Related papers: TAUOLA update for decay channels with $e^+e^-$ pai…
The rare second-class decay mode of the $\tau$ into $\eta\pi\nu$ could be observed for the first time at Belle II. It is important to try to derive a reliable evaluation of the branching fraction and of the energy distribution of this mode…
Because of properties of QED, the bremsstrahlung corrections to decays of particles or resonances can be calculated, with a good precision, separately from other effects. Thanks to the widespread use of event records such calculations can…
An improved formalism of the two-neutrino double-beta decay ($2\nu\beta\beta$-decay) rate is presented, which takes into account the dependence of energy denominators on lepton energies via the Taylor expansion. Till now, only the leading…
We present a new Monte-Carlo generator, {\tt ee$\in$MC}, for the simulation of $e^{+}e^{-} \to \mu^{+} \mu^{-} (\gamma) $, $e^{+}e^{-} \to \tau^{+}\tau^{-} (\gamma) $ and $\tau$ lepton decays which is suitable for $e^{+}e^{-}$ colliders…
We present the system for versioning two packages: the TAUOLA of tau lepton decay and PHOTOS for radiative corrections in decays. The following features can be chosen in automatic or semi-automatic way: (1) format of the common block…
Because of the fine--tuning problem in classical Majoron models in recent years several new models were invented. It is pointed out that double beta decays with Majoron emission depend on new matrix elements, which have not been considered…
Software development in high energy physics experiments offers unique experience with rapidly changing environment and variety of different standards and frameworks that software must be adapted to. As such, regular methods of software…
We present simulation studies in preparation for analyzing $\tau^-\to\pi^-\pi^+\pi^-\nu_\tau$ in data from the Belle experiment at the KEK $\mathrm{e}^+\mathrm{e}^-$ collider. Analyzing this decay can shed light on the $\mathrm{a}_1(1260)$…
Various Monte Carlo programs, developed either by small groups or widely available, have been used to calculate the effects of decays of radioactive chains, from the original parent nucleus to the final stable isotopes. These chains include…
We present a software framework for Belle II that reconstructs B mesons in many decay modes with minimal user intervention. It does so by reconstructing particles in user-supplied decay channels, and then in turn using these reconstructed…
Decays of B mesons into final states containing a tau lepton are sensitive to new charged-current interactions that break lepton-flavor universality. These decays have been studied only at e+e- colliders, where the low-background…
The decays $\bar{B} \rightarrow D^{(*)} \tau^- \bar{\nu}_\tau$ are good probes to new physics beyond the Standard Model. The ratios of branching fractions $R(D^{(*)}) \equiv \mathit{BF}(\bar{B} \rightarrow D^{(*)} \tau^- \bar{\nu}_\tau) /…
We have studied hadronic tau decay modes involving an eta meson using 490 fb^{-1} of data collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. The following branching fractions have been measured: B(tau- -> K- eta…
We have measured branching fractions of hadronic $\tau$ decays involving an $\eta$ meson using 485 fb^{-1} of data collected with the Belle detector at the KEKB asymmetric-energy e^+e^- collider. We obtain the following branching fractions:…
Certain CP-odd momentum correlations in the production and subsequent decay of $\tau$ pairs in $e^+ e^-$ collisions are enhanced significantly when the $e^+$ and $e^-$ beams are longitudinally polarized. These may be used to probe the real…
We have observed new channels for $\tau$ decays with an $\eta$ in the final state. We study 3-prong tau decays, using the $\eta\to\gamma\gamma$ and $\eta\to 3\piz$ decay modes and 1-prong decays with two $\piz$'s using the…
Inclusive Monte-Carlo samples are indispensable for signal selection and background suppression in many high energy physics experiments. A clear knowledge of the physics processes involved in the samples, including the types of processes…
In this work, a physics process known since quite long ago, double-gamma decay ($\gamma\gamma$), has been revisited from a new perspective: providing valuable insights into neutrinoless double-beta decay ($0\nu\beta\beta$) nuclear matrix…
Many experiments whose goal is the search for neutrino-less double beta decay are taking data or in a final construction stage. The need for a tool that allows for an objective comparison between the sensitivity of different experiments is…
Measurements of angular correlations between initial and final particles in $\beta$ decay remain one of the most promising ways of probing the Standard Model and looking for new physics. As experiments reach unprecedented precision well…