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K-matrix fits to $pi$N $Yields$ N$pi$ and N$pi$$pi$ in the resonance region $Root$s = 1.3 to 2.0 GeV

Description: Thesis. Starting with partial wave amplitudes for pi N yields N pi and pi N yields several isobar model states of N pi pi , one can apply the constraint of unitarity (using the K-matrix). This permits the removal of the overall phase ambiguity of the isobar amplitudes at each energy. The K-matrix fits generated a smooth prescription for the T-matrix amplitudes, enabling one to search the complex energy plane for poles. The uniqueness of these poles was demonstrated by doing Breit-Wigner refits to the fitted T-matrix amplitudes. The success of the results and the obvious interpretation justified a simple determination of coupling signs for which there can be checks with theory. This thesis corresponds closely to a forthcoming paper submitted to Physical Review except that here the K-matrix is based on a 1972 solution A'' isobar-model fits to N pi pi data, and in the final paper solution B'' is used. (auth)
Date: October 1, 1973
Creator: Longacre, R.S.
Partner: UNT Libraries Government Documents Department

Future opportunities for hadron spectroscopy at the MPS

Description: Before I go into detailed MPS experiments, I will give a summary of the status of lattice gauge calculations of glueball masses plus glueball and hybrid masses from the bag model, and the flux tube model. For the following discussion, I am going to assume that multi-quark states or molecules are best described in terms of the MIT bag model of Jaffe with its spectrum best defined by work done by R.L. Jaffe and F.E. Low using a method called The P-Matrix. Using this method one sees that all 4-quark states will appear as very broad continuum like effects that one would not associate with meson resonances, except for the S* and the delta which forms a very special threshold K/bar K/ bound systems. There is a possibility that the E(1420) may also be related to the J/sup PC/ = 1/sup + +/, qq/bar q//bar q/ spectrum having its width narrowed by a final state interaction.
Date: December 7, 1988
Creator: Longacre, R.S.
Partner: UNT Libraries Government Documents Department

Multiparticle magnetic spectrometer with dE/dx and TRD particle identification

Description: Recent advances in detector development by BNL, CCNY and other groups have made possible new designs of fast high resolution large effective solid angle magnetic multiparticle spectrometers with excellent particle tracking, momentum measurement, and identification capability. These new spectrometers are relatively compact and relatively low cost electronics have been developed for them. Thus the cost is relatively low. These techniques are applied here primarily for design of spectrometers for low p/sub t/ and other physics (at moderate and even high p/sub t/) in the ISABELLE small angle hall. However, one should keep in mind that these techniques can be utilized in many other applications.
Date: January 1, 1981
Creator: Lindenbaum, S.J. & Longacre, R.S.
Partner: UNT Libraries Government Documents Department

Glueball resonance and alternative explanations of the reaction. pi. /sup -/p. -->. phi phi n*

Description: The observation of three resonances (in the reaction ..pi../sup -/p ..-->.. phi phi n) which break down the OZI suppression was attributed to the production of these states by 1-3 glueball(s). The final partial wave analysis of approx. = 4000 phi phi n events was presented and agrees with prior publications within errors. Alternative explanations in terms of otherwise explaining the OZI suppression breakdown or finding other kinematic mechanisms to explain the BNL/CCNY data are discussed and found to be incorrect and do not fit the characteristics of the experimental data. 18 refs., 6 figs.
Date: January 1, 1985
Creator: Lindenbaum, S.J. & Longacre, R.S.
Partner: UNT Libraries Government Documents Department

Techniques in meson spectroscopy

Description: This report contains lectures on the following topics: the quark model and beyond using quantum chromodynamics; analysis of formation reactions; energy dependence of the partial wave amplitudes; where the data for the t-matrix analysis comes from; and coupled channel analysis of isoscalar mesons.
Date: December 31, 1991
Creator: Longacre, R. S.
Partner: UNT Libraries Government Documents Department

HIJET with AGS physics and N{sup *}`s

Description: We investigate the effects of secondary interactions in nucleus- nucleus and proton-nucleus collisions using a modified HIJET Monte Carlo generator. The effects of N{sup *} production is explored and it is found that the numbers of kaons can almost be explained by their inclusion. However the transverse momentum spectrum of the kaons is not explained, since their production in HIJET is a soft secondary scattering process and not a hot thermal process like the data.
Date: February 11, 1993
Creator: Longacre, R. S.
Partner: UNT Libraries Government Documents Department

