Theoretical Particle and Nuclear Physics

Prof. Nora Brambilla

Research Field

Our research is focused on Effective Field Theories (EFTs) and Renormalization Techniques with applications in Particle Physics and Hadronic/Nuclear Physics. Effective quantum field theories are the state-of-the-art tools for analyzing physical systems that contain many different energy or momentum scales. Such systems are the rule, rather than the exception, from the high-energy domain of Particle Physics to the low-energy domain of Nuclear Physics.

Specifically we construct and apply new effective field theories to deal with processes of strong interactions and QCD, Standard Model and beyond the Standard Model physics. At T30f we study non-relativistic effective field theories with applications to heavy-quark processes and quarkonium physics at accelerator experiments (BELLE, BESIII, LHC and PANDA experiments); EFTs for strong interactions at finite temperature and density with applications to processes taking place at heavy-ion experiments at RHIC and LHC, as well as in cosmological environments. Furthermore we work on high-order perturbative calculations in QCD with applications to precision determination of certain Standard Model parameters (quark masses, strong coupling constant) as well as non-perturbative and computational methods in field theory with application to non-perturbative QCD and the confinement mechanism.

Address/Contact

James-Franck-Str. 1/I
85748 Garching b. München

Members of the Research Group

Professors

Staff

Teaching

Course with Participations of Group Members

Offers for Theses in the Group

Quarkonium dissociation at the Large Hadron Collider

Ongoing experiments at the Large Hadron Collider (LHC) at CERN explore
heavy ion collisions in an unprecedented energy window, with lead nuclei
colliding now at a centre-of-mass energy of 2.76 TeV per colliding nucleon
pair. The aim of these experimental investigations is the formation of the
Quark Gluon Plasma (QGP), a new state of matter that should originate when
nuclear matter undergoes a phase transition from its normal hadronic state
to a deconfined partonic phase. This transition is predicted by QCD, the
theory of strong interactions, at a temperature of about 170 MeV. Such
studies have important cosmological and astrophysical implications, given
that we believe that the QGP was existing in the early universe, filling
all space a few microseconds after the Big-Bang.
Heavy quarkonium dissociation is one of the phenomena used to obtain
information about the quark-gluon plasma formation in heavy-ion
collisions. Recent theory results based on effective field theories gives
a description of this phenomenon inside a Schrödinger equation with a
complex potential. The aim of this thesis is to study the correct way of
defining the eigenfunctions and eigenvalues for this problem and write a
computer program able to find them numerically at different temperatures.

suitable as
  • Bachelor’s Thesis Physics
Supervisor: Nora Brambilla
Van der Waals interactions from QED

The electromagnetic interaction between two neutral systems is the
so-called Van der Waals force. Van der Waals interactions are the result
of the interaction between instantaneous dipole moments in the atoms. Two
different regimes have been known for a long time. The short range regime
appears when the momentum transfer between the two neutral atoms is larger
than the excitation energy of the instantaneous dipole. This case is known
as the London force, who was the first to develop it in the 1930. The
London force is characterized by a dependence of R^6, where R is the
distance between the neutral atoms. The long range regime appears in the
opposite conditions, that is, when the momentum transfer between the atoms
is much smaller than the excitation energy of the instantaneous dipole.
These is usually referred as the Casimir-Polder force, who developed it in
the 1948. The Casimir-Polder force depends on the distance like R^7.

An unified description of the different regimes of Van der Waals forces
stemming from first principles can be obtained by employing effective
field theory techniques. The basic idea of effective field theories is
that the dynamics at low-energies do not depend on the high energy
dynamics. Furthermore the effective field theory description allows for a
theoretical description of the polarization factors previously
unavailable. The polarizations are given in terms of a series of the
expected values of the position and spin between the atomic wave functions
of initial state and the instantaneous exited states over all the exited
states. The aim of this thesis is to compute the instantaneous
polarizations of the hydrogen atom and to study the variation for initial
states with different angular momentum as well as to determine if there is
a dominant contribution corresponding to a determinate excited state.
Applications of these findings ranging from strong interaction to dark
matter will be discussed.

suitable as
  • Bachelor’s Thesis Physics
Supervisor: Nora Brambilla

Current and Finished Theses in the Group

Aspects of Van der Waals Interactions
Abschlussarbeit im Bachelorstudiengang Physik
Themensteller(in): Nora Brambilla

Nuclei, Particles, Astrophysics

A journey of discovery to understanding our world at the subatomic scale, from the nuclei inside atoms down to the most elementary building blocks of matter. Are you ready for the adventure?