816 research outputs found
Phase Motion of the Scalar Amplitudes in , Decays
We make a direct and model-independent measurement of the low
mass phase motion in the decay. Our preliminary
results show a strong phase variation, compatible with the isoscalar
meson. This result confirms our previous result where we found
evidence for the existence of this scalar particle using full Dalitz-plot
analysis. We apply the Amplitude Difference (AD) method to the same Fermilab
E791 data sample used in the preceding analysis. We also give an example of how
we extract the phase motion of the scalar amplitude, looking at the
in decay.Comment: Invited talk given at Scalar Meson Workshop, SUNY Institute of
Technology, May 2003, Utica, NY. 14 pages, 13 figure
Charmless B decays in modes with similar tree and penguin contributions
Charmless decays are dominated by contributions from the short distance
amplitudes from tree level and penguin loop-level amplitudes. The Tree
contribution presents a weak phase . The relationship between these two
amplitudes can generated a CP asymmetry depending from the relative amount
among them in a particular decay. In multi-body charmless decays, these
relative contribution can change along the phase space, given a non isotropic
distribution of CP asymmetries in the Dalitz plot. Two recent LHCb analyses
involving charmless multi-body B decays are discussed: the obsevation of CP
asymmetries in the phase space of the three-body decays and ; and the angular analysis of the
decay.Comment: Proceedings to FPCP-2014- Flavor Physics \& CP Violation, Marseille,
France, May 25-30, 201
Light Scalar Mesons , and in Charm Meson Decays
We present recent results on scalar light mesons based on Dalitz plot
analyses of charm decays from Fermilab experiment E791. Scalar mesons are found
to have large contributions to the decays studied, and
. From the first decay, we find good evidence for
the existence of the light and broad meson and we measure its mass and
width. We find strong evidence for the meson from
decay and measure its mass and width. We also present
the results obtained for the parameters through the decay. These results demonstrate the importance of charm
decays as a new environment for the study of light meson physics.Comment: 10 pages, 2 figures. To appear in proceedings of VIII International
Workshop on Hadron Physics 2002 Rio Grande do Sul, Brazil. World Scientific
editio
Charm rescattering contribution in rare decay
Following the experimental results from LHCb on the rare decay , we investigate the possibility where this process is dominated by
a double charm rescattering. The decay to double charm channels have a
weak topology that is favoured in comparison with the direct production of
in the final state, suppressed by quark annihilation. The decay
amplitude for with decaying first to double charm
channels is described by a charm penguin diagram, represented by charm hadronic
triangle loops, which reach the final state of interest after or transitions. We show that these
processes give rise to non-resonant amplitudes with a clear signature in the
Dalitz plot. In a near future, the new data from LHCb run II will be able to
confirme if the main hypotheses of this work is correct and the dominant
mechanism to produce from the decay of is through charm
rescattering
Dalitz plot analysis and branching fraction measurement of D+ and Ds+ -> pi+pi-pi+
Fermilab fixed target experiment E791 obtained a sample of
events of and 848 events of decays. We find respectively and . Using a
coherent amplitude analysis to fit the Dalitz plot of the decay, we find strong evidence for a scalar resonance of mass
MeV/ and width
MeV/, compatible with what is expected for the isoscalar meson
>. The fraction accounts for approximately half of all three-charged-pion
decays of the . From the Dalitz plot analysis of the decay events, we find significant contributions from the channels
, ,
, , and . We also present new
measurement of the masses and widths of the isoscalar resonances and
.Comment: 4 pages, 4 figures, talk presented in BEACH2000, Valencia, Spai
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