The q q meson states with J sup PC = 2 sup ++ and 0 sup ++

Description: The lowest mesons made up of a light quark and a strange quark produced from a K beam show a good agreement with expectations of the quark model. This good agreement leads to the prediction of the light isoscalar and isovector states and the isoscalar s{bar s} states. Except for one mystery The X(1590) the 2{sup ++} states seems to be well described by the expected ideally mixed q{bar q} states up to 2. 0 GeV. Above 2.0 GeV a new degree of freedom seems to be excited with respect to the breakdown of the OZI rule in production of 2{sup ++} resonances that decay into {phi}{phi}. This is to be contrasted with the situation for the O{sup ++} isoscalar states which seems to show a new degree of freedom for its mesons in its ground state. One might conclude that since the O{sup ++} glueball is predicted by lattice calculations to be degenerate with the s{bar s} O{sup ++} meson, that the very unusual assortment of isoscalar O{sup ++} mesons are due to glueball mixing.
Date: September 26, 1991
Creator: Longacre, R.S.
Partner: UNT Libraries Government Documents Department

HIJET with AGS physics and N[sup *]'s

Description: We investigate the effects of secondary interactions in nucleus- nucleus and proton-nucleus collisions using a modified HIJET Monte Carlo generator. The effects of N[sup *] production is explored and it is found that the numbers of kaons can almost be explained by their inclusion. However the transverse momentum spectrum of the kaons is not explained, since their production in HIJET is a soft secondary scattering process and not a hot thermal process like the data.
Date: February 11, 1993
Creator: Longacre, R.S.
Partner: UNT Libraries Government Documents Department

MASS SHIFTS THROUGH RE - SCATTERING.

Description: In this report the authors present a model that can produce a mass shift in a resonance due to interference between a scattering amplitude and that amplitude having rescattering through the resonance.
Date: March 31, 2003
Creator: LONGACRE,R.S.
Partner: UNT Libraries Government Documents Department

Parton structure through two particle correlations in Au-Au at RHIC

Description: A method for determining the presence of partonic scattering through two-particle correlations is developed and applied to models which have jets and mini-jets in them. The author only considers the correlation of mid-rapidity particles because they will be easily measured in large numbers at RHIC. The level of two-particle correlations will be a direct measure of how dense a system is made in Au-Au collisions at RHIC. The STAR TPC will be ideal for making these measurements in the first year of running.
Date: December 31, 1998
Creator: Longacre, R.S.
Partner: UNT Libraries Government Documents Department

The {pi}{sub 1}(1400) meson as a K{anti K}{pi}{pi} molecule

Description: In this paper the {pi}{sub 1}(1400) meson with J{sup PC} = 1{sup {minus}+} is speculated to be a molecule state which has a similar binding mechanism as the f{sub 1}(1420). With analogy to the f{sub 1}(1420) as a pion orbiting in a P-wave around an S-wave K{anti K} system, the authors have a pion orbiting in a P-wave around an S-wave K{anti K}{pi} system resonating in the {eta}(1295). In order to completely derive the dynamics one would have to develop a true four-body scattering mechanism with Born terms connecting two- and three-body isobar states ({eta}(1295), {rho}(770), a{sub 0}(98), K{sub 1}(1270)). Here they take a short cut and assume a simpler three-body Born term analogous to the final state rescattering mechanism that generated the f{sub 1}(1420). The interactions of the a{sub 0}(980) with the {rho}(770) through a kaon exchange, which would require a four-body treatment, are replaced by a modification of the P-wave {pi}{pi} phase shift. If they allow this modification then binding like the F{sub 1}(1420) can occur. Furthermore when the {eta}(1295) is formed in rescattering at momentum outside the K{anti K} {pi}{pi} phase space, they assume the {eta}(1295) will couple to the ground state {eta} since its quarks and quantum numbers are the same, thus creating {eta}{pi} in a P-wave decay.
Date: December 1, 1997
Creator: Longacre, R.S.
Partner: UNT Libraries Government Documents Department

H{sub 0} candidates from the decays {Sigma}{sup {minus}}p and {Lambda}p{pi}{sup {minus}}, produced in heavy ion collisions Si beam on Pb target

Description: There is considerable interest in searching for strange quark matter (strangelets). The lowest strangelet state is thought to be a six quark dibaryon singlet spin zero state called the H{sub 0} predicted by R.L. Jaffe. The authors present H{sub 0} candidate events, where H{sub 0}(2210) is observed through the weak decay modes {Sigma}{sup {minus}}p and {Lambda}p{pi}{sup {minus}}, produced in central heavy ion collisions with 14.6 x A Gev/c Si beam on Pb target. The lifetime is consistent with {approximately}4 cm cr in both channels approximately 1/3 of an H{sub 0}(2210) which decays into {Sigma}{sup {minus}} p is produced per central Si Pb collision. The branching ratio between {Lambda}p{pi}{sup {minus}} and {Sigma}{sup {minus}}p is around 11% {+-} 3%.
Date: December 1, 1997
Creator: Longacre, R.S.
Partner: UNT Libraries Government Documents Department

PARTON STRUCTURE THROUGH TWO PARTICLE CORRELATIONS IN AU-AU AT RHIC.

