Spin Test Research Articles

Crucial spin tests of quantum-chromodynamic approaches to large-transverse-momentum processes

The polarization of the large-${p}_{T}$ reaction $p+p\ensuremath{\rightarrow}\ensuremath{\pi}+X$ is shown to vanish if the perturbative quantum-chromodynamical approach is used. The status of two-spin correlation studies of large-${p}_{T}$ inclusive production processes is clarified, the usefulness of spin correlations of the reaction $p+p\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}+{\ensuremath{\pi}}^{+}+X$ in revealing the nature of constituent scattering is discussed, whereas the reaction $p+p\ensuremath{\rightarrow}\ensuremath{\pi}+X$ is less useful for this purpose.

A 2.5-MVA High-Voltage Lightweight Generator

The design and development of a 2.5-MVA, 13,600 rpm, air-cooled, 2887/5000-V, 680-Hz, lightweight generator for helicopter application is discussed. The generator is a brushless machine designed to have a maximum weight of 1500 Ib. The high-voltage insulation system, the mechanical design of the high-speed rotor, the electromagnetic design, the thermal analyses, and the squeeze-film damper system which facilitates operation above the first and second critical speeds are discussed. High-voltage insulation endurance test and rotor spin test results are also presented.

Baryon spin-parity tests using polarized proton targets or beams

A new method is proposed for performing combined spin and parity tests on baryon resonances generated in quasi-two-body production experiments, without any dynamical hypothesis, using polarized proton targets or beams. These tests present the advantage of being applicable to data averaged over intervals of momentum transfer and mass. In order to estimate the sensitivity of the tests to experimental errors, a simulated experiment with random errors is analysed, and quite good stability is found.

A spin determination of the Ξ ∗ (1820) resonance

Using a spin test proposed recently by Minnaert, we determine the spin of the Ξ ∗ (1820) resonance to be 3 2 .

Spin tests for charmed mesons produced ine+e−annihilation ats=4.028GeV

Spin tests for particles produced in e/sup +/e/sup -/ annihilation at ..sqrt..s = 4.028 GeV in the state labeled D-bar*D* are presented. These particles are currently believed to be spin-1 particles with negative parity. However, their extraordinarily large production rate just above their production threshold: despite the p-wave nature of the production process-leads us to speculate that one of these might, in fact, be a spinless, positive-parity D meson with a mass approximately the same as the D*. This possibility is considered and tested in detail, along with the usual hypothesis that the particles are spin-1 particles.

Abstract: Novel spin test for adherence, wear resistance, and thermal shock of thin films

Abstract: Novel spin test for adherence, wear resistance, and thermal shock of thin films

Progress on Ceramic Rotor Blade Development for Industrial Gas Turbines

This paper reviews progress made in the first year of a three-year program sponsored by EPRI to design and test ceramic root attachments, leading to the full development of ceramic rotor blades and cantilevered vanes intended for industrial gas turbines. Initial work has focused on a rotor blade attachment design. The specific rotor configuration chosen for development consists of a cooled low-alloy steel disk, a cooled intermediate super-alloy attachment piece, an uncooled ceramic blade, and the provision for a compliant interface at the ceramic/metal root attachment. A new root attachment design, in which the root and groove are curved in their transverse and longitudinal directions, is presented. Room temperature spin tests of dovetail root forms have provided encouraging results and indicate that continued development is warranted.

Boson spin tests from sequential decays spin-parity analysis of the F 1 meson

The paper contains two parts. In part A a complete set of spin-parity test from angular correlations and positivity conditions in the sequential decay J P → 1 −0 −, 1 − → 0 −0 − is established. In part B these tests are applied to the F 1 meson produced in the reaction pp → F 1ω at an average value of momentum 1.7 GeV/ c. The analysis of the joint decay of the final state F 1 → K ∗ K, K ∗ → Kπ and ω → π +π −π 0 indicates that the spin-parity J P of the F 1 belongs to the abnormal series. It excludes the possibility J P = 1 + and favours strongly the assignment J P = 2 −.

Spin test ofη′(958)from its collinear production and collinear decay

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A new spin test for the equivalence principle

The existing impressive tests for the strong equivalence principle are reviewed and their classical nature is emphasized. The possibility is raised here that intrinsic quantum spins may behave differently from orbital angular momentum in gravitational fields. The techniques developed to measure the electric dipole moment of the neutron are shown to offer hopes of testing this hypothesis. Einstein's theory predicts a null result for this experiment. This would constitute the first quantum test for the strong equivalence principle. Deviation from a null result would invalidate Einstein's theory of gravitation, as well as indicate the failure of the discrete symmetries (P, T) in gravitation.

