Michael Antonio Barnett

The reaction e− + 3He → νe + 3H and the determination of the weak nuclear form factors

Abstract We calculate the differential cross section for the weak electron scattering process, e − + 3 He → ν e + 3 H , for a variety of energies from 0.1 to 6.0 GeV. We note that the maximum of the differential cross section increases with increasing electron energy but that the width of the peak at half maximum rapidly shrinks. The contributions of the individual nuclear form factors to the cross section are also obtained and the possibility of determining them via electron accelerator experiments is discussed.

The many faces of rasta : Doctrinal diversity within the rastafari movement

Of recent much has been written about the Rastafari movement in general, especially since the publication of the University of the West Indies Report on the movement in 1960. Overwhelmingly however, the view that is presented is that of a monolithic, homogeneous movement. This paper seeks to challenge this popular misconception by speaking to the matter of the existence of the many doctrinal, theological and even ideological differences between the various mansions of Rastafari. (Of course there are commonalities between the mansions, but in reality there are very few.) Any serious consideration of the movement should address the ideological and theological perspectives of each mansion, rather than attempting to generalize for the movement as a whole. The three primary mansions of the movement that are considered in this paper are: the Nyahbinghi mansion, the Boboshante mansion and the Twelve Tribes of Israel mansion. In addition there will be limited consideration of a mansion that is generally considered as being marginal to the Rastafari movement, namely that of the Ethiopian Coptic Church.

Differences and Similarities Between the Rastafari Movement and the Nation of Islam

The two Black social movements under consideration in this article are now well established among Black communities in America and, although widely thought to be distinct from each other, have much in common. As such, this article seeks to explore the similarities and differences between the movements. One overarching similarity is that both movements empower their largely Black adherents by providing them with a positive Black identity. This may be viewed as an outcome of both movements being inspired by Marcus Garvey. In addition, because these movements emphasize change within the individual rather than change in the surrounding social structure, they are considered to be expressive social movements. A key difference between the movements is the specific type of positive Black identity that is inculcated. For the Rastafari movement, it is an African-centered, Afrocentric identity, whereas for the Nation of Islam it is a Blackcentric identity (that is not geographically anchored).

Polarized parity violating electron scattering on 3He

Abstract We calculate the asymmetry parameters, A, and figures-of-merit for polarized parity violating electron scattering from 3He via the reaction, e− +3 He → e− +3 He. We do this explicitly forv incident electron energies of 1.0 GeV and 4.0 GeV. We find a sharp and unexpected variation in A due to cancellations between the weak and electromagnetic form factors caused by the different q2 dependences of these form factors. We find that at small angles, the asymmetry may be obtained to reasonably high accuracy for all energies considered and that the interesting region where the asymmetry has its first maximum and minimum is accessible for electron energies of 1 GeV or higher. In addition we find that the asymmetry and figures-of-merit are in the range of those for other proposed target nuclei. We also consider the possibility of strange quark contributions to the asymmetry and show that at the first maxima and minima, possible contributions of the strange quark current vector form factors cause large variations in the asymmetry which might be observed.

Polarized parity violating electron scattering in 3He and 3H

We calculate the asymmetry parameter, A, for the electron scattering reaction, e+3He→e+3He, run with right and left handed polarized electrons. We have calculated this reaction at energies from .1 GeV to 6 GeV. We present here the results for this reaction run at 1 GeV as an example. We obtain both A and a figure of merit. We find a sharp and unexpected variation in A due to cancellation between the weak and electromagnetic form factors. This is caused by the different q2 dependences of the weak and electromagnetic form factors. Unfortunately in this region the figure of merit is small.

The Weak Production of Lambda Particles in Electron and Muon Scattering from Protons from Near Threshold to the 5.0 GeV Region

We calculate the differential cross sections for the weak strangeness changing reactions e− + p → Λ + ve and μ− + p → vμ + Λ. We study the former reaction for energies near threshold and we study the later reaction from energies near threshold to 5.0 GeV. We do this because the electron induced reaction has been proposed as possible experiment at the Thomas Jefferson National Accelerator Facility by which the electron neutrino mass might be measured. We study the muon induced reaction over a wider range of energies because it might be used to study form factors which are more difficult or impossible to observe in an electron induced reactions due to the small size of the electron mass. In particular we obtain the induced pseudoscalar form factor contributions to the differential cross section as well as the contributions of the FE and FS form factors to try to determine if it is feasible to observe them. We use an SU(3) based semi‐phenomenological calculation to obtain the form factors from electron scatt...

The Reaction μ− + p → Λ + vμ and the Contributions of the Pseudoscalar Form Factor

We calculate the differential cross section for the weak, strangeness changing, muon scattering process, μ− + p → vμ + Λ, for incoming muon energies of 2.0,0.275 and 0.265 GeV. We obtain as well contributions of the individual form factors to the differential cross sections but focus on the pseudocalar form factor which has not been well studied in strangeness changing processes. In particular we assess the possibility of observing pseudoscalar form factor contributions at low q2 where the mass of the muon may accentuate these contributions. We find that the differential cross sections peak as the maximal scattering angle for the Λ is approached and that the peak height increases as the muon energy is increased. The behavior of the differential cross section near the maximal angle is discussed as is the possibility of observing second class current form factors.

Neutrino and Anti-Neutrino Reactions in Nuclei

The last year or two in neutrino-nuclei interactions has been spent in expectant and hopeful waiting rather than in striking new results. Perhaps the most interesting results have been from LAMPF for the inclusive muon neutrino reaction, v μ + 12 C → X + μ −, and for the corresponding exclusive reaction v μ + 12 C → μ− + 12 N (g.s.). Here the relatively low cross section for the inclusive reaction has persisted and their measurement of the exclusive cross section is in good agreement with theory thus putting to rest some questions which have been raised. We shall discuss this in more detail later in this paper. The KARMEN collaboration continues to obtain data and their results for both inclusive and exclusive electron neutrino reactions on l2 C are in reasonable agreement with theory. New data from kamiokande II is beginning to appear but there is no definitive result yet. Finally the Sudbury Neutrino Observatory (SNO) is in its final phase of construction. We will have occasion to mention some of these experiments later.

Weak Interactions with Electron Machines a Survey of Possible Processes

The field of weak interactions is now a reasonably old one. The first beta decays were observed in the first part of the present century. By the 1930’s, a theory of beta decay of the current-current form had already been proposed by Fermi. By the 1950’s this work was extended by Feynman and Gell-Mann in the form of the V — A theory which was applicable to all weak first order processes. On a fundamental level in the next two decades the weak and electromagnetic interactions were combined and can be said to be understood on the quark level. This work was initiated by Weinberg, Salam, and Glashow and along with quantum chromodynamics forms the basis of what is called the standard model. This model, while clearly not fundamental, has done very well at meeting many tests and is the present established model.