Special Research Centre for the Subatomic Structure of Matter

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https://hdl.handle.net/2440/10825

The central mission of the Centre is to carry out research activities in the forefront of the fields of theoretical nuclear and particle physics with special emphasis on the strong interactions and their importance in determining the nature of matter.

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Rm. 126, Lvl 1 Physics Building,
University of Adelaide,
SA 5005, Australia
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Browsing Special Research Centre for the Subatomic Structure of Matter by Author "Afnan, I."

Now showing 1 - 6 of 6
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    Comment on "Parton distributions, d/u, and higher twist effects at high x"
    (American Physical Soc, 2000) Melnitchouk, W.; Afnan, I.; Bissey, F.; Thomas, A.; Special Research Centre for the Subatomic Structure of Matter
    A Comment on the Letter by U. K. Yang and A. Bodek, Phys. Rev. Lett. 82, 2467 (1999). The authors of the Letter offer a Reply. © 2000 The American Physical Society.
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    Deep inelastic scattering from A =3 nuclei and the neutron structure function
    (American Physical Soc, 2003) Afnan, I.; Bissey, F.; Gomez, J.; Katramatou, A.; Liuti, S.; Melnitchouk, W.; Petratos, G.; Thomas, A.
    We present a comprehensive analysis of deep inelastic scattering from ³He and ³H, focusing in particular on the extraction of the free neutron structure function F₂n. Nuclear corrections are shown to cancel to within 1–2% for the isospin-weighted ratio of ³He to ³H structure functions, which leads to more than an order of magnitude improvement in the current uncertainty in the neutron to proton ratio ₂2n/F₂p at large x. Theoretical uncertainties originating from the nuclear wave function, including possible non-nucleonic components, are evaluated. Measurements of the ³He and ³H structure functions will, in addition, determine the magnitude of the EMC effect in all A<~3 nuclei.
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    Deep inelastic scattering on asymmetric nuclei
    (Elsevier Science BV, 2000) Saito, K.; Boros, C.; Tsushima, K.; Bissey, F.; Afnan, I.; Thomas, A.
    We study deep inelastic scattering on isospin asymmetric nuclei. In particular, the difference of the nuclear structure functions and the Gottfried sum rule for the lightest mirror nuclei, 3He and 3H, are investigated. It is found that such systems can provide significant information on charge symmetry breaking and flavor asymmetry in the nuclear medium. Furthermore, we propose a new method to extract the neutron structure function from radioactive isotopes far from the line of stability. We also discuss the flavor asymmetry in the Drell-Yan process with isospin asymmetric nuclei. (C) 2000 Elsevier Science B.V.
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    Extracting nucleon spin structure functions from nuclear data
    (Institute of Physical and Chemical Research, 2000) Thomas, A.; Afnan, I.; Bissey, F.
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    Neutron structure function and A = 3 mirror nuclei
    (Elsevier Science BV, 2000) Afnan, I.; Bissey, F.; Gomez, J.; Katramatou, A.; Melnitchouk, W.; Petratos, G.; Thomas, A.
    We investigate deep inelastic scattering from 3He and 3H within a conventional convolution treatment of binding and Fermi motion effects. Using realistic Faddeev wave functions together with a nucleon spectral function, we demonstrate that the free neutron structure function can be extracted in deep-inelastic scattering from A = 3 mirror nuclei, with nuclear effects canceling to within 2% for x ≤ 0.85. (C) 2000 Elsevier Science B.V.
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    Structure functions for the three-nucleon system
    (American Physical Soc, 2001) Bissey, F.; Thomas, A.; Afnan, I.
    The spectral functions and light-cone momentum distributions of protons and neutrons in ³He and ³H are given in terms of the three-nucleon wave function for realistic nucleon-nucleon interactions. To reduce computational complexity, separable expansions are employed for the nucleon-nucleon potentials. The results for the light-cone momentum distributions suggest that they are not very sensitive to the details of the two-body interaction, as long as it has reasonable short-range repulsion. The unpolarized and polarized structure functions are examined for both ³He and ³H in order to test the usefulness of ³He as a neutron target. It is found that the measurement of the spin structure function of polarized ³H would provide a very clear test of the predicted change in the polarized parton distributions of a bound proton.