Spin tests for the Ξ ∗ (1820) resonance

Spin tests are derived for the Ξ ∗− (1820) resonance from a comparison of its two main decay modes Ξ ∗− (1820) → Λ 0K − and Ξ ∗o (1530) π −.

Spin tests for intermediate states in radiativeψ′(3684)decay chains

Analysis of the multiple angular-correlation functions for the sequential decays ${\ensuremath{\psi}}^{\ensuremath{'}}({1}^{\ensuremath{-}})\ensuremath{\rightarrow}\ensuremath{\gamma}+\ensuremath{\chi}$,$\ensuremath{\chi}\ensuremath{\rightarrow}M\overline{M}$, where $M$ is a spinless meson, and ${\ensuremath{\psi}}^{\ensuremath{'}}({1}^{\ensuremath{-}})\ensuremath{\rightarrow}{\ensuremath{\gamma}}_{1}+\ensuremath{\chi}$,$\ensuremath{\chi}\ensuremath{\rightarrow}{\ensuremath{\gamma}}_{2}+\ensuremath{\psi}$, $\ensuremath{\psi}({1}^{\ensuremath{-}})\ensuremath{\rightarrow}l\overline{l}$, when the ${\ensuremath{\psi}}^{\ensuremath{'}}$ is formed in ${e}^{+}{e}^{\ensuremath{-}}$ collisions, shows that these can unambiguously distinguish between the spin assignments ${s}_{\ensuremath{\chi}}=0. 1, or 2$ for the intermediate states occuring in these decays, as well as determine the multipole amplitudes contributing to the radiative transitions. No dynamical assumptions are made beyond the conservation of angular momentum and parity; recoils are fully taken into account.

Rigorous spin tests from angular distribution of single two-body decays

We extend to the several-amplitude decays j→ j 1+ j 2, ( j⩾ j 1+ j 2, j 1+ j 2⩽2) the rigorous spin tests given by Doncel, Michel and Minnaert for the usual one-amplitude strong decays, in quadrupole and quadrupole-hexadecapole spaces. We also derive spin tests in dipole-quadrupole space for the parity violating decays j → 1 2 0 and j → 1 2 1 2 .

Spin tests from angular correlations in sequential decays

We formulate precisely the principle of spin tests from angular correlations in sequential decays. We show that the spin tests for bosons proposed by Ademollo, Gatto, and Preparata for canonical frames and by Berman, Jacob, and Chung for helicity frames are equivalent.

Spin tests and amplitude analysis for the reaction0+12→0+J

A complete set of equations is found which relate the spin $J$ of a fermion resonance, certain bilinear forms in the statistical tensors ${t}_{L}^{M}$ with $L$ even), and the degree of target polarization for the reaction $0+\frac{1}{2}\ensuremath{\rightarrow}0+J$ on a polarized target. For the case of production on an unpolarized target, the helicity amplitudes, to within a four-parameter ambiguity, are explicitly constructed from the even-$L$ ${t}_{L}^{M}$ and a complete set of trilinear constraints among the latter is obtained.

Rigorous spin tests from two-amplitude strong decays

We extend to two-amplitude strong decays ( j → 1 0, j → 2 0, j → 3 2 0 ) the rigorous spin tests given by Doncel, Michel and Minnaert for the usual one-amplitude strong decays.

Fighter testing—spin test or spin prevention test?

One of the severest operational limitations of a fighter is high angle of attack. I would like to discuss a philosophy of requirements on approach to testing and aircraft improvement. I will also summarise the results of the recent USAF, F-4E Stall/Near Stall Investigation.For review, consider the classic approach used to testing at high angle of attack. All fighters are stall tested, i.e. a determination of handling qualities is made up to maximum usable lift. This, of course, also involves determination of natural stall warning, stall speeds and stall recovery techniques. Testing at angles of attack above maximum usable lift is generally delayed until a spin test programme is accomplished.

Rigorous spin tests from usual strong decays

Applying our geometrical formalism, we make a general study of angular momentum and parity conservation in the most frequent two body strong decays, in order to propose new tests for the determination of the spin of the decaying particle.

A Field Method of Determining Gas Turbine Meter Performance

The need for a simple and inexpensive method for field checking gas turbine meters exists. One such method called the “spin test” is described in this paper. The relationship between the change of “rotor coast time” of the spin test and the change of meter accuracy due to change of mechanical friction is formulated. Experimental results on two different 6-in. gas turbine meters are presented and show good agreement with analytical results.

Spin test for resonances

A simple method to obtain from the decay angles information on the spin of a resonance is illustrated. The utility of the system is in its generality: indeed it can be applied also to not sequential many-body decays where we have not any other possibilities.