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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 343 records · Page 19
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DOE OSTI2012

Alchemical inflation: inflaton turns into Higgs

We propose a new inflation model in which a gauge singlet inflaton turns into the Higgs condensate after inflation. The inflationary path is characterized by a moduli space of supersymmetric vacua spanned by the inflaton and Higgs field. The inflation energy scale is related to the soft supersymmetry breaking, and the Hubble parameter during inflation is smaller than the gravitino mass. The initial condition for the successful inflation is naturally realized by the pre-inflation in which the Higgs plays a role of the waterfall field.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2013

Non-Gaussianities from the Standard Model Higgs

We have recently proposed that the Standard Model Higgs might be responsible for generating the cosmological perturbations of the universe by acting as an isocurvature mode during a de Sitter inflationary stage. In this paper we study the level of non-Gaussianity in the cosmological perturbations which are inevitably generated due to the non-linearities of the Standard Model Higgs potential. In particular, for the current central value of the top mass, we find that a future detection of non-Gaussianity would exclude the detection of tensor modes by the PLANCK satellite.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2016

Probing neutrino mass hierarchy by comparing the charged-current and neutral-current interaction rates of supernova neutrinos

The neutrino mass hierarchy is one of the neutrino fundamental properties yet to be determined. We introduce a method to determine neutrino mass hierarchy by comparing the interaction rate of neutral current (NC) interactions, ν(ν-bar)+p→ν(ν-bar)+p, and inverse beta decays (IBD), ν-bar{sub e}+p→n+e{sup +}, of supernova neutrinos in scintillation detectors. Neutrino flavor conversions inside the supernova are sensitive to neutrino mass hierarchy. Due to Mikheyev-Smirnov-Wolfenstein effects, the full swapping of ν-bar{sub e} flux with the ν-bar{sub x} (x=μ, τ) one occurs in the inverted hierarchy, while such a swapping does not occur in the normal hierarchy. As a result, more high energy IBD events occur in the detector for the inverted hierarchy than the high energy IBD events in the normal hierarchy. By comparing IBD interaction rate with the mass hierarchy independent NC interaction rate, one can determine the neutrino mass hierarchy.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2017

Searching for Constraints on Starobinsky’s Model with a Disappearing Cosmological Constant on Galaxy Cluster Scales

Predictions of the f(R)-gravity model with a disappearing cosmological constant (Starobinsky’s model) on scales characteristic of galaxies and their clusters are considered. The absence of a difference in the mass dependence of the turnaround radius between Starobinsky’s model and General Relativity accessible to observation at the current accuracy of measurements has been established. This is true both for small masses (from 10{sup 9}M{sub Sun}) corresponding to an individual galaxy and for masses corresponding to large galaxy clusters (up to 10{sup 15}M{sub Sun}). The turnaround radius increases with parameter n for all masses. Despite the fact that some models give a considerably smaller turnaround radius than does General Relativity, none of the models goes beyond the bounds specified by the observational data.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2011

Disentangling the various Mechanisms of neutrinoless double beta decay to extract the neutrino mass

It is well known that there exist many mechanisms that may contribute to neutrinoless double beta decay. By exploiting the fact that the associated nuclear matrix elements are target dependent we show that, given definite experimental results on a sufficient number of targets, one can determine or sufficiently constrain all lepton violating parameters including the mass term. As a specific example we show that, given the observation of the 0{nu}{beta}{beta}-decay in three different nuclei, e.g. {sup 76}Ge, {sup 100}Mo and {sup 130}Te, and assuming just three active lepton number violating parameters, e.g. light and heavy neutrino mass mechanisms in left handed currents as well as R-parity breaking SUSY mechanism, one may determine all lepton violating parameters, provided that they are relatively real.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2012

Spontaneous parity violation and SUSY strong gauge theory

We suggest simple models of spontaneous parity violation in supersymmetric strong gauge theory. We focus on left-right symmetric model and investigate vacuum with spontaneous parity violation. Non-perturbative effects are calculable in supersymmetric gauge theory, and we suggest new models. Our models show confinement, so that we try to understand them by using a dual description of the theory. The left-right symmetry breaking and electroweak symmetry breaking are simultaneously occurred with the suitable energy scale hierarchy. This structure has several advantages compared to the MSSM. The scale of the Higgs mass (left-right breaking scale) and that of VEVs are different, so the SUSY little hierarchy problems are absent. The second model also induces spontaneous supersymmetry breaking.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2013

Taming Landau singularities in QCD perturbation theory: The analytic approach 2.0

