49 Matching Results

Search Results

Advanced search parameters have been applied.
in subjects: "Gluon Model"  
Results: 1 - 24 next
open access

A dynamical {eta}{prime} - mass from an infrared enhanced gluon exchange

Description: The pseudo-scalar flavor-singlet meson mixes with two gluons. A dimensional argument by Kogut and Susskind shows that this can screen the Goldstone pole of the chiral limit in this channel, if the gluon correlations are infrared enhanced. Using a gluon propagator as singular as {sigma}/k{sup 4} for k{sup 2} {yields} 0 we relate the screening mass to the string tension {sigma}. In the Written-Veneziano action to describe the {eta}-{eta}{prime} mixing this relation yields masses of about 810MeV f… more
Date: September 1, 1997
Creator: Smekal, L. von; Mecke, A. & Alkofer, R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Experiments to measure the gluon helicity distribution in protons

Description: Several experiments are described that could obtain information about the gluon helicity distribution in protons. These experiments include inclusive direct-{gamma}, direct-{gamma} + jet, jet, and jet + jet production with colliding beams of longitudinally-polarized protons. Some rates and kinematics are also discussed.
Date: April 1, 1993
Creator: Spinka, H.; Beddo, M. E. & Underwood, D. G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Regge trajectories and the quark-gluon coupling constant

Description: It is argued that vector gluons interacting with quarks produce logarithmic behavior of Regge trajectories at large momentum transfer in agreement with proton-proton scattering data. It is found that g/sup 2//4 pi = 14 where g is the gluonic charge (charm) of the quarks. Some suggestive relations between quark-gluon dynamics, duality magnetic charge and Jacobi's imaginary transformation are discussed. (auth)
Date: January 1, 1973
Creator: Coon, D. D. & Suura, H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Perturbation Theory With Instantons. [Gluon Propagator, Proper Vertex Function]

Description: ''Perturbation theory'' rules are developed for calculating the effect of instantons in a pure Yang-Mills theory with no fermions, in the ''dilute gas'' approximation in which the N-instanton solution is assumed to be the sum of N widely separated one-instanton solutions. These rules are then used to compute the gluon propagator and proper vertex function including all orders of the instanton interaction but only to lowest order in the gluon coupling. It is to be expected that such an approxima… more
Date: May 1977
Creator: Carruthers, P.; Pinsky, S. S. & Zachariasen, F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Measurements of gluon spin-sensitive quantities at the Z{sup 0} resonance

Description: Measurements have been made of the scaled jet energies (x{sub 1}, x{sub 2}, x{sub 3}) and the Ellis-Karliner angle (cos{theta}{sub EK}), which are sensitive to the spill of the gluon, in the 3-jet hadronic events from the e{sup +}e{sup {minus}} annihilation at the Z{sup 0} resonance. The experiment is performed with the SLD detector at the Stanford Linear Accelerator Center (SLAC). The data used in this analysis was collected during the 1992 physics run, which includes 10,252 hadronic Z{sup 0} … more
Date: October 1, 1993
Creator: Fan, C. G.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
open access

Condensation of (G/sub. mu nu. //sup a/)/sup 2/ in quantum chromodynamics

Description: The property of the QCD vacuum is discussed by focusing on the expectation value of the color-singlet composite operator (G/sub ..mu nu..//sup a/)/sup 2/, the square of the gluon field strength tensor. (G/sub ..mu nu..//sup a/)/sup 2/ condenses quite generally without the assumption of dominance of certain configurations. In the true non-perturbative vacuum of QCD, (G/sub ..mu nu..//sup a/)/sup 2/ condenses with positive (magnetic) sign. 1 figure. (RWR)
Date: August 1, 1980
Creator: Kazama, Y.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Evidence for quarks and gluons

Description: The evidence from the experiments of deep inelastic electron and muon scattering and of ..mu.. pair production at high energy that the neutron and proton are made of quarks and gluons is given.
Date: April 1, 1980
Creator: Anderson, H.L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Dryson equations, Ward identities, and the infrared behavior of Yang-Mills theories. [Schwinger-Dyson equations, Slavnov-Taylor identities]

Description: It was shown using the Schwinger-Dyson equations and the Slavnov-Taylor identities of Yang-Mills theory that no inconsistency arises if the gluon propagator behaves like (1/p/sup 2/)/sup 2/ for small p/sup 2/. To see whether the theory actually contains such singular long range behavior, a nonperturbative closed set of equations was formulated by neglecting the transverse parts of GAMMA and GAMMA/sub 4/ in the Schwinger-Dyson equations. This simplification preserves all the symmetries of the th… more
Date: January 1, 1979
Creator: Baker, M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Nonfactorizability of inclusive distributions in perturbative QCD. [Leading algorithms approximation, large-angle gluon correction, transverse momentum]

