Search

We have imaged the bipolar planetary nebula M2-9 using SOFIA's FORCAST instrument in six wavelength bands between 6.6 and 37.1 $\mu m$. A bright central point source, unresolved with SOFIA's $\sim$ 4${''}$-to-5${''}$ beam, is seen at each wavelength, and the extended bipolar lobes are clearly seen at 19.7 $\mu m$ and beyond. The photometry between 10 and 25 $\mu m$ is well fit by the emission predicted from a stratified disk seen at large inclination, as has been proposed for this source by Lykou et al and by Smith and Gehrz. The principal new results in this paper relate to the distribution and properties of the dust that emits the infrared radiation. In particular, a considerable fraction of this material is spread uniformly through the lobes, although the dust density does increase at the sharp outer edge seen in higher resolution optical images of M2-9. The dust grain population in the lobes shows that small ($$ 1 $\mu m$) particles appear to be present in roughly equal amounts by mass. We suggest that collisional processing within the bipolar outflow plays an important role in establishing the particle size distribution., Comment: 40 pages, 9 figures, 2 tables

In this paper we introduce a simple renormalizable model of an extended color gauge sector in which the third-generation quarks couple differently than the lighter quarks. In addition to a set of heavy color-octet vector bosons (colorons), the model also contains a set of heavy weak vector quarks. Mixing between the third-generation of quarks and the first two is naturally small, and occurs only through the (suppressed) mixing of all three generations with the heavy vector quarks. We discuss the constraints on this model arising from limits on flavor-changing neutral currents and from collider searches for the colorons and vector quarks, and discuss the prospects for discovery at the LHC., 18 pages, 13 pdf included figures. Typos fixed, corresponds to published version

A brief remark is made about Hutchinson´s paper et al (2012 E.J.P) about the ground configuration of the Helium atom and the importance of continuum states. The purpose of our comment is twofold: first, to indicate that even using good basis set, obtained by the Self-Consistent Hartree-Fock method, the contribution of other bound states and continuum ones is of some importance to calculate energy levels; on the other hand, to emphasize that continuum states can be of great importance to satisfy several rigurous sum rules. Fil: Di Rocco, Hector Omar. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Instituto de Fisica Arroyo Seco; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tandil; Argentina

Nuclear instruments & methods in physics research / A 729, 153 - 181 (2013). doi:10.1016/j.nima.2013.07.015, The Collider Detector at Fermilab (CDF) pursues a broad physics program at Fermilab's Tevatron collider. Between Run II commissioning in early 2001 and the end of operations in September 2011, the Tevatron delivered 12 fb-1 of integrated luminosity of p-pbar collisions at sqrt(s)=1.96 TeV. Many physics analyses undertaken by CDF require heavy flavor tagging with large charged particle tracking acceptance. To realize these goals, in 2001 CDF installed eight layers of silicon microstrip detectors around its interaction region. These detectors were designed for 2--5 years of operation, radiation doses up to 2 Mrad (0.02 Gy), and were expected to be replaced in 2004. The sensors were not replaced, and the Tevatron run was extended for several years beyond its design, exposing the sensors and electronics to much higher radiation doses than anticipated. In this paper we describe the operational challenges encountered over the past 10 years of running the CDF silicon detectors, the preventive measures undertaken, and the improvements made along the way to ensure their optimal performance for collecting high quality physics data. In addition, we describe the quantities and methods used to monitor radiation damage in the sensors for optimal performance and summarize the detector performance quantities important to CDF's physics program, including vertex resolution, heavy flavor tagging, and silicon vertex trigger performance., Published by North-Holland Publ. Co., Amsterdam

LUX is a two-phase (liquid/gas) xenon time projection chamber designed to detect nuclear recoils from interactions with dark matter particles. Signals from the LUX detector are processed by custom-built analog electronics which provide properly shaped signals for the trigger and data acquisition (DAQ) systems. The DAQ is composed of commercial digitizers with firmware customized for the LUX experiment. Data acquisition systems in rare-event searches must accommodate high rate and large dynamic range during precision calibrations involving radioactive sources, while also delivering low threshold for maximum sensitivity. The LUX DAQ meets these challenges using real-time baseline suppression that allows for a maximum event acquisition rate in excess of 1.5 kHz with virtually no deadtime. This paper describes the LUX DAQ and the novel acquisition techniques employed in the LUX experiment. © 2011 Elsevier B.V. All rights reserved.