Description: A method for determining the presence of partonic scattering through two-particle correlations is developed and applied to models which have jets and mini-jets in them. We only consider the correlation of mid-rapidity particles because they will be easily measured in large numbers at RHIC. The level of two-particle correlations will be a direct measure of how dense a system is made in Au-Au collisions at RHIC. The STAR TPC will be ideal for making these measurements in the first year of running.
Date: October 23, 1999
Creator: LONGACRE,R.S.
Partner: UNT Libraries Government Documents Department

Operation of the Brookhaven MPS II Facility

Description: The BNL Multiparticle Spectrometer has recently been equipped with a set of narrow cell drift chambers employing a novel, compact, inexpensive, readout scheme. This has given an order of magnitude improvement in beam rate as well as better spatial resolution. Two experiments have been completed in the first year of operation, a good test of the system. This type of a drift chamber arrangement is ideal for use at high luminosity hadron colliders.
Date: January 1, 1983
Creator: Etkin, A.; Foley, K.J. & Longacre, R.S.
Partner: UNT Libraries Government Documents Department

A Comparison between a Minijet Model and a Glasma Flux Tube Model for Central Au-Au Collisions at sqrt NN=200 GeV

Description: In this paper we compare two models with central Au-Au collisions at sqrtsNN=200 GeV. The first model is a minijet model which assumes that around ~50 minijets are produced in back-to-back pairs and have an altered fragmentation functions. It is also assumed that the fragments are transparent and escape the collision zone and are detected. The second model is a glasma flux tube model which leads to flux tubes on the surface of a radial expanding fireball driven by interacting flux tubes near the center of the fireball through plasma instabilities. This internal fireball becomes an opaque hydro fluid which pushes the surface flux tubes outward. Around ~12 surfaceflux tubes remain and fragment with ~1/2 the produced particles escaping the collision zone and are detected. Both models can reproduce two particle angular correlations in the different pt1 pt2 bins. We also compare the two models for three additional effects: meson baryon ratios; the long range nearside correlation called the ridge; and the so-called mach cone effect when applied to three particle angular correlations.
Date: May 17, 2011
Creator: Longacre, R.S.
Partner: UNT Libraries Government Documents Department

Bumps and poles in the S-matrix: A systematic study of 0 sup ++ and 2 sup ++ mesons plus a molecule approach to the E(1420) in the K K. pi. system

Description: The goal of Hadron Spectroscopy is to find the spectrum of states formed by color singlet arrangements of quarks and gluons. Ideally these spectral states are associated with poles of the scattering matrix of hadrons which are the decay channels of the states. For example the {rho} meson is the lowest q{bar q} s-wave, spin one color singlet state and decays into {pi}{sup +}{pi}{sup -}. Since the {rho}decays in a relative p-wave, one finds the {rho} pole in the I = 1 p-wave {pi}{pi} phase shifts. There are forces between quarks and gluons which do not manifest themselves as true resonances and thus cannot be described by a Breit-Wigner pole. I will give some examples that are not Breit-Wigner poles of the scattering matrix but are important bumps in meson production. 22 refs., 10 figs.
Date: November 16, 1989
Creator: Longacre, R.S.
Partner: UNT Libraries Government Documents Department

Glueballs in the reaction. pi. /sup -/p. -->. phi phi n

Description: The BNL/CCNY collaboration has increased the statistics on the reaction 22 GeV/c ..pi../sup -/p ..-->.. phi phi n from 1203 to approx. = 4000 events. A preliminary partial wave analysis yields three states, all with J/sup PC/ = 2+/sup +/, which we conclude are produced by glueballs. Previously we had two such states, both with J/sup PC/ = 2/sup + +/. The data analysis, and the QCD arguments for these states being produced by glueballs will be presented and discussed.
Date: January 1, 1983
Creator: Etkin, A.; Foley, K.J. & Longacre, R.S.
Partner: UNT Libraries Government Documents Department

