Related papers: Probing lepton number violating interactions in ra…
We systematically investigate baryon number violating (BNV) nucleon decays into one lepton ($e,\mu,\nu/\bar\nu$) and two pseudoscalar mesons ($\pi\pi,\pi\eta,\pi K$) within the low-energy effective field theory (LEFT) framework. By…
The imminent start of the Large Hadron Collider, which is expected to produce $\sim 10^8$ $t\bar{t}$ pairs per year, provides an unprecedented opportunity for top physics. As the top quark is widely expected to be rather sensitive to…
This is a sequel to our recent work [1] in which we calculated the lepton number violating (LNV) $K^\pm$ decays due to contact dimension-9 (dim-9) quark-lepton effective interactions that are induced at a high energy scale. In this work we…
We investigate the prospects for observing lepton number violation (LNV) by two units, $|\Delta L| = 2$, at the LHC within the leptoquark variant of the Zee Model, where Majorana neutrino masses arise radiatively at one-loop. The model…
We study the complementary tests of lepton number violation in $0\nu\beta\beta$-decay experiments, long-lived particle (LLP) searches at the LHC main detectors ATLAS/CMS, and a proposed far detector MATHUSLA. In the context of a simplified…
Below the electroweak scale, new physics that violates lepton number in two units ($\Delta L = 2$) and is mediated by heavy particle exchange can be parameterized by a dimension-9 low-energy effective Lagrangian. Operators in this…
The ratio $\mathcal{B}(K_L\to\pi^0\nu\bar\nu)/\mathcal{B}(K^+\to\pi^+\nu\bar\nu)$ of the branching fractions of kaon decays $K_L\to\pi^0\nu\bar\nu$ and $K^+\to\pi^+\nu\bar\nu$ has a maximum of about 4.3 under the assumption that the…
We consider the lepton-flavor violating (LFV) lepton-quark dimension-6 operators and analyze their contributions to the LFV leptonic decays of vector, pseudoscalar, and scalar neutral mesons $M\to \ell_1 \ell_2$ as well as to $\mu(\tau)…
Baryon number violation is our most sensitive probe of physics beyond the Standard Model. Its realization through heavy new particles can be conveniently encoded in higher-dimensional operators that allow for model-agnostic analyses. The…
We explore signals of lepton-number-violation in the charm physics sector. We study the four-body $|\Delta L|= 2$ decays of the $D^0$ meson, $D^0 \to P^- \pi^-\mu^+ \mu^+$ ($P = \pi, K$) as an alternative evidence of the Majorana nature of…
Majorana neutrinos in the seesaw model can have sizable mixings through which they can be produced at the Large Hadron Collider (LHC) and show a remarkable Lepton Number Violating (LNV) signature. In this article we study the LNV decay of…
In this work, we study the lepton number violating W boson and top quark decays via intermediate on-shell Majorana neutrinos Nj into three charged leptons and a light neutrino. We discuss the neutrino oscillation effects present in the…
Some models of leptogenesis involve a nearly-degenerate pair of heavy Majorana neutrinos $N_{1,2}$ whose masses can be small, $O({\rm GeV})$. There can be heavy-light neutrino mixing parametrized by $|B_{\ell N}|^2 = 10^{-5}$, which leads…
We develop the consequences of introducing a purely leptonic, lepton number violating non-standard interaction (NSI) and standard model neutrino mixing with a fourth, sterile neutrino in the analysis of short-baseline, neutrino experiments.…
Observation of lepton number violation would represent a groundbreaking discovery with profound consequences for fundamental physics and as such, it has motivated an extensive experimental program searching for neutrinoless double beta…
Rare $K \to \pi \nu \bar \nu$ decays, being dominated by short distance contributions within the Standard Model (SM), open a window for New Physics (NP) searches at low energies. The $ K \to \pi \nu \bar\nu $ branching ratios are expected…
We consider a minimal extension of the Standard Model with one singlet neutrino per generation that can realize resonant leptogenesis at the electroweak scale. In particular, the baryon asymmetry in the Universe can be created by resonant…
The NA62 experiment at the CERN SPS aims to measure the branching ratio of the rare decay $K^+\to\pi^+\nu\bar\nu$ with a relative precision of $\sim10%$. To achieve that goal, it is designed to be exposed to $1.2\times 10^{13}$ $K^+$ decays…
The model of heavy neutral leptons (HNLs) is one of the well-motivated models beyond the standard model (BSM) from both theoretical and phenomenological point of views. It is an indispensable ingredient to explain the puzzle of tiny…
We propose a new model with the Majorana neutrino masses generated at two-loop level, in which the lepton number violation (LNV) processes, such as neutrinoless double beta decays, are mainly induced by the dimension-7 LNV effective…