This paper surveys the basic ideas and results on fundamental models of drift wave turbulence, the formation of zonal flows, shear suppression of turbulence and transport, coupled drift wave and zonal flow dynamics and application to transport bifurcations and transitions. Application to vortex dynamics and zonal flow phenomena in EMHD systems are discussed, as well. These are relevant to aspects of ICF and laser plasma physics. Throughout, an effort is made to focus on fundamental physics ideas.

Strong astrophysical shocks, diffusively accelerating cosmic rays (CR) ought to develop CR precursors. The length of such precursor $L_{p}$ is believed to be set by the ratio of the CR mean free path $\lambda$ to the shock speed, i.e., $L_{p}\sim c\lambda/V_{sh}\sim cr_{g}/V_{sh}$, which is formally independent of the CR pressure $P_{c}$. However, the X-ray observations of supernova remnant shocks suggest that the precursor scale may be significantly shorter than $L_{p}$ which would question the above estimate unless the magnetic field is strongly amplified and the gyroradius $r_{g}$ is strongly reduced over a short (unresolved) spatial scale. We argue that while the CR pressure builds up ahead of the shock, the acceleration enters into a strongly nonlinear phase in which an acoustic instability, driven by the CR pressure gradient, dominates other instabilities (at least in the case of low $\beta$ plasma). In this regime the precursor steepens into a strongly nonlinear front whose size scales with \emph{the CR pressure}as $L_{f}\sim L_{p}\cdot(L_{s}/L_{p})^{2}(P_{c}/P_{g})^{2}$, where $L_{s}$ is the scale of the developed acoustic turbulence, and $P_{c}/P_{g}$ is the ratio of CR to gas pressure. Since $L_{s}\ll L_{p}$, the precursor scale reduction may be strong in the case of even a moderate gas heating by the CRs through the acoustic and (possibly also) the other instabilities driven by the CRs., Comment: EPS 2010 paper, to appear in PPCF

In this paper we discuss the global symmetries and the renormalizibility of Lee-Wick scalar QED. In particular, in the "auxiliary-field" formalism we identify softly broken SO(1,1) global symmetries of the theory. We introduce SO(1,1) invariant gauge-fixing conditions that allow us to show in the two-field formalism directly that the number of superficially divergent amplitudes in a LW Abelian gauge theory is finite. To illustrate the renormalizability of the theory, we explicitly carry out the one-loop renormalization program in LW scalar QED and demonstrate how the counterterms required are constrained by the joint conditions of gauge- and SO(1,1)-invariance. We also compute the one-loop beta-functions in LW scalar QED and contrast them with those of ordinary scalar QED., 17 pages, 3 eps figures included. Incorporates suggestions by referee; title changed

The Lick AGN Monitoring Project targeted 13 nearby Seyfert 1 galaxies with the intent of measuring the masses of their central black holes using reverberation mapping. The sample includes 12 galaxies selected to have black holes with masses roughly in the range 10^6-10^7 solar masses, as well as the well-studied AGN NGC 5548. In conjunction with a spectroscopic monitoring campaign, we obtained broad-band B and V images on most nights from 2008 February through 2008 May. The imaging observations were carried out by four telescopes: the 0.76-m Katzman Automatic Imaging Telescope (KAIT), the 2-m Multicolor Active Galactic Nuclei Monitoring (MAGNUM) telescope, the Palomar 60-in (1.5-m) telescope, and the 0.80-m Tenagra II telescope. Having well-sampled light curves over the course of a few months is useful for obtaining the broad-line reverberation lag and black hole mass, and also allows us to examine the characteristics of the continuum variability. In this paper, we discuss the observational methods and the photometric measurements, and present the AGN continuum light curves. We measure various variability characteristics of each of the light curves. We do not detect any evidence for a time lag between the B- and V-band variations, and we do not find significant color variations for the AGNs in our sample., Comment: 16 pages, 20 figures, 8 tables, accepted for publication in ApJS

We analyze atomic photoelectron momentum distributions induced by bichromatic and monochromatic laser fields within the strong field approximation (SFA), separable Coulomb-Volkov approximation (SCVA), and ab initio treatment. We focus on the high frequency regime -- the smallest frequency used is larger than the ionization potential of the atom. We observe a remarkable agreement between the ab initio and velocity gauge SFA results while the velocity gauge SCVA fails to agree. Reasons of such a failure are discussed., Comment: Completely rewritten paper. Ionization by a two-color field is added

