Wiedner Hauptstr. 8-10
E-Mail: denisp (at) hep.itp.tuwien.ac.at
Tel.: +43 1 58 80 11 36 35
Fax: +43 1 58 80 11 36 99
I am interested in various aspects of Quantum Chromodynamics (QCD):
- Meson Spectroscopy: Quarkonia, Tetraquarks, Glueballs via Effective Field Theories and Holographic QCD
QCD at Finite
Densities: Compact Stars.
What I Do:
I am currently interested in glueballs, bound states of gluons (gauge bosons of QCD). These “states of pure energy” should appear as a result of the strong interaction just as, e.g., protons, neutrons and pions do – the difference being that the latter are basically composed of quarks rather than gluons. The trouble is that glueballs have still not been discovered in experiments and my work is aimed at supplying their observables (masses, decay widths) that can be found in the data. An interesting aspect of the story is that glueballs rarely come alone: they can be mixed with non-glueball, strongly interacting states and only the product of their interference should be observable experimentally. It is not yet quite clear which consequences this has – and my work is aimed at helping resolve this problem as well.
Currently: Research Fellow at Vienna
University of Technology
2012: PhD exam, Institute for Theoretical Physics,
PhD thesis: Quarkonium Phenomenology in Vacuum
2007: Diploma exam in physics, Frankfurt University
Diploma thesis: Pion-Pion Scattering in a Gauged Linear Sigma Model with Chiral U(2)L x U(2)R Symmetry
2002: Graduation at the Comprehensive Grammar
School in Zenica/Bosnia-Herzegovina
Ø 2008: Scholarship, Polytechnical Society Foundation Frankfurt am Main
Ø 2004: Scholarship, Friedrich Ebert Foundation
My PhD thesis in 304 Words
The thesis had
scalar, pseudoscalar, vector and axial-vector mesons
– both nonstrange and strange – as its topic. The
basic premise was simple: a glance at experimental data, e.g., those supplied
by the Particle Data Group (PDG) reveals
that the number of the isosinglet scalar mesons is
larger than what would be expected from an antiquark-quark
(quarkonium) structure. Hence not all of them can be quarkonia and the main topic of my thesis was the search
for those isosinglet scalars that are consistent with the quarkonium structure.
However, it is not as
simple as considering just scalars: experiments also tell us that scalars
interact with other meson classes: pseudoscalars,
vectors and axial-vectors. Hence I used one model for all of them: an Extended
Linear Sigma Model (eLSM) with three quark flavours (eLSM) to fit some and predict other meson masses and decay
The result was that scalar antiquark-quark states are heavier than perhaps naively expected: they are located above 1 GeV in the meson spectrum. Additionally, similar statements can be made about other mesons the nature of which is under discussion: I found a1(1260) to represent a quarkonium as well.
So why is this important? For at least two reasons: firstly, we obtain a closer sense about classification of the large number of meson states. (Those that are not composed of quarks could be glueballs, see above what I do now.) Secondly, signatures of the so-called quark-gluon plasma, a state of matter that existed shortly after the Big Bang, rely for example on the degeneration of chiral partners – mesons of the same structure but with some varying quantum numbers. The identification of chiral partners is thus extremely important and it can only be done if meson structures are known. Hence the need to gain insight into their inner dealings, such as done in my thesis.