Search results for "plot"
showing 10 items of 830 documents
Measurement of theI=1/2Kπ S-wave amplitude from Dalitz plot analyses ofηc→KK¯πin two-photon interactions
2016
We study the processes γγ→K^0_SK^±π^∓ and γγ→K^+K^−π^0 using a data sample of 519 fb^(−1) recorded with the BABAR detector operating at the SLAC PEP-II asymmetric-energy e+e− collider at center-of-mass energies at and near the Υ(nS) (n=2, 3, 4) resonances. We observe ηc decays to both final states and perform Dalitz plot analyses using a model-independent partial wave analysis technique. This allows a model-independent measurement of the mass-dependence of the I=1/2 Kπ S-wave amplitude and phase. A comparison between the present measurement and those from previous experiments indicates similar behavior for the phase up to a mass of 1.5 GeV/c^2. In contrast, the amplitudes show very marked…
Search for exotics at $BABAR$
2014
One of the most intriguing puzzles in hadron spectroscopy are the numerous charmonium-like states observed in the last decade, including charged states that are manifestly exotic. The $BABAR$ experiment has extensively studied those in B meson decays, initial state radiation processes and two photon reactions. The study of the process $B \rightarrow J/\psi \phi K$, with a search for the resonant states X(4140) and X(4270) in their decays to $J/\psi \phi$, will be highlighted. The recent results of the Dalitz analysis of $\eta_c$ to 3 pseudoscalar mesons, via 2-photon interactions, will be presented in this report
New results from crystal barrel
1993
Results are presented on meson spectroscopy, two-body final states and meson decay modes observed in\(\bar pp\) annhilation at rest by the Crystal Barrel experiment at LEAR.
The role of N*(2120) nucleon resonance in KΛ(1520) photon and hadronic productions
2013
The associate $K\Lambda(1520)$ photon and hadronic production in the $\gamma p \to K^+\Lambda(1520)$, $p p \to p K^+ \Lambda(1520)$ and $\pi^- p \to K^0 \Lambda(1520)$ reactions are investigated within the effective Lagrangian approach and the isobar model. We are interested in the contribution from the $N^*(2120)$ (previously called $N^*(2080)$) resonance, which has a significant coupling to the $K\Lambda(1520)$ channel. The theoretical results show that the current experimental data for the $\gamma p \to K^+\Lambda(1520)$ reaction favor the existence of the $N^*(2120)$ resonance, and that these measurements can be used to further constrain its properties. We present results, including the…
The End Point Tagger physics program at A2@MAMI
2017
The A2-Collaboration uses a beam of real photons from the tagged photon facility at the electron accelerator MAMI in Mainz, Germany, to study photo-produced mesons. A new tagging device allows access to the higher photon beam energy range of 1.4 to 1.6 GeV. A large dataset containing more than 6 million η ′ and roughly 29 million ω decays has been obtained. Analyses are ongoing, including a study of the cusp effect and Dalitz plot in η ′ → ηπ 0 π 0 , giving insight to the π π scattering length and the structure of the ηππ system, as well as the measurement of the electromagnetic transition form factor in η ′ → e + e − γ , a cross section measurement of γ p → 3 π 0 , and branching ratio anal…
Measurement of η′ → ηπ+π− with KLOE and KLOE-2
2012
The investigation of η ′ → ππη allows to study ππ and ηπ interactions and the possible influence of the scalar states f 0 (600) and a 0 (980) on the decay dynamics. 1.7 fb −1 of data taken with the KLOE detector at the DAΦ NE e+ e− collider have been analyzed with respect to the charged decay mode η ′ → π + π − η . 7900 ± 90 event candidates have been extracted and can be used for a Dalitz plot analysis.
Measurement of theγγ*→π0transition form factor
2009
We study the reaction e+e- --> e+e-pi0 and measure the gamma gamma* --> pi0 transition form factor in the momentum transfer range from 4 to 40 GeV^2. The analysis is based on 442 fb^-1 of integrated luminosity collected at PEP-II with the BABAR detector at e+e- center-of-mass energies near 10.6 GeV.
Three-body final state interaction in η→ 3π updated
2017
In view of the recent high-statistic KLOE data for the η→π+π−π0 decay, a new determination of the quark mass double ratio has been done. Our approach relies on a dispersive model that takes into account rescattering effects between three pions via subenergy unitarity. The latter is essential to reproduce the Dalitz plot distribution. A simultaneous description of the KLOE and WASA-at-COSY data is achieved in terms of just two real parameters. From a global fit, we determine Q=21.6±1.1. The predicted slope parameter for the neutral channel α=−0.025±0.004 is in reasonable agreement with the PDG average value.
$a_0-f_0$ mixing in the Khuri-Treiman equations for $\eta\to 3\pi$
2015
A reliable determination of the isospin breaking double quark mass ratio from precise experimental data on $\eta\to 3\pi$ decays should be based on the chiral expansion of the amplitude supplemented with a Khuri-Treiman type dispersive treatment of the final-state interactions. We discuss an extension of this formalism which allows to estimate the effects of the $a_0(980)$ and $f_0(980)$ resonances and their mixing on the $\eta\to 3\pi$ amplitudes. Matrix generalisations of the equations describing elastic $\pi\pi$ rescattering with $I=0,\,2$ are introduced which accomodate both $\pi\pi/K\bar{K}$ and $\eta\pi/K\bar{K}$ coupled-channel rescattering. Isospin violation induced by the physical …
Exclusive semileptonic heavy meson decays including lepton mass effects
1990
We discuss the exclusive semi-leptonic (s.l.) bottom meson decaysB→D(D*)+l+v where we include non-zero lepton mass effects in the kinematics and dynamics. We develop the general formalism for the non-zero lepton mass case. We then look at how rates, spectra and angular correlations are affected by non-zero lepton masses in the context of a specific spectator quark model. Numerical results are presented for s.l. decays involving thee-, μ- and τ-leptons. We also discuss the s.l. decaysB→π(ρ),D→K(K*) and the free quark decay model.