Measurement of the Production Cross-Section for $$W + \gamma$$ in the Electron Channel in $$\sqrt{s}$$ = 1.8-TeV $$p\bar{p}$$ Collisions
- Tufts U.
The production cross section times decay branching ratio for W + $$\gamma$$ in the electron decay channel in $$\sqrt{s}$$ = 1.8 TeV $$p\overline{p}$$ collisions has been measured using $$W \to e\gamma$$ data sample obtained from the CDF 1988-89 Tevatron collider run. For photons in the central region ( $$\eta_{\gamma}$$ < 1.1) of the CDF detector with transverse energies $$E^{\gamma}_\tau$$ > 5.0 GeV and lepton-photon angular separation $$\Delta R_\ell\gamma$$ > 0.7, eight electron $$W \gamma$$ candidates were observed. From these events, the production cross section times decay branching ratio for the electron sample was measured to be: $$\sigma$$ · B($$W\gamma)_{exp}$$ = $$17.0^{+13.6}_{-13.4}$$ (stat.+ syst.) pb. The $$W\gamma$$ cross section is sensitive to the anomalous couplings of the W boson. Using the $$W\gamma$$ cross section measurement, the absence of an excess of large $$E_\tau$$ photons accompanying the production of a W boson enables one to obtain direct limits on anomalous $$WW\gamma$$ couplings. The experimental limits on the anomalous couplings was measured to be: -7.2 < $$\Delta \kappa$$, < +7.7 ($$\lambda$$ >. = 0) and -3.5 < $$\lambda$$ < +3.4 ($$\Delta \kappa$$ = 0) at 95% CL. These experimental limits impose contraints on possible internal structure of the W boson with compositeness scale sensitivity $$\Lambda w \geq$$ 1 TeV for saturation of unitarity, corresponding to probing a distance scale of order $$L_{w} \leq$$ 2.0 x $$10^{-4} fm$$. The experimental limits on anomalous $$WW\gamma$$ couplings place bounds on the higher-order electromagnetic moments of the W boson - the magnetic dipole and electric quadrupole moments and the W boson mean-squared charge radius. The experimental results presented in this thesis are in good agreement 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
- OSTI ID:
- 1424418
- Report Number(s):
- FERMILAB-THESIS-1993-17; UMI-94-19334; 383378
- Country of Publication:
- United States
- Language:
- English
Similar Records
Study of the WW{gamma} and WWZ interactions at D0
Double boson production at CDF