Measurement of $$\sigma\cdot$$Br($$W + \gamma$$) and $$\sigma\cdot$$BR($$Z + \gamma$$) and Search for Anomalous $$W$$ ($$\gamma$$) and $$Z$$ ($$\gamma$$) Couplings at $$\sqrt{s}$$ = 1.8-TeV
- Univ. of Illinois, Urbana-Champaign, IL (United States)
Measurements of the production cross section times branching ratio for W + γ and Z + γ processes, where the W decays into a muon and neutrino and the Z decays into a muon pair, have been made from the analysis of 18.6±0.7 pb-1 of high-PT muon data from proton-antiproton (p$$\bar{p}$$) collisions. The data were collected with the Collider Detector at Fermilab (CDF) during the 1992-93 run. In a search for central photons (|η| < 1.1) with transverse energy above 7 GeV and angular separation from the muon by at least ΔR = 0. 7, where ΔR = √(Δ Φ2+ Δη2) , we find 7 W γ and 4 Zγ candidates. This translates into cross section times branching ratios of 9.0 ± 6.4 pb for the Wγ process and 6.6 ± 3.4 pb for the Zγ process. Separate measurements were made for photon ET values above 11 Ge V and 15 Ge V. The cross section times branching ratio results were used to calculate a series of cross section ratios. An analysis designed to search for anomalous couplings between the gauge bosons was also carried out using these results. Assuming only one anomalous coupling to be non-zero at a time, the 95% CL limits on W γ anomalous couplings are, -3.7 < Δ κ< 3.7, -1.2 < λ< 1.2, -3.8 < $$\tilde{κ}$$, < 3.8 and -1.2 < $$\tilde{λ}$$ < 1.2. For ZZγ anomalous couplings the experimental limits are measured to be, at the 95% CL, -4.6 < h$$Z\atop{30}$$ (h$$Z\atop{10}$$ ) < 4.6 and -1.1 < h$$Z\atop{40}$$ (h$$Z\atop{20}$$) < 1.1. For Zγγ anomalous couplings the experimental limits are measured to be, at the 95% CL, -4.9 < h$$γ\atop{30}$$ ($$γ\atop{10}$$) < 4.9 and -1.2 < $$γ\atop{40}$$ ( $$γ\atop{20}$$ ) < 1.2. Limits are placed on electromagnetic multi pole moments for both the W and Z bosons using the measured limits of the anomalous couplings, and are presented in this thesis. All of the measurements presented in this thesis are consistent with Standard Model expectations.
- Research Organization:
- Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), High Energy Physics (HEP)
- DOE Contract Number:
- AC02-07CH11359; FG02-91ER40677
- OSTI ID:
- 1372380
- Report Number(s):
- FERMILAB-THESIS-1994-20; UMI-95-22185; 385906
- Country of Publication:
- United States
- Language:
- English
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