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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 91 records · Page 5
All sourcesNASA NTRSDOE OSTI
DOE OSTI2011

Hadron Physics at FAIR

The new FAIR facility in Darmstadt has a broad program in the field of hadron and nuclear physics utilizing ion beams with unprecedented intensity and accuracy. The hadron physics program centers around the the high-energy storage ring HESR for antiprotons and the PANDA experiment that is integrated in it. The physics program includes among others topics like hadron spectroscopy in the charmonium mass region and below, hyperon physics, electromagnetic processes and charm in nuclei.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2011

Physics Prospects with GlueX

The new experiment GlueX is currently being constructed at Jefferson Lab. The experiment was designed to search for hybrid mesons with exotic-quantum-numbers using a beam of linearly polarized photons incident on a liquid hydrogen target. We will discuss the discovery potential of the GlueX experiment and briefly overview its physics program.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2011

Measurement of the transition form factor of {eta} meson with WASA-at-COSY

Reaction {eta}{yields}e{sup +}e{sup -}{gamma} is used to investigate the transition form factor of {eta} meson with WASA detector at COSY. Where the {eta} meson is produced in pp collision at 1.4 GeV. We present the analysis techniques and preliminary results of {eta} Dalitz decays.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2011

Light and heavy at the end of the funnel

We show that, by taking a bare mass spectrum with constant spacings for the quark-antiquark propagators, which is subject to considerable mass shifts from meson loops, one adequately describes a large variety of mesonic resonances, from the light scalars to the bb-bar states. All our results indicate that a harmonic-oscilator spectrum with universal frequency, in combination with coupled-channel effects, does a much better job than the qq-bar spectrum of the funnel potential.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2011

Incoherent {phi} photo-production from deuteron in SPring-8/LEPS

We present measurements of differential cross sections and decay asymmetries of incoherent {phi}-meson photo-production from the deuteron at forward angles using linearly polarized photons beam in energy range from the production threshold to E = 2.4 GeV. The experiment was performed at the SPring-8/LEPS facility. The differential cross section of incoherent production shows a large suppression compared with the free proton case. The reduction for the deuteron cannot be clearly explained in terms of simple isospin asymmetry. The decay asymmetry of incoherent {phi} photo-production shows that the eta exchange process is small. Since the exclusive K{sup +}K{sup -}p cross section shows the same reduction with incoherent, both the proton and neutron cross section reduce similarly. Consequently, the {pi}-{eta} interference effect is small too. The present results suggest that our understanding of {phi} photo-production within a nucleus should be rearranged.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2012

Hadron physics as Seiberg dual of QCD

We try to identify the light hadron world as the magnetic picture of QCD. We take both phenomenological and theoretical approaches to this hypothesis, and find that the interpretation seems to show interesting consistencies. In particular, one can identify the {rho} and {omega} mesons as the magnetic gauge bosons, and the Higgs mechanism for them provides a dual picture of the color confinement{sup 1}.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2012

Maximum mass of neutron stars with quark matter core

We propose a new strategy to construct the equation of state (EOS) for neutron stars (NSs) with hadron-quark (H-Q) phase transition, by considering three density-regions. We supplement the EOS at H-Q region, very uncertain due to the confinement-deconfinement problems, by sandwitching in between and matching to the relatively 'well known' EOSs, i.e., the EOS at lower densities (H-phase up to several times nuclear density, calculated from a G-matrix approach) and that at ultra high densities (Q-phase, form a view of asymptotic freedom). Here, as a first step, we try a simple case and discuss the maximum mass of NSs.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2012

Quark confinement due to non-Abelian magnetic monopoles in SU(3) Yang-Mills theory

We present recent results on quark confinement: in SU(3) Yang-Mills theory, confinement of fundamental quarks is obtained due to the dual Meissner effect originated from non-Abelian magnetic monopoles defined in a gauge-invariant way, which is distinct from the well-known Abelian projection scenario. This is achieved by using a non-Abelian Stokes theorem for the Wilson loop operator and a new reformulation of the Yang-Mills theory.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2013

Chiral symmetry, massive gluons and confinement

It is quite difficult to obtain non-trivial chiral symmetry breaking solutions for the quark gap equation in the presence of dynamically generated gluon masses. An effective confining propagator has recently been proposed by Cornwall in order to solve this problem. We study phenomenological consequences of this approach, showing its compatibility with the experimental data. We argue that this confining propagator should be restricted to a small region of momenta, leading to effective four-fermion interactions at low energy.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2013

Light baryon spectroscopy

The spectrum of excited baryons serves as an excellent probe of quantum chromodynamics (QCD). In particular, highly-excited baryon resonances are sensitive to the details of quark confinement which is only poorly understood within QCD. Facilities worldwide such as Jefferson Lab, ELSA, and MAMI, which study the systematics of hadron spectra in photo- and electroproduction experiments, have accumulated a large amount of data in recent years including unpolarized cross section and polarization data for a large variety of meson-production reactions. These are important steps toward complete experiments that will allow us to unambiguously determine the scattering amplitude in the underlying reactions and to identify the broad and overlapping baryon resonance contributions. Several new nucleon resonances have been proposed and changes to the baryon listing in the 2012 Review of Particle Physics reflect the progress in the field.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2014

