Related papers: Probing invisible particles with charm

We study exotic Higgs decays $h \to Z X$, with $X$ an invisible beyond the Standard Model (SM) particle, resulting in a semi-dark final state. Such exotic Higgs decays may occur in theories of axion-like-particles (ALPs), dark photons or…

The $B$ meson semileptonic modes to $\rho(770)$ and $a_1 (1260)$ are useful to pin down possible non Standard Model effects. The 4d differential $\bar B \to \rho(\pi \pi) \ell^- \bar \nu_\ell$ and $ \bar B \to a_1 (\rho \pi) \ell^- \bar…

Polarized $\Lambda_b \to \Lambda \gamma$ decays at the Z pole are shown to be well suited for probing a large variety of New Physics effects. A new observable is proposed, the angular asymmetry between the $\Lambda_b$ spin and photon…

We investigate semileptonic sum rules in heavy-to-light charm decays, motivated by analogous relations in $b \to c$ and $b \to u$ transitions. Focusing on the $c \to d\overline{\ell}\nu$ decays, $D \to \pi\overline{\ell}\nu$, $D \to…

Using the residual symmetry approach, we propose a complex extension of the scaling ansatz on $M_\nu$ which allows a nonzero mass for each of the three light neutrinos as well as a nonvanishing $\theta_{13}$. Leptonic Dirac CP violation…

All pieces of concrete evidence for phenomena outside the standard model (SM) - neutrino masses and dark matter - are consistent with the existence of new degrees of freedom that interact very weakly, if at all, with those in the SM. We…

If dark photons are massless, they couple to standard-model particles only via higher dimensional operators, while the kinetic mixing with photons, which motivates most of the current experimental searches, is absent. We consider the effect…

In this work, we explore the potential of probing the inelastic dark matter (DM) model with an extra U(1)D gauge symmetry at the Large Hadron Collider, ForwArd Search ExpeRiment and Super Tau Charm Factory. To saturate the observed DM relic…

We present standard model (SM) estimates for exclusive $c \to u \gamma$ processes in heavy quark and hybrid frameworks. Measured branching ratios ${\cal{B}}(D^0 \to (\phi, \bar K^{*0}) \gamma)$ are at or somewhat exceeding the upper range…

The Standard Model of particle physics is still lacking an understanding of the generation and nature of neutrino masses. A favorite theoretical scenario (the see-saw mechanism) is that both Dirac and Majorana mass terms are present,…

The study of processes involving the weak decays of the charm quark offers unique possibilities to test the Standard Model from the up-type sector and to probe different New Physics scenarios. In here we focus on the rare decays…

We point out new ways to search for charmless baryonic B decays: baryon pair production in association with $\eta^\prime$ is very likely as large as or even a bit larger than two body $K\pi/\pi\pi$ modes. We extend our argument, in weaker…

A search for invisible decays of the $\Lambda$ baryon is carried out in the process $J/\psi\to\Lambda\bar{\Lambda}$ based on $(1.0087\pm0.0044)\times10^{10}$ $J/\psi$ events collected with the BESIII detector located at the BEPCII storage…

One of the major challenges of modern physics is to decipher the nature of dark matter. Astrophysical observations provide ample evidence for the existence of an invisible and dominant mass component in the observable universe, from the…

In this report I review recent results in the field of rare decays at the Tevatron CDF II and D0 experiments. The presentation is focused on rare decays of charm and bottom mesons with two muons in the final state. This includes…

We consider extending the Standard Model by an anomaly-free and possibly flavour non-universal $U(1)_X$ gauge symmetry, whose breaking gives a $Z^\prime$ boson that does not affect electroweak precision observables at tree-level or via…

The production of heavy sterile neutrinos from $\pi^-,K^-$ decay at rest yields charged leptons with negative helicity (positive for $\pi^+,K^+$). We obtain the branching ratio for this process and argue that a Stern-Gerlach filter leads to…

Following the intriguing hints of deviations from the Standard Model in rare B meson decays, searches for rare and forbidden decays of charm hadrons become a hot topic again. We present recent results on Flavour Changing Neutral Current…

We study weak radiative $|\Delta c|=|\Delta u|=1$ decays of the charmed anti-triplett ($\Lambda_c$, $\Xi_c^{+}$, $\Xi_c^{0}$) and sextet ($\Sigma_c^{++}$, $\Sigma_c^+$, $\Sigma_c^0$, $\Xi_c^{\prime +}$, $\Xi_c^{\prime 0}$, $\Omega_c$)…

Most of the matter in the Universe is in the form of dark matter, which has evaded detection so far. Ultralight axionlike particles (ALPs) are a class of dark matter candidates that produce measurable signatures in the form of oscillating…