oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Study of the a_0(980) meson via the radiative decay phi->eta pi^0 gamma with the KLOE detector  [PDF]
KLOE Collaboration,F. Ambrosino,A. Antonelli,M. Antonelli,F. Archilli,C. Bacci,P. Beltrame,G. Bencivenni,S. Bertolucci,C. Bini,C. Bloise,S. Bocchetta,F. Bossi,P. Branchini,P. Campana,G. Capon,T. Capussela,F. Ceradini,S. Chi,G. Chiefari,P. Ciambrone,F. Crucianelli,E. De Lucia,A. De Santis,P. De Simone,G. De Zorzi,A. Denig,A. Di Domenico,C. Di Donato,B. Di Micco,A. Doria,M. Dreucci,G. Felici,A. Ferrari,M. L. Ferrer,S. Fiore,C. Forti,P. Franzini,C. Gatti,P. Gauzzi,S. Giovannella,E. Gorini,E. Graziani,W. Kluge,V. Kulikov,F. Lacava,G. Lanfranchi,J. Lee-Franzini,D. Leone,M. Martini,P. Massarotti,W. Mei,S. Meola,S. Miscetti,M. Moulson,S. Müller,F. Murtas,M. Napolitano,F. Nguyen,M. Palutan,E. Pasqualucci,A. Passeri,V. Patera,F. Perfetto,M. Primavera,P. Santangelo,G. Saracino,B. Sciascia,A. Sciubba,A. Sibidanov,T. Spadaro,M. Testa,L. Tortora,P. Valente,G. Venanzoni,R. Versaci,R. Volpe,G. Xu
Physics , 2009, DOI: 10.1016/j.physletb.2009.09.022
Abstract: We have studied the phi->a_0(980) gamma process with the KLOE detector at the Frascati phi-factory DAPhNE by detecting the phi->eta pi^0 gamma decays in the final states with eta->gamma gamma and eta->pi^+ pi^- pi^0. We have measured the branching ratios for both final states: Br(phi->eta pi^0 gamma)=(7.01 +/- 0.10 +/- 0.20)x10^-5 and (7.12 +/- 0.13 +/- 0.22)x10^-5 respectively. We have also extracted the a_0(980) mass and its couplings to eta pi^0, K^+ K^-, and to the phi meson from the fit of the eta pi^0 invariant mass distributions using different phenomenological models.
In-medium Properties of η' Meson  [PDF]
Mariana Nanova for CBELSA/TAPS Collaboration
Physics , 2011, DOI: 10.1016/j.ppnp.2012.01.004
Abstract: Using the Crystal Barrel(CB)/TAPS detector system at the ELSA accelerator facility in Bonn the \eta' photoproduction off nuclei (C, Ca, Nb and Pb) was studied via the hadronic decay channel \eta' -> \pi^0\pi^0\eta . Recent results on the in-medium properties of the \eta'-meson, derived from the transparency ratio measurements, are presented. The absorption of the \eta'-meson in nuclear matter is compared to the properties of other mesons (\eta, \omega).
Study of the process e+e- -> omega pi0 in the phi-meson mass region with the KLOE detector  [PDF]
The KLOE Collaboration,F. Ambrosino,A. Antonelli,M. Antonelli,F. Archilli,P. Beltrame,G. Bencivenni,S. Bertolucci,C. Bini,C. Bloise,S. Bocchetta,F. Bossi,P. Branchini,P. Campana,G. Capon,T. Capussela,F. Ceradini,P. Ciambrone,F. Crucianelli,E. De Lucia,A. De Santis,P. De Simone,G. De Zorzi,A. Denig,A. Di Domenico,C. Di Donato,B. Di Micco,M. Dreucci,G. Felici,M. L. Ferrer,S. Fiore,P. Franzini,C. Gatti,P. Gauzzi,S. Giovannella,E. Graziani,W. Kluge,G. Lanfranchi,J. Lee-Franzini,D. Leone,M. Martini,P. Massarotti,S. Meola,S. Miscetti,M. Moulson,S. Müller,F. Murtas,M. Napolitano,F. Nguyen,M. Palutan,E. Pasqualucci,A. Passeri,V. Patera,F. Perfetto,P. Santangelo,B. Sciascia,A. Sciubba,A. Sibidanov,T. Spadaro,M. Testa,L. Tortora,P. Valente,G. Venanzoni,R. Versaci,G. Xu
Physics , 2008, DOI: 10.1016/j.physletb.2008.09.056
Abstract: We have studied the e+e- -> omegapi0 cross section in the sqrt(s) interval 1000-1030 MeV using the pi+pi-pi0pi0 and pi0pi0gamma final states with a sample of ~600 pb^-1 collected with the KLOE detector at DAFNE. By fitting the observed interference pattern around M_phi for both final states, we extract the ratio of the decay widths Gamma(omega->pi0gamma)/Gamma(omega->pi+pi-pi0) = 0.0897 +- 0.0016 and derive the branching fractions BR(omega -> pi+pi-pi0)= (90.24 +- 0.19)%, BR(omega -> pi0gamma) = (8.09 +- 0.14)%. The parameters describing the e+e- -> omegapi0 reaction around M_\phi are also used to extract the branching fraction for the OZI and G-parity violating phi -> omegapi0 decay: BR(phi->omegapi0) = (4.4 +- 0.6)x10^-5.
