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T864 (MiniMax): A search for disoriented chiral condensate at the Fermilab Collider

Description: A small test/experiment has been performed at the Fermilab Collider to measure charged particle and photon multiplicities in the forward direction, {eta} {approximately} 4.1. The primary goal is to search for disoriented chiral condensate (DCC). The experiment and analysis methods are described, and preliminary results of the DCC search are presented.
Date: October 1, 1996
Creator: Bjorken, J.D.
Partner: UNT Libraries Government Documents Department

The Exclusive Investigation of Multiple Production in Rapidity Space

Description: Recently it has become clear that only an inclusive model is not enough to explain interaction mechanism in the high energy region. We have been analyzing about the multiple meson production by using accelerator data and have gotten the conclusion that the exclusive investigation of rapidity gives an important information about the interaction mechanism. The experiment aims to measure the rapidity of the charged particles excluSively for individual event and to investigate the correlation among the number of charged particles Nc, the rapidity density {rho}, the mean value {bar {eta}} and the dispersion {sigma} of a rapidity distribution for each event.
Date: January 1, 1985
Creator: Nanjo, H.; Noto, Y.; Ishikawa, K. & U., /Hirosaki
Partner: UNT Libraries Government Documents Department

Studies of multiparticle production in hadronic Z{sup 0} decays

Description: Hadronic decays of Z{sup 0} bosons produced in e{sup +}e{sup {minus}} annihilation are ideal for testing QCD. This thesis presents a measurement of the charged-particle multiplicity distribution and the first experimental study of the ratio of cumulant to factorial moments, using hadronic Z{sup 0} decays collected by the SLD experiment at SLAC. The author finds that this ratio, as a function of the moment-rank q, decreases sharply to a negative minimum at q = 5, which is followed by quasi-oscillations. These features are in qualitative agreement with expectations from higher-order perturbative QCD. The author also presents an analysis of the intermittency in rapidity phase space using the method of scaled factorial moments. It is found that both parton cascade and hard-gluon radiations contribute to the growth of the moments by studying the event-shape and jet-topology dependencies. All aspects of the data appear to be reproduced reasonably well by the QCD-based Monte Carlo model.
Date: December 1, 1996
Creator: Zhou, Jingchen
Partner: UNT Libraries Government Documents Department

A search for disoriented chiral condensate at Fermilab

Description: A small test/experiment at the Fermilab Collider which measures charged particle and photon multiplicities in the forward direction, {eta} {approx} 4.1, has been carried out, with the primary goal being the search for disoriented chiral condensate (DCC). The author describes the experiment and analysis methods, together with preliminary results.
Date: October 1, 1996
Creator: Bjorken, J.D.
Partner: UNT Libraries Government Documents Department

Studies of topological distributions of the three- and four-jet events in {bar p}p collisions at {radical}s = 1800 GeV with the D0 detector

Description: The global topologies of three- and four-jet events produced in {bar p}p interactions are described. the three- and four-jet events are selected from data recorded by the D0 detector at the Tevatron Collider operating at a center-of-mass energy of {radical}s = 1800 GeV. the measured normalized distributions of various topological variables are compared with parton-level predictions of the tree- level QCD calculations. The parton-level QCD calculations are found to be in good agreement with the data. The studies also show that the topological distributions of the different subprocesses involving different numbers of quarks are very similar and reproduce the measured distributions well.
Date: July 1, 1995
Creator: Abachi, S.
Partner: UNT Libraries Government Documents Department

Study of the structure of the events produced in soft {bar p}p interactions at {radical}s = 1800 GeV

Description: In this note preliminary results on a systematic study of the event structure dependence on the event multiplicity and/or event average p{sub t} are presented. The mean p{sub t}, the short range pseudorapidity correlations and the mean sphericity are analysed as a function of the event multiplicity. The mean sphericity and the mean multiplicity are studied as a function of the event average p{sub t}.
Date: December 1, 1994
Creator: Rimondi, F.
Partner: UNT Libraries Government Documents Department

Antineutrino--proton interactions in the 15-foot bubble chamber

Description: From 24,000 pictures of the Fermilab 15-foot hydrogen bubble chamber exposed to a broad band anti $nu$ beam, there were 89 anti $nu$p $Yields$ $mu$$sup +$ + X$sup 0$ events with a total momentum in the charged tracks greater than 5 GeV/c obtained. The techniques used to identify the muon are discussed, and the anti $nu$ energy is estimated. The charged particle multiplicity distributions and the mean $pi$$sup 0$ multiplicity are presented. The semi- inclusive X, Y, Z, Q$sup 2$ and W distributions are compared with model predictions. The rate of strange particle production is measured. No evidence was found for charm particle production. (auth)
Date: January 1, 1975
Creator: Barish, S.J.; Derrick, M. & Dombeck, T.
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

