulting CMW change that of the second-order chiral phase transition in QCD. To address this question, we study the critical dynamics near the chiral phase transition in massless two-flavor QCD under an external magnetic field. By performing the dynamic renormalization-group analysis within the epsilon expansion, we find that the presence of the CME changes the dynamic universality class to that of model A. We also show that the transport coefficient of the CME is not renormalized by the critical fluctuations of the order parameter.

   hep-phcond-mat.mes-hallcond-mat.stat-mechnucl-thJHEP(2018)·6 citations
5. 05*

   Dynamical Gauge Boson of Hidden Local Symmetry within the Standard Model

   Koichi Yamawaki🇯🇵

   The Standard Model (SM) Higgs Lagrangian is straightforwardly rewritten into the {\it scale-invariant} nonlinear sigma model $G/H=[SU(2{)}_L\times SU(2{)}_R]/SU(2{)}_V\simeq O(4)/O(3)$, with the (approximate) scale symmetry realized nonlinearly by the (pseudo) dilaton ($=$ SM Higgs). It is further gauge equivalent to that having the symmetry $O(4{)}_{\mathrm{global}}\times O(3{)}_{\mathrm{local}}$, with $O(3{)}_{\mathrm{local}}$ being the Hidden Local Symmetry (HLS). In the large $N$ limit of the scale-invariant version of the Grassmannian model $G/H=O(N)/[O(N-3)\times O(3)]$ $\simeq O(N{)}_{\mathrm{global}}\times [O(N-3)\times O(3){]}_{\mathrm{local}}$, identical to the SM for $N\to 4$, we show that the kinetic term of the HLS gauge bosons ("SM rho") ${\rho }_{\mu }$ of the $O(3{)}_{\mathrm{local}}\simeq [SU(2{)}_V{]}_{\mathrm{local}}$ are dynamically generated by the nonperturbative dynamics of the SM itself. The dynamical SM rho stabilizes the skyrmion ("SM skyrmion") $X_s$ as a dark matter candidate within the SM: The mass $M_{X_s}=\mathcal{O}(10\mathrm{GeV})$ consistent with the direct search experiments implies the induced HLS gauge coupling $g_{{}_{\mathrm{HLS}}}=\mathcal{O}(10^3)$, which realizes the relic abundance, ${\Omega }_{X_s}{h}^2=\mathcal{O}(0.1)$. If instead $g_{{}_{\mathrm{HLS}}}\lesssim 3.5$ ($M_{\rho }\lesssim 1.2$ TeV), the SM rho could be detected with "narrow width" $\lesssim 100\mathrm{GeV}$ at LHC, having all the "$a=2$ results" of the generic HLS Lagrangian ${\mathcal{L}}_A+a{\mathcal{L}}_V$, i.e., $\rho$-universality, KSRF relations and the vector meson dominance, independently of "$a$". There exists the second order phase phase transition to the unbroken phase having massless ${\rho }_{\mu }$ and massive $\pi$ (no longer NG bosons), both becoming massless free particles just on the transition point (scale-invariant ultraviolet fixed point).The results readily apply to the 2-flavored QCD as well.

   hep-phhep-thnucl-th10 citations
6. 06*

   Updated study of the $\eta$-${\eta }^{\prime }$ mixing and the thermal properties of light pseudoscalar mesons at low temperatures

   Xiao-Wei Gu🇨🇳 · Chun-Gui Duan🇨🇳 · Zhi-Hui Guo🇨🇳

   Within the framework of the $U(3)$ chiral perturbation theory, we revisit the masses, decay constants and the mixing parameters of the light pseudoscalar mesons $\pi ,K,\eta$ and ${\eta }^{\prime }$. The low energy constants up to next-to-next-to-leading order are determined by including the light-quark mass dependences of the various quantities from different lattice QCD simulations and relevant phenomenological inputs. Then we study the finite-temperature behaviors of the masses of the light pseudoscalar mesons. The thermal behaviors of the $\eta$-${\eta }^{\prime }$ mixing angles in singlet-octet and quark-flavor bases are also explored. While the masses of the $\pi ,K$, and $\eta$ are increased when increasing the temperatures, the mass of the ${\eta }^{\prime }$ turns out to be slightly decreased in the low-temperature region.

   hep-phPRD(2018)·28 citations
7. 07*

   Simulations of Cold Electroweak Baryogenesis: Dependence on the source of CP-violation

