XE / $$D_2$$ Cross-Section Ratio from Muon Scattering at 490-GeV/C

Thesis/Dissertation · Mon Jan 01 04:00:00 EST 1990

DOI:https://doi.org/10.2172/1427756· OSTI ID:1427756

Magill, Stephen R. ^[1]

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1. Illinois U., Chicago

The ratio of cross sections for inelastic muon scattering from nucleons in xenon and "free" nucleons (in deuterium) was studied in the region of low $$x_{B_j}$$ (0.001 < $$x_{B_j}$$ < 0.2) for $Q^2$ values of 0.1 (GeV/$c)^2$ < $Q^2$ $$\le$$ 40 (GeV/$c^)2$.Corrections were made for trigger acceptance, scattered muon reconstruction efficiency, the non-isoscalarity of the xenon target, empty target event subtraction, and radiative corrections. The separation of the radiative background from inelastic scattered events was accomplished using 3 independent methods - restricted kinematic cuts, a calorimeter energy cut, and cal· culation of the radiative contributions to the measured cross section using standard quantum electrodynamic theory. These 3 methods yielded results which were consistent well within the statistical errors reported for the analysis.The ratio of cross sections was determined as a function of $$x_{B_j}$$, $Q^2$, and $$\nu$$. The ratio dependence on ZBi and 11 shows shadowing at low $$x_{B_j}$$ and over the entire range of $$\nu$$. These results can not distinguish between the two general types of models used to explain the shadowing phenomenon - vector dominance models (including generalized vector dominance) and parton (including QCD) models. However, the $Q^2$ dependence of the ratio indicates that where shadowing exists in the low $$x_{B_j}$$ region, the $Q^2$ dependence is flat, supporting a parton model (or -QCD) approach to explain the shadowing phenomenon.

• Research Organization: Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
• DOE Contract Number: AC02-07CH11359
• OSTI ID: 1427756
• Report Number(s): FERMILAB-THESIS-1990-17; UMI-91-07641; 305467
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS