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Missing Mass Spectra from p p ---> p X from 9-GeV/c to 300-GeV/c

Description: Missing mass spectra were obtained by measuring recoil protons from the reaction p + p {yields} p + X in the Jacobian peak region at |t| = 0.175 and 0.25 (GeV/c){sup 2}. The incident momentum range from 9 to 300 GeV/c was covered continuously by taking data during the acceleration ramp of the Fermi National Accelerator Laboratory machine. Our missing mass range varied from 1.5 to 8.5 GeV and we observed the well known N*(1688) and N*(2l90) but no significant structures at higher mass.
Date: June 1, 1974
Creator: Abe, K.; Alspector, J.; Bomberowitz, R.; Cohen, K.J.; De Lillo, T.; Harrison, W.C. et al.
Partner: UNT Libraries Government Documents Department

Hyperon-nucleon bound states and electroproduction of strangeness on light nuclei.

Description: The A(e,e{prime}K{sup +})Y X reaction has been investigated in Hall C at Jefferson Lab. Data were taken for Q{sup 2} {approx} 0.35 and 0.5 GeV{sup 2} at a beam energy of 3.245 GeV for {sup 1}H, {sup 2}H, {sup 3}He and {sup 4}He, C and Al targets. The missing mass spectra are fitted with Monte Carlo simulations including {Lambda}, {Sigma}{sup 0}, {Sigma}{sup -} hyperon production. Models for quasifree production are compared to the data, excess yields close to threshold are attributed to FSI. Evidence for {Lambda}-hypernuclear bound states is seen for {sup 3,4}He targets.
Date: June 25, 2002
Creator: Dohrmann, F.; Abbott, D.; Ahmidouch, A.; Ambrozewicz, P.; Armstrong, C. S.; Arrington, J. et al.
Partner: UNT Libraries Government Documents Department

SEARCH FOR NUCLEI CONTAINING TWO STRANGE QUARKS.

Description: This paper discusses a search for nuclei containing two strange quarks performed at Brookhaven National Laboratory. The goals and approach of experiment E885 are reviewed. Preliminary missing mass spectra for a subset of the data are presented, showing sensitivity for {Xi} hypernuclei and H particle searches. Existence of an angular correlation between pions in the sequential decay of {Lambda}{Lambda} hypernuclei is suggested on theoretical grounds.
Date: October 13, 1997
Creator: MAY,M.
Partner: UNT Libraries Government Documents Department

Electroproduction of strangeness on light nuclei.

Description: The A(e,e{prime} K{sup +})YX reaction has been investigated in Hall C at Jefferson Laboratory for 6 different targets. Data were taken for Q{sup 2} {approx} 0.35 and 0.5 GeV{sup 2} at a beam energy of 3.245 GeV for {sup 1}H, {sup 2}H, {sup 3}He, {sup 4}He, C and Al targets. The missing mass spectra are fitted with Monte Carlo simulations taking into account the production of {Lambda} and {Sigma}{sup 0} hyperon production off the proton, and {Sigma}{sup -} off the neutron. Models for quasifree production are compared to the data, excess yields close to threshold are attributed to FSI. Evidence for {Lambda}-hypernuclear bound states is seen for {sup 3,4}He targets.
Date: May 16, 2002
Creator: Dohrmann, F.; Abbott, D.; Ahmidouch, A.; Ambrozewicz, P.; Armstrong, C. S.; Arrington, J. et al.
Partner: UNT Libraries Government Documents Department

A proposal to study inelastic diffractive processes by observing coherent production of multipion final states from He nuclei

Description: We propose to study the diffraction dissociation of pions into multi-pion final states, by obtaining the missing mass spectra from the reaction: {pi}{sup -} + He {yields} n{pi}{sup -} + (n - 1){pi}{sup +} + He. The missing mass is calculated from a measurement of the he recoil which is observed in a streamer chamber. In this first exploratory experiment we propose to count the outgoing fast particles, and to measure in a very crude fashion their momenta.
Date: July 1, 1970
Creator: Bastien, P.L.; Cook, V.; Kenyon, R.; Kirkpatrick, L.D.; Lubatti, H.J.; Wolfe, D. et al.
Partner: UNT Libraries Government Documents Department

Electroproduction of Kaons on light nuclei.

