Related papers: The $\rho^{\pm}-\rho^0$ Mass Splitting Problem

Using a sample of 2.59 x 10^7$ psi(2S) decays collected by the CLEO--c detector, we present results of a search for the decay chain psi(2S) -> pi^0 h_c, h_c -> n(pi^+ pi^-) pi^0, n=1,2,3. We observe no significant signals for n=1 and n=3…

We find a general expression for the one-loop self-energy function of neutral $\rho$-meson due to $\pi^+\pi^-$ intermediate state in a background magnetic field, valid for arbitrary magnitudes of the field. The pion propagator used in this…

It is argued that the search of the J/psi --> f0(980)omega and J/psi --> a0(980)rho decays and the more precise definition of B(J/psi --> f0(980)phi) are the urgent purposes in the J/\psi spectroscopy. It is shown that the study of the…

We review the use of invariant mass distributions in cascade decays to measure the masses of New Physics (NP) particles in scenarios where the final NP cascade particle is invisible. We extend earlier work by exploring further the problem…

The decays of $J/\psi \to \omega K\bar{K}\pi$ and $J/\psi \to \phi K\bar{K}\pi$ are studied using $5.8 \times 10^{7}$ $J/\psi$ events collected with the Beijing Spectrometer (BESII) at the Beijing Electron-Positron Collider (BEPC). The…

We study the $\bar B^0_s \to J/\psi K^+ K^-$, $\bar B^0 \to J/\psi K^+ K^-$, $B^- \to J/\psi K^0 K^-$, $\bar B^0 \to J/\psi \pi^0 \eta$ and $B^- \to J/\psi \pi^- \eta$ decays and compare their mass distributions with those obtained for the…

The statistical physics approach to the number partioning problem, a classical NP-hard problem, is both simple and rewarding. Very basic notions and methods from statistical mechanics are enough to obtain analytical results for the phase…

At present, the measurements of $R_{D^{(*)}}$ and $R_{J/\psi}$ hint at new physics (NP) in $b \to c \tau^- {\bar\nu}$ decays. The angular distribution of ${\bar B} \to D^* (\to D \pi) \, \tau^{-} {\bar\nu}_\tau$ would be useful for getting…

The first observation of the $B_s^0 \to \overline{D}^{*0} \phi$ decay is reported, with a significance of more than seven standard deviations, from an analysis of $pp$ collision data corresponding to an integrated luminosity of 3 fb$^{-1}$,…

Estimation of the $\phi$-divergence between two unknown probability distributions using empirical data is a fundamental problem in information theory and statistical learning. We consider a multi-variate generalization of the data dependent…

We investigate the strong decay $J/\psi\to\rho^+\rho^-\omega$ and the radiative decay $J/\psi\to\gamma\rho^0\omega$, taking into account the $S$-wave $K^*\bar{K}^*$, $\rho \omega$ and $\rho \phi$ final-state interactions that dynamically…

A sample of kinematically identified $K^+ \to \pi^+ \pi^0$ decays obtained with the E949 detector was used to search for the helicity-suppressed decay $\pi^0 \to \nu \bar{\nu}$ resulting in an upper limit of $2.7\times10^{-7}$ at 90%…

Because of their small electromagnetic corrections, the isospin-breaking decays $\eta\to3\pi$ seem to be good candidates for extracting isospin-breaking parameters $ (m_d-m_u)$. This task is unfortunately complicated by large chiral…

We present results on the X(3872), produced in $B^+ \to X(3872) K^+$ and $B^0 \to X(3872) K^0_S$ decays where $X(3872) \to J/\psi \pi^+ \pi^-$. We report the first statistically significant observation of $B^0 \to X(3872) K^0_S$ and measure…

Isospin violating mixing of \rho- and \omega-mesons is reconsidered in terms of propagators. Its influence on various pairs of (\rho^0,\omega)-decays to the same final states is demonstrated. Some of them, (\rho^0,\omega)\to\pi^+\pi^- and…

A search for charmless three-body decays of $B^0$ and $B_{s}^0$ mesons with a $K_{\rm S}^0$ meson in the final state is performed using the $pp$ collision data, corresponding to an integrated luminosity of $1.0\,\mbox{fb}^{-1}$, collected…

We report on the observation of B->D{*}pi+pi-pi-pio decays. The branching ratios for D*+ and D*o are (1.72+/-0.14+/-0.24)% and (1.80+/-0.24+/-0.25)%, respectively. Each final state has a D{*} omega pi- component, with branching ratios…

The NA62 experiment at the CERN SPS reports a study of a sample of $4 \times10^{9}$ tagged $\pi^0$ mesons from $K^+ \to \pi^+ \pi^0 (\gamma)$, searching for the decay of the $\pi^0$ to invisible particles. No signal is observed in excess of…

The complementarity between Chiral Perturbation Theory and the Linear Sigma Model in the scalar channel is exploited to study $\pi^0\pi^0$ production in $\rho$ and $\omega$ radiative decays, where the effects of a low mass scalar resonance…

By including the strong isospin symmetry breaking effects and the electromagnetic contributions between the pseudoscalar mesons, we calculate the phase shifts of the $P$-wave $\pi\pi$ and $K\pi$ scattering up to $\mathcal{O}(p^4)$ in the…