Final state interactions in single- and multi-particle inclusive cross sections for hadronic collisions

We study the role of low momentum transfer (soft) interactions between high-transverse momentum heavy particles and beam remnants (spectators) in hadronic collisions. Such final-state interactions are power suppressed for single-particle inclusive cross sections whenever that particle is accompanied by a recoiling high-p_T partner whose momentum is not fixed. An example is the single-top inclusive cross section in top pair production. Final-state soft interactions in multi-particle inclusive cross sections, including transverse momentum distributions, however, produce leading power corrections in the absence of hard recoiling radiation. Nonperturbative corrections due to scattering from spectators are generically suppressed by powers of \Lambda/p'_T, where \Lambda is a hadronic scale, and p'_T is the largest transverse momentum of radiation recoiling against the particles whose momenta are observed.Comment: 18 pages, 6 figure

Communications

Various communications concerning previous topics covered in Performance Practice Revie

The Photodetection Process under the Conditions of an Imperfect Measurement Device

The process of cavity mode quantum state photodetection subject to a nonideal measurement device is under consideration. A set of nonorthogonal probabilistic operator valued measures (POVMs) describing the photodetection process is suggested. The superoperators of conditional system evolution and their Kraus representations are obtained. Developed formalism is used to the quantum state reconstruction problem. We recalculate the probabilities of hypotheses about the initial state of cavity quantum mode in the case of unknown superposition of vacuum and single photon states.Comment: 2 figures, 8 pages, reported at XI International Workshop on Quantum Optics, Volgograd, Russi

The Short and Long Term Prospects for Activity in the UK Continental Shelf : the 2011 Perspective

Preprin