Measurement of the production cross section for W + γ in the electron channel in √s = 1.8 TeV $$\bar{p}$$p collisions

Thesis/Dissertation · Mon Nov 01 00:00:00 EST 1993

DOI:https://doi.org/10.2172/10133106· OSTI ID:10133106

Benjamin, Douglas P. ^[1]

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1. Tufts Univ., Medford, MA (United States)

The production cross section times decay branching ratio for W+ γ in the electron decay channel in √s = 1.8 TeV $$\bar{p}$$-p collisions has been measured using W → eγ data sample obtained from the CDF 1988--1989 Tevatron collider run. For photons in the central region ($$\bar{η}$$_$$\bar{γ}$$ < 1.1) of the CDF detector with transverse energies E$$T\atop{γ}$$ 5.0 GeV and lepton-photon angular separation ΔR_ℓγ > 0.7, eight electron W_γ candidates were observed. From these events, the production cross section times decay branching ratio for the electron sample was measured to be a σ • B(W_γ)_exp = 17.0$$+13.6\atop{-13.4}$$(stat. + syst.)pb. The W_γ cross section is sensitive to the anomalous couplings of the W boson. Using the W_γ cross section measurement, the absence of an excess of large E_T photons accompanying the production of a W boson enables one to obtain direct limits on anomalous WW_γ couplings. The experimental limits on the anomalous couplings was measured to be -7.2 < Δκ < +7.7 (λ = 0) and -3.5 < λ < +3.4 (Δκ = 0) at 95% CL. These experimental limits impose contraints on possible internal structure of the W boson with compositeness scale sensitivity Λ_W ≥ 1 TeV for saturation of unitarity, corresponding to probing a distance scale of order L_W ≤ 2.0 x 10^-4 fm. The experimental limits on anomalous WW_γ 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: Tufts Univ., Medford, MA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: FG02-92ER40702
• OSTI ID: 10133106
• Report Number(s): DOE/ER/40702-6; ON: DE94008186; BR: 35KA02000/KA0101000; TRN: 94:007415
• Resource Relation: Other Information: TH: Thesis (Ph.D.); PBD: Nov 1993
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
PROTON-ANTIPROTON INTERACTIONS
CROSS SECTIONS
W PLUS BOSONS
COUPLING CONSTANTS
W MINUS BOSONS
PHOTONS
PARTICLE PRODUCTION
TEV RANGE
BRANCHING RATIO
WEINBERG-SALAM GAUGE MODEL
SHOWER COUNTERS
662340
662440
HADRON INTERACTIONS
PROPERTIES OF OTHER PARTICLES INCLUDING HYPOTHETICAL PARTICLES