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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 307 records · Page 17

India-based neutrino observatory (INO): Physics reach and status report

We present a review of the physics reach and current status of the proposed India-based Neutrino Observatory (INO). We briefly outline details of the INO location and the present status of detector development. We then present the physics goals and simulation studies of the main detector, the magnetised Iron Calorimeter (ICAL) detector, to be housed in INO. The ICAL detector would make precision measurements of neutrino oscillation parameters with atmospheric neutrinos including a measurement of the neutrino mass hierarchy. Additional synergies with other experiments due to the complete insensitivity of ICAL to the CP phase are also discussed.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Heavy gravitino in hybrid inflation

It is known that supersymmetric hybrid inflation model may require severe tunings on the initial condition for large gravitino mass of order 100 - 1000 TeV due to the constant term in the superpotential. We propose a modified hybrid inflation model, where the constant term is suppressed during inflation and generated after inflation by replacing a constant term with dynamical field. In this modified model, successful inflation consistent with large gravitino mass takes place without severe tunings on the initial condition. Constraint from cosmic strings is also relaxed.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Recent results from atmospheric neutrino analysis at Super-Kamiokande

The atmospheric-neutrino sample at Super-Kamiokande is sensitive to all neutrino oscillation parameters. Our recent analyses focus on the sub-dominant effects which includes unknown parameters. The upper limit to {theta}{sub 13} is set to be sin{sup 2}{theta}{sub 13}<0.066 (< 0.122) at 90% confidence level in case of the normal (inverted) mass hierarchy. We confirm our sample has the sensitivity to the CP phase, {delta}{sub CP}. The mass hierarchy test also is performed. CPT violation in the neutrino oscillation is tested with the atmospheric-neutrino sample. However, our result suggests the CPT conservation.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Heating up the Galaxy with hidden photons

We elaborate on the dynamics of ionized interstellar medium in the presence of hidden photon dark matter. Our main focus is the ultra-light regime, where the hidden photon mass is smaller than the plasma frequency in the Milky Way. We point out that as a result of the Galactic plasma shielding direct detection of ultra-light photons in this mass range is especially challenging. However, we demonstrate that ultra-light hidden photon dark matter provides a powerful heating source for the ionized interstellar medium. This results in a strong bound on the kinetic mixing between hidden and regular photons all the way down to the hidden photon masses of order 10{sup −20} eV.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Constraints on massive neutrinos from the CFHTLS angular power spectrum

We use the galaxy angular power spectrum at z ∼ 0.5–1.2 from the Canada-France-Hawaii-Telescope Legacy Survey Wide fields (CFHTLS-Wide) to constrain separately the total neutrino mass Σm{sub ν} and the effective number of neutrino species N{sub eff}. This survey has recently benefited from an accurate calibration of the redshift distribution, allowing new measurements of the (non-linear) matter power spectrum in a unique range of scales and redshifts sensitive to neutrino free streaming. Our analysis makes use of a recent model for the effect of neutrinos on the weakly non-linear matter power spectrum derived from accurate N-body simulations. We show that CFHTLS, combined with WMAP7 and a prior on the Hubble constant provides an upper limit of Σm{sub ν} < 0.29 eV and N{sub eff} = 4.17{sup +1.62}{sub −1.26} (2 σ confidence levels). If we omit smaller scales which may be affected by non-linearities, these constraints become Σm{sub ν} < 0.41 eV and N{sub eff} = 3.98{sup +2.02}{sub −1.20} (2 σ confidence levels). Finally we show that the addition of other large scale structures probes can further improve these constraints, demonstrating that high redshift large volumes surveys such as CFHTLS are complementary to other cosmological probes of the neutrino mass.

79 ASTRONOMY AND ASTROPHYSICS↗

Confronting recent results from selected direct and indirect dark matter searches and the Higgs boson with supersymmetric models with non-universal gaugino masses

In this paper we study a class of supersymmetric models with non-universal gaugino masses that arise from a mixture of SU(5) singlet and non-singlet representations, i.e. a combination of 1, 24, 75 and 200. Based on these models we calculate the expected dark matter signatures within the linear combination 1 ⊕ 24 ⊕ 75 ⊕ 200. We confront the model predictions with the detected boson as well as current experimental limits from selected indirect and direct dark matter search experiments ANTARES respective IceCube and XENON. We comment on the detection/exclusion capability of the future XENON 1t project. For the investigated parameter span we could not find a SU(5) singlet model that fulfils the Higgs mass and the relic density constraint. In contrary, allowing a mixture of 1 ⊕ 24 ⊕ 75 ⊕ 200 enables a number of models fulfilling these constraints.

