I am investigating electroweak bosons W and Z. The role of these particles in development of particle physics is crucial. Contemporary theory of electroweak interaction – prediction of Higgs boson including – was created as a consequence of an effort to include these particles using quantum field theory description. Seven scientists were awarded the Nobel prize for the discoveries closely related to the bosons W and Z.
Together with the photon, W and Z are mediators of the electroweak interaction in standard model – leading contemporary theory of particle physics. According to this theory, properties of W and Z are closely related. They were predicted in the sixties in the last century and discovered in 1983 at the collider SPS at CERN near Geneva. They have spin 1 and their mass is 86 and 98 multiple of proton mass for the W and Z, respectively. Their time of life is 10−25 s. Only products of their decay can be detected experimentally. Usually they are detected using lepton decay channels, but the dominant decay is into the pair quark-antiquark. This channel is usually not utilized at hadron colliders due to the large multijet background.
Physics potential of the investigation of W and Z bosons at hadron clolliders is gigantic. It is possible to test validity of standard model, to measure standard model parameters or to investigate structure of the proton. Production of W and Z constitutes relevant background for many other physics processes. Moreover, W and Z appear in decay chain of objects of the highest importance, either already discovered (Higgs boson, top quark) or still searched for (supersymmetric particles, exotic particles). Publications primarily dealing with W and Z represent 12% of all ATLAS publications (to be compared with 14% of publications concerned with Higgs boson).
During the period 2003 – 2008 I was investigating the potential of ATLAS to measure double differential cross section of Z bozon as a function of transverse momentum and rapidity. This process provides test of QCD (theory of strong interaction). I contributed to the ATLAS publication summarising expected performance and physics potential of the experiment before data taking period.
In the period until the end of Run 1 (2006 – 2013) ended by the discovery of Higgs boson I was working in the position of MC Production manager of Standard Model group of the ATLAS Collaboration. I coordinated the creation of samples of
simulated interactions for the whole collaboration. These samples provide model image of real physics processes. They are necessary for the interpretation of measured data. Currently I am dealing with the extraction of the cross section of W produced in proton-proton collisions. I also investigate possibilities and potential physics outcome of W detection in dominant decay channels.