Determination of sin2 θeff w using jet charge measurements in hadronic Z decays

The electroweak mixing angle is determined with high precision from measurements of the mean difference between forward and backward hemisphere charges in hadronic decays of the Z. A data sample of 2.5 million hadronic Z decays recorded over the period 1990 to 1994 in the ALEPH detector at LEP is used. The mean charge separation between event hemispheres containing the original quark and antiquark is measured for bb̄ and cc̄ events in subsamples selected by their long lifetimes or using fast D*'s. The corresponding average charge separation for light quarks is measured in an inclusive sample from the anticorrelation between charges of opposite hemispheres and agrees with predictions of hadronisation models with a precision of 2%. It is shown that differences between light quark charge separations and the measured average can be determined using hadronisation models, with systematic uncertainties constrained by measurements of inclusive production of kaons, protons and A's. The separations are used to measure the electroweak mixing angle precisely as sin2 θeff w = 0.2322 ± 0.0008(exp. stat.) ±0.0007(exp. syst.) ± 0.0008(sep.). The first two errors are due to purely experimental sources whereas the third stems from uncertainties in the quark charge separations

Towards an understanding of linguistic consultancy : how do linguists approach the task of evaluating sociolinguistic practice in consultancy sessions?

This chapter aims to (1) share insights from our work exploring how applied linguists can help sports coaches critically reflect on their linguistic behaviour, and (2) use this work to reflect on the role and boundaries of the applied linguist as consultant. We present a case study analysis of coach communication in an all-female competitive netball team, which involved consideration of linguistic practice in light of the coach’s goals, values and beliefs about leadership and her role in the construction of positive team environments. We critically reflect on the role and boundaries within which the applied linguist as consultant operates. For applied linguists to be effective consultants, and to hold true to their disciplinary aim of accounting for language use in social context, they need to orient to an expertise-sharing consultancy model, working with those they consult. The potential issues that emerge from such a model are also highlighted

Electroweak parameters of the z0 resonance and the standard model

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