Strange Decays of Nonstrange Baryons
Strange Decays of Nonstrange Baryons

Author:

Publisher:

Published: 1998

Total Pages:

ISBN-13:

DOWNLOAD EBOOK

The strong decays of excited nonstrange baryons into the final states [Lambda]K, [Sigma]K, and for the first time into [Lambda](1405)K, [Lambda](1520)K, [Sigma](1385)K, [Lambda]K{sup *}, and [Sigma]K{sup *}, are examined in a relativized quark pair creation model. The wave functions and parameters of the model are fixed by previous calculations of N[pi] and N[pi][pi], etc., decays. The results show that it should be possible to discover several new negative parity excited baryons and confirm the discovery of several others by analyzing these final states in kaon production experiments. They also establish clear predictions for the relative strengths of certain states to decay to [Lambda](1405)K and [Lambda](1520)K, which can be tested to determine if a three-quark model of the [Lambda](1405)K is valid. The authors results compare favorably with the results of partial wave analyses of the limited existing data for the [Lambda]K and [Sigma]K channels. They do not find large [Sigma]K decay amplitudes for a substantial group of predicted and weakly established negative-parity states, in contrast to the only previous work to consider decays of these states into the strange final states [Lambda]K and [Sigma]K.

Quasi Two-body Decays of Nonstrange Baryons
Quasi Two-body Decays of Nonstrange Baryons

Author:

Publisher:

Published: 1993

Total Pages: 17

ISBN-13:

DOWNLOAD EBOOK

We examine the decays of nonstrange baryons to the final states Delta Pi, NRho, NEta, NEta', Nw, N.5 (1440)Pi, and Delta 3/2+(1600)Pi, in a relativized pair-creation (^3Po) model which has been developed in a previous study of the NPi decays of the same baryon states. As it is our goal to provide a guide for the possible discovery of new baryon states at CEBAF and elsewhere, we examine the decays of resonances which have already been seen in the partial-wave analyses, along with those of states which are predicted by the quark model but which remain undiscovered. The level of agreement between our calculation and the available widths from the partial-wave analyses in encouraging.

Decays of Non-strange Positive Parity Excited Baryons in the 1
Decays of Non-strange Positive Parity Excited Baryons in the 1

Author:

Publisher:

Published: 2005

Total Pages:

ISBN-13:

DOWNLOAD EBOOK

The decays of non-strange positive parity baryons via emission of a pseudo-scalar meson are studied in the framework of the 1/Nc expansion to order 1/Nc. In particular, the pionic decays of the l=0 Roper baryons and of the l=2 baryons in the mass interval 1680-1950 MeV are analyzed using the available partial decay widths. Decay widths by emission of an eta meson are shown to be suppressed by a factor 1/Nc2 with respect to the pionic ones.

Decays of J
Decays of J

Author:

Publisher:

Published: 1982

Total Pages:

ISBN-13:

DOWNLOAD EBOOK

We present results for the decays of psi(3100) into baryon and hyperon final states. The sample studied here consists of 1.3 million produced psi decays. The decays into nonstrange baryons agree well with currently established results, but with better statistics. In addition, significant resonance formation in multibody final states is observed. The decay psi .-->. anti pp.gamma., the first direct photon decay of the psi involving baryons in the final state, is presented and the theoretical implications of the decays are briefly explored. Several new decays of the psi involving strange baryons are explored, including the first observations of three body final states involving hyperons. The I-spin symmetry of the strong decay psi .-->. baryons has clearly been observed. The reduced matrix elements for psi .-->. B anti B are presented for final states of different SU(3) content. The B anti B results are in excellent agreement with the psi being an SU(3) singlet as are the results for psi .-->. B10 anti B10. We present the first evidence for the SU(3) violating decays of the type psi .-->. B8 anti B10 + c.c. Angular distributions for psi .-->. B8 anti B8 are presented and compared with theoretical predictions. Statistics are limited, but the data tends to prefer other than a 1 + Cos2theta distribution.

Decays of J/psi (3100) to Baryon Final States
Decays of J/psi (3100) to Baryon Final States

Author:

Publisher:

Published: 1982

Total Pages:

ISBN-13:

DOWNLOAD EBOOK

We present results for the decays of psi(3100) into baryon and hyperon final states. The sample studied here consists of 1.3 million produced psi decays. The decays into nonstrange baryons agree well with currently established results, but with better statistics. In addition, significant resonance formation in multibody final states is observed. The decay psi .-->. anti pp.gamma., the first direct photon decay of the psi involving baryons in the final state, is presented and the theoretical implications of the decays are briefly explored. Several new decays of the psi involving strange baryons are explored, including the first observations of three body final states involving hyperons. The I-spin symmetry of the strong decay psi .-->. baryons has clearly been observed. The reduced matrix elements for psi .-->. B anti B are presented for final states of different SU(3) content. The B anti B8 results are in excellent agreement with the psi being an SU(3) singlet as are the results for psi .-->. B10 anti B10. We present the first evidence for the SU(3) violating decays of the type psi .-->. B8 anti B10 + c.c. Angular distributions for psi .-->. B8 anti B8 are presented and compared with theoretical predictions. Statistics are limited, but the data tends to prefer other than a 1 + Cos2theta distribution.

Decays of Negative Parity Non-strange Baryons in the 1/Nc Expansion
Decays of Negative Parity Non-strange Baryons in the 1/Nc Expansion

Author:

Publisher:

Published: 2004

Total Pages:

ISBN-13:

DOWNLOAD EBOOK

The decays of non-strange negative parity baryons via the emission of single [pi] and [eta] mesons are analyzed in the framework of the 1/N{sub c} expansion. A basis of spin-flavor operators is established to that order, and with this basis the different partial wave decay amplitudes are obtained. The unknown effective coefficients are determined by fitting to the S- and D-wave partial widths as provided by the PDG. A full set of relations between widths that result at the leading order, i.e. order N{sub c0}, is given and tested with the data. The rather large errors of the input partial widths, that result from the often discrepant results for the resonance parameters from different analyses of the data, lead to a rather good fit at the leading order N{sub c0}. The next to leading order fit fails for that reason to pin down with satisfactory accuracy the effective sub leading effective constants.

Physics In Collision - Proceedings Of The 15th International Conference
Physics In Collision - Proceedings Of The 15th International Conference

Author: Krzysztof Rybicki

Publisher: World Scientific

Published: 1996-01-23

Total Pages: 539

ISBN-13: 9814548057

DOWNLOAD EBOOK

This book presents a comprehensive overview of high energy physics. It covers the whole range of results from the colliders and fixed-target experiments as well as the astrophysics topics related to particle physics. Also discussed are the problems of proton structure, electroweak physics, non-perturbative QCD and heavy quarks.

N-pi Decays of Baryons in a Relativized Model
N-pi Decays of Baryons in a Relativized Model

Author:

Publisher:

Published: 1992

Total Pages: 1994

ISBN-13:

DOWNLOAD EBOOK

We calculate teh N pi decay amplitudes of baryon resonances ina semi-relativistic version of the 3P0 model of hadron decays. We use relativized wave functions for the baryons and mesons, and include an intuitive modification of the usual 3P0 model. Our results are in reasonable agreement with the reported amplitudes for all known non-strange resonances, and confirm a proposed solution to the mystery of the 'missing' states.