The aim of this topical article is to outline the fundamental ideas underlying the recently developed Fractional Analytic Perturbation Theory (FAPT) of QCD and present its main calculational tools together with key applications. For this, it is first necessary to review previous methods to apply QCD perturbation theory at low spacelike momentum scales, where the influence of the Landau singularities becomes inevitable. Several concepts are considered and their limitations are pointed out. The usefulness of FAPT is discussed in terms of two characteristic hadronic quantities: the perturbatively calculable part of the pion’s electromagnetic form factor in the spacelike region and the Higgs-boson decay into a b b-bar pair in the timelike region. In the first case, the focus is on the optimization of the prediction with respect to the choice of the renormalization scheme and the dependence on the renormalization and the factorization scales. The second case serves to show that the application of FAPT to this reaction reaches already at the four-loop level an accuracy of the order of 1%, avoiding difficulties inherent in the standard perturbative expansion. The obtained results are compared with estimates from fixed-order and contour-improved QCD perturbation theory. Using the brand-new Higgs mass value of about 125 GeV, measured at the Large Hadron Collider (CERN), a prediction for Γ{sub H→b b-bar }= 2.4 ± 0.15 MeV is extracted.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2013

Relation between T{sub cc,bb} and X{sub c,b} from QCD

We use double ratio of QCD (spectral) sum rules, to study the ratio masses of T{sub cc} and X(3872) structures, assuming that they are described respectively by the DD* and D-barD* molecular currents. In this approach and within our approximation, we found that the masses of these two states are almost degenerated. In addition, if the observed Belle resonance X(3872) is a D-barD* molecule, then the DD* molecule should exists with approximately the same mass. We have studied an extension for the case including bottom quark. In this situation, our results indicates the same conclusion.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2013

Chiral symmetry in a hot and dense magnetic medium

We consider the Linear Sigma Model (LSM) in the Mean Field Approximation (MFA) in order to analyze hot and dense two flavor quark matter subject to strong magnetic fields. We pay especial attention to the case of a finite chemical potential, which has not yet been fully explored. Here, we investigate the strength of the chiral transition and the behavior of the sigma meson mass for {mu}= 0 and {mu}{ne} 0 under strong magnetic fields, as well as its effects over the T-{mu} plane.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2013

Susy seesaw inflation and NMSO(10)GUT

We show that Supersymmetric models with Type I seesaw neutrino masses support slow roll inflection point inflation. The inflaton is the D-flat direction labelled by the chiral invariant HLN composed of the Higgs(H), slepton(L) and conjugate sneutrino(N) superfields. The scale of inflation and fine tuning is set by the conjugate neutrino Majorana mass M{sub {nu}{sup c}}{approx} 10{sup 6} - 10{sup 12} GeV. The cubic term in the (quartic) inflaton potential is dominantly from superpotential (not soft Susy breaking) couplings. The tuning conditions are thus insensitive to soft supersymmetry breaking parameters and are generically much less stringent than for previous 'A-term' inflation scenarios controlled by mass scales {approx}TeV. WMAP limits on the ratio of tensor to scalar perturbations limit the scale M controlling inflection point inflation: M < 7.9 Multiplication-Sign 10{sup 13} GeV. 'Instant preheating' is operative and dumps the inflaton energy into MSSM modes giving a high reheat temperature: T{sub rh} Almost-Equal-To M{sub {nu}{sup c(3/4)}}10{sup 6} GeV {approx} 10{sup 11} - 10{sup 15} GeV. A large gravitino mass > 50 TeV is therefore required to avoid over closure by reheat produced gravitinos. 'Instant preheating' and NLH inflaton facilitate production of right handed neutrinos during inflaton decay and thus non-thermal leptogenesis in addition to thermal leptogenesis. We show that the embedding in the fully realistic New Minimal Supersymmetric SO(10) GUT requires use of the heaviest righthanded neutrino mass as the controlling scale but the possibility of a measurable tensor scalar perturbation ratio seems marginal. We examine the parametric difficulties remaining.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2013

Study of quantum spin correlations of relativistic electron pairs - Testing nonlocality of relativistic quantum mechanics

The Polish-German project QUEST aims at studying relativistic quantum spin correlations of the Einstein-Rosen-Podolsky-Bohm type, through measurement of the correlation function and the corresponding probabilities for relativistic electron pairs. The results will be compared to theoretical predictions obtained by us within the framework of relativistic quantum mechanics, based on assumptions regarding the form of the relativistic spin operator. Agreement or divergence will be interpreted in the context of non-uniqueness of the relativistic spin operator in quantum mechanics as well as dependence of the correlation function on the choice of observables representing the spin. Pairs of correlated electrons will originate from the Mo/ller scattering of polarized 15 MeV electrons provided by the superconducting Darmstadt electron linear accelerator S-DALINAC, TU Darmstadt, incident on a Be target. Spin projections will be determined using the Mott polarimetry technique. Measurements (starting 2013) are planned for longitudinal and transverse beam polarizations and different orientations of the beam polarization vector w.r.t. the Mo/ller scattering plane. This is the first project to study relativistic spin correlations for particles with mass.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2012