The Neutral Decay Modes of the Eta-Meson  [PDF]
B. M. K. Nefkens,J. W. Price
Physics , 2002, DOI: 10.1238/Physica.Topical.099a00114
Abstract: The neutral decay modes of the eta meson are reviewed. The most recent results obtained with the Crystal Ball multiphoton detector at BNL are incorporated. This includes a new, precise result for the slope parameter alpha of the Dalitz plot in eta -> 3pi0 decay and a new, lower branching ratio for eta -> pi0 gamma gamma which is consistent with chiral perturbation theory. Recently-obtained limits are given for novel tests of CP and C invariance based on several rare eta decays.
Meson photoproduction from a transversely polarised target at MAMI  [PDF]
P. Hall Barrientos
Physics , 2011, DOI: 10.1063/1.3701220
Abstract: A new transversely polarised frozen spin target has been developed at MAMI which will be used in conjunction with the photon tagger and the Crystal Ball detector. The new target permits a major new programme of accurate measurement of polarisation observables in meson photoproduction. This contribution presents some of the preliminary analysis from experimental data taken near the threshold and in the region of the $\Delta(1232)$ resonance. Observables will be obtained for the $p\pi^0$ and $n\pi^+$ final states.
Measurement of the B^0 meson properties using partially reconstructed B^0 to D^{*-}pi^+ and B^0 to D^{*-}l^+nu decays with the BABAR detector  [PDF]
The BABAR Collaboration,B. Aubert
Physics , 2000,
Abstract: The two B^0 decay processes B^0 --> D^{*-}pi^+ and B^0 --> D^{*-}l^+nu have been studied by means of a partial reconstruction technique using a data sample collected with the BABAR detector at the PEP-II storage ring. To increase statistics, only the soft pi^- from the decay D^{*-} --> pi^-D^0 was used in association with either an oppositely-charged high-momentum pion or lepton. Events were then identified by exploiting the constraints from the simple kinematics of Y(4S) decays. A clear signature is obtained in each case. The position of the B^0 decay point was obtained from the reconstructed pi^+(l^+)pi^- vertex. The position of the other anti-B^0 in the event was also determined. Taking advantage of the boost given to the Y(4S) system by the asymmetric beam energies of PEP-II, the lifetime of the B^0 meson has been measured from the separation distance between the two vertices along the beam direction. The preliminary results are tau_B0 = 1.55+/-0.05+/-0.07 ps, tau_B0 = 1.62+/-0.02+/-0.09 ps, respectively for the B^0 --> D^{*-}pi^+ and B^0 --> D^{*-}l^+nu channels.
Studies of the $ω$ meson with the KLOE detector  [PDF]
L. Heijkenskj?ld,W. Ikegami Andersson,for the KLOE-2 collaboration
Physics , 2015, DOI: 10.5506/APhysPolB.46.53
Abstract: The paper presents status of three studies involving the $\omega$ meson using data collected by the KLOE detector. The first two projects are feasibility studies performed on simulated data concerning an upper limit measure ment of BR($\Phi \to \omega \gamma$) and the form factor measurement in the $\omega\to\pi^0l^+l^-$ dalitz decay. The third study shows the effect $\pi^0 - \pi^0$ interference has in the $\omega\to\pi^+\pi^-\pi^0$ Dalitz plot when $\omega$ is produced through the $e^+e^-\to\omega\pi^0$ channel.
Study of the decay phi --> pi+pi-pi0 with the KLOE detector  [PDF]
KLOE Collaboration
Physics , 2003, DOI: 10.1016/j.physletb.2005.01.092
Abstract: We present a study of the reaction e+e- --> pi+pi-pi0 at the phi peak W=M(phi)=1019.4 MeV observed with the KLOE detector at Dafne. The reaction is dominated by phi production and decay, e+e- --> phi --> pi+pi-pi0. From a fit to the Dalitz plot density distribution we obtain the rho-meson parameters for its three charge states. We also find the relative amplitudes for phi --> rhopi and phi -> pi+pi-pi0 and the cross-section for e+e- --> omega pi0 with omega --> pi+pi-.
The $(π^-,γγ)$ reaction in nuclei and the $σ$ meson in the medium  [PDF]
L. Roca,E. Oset
Physics , 2003, DOI: 10.1016/S0375-9474(03)01090-X
Abstract: A theoretical analysis of the $(\pi^-,\gamma\gamma)$ reaction in nuclei is made in order to find the viability of this reaction to test modifications of the $\sigma$ meson mass in nuclear matter. The $\pi\pi$ correlation in the scalar-isoscalar channel in nuclear matter could, in principle, manifest itself in this reaction since it plays an important role in the $\pi\pi\to\gamma\gamma$ mechanism. But we conclude that this effect is hardly visible in this reaction due to the strong background of the pion-Bremsstrahlung terms. Only with some special cuts and for some polarization states are the effect visible at the cost of a strong reduction in the cross section.
Results from the Analysis of Crystal Ball Meson Production Measurements at BNL  [PDF]
R. A. Arndt,W. J. Briscoe,I. I. Strakovsky,R. L. Workman
Physics , 2006, DOI: 10.1142/S0217751X07035525
Abstract: The Crystal Ball spectrometer, with its nearly complete angular coverage, is an efficient detector of photon and neutron final states. While installed in the C6 beamline of the Alternating Gradient Synchrotron (AGS) of Brookhaven National Laboratory (BNL), this feature was used in a series of precise measurements of reactions with all-neutral final states. Here we concentrate on the analysis of data from the pion-induced reactions: pi- p --> gamma n, pi- p --> pi0 n, pi- p --> eta n, and pi- p --> pi0 pi0 n.
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.