26-30 March 2012
University of Bonn
Europe/Berlin timezone

Diffraction and rapidity gap measurements with ATLAS

29 Mar 2012, 09:40
Lecture Hall, Institute for Applied Physics (University of Bonn)

Lecture Hall, Institute for Applied Physics

University of Bonn

Diffraction and vector mesons Diffraction and vector mesons


Pavel Ruzicka (Acad. of Sciences of the Czech Rep. (CZ))


Transverse energy distributions and regions of low activity in proton-proton scattering events are sensitive to soft physics, low x and diffractive processes, and have been measured in inclusive "minimum bias" scatters as well as in dijet events at sqrt(s) = 7 TeV. In the inclusive analysis, cross sections are measured differentially in terms of Delta eta F, the larger of the pseudorapidity regions extending to the limits of the ATLAS sensitivity, in which no final state particles are produced above a transverse momentum threshold p_T Cut. The measurements span the region 0 < Delta eta F < 8 for 200 < p_T Cut < 800 MeV. The data are used to constrain the value of the pomeron intercept appropriate to triple Regge models of soft diffraction, and the cross section integrated over all gap sizes is compared with other LHC inelastic cross section measurements. The dijet measurements study jet activity in the rapidity interval bounded by a dijet system, as well as in the forward region. Differential distributions are compared to various QCD calculations including different approximations for gluon radiation.

Primary author

Prof. Mark Oreglia (University of Chicago (US))

Presentation Materials