List of previous students

Nicola Orlando
Faten Hariri
Emma Kuwertz
Spyridon Argyropoulo
Sabrina Sacerdoti
Simone Amoroso
Jesper Roy Christiansen
Nathan Hartland
Christian Roehr
Benjamin Watt
Philip Ilten
Nishita Desai
Sercan Sen
Miroslav Myska
Sudha Ahuja
Holger Schulz
Avi Gershan
Aleksander Kusina
Magdalena Slawinska
Flavia Dias
Kenneth Wraight
Irais Bautista Guzman
Sparsh Navin
Paolo Francavilla
Riccardo Di Sipio
Seyi Latunde-Dada
Devdatta Majumder
Martijn Gosselink
Christopher Bignamini
Marek Schönherr
Michal Deak
Noam Hod
Florian Bechtel
Jonathan Ferland
Manuel Bähr
Alexander Flossdorf
Piergiulio Lenzi

Michal Deak is a PhD student from DESY, Hamburg, on a four-month MCnet studentship at CERN.

With the appearence of heavy quarks in the hard scattering process a new scale - the mass of the heavy quark, appears. Logarithms of the ratio of the hard scale and heavy quark mass might contribute to the cross section. These logarithms, being large, have to be resummed. In the context of a Monte Carlo generator this can be achieved by taking the mass effects into account in the parton shower algorithm.

At present in the Monte Carlo Herwig++ the mass of the heavy quark is taken into account only in the final state parton showers. My project is investigate the role of mass effects in the initial state parton showers in the HERWIG and Herwig++ Monte Carlo programs and try to implement some of them into Herwig++. The project includes mainly learning to use Monte Carlo generators Herwig and Herwig++ and calculation of splitting functions for processes with massive particles involved in the splitting process for initial state parton splittings.

If one looks on b jets (jets containing a b quark) associated with Z boson production (Drell-Yan process via inihilation of b bbar pair) one observes (figure: transverse momentum of the b-jet on the y-axis and pseudo-rapidity on the x-axis) that the region of low transversal momenta is not filled and that jets are accumulated in a small transverse momentum region close to some threshold. Inclusion of mass effects should remove this unphysical effect.