Characteristics of the new MPS II spectrometer system

Description: The BNL MPS II is a conversion of the spark chamber detector system of MPS I to a narrow drift space novel drift chamber system. A description is given of this very compact drift chamber system in which the electronics for individual channels is mounted on the chamber. Under actual experimental operating conditions, the chamber shows high resolution of approx. = 200 microns, are dead-time free, and yielded excellent performance. The digital electronics used eliminates channel-by-channel corrections. We have used it in a very large drift chamber system for which it is well suited since it requires less than one integrated circuit per channel. A description of the system, its testing, its use and results obtained in an experiment is presented and discussed.
Date: January 1, 1982
Creator: Etkin, A.; Foley, K.J. & Longacre, R.S.
Partner: UNT Libraries Government Documents Department

Secondary interactions in HIJET

Description: This talk deals with the investigation of secondary interactions in proton-nucleus and nucleus-nucleus collisions using the Monte Carlo event generator HIJET.
Date: April 2, 1990
Creator: Longacre, R.S.
Partner: UNT Libraries Government Documents Department

CAN RECENT CHARGE FLUCTUATION CALCULATIONS BE A RELIABLE SIGNAL FOR A QGP AT RHIC?

Description: The recent papers of Jeon and Koch[l] and Asakawa, Heinz and Muller[2] propose that the event by event fluctuations of the ratio of the positively charged and negatively charged pions could provide a distinct signal for a QGP at RHIC/LHC due to differences in those from the QGP phase, and the Hadron Gas Phase. In this paper we point out that aside from the questionability of the many assumptions in the treatment used, even following their approach there are other effects not considered, e.g. color charge fluctuations which we show could significantly or completely wash out the proposed signal. Therefore lack of observation of these charge fluctuation signals cannot lead one to conclude that a QGP is not formed at RHIC. A general discussion of experimental requirements for observation of such signals (if they exist) and how to interpret them is included.
Date: August 1, 2001
Creator: LINDENBAUM, S.J. & LONGACRE, R.S.
Partner: UNT Libraries Government Documents Department

SEARCHING FOR QUARK - GLUON PLASMA (QGP) BUBBLE EFFECTS AT RHIC / LHC.

Description: Since the early eighties, we have shared with Leon Van Hove the view that if a QGP were produced in high energy heavy ion colliders that its hadronization products would likely come from small localized in phase space bubbles of plasma. In previous papers we have discussed the case where one to at most a few separated bubbles were produced. In this paper we develop a model based on HIJING to which we added a ring of adjoining multi bubble production, which we believe is a higher cross-section process which dominates the near central rapidity region. We have performed simulations which were designed to be tested by the expected first to become available suitable test data, namely the forthcoming RHIC STAR detector data on 65Gev/n Au colliding with 65 Gev/n Au. We took into account background effects and resonance effects so that a direct comparison with the data, and detailed test of these ideas could be made in the near future. Subsequently 100 Gev/n Au on 100 Gev/n Au forthcoming data can be tested, and of course these techniques, suitably modified by experience can be applied to it and eventually to LHC. We concluded that two charged particle correlations versus the azimuthal angle {Delta}{phi}; vs the opening angle, and vs psuedorapidity {eta}, can detect important bubble signals in the expected background, with statistical significances of 5 - 20{sigma}, provided the reasonably conservative assumptions we have made for bubble production occur. We also predicted charge fluctuation suppressions which increase with the bubble signal, and range from {approx} 5% to 27% in the simulations performed. We demonstrated reasonably that in our model, these charge suppression effects would not significantly be affected by resonances.
Date: March 1, 2003
Creator: LINDENBAUM,S.J.; LONGACRE,R.S. & KRAMER,M.
Partner: UNT Libraries Government Documents Department

PARTON BUBBLE MODEL FOR TWO PARTICLE ANGULAR CORRELATIONS AT RHIC/LHC.

Description: In an earlier paper we developed a bubble model, based on a view we had shared with van Hove for over two decades. Namely, that if a quark-gluon plasma is produced in a high energy heavy ion collider, then its hadronization products would likely be emitted from small bubbles localized in phase space containing plasma. In this paper we refined the model to become a parton bubble model in which each localized bubble contains initially 3-4 partons which are almost entirely gluons forming a gluon hot spot. We greatly expanded the transverse momentum interval investigated, and thus are able to treat recombination effects within each bubble. We again utilize two particle correlations as a sensitive method for detecting the average bubble substructure. In this manuscript we make many predictions for angular correlations detectable at RHIC and which will be later modified to LHC conditions. Some early available low precision correlation analyses is qualitatively explained. However a critical consistency test of the model can be made with high precision data expected in the near future.
Date: June 27, 2006
Creator: S.J., LINDENBAUM & LONGACRE, R.S.
Partner: UNT Libraries Government Documents Department