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Recent results from Fermilab E687 on charm spectroscopy

Description: Recent analyses of charm spectroscopy from Fermilab fixed target experiment 687 are summarized. Emphasis is placed on the phenomenology of Cabibbo suppression in the meson sector. Such transitions have been observed in the semileptonic modes and hadronic modes. While the former transitions give us an opportunity to observe the weak current and the CKM matrix, a systematic comparison of the latter transitions allow us to study strong interaction effects, and possibly, light quark spectroscopy.
Date: July 1, 1997
Creator: Lebrun, P.
Partner: UNT Libraries Government Documents Department

Neutral Kaon Interferometry in Au+Au collisions at sqrt(s_NN) =200 GeV

Description: We present the first statistically meaningful results fromtwo-K0s interferometry in heavy-ion collisions. A model that takes theeffect of the strong interaction into account has been used to fit themeasured correlation function. The effects of single and coupled channelwere explored. At the mean transverse mass m_T = 1.07 GeV, we obtain thevalues R = 4.09 +- 0.46 (stat.) +- 0.31 (sys) fm and lambda = 0.92 +-0.23 (stat) +- 0.13 (sys), where R and lambda are the invariant radiusand chaoticity parameters respectively. The results are qualitativelyconsistent with m_T systematics established with pions in a scenariocharacterized by a strong collective flow.
Date: August 5, 2006
Creator: Abelev, B.I.; Adams, J.; Aggarwal, M.M.; Ahammed, Z.; Amonett,J.; Anderson, B.D. et al.
Partner: UNT Libraries Government Documents Department

Prospects for the Precision Measurement of {alpha}{sub s}

Description: The prospects for the measurement of the strong coupling constant {alpha}{sub MS}(M{sub Z}) to a relative uncertainty of 1 % are discussed. Particular emphasis is placed on the implications relating to future High Energy Physics facilities.
Date: December 1996
Creator: Burrows, P. N.; Dixon, L. & El-Khadra, A. X.
Partner: UNT Libraries Government Documents Department

Evaluation of Simplified Methods for Estimating Shear Capacity Using JNES/NUPEC Low-Rise Concrete Shear Wall Cyclic Test Data.

Description: The simplified methods in current codes for determining the shear capacity of reinforced concrete shear walls had mostly been validated using the test results of single-element shear walls. Recently available JNES/NUPEC test data of reinforced concrete shear walls under multi-directional cyclic loadings provided a unique opportunity to investigate the adequacy of the simplified methods for use in situations with strong interaction effects. A total of 11 test specimens with aspect ratios between 0.47 and 0.87 have been used in the assessment. Two simplified methods from the ACI 349-01 standard [1] and one from the ASCE 43-05 standard [2] have been evaluated. This paper also presents the development of an adjustment factor to consider the aspect ratio and the development of two approaches to consider interaction effects for one of the simplified methods. It concludes with the insights on the applicability of the code methods when interaction effects exist.
Date: June 1, 2008
Creator: Nie,J.; Braverman, J.; Hofmayer, C. & Ali, S.
Partner: UNT Libraries Government Documents Department

An Approach for Assessing Structural Uplifting Using Blast Motions.

Description: The simplified methods in current codes for determining the shear capacity of reinforced concrete shear walls had mostly been validated using the test results of single-element shear walls. Recently available JNES/NUPEC test data of reinforced concrete shear walls under multi-directional cyclic loadings provided a unique opportunity to investigate the adequacy of the simplified methods for use in situations with strong interaction effects. A total of 11 test specimens with aspect ratios between 0.47 and 0.87 have been used in the assessment. Two simplified methods from the ACI 349-01 standard [1] and one from the ASCE 43-05 standard [2] have been evaluated. This paper also presents the development of an adjustment factor to consider the aspect ratio and the development of two approaches to consider interaction effects for one of the simplified methods. It concludes with the insights on the applicability of the code methods when interaction effects exist.
Date: June 1, 2008
Creator: Nie,J.; Xu, J.; Hofmayer, C. & Ali, S.
Partner: UNT Libraries Government Documents Department

Hard probes of short-range nucleon-nucleon correlations

Description: The strong interaction of nucleons at short distances leads to a high-momentum component to the nuclear wave function, associated with short-range correlations between nucleons. These short-range, high-momentum structures in nuclei are one of the least well understood aspects of nuclear matter, relating to strength outside of the typical mean-field approaches to calculating the structure of nuclei. While it is difficult to study these short-range components, significant progress has been made over the last decade in determining how to cleanly isolate short-range correlations in nuclei. We have moved from asking if such structures exist, to mapping out their strength in nuclei and studying their microscopic structure. A combination of several different measurements, made possible by high-luminosity and high-energy accelerators, coupled with an improved understanding of the reaction mechanism issues involved in studying these structures, has led to significant progress, and provided significant new information on the nature of these small, highly-excited structures in nuclei. We review the general issues related to short-range correlations, survey recent experiments aimed at probing these short-range structures, and lay out future possibilities to further these studies.
Date: October 1, 2012
Creator: J. Arrington, D. W. Higinbotham, G. Rosner, M. Sargsian
Partner: UNT Libraries Government Documents Department

