125859668
High-spin states of Jpi=12-, 14- in Pb-208 studied by (e, e-prime)
122290195
Off-shell effects in quasielastic electron nucleus scattering
Using the Ward-Takahashi identity, on-shell condition, bound Dirac equation and off-shell expansion, a reduced version of half off-shell virtual photon nucleon vertex has been suggested. The vertex are decomposed into several different order terms: the on-shell terms, first and second off-shell terms. The off-shell behaviour of the form factors is discussed in the one meson loop model. Using the reduced vertex and parametrized off-shell form factors the quasielastic response functions are calculated for several nuclei at ¦q¦–kf and for56Fe at large ¦q¦ up to 1.14 GeV/c and at −q2=0.9 (GeV/c)2. The Coulomb sums are evaluated and a comparison of the theoretical prediction with data is given. The off-shell electron nucleon cross section is calculated and compared with the “cc1” off-shell extrapolation.
32493630
Computer Modeling of Internal Targets in Electron Storage Rings
The effect of thin (1-50 ¿gm/cm2) internal targets on beam quality in electron storage rings is evaluated. The internal target is modeled assuming that scattering is the result of elastic collisions between the beam electrons and the target nuclei. A screened coulomb potential is used and single and plural scattering mechanisms are included. A storage ring particle tracking code, DIMAT, was modified to include the internal target model and used to obtain the results discussed. Beam particle loss distributions and beam envelope "growth times" are given and discussed in light of damping mechanisms inherent in electron storage ring designs.
121139038
CEBAF — a high energy, high duty factor electron accelerator for nuclear physics☆
Abstract The Nuclear Science Advisory Committee has recommended the construction of the Continuous Electron Beam Accelerator Facility (CEBAF) as proposed by the Southeastern Universities Research Association (SURA), a consortium of more than thirty institutions in the southeastern United States. The accelerator will be capable of delivering intense (Iave > 100 μA), quasi-continuous (duty Factor > 90%) beams of electrons with energies up to 4.8 GeV. Short (1.2 μs), intense (Ipk = 200 mA) pulses of electrons will be accelerated by passing twice through a conventional pulsed linac. The pulses then will be injected into and stored in a pulse stretcher ring, the circumference of which is close to the length of the electron pulse. During the period between pulses (1ms) the stored electrons will be extracted to yield a high duty factor beam. Delivery of arbitrarily polarized beams will be possible. Experimental facilities will include three end stations. Two will be used for experiments utilizing the primary electron beam; the third will serve as a tagged photon facility.
121665406
Quark-parton models and the neutron charge radius
120014689
Pion-helium scattering above the (3,3) resonance
Differential cross sections are reported for ..pi../sup +/+/sup 3,4/He elastic scattering at 260, 295, and 310 MeV and ..pi../sup -/+/sup 3,4/He at 295 MeV. The angular distributions )except for ..pi../sup -/+/sup 3/He) confirm the fixed angle (thetaapprox. =75/sup 0/) minimum seen at lower energies (caused by the (3,3) ..pi..+N resonance dominance) and show a deep minimum at thetaapprox. =110/sup 0/. Comparisons are made to ..pi..+d and the current discussion of pion excitation of intermediate dibaryon and ..delta..N states.
11851007
Fusing the coordinates of quantum superspace
Abstract We introduce the notion of a fused quantum superplane by allowing for terms θθ ∼ x in the defining relations. We develop the differential calculus for a large class of fused quantum superplanes related to particular solutions of the Yang-Baxter equation.
904429
Observation of the resonant character of the Z(4430)(-) state.
Resonant structures in B^{0}→ψ^{'}π^{-}K^{+} decays are analyzed by performing a four-dimensional fit of the decay amplitude, using pp collision data corresponding to 3  fb^{-1} collected with the LHCb detector. The data cannot be described with K^{+}π^{-} resonances alone, which is confirmed with a model-independent approach. A highly significant Z(4430)^{-}→ψ^{'}π^{-} component is required, thus confirming the existence of this state. The observed evolution of the Z(4430)^{-} amplitude with the ψ^{'}π^{-} mass establishes the resonant nature of this particle. The mass and width measurements are substantially improved. The spin parity is determined unambiguously to be 1^{+}.
23392178
Proton Extraction and Transport for Pbar Production in Tevatron I
The design, fabrication, and commissioning of the extraction and beam transport systems required for pbar production for the FNAL Antiproton Source will be described. The extraction system utilizes a fast kicker and Lambertson septum magnets to extract in a single turn one booster batch of 120 GeV protons from the FNAL Main Ring. The extracted beam is transported a distance of 174 m by a beam transport system consisting of 12 dipoles and 14 quadrupoles. The last 8 quadrupoles are configured as 4 pairs which focus the beam to a small round spot (radius 0.4 mm) on a pbar production target. The extraction channel is also designed to inject 8 GeV cooled pbars from the Accumulator Ring into the Main Ring, or extract 8 GeV protons from the Main Ring for diagnostic and tune-up work in the Antiproton Source beam lines and rings.
54960779
Measurement of the resonant and CP components in $\overline{B}^0\to J/\psi \pi^+\pi^-$ decays
The resonant structure of the reaction $\overline{B}^0\rightarrow J/\psi \pi^+\pi^-$ is studied using data from 3 fb$^{-1}$ of integrated luminosity collected by the LHCb experiment, one-third at 7 Tev center-of-mass energy and the remainder at 8 Tev. The invariant mass of the $\pi^+\pi^-$ pair and three decay angular distributions are used to determine the fractions of the resonant and non-resonant components. Six interfering $\pi^+\pi^-$ states: $\rho(770)$, $f_0(500)$, $f_2(1270)$, $\rho(1450)$, $\omega(782)$ and $\rho(1700)$ are required to give a good description of invariant mass spectra and decay angular distributions. The positive and negative CP fractions of each of the resonant final states are determined. The $f_0(980)$ meson is not seen and the upper limit on its presence, compared with the observed $f_0(500)$ rate, is inconsistent with a model of tetraquark substructure for these scalar mesons at the eight standard deviation level. In the $q\overline{q}$ model, the absolute value of the mixing angle between the $f_0(980)$ and the $f_0(500)$ scalar mesons is limited to be less than $17^{\circ}$ at 90% confidence level.
120816642
A mechanism for fermion mass generation
Abstract We present a mechanism for fermion mass generation, and apply it to the lepton sector of the Weinberg-Salam model. Extra fields, necessary to produce the large mass splittings of the observed fermions, form bound states more massive than the electroweak scale.