A study of multi-jet production ratios in p{anti p} collisions at D0

Description: The authors study inclusive jet multiplicity ratios in multi-jet events from p{anti p} collisions at {radical}s = 1.8 TeV recorded using the D0 detector at the Fermilab Tevatron collider. Preliminary average multi-jet production ratios are presented as a function of the scalar jet transverse energy and compared to NLO calculations.
Date: September 1, 1996
Creator: Gallas, E.
Partner: UNT Libraries Government Documents Department

Particle production measurements by E802/E859/E866 and recent results from NMA in {sup 196}Au + {sup 196}Au collisions at 11.6 A{center_dot}GeV/c

Description: A summary of the particle production measurements in relativistic nucleus-nucleus collisions by the E802/E859/E866 Collaboration at the Brookhaven National Laboratory AGS-Tandem accelerator complex is presented. These results have been collected since 1986 through a series of experiments using the E802/E859/E866 spectrometer/calorimeter system. Also included are the latest results from the E866 collaboration using the New Multiplicity Array (NMA) detector for pion multiplicity measurements and for global event characterization of large entropy production in central Au + Au collisions. The detector consists of 346 lucite Cerenkov modulus surrounding the target, covering the pseudorapidity interval between {minus}0.4 and 2.8.
Date: December 31, 1995
Creator: Fung, Sun-yiu
Partner: UNT Libraries Government Documents Department

Short range rapidity correlations from the Bose-Einstein effect and intermittency: A quantitative demonstration

Description: A measurement of the two-particle correlation of identified pions was performed in the E802/E859 magnetic spectrometer on the interval 1.5 {le} y {le} 2.0, {delta}{phi} = 0.4 rad, for central {sup 28}Si + Au collisions. It is demonstrated that the two-pion correlation in rapidity is entirely due to Bose-Einstein interference. The directly measured exponential correlation length is {zeta}{sub y} = 0.20 {+-} 0.03 for two {pi}{sup {minus}}, with strength R(0,0) {approximately} 1%, in agreement with previous E802 indirect measurements derived from an analysis of intermittency using Negative Binomial Distributions.
Date: May 15, 1997
Creator: Tannenbaum, M.J. & Collaboration, E802 /E859
Partner: UNT Libraries Government Documents Department

Inclusive jet cross section in p{bar p} collisions with the D0 detector

Description: The authors report on two preliminary measurements of the central inclusive jet cross section at {radical}s = 1.8 TeV. The two data sets with integrated luminosities of 91 pb{sup {minus}1} and 14 pb{sup {minus}1} were collected at the Fermilab Tevatron p{bar p} Collider with the D0 detector. The cross section, reported as a function of transverse jet energy 35 GeV {le} E{sub {tau}} {le} 470 GeV and in the pseudorapidity interval {vert_bar}{eta}{vert_bar} {le} 0.5, is in excellent agreement with next-to-leading order QCD.
Date: July 1, 1996
Creator: Gomez, B.; Hoeneisen, B. & Negret, J.P.
Partner: UNT Libraries Government Documents Department


Description: Many domestic oil fields are facing abandonment even though they still contain two-thirds of their original oil. A significant number of these fields can yield additional oil using advanced oil recovery (AOR) technologies. To maintain domestic oil production at current levels, AOR technologies are needed that are affordable and can be implemented by independent oil producers of the future. Microbial enhanced oil recovery (MEOR) technologies have become established as cost-effective solutions for declining oil production. MEOR technologies are affordable for independent producers operating stripper wells and can be used to extend the life of marginal fields. The demonstrated versatility of microorganisms can be used to design advanced microbial systems to treat multiple production problems in complex, heterogeneous reservoirs. The proposed research presents the concept of a combined microbial surfactant-polymer system for advanced oil recovery. The surfactant-polymer system utilizes bacteria that are capable of both biosurfactant production and metabolically-controlled biopolymer production. This novel technology combines complementary mechanisms to extend the life of marginal fields and is applicable to a large number of domestic reservoirs. The research project described in this report is performed jointly by, Bio-Engineering Inc., a woman owned small business, Texas A&M University and Prairie View A&M University, a Historically Black College and University. This report describes the results of our laboratory work to grow microbial cultures and the work done on recovery experiments on core rocks. We have selected two bacterial strains capable of producing both surfactant and polymers. We have conducted laboratory experiments to determine under what conditions surfactants and polymers can be produced from one single strain. We have conduct recovery experiments to determine the performance of these strains under different conditions. Our results do not show a significant influence of nutrient regime on alternate production of surfactants or polymers.
Date: August 2004
Creator: Gabitto, Jorge & Barrufet, Maria
Partner: UNT Libraries Government Documents Department

