Related papers: Breaking the Grossman-Nir Bound in Kaon Decays
We present a preliminary measurement of the CP asymmetry in singly Cabibbo-suppressed D+ -> K-K+\pi+ decays and in the resonant decays D+ -> \phi \pi+ and D+ -> K*0 K+. We use a data sample of 79.9 fb^{-1} recorded by the BABAR detector.…
We consider four lepton-number violating (\lv) processes: (a) neutrinoless double-beta decay (0\nu\beta\beta), (b) Delta L = 2 tau decays, (c) Delta L = 2 rare meson decays and (d) nuclear muon-positron conversion. In the absence of exotic…
We study the phenomenology of heavy neutral leptons (HNLs) in $B$-meson decays as probes of physics beyond the Standard Model. Focusing on the leptonic channels $B \to \mu N$ and $B \to \tau N$, we constrain the allowed regions in the…
We have searched for a bound state of kaon and pion denoted by $X$. The $X$ was conjectured to explain the so-called $\Theta^+$ resonance as a bound state of kaon, pion and nucleon. This model explains almost all properties of the…
In this work, the lepton-number-violating processes in $|\Delta L|=2$ decays of $\Lambda_b^0$ baryon, $\Lambda_b^0 \to p \pi^+\mu^- \mu^-$ and $\Lambda_b^0 \to \Lambda_c^+ \pi^+\mu^- \mu^-$, are investigated for the first time, via an…
By employing the perturbative QCD(pQCD) factorization approach, we calculate the branching ratios and CP violating asymmetries of the four $\bar{B}_s^0 \to K\pi$ and $K K $ decays, with the inclusion of all known next-to-leading order (NLO)…
The NA48/2 and $\text{NA62}\text{-}{\text{R}_\text{K}}$ experiments at the CERN SPS collected a large sample of charged kaon decays in flight. $\text{NA62}\text{-}{\text{R}_\text{K}}$ was running in 2007-08 with a highly efficient minimum…
Motivated by the prospects for an improved test of lepton universality in K -> l \nu decays by the NA62 experiment at CERN, we study predictions for the possible lepton non-universality in K -> l \nu decays in supersymmetric models.…
We present preliminary measurements of branching fractions and CP-violating asymmetries in decays of B mesons to two-body final states containing a K0. The results are based on a data sample of approximately 227 million Upsilon(4S) decays…
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 KOTO experiment has recently performed a search for neutral Kaons decaying into neutral pions and a pair of neutrinos. Three events were observed in the KOTO signal region, with an expected background of about 0.05. Since no clear…
We study the contributions of the non-standard neutrino interactions (NSIs) to the rare meson decays of $K^{+}\to \pi^{+} \nu\bar{\nu}$ and $D^{+}\to \pi^{+} \nu\bar\nu$. We show that both decays could provide strong constraints on the free…
We discuss a potential discrepancy in an approximate relation among $B \to K \pi$ rates which, with increased statistical significance, would imply new physics in $\Delta I=1$ transitions. An approximate relation between CP-violating rate…
Weakly interacting K --> pi X^0 emission with m_{X^0} \simeq m_{pi^0} is out of sight of the current K^+ --> pi^+ nu nubar study, but it can be sensed by the K_L --> pi^0 nu nubar search. This evades the usual Grossman-Nir bound of B(K_L…
The quantities $\epsilon_K^\prime$ and $\epsilon_K$ measure the amount of direct and indirect CP violation in $K\to \pi\pi$ decays, respectively. Using the recent lattice results from the RBC and UKQCD Collaborations and a new compact…
Top flavour-changing neutral decays are extremely suppressed within the Standard Model (SM) by the GIM mechanism, but can reach observable rates in some of its extensions. We compute the branching ratios for t -> c gamma and t -> c g in…
A decade long search for the rare kaon decay to pi^+nunu-bar has been pursued by E787. Two signal events are observed, giving a measurement of the branching ratio Br(K^+ -> PI^+NUNU-BAR)=1.57^+1.75_-0.82 x 10^-10 and a constraint on the…
The KOTO II experiment is proposed to measure the branching ratio of the decay $K_L\to\pi^0\nu\bar{\nu}$ at J-PARC. With a beamline to extract long-lived neutral kaons at 5 degrees from a production target, the single event sensitivity of…
We consider a possibility that $R$-parity violating interactions of particles which do not involve the first generation have large (up to 1) coupling constants, $\Lambda$. Such couplings, if exist, could have a number of phenomenological…
We stress the importance of precise measurements of rare decays $K^+\rightarrow\pi^+\nu\bar\nu$, $K_L\rightarrow\pi^0\nu\bar\nu$, $K_{L,S}\to\mu^+\mu^-$ and $K_{L,S}\to\pi^0\ell^+\ell^-$ for the search of new physics (NP). This includes…