1,718 Matching Results

Search Results

Advanced search parameters have been applied.

Search for Mu's K(0)'s or Characteristic Hadron Signatures and Masses in Coincidence with Single Directly Produced Electrons

Description: The authors propose to investigate the anomalous production of leptons in hadron reactions using the FNAL cyclotron magnet facility in conjunction with a direct electron trigger. The large aperture of the magnet plus the existing detector array will make it possible to study the topology of the anomalous events for distinctive signatures such as invariant mass peaks or accompanying {mu}'s or K{sup o}'s. The use of an electron trigger instead of a muon trigger allows better offline noise suppression as well as overall event reconstructability.
Date: January 1, 1975
Creator: Barton, D.; Bolon, C.; Brandenburg, G.; Butler, J.; Busza, W.; Fiedman, J. et al.
Partner: UNT Libraries Government Documents Department

Some highlights of the recent Fermilab Fixed Target Program of interest to the nuclear physics community

Description: Many of the high energy physics questions addressed by the Fermilab Fixed Target Experiments are also of interest to the members of the nuclear community. Some recent highlights of the program, including studies of A-dependence of cross sections, evidence for parton rescattering in nuclear media, studies of heavy quark production, evidence for color transparency, and insights into QCD from meson systems, are discussed.
Date: February 1, 1995
Creator: Conrad, J.; Papavassiliou, V. & Zielinski, M.
Partner: UNT Libraries Government Documents Department

L Polarization in Unpolarized Hadron Reactions.

Description: The transverse polarization observed in the inclusive production of {Lambda} hyperons in the high energy collisions of unpolarized hadrons is tackled by considering a new set of spin and {kappa}{perpendicular} dependent quark fragmentation functions. Simple phenomenological expressions for these new ''polarizing fragmentation functions'' are obtained by a fit of the data on {Lambda}'s and {bar {Lambda}}'s produced in p - N processes.
Date: April 23, 2001
Creator: Anselmino, M.; Boer, D.; Dalesio, U. & Murgia, F.
Partner: UNT Libraries Government Documents Department

Threshold resummation of soft gluons in hadronic reactions - an introduction.

Description: The authors discuss the motivation for resummation of the effects of initial-state soft gluon radiation, to all orders in the strong coupling strength, for processes in which the near-threshold region in the partonic subenergy is important. The author summarizes the method of perturbative resummation and its application to the calculation of the total cross section for top quark production at hadron colliders. Comments are included on the differences between the treatment of subleading logarithmic terms in this method and in other approaches.
Date: February 17, 1998
Creator: Berger, E. L.
Partner: UNT Libraries Government Documents Department

Large equipment and facilities

Description: Component and design criteria are reviewed for a general purpose modular multiparticle spectrometer system. The study of hadronic interactions is emphasized, although the solenoidal magnet vertex detector system can be used for W bosons and other weak interaction processes. A general purpose spectrometer seems compatible with the requirements of the ISABELLE straight sections. (auth)
Date: January 1, 1975
Creator: Louttit, R.; Love, W. & Lindenbaum, S.J.
Partner: UNT Libraries Government Documents Department

The BRAHMS experiment at RHIC

Description: The BRAHMS experiment is designed to measure semi-inclusive spectra of charged hadrons over a wide range of rapidity. It will yield information on particle production, both at central rapidity and in the baryon rich fragmentation region. Examples of measurements for soft as well as for hard physics are presented.
Date: December 31, 1996
Creator: Videbaek, F.
Partner: UNT Libraries Government Documents Department

Processing needs and constraints: neutron data processing

Description: New applications for processed data and increased accuracy requirements have generated needs for change in the Evaluated Nuclear Data Files (ENDF). Some constraints must be removed to allow this growth to take place, but other strong constraints must remain to protect existing users.
Date: January 1, 1980
Creator: MacFarlane, R.E.
Partner: UNT Libraries Government Documents Department

Evaluating fission neutron-multiplicity data

Description: The present work had its origins in the practical need to obtain P[sub [nu]] for the purpose of calculating the theoretical response of instrumentation that used a correlation technique to assay spontaneously fissioning nuclides. The assay results are proportional to the factorial moments calculated with the P[sub [nu]] distribution. Obtaining experimentally derived sets of P[sub [nu]] from many sources reported over several decades led immediately to the problem of evaluating the data: Aside from the trivial problem of sometimes not being properly normalized, the first moments ([nu]) = ([nu]) = [Sigma][nu]P[sub [nu]] were typically not in accord with the best recent evaluations, or the calibration of detector efficiency was based on obsolete values for ([nu]) for supposedly well-characterized standard'' nuclides such as [sup 252]Cf. The problem of evaluating P[sub [nu]] is unusual in that, compared to the usual situation where the quantities being evaluated are single numbers, the P[sub [nu]] are sets of numbers, that moreover, are constrained so that [Sigma]P[sub [nu]][triple bond] 1 and [Sigma][nu] P[sub [nu]] = ([nu]), where ([nu]) is usually determined more accurately from a separate experiment than it can be calculated from the experimentally derived P[sub [nu]] distribution.
Date: January 1, 1992
Creator: Zucker, M.S. & Holden, N.E.
Partner: UNT Libraries Government Documents Department

