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Description: The energies of p-shell hypernuclear {gamma} rays obtained from recent experiments using the Hyperball at BNL and KEK are used to constrain the YN interaction which enters into shell-model calculations which include both {Lambda} and {Sigma} configurations.
Date: October 14, 2003
Creator: MILLENER,D. J.
Partner: UNT Libraries Government Documents Department

Final technical report, Outstanding Junior Investigator Award for DE-FG02-94ER40869

Description: This report summarizes the research of the Principal Investigator, his postdoctoral research associates, and his students during the period of the award. The majority of the work concerns the behavior of hadrons containing strange, charm, bottom and top quarks, with a particular focus on the extraction of Cabibbo--Kobayashi--Maskawa matrix elements from experiments performed on such systems.
Date: May 16, 2002
Creator: Falk, Adam F.
Partner: UNT Libraries Government Documents Department

Strange sea and alpha {sub s} measurements from nu - N deep inelastic scattering at CCFR/NuTeV

Description: We present the latest Next-to-Next-Leading order strong coupling constant, {alpha}{sub s}, extracted from Gross-Llewellyn-Smith sum rule. The value of {alpha}{sub s} from this measurement, at the mass of Z boson, is {alpha}{sub s}{sup NNLO} (M{sup 2}{sub Z}) = 0.114{sup +0.009}{sub -0.012}. We discuss the previous strange sea quark measurement from the CCFR experiment and the prospects for improvements of the measurement in the NuTeV experiment.
Date: August 1, 1998
Creator: Yu, J. & Collaboration, CCFR /NuTeV
Partner: UNT Libraries Government Documents Department

Strangeness production in relativistic nuclear collisions

Description: A review of strange particle production in heavy ion collisions from AGS to SPS energies is presented. Implications of the newest developments in understanding the collision dynamics and the role of strange particle production in the search for a new phase of matter, in both experimental and theoretical sectors, are discussed.
Date: January 1, 1998
Creator: Odyniec, G.J.
Partner: UNT Libraries Government Documents Department

Recent results from E885 -- A search for doubly strange objects

Description: E885, an experiment performed at the Brookhaven National Laboratory Alternate Gradient Synchrotron (BNL AGS) achieved high sensitivity in a search for {Lambda}{Lambda} hypernuclei, {Xi} hypernuclei, and the H particle. Evidence was found for {Xi} hypernuclei. Possible extensions of the methods used are discussed.
Date: October 23, 2000
Partner: UNT Libraries Government Documents Department

Stability of strange quark stars with nuclear crusts against radial oscillations

Description: This paper investigates the stability of the complete sequence of strange-matter stars with nuclear crusts against radial pulsations (acoustical modes). It is found that a broad class of white dwarf- like strange stars is stable against such pulsations. The same holds for the much denser strange stars, which are the strange counter-parts of neutron stars. All stars possessing still higher central densities (e.g., charm stars) turn out to be unstable.
Date: December 5, 1994
Creator: Kettner, Ch.; Weigel, M.K.; Weber, F. & Glendenning, N.K.
Partner: UNT Libraries Government Documents Department

Aspects of strangeness

Description: We review various aspects of strangeness production in relativistic heavy ion collisions from AGS to CERN energies. The experimental data are briefly summarized and various possible theoretical interpretations of these data are evaluated, such as quark-gluon- plasma (QGP), hadron gas (HG) thermal models, or event generators (cascade models). Some comments on the production of strange clusters are offered.
Date: March 1, 1995
Creator: Dover, C.B.
Partner: UNT Libraries Government Documents Department


Description: Experiment E906 at the BNL-AGS, searching for light S = -2 hypernuclei, found strong evidence for the nuclide {sub {Lambda}{Lambda}}{sup 4}H. Perhaps the most striking feature of this experiment was the presence in the data of a narrow low-momentum {pi}{sup -} line at k{sub {pi}} = 104-105 MeV/c. This line was ascribed to the decay of {sub {Lambda}{Lambda}}{sup 4}H into a resonant state in {sub {Lambda}}{sup 4}H. The existence of such a state is shown to be plausible, its characteristics delineated, and its relevance to ongoing theoretical calculations considered.
Date: October 14, 2003
Partner: UNT Libraries Government Documents Department

Strangeness at SIS energies

Description: In this contribution the authors discuss the physics of strange hadrons in low energy ({approx_equal} 1-2 AGeV) heavy ion collision. In this energy range the relevant strange particle are the kaons and anti-kaons. The most interesting aspect concerning these particles are so called in-medium modifications. They will attempt to review the current status of understanding of these in medium modifications. In addition they briefly discuss other issues related with kaon production, such as the nuclear equation of state and chemical equilibrium.
Date: September 28, 2005
Creator: Koch, Volker
Partner: UNT Libraries Government Documents Department