   Zong-Gang Mou🇳🇴 · Paul M. Saffin🇬🇧 · Anders Tranberg🇳🇴

   We compute the baryon asymmetry created in a tachyonic electroweak symmetry breaking transition, focusing on the dependence on the source of effective CP-violation. Earlier simulations of Cold Electroweak Baryogenesis have almost exclusively considered a very specific CP-violating term explicitly biasing Chern-Simons number. We compare four different dimension six, scalar-gauge CP-violating terms, involving both the Higgs field and another dynamical scalar coupled to SU(2) or U(1) gauge fields. We find that for sensible values of parameters, all implementations can generate a baryon asymmetry consistent with observations, showing that baryogenesis is a generic outcome of a fast tachyonic electroweak transition.

   hep-phhep-lathep-thJHEP(2018)·4 citations
8. 08*

   Muon anomalies and the $SU(5)$ Yukawa relations

   A. E. Cárcamo Hernández🇨🇱 · Stephen F. King🇬🇧

   We show that, within the framework of $SU(5)$ Grand Unified Theories (GUTs), multiple vector-like families at the GUT scale which transform under a gauged $U(1{)}^{\prime }$ (under which the three chiral families are neutral) can result in a single vector-like family at low energies which can induce non-universal and flavourful $Z^{\prime }$ couplings, which can account for the B physics anomalies in $R_{K^{(\ast )}}$. In such theories, we show that the same muon couplings which explain $R_{K^{(\ast )}}$ also correct the Yukawa relation $Y_e=Y_d^T$ in the muon sector without the need for higher Higgs representations. To illustrate the mechanism, we construct a concrete a model based on $SU(5)\times A_4\times Z_3\times Z_7$ with two vector-like families at the GUT scale, and two right-handed neutrinos, leading to a successful fit to quark and lepton (including neutrino) masses, mixing angles and CP phases, where the constraints from lepton flavour violation require $Y_e$ to be diagonal.

   hep-phPRD(2019)·27 citations
9. 09*

   Dark Matter and The Seesaw Scale

   Pavel Fileviez Perez🇺🇸 · Clara Murgui🇪🇸

   We discuss the possibility to find an upper bound on the seesaw scale using the cosmological bound on the cold dark matter relic density. We investigate a simple relation between the origin of neutrino masses and the properties of a dark matter candidate in a simple theory where the new symmetry breaking scale defines the seesaw scale. Imposing the cosmological bounds, we find an upper bound of order multi-TeV on the lepton number violation scale. We investigate the predictions for direct and indirect detection dark matter experiments, and the possible signatures at the Large Hadron Collider.

   hep-phhep-exPRD(2018)·12 citations
10. 10*

    Identifying a $Z^{\prime }$ behind $b\to s\ell \ell$ anomalies at the LHC

    Masaya Kohda🇹🇼 · Tanmoy Modak🇹🇼 · Abner Soffer🇮🇱

    Recent $b\to s\ell \ell$ anomalies may imply the existence of a new $Z^{\prime }$ boson with left-handed $Z^{\prime }bs$ and $Z^{\prime }\mu \mu$ couplings. Such a $Z^{\prime }$ may be directly observed at LHC via $b\bar{s}\to Z^{\prime }\to {\mu }^{+}{\mu }^{-}$, and its relevance to $b\to s\ell \ell$ may be studied by searching for the process $gs\to Z^{\prime }b\to {\mu }^{+}{\mu }^{-}b$. In this paper, we analyze the capability of the 14 TeV LHC to observe the $Z^{\prime }$ in the ${\mu }^{+}{\mu }^{-}$ and ${\mu }^{+}{\mu }^{-}b$ modes based on an effective model with major phenomenological constraints imposed. We find that both modes can be discovered with 3000 fb${}^{-1}$ data if the $Z^{\prime }bs$ coupling saturates the latest $B_s-{\bar{B}}_s$ mixing limit from UTfit at around $2\sigma$. Besides, a tiny right-handed $Z^{\prime }bs$ coupling, if it exists, opens up the possibility of a relatively large left-handed counterpart, due to cancellation in the $B_s-{\bar{B}}_s$ mixing amplitude. In this case, we show that even a data sample of $\mathcal{O}(100)$ fb${}^{-1}$ would enable discovery of both modes. We further study the impact of a $Z^{\prime }bb$ coupling as large as the $Z^{\prime }bs$ coupling. This scenario enables discovery of the $Z^{\prime }$ in both modes with milder effects on the $B_s-{\bar{B}}_s$ mixing, but obscures the relevance of the $Z^{\prime }$ to $b\to s\ell \ell$. Discrimination between the $Z^{\prime }bs$ and $Z^{\prime }bb$ couplings may come from the production cross section for the $Z^{\prime }b\bar{b}$ final state. However, we do not find the prospect for this to be promising.