Description: Inclusive distribution for lepton pair production was studied in QCD in an improved leading logarithms approximation that allows for large angle gluon correction. A formula is derived for arbitrary values of the dilepton transverse momentum. It does not factorize into the generalized Drell--Yan form. 10 references.
Date: August 11, 1978
Creator: Hwa, R. C. & Wosiek, J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Glueball and exotic-meson candidates

Description: The states seen in radiative psi decay at 1440 and 1640 MeV are discussed. It is argued that the former is almost certainly a glueball while the latter is probably either a glueball or a four quark anti ss(anti uu + anti dd) state. The present status and future verification of these assignments is discussed.
Date: September 1, 1981
Creator: Chanowitz, Michael S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Zero-point energy in bag models

Description: The zero-point (Casimir) energy of free vector (gluon) fields confined to a spherical cavity (bag) is computed. With a suitable renormalization the result for eight gluons is E = + 0.51/a. This result is substantially larger than that for a spherical shell (where both interior and exterior modes are present), and so affects Johnson's model of the QCD vacuum. It is also smaller than, and of opposite sign to, the value used in bag model phenomenology, so it will have important implications there.… more
Date: January 1, 1979
Creator: Milton, K.A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Hadronic physics of q anti q light quark mesons, quark molecules and glueballs

Description: A brief introduction reviews the development of QCD and defines quark molecules and glueballs. This review is concerned primarily with u, d, and s quarks, which provide practically all of the cross section connected with hadronic interactions. The following topics form the bulk of the paper: status of quark model classification for conventional u, d, s quark meson states; status of multiquark or quark molecule state predictions and experiments; glueballs and how to find them; and the OZI rule i… more
Date: October 1, 1980
Creator: Lindenbaum, S. J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Prospects for the study of gluonic states at Beijing Electron- Positron Collider (BEPC)

Description: Progress in the study of gluonic states depends crucially on accumulating data samples of order 10/sup 8/ J//psi/ decays, in order to perform complete partial wave analyses of radiative and hadronic J//psi/ decays. This requirement is well matched to the capabilities of the Beijing Electron-Positron Collider, which has approached the necessary luminosity in its first two months of operation. 28 refs., 1 fig., 1 tab.
Date: January 11, 1989
Creator: Chanowitz, Michael S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Review of meson spectroscopy: quark states and glueballs

Description: A group of three lectures on hadron spectroscopy are presented. Topics covered include: light L = 0 mesons, light L = 1 mesons, antiquark antiquark quark quark exotics, a catalogue of higher quark antiquark excitations, heavy quarkonium, and glueballs. (GHT)
Date: November 1, 1981
Creator: Chanowitz, Michael S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Topics in the theory of heavy-quark systems

Description: Due to the kinematic and dynamic simplifications possible because of the large mass of heavy quark bound states, certain properties of these systems can be quantitatively analyzed within the framework of quantum chromodynamics. It is clear that dimensionally the size of the bound state is proportional to the inverse quark mass, and for very heavy quarkonia the radius of the system should become smaller than that of normal hadrons. When this small system interacts with external long wavelength f… more
Date: April 1, 1981
Creator: Flory, C.A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

QCD, OZI, and evidence for glueballs

Description: The characteristics expected from low Q-QCD for the behavior of glueballs and the OZI rule is discussed. The reaction ..pi../sup -/p ..-->.. phi phi n represents on OZI forbidden (hairpin) diagram. It has been observed at the Brookhaven National Laboratory multiparticle spectrometer by the Brookhaven National Laboratory/City College of New York group. The author has shown that the expected OZI suppression is essentially entirely absent and in fact the Isobar Model which does not contain OZI sup… more
Date: January 1, 1981
Creator: Lindenbaum, S. J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Soft-gluon effects in charmed-meson decays

Description: In D/sup 0/- and F/sup +/-meson decays, QCD effects are expected to activate W-exchange processes (quark-annihilation processes), as shown in Figs. 2 and 3, which by themselves are strongly suppressed because of helicity mismatch. For example, the D/sup 0/ meson, on gluon emission, can flip its spin so that the subsequent weak decay proceeds without helicity suppression. Hard-gluon emission from the D/sup 0/ meson, evaluated perturbatively, enhances the D/sup 0/ decay rate (by approx. 20%). Sof… more
Date: June 1, 1981
Creator: Shizuya, K.I
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
Back to Top of Screen