We report first results on the calculation of NNLO corrections to event shape distributions in electron-positron annhilation. The corrections are sizeable for all variables, however their magnitude is substantially different for different observables. We observe that inclusion of the NNLO corrections yields a considerably better agreement between theory and experimental data both in shape and normalisation of the event shape distributions.

'Precise QCD predictions for the production of a Z boson in association with a hadronic jet.', Physical review letters., 117 (2). 022001.Further information on publisher's website:http://dx.doi.org/10.1103/PhysRevLett.117.022001Publisher's copyright statement:Reprinted with permission from the American Physical Society: Physical Review Letters 117, 022001 c (2016) by the American Physical Society. Readers may view, browse, and/or download material for temporary copying purposes only, provided these uses are for noncommercial personal purposes. Except as provided by law, this material may not be further reproduced, distributed, transmitted, modied, adapted, performed, displayed, published, or sold in whole or part, without prior written permission from the American Physical Society.Additional information: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details.

The production of two jets is the simplest exclusive quantum chromodynamics process in electronpositron annihilation. Using this process, we examine the structure of next-to-next-to-leading order (NNLO) corrections to jet production observables. We derive a subtraction formalism including double real radiation at tree level and single real radiation at one loop. For two-jet production, these subtraction terms coincide with the full matrix elements, thus highlighting the phase space structure of the subtraction procedure. We then analytically compute the infrared singularities arising from each partonic channel. For the purely virtual (two-parton) NNLO corrections, these take the well known form predicted by Catani's infrared factorization formula. We demonstrate that individual terms in the infrared factorization formula can be identified with infrared singular terms from three-and fourparton final states, leaving only single poles and a contribution from the one-loop soft gluon current, which subsequently cancels between the three-and four-parton final states. Summing over all different final states, we observe an explicit cancellation of all infrared poles and recover the known two-loop correction to the hadronic R-ratio.N in includes all QCD-independent factors, m denotes the sum over all configurations with m partons, dΦ m is the phase space for m partons, S m is a symmetry factor for identical partons in the final state and finally |M m | is the tree level m-parton matrix element. The jet function F (m) J defines the procedure for building J-jets out of m partons. The main property of F (m) J is that the jet observable defined above is collinear and infrared safe as explained in [18]. In general F (m) J