Initial state radiation in the Herwig 7 angular-ordered parton shower

We study the simulation of initial-state radiation in angular-ordered parton showers in order to investigate how different interpretations of the ordering variable affect the logarithmic accuracy of such showers. This also enables us to implement a recoil scheme which is consistent between final-state and initial-state radiation. We present optimal values of the strong coupling and intrinsic transverse momentum to be used in each version of the parton shower, tuned using Z0-boson production at the LHC at 7 TeV. With these tuned showers, we perform a phenomenological study of the Drell-Yan process at several centre-of-mass energies.

KT MEASUREMENT OF PARTONS FROM DI-HADRON CORRELATION AND A COMPARATIVE STUDY WITH JET RECONSTRUCTION METHOD USING PYTHIA

The hard scattering processes appear as back to back jets in pp collisions. The effective transverse momentum of the two hard scattered partons (kt) arises due to the intrinsic transverse momentum of the partons and its broadening. Azimuthal correlations of the neutral clusters (mostly from π0) with transverse energy Et=6.5-18.5 GeV as trigger particles and the charged tracks as associated particles have been measured by the STAR experiment in pp and dAu collisions at [Formula: see text]. Using the di-hadron correlation technique the effect of the cold nuclear matter on [Formula: see text] is discussed. A simulation study from PYTHIA using simple di-jet like clustering is also discussed in context of results of [Formula: see text] from di-hadron correlations and di-jets.

Large pT Hadron Spectra in pp, pA and AA Collisions

Large pT particle spectra in p+p, p+A and A+B collisions at different energies are calculated in a QCD parton model. Intrinsic transverse momentum, its broadening due to initial multiple parton scattering are included. These calculations are meant to estimate the normal nuclear effects (parton shadowing, pT broadening or Cronin effect) in high pT hadron spectra in heavy-ion collisions. Comparisons of these calculations with experimental data will help to determine the effect of jet quenching.

The A-Dependence of Open Charm and Bottom Production

We study inclusive heavy quark and exclusive heavy quark pair production in pp and pA interactions. Intrinsic transverse momentum is introduced in pp interactions. Nuclear effects are introduced in pA interactions, including kT broadening and nuclear shadowing. The nuclear dependence is studied over a range of energies, both in fixed target and collider setups.