1,360 research outputs found
Test of the Skyrme Effective Field Theory Using Quenched Lattice QCD
The Skyrme effective field theory is tested by evaluating nucleon ground
state matrix elements of the correlation functions for two flavor density
operators and two pseudoscalar density operators in the Skyrme model and
comparing them with results in quenched lattice QCD. The possiblility of using
quenched lattice QCD to study higher-order terms in effective field theory is
also discussed.Comment: 20 pages in TeX, 6 figures added using "figures", MIT-CTP-200
Insight into the Role of Instantons and their Zero Modes from Lattice QCD
Evidence from lattice QCD calculations is presented showing that instantons
and their associated zero modes play a major role in the physics of light
hadrons and the propagation of light quarks in the QCD vacuum.Comment: Proceedings of KEK Tanashi Symposium. 8 pages LaTe
Bijective Proofs of Gould's and Rothe's Identities
We first give a bijective proof of Gould's identity in the model of binary
words. Then we deduce Rothe's identity from Gould's identity again by a
bijection, which also leads to a double-sum extension of the
-Chu-Vandermonde formula.Comment: 4 page
Instanton Distribution in Quenched and Full QCD
In order to optimize cooling as a technique to study the instanton content of
the QCD vacuum, we have studied the effects of alternative algorithms, improved
actions and boundary conditions on the evolution of single instantons and
instanton anti-instanton pairs. Using these results, we have extracted and
compared the instanton content of quenched and full QCD.Comment: 3 pages, LaTeX file + 3 figures included, uses epsfig.sty and
espcrc2.sty. Talk presented at LATTICE96(topology
Study of Instanton Contributions to Moments of Nucleon Spin-Dependent Structure Functions
Instantons are the natural mechanism in non-perturbative QCD to remove
helicity from valence quarks and transfer it to gluons and quark-antiquark
pairs. To understand the extent to which instantons explain the so-called "spin
crisis" in the nucleon, we calculate moments of spin-dependent structure
functions in quenched QCD and compare them with the results obtained with
cooled configurations from which essentially all gluon contributions except
instantons have been removed. Preliminary results are presented.Comment: LATTICE98(matrixelement), 3 pages, 1 figur
Land and water management in coastal zones: Dealing with agriculture-aquaculture-fishery conflicts
Social and environmental impact of rapid change in the coastal zone of Vietnam: An assessment of sustainability issues
Instantons, the QCD Vacuum, and Hadronic Physics
A large body of evidence from lattice calculations indicates that instantons
play a major role in the physics of light hadrons. This evidence is summarized,
and recent results concerning the instanton content of the SU(3) vacuum,
instanton contributions to the static potential, and a new class of instanton
solutions at finite temperature are reviewed.Comment: 13 pages, 8 figures, Latex using Boxed EPS Macros, LATTICE98 Plenary
Tal
Evidence for Possible Phase-Separations in RuSr2(Gd,Ce)2Cu2O10-delta
An unusual thermal-magnetic hysteresis was observed between a minor magnetic
transition around 120 K and the main one at 80 K in superconducting
RuSr2(R,Ce)2Cu2O10-delta (Ru1222R) samples, where R = Gd or Eu, down to a
submicron length-scale. The observation suggests a possible phase-separation
and is consistent with the very small but universal demagnetizing factor
observed, which is difficult to reconcile with the canted spin-structure
previously proposed. In such a scenario, the unusual superconducting properties
of the Ru-based cuprates can also be understood naturally.Comment: 8 pages, 3 figures, submitted to Phys. Rev. B, "Rapid Communications"
(September 26, 2001
30 Doradus - a Template for "Real Starbursts"?
30 Doradus is the closest massive star forming region and the best studied
template of a starburst. In this conference paper we first summarize the
properties of 30 Doradus and its stellar core, R136. We discuss the effects of
insufficient spatial resolution and cluster density profiles on dynamical mass
estimates of super star clusters, and show that their masses can be easily
overestimated by a factor of ten or more. From a very simple model, with
R136-like clusters as representative building blocks, we estimate typical
luminosities of the order 10^11 L_o for starburst galaxies.Comment: To be published in "Starbursts: From 30 Doradus to Lyman Break
Galaxies", eds. R. de Grijs & R.M. Gonzalez Delgad
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