    hep-phhep-exPRD(2018)·29 citations
11. 11*

    Influence of the $Z-Z^{\prime }$ mixing on the $Z^{\prime }$ production cross section in the model-independent approach

    A. Pevzner🇺🇦

    The new module SMZp is developed for the Monte-Carlo generator Sherpa that extends simulations of the Standard model (SM) processes with the Abelian $Z^{\prime }$ boson in the model-independent approach. The special derived earlier relations between the $Z^{\prime }$ couplings to the SM fields proper to the renormalizable theories are taken into account. Using this module, dependence of the $Z^{\prime }$ production cross section on the $Z-Z^{\prime }$ mixing angle ${\theta }_0$ in the Drell-Yan process is investigated within the range of 1 TeV $\le m_{Z^{\prime }}\le$ 5 TeV. It is shown that if it is essential to keep the $Z^{\prime }$ theory renormalizable, ${\theta }_0$ cannot be neglected as it is often done, even if it is small.

    hep-phNonlin.Phenom.Complex Syst.(2018)·0 citations
12. 12*

    Hidden strongly interacting massive particles

    Matti Heikinheimo🇫🇮 · Kasper Langaeble🇩🇰 · Kimmo Tuominen🇫🇮

    We consider dark matter as Strongly Interacting Massive Particles (SIMPs) in a hidden sector, thermally decoupled from the Standard Model heat bath. Due to its strong interactions, the number-changing processes of the SIMP lead to its thermalization at temperature $T_{\mathrm{D}}$ different from the visible sector temperature $T$, and subsequent decoupling as the Universe expands. We study the evolution of the dark SIMP abundance in detail and find that a hidden SIMP provides for a consistent framework for self-interacting dark matter. Thermalization and decoupling of a composite SIMP can be treated within the domain of validity of chiral perturbation theory unlike the simplest realizations of the SIMP, where the SIMP is in thermal equilibrium with the Standard Model.

    hep-phPRD(2018)·28 citations
13. 13*

    Model-independent constraints on the Abelian $Z^{\prime }$ couplings within the ATLAS data on the dilepton production processes at $\sqrt{s}=$ 13 TeV

    A. Gulov🇺🇦 · A. Pankov🇧🇾 · A. Pevzner🇺🇦 · V. Skalozub🇺🇦

    The study of lepton pair production is a powerful test of the Standard Model (SM) and can be used to search for phenomena beyond the SM. New heavy neutral bosons $Z^{\prime }$ decaying to charged lepton pairs $l^{+}{l}^{-}$ ($l=e,\mu$) are predicted by many scenarios of new physics, including models with extended gauge sector. We estimate the LHC $Z^{\prime }$ discovery potential with Run 2 data comprised of 36.1 fb${}^{-1}$ of $pp$ collisions at $\sqrt{s}=13$ TeV and recorded by ATLAS detector at the CERN LHC. The model-independent constraints on the $Z^{\prime }$ fermion couplings were obtained for the first time for a selected set of $Z^{\prime }$ signal mass points of $M_{Z^{\prime }}=2$, 3, and 4 TeV by using the ATLAS data collected at the LHC. The analysis is based on the derived earlier special relations between the $Z^{\prime }$ couplings proper to the renormalizable theories. Taking into account the dependence of $Z-Z^{\prime }$ mixing angle ${\theta }_0$ on the $Z^{\prime }$ axial-vector coupling $a$, the limits on ${\theta }_0$ are established as ${\theta }_0<10^{-4}-10^{-3}$ in the investigated $Z^{\prime }$ mass range.