A measurement of quark and gluon jet differences at the Z{sup 0} resonance

Description: The authors have studied differences between quark and gluon jets using 3-jet events in hadronic decays of Z{sup 0} bosons collected by the SLD experiment at SLAC. Gluon jets were identified in symmetric 3-jet events containing one jet tagged as a heavy quark jet and compared with a mixed sample of quark and gluon jets and also with a mixed sample of light quark (u, d and s) and gluon jets. Their preliminary results show that the particle multiplicity in gluon jets is higher than that in light quark jets. These results are in qualitative agreement with QCD expectations. Differences are also observed in particle energy spectra and the jet widths, consistent with QCD expectations.
Date: August 1, 1994
Creator: Iwasaki, Yoshihito
Partner: UNT Libraries Government Documents Department

Measurement of the charged multiplicity of Z{sup 0} {yields} b{bar b} events

Description: Using an impact parameter tag to select an enriched sample of Z{sup 0} {yields} b{bar b} events, the authors have measured the difference between the average charged multiplicity of Z{sup 0} {yields} b{bar b} and Z{sup 0} {yields} hadrons to be {bar n}{sub b} - {bar n}{sub had} = 2.24 {+-} 0.30(stat.) {+-} 0.33(syst.) tracks per event. From this, they have derived {bar n}{sub b} - {bar n}{sub uds} = 3.31 {+-} 0.41 {+-} 0.79. Comparing this measurement with those at lower center-of-mass energies, the authors find no evidence that {bar n}{sub b} - {bar n}{sub uds} depends on energy, in agreement with a precise prediction of perturbative QCD.
Date: August 1, 1994
Creator: Burrows, P. N.
Partner: UNT Libraries Government Documents Department

Neutral strange particle production in $pi$ tau interactions at 250 GeV/c

Description: Neutral strange particles were studied in about one third of a 46,000 picture exposure of 250-GeV/c pions in the Fermilab 15 foot bubble chamber. This chamber is particularly well suited for the study of neutral particles because of its large volume. Experimental inclusive cross sections are sigma (K/sub s/$sup 0$) equals 4.17 +- 0.45 mb, sigma (LAMBDA$sup 0$) = 1.74 +- 0.24 mb, sigma (anti LAMBDA$sup 0$) = 0.82 +- 0.13 mb. The average number of K/sub s/$sup 0$, LAMBDA$sup 0$, anti LAMBDA$sup 0$ per inelastic collision are approximately independent of charge multiplicity. F$sub 1$(x) and F$sub 2$(p/sup 2// sub t/) distributions as well as two strange particle mass plots are presented. (auth)
Date: January 1, 1975
Creator: Bogert, D.; Hanft, R. & Harris, R.
Partner: UNT Libraries Government Documents Department

Collective enhancement of inclusive cross sections at large transverse momentum in stochastic-field multiparticle theory

Description: A stochastic-field calculus, previously discussed in connection with Regge intercepts and instability questions, is applied to inclusive cross sections, and is shown to predict a growth with energy of large-P/perpendicular/ to inclusives. (auth)
Date: January 1, 1976
Creator: Arnold, R.C.
Partner: UNT Libraries Government Documents Department

Bevatron Operation and Development. V

Description: A considerable number of major improvements have been made in experimental facilities this quarter. These include four targets, three air locks, a deep well, and several thin windows for beam extraction in the target area. Simultaneous operation of up to five experiments has been achieved with a relay-controlled automatic operations selector. A beam-amplitude regulating device has been used to set the beam level on any pulse to within a few percent. The range of this equipment is 1000:1. Experimentation on the accelerator this quarter included measurements of start frequency and frequency-tracking jitter, beam-versus-radial-aperture measurements, empirical study of gas scattering effects, and preliminary testing of an automatic beam-controlled frequency-tracking system. High-energy physics experiments have been performed by ten groups within this laboratory. These groups are using counter techniques for the elastic proton-proton scattering, K-particle half-life determination, and {pi}{sup -}-meson cross-section measurements. A high-pressure hydrogen diffusion chamber is being used to study multiple production of {pi}{sup -} mesons. A strong-focusing pair spectrometer has been used to produce beams of K particles. Emulsion exposures have been made to determine the masses and mean lifetimes of K mesons. The interactions and modes of decay of K{sup {+-}} mesons at rest, as well as in flight, have been studied in emulsions.
Date: August 24, 1955
Creator: Lofgren, Edward J. & Heard, Harry G.
Partner: UNT Libraries Government Documents Department