Physics with charmonium - Highlights of BESIII and PANDA

The physics of the strong interaction is undoubtedly one of the most challenging areas of modern science. Quantum ChromoDynamics (QCD) is reproducing successfully the physics phenomena at distances much shorter than the size of the nucleon, where perturbation theory can be used yielding results of high precision and predictive power. At larger distance scales, however, perturbative methods cannot be applied anymore, although spectacular phenomena, such as the generation of hadron masses and quark confinement, occur. Studies using charmed quarks and gluon-rich matter have the potential to connect the perturbative and the non-perturbative QCD region. The annihilation of matter with antimatter in the mass regime of charmonium is an ideal environment to discover new states or transitions that could reveal the secrets of the strong interaction. Hadronic and electromagnetic transitions between charmonium states and their decays have been measured with a world-record in precision with the BESIII spectrometer at the electron-positron collider at IHEP Beijing, China. Moreover, unconventional narrow charmonium-rich states have been discovered recently in an energy regime above the open-charm threshold, thereby, possibly initiating a new era in charmonium spectroscopy. The near future experiment, PANDA, at the research facility FAIR in Germany, Darmstadt, will exploit the annihilation of cooled anti-protons with protons to perform charmonium spectroscopy with an incredible precision. I will present the most promising results that have been recently obtained with BESIII together with the future perspectives of PANDA in the field of charmonium spectroscopy.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2016

Perfect Abelian dominance of confinement in quark-antiquark potential in SU(3) lattice QCD

In the context of the dual superconductor picture for the confinement mechanism, we study maximally Abelian (MA) projection of quark confinement in SU(3) quenched lattice QCD with 32{sup 4} at β=6.4 (i.e., a ≃ 0.058 fm). We investigate the static quark-antiquark potential V(r), its Abelian part V{sub Abel}(r) and its off-diagonal part V{sub off}(r), respectively, from the on-axis lattice data. As a remarkable fact, we find almost perfect Abelian dominance for quark confinement, i.e., σ{sub Abel} ≃ σ for the string tension, on the fine and large-volume lattice. We find also a nontrivial summation relation of V (r) ≃ V{sub Abel}(r)+V{sub off}(r)

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2016

Study of axial magnetic effect

The Axial Magnetic Effect manifests itself as an equilibrium energy flow of massless fermions induced by the axial (chiral) magnetic field. Here we study the Axial Magnetic Effect in the quenched SU(2) lattice gauge theory with massless overlap fermions at finite temperature. We numerically observe that in the low-temperature hadron phase the effect is absent due to the quark confinement. In the high-temperature deconfinement phase the energy flow is an increasing function of the temperature which reaches the predicted asymptotic T{sup 2} behavior at high temperatures. We find, however, that energy flow is about one order of magnitude lower compared to a theoretical prediction.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2016

Lattice QCD analysis for relation between quark confinement and chiral symmetry breaking

The Polyakov loop and the Dirac modes are connected via a simple analytical relation on the temporally odd-number lattice, where the temporal lattice size is odd with the normal (nontwisted) periodic boundary condition. Using this relation, we investigate the relation between quark confinement and chiral symmetry breaking in QCD. In this paper, we discuss the properties of this analytical relation and numerically investigate each Dirac-mode contribution to the Polyakov loop in both confinement and deconfinement phases at the quenched level. This relation indicates that low-lying Dirac modes have little contribution to the Polyakov loop, and we numerically confirmed this fact. From our analysis, it is suggested that there is no direct one-to-one corresponding between quark confinement and chiral symmetry breaking in QCD. Also, in the confinement phase, we numerically find that there is a new “positive/negative symmetry” in the Dirac-mode matrix elements of link-variable operator which appear in the relation and the Polyakov loop becomes zero because of this symmetry. In the deconfinement phase, this symmetry is broken and the Polyakov loop is non-zero.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2016

Reformulations of the Yang-Mills theory toward quark confinement and mass gap

We propose the reformulations of the SU (N) Yang-Mills theory toward quark confinement and mass gap. In fact, we have given a new framework for reformulating the SU (N) Yang-Mills theory using new field variables. This includes the preceding works given by Cho, Faddeev and Niemi, as a special case called the maximal option in our reformulations. The advantage of our reformulations is that the original non-Abelian gauge field variables can be changed into the new field variables such that one of them called the restricted field gives the dominant contribution to quark confinement in the gauge-independent way. Our reformulations can be combined with the SU (N) extension of the Diakonov-Petrov version of the non-Abelian Stokes theorem for the Wilson loop operator to give a gauge-invariant definition for the magnetic monopole in the SU (N) Yang-Mills theory without the scalar field. In the so-called minimal option, especially, the restricted field is non-Abelian and involves the non-Abelian magnetic monopole with the stability group U (N− 1). This suggests the non-Abelian dual superconductivity picture for quark confinement. This should be compared with the maximal option: the restricted field is Abelian and involves only the Abelian magnetic monopoles with the stability group U(1){sup N−1}, just like the Abelian projection. We give some applications of this reformulation, e.g., the stability for the homogeneous chromomagnetic condensation of the Savvidy type, the large N treatment for deriving the dimensional transmutation and understanding the mass gap, and also the numerical simulations on a lattice which are given by Dr. Shibata in a subsequent talk.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2016

Discriminating between two reformulations of SU(3) Yang-Mills theory on a lattice

In order to investigate quark confinement, we give a new reformulation of the SU (N) Yang-Mills theory on a lattice and present the results of the numerical simulations of the SU (3) Yang-Mills theory on a lattice. The numerical simulations include the derivation of the linear potential for static interquark potential, i.e., non-vanishing string tension, in which the “Abelian” dominance and magnetic monopole dominance are established, confirmation of the dual Meissner effect by measuring the chromoelectric flux tube between quark-antiquark pair, the induced magnetic-monopole current, and the type of dual superconductivity, etc.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2012

Status and plans of the NA61/SHINE physics program

One of the NA61/SHINE experiment's goals is to discover the critical point of strongly interacting matter and study the properties of the onset of deconfinement. This is to be achieved by performing a two-dimensional phase diagram (T- Micro-Sign {sub B}) scan-measuring hadron production in collisions of various beam particles and targets at various beam energies. NA61/SHINE also collects data for the T2K experiment, which are just about to be published.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