Abridged: Subaru Deep Field line-emitting galaxies in four narrow-band filters at low and intermediate redshifts are presented. Broad-band colors, follow-up optical spectroscopy, and multiple NB filters are used to distinguish Ha, [O II], and [O III] emitters between redshifts of 0.07 and 1.47 to construct their luminosity functions (LFs). These LFs are derived down to faint magnitudes, which allows for a more accurate determination of the faint end slope. With a large (N~200-900) sample for each redshift interval, a Schechter profile is fitted to each LF. Prior to dust extinction corrections, the [O III] and [O II] LFs reported in this paper agree reasonably well with those of Hippelein et al. The z=0.08 Ha LF, which reaches two orders of magnitude fainter than Gallego et al., is steeper by 25%. This indicates that there are more low luminosity star-forming galaxies for z1, the star-formation rate densities are more or less constant. The latter is consistent with previous UV and [O II] measurements. Below z, Comment: 26 pages, 15 figures, 36 figure files (25 color; 11 B/W), emulateapj, accepted for publication in ApJ

Complex periodic and aperiodic behaviors are reported in an unstirred Belousov–Zhabotinsky reaction at different concentrations of added electrolytes. A route to chaos following a Ruelle–Takens–Newhouse (RTN) scenario is identified. A 3-fold torus was also found in phase space. In this paper, we prove that the concentration of inert added electrolytes is a bifurcation parameter for the sequence period-1 → period-2 → period-3 → chaos.

We present improved black hole masses for 35 active galactic nuclei (AGNs) based on a complete and consistent reanalysis of broad emission-line reverberation-mapping data. From objects with multiple line measurements, we find that the highest precision measure of the virial product is obtained by using the cross-correlation function centroid (as opposed to the cross-correlation function peak) for the time delay and the line dispersion (as opposed to full width half maximum) for the line width and by measuring the line width in the variable part of the spectrum. Accurate line-width measurement depends critically on avoiding contaminating features, in particular the narrow components of the emission lines. We find that the precision (or random component of the error) of reverberation-based black hole mass measurements is typically around 30%, comparable to the precision attained in measurement of black hole masses in quiescent galaxies by gas or stellar dynamical methods. Based on results presented in a companion paper by Onken et al., we provide a zero-point calibration for the reverberation-based black hole mass scale by using the relationship between black hole mass and host-galaxy bulge velocity dispersion. The scatter around this relationship implies that the typical systematic uncertainties in reverberation-based black hole masses are smaller than a factor of three. We present a preliminary version of a mass-luminosity relationship that is much better defined than any previous attempt. Scatter about the mass-luminosity relationship for these AGNs appears to be real and could be correlated with either Eddington ratio or object inclination., 61 pages, including 8 Tables and 16 Figures. Accepted for publication in The Astrophysical Journal

The search for neutrinoless double beta decay (DBD-0ν) is a powerful tool to establish the correct neutrino mass hierarchy and whether the neutrino is a Majorana or Dirac particle. The Milano group has run several experiments using thermal detectors to search for the 130Te DBD-0ν. The Cuoricino experiment consists of an array of 62 TeO2 thermal detectors for a total mass of about 40 kg, by far the largest cryogenic experiment in the world. The detector installation in the Gran Sasso Underground Laboratory has been recently completed. After a test phase the experiment is now taking data and we report here the preliminary results. Cuoricino is the first step toward the CUORE experiment, which will consists of 1000 TeO2 thermal detectors for a total mass of about 760 kg: in this paper we discuss also the physics potential of both stages for what concerns the DBD-0ν search. PACS: 11.30.Fs Lepton number – 14.60.Pq Neutrino mass and mixing – 23.40.Bw Weak interactions in beta decay

Matter-enhanced antineutrino flavor transformation between $\bar\nu_e$ and $\bar\nu_{\mu(\tau)}$ can occur in supernovae if the vacuum masses for these species satisfy $m_{\bar\nu_e}>m_{\bar\nu_{\mu(\tau)}}$. For $\delta m^2> 1$ eV$^2$, such flavor transformation can affect the electron fraction $Y_e$ in the neutrino-heated supernova ejecta. We point out that such flavor transformation will not drive $Y_e>0.5$ at the $r$-process nucleosynthesis epoch in the best available supernova model for such nucleosynthesis. Consequently, there is no obvious conflict between matter-enhanced antineutrino flavor transformation $\bar\nu_e\rightleftharpoons\bar\nu_{\mu(\tau)}$ and $r$-process nucleosynthesis in the neutrino-heated supernova ejecta., Comment: replace previous corrupted files with uuencoded file for the complete paper

