.
Early data on
K
-
induced reactions off protons are collected and used in a coupled-channel partial-wave analysis (PWA). Data that had been published in the form of Legendre coefficients are ...included in the PWA. In a
primary
fit using
3
*
and
4
*
resonances only, we observe some significant discrepancies with the data. In a systematic search for new
Λ
and
Σ
hyperon resonances, additional candidates are found. The significance of the known and of the additional resonances is evaluated. Seventeen resonances listed with
1
*
or
2
*
and one resonance listed with
3
*
in the Review of Particle Physics cannot be confirmed, five new hyperons are suggested. The partial-wave amplitudes deduced in this analysis are compared to those from other analyses.
The necessity of describing three-nucleon and three-quark systems have led to a constant interest in the problem of three particles. The question of including relativistic effects appeared together ...with the consideration of the decay amplitude in the framework of the dispersion technique. The relativistic dispersion description of amplitudes always takes into account processes connected with the investigated reaction by the unitarity condition or by virtual transitions; in the case of three-particle processes they are, as a rule, those where other many-particle states and resonances are produced. The description of these interconnected reactions and ways of handling them is the main subject of the book.Contents:IntroductionElements of Dispersion Relation Technique for Two-Body Scattering ReactionsSpectral Integral Equation for the Decay of a Spinless ParticleNon-relativistic Three-Body AmplitudePropagators of Spin Particles and Relativistic Spectral Integral EquationsIsobar Model and Partial Wave Analysis. D-Matrix MethodReggeon-Exchange TechniqueSearching for the Quark-Diquark Systematics of BaryonsConclusionReadership: Grudate students and researchers in high energy and particle physics.
.
The orbital angular momentum operator expansion turns out to be a powerful tool to construct the fully covariant partial wave amplitudes of hadron decay reactions and hadron photo- and ...electroproduction processes. In this paper we consider a useful development of the orbital angular momentum operator expansion method. We present the differential technique allowing the direct calculation of convolutions of two orbital angular momentum operators with an arbitrary number of open Lorentz indices. This differential technique greatly simplifies calculations when the reaction subject to the partial wave analysis involves high spin particles in the initial and/or final states. We also present a useful generalization of the orbital angular momentum operators.
Study of the proton-proton collisions at 1683 MeV/c Ermakov, K. N.; Nikonov, V. A.; Rogachevsky, O. V. ...
The European physical journal. A, Hadrons and nuclei,
06/2017, Letnik:
53, Številka:
6
Journal Article
Recenzirano
Odprti dostop
.
The new data on the elastic
pp
and single pion production reaction
p
p
→
p
n
π
+
taken at the incident proton momentum of 1683MeV/
c
are presented. The data on the
p
p
→
p
n
π
+
reaction are ...compared with predictions from the OPE model. To extract the contributions of the leading partial waves, the single-pion production data are analyzed in the framework of the event-by-event maximum-likelihood method together with the data measured earlier.
Low-energy data on the three charge states in
γ
p
→
K
+
(
Σ
π
)
from CLAS at JLab, on
K
-
p
→
π
0
π
0
Λ
and
π
0
π
0
Σ
from the Crystal Ball at BNL, bubble chamber data on
K
-
p
→
π
-
π
+
π
±
Σ
∓
, ...low-energy total cross sections on
K
-
induced reactions, and data on the
K
-
p
atom are fitted with the BnGa partial-wave-analysis program. We find that the data can be fitted well with just one isoscalar spin-1/2 negative-parity pole, the
Λ
(
1405
)
, and background contributions. In a fit with one isocsalar state, the
Λ
(
1405
)
structure can be determined as a dominantly SU(3) singlet state. A fit with two isoscalar singlet states, with imposed properties of the low-mass state, is, however, also not incompatible with data.
.
The two reactions
γ
p
→
K
+
Λ
and
π
-
p
→
K
0
Λ
are analyzed to determine the leading photoproduction multipoles and the pion-induced partial wave amplitudes in slices of the invariant mass. The ...multipoles and the partial-wave amplitudes are simultaneously fitted in a multichannel Laurent+Pietarinen model (L+P model), which determines the poles in the complex energy plane on the second Riemann sheet close to the physical axes. The results from the L+P fit are compared with the results of an energy-dependent fit based on the Bonn-Gatchina (BnGa) approach. The study confirms the existence of several poles due to nucleon resonances in the region at about 1.9 GeV with quantum numbers
J
P
=
1
/
2
+
,
3
/
2
+
,
1
/
2
-
,
3
/
2
-
,
5
/
2
-
.
Photoproduction of baryons decaying into Nπ and Nη Anisovich, A. V.; Sarantsev, A.; Bartholomy, O. ...
The European physical journal. A, Hadrons and nuclei,
09/2005, Letnik:
25, Številka:
3
Journal Article
A coupled-channel analysis of BESIII data on radiative J/ψ decays into ππ, KK¯, ηη and ωϕ has been performed. The partial-wave amplitude is constrained by a large number of further data. The analysis ...finds ten isoscalar scalar mesons. Their masses, widths and decay modes are determined. The scalar mesons are interpreted as mainly SU(3)-singlet and mainly octet states. Octet isoscalar scalar states are observed with significant yields only in the 1500-2100MeV mass region. Singlet scalar mesons are produced over a wide mass range but their yield peaks in the same mass region. The peak is interpreted as scalar glueball. Its mass and width are determined to M=1865±25−30+10MeV and Γ=370±50−20+30MeV, its yield in radiative J/ψ decays to (5.8±1.0)10−3.
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