Lateral distribution of radio emission and its dependence on air shower longitudinal development

The lateral distribution function (LDF) of radio emission from an extensive air shower is considered as the basic signature sensitive to the shower longitudinal development and, as a consequence, to the mass of a primary cosmic ray's particle that initiated a given shower. The peculiarities in the LDF's structure as well as their sensitivity to the height of shower maximum are investigated and explained.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2015

Exploring variations in the gauge sector of a six-dimensional flavour model

In the context of extra-dimensional models that describe three families of fermions (including their masses and mixing in terms of a single 6-dimensional family), we explore possible variations (including of the extra dimensions) and argue that the apparent plethora of variants does not lead to drastic changes in the expected phenomenology.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2011

Photoproduction of K{Sigma}(1385) from the nucleon

The reactions of K{Sigma}(1385) photoproduction, i.e., {gamma}p {yields} K{sup +}{Sigma}{sup 0}(1385) and {gamma} {yields} K{sup +}{Sigma}{sup -}(1385), are investigated in the resonance energy region for studying the role of the nucleon and {Delta} resonances of masses around 2 GeV. The Lagrangians for describing the decays of these resonances into the K{Sigma}(1385) channel are constructed and the decay amplitudes are obtained, which allows us to determine the coupling constants using the predictions of quark models or the data listed by the Particle Data Group. The resulting cross sections are compared to the data from the Thomas Jefferson National Accelerator Facility and the SPring-8, which indicates nontrivial contributions from the two-star-rated resonances in the Particle Data Group as well as from some missing resonances predicted by a quark model.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2013

Diffractive production of charm quark/antiquark pairs at RHIC and LHC

We have discussed single and central diffractive production of c(bar sign)c pairs in the Ingelman-Schlein model. In these calculations we have included diffractive parton distributions obtained by the H1 collaboration at HERA and absorption effects neglected in some early calculations in the literature. The absorption effects which are responsible for the naive Regge factorization breaking cause that the cross section for diffractive processes is much smaller than that for the fully inclusive case, but could be measured at RHIC and LHC by imposing special condition on rapidity gaps. We discuss also different approaches to diffractive production of heavy quark/antiquark [1, 2, 3]. The particular mechanism is similar to the diffractive dissociation of virtual photons into quarks, which drives diffractive deep inelastic production of charm in the low-mass diffraction, or large {beta}-region.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2013

Complementarity of dark matter direct detection: the role of bolometric targets

We study how the combined observation of dark matter in various direct detection experiments can be used to determine the phenomenological properties of WIMP dark matter: mass, spin-dependent (SD) and spin-independent (SI) scattering cross section off nucleons. A convenient choice of target materials, including nuclei that couple to dark matter particles through a significantly different ratio of SD vs SI interactions, could break the degeneracies in the determination of those parameters that a single experiment cannot discriminate. In this work we investigate different targets that can be used as scintillating bolometers and could provide complementary information to germanium and xenon detectors. We observe that Al{sub 2}O{sub 3} and LiF bolometers could allow a good reconstruction of the DM properties over regions of the parameter space with a SD scattering cross section as small as 10{sup −5} pb and a SI cross section as small as 5 × 10{sup −10} pb for a 50 GeV WIMP. In the case of a CaWO{sub 4} bolometer the area in which full complementarity is obtained is smaller but we show that it can be used to determine the WIMP mass and its SI cross section. For each target we study the required exposure and background.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2017

QCD development in the early universe

The high-energy limit of Quantum Chromodynamics is generated by the contraction of its gauge groups. Contraction parameters are taken identical with those of the Electroweak Model and tend to zero when energy increases. At the infinite energy limit all quarks lose masses and have only one color degree of freedom. The limit model represents the development of Quantum Chromodynamics in the early Universe from the Big Bang up to the end of several milliseconds.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2011

Valence quark contributions for the {gamma}N{yields}P{sub 11}(1440) transition

A covariant spectator quark model is applied to estimate the valence quark contributions to the F{sub 1}{sup *}(Q{sup 2}) and F{sub 2}{sup *}(Q{sup 2}) transition form factors for the {gamma}N{yields}P{sub 11}(1440) reaction. The Roper resonance, P{sub 11}(1440), is assumed to be the first radial excitation of the nucleon. The model requires no extra parameters except for those already fixed by the previous studies for the nucleon. The results are consistent with the experimental data in the high Q{sup 2} region, and those from the lattice QCD. Finally the model is also applied to estimate the meson cloud contributions from the CLAS and MAID analysis.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