[en] The jets of quarks are studied: functions of distrbution and fragmentation, general properties, recursive model, e⁺e^- annihilation and high P(T) reactions

[en] A review is given of the theoretical understanding that has been obtained from experiments at the CERN ISR on correlations in large transverse momentum reactions. (orig.)

[en] This session was devoted to high energy hadronic interactions. Special emphasis was put on the production of jets in soft and hard hadronic collisions

[en] Evidence for hadronic jets has been observed most clearly in e⁺e^- annihilation. The experimental results obtained on particles associated with a high-p(trans) particle in pp collisions at high energies(ISR) are consistent with the jet model. The hadronic jets in e⁺e^- annihilation and in high-p(trans) pp collision seem to have similar properties. The quart-parton model, which relates lN-scattering, e⁺e^-annihilation and possibly high-p(trans) pp scattering, works well for lN scattering and also for e⁺e^- annihilation. For pp scattering the main diffeculty of the model is the experimental absence of the predicted p(trans)^-4 scaling behaviour. (BJ)

[en] The general phenomenon of jet production and their properties are presented. A semi-classical model and a recursive model are studied

[en] Here, we explore the scale-dependence and correlations of jet substructure observables to improve upon existing techniques in the identification of highly Lorentz-boosted objects. Modified observables are designed to remove correlations from existing theoretically well-understood observables, providing practical advantages for experimental measurements and searches for new phenomena. We study such observables in W jet tagging and provide recommendations for observables based on considerations beyond signal and background efficiencies

[en] The data collected in ATLAS at √s = 7TeV in 2010, are being used to perform the measurement of the inclusive jet cross section. The inclusive jet cross section is measured in different rapidity intervals up to very forward regions (|y| < 4.4), with transverse momentum in the interval 0.02.1.5TeV for central rapidities. The systematics of the measurement has been widely investigated, and the impact of the uncertainty on the energy calibration of jets, which is the cause of the dominant uncertainty in the measurement, is discussed.

[en] I discuss a set of observables of large interest for understanding the (soft) hadronisation of partons, in particular the sizable observed polarisations of hyperons and its possible connection to color flow. Further I discuss a set of possible gluon models, in particular the Lund gluon model and its consequences with regard to charm production and possible interpretations difficulties in the calculation of jet cross sections

[en] Evolution of QCD jets beyond the LLA (Leading Logarithm Approximation) is discussed in the framework of the jet calculus. New results for the order αsub(s)sup(2) inclusive gluon decay functions are presented

[en] We study jet angularity measurements for single-inclusive jet production at the LHC. Jet angularities depend on a continuous parameter $a$ allowing for a smooth interpolation between different traditional jet shape observables. We establish a factorization theorem within Soft Collinear Effective Theory (SCET) where we consistently take into account in- and out-of-jet radiation by making use of semi-inclusive jet functions. For comparison, we elaborate on the differences to jet angularities measured on an exclusive jet sample. All the necessary ingredients for the resummation at next-to-leading logarithmic (NLL) accuracy are presented within the effective field theory framework. We expect semi-inclusive jet angularity measurements to be feasible at the LHC and we present theoretical predictions for the relevant kinematic range. In addition, we investigate the potential impact of jet angularities for quark-gluon discrimination.