    hep-phNonlin.Phenom.Complex Syst.(2018)·7 citations
14. 14*

    NLO PDFs from the ABMP16 fit

    S. Alekhin🇩🇪 · J. Blümlein🇩🇪 · S. Moch🇩🇪

    We perform a global fit of parton distribution functions (PDFs) together with the strong coupling constant ${\alpha }_s$ and the quark masses $m_c$, $m_b$ and $m_t$ at next-to-leading order (NLO) in QCD. The analysis applies the $\overline{\mathrm{MS}}$ renormalization scheme for ${\alpha }_s$ and all quark masses. It is performed in the fixed-flavor number scheme for $n_f=3,4,5$ and uses the same data as the previous fit of the ABMP16 PDF at next-to-next-to-leading order (NNLO). The new NLO PDFs complement the set of ABMP16 PDFs and are to be used consistently with NLO QCD predictions for hard scattering processes. At NLO we obtain the value ${\alpha }_s^{(n_f=5)}(M_Z)=0.1191\pm 0.0011$ compared to ${\alpha }_s^{(n_f=5)}(M_Z)=0.1147\pm 0.0008$ at NNLO.

    hep-phEPJC(2018)·113 citations
15. 15*

    Light axions with large hadronic couplings

    Gustavo Marques-Tavares🇺🇸 · Mae Teo🇺🇸

    We present models in which axions have large couplings to hadrons while remaining naturally light. By assigning $U(1{)}_{PQ}$ charges to Standard Model quarks such that $U(1{)}_{PQ}$ is not anomalous under QCD, the derivative couplings naturally arise while no potential is generated for the axion upon QCD confinement. We present simple models that implement this idea both for an axion-like particle and for the QCD axion. We show that both models lead to sizable flavor violations that could be probed by future experiments. Our construction shows that the axion coupling to hadrons can be essentially independent from its mass and thus motivates experimental searches in a wide range of axion parameter space.

    hep-phJHEP(2018)·17 citations
16. 16*

    A Cosmological Solution to the Impossibly Early Galaxy Problem

    Manoj K. Yennapureddy🇺🇸 · Fulvio Melia🇺🇸

    To understand the formation and evolution of galaxies at redshifts z < 10, one must invariably introduce specific models (e.g., for the star formation) in order to fully interpret the data. Unfortunately, this tends to render the analysis compliant to the theory and its assumptions, so consensus is still somewhat elusive. Nonetheless, the surprisingly early appearance of massive galaxies challenges the standard model, and the halo mass function estimated from galaxy surveys at z > 4 appears to be inconsistent with the predictions of LCDM, giving rise to what has been termed "The Impossibly Early Galaxy Problem" by some workers in the field. A simple resolution to this question may not be forthcoming. The situation with the halos themselves, however, is more straightforward and, in this paper, we use linear perturbation theory to derive the halo mass function over the redshift range z < 10 for the R_h=ct universe. We use this predicted halo distribution to demonstrate that both its dependence on mass and its very weak dependence on redshift are compatible with the data. The difficulties with LCDM may eventually be overcome with refinements to the underlying theory of star formation and galaxy evolution within the halos. For now, however, we demonstrate that the unexpected early formation of structure may also simply be due to an incorrect choice of the cosmology, rather than to yet unknown astrophysical issues associated with the condensation of mass fluctuations and subsequent galaxy formation.

    ↳ astro-ph.COastro-ph.GAgr-qchep-phPhys.Dark Univ.(2018)·11 citations
17. 17*

    Reheating through the Higgs amplified by spinodal instabilities and gravitational creation of gravitons

    Tomohiro Nakama🇺🇸 · Jun'ichi Yokoyama🇯🇵

    It is shown that a positive non-minimal coupling of the Higgs field to gravity can solve the two problems in inflation models in which postinflationary universe is dominated by an energy with stiff equation of state such as a kination, namely, overproduction of gravitons in gravitational reheating scenario, and overproduction of curvature perturbation from Higgs condensation. Furthermore, we argue that the non-minimal coupling parameter can be constrained more stringently with the progress in observations of large-scale structure and cosmic microwave background.

    ↳ gr-qcastro-ph.COhep-phPTEP(2019)·32 citations
18. 18*

    Novel $|V_{us}|$ Determination Using Inclusive Strange $\tau$ Decay and Lattice HVPs

    Peter Boyle🇬🇧 · Renwick James Hudspith🇨🇦 · Taku Izubuchi🇺🇸 · Andreas Jüttner🇬🇧 · Christoph Lehner🇺🇸 · Randy Lewis🇨🇦 · Kim Maltman🇨🇦 · Hiroshi Ohki🇺🇸 · Antonin Portelli🇬🇧 · Matthew Spraggs🇬🇧

    We propose and apply a new approach to determining $|V_{us}|$ using dispersion relations with weight functions having poles at Euclidean (space-like) momentum which relate strange hadronic $\tau$ decay distributions to hadronic vacuum polarization functions (HVPs) obtained from lattice QCD. We show examples where spectral integral contributions from the region where experimental data have large errors or do not exist are strongly suppressed but accurate determinations of the relevant lattice HVP combinations remain possible. The resulting $|V_{us}|$ agrees well with determinations from $K$ physics and 3-family CKM unitarity. Advantages of this new approach over the conventional hadronic $\tau$ decay determination employing flavor-breaking sum rules are also discussed.

