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Abstrak :
Telah dihitung polarisasi, penampang lintang diferensial dan jalan bebas rata-rata pada interaksi neutrino-gas elektron dengan mempertimbangkan faktor bentuk elektromagnetik neutrino, untuk temperahu' berhingga. Faktor- faktor yang dipertimbangkan pada perhitungan adalah retardasi, detail balans dan Pauli bloking serta anti partikel. Efek banyak benda masuk dalam perhitungan polarisasi melalui pendekatan korelasi fase random ( random phase approximation ) dan massa foton efktif. Hasil yang didapat digunakan untuk mempelajari interaksi neutrino dengan materi pada atmosfir Supernova. Hasil penelitian ini menunjukkan seberapa besar pengaruh faktor-faktor temperatur, kerapatan elektron, momen dipol neutrino, jari-jari muatan neutrino, korelasi random phase approximation, massa foton efektif dan koreksi relativitas umum pada jalan bebas rata-rata neutrino pada atmosfir supernova. ......The polarizations, differential cross section and mean free path of neutrino-electron gas interaction have been calculated by taking into account the neutrino electromagnetic form factor, for finite temperature. 'The retarded, detailed balance, Pauli blocking and anti-particle factors have been also taken into account in the calculations. Many~body effects enter into polarizations calculations through random phase approximation correlation and photon effective mass. The results are used to study the interaction of neutrino with matter in supernova atmosphere. It has also shown how large the influence of temperature, electron density, neutrino moment dipole, neutrino charge radius, random phase approximation correlation, photon effective mass and general relativity correction in mean free path at supernova atmosphere.

Abstrak :
The differential cross-section of neutrino interaction with dense and warm electron gasses has been calculated by taking into account the neutrino electromagnetic form factors. The significant effect of electromagnetic properties of neutrino can be found if the neutrino dipole moment, μν, is ≥5.10-9 μB and neutrino charge radius, Rv, is ≥5.10-6MeV-1. The importance of the retarded correction, detailed balance and Pauli blocking factors is shown and analyzed. Many-body effects on the target matter which are included via random phase approximation (RPA) correlation as well as photon effective mass are also investigated.

Abstrak :
Hamburan neutrino dengan materi bintang quark melalui interaksi lemah arus ne- tral telah dipelajari. Untuk menjelaskan keadaan materi quark, digunakan model bag MIT. Struktur bintang quark dapat dipelajari dengan memasukkan persamaan keadaan bintang quark kedalam persamaan TOV. Dalam tulisan ini kami mempela- jari penampang lintang differensial dan lintasan bebas rata-rata neutrino. Perhitun- gan dilakukan menggunakan dua metode; Pertama dengan memperhatikan hambu- ran N-body sebagai N kali hamburan dua partikel, Kedua dengan memperlakukan efek banyak benda dengan baik dalam hamburan N-body. Kedua pendekatan dipela- jari dan dibandingkan pada kasus temperatur nol. Untuk pendekatan pertama, interaksi didominasi oleh quark down, sedangkan untuk pendekatan kedua quark down dan quark strange memberikan kontribusi yang sama. Lintasan bebas rata- rata neutrino menurun dengan meningkatnya kerapatan, temperatur dan energi awal neutrino. Untuk kasus temperatur berhingga, terdapat beberapa faktor yang perlu diperhatikan, seperti; faktor retardasi, Pauli blocking dan detailed balancing. Pauli blocking dan detailed balancing secara signifikan mengurangi nilai lintasan bebas rata-rata neutrino. Sedangkan faktor retardasi menunjukkan sifat yang tidak biasa dari lintasan bebas rata-rata neutrino-quark strange. Selain itu, efek penangkapan neutrino secara signifikan menyebabkan fraksi elektron meningkat. Kontribusi elek- tron menurunkan lintasan bebas rata-rata neutrino. Lebih lanjut, lintasan bebas rata-rata neutrino dari pusat bintang quark hingga ke permukaan bintang semakin meningkat. ......The scattering of neutrino with quark star matter through neutral current weak interaction is studied. To describe the quark matter state, MIT bag model is used. The quark star structures can be studied by inserted the quark star equation of state into TOV equation. Here we study the neutrino differential cross section and mean free path. The calculation is performed by using two method; First by considering N-body scattering as N times two body scattering, Second by treating the many body effect properly in N-body scattering. Both approach are compared and studied for the case zero temperature, where we have found that for the first approach, interaction are dominated by the one from down quark, while the second approach the down and strange quarks provide similar contribution. Neutrino mean free path decreases with increasing density, temperature and initial energy neutrino. For finite temperatur case are several factors should be considered, i.e, retardation, Pauli blocking and detailed balancing factors. Pauli blocking and detailed balancing significantly reduce the value of the neutrino mean free path. While the retardation factor indicates unusual behavior of neutrino-strange quark mean free path. In addition, the effect of neutrino trapping is significantly increased the fraction of electrons. Contribution of electrons reduces the value neutrino matter mean free path. Therefore, the neutrino mean free path from the center of quark star to the stellar surface increases.

Abstrak :
The winner of UCL's annual HEP thesis prize, this work describes an analysis of the data from the second flight of the Antarctica Impulsive Transient Antenna (ANITA). ANITA is a balloon-borne experiment that searches for radio signals originating from ultra-high energy neutrinos and cosmic rays interacting with the Antarctic ice or air. The search for ultrahigh energy neutrinos of astrophysical origin is one of the outstanding experimental challenges of the 21st century. The ANITA experiment was designed to be the most sensitive instrument to ultra-high energy neutrinos that originate from the interactions of cosmic rays with the cosmic microwave background. The methodology and results of the neutrino and cosmic ray searches are presented in the thesis.