Description: The A(e,e{prime}K{sup +})YX reaction on H, D, {sup 3}He, and {sup 4}He was investigated in Hall C at CEBAF. Data were obtained for Q{sup 2} {approx} 0.35 and 0.5 GeV{sup 2} at 3.245 GeV. The missing mass spectra for both H and D are fitted with Monte-Carlo simulations incorporating peaks corresponding to {Lambda} production on the proton and {Sigma} production on both the proton and neutron. For D, the cross section ratio {Sigma}{sup 0}/{Sigma}{sup {minus}} {approx} 2, and excess yield close to the thresholds for {Lambda} and {Sigma} production can be attributed to final-state interactions that are compared to the data. The analysis of the data for the He targets is in a more preliminary state with broader quasi-free peaks resulting from the higher Fermi momenta. Evidence for bound {Lambda}-hypernuclear states is seen and other structure may be present.
Date: December 7, 2000
Creator: Zeidman, B.; Abbott, D.; Ahmidouch, A.; Ambrozewicz, P.; Armstrong, C. S.; Arrington, J. et al.
Partner: UNT Libraries Government Documents Department

Double semi-leptonic charm decay in helios-I 450 GeV/c p-Be data. Appendix 1

Description: Data taken in 1989 by HELIOS-I (NA34) at the CERN SPS (450 GeV/c proton beam on Be target) have been examined for e{sup {plus_minus}} {mu}{sup {minus_plus}} or {mu}{sup {plus_minus}} {mu}{sup {minus_plus}} pairs with associated missing energy. Such pairs arise from semi-leptonic decay of both members of a c{bar c} pair. The e{mu} and {mu}{mu} samples are consistent with expectations from charm decay, allowing a quantitative limit to be placed on other physics.
Date: December 31, 1992
Creator: Pierre, A. & Pomianowski, P. A.
Partner: UNT Libraries Government Documents Department

rvec p + sup 13 rvec C elastic scattering at 500 MeV

Description: For the first time, an elastic scattering experiment was performed at LAMPF using polarized protons and a polarized target nucleus ({rvec p} + {sup 13}{rvec C}). The analyzing powers (A{sub ooon}({Theta})) and (A{sub oonn}({Theta})) were measured using an incident beam energy of 500 MeV over the laboratory angular range of 10{degree}--30{degree}. Motivation for the experiment and some preliminary results and conclusions are presented. 12 refs., 7 figs.
Date: January 1, 1990
Creator: Tanaka, N.
Partner: UNT Libraries Government Documents Department

Double semi-leptonic charm decay in helios-I 450 GeV/c p-Be data

Description: Data taken in 1989 by HELIOS-I (NA34) at the CERN SPS (450 GeV/c proton beam on Be target) have been examined for e[sup [plus minus]] [mu][sup [minus plus]] or [mu][sup [plus minus]] [mu][sup [minus plus]] pairs with associated missing energy. Such pairs arise from semi-leptonic decay of both members of a c[bar c] pair. The e[mu] and [mu][mu] samples are consistent with expectations from charm decay, allowing a quantitative limit to be placed on other physics.
Date: January 1, 1992
Creator: Pierre, A. (Montreal Univ., PQ (Canada). Dept. of Physics) & Pomianowski, P.A. (Pittsburgh Univ., PA (United States). Dept. of Physics)
Partner: UNT Libraries Government Documents Department

Partial wave analysis of K anti K pi system in the D and E/iota regions

Description: We have performed a partial-wave analysis of the K/sup +/ anti K/sup 0/..pi../sup -/ system produced in the reaction ..pi../sup -/p ..-->.. K/sup +/ anti K/sup 0/..pi../sup -/n at 8.0 GeV/c. We find that the D(1285) is a J/sup PG/ = 1/sup + +/ state coupling predominantly to a delta..pi.. decay channel, while the E(1420) peak consists mostly of a J/sup PG/ = 0/sup - +/ wave with a substantial delta..pi.. decay mode. There is little evidence of a 1/sup + +/ resonance at the E mass.
Date: January 1, 1985
Creator: Chung, S.U.; Fernow, R.; Kirk, H.; Protopopescu, S.D.; Weygand, D.P.; Boehnlein, D. et al.
Partner: UNT Libraries Government Documents Department

Summary of S = 0 dibaryon resonances and candidates

Description: Experimental data concerning S = O dibaryon resonances are reviewed, with an emphasis on the nucleon-nucelon system. Structures observed in the ..gamma..d channel, the ..pi..d elastic scattering, pp ..-->.. ..pi..d channel, and other channels are discussed. Experimental data are compared with various theories. The short-range forces can be represented by dibaryon resonances. Further measurements to clarify the understanding of dibaryons are also discussed. 53 refs., 24 figs.
Date: April 18, 1985
Creator: Yokosawa, A.
Partner: UNT Libraries Government Documents Department