    ↳ hep-lathep-phPRL(2018)·35 citations
19. 19*

    Robust Limits on Photon Mass from Statistical Samples of Extragalactic Radio Pulsars

    Jun-Jie Wei🇨🇳 · Xue-Feng Wu🇨🇳

    The photon zero-mass hypothesis has been investigated for a long time using the frequency-dependent time delays of radio emissions from astrophysical sources. However, the search for a rest mass of the photon has been hindered by the similarity between the frequency-dependent dispersions due to the plasma and nonzero photon mass effects. Considering the contributions to the observed dispersion measure from both the plasma and nonzero photon mass effects, and assuming the dispersion induced by the plasma effect is an unknown constant, we obtain a robust limit on the photon mass by directly fitting a combination of the dispersion measures of radio sources. Using the observed dispersion measures from two statistical samples of extragalactic pulsars, here we show that at the 68\% confidence level, the constraints on the photon mass can be as low as $m_{\gamma }\le 1.51\times 10^{-48}\mathrm{kg}\simeq 8.47\times 10^{-13}\mathrm{eV}/{\mathrm{c}}^2$ for the sample of 22 radio pulsars in the Large Magellanic Cloud and $m_{\gamma }\le 1.58\times 10^{-48}\mathrm{kg}\simeq 8.86\times 10^{-13}\mathrm{eV}/{\mathrm{c}}^2$ for the other sample of 5 radio pulsars in the Small Magellanic Cloud, which are comparable with that obtained by a single extragalactic pulsar. Furthermore, the statistical approach presented here can also be used when more fast radio bursts with known redshifts are detected in the future.

    ↳ astro-ph.HEastro-ph.COgr-qchep-phJCAP(2018)·29 citations
20. 20*

    The $H_0$ Tension in Non-flat QCDM Cosmology

    Haitao Miao🇨🇳 · Zhiqi Huang🇨🇳

    The recent local measurement of Hubble constant leads to a more than $3\sigma$ tension with Planck + $\Lambda$CDM (Riess {\it et al} 2018). In this article we study the $H_0$ tension in non-flat QCDM cosmology, where Q stands for a minimally coupled and slowly-or-moderately rolling quintessence field $\varphi$ with a smooth potential $V(\varphi )$. By generalizing the QCDM one-parameter and three-parameter parametrizations in Huang {\it et al} 2011 to non-flat universe and using the latest cosmological data, we find that the $H_0$ tension remains above $3.2\sigma$ level for this class of model.

    ↳ astro-ph.COgr-qchep-phApJ(2018)·33 citations
21. 21*

    Non-minimal gravitational reheating during kination

    Konstantinos Dimopoulos🇬🇧 · Tommi Markkanen🇬🇧

    A new mechanism is presented which can reheat the Universe in non-oscillatory models of inflation, where the inflation period is followed by a period dominated by the kinetic density for the inflaton field (kination). The mechanism considers an auxiliary field non-minimally coupled to gravity. The auxiliary field is a spectator during inflation, rendered heavy by the non-minimal coupling to gravity. During kination however, the non-minimal coupling generates a tachyonic mass, which displaces the field, until its bare mass becomes important, leading to coherent oscillations. Then, the field decays into the radiation bath of the hot big bang. The model is generic and predictive, in that the resulting reheating temperature is a function only of the model parameters (masses and couplings) and not of initial conditions. It is shown that reheating can be very efficient also when considering only the Standard Model.

