121044718
A Study of Correlations Between Identified Charged Hadrons in Hadronic Z0 Decays
We present a preliminary study of correlations in rapidity between pairs of identified charged pions, kaons and protons in the SLD data. Details of short-range charge correlations between all combinations of these hadron species are used to study the locality of quantum number conservation, and suggest local charge ordering along the entire hadronization chain. A strong long-range K{sup +}K{sup -} correlation is observed at high-momentum and weaker long-range {pi}{sup +}-{pi}{sup -}, {pi}{sup +}-K{sup -} and p-K{sup -} correlations are observed in light flavor events, providing new information on leading particle production in u, d and s jets. The long-range correlations observed in c{bar c} and b{bar b} events are markedly different and consistent with expectations based on known decay properties of the leading heavy hadrons. The SLC electron beam polarization is used to tag the quark hemisphere in each event, allowing the first study of rapidities signed relative to the quark (vs. antiquark) direction. Distributions of ordered, signed rapidity differences provide a new probes of the fragmentation process, including the first direct observation of baryon number ordering along the q {yields} {bar q} axis.
124860285
Review of c, b and τ Lifetimes from e+e- Experiments
The current status of lifetime measurements of heavy flavored particles by experiments at e + e - colliders and their implications for the standard model are reviewed. This includes the most recent measurents of lifetimes of the tau lepton, the D mesons and B hadrons. The emphasis is on B hadron lifetimes, since there are several new results contributed to this conference. The first use of the B lifetime to tag and study bƃ events is also discussed.
121044718
A Study of Correlations Between Identified Charged Hadrons in Hadronic Z0 Decays
We present a preliminary study of correlations in rapidity between pairs of identified charged pions, kaons and protons in the SLD data. Details of short-range charge correlations between all combinations of these hadron species are used to study the locality of quantum number conservation, and suggest local charge ordering along the entire hadronization chain. A strong long-range K{sup +}K{sup -} correlation is observed at high-momentum and weaker long-range {pi}{sup +}-{pi}{sup -}, {pi}{sup +}-K{sup -} and p-K{sup -} correlations are observed in light flavor events, providing new information on leading particle production in u, d and s jets. The long-range correlations observed in c{bar c} and b{bar b} events are markedly different and consistent with expectations based on known decay properties of the leading heavy hadrons. The SLC electron beam polarization is used to tag the quark hemisphere in each event, allowing the first study of rapidities signed relative to the quark (vs. antiquark) direction. Distributions of ordered, signed rapidity differences provide a new probes of the fragmentation process, including the first direct observation of baryon number ordering along the q {yields} {bar q} axis.
84154696
Results from PETRA on the Average Lifetime of B Hadrons
120017490
QCD studies of hadronic decays of Z0 bosons by SLD
Z0 bosons have been produced by collisions of longitudinally polarized electrons with unpolarized positrons at the SLAC Linear Collider and their decays have been recorded by the SLD experiment. We present preliminary QCD results based on the first 6000 such decays. We find good agreement between the inclusive properties of these data and the predictions of perturbative QCD plus fragmentation models. The strong coupling, αs, has been measured by three methods: jet rates yield αs(MZ)=0.119±0.002(stat.)±0.003(exp. syst.)±0.014(theor.); energy‐energy correlations yield αs(MZ)=0.121±0.002±0.004±0.0160.009; and the energy‐energy correlation asymmetry gives αs(MZ)=0.108±0.003±0.005±0.0080.003.
117111758
A study of jet handedness in hadronic Z0 decays
36454783
Casimir energy density in closed hyperbolic universes
The original Casimir effect results from the difference in the vacuum energies of the electromagnetic field, between that in a region of space with boundary conditions and that in the same region without boundary conditions. In this paper we develop the theory of a similar situation, involving a scalar field in spacetimes with closed spatial sections of negative curvature.
118472353
BIANCHI I SOLUTIONS OF EFFECTIVE QUADRATIC GRAVITY
It is believed that soon after the Planck time, Einstein's general relativity theory should be corrected to an effective quadratic theory. Numerical solutions for the anisotropic generalization of the Friedmann "flat" model E3 for this effective gravity are given. It must be emphasized that although numeric, these solutions are exact in the sense that they depend only on the precision of the machine. The solutions are identified asymptotically in a certain sense. It is found solutions which asymptote de Sitter space, Minkowski space and a singularity. This work is a generalization for nondiagonal spatial metrics of a previous result obtained by one of us and a collaborator for Bianchi I spaces.
119193340
The concept of phenomenological light-front wave functions -- Regge improved diquark model predictions
We introduce a classification scheme for parton distribution models and we model generalized parton distributions (GPDs), their form factors, and parton distribution functions (PDFs), integrated and unintegrated ones, in terms of unintegrated double distributions that are obtained from the parton number conserved overlap of effective light-front wave functions. For a so-called "spherical" model we present general expressions for all twist-two related non-perturbative quantities in terms of one effective light-front wave function, including chiral-odd GPDs. We also discuss the Regge improvement of such quark models from the $s$-channel point of view and study the relations between zero-skewness GPDs and unintegrated PDFs on a more general ground. Finally, we provide a few phenomenological applications that emphasize the role of orbital angular momenta.
118937097
Numerical Bianchi type I solutions in semiclassical gravitation
It is believed that soon after the Planck era, spacetime should have a semiclassical nature. In this context we consider quantum fields propagating in a classical gravitational field and study the backreaction of these fields, using the expected value of the energy-momentum tensor as source of the gravitational field. According to this theory, the escape from general relativity theory is unavoidable. Two geometric counter-term are needed to regularize the divergences which come from the expected value. There is a parameter associated to each counter-term and in this work we found numerical solutions of this theory to particular initial conditions, for general Bianchi Type I spaces. We show that even though there are spurious solutions some of them can be considered physical. These physical solutions include de Sitter and Minkowski that are obtained asymptotically.
13486962
Wave functions, evolution equations and evolution kernels from light ray operators of QCD
The widely used nonperturbative wave functions and distribution functions of QCD are determined as matrix elements of light-ray operators. These operators appear as large momentum limit of non-local hadron operators or as summed up local operators in light-cone expansions. Nonforward one-particle matrix elements of such operators lead to new distribution amplitudes describing both hadrons simultaneously. These distribution functions depend besides other variables on two scaling variables. They are applied for the description of exclusive virtual Compton scattering in the Bjorken region near forward direction and the two meson production process. The evolution equations for these distribution amplitudes are derived on the basis of the renormalization group equation of the considered operators. This includes that also the evolution kernels follow from the anomalous dimensions of these operators. Relations between different evolution kernels (especially the Altarelli-Parisi and the Brodsky-Lepage kernels) are derived and explicitly checked for the existing two-loop calculations of QCD. Technical basis of these results are support and analytically properties of the anomalous dimensions of light-ray operators obtained with the help of the α-representation of Green's functions.