5–12 Jul 2017
Venice, Italy
Europe/Zurich timezone
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Extraction of alpha_s at NNLO and measurement of jet cross sections in Deep-inelastic Scattering at HERA

7 Jul 2017, 09:30
15m
Room Mosaici-1 (Palazzo del Casinò)

Room Mosaici-1

Palazzo del Casinò

Parallel Talk QCD and Hadronic Physics QCD and hadronic physics

Speakers

Daniel Britzger (Deutsches Elektronen-Synchrotron (DE)) Daniel Britzger (Deutsches Elektronen-Synchrotron (DE))

Description

A precision measurement of jet cross sections in neutral current deep-inelastic scattering for photon virtualities $5.5 < Q^2 < 80$ GeV$^2$ and inelasticities $0.2 < y < 0.6$ is presented, using data taken with the H1 detector at HERA, corresponding to an integrated luminosity of 290 pb$^{−1}$. Double-differential inclusive jet, dijet and trijet cross sections are measured simultaneously and are presented as a function of jet transverse momentum observables and as a function of $Q^2$. Jet cross sections normalised to the inclusive neutral current DIS
cross section in the respective $Q^2$-interval are also determined. Previous results of inclusive jet cross sections in the range $150 < Q^2 < 15 000$ GeV$^2$ are extended to low transverse jet momenta $5 < P_T < 7$ GeV. The data are compared to predictions from perturbative QCD in next-to-leading order in the strong coupling, in approximate next-to-next-to-leading order and in full next-to-next-to-leading order. Using also the recently published H1 jet data at high values of $Q^2$, the strong coupling constant $\alpha_s(M_Z)$ is determined in next-to-leading order. [arxiv:1611.03421, accepted by EPJC]
A first determination of the strong coupling αs in next-to-next-to leading order (NNLO) from inclusive jet and dijet production in deep-inelastic scattering at HERA is presented. The strong coupling is determined in a fit of jet data collected by the H1 experiment in the range of momentum transfer 5.5<Q2<15000 GeV2 and jet transverse momenta pT>5 GeV. The running of the strong coupling is probed in a single experiment over one order of magnitude in the remornalisation scale μr. NNLO predictions were obtained using the program NNLOJET, where the corresponding calculations are based on antenna subtraction techniques.

Experimental Collaboration H1

Presentation materials