arXiv subjects

Lovre Pavičić

Publications and source records attributed to Lovre Pavičić.

3 recordsLinked to original sources

arXiv2026

Probing the neutrino mass through semileptonic meson decays

We argue that a detailed analysis of semileptonic decays can test the possibility of a massive neutrino. The key observable, related to the forward-backward asymmetry, is exactly zero for a massless neutrino but becomes non-zero if the neutral lepton is heavy and interacts with Standard Model fields via left-handed operators. For right-handed interactions, this quantity differs significantly from zero even for a massless right-handed neutrino. We demonstrate this explicitly using the example of a pseudoscalar meson decaying into another pseudoscalar meson. A similar discussion applies to decays into a vector meson, with an additional subtlety addressed in this work.

hep-ph↗

arXiv2025

Right-handed interactions in puzzling $B$-decays

We explain the difference between the measured decay widths of $b \to c τν$ processes and of $B\to Kν\barν$ and their values predicted in the Standard Model by introducing the right-handed interactions both to quarks and to leptons. At low energy scales, in addition to the Standard Model particles, we assume the presence of an additional neutral lepton (right-handed neutrino). We then show a specific realization of such a scenario in a model with a single scalar leptoquark ($S_1$), and discuss the corresponding phenomenology.

hep-ph↗

arXiv2024

$R_{D^{(*)}}$ and survival of the fittest scalar leptoquark

Motivated by the long-standing discrepancy in lepton flavor universality ratios $R_D$ and $R_{D^{\ast}}$ we assess the status of scalar leptoquark states $R_2$, $\widetilde R_2$ and $S_1$ which can in principle provide a desired enhancement of $\mathcal{B}(B\to D^{(\ast )}τν)$ in a minimal setup with two Yukawa couplings only. We consider unavoidable low-energy constraints, $Z$-pole measurements as well as high-$p_T$ constraints. After setting mass of each leptoquark to $1.5$ TeV we find that of all considered states only $S_1$ leptoquark, coupled to both chiralities of leptons and quarks, is still a completely viable solution while the scenario with $R_2$ is in growing tension with $Γ(Z \to ττ)$ and with the LHC constraints on the di-tau tails at high-$p_T$. We comment on the future experimental tests of $S_1$ scenario.

hep-ph↗