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Precision test of baryogenesis


The Baryon-antibaryon Asymmetry of the Universe (BAU) is confirmed by two distinct cosmological measurements: the light element abundances from Big Bang Nucleosynthesis (BBN) and the temperature anisotropy in the Cosmic Microwave Background (CMB). Although the Standard Model of particle physics and cosmology contain all the necessary ingredients to generate a BAU through the so-called baryogenesis, they turn out to be insufficient and new physics is called for. Baryogenesis which relies on baryon number violation due to the nontrivial ElectroWeak (EW) vacuum had to occur above the EW scale around 100 GeV and in principle could occur at temperature as high as the Grand Unified Theories (GUTs) scale of 10^{16} GeV after cosmic inflation took place. Another important evidence of new physics, the tiny neutrino mass of eV scale naturally points to lepton number violation not far from the GUTs scale through the so-called seesaw mechanism. This lepton number violation opens up a new avenue of baryogenesis through leptogenesis. If baryogenesis were to occur at temperature much higher than 100 GeV, direct experimental test will be challenging. In this project, we propose to indirectly verify high scale baryogenesis through precision test. In particular, we aim to derive precise analytical expressions which allow to calculate the generated BAU taking into account various important effects like that of lepton flavors and spectator particles in the thermal bath. Incorporating these results, we will develop a public software which will allow to test more fundamental models like GUTs where one needs to reproduce low energy observables as well as the observed BAU. (AU)

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Scientific publications (6)
(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)
FONG, CHEE SHENG. osmic evolution of lepton flavor charge. HYSICAL REVIEW, v. 105, n. 4 FEB 8 2022. Web of Science Citations: 0.
FONG, CHEE SHENG; RAHAT, MOINUL HOSSAIN; SAAD, SHAIKH. Low-scale resonant leptogenesis in SU(5) GUT with T-13 family symmetry. Physical Review D, v. 104, n. 9 NOV 29 2021. Web of Science Citations: 0.
BERNAL, NICOLAS; FONG, CHEE SHENG. Dark matter and leptogenesis from gravitational production. Journal of Cosmology and Astroparticle Physics, n. 6 JUN 2021. Web of Science Citations: 0.
FONG, C. S.; GREGOIRE, T.; TONERO, A. Testing quasi-Dirac leptogenesis through neutrino oscillations. Physics Letters B, v. 816, MAY 10 2021. Web of Science Citations: 0.
FONG, CHEE SHENG. Baryogenesis in the standard model and its supersymmetric extension. Physical Review D, v. 103, n. 5 MAR 26 2021. Web of Science Citations: 0.
NISHI, CELSO C.; FONG, CHEE SHENG. Leptogenesis in the mu tau basis. Journal of High Energy Physics, n. 7 JUL 21 2020. Web of Science Citations: 0.

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