# 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

#### Professor

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

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

#### Office

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

Susanne Antoinette | Tillich | PH: 3205 | +49 89 289-12358 |

#### Scientists

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

Dr. | Hee Sok | Chung | – | – | ||

Ph.D. | Evan | Johnson | – | – | ||

Ph.D. | Wai Kin | Lai | – | – | ||

Dr. | Viljami | Leino | – | – | ||

M.Sc. | Gramos | Qerimi | – | – | ||

Yifan | Song | – | +49 177 4013157 | |||

M.Sc. | Sebastian | Steinbeißer | – | – | ||

M.Sc. | Peter | Vander Griend | – | – | ||

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

Dr. | Yan | Zhu | – | 12329 |

#### Other Staff

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

Dr. | Rafael | Delgado López | – | +34 682 741078 | ||

M.Sc. | Sungmin | Hwang | PH: 1141 | – | ||

Dr. | Javad | Komijani | – | – |

### Teaching

#### Course with Participations of Group Members

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

Art | SWS | Dozent(en) | Termine |

Theoretical Particle Physics
Zuordnung zu Modulen: |
|||

VO | 4 | Brambilla, N. |
Di, 12:00–14:00, PH 3344 Do, 08:30–10:00, PH 3344 |

Tutorial to Theoretical Particle Physics
Zuordnung zu Modulen: |
|||

UE | 2 |
Lai, W.
Qerimi, G.
Steinbeißer, S.
Vander Griend, P.
Leitung/Koordination: Brambilla, N. |
Termine in Gruppen |

Introduction to the State of the Art in Effective Field Theories in Particle and Nuclear Physics
Zuordnung zu Modulen: |
|||

SE | 2 | Brambilla, N. | |

Seminar on effective field theories
Zuordnung zu Modulen: |
|||

SE | 4 | Brambilla, N. Vairo, A. |
Mi, 14:00–16:00, PH 1121 Fr, 12:00–14:00, PH 1121 |

#### Offers for Theses in the Group

- Dark Matter bound states
Unlike normal matter, dark matter does not interact with the electromagnetic force.

This means it does not absorb, reflect or emit light, making it extremely hard to spot. In

fact, researchers have been able to infer the existence of dark matter

only from the gravitational effect it seems to have on visible

matter. Dark matter seems to outweigh visible matter roughly six to

one, making up about 27% of the universe, but it cannot be explained

inside the Standard model of particle physics.

A lot of contemporary research goes into the search and characterization

of dark matter candidates. In such framework it is very important to

be able to account for bound states interactions that can modify

dark matter production and annihilation cross sections for some

order of magnitudes.

Scope of the thesis is to analyze some simple models for nonrelativistic

dark matter bound state effects using nonrelativistic effective field theories

and solving appropriate Schroedinger equations.*suitable as*- Bachelor’s Thesis Physics

*Supervisor:*Nora Brambilla- Dense 2 color QCD
The QCD phase state diagram is object of study both in theory and in

experiments. A particular interesting phase is the one of high chemical potential.

Scope of this thesis is to study a recent paper on this subject in which

a version of QCD with two colors and two flavors of fermions has been studied on the

lattice as a function of the chemical potential mu and the temperature T.

In particular it is found that the quarkyonic region, where the behaviour of the quark number density and the

diquark condensate are described by a Fermi sphere of almost free quarks distorted by a BCS

gap, extends to larger chemical potentials with decreasing lattice spacing or quark mass. In both

cases, the quark number density also approaches its non-interacting value. The pressure at low

temperature is found to approach the Stefan–Boltzmann limit from below.*suitable as*- Bachelor’s Thesis Physics

*Supervisor:*Nora Brambilla- Numerical solution of the Langevin equation
Heavy quarkonia, namely bound states of a heavy quark and antiquark,

turn out to be useful systems to probe the Quark Gluon Plasma (QGP)

the new state of matter originated in heavy ion collision at the LHC

at CERN and at RHIC at BNL. In particular the hot state of matter can

induce thermal modifications to the quarkonium

states. Experimentally we can see such effects either in the

quarkonium suppression or in changes in the bound state properties

(masses and widths). From a theoretical point of view, effective field

theories give us the possibility to study in detail what happens to

heavy quarkonia in this extremely hot state of matter. The goal of

this thesis is to obtain efficient numerical solutions to some

Langevin equations for the quarkonium density obtained from the

corresponding field theoretical master equation in the classical limit.*suitable as*- Bachelor’s Thesis Physics

*Supervisor:*Nora Brambilla- X, Y, Z exotic states
X, Y, Z states are exotics states observed in the heavy quarkonium

sector at several high energy accelerator experiments (Belle in Japan,

BES in China and experiments at the Large Hadron Collider at

CERN). They are formed by a heavy quark, a heavy antiquark and some

other component (gluonic-hybrids or light-quarks-tetraquarks) that

make them non-standard. The properties of these states are directly

related to the nonperturbative nature of low energy QCD and to the

confinement mechanism of strong interactions. Lattice calculations of

the hybrid and tetraquark static energies are available. The scope of

the thesis is to use these lattice curves together with elementary

notions of nonrelativistic effective field theories to obtain

interaction potentials and solve numerically appropriate Schrödinger

equations to obtain information on the masses and transitions of these

exotic states.*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