79 ASTRONOMY AND ASTROPHYSICS↗

Search for resonant absorption of solar axions emitted in M1-transitions in {sup 83}Kr nuclei: Second stage of the experiment

Axions with energies of 9.4 keV putatively produced in the Sun via an M1-transition in the {sup 83}Kr nucleus are searched for using the reaction of resonant absorption: A +{sup 83}Kr →{sup 83}Kr* →{sup 83}Kr + γ, e (9.4 keV). The γ-quanta and electrons are detected with a proportional counter filled with krypton and placed in a low-background setup. A new upper limit on the axion–nucleon coupling constant is imposed: |g{sup 3}{sub AN} g{sup 0}{sub AN}|≤1.02 10{sup 6}. For the hadronic axion, this implies a new upper limit on the axion mass: m{sub A }≤ 79eV at the 95% confidence level.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

New observations in the MiniBooNE experiment

The MiniBooNE neutrino oscillation search experiment at Fermilab has recently reported results from a search for microe oscillations, using a data sample corresponding to 5.66 x 1020 protons on target in anti-neutrino mode. The experiment is now se nsitive to the excess of microe events observed by Los Alamos Liquid Scintillator Neutrino Detector (LSND). MiniBooNE data are consistent with microe oscillations in the m2 range of 0.1 to 1.0 eV2 and with the evidence for antineutrino oscillations from L SND.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

D-brane SM-like and scalar dark matter in type IIA superstring theory

In light of the present LHC Run II at √s = 13 TeV, a SM-like string model is studied. Specifically, a singlet S scalar-extended SM given in terms of four stacks of intersecting D6-branes in a type IIA superstring compactification producing a large gauge symmetry is examined. The scales involved are dealt with. According to the dark matter relic density, the mass of the scalar dark matter beyond the SM m{sub S} ≲ 10{sup 3} GeV and the corresponding Higgs portal couplings λ{sub SH} ≲ 10{sup –8} have been obtained.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

First result of the experimental search for the 9.4 keV solar axion reactions with {sup 83}Kr in the copper proportional counter

The experimental search for solar hadronic axions is started at the Baksan Neutrino Observatory of the Institute for Nuclear Researches of Russian Academy of Science (BNO INR RAS). It is assumed that axions are created in the Sun during M1 transition between the first thermally excited level at 9.4 keV and the ground state in {sup 83}Kr. The experiment is based on axion detection via resonant absorption process by the same nucleus in the detector. The big copper proportional counter filled with krypton is used to detect signals from axions. The experimental setup is situated in the deep underground low background laboratory. No evidence of axion detection were found after the 26.5 days data collection. Resulting new upper limit on axion mass is m{sub A} ≤ 130 eV at 95% C.L.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Nucleon QCD sum rules in the instanton medium

We try to find grounds for the standard nucleon QCD sum rules, based on a more detailed description of the QCD vacuum. We calculate the polarization operator of the nucleon current in the instanton medium. The medium (QCD vacuum) is assumed to be a composition of the small-size instantons and some long-wave gluon fluctuations. We solve the corresponding QCD sum rule equations and demonstrate that there is a solution with the value of the nucleon mass close to the physical one if the fraction of the small-size instantons contribution is w{sub s} ≈ 2/3.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Applications of AdS/QCD and Light-Front Holography to Baryon Physics

The correspondence between theories in anti--de Sitter space and field theories in physical space-time leads to an analytic, semiclassical model for strongly-coupled QCD which has scale invariance at short distances and color confinement at large distances. These equations, for both mesons and baryons, give a very good representation of the observed hadronic spectrum, including a zero mass pion. Light-front holography allows hadronic amplitudes in the AdS fifth dimension to be mapped to frame-independent light-front wavefunctions of hadrons in physical space-time, thus providing a relativistic description of hadrons at the amplitude level. The meson and baryon wave-functions derived from light-front holography and AdS/QCD also have remarkable phenomenological features, including predictions for the electromagnetic form factors and decay constants. The approach can be systematically improved using light-front Hamiltonian methods. Some novel features of QCD for baryon physics are also discussed.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Hidden sector dark matters and elusive Higgs boson(s) at the LHC

We consider two types of hidden sector dark matters (DM's), with and without QCD-like new strong interaction with confinement properties, and their interplays with the Standard Model (SM) Higgs boson. Assuming the hidden sector has only fermions (and gauge bosons in case of strongly interacting hidden sector), we have to introduce a real singlet scalar boson S as a messenger between the SM and the hidden sector dark matters. This singlet scalar will mix with the SM Higgs boson h, and we expect there are two Higgs-like scalar bosons H{sub 1} and H{sub 2}. Imposing all the relevant constraints from collider search bounds on Higgs boson, DM scattering cross section on proton and thermal relic density, we find that one of the two Higgs-like scalar bosons can easily escape the detections at the LHC. Recent results on the Higgs-like new boson with mass around with 125 GeV from the LHC will constrain this class of models, which is left for future study.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Bound states in a strong magnetic field