Strange particle production and s-quark asymmetry

Description: Using hadronic Z{sup 0} decays recorded by the SLD experiment at SLAC, we have studied the production of strange particles as a function of momentum. A high-purity sample of K{sup {+-}} was tagged using Cherenkov Ring Imaging Detector (CRID). The {phi}, {Lambda} and K{sub s} were reconstructed in the K{sup +}K{sup -}, p-{pi} and {pi}{sup +}{pi}{sup -} modes respectively, and CRID identification of K{sup {+-}} and p was used to obtain pure samples of {phi} and {Lambda}. We have used the high electron-beam polarisation delivered by the SLC to measure the left-right forward-backward production asymmetries of these particles, and discuss the relationship of these quantities to the underlying strange quark asymmetry in Z{sup 0} decays.
Date: August 1, 1996
Creator: Narita, S.
Partner: UNT Libraries Government Documents Department

Recent status in the search for the quark-gluon plasma

Description: The author reviews recent experimental results in the search for the quark-gluon plasma. Because the magnitudes of many signals for the plasma are directly proportional to the reaction cross sections, the author examines the corrections to the commonly used lowest-order cross sections. The author finds that the corrections are often significant and should be properly taken into account. The use of dileptons and photons with large transverse momenta is suggested as a means to study the boundary of the quark-gluon plasma.
Date: February 1, 1995
Creator: Wong, Cheuk-Yin
Partner: UNT Libraries Government Documents Department

Chiral Symmetries in Nuclear Physics

Description: The theoretical concepts of a chirally symmetric meson field theory are reviewed and an overview of the most relevant applications in nuclear physics is given. This includes a unified description of the vacuum properties of hadrons, finite nuclei and hot, dense and strange nuclear matter in an extended chiral SU(3){sub L}/SU(3){sub R} {sigma}-{omega} model.
Date: June 12, 2000
Creator: Zschiesche, D.; Papazoglou, P.; Schramm, S.; Beckmann, C.; Schaffner-Bielich, J.; Stocker, H. et al.
Partner: UNT Libraries Government Documents Department

Spin-orbit inversion of excited heavy quark mesons

Description: The mesonic heavy quark spin multiplets with s{sub l}{sup {pi}{sub l}}=(1/2){sup +} and (3/2){sup +} are expected to be the lowest-lying excitations about the pseudoscalar and vector ground states with s{sub l}{sup {pi}{sub l}}=(1/2){sup {minus}}. The author shows that for charm and bottom these multiplets are probably inverted, with the 2{sup +} and 1{sup +} states with s{sub l}{sup {pi}{sup l}}=(3/2){sup +} about 150 MeV below the 1{sup +} and 0{sup +} states with s{sub l}{sup {pi}{sub l}}=(1/2){sup +}. If verified, such an inversion would both support the expectation that confinement has no dynamical spin-dependence and indicate that heavy and light quark systems may be characterized by the same effective low-energy degrees of freedom. As an important byproduct, this work establishes the dynamics of the strange quark as a critical link between heavy- and light-quark hadrons, justifying efforts toward a much more complete experimental and theoretical understanding of strange mesons and baryons and of strangeonia.
Date: June 1, 1997
Creator: Isgur, Nathan
Partner: UNT Libraries Government Documents Department

Search for the H-dibaryon. A proposal to E871

Description: This report consists of vugraphs for a lecture on the search for the H-dibaryon. The physics importance of this search are: (1) low energy test of QCD; (2) new form of matter; (3) missing link between normal hadronic matter and strange matter; (4) astrophysical explanations; and (5) cosmology and dark matter. The author reviews past experiments searching for H-dibaryon. Finally he discusses search methods at E871.
Date: October 1, 1998
Creator: Fitch, V.; Klein, J. & May, M.
Partner: UNT Libraries Government Documents Department

Strange particle production in hadronic Z{sup 0} decays

Description: A study has been made of neutral strange baryons and pseudoscalar mesons produced in hadronic decays of the weak gauge boson V. The experiment was performed at the Stanford Linear Accelerator Center, which has the unique capability of colliding highly polarized electrons with unpolarized positrons. Overall production rates and spectra of the K{sup 0} and the {Lambda}{sup 0} (+{Lambda}{sup 0}) were measured and compared with other experiments as well as with Quantum Chromodynamics calculations. The combination of the small, stable beam spots produced by the SLAC Linear Collider (SLC) and the precision vertexing capabilities of the SLC Large Detector (SLD) permitted the separation of the hadronic events into three quark flavor-enriched samples. An unfolding was performed to obtain flavor-pure samples, and for the first time measurements were made of K{sup 0} and {Lambda}{sup 0} (+{Lambda}{sup 0}) production rates and spectra in uds, c, and b quark events at the Z{sup 0} pole. This measurement revealed significant production differences. Utilizing the large quark production asymmetry due to the polarized electron beam, high-purity quark and antiquark jet samples were obtained. The first measurement of production differences of the {Lambda}{sup 0} baryon in quark and antiquark jets was performed, which provided clear evidence for a leading particle effect at high momenta.
Date: April 1, 1996
Creator: Baird, K.G. III
Partner: UNT Libraries Government Documents Department

