Near Threshold Enhancement of the P P-bar Mass Spectrum in J/Psi Decay

Near Threshold Enhancement of the P P-bar Mass Spectrum in J/Psi Decay PDF Author:
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Languages : en
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We investigate the nature of the near-threshold enhancement in the p {bar p} invariant mass spectrum of the reaction J/[Psi] → [gamma] p {bar p} reported recently by the BES Collaboration. Using the Juelich N {bar N} model we show that the mass dependence of the p {bar p} spectrum close to the threshold can be reproduced by the S-wave p {bar p} final state interaction in the isospin I=1 state within the Watson-Migdal approach. However, because of our poor knowledge of the N {bar N} interaction near threshold and of the J/[Psi] → [gamma] p {bar p} reaction mechanism and in view of the controversial situation in the decay J/[Psi] → [pi]° p {bar p}, where no obvious signs of a p {bar p} final state interaction are seen, explanations other than final state interactions cannot be ruled out at the present stage.

Near Threshold Enhancement of the P P-bar Mass Spectrum in J/Psi Decay

Near Threshold Enhancement of the P P-bar Mass Spectrum in J/Psi Decay PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
We investigate the nature of the near-threshold enhancement in the p {bar p} invariant mass spectrum of the reaction J/[Psi] → [gamma] p {bar p} reported recently by the BES Collaboration. Using the Juelich N {bar N} model we show that the mass dependence of the p {bar p} spectrum close to the threshold can be reproduced by the S-wave p {bar p} final state interaction in the isospin I=1 state within the Watson-Migdal approach. However, because of our poor knowledge of the N {bar N} interaction near threshold and of the J/[Psi] → [gamma] p {bar p} reaction mechanism and in view of the controversial situation in the decay J/[Psi] → [pi]° p {bar p}, where no obvious signs of a p {bar p} final state interaction are seen, explanations other than final state interactions cannot be ruled out at the present stage.

Observation of a Near-Threshold Enhancement in the P-anti-p Mass Spectrum from Radiative J/psi --] Gamma-p-anti-p Decays

Observation of a Near-Threshold Enhancement in the P-anti-p Mass Spectrum from Radiative J/psi --] Gamma-p-anti-p Decays PDF Author:
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Languages : en
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We observe a narrow enhancement near 2m[sub p] in the invariant mass spectrum of p[bar p] pairs from radiative J/[psi][yields][gamma]p[bar p] decays. No similar structure is seen in J/[psi][yields][pi][sup 0] p[bar p] decays. The results are based on an analysis of a 58 million event sample of J/[psi] decays accumulated with the BESII detector at the Beijing electron-positron collider. The enhancement can be fit with either an S- or P-wave Breit Wigner resonance function. In the case of the S-wave fit, the peak mass is below 2m[sup p] at M= 1859[sub -10][sup+3] (stat)[sub -25][sup+5] (sys) MeV/c[sup 2] and the total width is[Lambda]

Analysis of the P P-bar Mass Spectrum in J/Psi

Analysis of the P P-bar Mass Spectrum in J/Psi PDF Author: A. W. Thomas
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Languages : en
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The near-threshold enhancement in the p p-bar invariant mass spectrum of the reaction J/Psi --> gamma p p-bar, observed in an experiment by the BES Collaboration, is analysed. It is shown, within the Watson-Migdal approach to final state interactions, that the mass dependence of the p p-bar spectrum close to the threshold can be reproduced by the S-wave p p-bar interaction of the Jülich N N-bar model in the isospin I=1 state. Difficulties in the consistent interpretation of the p invariant mass spectrum of the reaction J/Psi --> pi^0 p p-bar, where there are no obvious signs for a final state interaction, are discussed.

Analysis of the P P-bar Mass Spectrum in J

Analysis of the P P-bar Mass Spectrum in J PDF Author:
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Category :
Languages : en
Pages :

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Book Description
The near-threshold enhancement in the p p-bar invariant mass spectrum of the reaction J/Psi --> gamma p p-bar, observed in an experiment by the BES Collaboration, is analysed. It is shown, within the Watson-Migdal approach to final state interactions, that the mass dependence of the p p-bar spectrum close to the threshold can be reproduced by the S-wave p p-bar interaction of the Jülich N N-bar model in the isospin I=1 state. Difficulties in the consistent interpretation of the p invariant mass spectrum of the reaction J/Psi --> pi^0 p p-bar, where there are no obvious signs for a final state interaction, are discussed.

High Energy Physics Index

High Energy Physics Index PDF Author:
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ISBN:
Category : Particles (Nuclear physics)
Languages : en
Pages : 640

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Energy Research Abstracts

Energy Research Abstracts PDF Author:
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Category : Power resources
Languages : en
Pages : 1468

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INIS Atomindex

INIS Atomindex PDF Author:
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Category : Nuclear energy
Languages : en
Pages : 1286

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Study of B Meson Decays to Ppbarh Final States

Study of B Meson Decays to Ppbarh Final States PDF Author: Tetiana B. Hryn'ova
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Category :
Languages : en
Pages : 165

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B mesons are unique among well-established non-quarkonium mesons in their ability to decay into baryons. Baryonic B decays offer a wide range of interesting areas of study: they can be used to test our theoretical understanding of rare decay processes involving baryons, search for direct CP violation and study low-energy QCD. This thesis presents measurements of branching fractions and a study of the decay dynamics of the charmless three-body decays of B meson into p{bar p}h final states, where h = {pi}{sup +}, K{sup +}, K{sub S}{sup 0}, K*{sup 0} or K*{sup +}. With a sample of 232 million {Upsilon}(4S) {yields} B{bar B} events collected with the BaBar detector, we report the first observation of the B {yields} p{bar p}K*{sup 0} decay, and provide improved measurements of branching fractions of the other modes. The distribution of the three final-state particles is of particular interest since it provides dynamical information on the possible presence of exotic intermediate states such as the hypothetical pentaquark states {Theta}*{sup ++} and {Theta}{sup +}in the m{sub pK{sup +}} and m{sub pK{sub S}{sup 0}} spectra, respectively, or glueball states (such as the tensor glueball f{sub J}(2220)) in the m{sub p{bar p}} spectrum. No evidence for exotic states is found and upper limits on the branching fractions are set. An enhancement at low p{bar p} mass is observed in all the B {yields} p{bar p}h modes, and its shape is compared between the decay modes and with the shape of the time-like proton form factor. A Dalitz plot asymmetry in B {yields} p{bar p}K{sup +} mode suggests dominance of the penguin amplitude in this decay and disfavors the possibility that the low mass p{bar p} enhancement originates from the presence of a resonance below threshold (such as the recently seen baryonium candidate at 1835 MeV/c{sup 2}). We also identify decays of the type B {yields} X{sub c{bar c}}h {yields} p{bar p}h, where h = K{sup +}, K{sub S}{sup 0}, K*{sup 0} or K*{sup +}, and X{sub c{bar c}} = {eta}{sub c} or J/{psi}. In particular, we report on the evidence of the B {yields} {eta}{sub c}K*{sup +} decay and provide a measurement of the width of {eta}{sub c}.

ERDA Energy Research Abstracts

ERDA Energy Research Abstracts PDF Author: United States. Energy Research and Development Administration. Technical Information Center
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ISBN:
Category : Force and energy
Languages : en
Pages : 1680

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ERDA Energy Research Abstracts

ERDA Energy Research Abstracts PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 640

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