Nuclear physics in the 10 to 300 MeV energy range using a pulsed white neutron source

Description: A new pulsed white neutron source is under construction at the Los Alamos WNR facility. The neutrons are produced by LAMPF proton micropulses striking thick targets of various materials. Beam parameters include energy of 800 MeV, pulse rate of approximately 50,000 Hz, 0.4 nsec pulse width, average current as high as 6..mu..a, and a useful neutron energy range from 3 to 300 MeV. The facility will receive beam approximately 80% of the time LAMPF is operational; it increased by a factor of 1000 the experimental capability over the present system at the WNR when beam intensity, angular distribution, and availability are taken into account. In addition to established white source techniques, the facility is also highly competitive with monoenergetic sources for a wide class of experiments such as neutron capture ..gamma.. ray spectroscopy and neutron-induced charged particle reactions. The facility should be operational in about nine months. Arrangements are underway to make the facility readily accessible to visiting experimenters.
Date: January 1, 1984
Creator: Bowman, C.D.; Wender, S.A. & Auchampaugh, G.F.
Partner: UNT Libraries Government Documents Department

Testing quantum chromodynamics

Description: The difficulties in isolating specific QCD mechanisms which control hadronic phenomena, and the complications in obtaining quantitative tests of QCD are discussed. A number of novel QCD effects are reviewed, including heavy quark and higher twist phenomena, initial and final state interactions, direct processes, multiparticle collisions, color filtering, and nuclear target effects. The importance of understanding hadron production at the amplitude level is stressed.
Date: September 1, 1982
Creator: Brodsky, S.J.
Partner: UNT Libraries Government Documents Department

High energy hadron-nucleus scattering

Description: Theoretical expectations for hadron-nucleus scattering at high energy if the basic hadron-hadron interaction is due to Regge poles and cuts arising in multiperipheral or soft field theory models are described. Experiments at Fermilab may provide a critical test of such models. (auth)
Date: January 1, 1975
Creator: Koplik, J. & Mueller, A.H.
Partner: UNT Libraries Government Documents Department

Charge exchange probes of nuclear structure and interactions with emphasis on (p,n)

Description: New results from (p,n) studies at IUCF show that it is possible to observe Gamow-Teller (GT) strength and extract GT matrix elements from (p,n) measurements. The charge exchange reactions (/sup 6/Li,/sup 6/He) and (..pi../sup +/,..pi../sup 0/) involve different projectile quantum numbers, and the relationships of these reactions to (p,n) is discussed.
Date: January 1, 1980
Creator: Goodman, C.D.
Partner: UNT Libraries Government Documents Department

150-m measurement of 0. 880- to 100. 0-keV neutron transmissions through four samples of /sup 238/U

Description: In order to study the /sup 238/U + n total cross section, neutron transmissions through 0.076-, 0.254-, 1.080-, and 3.620-cm-thick samples of isotopically enriched /sup 238/U have been measured from 0.880 to 100.0 keV using a time-of-flight technique over a path length of 150 meters with the ORELA pulsed source and a 13-mm-thick Li-glass detector. The measurement is described in detail and both a listing and figures of the resulting transmissions are given. An absolute energy scale accurate to 2 parts in 10,000 was established.
Date: October 1, 1977
Creator: Olsen, D. K.; de Saussure, G.; Perez, R. B.; Difilippo, F. C.; Ingle, R. W. & Weaver, H.
Partner: UNT Libraries Government Documents Department

Analysis of neutron data in the resonance region via the computer code SAMMY

Description: Procedures for analysis of resonance neutron cross-section data have been implemented in a state-of-the-art computer code SAMMY, developed at the Oak Ridge Electron Linear Accelerator (ORELA) at Oak Ridge National Laboratory. A unique feature of SAMMY is the use of Bayes' equations to determine ''best'' values of parameters, which permits sequential analysis of data sets (or subsets) while giving the same results as would be given by a simultaneous analysis. Another important feature is the inclusion of data-reduction parameters in the fitting procedure. Other features of SAMMY are also described.
Date: January 1, 1985
Creator: Larson, N.M.
Partner: UNT Libraries Government Documents Department

Nuclear structure theory. Annual technical progress report, October 1, 1976--September 30, 1977. [Research progress at the University of Rochester]

Description: This report summarizes progress during the past year in the following areas of nuclear structure and reaction theory: (1) statistical spectroscopy, including giant resonances for beta and electromagnetic excitation and sum rules (including inverse-energy-weighted sum rules), statistical methods of truncating shell model spaces and renormalization of operators, study of state labelling and ''chains'' of groups, evaluation of fluctuation measures, technical aspects of operator averaging; (2) meson interactions with nuclei, including scattering and absorption of mesons by nuclei (general methods), models for absorption, single- and double-charge exchange of pions, role of rho mesons.
Date: January 1, 1977
Creator: French, J.B. & Koltun, D.S.
Partner: UNT Libraries Government Documents Department