Parity Violation Workshop - CEBAF

Description: This paper discusses the use of electron scattering experiments for exploring parity violation in the nuclear domain. It is shown how such experiments can test the structure of strong interactions, the local gauge theory quantum chromodynamics based on color, and the unified gauge theory of electroweak interactions.
Date: December 1, 1986
Creator: Walecka, J.
Partner: UNT Libraries Government Documents Department

Heavy Quark Symmetry

Description: New symmetries of the strong interactions appear in heavy quark physics. They can be used to predict many properties of hadrons containing a single heavy quark. Some of these predictions are expected to play an important role in determining the values of elements of the Cabibbo-Kobayashi-Maskawa matrix.
Date: June 1, 1992
Creator: Wise, Mark & Isgur, Nathan
Partner: UNT Libraries Government Documents Department

Hadron Physics at the New CW Electron Accelerators

Description: Major trends of the physics program related to the study of hadron structure and hadron spectroscopy at the new high current, high duty cycle electron machines are discussed. It is concluded that planned experiments at these machines may have important impact on our understanding of the strong interaction by studying the internal structure and spectroscopy of the nucleon and lower mass hyperon states.
Date: September 1, 1990
Creator: Burkert, Volker
Partner: UNT Libraries Government Documents Department

Inelastic final-state interaction

Description: The final-state interaction in multichannel decay processes is systematically studied with application to B decay in mind. Since the final-state interaction is intrinsically interwoven with the decay interaction in this case, no simple phase theorem like"Watson's theorem" holds for experimentally observed final states. We first examine in detail the two-channel problem as a toy-model to clarify the issues and to remedy common mistakes made in earlier literature. Realistic multichannel problems are too challenging for quantitative analysis. To cope with mathematical complexity, we introduce a method of approximation that is applicable to the case where one prominent inelastic channel dominates over all others. We illustrate this approximation method in the amplitude of the decay B to pi K fed by the intermediate states of a charmed meson pair. Even with our approximation we need more accurate information of strong interactions than we have now. Nonetheless we are able to obtain some insight in the issue and draw useful conclusions on general features on the strong phases.
Date: October 29, 2007
Creator: Suzuki, Mahiko & Suzuki, Mahiko
Partner: UNT Libraries Government Documents Department

Search for Electromagnetic Production of Fractionally Charged Particles at NAL

Description: One of the most important investigations to be conducted during the early operation of NAL is the search for quarks. Several experiments have been proposed which will investigate quark production via the strong interaction. As we discuss below, however, there are serious arguments to suggest that the mass limits obtained will not be significantly higher than the current limits of 4 to 5 GeV. To circumvent these objections we propose a simple experiment based on e1ectromagnetic production of quarks. It would run inside the main ring with photons produced in the rotating c-o target. No presently approved quark experiment is sensitive to such production without modification of its proposed set-up.
Date: April 13, 1972
Creator: McFarland, A.; Osuch, J.; Pilcher, J.; Rubbia, C.; Sulak, L.; Verhey, L. et al.
Partner: UNT Libraries Government Documents Department

Interaction between point defects and edge dislocation in BCC iron

Description: We present results of atomistic simulations of the interaction between self interstitial atoms and vacancies with edge dislocations in BCC iron. The calculations are carried out using molecular dynamics with an energy minimization scheme based on the quasi-Newton approach and use the Finnis-Sinclair interatomic potential for BCC iron developed by Ackland et al. Large anisotropy in the strain field of self interstitials is observed and it causes strong interaction with edge dislocations even when the defect is located on the dislocation glide plane. For vacancies, the relaxation volume is smaller and much more isotropic, which results in a far weaker interaction with the dislocation. A temperature dependent capture radius for vacancies and self interstitials is extracted from the simulations. The difference between the capture radii of vacancies and self interstitials is used to define the sink strength of the dislocation. Large deviations are observed from the predictions of elasticity based on treating point defects as isotropic dilatational centers. Further, the capture radius of edge dislocations in BCC iron is observed to be small and is of the order of l-3 nm for self interstitials.
Date: October 12, 1998
Creator: Diaz de la Rubia, T. & Shastry, V.
Partner: UNT Libraries Government Documents Department

Beauty and charm production at fixed-target experiments

Description: Fixed-target experiments continue to provide insights into the physics of particle production in strong interactions. The experiments are performed with different types of beam particles of varying energies, and many different target materials. Studies of beauty and charm production are of particular interest, since experimental results can be compared to perturbative QCD calculations. It is in this context that recent results from fixed-target experiments on beauty and charm production will be reviewed.
Date: December 10, 2003
Creator: Gottschalk, Erik E.
Partner: UNT Libraries Government Documents Department