We expect a strong magnetic field to be produced in the perpendicular direction to the reaction plane, in a noncentral heavy-ion collision . The strength of the magnetic field is estimated to be eB{approx}m{sup 2}{sub {pi}}{approx} 0.02 GeV{sup 2} at the RHIC and eB{approx} 15m{sup 2}{sub {pi}}{approx} 0.3 GeV{sup 2} at the LHC. We investigate the effects of the magnetic field on B{sup 0} and D{sup 0} mesons, focusing on the changes of the energy levels and of the mass of the bound states.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Study of the D*ρ system using QCD sum rules

In this proceeding we present a study of the D*ρ system made by using the method of QCD sum rules. Considering isospin and spin projectors, we investigate the different configurations and obtain three D* mesons with isospin I = 1/2, spin S = 0, 1, 2 and with masses 2500±67 MeV, 2523±60 MeV, and 2439±119 MeV, respectively. The last state can be related to D{sub 2}{sup *} (2460) (spin 2) listed by the Particle Data Group, while one of the first two might be associated with D*(2640), whose spin-parity is unknown. In the case of I = 3/2 we also find evidences of three states with spin 0, 1 and 2, respectively, with masses 2467±82 MeV, 2420±128 MeV, and 2550±56 MeV.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Discovery potential of xenon-based neutrinoless double beta decay experiments in light of small angular scale CMB observations

The South Pole Telescope (SPT) has probed an expanded angular range of the CMB temperature power spectrum. Their recent analysis of the latest cosmological data prefers nonzero neutrino masses, with Σm{sub ν} = (0.32±0.11) eV. This result, if confirmed by the upcoming Planck data, has deep implications on the discovery of the nature of neutrinos. In particular, the values of the effective neutrino mass m{sub ββ} involved in neutrinoless double beta decay (ββ0ν) are severely constrained for both the direct and inverse hierarchy, making a discovery much more likely. In this paper, we focus in xenon-based ββ0ν experiments, on the double grounds of their good performance and the suitability of the technology to large-mass scaling. We show that the current generation, with effective masses in the range of 100 kg and conceivable exposures in the range of 500 kg·year, could already have a sizeable opportunity to observe ββ0ν events, and their combined discovery potential is quite large. The next generation, with an exposure in the range of 10 ton·year, would have a much more enhanced sensitivity, in particular due to the very low specific background that all the xenon technologies (liquid xenon, high-pressure xenon and xenon dissolved in liquid scintillator) can achieve. In addition, a high-pressure xenon gas TPC also features superb energy resolution. We show that such detector can fully explore the range of allowed effective Majorana masses, thus making a discovery very likely.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Measurement of the top quark mass in dileptonic top quark pair decays with √s = 7 TeV ATLAS data

The top quark mass in dileptonic top quark pair decays was measured using 4.7 fb{sup –1} of √s = 7 TeV proton-proton (pp) collision data recorded by the ATLAS experiment at the LHC in 2011. The event topology is characterized by the presence of two charged leptons, at least two neutrinos and several jets, two of which originate from bottom quarks. Using the template method and the m{sub ℓb} observable, defined as the average invariant mass of the two charged lepton plus b-jet pairs in each event, the top quark mass is measured to be 173.09 ± 0.64(stat) ± 1.50(syst) GeV. This proceeding is based on a preliminary result, which has been superseded meanwhile.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

A DESCRIPTION OF QUASAR VARIABILITY MEASURED USING REPEATED SDSS AND POSS IMAGING

We provide a quantitative description and statistical interpretation of the optical continuum variability of quasars. The Sloan Digital Sky Survey (SDSS) has obtained repeated imaging in five UV-to-IR photometric bands for 33,881 spectroscopically confirmed quasars. About 10,000 quasars have an average of 60 observations in each band obtained over a decade along Stripe 82 (S82), whereas the remaining {approx}25,000 have 2-3 observations due to scan overlaps. The observed time lags span the range from a day to almost 10 years, and constrain quasar variability at rest-frame time lags of up to 4 years, and at rest-frame wavelengths from 1000 A to 6000 A. We publicly release a user-friendly catalog of quasars from the SDSS Data Release 7 that have been observed at least twice in SDSS or once in both SDSS and the Palomar Observatory Sky Survey, and we use it to analyze the ensemble properties of quasar variability. Based on a damped random walk (DRW) model defined by a characteristic timescale and an asymptotic variability amplitude that scale with the luminosity, black hole mass, and rest wavelength for individual quasars calibrated in S82, we can fully explain the ensemble variability statistics of the non-S82 quasars such as the exponential distribution of large magnitude changes. All available data are consistent with the DRW model as a viable description of the optical continuum variability of quasars on timescales of {approx}5-2000 days in the rest frame. We use these models to predict the incidence of quasar contamination in transient surveys such as those from the Palomar Transient Factory and Large Synoptic Survey Telescope.

79 ASTRONOMY AND ASTROPHYSICS↗