Elektromagnetske funkcije strukture hadrona u perturbativnom QCD-u

master's thesis

• Title (english): Electromagnetic form factors of hadrons in perturbative QCD
• Author: Lovre Pavičić
• Mentor: Goran Duplančić (mentor)
• Mentor: Krešimir Kumerički (komentor)
• Committee member: Krešimir Kumerički (predsjednik povjerenstva)
• Committee member: Goran Duplančić (član povjerenstva)
• Committee member: Ivica Friščić (član povjerenstva)
• Committee member: Sanjin Benić (član povjerenstva)
• Committee member: Nikola Poljak (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Physics); Zagreb
• Defense date and country: 2022-09-09, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract

Elektromagnetske funkcije strukture hadrona su funkcije koje opisuju unutarnju raspodjelu naboja i magnetizacije unutar hadrona. Po kvantnoj kromodinamici hadroni su vezana stanja kvarkova i gluona te im je kao takvima za praktične potrebe nemoguće egzaktno teorijski izračunati funkcije strukture. Međutim, pri sudarima s visokim prijenosima impulsa funkcije strukture je moguće napisati u faktoriziranom obliku. Drugim riječima moguće je odvojiti neperturbativnu dinamiku vezanog stanja i dinamiku samog sudara koja je perturbativno izračunljiva. U ovom diplomskom radu će se promatrati ekskluzivni procesi na visokim energijama u kojima sudjeluju pioni ili nukleoni i cilj je u tim procesima izračunati njihove funkcije strukture. Prvi korak je da se na jedan takav proces primjeni faktorizacija i tako se odvoji neperturbativni dio, koji je sadržan u distribucijskim amplitudama, od perturbativnog. Perturbativni dio biti će određen do vodećeg reda, a rezultati za distribucijske amplitude biti će preuzeti iz literature s obzirom da su distribucijske amplitude neovisne o procesu. Na samom kraju će dobiveni rezultati biti uspoređeni s eksperimentalnima.

Abstract (english)

Electromagnetic form factors are the functions that describe internal distributions of charge and magnetization in hadrons. Within Quantum Chromodynamics the hadrons are bound states of quarks and gluons, and as such, their form factors are practically impossible to be theoretically determined. However, in processes with large momentum transfers it is possible to apply factorization, i.e. it is possible to separate nonperturbative dynamics of a bound state from perturbative ”hard-scattering” amplitude. The goal of this thesis is to calculate form factors of pions and nucleons by analysing large-momentum-transfer exclusive processes in perturbative Quantum Chromodynamics. First step will be using the valence quark approximation and applying factorization on such processes. Non-perturbative dynamics will be contained in distribution amplitudes and results for those will be taken from literature (since they are process independent) while perturbative part will be calculated up to a leading order. Those two will be combined to calculate form factors. At the end, calculated results will be compared to some experimental values.

• Keywords: perturbativni QCD; funkcije strukture; faktorizacija; distribucijske amplitude
• Keywords (english): perturbative QCD; form factors; factorization; distribution amplitudes
• Language: croatian
• URN:NBN: urn:nbn:hr:217:273340
• Study programme: Title: Physics; specializations in: Research; Course: Research; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: magistar/magistra fizike (magistar/magistra fizike)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2022-10-18 09:02:13