# 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.

### Members of the Research Group

#### Professors

Photo | Degree | Firstname | Lastname | Room | Phone | |
---|---|---|---|---|---|---|

Prof. Dr. | Nora | Brambilla | Physik I: 3217 | +49 89 289-12353 | ||

#### Staff

Photo | Degree | Firstname | Lastname | Room | Phone | |
---|---|---|---|---|---|---|

Dipl.-Phys. | Matthias | Berwein | Physik I: 3312 | +49 89 289-12359 | ||

M.Sc. | Sungmin | Hwang | Physik I: 3211 | +49 89 289-12390 | ||

Dr. | Javad | Komijani | – | – | ||

Chris | Quigg | – | +49 89 289-10682 | |||

Dr. | Jorge | Segovia | – | +49-015255478895 | ||

M.Sc. | Vladyslav | Shtabovenko | Physik I: 3316 | +49 89 289-14330 | ||

B.Sc. | Susanne | Strohmeier | – | – | ||

Dr. | Jaume | Tarrus Castella | Physik I: 3213 | +49 89 289-12337 | ||

Dr. | Johannes | Weber | Physik I: 3302 | +49 176 614 02468 | ||

### Teaching

#### Course with Participations of Group Members

Titel und Modulzuordnung | |||
---|---|---|---|

Art | SWS | Dozent(en) | Termine |

Quantum Mechanics 2
Zuordnung zu Modulen: |
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VU | 6 | Brambilla, N. |
Mittwoch, 12:00–14:00 Freitag, 10:00–12:00 sowie einzelne oder verschobene Termine sowie Termine in Gruppen |

Introduction to the State of the Art in Effective Field Theories in Particle and Nuclear Physics
Zuordnung zu Modulen: |
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SE | 2 | Brambilla, N. | |

Seminar on effective field theories
Zuordnung zu Modulen: |
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SE | 4 | Brambilla, N. Vairo, A. |
Mittwoch, 15:00–17:00 Freitag, 14:00–16:00 |

Seminar zur Physik der starken Wechselwirkung Zuordnung zu Modulen: |
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SE | 2 | Brambilla, N. Fabbietti, L. Kaiser, N. Paul, S. |
Montag, 14:00–16:00 |

#### 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