Nevtrinske mase kot kvantni popravek v skotogenskem modelu

Pipuš, Alenka (author), Bajc, Borut (mentor)

Standardni model ne pojasni nevtrinskih mas, temne snovi in barionske asimetrije v vesolju. Odgovore na ta odprta vprašanja iščemo v fiziki izven Standardnega modela. Naravna razširitev Standardnega modela je dodatek desnoročnih nevtrinov, za katere lahko zapišemo Majoranov masni člen in skupaj z levoročnimi nevtrini še Diracov masni člen. Skotogenski model pojasni majhnost nevtrinskih mas kot kvantni popravek na redu ene zanke in hkrati vsebuje kandidata za temno snov, ki je lahko fermionske ali bozonske narave. V razširjenem skotogenskem modelu dodamo še dva hipotetična delca izven Standardnega modela, ki omogočita radiacijski razpad protona. V skotogenskem modelu je bilo pokazano, da lahko preko leptogeneze generiramo opaženo barionsko simetrijo, medtem ko za raširjeni skotogenski model to možnost le nakažemo. V zadnjem delu naloge pokažemo, da v razširjenem skotogenskem modelu nove interakcije ne podajo novega mehanizma nastanka nevtrinskih mas na redu ene zanke. Obravnavamo razpadne kanale vektorskega kvarka D in desnoročnega nev- trina N . Za razpad $D \to Q + \eta$ izračunamo razliko razpadnih širin med delcem in antidelcem za interferenco med amplitudo drevesnega reda in amplitudo kvantnega popravka. Na koncu nakažemo možnost nastanka barionske in leptonske številske asimetrije v razširjenem skotogenskem modelu

• Language: Slovenian
• Keywords: nevtrinske mase, skotogenski model, kvantni popravek, razširjeni skotogenski model, fizika izven Standardnega modela, leptoge neza
• Work type: Master's thesis/paper
• Organization: FMF - Faculty of Mathematics and Physics
• Year: 2026
• PID: 20.500.12556/RUL-188326
• Publication date in RUL: 20.09.2026

Secondary language

• Language: English
• Title: Neutrino masses as a quantum correction in the scotogenic model

Abstract

The Standard Model does not explain neutrino masses, dark matter and the baryon asymmetry of the Universe. To answer these open questions, we need to look for answers in physics beyond the Standard Model. A natural way to extend the Stan- dard Model is to add right-handed neutrinos, for which we can write a Majorana mass term, and together with the left-handed neutrinos, a Dirac mass term. The scotogenic model explains the smallness of neutrino masses as a quantum correction at one-loop level and at the same time, it contains a dark matter candidate, which can be either bosonic or fermionic. In the extended scotogenic model, two additional hypothetical particles beyond the Standard Model are introduced to enable radia- tive proton decay. In the Scotogenic model, it was shown that the observed baryon asymmetry can be generated through leptogenesis, while in the extended scotogenic model we only explore this possibility. In the last part of the thesis, we show that the additional interactions in the extended scotogenic model do not provide a new mechanism of generating the neu- trino masses at one-loop level. We analyze the decay channels of the vector-like quark D and the right-handed neutrino N . For the decay $D \to Q + \eta$, we calculate the difference between the decay widths of the particle and antiparticle arising from the interference between the tree-level amplitude and the amplitude of the quantum correction. Finally, the possibility of generating baryon and lepton number asym- metries in the extended scotogenic model is explored.

• Keywords: eutrino masses, scotogenic model, quantum correction, physics beyond the Standard model, leptogenesis