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Miguel A. Benitez

Publications and source records attributed to Miguel A. Benitez.

3 recordsLinked to original sources

A Precise Determination of $α_s$ from the Heavy Jet Mass Distribution

A global fit for $α_s(m_Z)$ is performed on available $e^+e^-$ data for the heavy jet mass distribution. The state-of-the-art theory prediction includes $\mathcal{O}(α_s^3)$ fixed-order results, N$^3$LL$^\prime$ dijet resummation, N$^2$LL Sudakov shoulder resummation, and a first-principles treatment of power corrections in the dijet region. Theoretical correlations are incorporated through a flat random-scan covariance matrix. The global fit results in $0.1148^{+ 0.0015}_{-0.0022}$, compatible with similar determinations from thrust and $C$-parameter. Dijet resummation is essential for a robust fit, as it engenders insensitivity to the fit-range lower cutoff; without resummation the fit-range sensitivity is overwhelming. In addition, we find evidence for a negative power correction in the trijet region if and only if Sudakov shoulder resummation is included.

hep-ph↗

Determining $α_s(m_Z)$ from the Heavy Jet Mass distribution

We present a state-of-the-art analysis on determining the strong coupling constant $α_s(m_Z)$ from available $e^+e^-$ data for the Heavy Jet Mass (HJM) distribution. Dijet resummation is supplemented with additional resummation of shoulder logarithms appearing around the symmetric 3-jet configuration of the HJM spectrum. In addition to $α_s(m_Z)$ we further obtain numerical results for two non-perturbative parameters, $Ω_1^ρ$ and $Θ_1$, encompassing effects from dijet and trijet hadronization effects, respectively.

hep-ph↗

On Determining $α_s(m_Z)$ from Dijets in $e^+e^-$ Thrust

We update a previous N$^3$LL$^\prime$+${\cal O}(α_s^3)$ determination of the strong coupling from a global fit to thrust data by including newly available perturbative ingredients, upgrading the renormalization scales to include a fully canonical scaling region, and implementing the log resummation in a way which ensures the integrated cross section is unaffected by the the leading $1/Q$ hadronization power corrections. Detailed discussions are provided concerning the stability of the results under variations of the fit range and the importance of summing up higher-order logarithmic terms for convergence and stability. We show that high-precision results can be achieved even when carrying out a more conservative fit by restricting the dataset to a region which is more clearly dominated by dijet events. This leads to $α_s(m_Z) = 0.1136 \pm 0.0012$ with $χ^2/{\rm dof}=0.86$, fully compatible with earlier results using a larger fit range. We also demonstrate that a number of additional effects associated to power corrections have a small impact on this fit result, including modifications to the renormalon substraction scheme for dijet power corrections and the inclusion of three-jet power correction models. The fit is also shown to provide very good agreement with data outside the fit range.

hep-ph↗