2,010 Matching Results

Search Results

Advanced search parameters have been applied.

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

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

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

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

Integrated system for production of neutronics and photonics calculational constants. Neutron-induced interactions: bibliography of experimental data

Description: The bibliographic citations in the Experimental Cross Section Information Library (ECSIL) as of July 4, 1976 are tabulated. The tabulation has three arrangements: alphabetically by author, alphabetically by publication, and numerically by reference number.
Date: July 4, 1976
Creator: MacGregor, M. H.; Cullen, D. E.; Howerton, R. J. & Perkins, S. T.
Partner: UNT Libraries Government Documents Department

Integrated system for production of neutronics and photonics calculational constants. Supplemental neutron-induced interactions (Z less than or equal to 35): graphical, experimental data

Description: This report (Vol. 8) presents graphs of supplemental neutron-induced cross sections in the Experimental Cross Section Information Library (ECSIL) as of July 4, 1976. It consists of interactions where more than one data set is needed to show cross-section behavior. In contrast, Vol. 7 of this UCRL-50400 series consists primarily of interactions where a single data set contains enough points to show cross-section behavior. In Vol. 7 can be found the total, elastic, capture, and fission cross sections (along with the parameters anti ..nu.., ..cap alpha.., and eta). Volume 8 contains all other reactions. Data are plotted with associated cross-section error bars (when given) and compared with the Evaluated Nuclear Data Library (ENDL) as of July 4, 1976. The plots are arranged in ascending order of atomic number (Z) and atomic weight (A). Part A contains the plots for Z = 1 to 35; Part B contains the plots for Z greater than 35.
Date: July 4, 1976
Creator: Cullen, D. E.; Howerton, R. J.; MacGregor, M. H. & Perkins, S. T.
Partner: UNT Libraries Government Documents Department

Integrated system for production of neutronics and photonics calculational constants. Volume 15, Part C. The LLL Evaluated Nuclear Data Library (ENDL): translation of ENDL neutron-induced interaction data into the ENDF/B format

Description: The LLL evaluated nuclear data library (ENDL) has been translated into the evaluated neutron data file/version B (ENDF/B) format. This translation is for the convenience of those who wish to use ENDL data but who are more familiar with ENDF/B formats and procedures. Only that portion of ENDL dealing with neutron-induced interactions (including photon production from neutron-induced reactions) has been translated.
Date: April 1, 1976
Creator: Howerton, R. J.
Partner: UNT Libraries Government Documents Department

Integrated system for production of neutronics and photonics calculational constants. Neutron-induced interactions: index of experimental data

Description: Indexes to the neutron-induced interaction data in the Experimental Cross Section Information Library (ECSIL) as of July 4, 1976 are tabulated. The tabulation has two arrangements: isotope (ZA) order and reaction-number order.
Date: July 4, 1976
Creator: MacGregor, M. H.; Cullen, D. E.; Howerton, R. J. & Perkins, S. T.
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

Neutron Physics Division progress report for period ending February 28, 1977

Description: Summaries are given of research progress in the following areas: (1) measurements of cross sections and related quantities, (2) cross section evaluations and theory, (3) cross section processing, testing, and sensitivity analysis, (4) integral experiments and their analyses, (5) development of methods for shield and reactor analyses, (6) analyses for specific systems or applications, and (7) information analysis and distribution. (SDF)
Date: May 1, 1977
Creator: Maienschein, F. C.
Partner: UNT Libraries Government Documents Department

Analysis of the sensitivity of spectrum-average cross sections to individual characteristics of differential excitation functions

Description: A simple procedure for analyzing the sensitivity of computed spectrum-average cross sections to detailed properties of excitation functions for threshold nuclear reactions commonly used in reactor dosimetry is described. This procedure is shown to be useful in identifying specific needs for improved differential data and as a tool to be employed in performing evaluations. Several examples are presented to illustrate the subject matter.
Date: March 1, 1977
Creator: Smith, D. 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

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

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

K-meson experiments

Description: This paper presents a brief review of the status of K-meson interactions with nuclei. Emphasis is placed on 1s shell nuclei with representative examples drawn from experiments on heavier nuclear systems. Directions for future developments are discussed.
Date: January 1, 1980
Creator: Hungerford, E.V.
Partner: UNT Libraries Government Documents Department

Nuclear data requirements for fusion reactor nucleonics

Description: Nuclear data requirements for fusion reactor nucleonics are reviewed and the present status of data are assessed. The discussion is divided into broad categories dealing with data for Fusion Materials Irradiation Test Facility (FMIT), D-T Fusion Reactors, Alternate Fuel Cycles and the Evaluated Data Files that are available or would be available in the near future.
Date: January 1, 1980
Creator: Bhat, M.R. & Abdou, M.A.
Partner: UNT Libraries Government Documents Department

Review on DTU-parton model for hadron-hadron and hadron-nucleus collisions

Description: The parton picture of color separation of dual string and its subsequent breakup is used to motivate the DTU-parton model for high energy small p/sub T/ multiparticle productions in hadron-hadron and hadron-nucleus collisions. A brief survey on phenomenological applications of the model: such as the inclusive spectra for various hh processes and central plateau heights predicted, hA inclusive spectra and the approximate anti v-universalities is presented.
Date: August 1, 1980
Creator: Chiu, C.B.
Partner: UNT Libraries Government Documents Department

Critical radius and critical number of gas atoms for cavities containing a Van der Waals gas

Description: The effect of gas on void nucleation and growth is particularly important for structural materials in fusion reactors because of the high production of helium by neutron-induced transmutation reactions. Gas reduces the critical radius for bias driven growth and there is a critical number of gas atoms, n/sub g/*, at which the critical radius is reduced essentially to zero. The significance of this is that the time interval to the accumulation of n/sub g/* gas atoms may determine the time to the onset of bias driven swelling where n/sub g/* is large. In previous papers these critical quantities were given for an ideal gas. Recently, we presented the results for a Van der Waals gas. Here the derivation of these relations is presented and further results of calculations are given. At low temperatures (high pressures) the results depart from those of the ideal gas, with the critical number affected more strongly than the critical radius. Comparisons are made with earlier calculations.
Date: January 1, 1983
Creator: Coghlan, W.A. & Mansur, L.K.
Partner: UNT Libraries Government Documents Department

Nuclear structure studies at intermediate energies. Annual progress report, November 1979-October 1980. [Univ. of Minnesota, 11/79-10/80]

Description: Research during the period November 1979 through October 1980 is reported. Completed work will be published in the usual places. Three sections containing significant amounts of information are abstracted separately. (RWR)
Date: January 1, 1980
Creator: Hintz, N. M.; Franey, M. A.; Gazzaly, M.; Cook, D.; Owen, K. & Overacker, L.
Partner: UNT Libraries Government Documents Department