    ↳ gr-qcastro-ph.COhep-phJCAP(2018)·106 citations
22. 22*

    Multipole vectors of completely random microwave skies for $l\le 50$

    Marvin Pinkwart🇩🇪 · Dominik J. Schwarz🇩🇪

    The statistical cosmological principle states that observables on the celestial sphere are sampled from a rotationally invariant distribution. Previously certain large scale anomalies which violate this principle have been found, for example an alignment of the lowest multipoles with the cosmic dipole direction. In this work we continue the search for possible anomalies using multipole vectors which represent a convenient tool for this purpose. In order to study the statistical behavior of multipole vectors, we revisit several construction methods. We investigate all four full-sky foreground-cleaned maps from the Planck 2015 release with respect to four meaningful physical directions using computationally cheap statistics that have a simple geometric interpretation. We find that the full-sky SEVEM map deviates from all the other cleaned maps, as it shows a strong correlation with the Galactic Pole and Galactic Center. The other three maps COMMANDER, NILC and SMICA show a consistent behavior. On the largest angular scales, $l\le 5$, as well as on intermediate scales, $l=20,21,22,23,24$, all of them are unusually correlated with the cosmic dipole direction. These scales coincide with the scales on which the angular power spectrum deviates from the Planck 2015 best-fit {\Lambda}CDM model. In the range $2\le l\le 50$ as a whole there is no unusual behavior visible globally. We do not find abnormal intramultipole correlation, i.e. correlation of multipole vectors inside a given multipole without reference to any outer direction.

    ↳ astro-ph.COgr-qchep-phPRD(2018)·11 citations
23. 23*

    Neutrinos from Choked Jets Accompanied by Type-II Supernovae

    Hao-Ning He🇨🇳 · Alexander Kusenko🇺🇸 · Shigehiro Nagataki🇯🇵 · Yi-Zhong Fan🇨🇳 · Da-Ming Wei🇨🇳

    The origin of the IceCube neutrinos is still an open question. Upper limits from diffuse gamma-ray observations suggest that the neutrino sources are either distant or hidden from gamma-ray observations. It is possible that the neutrinos are produced in jets that are formed in the core-collapsing massive stars and fail to break out, the so-called choked jets. We study neutrinos from the jets choked in the hydrogen envelopes of red supergiant stars. Fast photo-meson cooling softens the neutrino spectrum, making it difficult to explain the PeV neutrinos observed by IceCube in a one-component scenario, but a two-component model can explain the spectrum. Furthermore, we predict that a newly born jet-driven type-II supernova may be observed to be associated with a neutrino burst detected by IceCube.

    ↳ astro-ph.HEhep-phApJ(2018)·52 citations
24. 24*

    Void Lensing as a Test of Gravity

    Tessa Baker🇬🇧 · Joseph Clampitt🇺🇸 · Bhuvnesh Jain🇺🇸 · Mark Trodden🇺🇸

    We investigate the potential of weak lensing by voids to test for deviations from General Relativity. We calculate the expected lensing signal of a scalar field with derivative couplings, finding that it has the potential to boost the tangential shear both within and outside the void radius. We use voids traced by Luminous Red Galaxies in SDSS to demonstrate the methodology of testing these predictions. We find that the void central density parameter, as inferred from the lensing signal, can shift from its GR value by up to 20% in some galileon gravity models. Since this parameter can be estimated independently using the galaxy tracer profiles of voids, our method provides a consistency check of the gravity theory. Although galileon gravity is now disfavoured as a source of cosmic acceleration by other datasets, the methods we demonstrate here can be used to test for more general fifth force effects with upcoming void lensing data.

    ↳ astro-ph.COgr-qchep-phPRD(2018)·71 citations
25. 25*

    Neutrino masses and beyond-$\Lambda$CDM cosmology with LSST and future CMB experiments

    Siddharth Mishra-Sharma🇺🇸 · David Alonso🇬🇧 · Joanna Dunkley🇺🇸

    Cosmological measurements over the next decade will enable us to shed light on the content and evolution of the Universe. Complementary measurements of the Cosmic Microwave Background (CMB) and Baryon Acoustic Oscillations are expected to allow an indirect determination of the sum of neutrino masses, within the framework of the flat $\Lambda$CDM model. However, possible deviations from $\Lambda$CDM such as a non-zero cosmological curvature or a dark energy equation of state with $w\ne -1$ would leave similar imprints on the expansion rate of the Universe and clustering of matter. We show how future CMB measurements can be combined with late-time measurements of galaxy clustering and cosmic shear from the Large Synoptic Survey Telescope to alleviate this degeneracy. Together, they are projected to reduce the uncertainty on the neutrino mass sum to 30 meV within this more general cosmological model. Achieving a 3$\sigma$ measurement of the minimal 60 meV mass (or 4$\sigma$ assuming $w=-1$) will require a five-fold improved measurement of the optical depth to reionization, obtainable through a large-scale CMB polarization measurement.

    ↳ astro-ph.COhep-phPRD(2018)·76 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.