Strange Dibaryons

Description: Strange Dibaryons, six valence-quark hadrons constructed from one or more strange quarks, are predicted to have greater binding than dibaryons in the non-strange sector. The flavor-singlet dibaryon with quark structure ``uuddss`` is of particular theoretical and experimental interest. A brief review of the status of H dibaryon studies is presented with emphasis on experiment E813 currently taking data at the AGS.
Date: November 1, 1993
Creator: Franklin, G. B.; Athanas, M. & Barnes, P. D.
Partner: UNT Libraries Government Documents Department

Selected problems in experimental intermediate energy physics. Final technical report, February 1, 1991--January 31, 1994

Description: A complete description of the research program of the intermediate energy group at the University of Houston may be found in previous progress reports, renewal proposals, and proposals to various accelerator advisory committees. The summaries of activities are presented in the next section. The objectives of the research program are to: (1) investigate selected, forefront problems in experimental intermediate energy physics; (2) educate students in this field of research; and (3) develop the instrumentation necessary to undertake this experimental program. There were three major thrusts of the program: (1) strange particle physics, where a strange quark is embedded in the nuclear medium; (2) muon electro-weak decay, which involves a search for a violation of the standard model of the electro-weak interaction; and (3) measurement of the spin dependent structure function of the neutron and proton.
Date: October 1, 1997
Creator: Mayes, B.W.; Hungerford, E.V. & Pinsky, L.S.
Partner: UNT Libraries Government Documents Department

Strange particle measurements from the EOS TPC

Description: A high statistics sample of {Lambda}`s produced in 2 GeV/nucleon {sup 5}8Ni + {sup nat}Cu collisions has been obtained with the EOS Time Projection Chamber at the Bevalac. The coverage of the EOS TPC is essentially 100% for y > y{sub cm} and extends down to P{sub T} = 0 where interesting effects such as collective radial expansion may be important. In addition, the detection of a majority of the charged particles in the TPC, along with the presence of directed flow for protons and heavier fragments at this beam energy, allows for the correlation of A production with respect to the event reaction plane. Our preliminary analysis indicates the first observation of a sidewards flow signature for A`s. Comparisons with the cascade code ARC are made.
Date: February 1, 1995
Creator: Justice, M.
Partner: UNT Libraries Government Documents Department

Development of silicon drift detectors for strangeness measurements

Description: Detection of multi-strange and charm particles requires precise measurements of the secondary vertices close to the interaction point and the decay products of strange and charm particles. This presents an unprecedented challenge for relativistic heavy ion experiments, where multiplicity reaches thousands of final state particles per collision. Development of affordable technology for realizing high spatial resolution and low mass vertex detectors has become the ultimate goal of many R&D projects in major laboratories. In this paper we present preliminary results on silicon drift detectors fabricated for the first time on p-type silicon substrates. These detectors were designed, fabricated and tested recently at LBL and show very interesting properties which make their use in future experiments very likely.
Date: February 1, 1995
Creator: Odyniec, G.; Krieger, B.; Krofcheck, D.; Lewak, D.; O`Donnel, R.; Partlan, M. et al.
Partner: UNT Libraries Government Documents Department

Departure from the hadronic scenario at CERN SPS

Description: A review of results from heavy ion experiments at CERN SPS is presented, with an emphasis on the data from Pb induced interactions. Special focus is put on the most significant surprises: anomalous J/{Psi} suppression, change in the spectral shapes of e{sup +}e{sup {minus}} mass distributions in the vector meson domain, and enhanced strange hadron production. Implications of these findings for understanding collision dynamics and, in particular, their role in the search for the new phase of matter, are discussed.
Date: January 1, 1998
Creator: Odyniec, G.
Partner: UNT Libraries Government Documents Department

From nuclei to hypernuclei: A retrospective view of medium energy physics at Brookhaven

Description: A new frontier in physics originated with programs at two Brookhaven National Laboratory facilities--the Cosmotron and the Alternating Gradient Synchrotron. The development of this frontier over a half century is described, as it turned from conventional nuclear physics to the hypernuclei and the study of strange matter.
Date: October 23, 2000
Creator: Chrien, R.E.
Partner: UNT Libraries Government Documents Department