The anomalous dimensions of dimension-six operators in the Standard Model Effective Field Theory (SMEFT) respect holomorphy to a large extent. The holomorphy conditions are reminiscent of supersymmetry, even though the SMEFT is not a supersymmetric theory., Comment: Minor corrections in Table I, see note added at end of paper. The complete SMEFT RGE will be maintained at http://einstein.ucsd.edu/smeft

Astrophysical electron and positron emission, continuum electron and positron capture rates, as well as the associated neutrino energy loss rates are calculated for free nucleons and 226 nuclei with masses between A = 21 and 60. Measured nuclear level information and matrix elements are used where available. Unmeasured matrix elements for allowed transitions are assigned as in Paper I. Simple shell model arguments are used to estimate Gamow-Teller sum rules and collective state resonance excitation energies. The discrete state contribution to the rates, dominated by experimental information and the Fermi transitions, determines the nuclear rates in the regime of temperatures and densities characteristic of the hydrostatic phases of presupernova stellar evolution. At the higher temperatures and densities characteristic of the supernova collapse phase, the nuclear rates are dominated by the Fermi and the Gamow-Teller collective resonance contributions. Also included is the important effect of neutron shell closure blocking of electron capture on neutron-rich nuclei. Uncertainties in the rate calculation are discussed. Reference is made to other treatments of the problem. Results of the calculations on a detailed temperature-density grid are available in computer readable form on magnetic tape upon request to M. J. N.

Stellar electron and positron emission rates and continuum electron and positron capture rates, as well as the associated neutrino energy loss rates, are tabulated for the free nucleons and 226 nuclei with masses between A = 21 and 60. These rates were calculated in accordance with the procedure described in Papers I and II of this series and are presented here in tabular form on an abbreviated temperature and density grid. Results of these calculations on a detailed temperature and density grid are available in computer readable form on magnetic tape upon request to MJN. The stellar weak rate calculation procedure is reviewed, and the results are discussed. Comparison of the stellar weak rates to terrestrial decay rates are made where possible.

The current LHC results make weak scale supersymmetry difficult due to relatively heavy mass of the discovered Higgs boson and the null results of new particle searches. Geometrical supersymmetry breaking from extra dimensions, Scherk-Schwarz mechanism, is possible to accommodate such situations. A concrete example, the Compact Supersymmetry model, has a compressed spectrum ameliorating the LHC bounds and large mixing in the top and scalar top quark sector with $|A_t|\sim 2m_{\tilde{t}}$ which radiatively raises the Higgs mass. While the zero mode contribution of the model has been considered, in this paper we calculate the Kaluza-Klein tower effect to the Higgs mass. Although such contributions are naively expected to be as small as a percent level for 10 TeV Kaluza-Klein modes, we find the effect significantly enhances the radiative correction to the Higgs quartic coupling by from 10 to 50 %. This is mainly because the top quark wave function is pushed out from the brane, which makes the top mass depend on higher powers in the Higgs field. As a result the Higgs mass is enhanced up to 15 GeV from the previous calculation. We also show the whole parameter space is testable at the LHC run II., 30 pages, 8 figures, appendix C added, conclusion unchanged, journal version

International audience; This paper presents a maximum-likelihood algorithm for combining sky maps with disparate sky coverage, angular resolution and spatially varying anisotropic noise into a single map of the sky. We use this to merge hundreds of individual maps covering the 2008–2018 ACT observing seasons, resulting in by far the deepest ACT maps released so far. We also combine the maps with the full Planck maps, resulting in maps that have the best features of both Planck and ACT: Planck's nearly white noise on intermediate and large angular scales and ACT's high-resolution and sensitivity on small angular scales. The maps cover over 18 000 square degrees, nearly half the full sky, at 100, 150 and 220 GHz. They reveal 4 000 optically-confirmed clusters through the Sunyaev Zel'dovich effect (SZ) and 18 500 point source candidates at > 5σ, the largest single collection of SZ clusters and millimeter wave sources to date. The multi-frequency maps provide millimeter images of nearby galaxies and individual Milky Way nebulae, and even clear detections of several nearby stars. Other anticipated uses of these maps include, for example, thermal SZ and kinematic SZ cluster stacking, CMB cluster lensing and galactic dust science. The method itself has negligible bias. However, due to the preliminary nature of some of the component data sets, we caution that these maps should not be used for precision cosmological analysis. The maps are part of ACT DR5, and will be made available on \href{https://lambda.gsfc.nasa.gov/}{LAMBDA} no later than three months after the journal publication of this article, along with an interactive sky atlas.