Beauty, charm and hyperon production at fixed-target experiments

Description: Over the years fixed-target experiments have performed numerous studies of particle production in strong interactions. The experiments have been performed with different types of beam particles of varying energies, and many different target materials. Since the physics of particle production is still not understood, ongoing research of phenomena that we observe as beauty, charm and strange-particle production is crucial if we are to gain an understanding of these fundamental processes. It is in this context that recent results from fixed-target experiments on beauty, charm, and hyperon production will be reviewed.
Date: December 11, 2002
Creator: Gottschalk, Erik
Partner: UNT Libraries Government Documents Department

Studies of the strong and electroweak interactions at the Z{sub 0} pole

Description: This thesis presents studies of the strong and electroweak forces, two of the fundamental interactions that govern the behavior of matter at high energies. The authors have used the hadronic decays of Z{sup 0} bosons produced with the unique experimental apparatus of the e{sup +}e{sup {minus}} Linear Collider at the Stanford Linear Accelerator Center (SLAC) and the SLAC Large Detector (SLD) for these measurements. Employing the precision tracking capabilities of the SLD, they isolated samples of Z{sup 0} events containing primarily the decays of the Z{sup 0} to a chosen quark type. With an inclusive selection technique, they have tested the flavor independence of the strong coupling, {alpha}{sub s} by measuring the rates of multi-jet production in isolated samples of light (uds), c, and b quark events. They find: {alpha}{sub s}{sup uds}/{alpha}{sub s}{sup all} 0.987 {+-} 0.027(stat) {+-} 0.022(syst) {+-} 0.022(theory), {alpha}{sub s}{sup c}/{alpha}{sub s}{sup all} = 1.012 {+-} 0.104(stat) {+-} 0.102(syst) {+-} 0.096(theory), {alpha}{sub s}{sup b}/{alpha}{sub s}{sup all} = 1.026 {+-} 0.041(stat) {+-} 0.030(theory), which implies that the strong interaction is independent of quark flavor within the present experimental sensitivity. They have also measured the extent of parity-violation in the Z{sup 0} c{bar c} coupling, given by the parameter A{sub c}{sup 0}, using a sample of fully and partially reconstructed D* and D{sup +} meson decays and the longitudinal polarization of the SLC electron beam. This sample of charm quark events was derived with selection techniques based on their kinematic properties and decay topologies. They find A{sub c}{sup 0} = 0.73 {+-} 0.22(stat) {+-} 0.10(syst). This value is consistent with that expected in the electroweak standard model of particle interactions.
Date: March 1, 1995
Creator: Hildreth, M.D.
Partner: UNT Libraries Government Documents Department

Introduction to lattice QCD

Description: The goal of the lectures on lattice QCD (LQCD) is to provide an overview of both the technical issues and the progress made so far in obtaining phenomenologically useful numbers. The lectures consist of three parts. The author`s charter is to provide an introduction to LQCD and outline the scope of LQCD calculations. In the second set of lectures, Guido Martinelli will discuss the progress they have made so far in obtaining results, and their impact on Standard Model phenomenology. Finally, Martin Luescher will discuss the topical subjects of chiral symmetry, improved formulation of lattice QCD, and the impact these improvements will have on the quality of results expected from the next generation of simulations.
Date: December 1998
Creator: Gupta, R.
Partner: UNT Libraries Government Documents Department

Extracting {ital alpha}{sub s}from Tevatron data

Description: In this contribution we explore one of the many possibilities of determining the strong coupling constant {alpha}{sub s} at hadron colliders. The method considered is quite unique compared to other methods in that the value of {alpha}{sub s} is determined by the ``evolution rate`` of the parton density functions rather than by the ``event rate``.
Date: July 1, 1997
Creator: Giele, W.T.
Partner: UNT Libraries Government Documents Department

ULTRA-RELATIVISTIC NUCLEI: A NEW FRONTIER

Description: The collisions of ultra-relativistic nuclei provide a window on the behavior of strong interactions at asymptotically high energies. They also will allow the authors to study the bulk properties of hadronic matter at very high densities.
Date: October 29, 1999
Creator: MCLERRAN,L.
Partner: UNT Libraries Government Documents Department

Strong dynamics at the muon collider: Working group report

Description: New strong dynamics at the energy scale {approx} 1 TeV is an attractive and elegant theoretical ansatz for the origin of electroweak symmetry breaking. We review here, the theoretical models for strong dynamics, particularly, technicolor theories and their low energy signatures. We emphasize that the fantastic beam energy resolution ({sigma}{sub E}/E {approximately} 10{sup -4}) expected at the first muon collider ({radical}s=100-500 GeV) allows the possibility of resolving some extraordinarily narrow technihadron resonances and, Higgs-like techniscalars produced in the s-channel. Investigating indirect probes for strong dynamics such as search for muon compositeness, we find that the muon colliders provide unparalleled reaches. A big muon collider ({radical}s=3-4 TeV) would be a remarkable facility to study heavy technicolor particles such as the topcolor Z`, to probe the dynamics underlying fermion masses and mixings and to fully explore the strongly interacting electroweak sector.
Date: March 1, 1998
Creator: Bhat, P. C. & Eichten, E.
Partner: UNT Libraries Government Documents Department