Single top quark differential decay rate formulae including detector effects

Abstract

Since the discovery of parity violation in 1957, angular distributions of leptons coming from the weak decay of polarized fermions have been used to probe the structure of the Wqq' vertex. Vector and axial vector couplings reveal themselves in the angular distributions of both light and heavy polarized fermions, but tensor and pseudotensor couplings have a prominent influence on the angular distributions only for fermions heavier than the W boson; i.e. the top quark. The copious t-channel production of polarized single top quarks at the LHC provides an opportunity to study the angular distributions of leptons from polarized top quark decay. In this paper we develop formulae for differential rates intended to be used as a likelihood function in the simultaneous extraction of decay amplitudes, phases, and polarization. The incorporation of detector effects in these formulae is accomplished using a variant of the familiar convolution theorem applying to a decomposition of the differential rates in spherical harmonics.

arXiv comment26 pages, 3 figures

Cited by in corpus (3)

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• Analysis of the $Wtb$ vertex from the measurement of triple-differential angular decay rates of single top quarks produced in the $t$-channel at $\sqrt{s}$ = 8 TeV with the ATLAS detector
• $T$-odd correlations in polarized top quark decays in the sequential decay $t(\uparrow )\to X_b+W^{+}(\to {\ell }^{+}+{\nu }_{\ell })$ and in the quasi three-body decay $t(\uparrow )\to X_b+{\ell }^{+}+{\nu }_{\ell }$