27–30 Apr 2026
Palais des papes, Avignon
Europe/Paris timezone

B-Mesogenesis: The mechanism revisited

27 Apr 2026, 15:20
10m
Chambre du Trésorier (Palais des papes, Avignon)

Chambre du Trésorier

Palais des papes, Avignon

Speaker

Martha Ulloa Calzonzin (University of Florida)

Description

The B-Mesogenesis mechanism aims to explain the baryon asymmetry of the Universe and dark matter through the CP violating oscillations and subsequent decays of $B$-Mesons in the early Universe at times right before BBN, $T \simeq (5-20)\,{\rm MeV}$. In this work, we point out that the photo-disassociation process $\gamma+B^0\to B^{0\star}$ that was not accounted for in the original studies is the most effective in leading to decoherence of CP violating oscillations. By providing a first principle calculation of the mechanism and considering this process we find that the efficiency of the mechanism is reduced by a factor of $\sim 2-100$ depending upon the effective reheating temperature in the model. Furthermore, we solve for BBN within the mechanism and find that consistency with observations requires $T_{\rm RH}>5.3\,{\rm MeV}$. These two findings imply that the required CP asymmetries and branching ratios of $B$ mesons into baryons and missing energy should at least be a factor of 10 larger than it was expected. Overall, we find that the mechanism is in tension with the lack of new-physics signals in these laboratory observables and may be ruled out experimentally already.

Author

Martha Ulloa Calzonzin (University of Florida)

Co-authors

Benjamin Grinstein (Univ. of California San Diego (US)) Jorge Martin Camalich (Instituto de Astrofísica de Canarias) Maksym Ovchynnikov (CERN) Miguel Escudero Abenza (CERN)

Presentation materials