Color Transparency Effects in Electron Deuteron Interactions at Intermediate Q^2

High momentum transfer electrodisintegration of polarized and unpolarized deuterium targets, $d(e,e'p)n$ is studied. We show that the importance of final state interactions-FSI, occuring when a knocked out nucleon interacts with the other nucleon, depends strongly on the momentum of the spectator nucleon. In particular, these FSI occur when the essential contributions to the scattering amplitude arise from internucleon distances $\sim 1.5~fm$. But the absorption of the high momentum $\gamma^*$ may produce a point like configuration, which evolves with time. In this case, the final state interactions probe the point like configuration at the early stage of its evolution. The result is that significant color transparency effects, which can either enhance or suppress computed cross sections, are predicted to occur for $\sim 4 GeV^2 \ge Q^2\leq~10~(GeV/c)^2$.Comment: 37 pages LaTex, 12 uuencoded PostScript Figures as separate file, to be published in Z.Phys.

Investigation of the high momentum component of nuclear wave function using hard quasielastic A(p,2p)X reactions

We present theoretical analysis of the first data on the high energy and momentum transfer (hard) quasielastic $C(p,2p)X$ reactions. The cross section of hard $A(p,2p)X$ reaction is calculated within the light-cone impulse approximation based on two-nucleon correlation model for the high-momentum component of the nuclear wave function. The nuclear effects due to modification of the bound nucleon structure, soft nucleon-nucleon reinteraction in the initial and final states of the reaction with and without color coherence have been considered. The calculations including these nuclear effects show that the distribution of the bound proton light-cone momentum fraction $(\alpha)$ shifts towards small values ($\alpha < 1$), effect which was previously derived only within plane wave impulse approximation. This shift is very sensitive to the strength of the short range correlations in nuclei. Also calculated is an excess of the total longitudinal momentum of outgoing protons. The calculations are compared with data on the $C(p,2p)X$ reaction obtained from the EVA/AGS experiment at Brookhaven National Laboratory. These data show $\alpha$-shift in agreement with the calculations. The comparison allows also to single out the contribution from short-range nucleon correlations. The obtained strength of the correlations is in agreement with the values previously obtained from electroproduction reactions on nuclei.Comment: 30 pages LaTex file and 19 eps figure

The Role of Color Neutrality in Nuclear Physics--Modifications of Nucleonic Wave Functions

The influence of the nuclear medium upon the internal structure of a composite nucleon is examined. The interaction with the medium is assumed to depend on the relative distances between the quarks in the nucleon consistent with the notion of color neutrality, and to be proportional to the nucleon density. In the resulting description the nucleon in matter is a superposition of the ground state (free nucleon) and radial excitations. The effects of the nuclear medium on the electromagnetic and weak nucleon form factors, and the nucleon structure function are computed using a light-front constituent quark model. Further experimental consequences are examined by considering the electromagnetic nuclear response functions. The effects of color neutrality supply small but significant corrections to predictions of observables.Comment: 37 pages, postscript figures available on request to [email protected]

Nuclear transparency from quasielastic A(e,e'p) reactions uo to Q^2=8.1 (GeV/c)^2

The quasielastic (e,e$^\prime$p) reaction was studied on targets of deuterium, carbon, and iron up to a value of momentum transfer $Q^2$ of 8.1 (GeV/c)$^2$. A nuclear transparency was determined by comparing the data to calculations in the Plane-Wave Impulse Approximation. The dependence of the nuclear transparency on $Q^2$ and the mass number $A$ was investigated in a search for the onset of the Color Transparency phenomenon. We find no evidence for the onset of Color Transparency within our range of $Q^2$. A fit to the world's nuclear transparency data reflects the energy dependence of the free proton-nucleon cross section.Comment: 11 pages, 6 figure

Extending the CARE Principles from tribal research policies to benefit sharing in genomic research

Indigenous Peoples have historically been targets of extractive research that has led to little to no benefit. In genomics, such research not only exposes communities to harms and risks of misuse, but also deprives such communities of potential benefits. Tribes in the US have been exercising their sovereignty to limit this extractive practice by adopting laws and policies to govern research on their territories and with their citizens. Federally and state recognized tribes are in the strongest position to assert research oversight. Other tribes lack the same authority, given that federal and state governments do not recognize their rights to regulate research, resulting in varying levels of oversight by tribes. These governance measures establish collective protections absent from the US federal government’s research oversight infrastructure, while setting expectations regarding benefits to tribes as political collectives. Using a legal epidemiology approach, the paper discusses findings from a review of Tribal research legislation, policy, and administrative materials from 26 tribes in the US. The discussion specifies issues viewed by tribes as facilitators and barriers to securing benefits from research for their nations and members/citizens, and describes preemptive and mitigating strategies pursued by tribes in response. These strategies are set within the framing of the CARE Principles for Indigenous Data Governance (Collective Benefit, Authority to Control, Responsibility, Ethics), a set of standards developed to ensure that decisions made about data pertaining to Indigenous communities at the individual and tribal levels are responsive to their values and collective interests. Our findings illustrate gaps to address for benefit sharing and a need to strengthen Responsibility and Ethics in tribal research governance. Copyright © 2022 Carroll, Plevel, Jennings, Garba, Sterling, Cordova-Marks, Hiratsuka, Hudson and Garrison.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Scalability and robustness of a network resource allocation system using market-based agents

agent, communications network, market, resource allocation, scalability, robustness,