Theoretical studies in nuclear reaction and nuclear structure. Final report, January 1, 1975--June 30, 1976

Description: Progress in theoretical research is reported under the following readings: (1) few nuclear reactions, Eikonal approximations, and optical models; (2) pion reactions; (3) nuclear structure by reaction studies; (4) nuclear dynamics. (SDF)
Date: July 1, 1977
Creator: Banerjee, M. K. & Griffin, J. J.
Partner: UNT Libraries Government Documents Department

Consistency of differential and integral thermonuclear neutronics data

Description: To increase the accuracy of the neutronics analysis of nuclear reactors, physicists and engineers have employed a variety of techniques, including the adjustment of multigroup differential data to improve consistency with integral data. Of the various adjustment strategies, a generalized least-squares procedure which adjusts the combined differential and integral data can significantly improve the accuracy of neutronics calculations compared to calculations employing only differential data. This investigation analyzes 14 MeV neutron-driven integral experiments, using a more extensively developed methodology and a newly developed computer code, to extend the domain of adjustment from the energy range of fission reactors to the energy range of fusion reactors.
Date: January 1, 1978
Creator: Reupke, W.A.
Partner: UNT Libraries Government Documents Department

Use of R-matrix methods for light element evaluations

Description: Some general aspects of parameterizing nuclear reaction data with a unitary, multichannel theory are discussed. The special case of R-matrix theory are discussed. The special case of R-matrix theory is considered, where the explicit separation of long- and short-range forces and the natural occurrence of energy pole terms afford a number of advantages in describing data for light-element reactions. Examples are given for both neutron- and charged-particle-induced reactions which illustrate multichannel R-matrix techniques, including the use of charge symmetry to relate data for mirror systems. The limitations of conventional R-matrix methods are discussed briefly.
Date: January 1, 1980
Creator: Hale, G.M.
Partner: UNT Libraries Government Documents Department

Nuclear data and related services

Description: National Nuclear Data Center (NNDC) maintains a number of data bases containing bibliographic information and evaluated as well as experimental nuclear properties. An evaluated computer file maintained by the NNDC, called the Evaluated Nuclear Structure Data File (ENSDF), contains nuclear structure information for all known nuclides. The ENSDF is the source for the journal ''Nuclear Data Sheets'' which is produced and edited by NNDC. The Evaluated Nuclear Data File (ENDF), on the other hand is designed for storage and retrieval of such evaluated nuclear data as are used in neutronic, photonic, and decay heat calculations in a large variety of applications. Some of the publications from these data bases are the Nuclear Wallet Cards, Radioactivity Handbook, and books on neutron cross sections and resonance parameters. In addition, the NNDC maintains three bibliographic files: NSR - for nuclear structure and decay data related references, CINDA - a bibliographic file for neutron induced reactions, and CPBIB - for charged particle reactions. Selected retrievals from evaluated data and bibliographic files are possible on-line or on request from NNDC. 6 refs., 1 fig.
Date: January 1, 1985
Creator: Tuli, J.K.
Partner: UNT Libraries Government Documents Department

Excitation of giant resonances via direct reactions

Description: Experimental measurements of electric giant multipole resonances are discussed. The parameters of the giant quadrupole resonance are now firmly established by an extensive set of measurements. The GQR is providing a significant influence in other areas of nuclear physics. The monopole resonance has now been established and its observation has provided the first direct measure of the nuclear compressibility. A strong case for the existence of a giant octupole resonance is now being made through a variety of hadron reactions. However, the supply of giant multipole resonances has not been exhausted. The newer techniques such as higher energy proton scattering, charge exchange reactions, heavy-ion scattering and pion reactions offer considerable hope for identifying new resonances during the next few years.
Date: January 1, 1982
Creator: Bertrand, F.E.
Partner: UNT Libraries Government Documents Department

Theoretical studies in nuclear reaction and nuclear structure. Progress report, March 1, 1976--August 31, 1977. [Summary of research progress at the University of Maryland]

Description: This progress report is divided into five sections covering Many-Body and Few-Body Reaction Theory, Intermediate Energy Reactions, Pion Reactions, and Nuclear Dynamics describing recent progress on thirty-five specific topics. In addition, Appendices list the publications (44), invited (13) and contributed (36) papers of the research group since March, 1976.
Date: January 1, 1977
Creator: Griffin, J. J. & Banerjee, M. K.
Partner: UNT Libraries Government Documents Department

Nuclear structure theory. Annual technical progress report, October 1, 1979-August 31, 1980. [Univ. of Rochester]

Description: This report summarizes progress during the past year in the following areas of nuclear structure and reaction theory: statistical spectroscopy (including random matrix methods, with applications to fluctuations in spectra and in strength distributions, and to problems of ergodicity; group symmetries in spectral-distribution theory; electromagnetic and ..beta.. transitions); meson scattering and absorption by nuclei (including general scattering theory with absorption, multiple scattering theory and its reactive content, statistical theory of absorption); and meson currents in electromagnetic transitions.
Date: January 1, 1980
Creator: French, J.B. & Koltun, D.S.
Partner: UNT Libraries Government Documents Department