Hard quark-quark scattering with exclusive reactions

Description: We present data from ..pi../sup -/p ..-->.. elastic and rho/sup -/p final states for scattering at 90/sup 0/ center of mass, -t = 9 GeV/sup 2//c/sup 2/. A large rho/sup -/p signal is seen and the rho/sup -/ is strongly polarized. This polarization tests a QCD prediction that quarks cannot flip helicity. The test fails dramatically. 9 references, 4 figures.
Date: January 1, 1984
Creator: Barton, D.S.; Bunce, G.M.; Carroll, A.S.; Makdisi, Y.I.; Baller, B.; Blazey, G.C. et al.
Partner: UNT Libraries Government Documents Department

Low-energy pion double charge exchange and nucleon-nucleon correlations in nuclei

Description: Recent measurements of pion double-charge exchange (DCX) at energies 20 to 70 MeV are providing a new means for studying nucleon-nucleon correlations in nuclei. At these energies the nucleus is relatively transparent, allowing simpler theoretical models to be used in interpreting the data and leading to a clearer picture. Also the contribution to DCX of sequential charge-exchange scattering through the intermediate analog state is suppressed near 50 MeV and transitions through non-analog intermediate states become very important. Recent theoretical studies by several groups have shown that while transitions through the analog route involve relatively long nucleon-nucleon distances, those through non-analog intermediate states obtain nearly half their strength from nucleon pairs with less than 1 fermi separation. Thus DCX near 50 MeV is an excellent way to study short-range nucleon-nucleon correlations. 31 refs., 29 figs., 4 tabs.
Date: January 1, 1989
Creator: Leitch, M.J.
Partner: UNT Libraries Government Documents Department

Search for primarily non-interacting decay modes of the upsilon

Description: The hadronic transition UPSILON(2S) ..-->.. ..pi../sup 0/..pi../sup 0/UPSILON(1S) is utilized to search for the reactions: UPSILON(1S) ..-->.. non-interacting particles and UPSILON(1S) ..-->.. ..gamma.. + non-interacting particles. 44 pb/sup -1/ of UPSILON(2S) data were taken by the Crystal Ball detector at the DORIS II storage ring in order to perform this study. An upper limit of BR(UPSILON ..-->.. Unseen) < 12% (90% C.L.), is obtained via this approach. The second process investigated involved the radiative decay of the Upsilon into non-interacting particles. 57 pb/sup -1/ of UPSILON(2S) data was available for this study. An upper limit on the branching ratio BR(UPSILON ..-->.. ..gamma.. + Unseen) is measured for photon energies in the range 500 MeV < E..gamma.. < M/sub ..gamma..//2. This is the first reported measurement of this type. For the highest energy photons, an upper limit of BR(UPSILON ..-->.. ..gamma.. + Unseen) < 2.3 x 10/sup -3/ (90% C.L.), is obtained. The compact size of the Crystal Ball detector enhances the observable branching ratio for noninteracting particles with short lifetimes such as massive axions. The identification of the recent Darmstadt events with a 1.6 MeV axion is excluded by the present result assuming the minimal Peccei-Quinn model. Limits on the spontaneous supersymmetry breaking mass scale are also derived as a function of gravitino mass.
Date: March 1, 1986
Creator: Leffler, J.S.
Partner: UNT Libraries Government Documents Department

Associated production of hypernuclei

Description: The characteristics of the (..pi../sup +/,k/sup +/) reaction, a new experimental tool to produce hypernuclei, are discussed. Results from a recent (..pi../sup +/,k/sup +/) experiment are presented. Some future prospects of the (..pi../sup +/,k/sup +/) reaction are discussed. 31 refs., 12 figs.
Date: January 1, 1985
Creator: Peng, J.C.
Partner: UNT Libraries Government Documents Department

Recent hypernuclear research at the Brookhaven AGS

Description: Recent AGS experiments contributing to our knowledge of hypernuclei are reviewed. These experiments have suggested new areas of research on hypernuclei. With the proper beam line facilities, the AGS will be able to perform experiments in these areas and provide a transition to the future era of ''kaon factories''. 20 refs., 14 figs.
Date: January 1, 1985
Creator: Chrien, R.E.
Partner: UNT Libraries Government Documents Department