A sophisticated coupled-channel analysis is presented that combines different processes: the channels
π
0
π
0
η
,
π
0
η
η
and
K
+
K
-
π
0
from
p
¯
p
annihilations, the P- and D-wave amplitudes of the
...π
η
and
π
η
′
systems produced in
π
-
p
scattering, and data from
π
π
-scattering reactions. Hence our analysis combines the data sets used in two independent previous analyses published by the Crystal Barrel experiment and by the JPAC group. Based on the new insights from these studies, this paper aims at a better understanding of the spin-exotic
π
1
resonances in the light-meson sector. By utilizing the K-matrix approach and realizing the analyticity via Chew-Mandelstam functions the amplitude of the spin-exotic wave can be well described by a single
π
1
pole for both systems,
π
η
and
π
η
′
. The mass and the width of the
π
1
-pole are measured to be
(
1623
±
47
-
75
+
24
)
MeV
/
c
2
and
(
455
±
88
-
175
+
144
)
MeV
.
Abstract A sophisticated coupled-channel analysis is presented that combines different processes: the channels $${\pi ^0\pi ^0\eta }$$ π 0 π 0 η , $${\pi ^0\eta \eta }$$ π 0 η η and $${K^+K^-\pi ...^0}$$ K + K - π 0 from $${{\bar{p}}p}$$ p ¯ p annihilations, the P- and D-wave amplitudes of the $$\pi \eta $$ π η and $$\pi \eta ^\prime $$ π η ′ systems produced in $$\pi ^-p$$ π - p scattering, and data from $${\pi \pi }$$ π π -scattering reactions. Hence our analysis combines the data sets used in two independent previous analyses published by the Crystal Barrel experiment and by the JPAC group. Based on the new insights from these studies, this paper aims at a better understanding of the spin-exotic $$\pi _1$$ π 1 resonances in the light-meson sector. By utilizing the K-matrix approach and realizing the analyticity via Chew-Mandelstam functions the amplitude of the spin-exotic wave can be well described by a single $$\pi _1$$ π 1 pole for both systems, $$\pi \eta $$ π η and $$\pi \eta ^\prime $$ π η ′ . The mass and the width of the $$\pi _1$$ π 1 -pole are measured to be $$(1623 \, \pm \, 47 \, ^{+24}_{-75})\, \mathrm {MeV/}c^2$$ ( 1623 ± 47 - 75 + 24 ) MeV / c 2 and $$(455 \, \pm 88 \, ^{+144}_{-175})\, \mathrm {MeV}$$ ( 455 ± 88 - 175 + 144 ) MeV .
Abstract
A sophisticated coupled-channel analysis is presented that combines different processes: the channels
$${\pi ^0\pi ^0\eta }$$
π
0
π
0
η
,
$${\pi ^0\eta \eta }$$
π
0
η
η
and
$${K^+K^-\pi ...^0}$$
K
+
K
-
π
0
from
$${{\bar{p}}p}$$
p
¯
p
annihilations, the P- and D-wave amplitudes of the
$$\pi \eta $$
π
η
and
$$\pi \eta ^\prime $$
π
η
′
systems produced in
$$\pi ^-p$$
π
-
p
scattering, and data from
$${\pi \pi }$$
π
π
-scattering reactions. Hence our analysis combines the data sets used in two independent previous analyses published by the Crystal Barrel experiment and by the JPAC group. Based on the new insights from these studies, this paper aims at a better understanding of the spin-exotic
$$\pi _1$$
π
1
resonances in the light-meson sector. By utilizing the K-matrix approach and realizing the analyticity via Chew-Mandelstam functions the amplitude of the spin-exotic wave can be well described by a single
$$\pi _1$$
π
1
pole for both systems,
$$\pi \eta $$
π
η
and
$$\pi \eta ^\prime $$
π
η
′
. The mass and the width of the
$$\pi _1$$
π
1
-pole are measured to be
$$(1623 \, \pm \, 47 \, ^{+24}_{-75})\, \mathrm {MeV/}c^2$$
(
1623
±
47
-
75
+
24
)
MeV
/
c
2
and
$$(455 \, \pm 88 \, ^{+144}_{-175})\, \mathrm {MeV}$$
(
455
±
88
-
175
+
144
)
MeV
.
A sophisticated coupled-channel analysis is presented that combines different processes: the channels Formula omitted, Formula omitted and Formula omitted from Formula omitted annihilations, the P- ...and D-wave amplitudes of the Formula omitted and Formula omitted systems produced in Formula omitted scattering, and data from Formula omitted-scattering reactions. Hence our analysis combines the data sets used in two independent previous analyses published by the Crystal Barrel experiment and by the JPAC group. Based on the new insights from these studies, this paper aims at a better understanding of the spin-exotic Formula omitted resonances in the light-meson sector. By utilizing the K-matrix approach and realizing the analyticity via Chew-Mandelstam functions the amplitude of the spin-exotic wave can be well described by a single Formula omitted pole for both systems, Formula omitted and Formula omitted. The mass and the width of the Formula omitted-pole are measured to be Formula omitted and Formula omitted.
Abstract
A partial wave analysis of antiproton–proton annihilation data in flight at 900
$$\mathrm {MeV/}c$$
MeV
/
c
into
$${\pi ^0\pi ^0\eta }$$
π
0
π
0
η
,
$${\pi ^0\eta \eta }$$
π
0
η
η
and
...$${K^+K^-\pi ^0}$$
K
+
K
-
π
0
is presented. The data were taken at LEAR by the Crystal Barrel experiment in 1996. The three channels have been coupled together with
$$\pi \pi $$
π
π
-scattering isospin I = 0 S- and D-wave as well as I = 1 P-wave data utilizing the K-matrix approach. Analyticity is treated using Chew–Mandelstam functions. In the fit all ingredients of the K-matrix, including resonance masses and widths, were treated as free parameters. In spite of the large number of parameters, the fit results are in the ballpark of the values published by the Particle Data Group. In the channel
$${\pi ^0\pi ^0\eta }$$
π
0
π
0
η
a significant contribution of the spin exotic
$$I^G=1^-$$
I
G
=
1
-
$$J^{PC}=1^{-+}$$
J
PC
=
1
-
+
$$\pi _1$$
π
1
-wave with a coupling to
$$\pi ^0 \eta $$
π
0
η
is observed. Furthermore the contributions of
$$\phi (1020) \pi ^0$$
ϕ
(
1020
)
π
0
and
$$K^*(892)^\pm K^\mp $$
K
∗
(
892
)
±
K
∓
in the channel
$${K^+K^-\pi ^0}$$
K
+
K
-
π
0
have been studied in detail. The differential production cross section for the two reactions and the spin-density-matrix elements for the
$$\phi (1020)$$
ϕ
(
1020
)
and
$$K^*(892)^\pm $$
K
∗
(
892
)
±
have been extracted. No spin-alignment is observed for both vector mesons. The spin density matrix elements have been also determined for the spin exotic wave.
A partial wave analysis of antiproton–proton annihilation data in flight at 900 MeV/c into π0π0η, π0ηη and K+K-π0 is presented. The data were taken at LEAR by the Crystal Barrel experiment in 1996. ...The three channels have been coupled together with ππ-scattering isospin I = 0 S- and D-wave as well as I = 1 P-wave data utilizing the K-matrix approach. Analyticity is treated using Chew–Mandelstam functions. In the fit all ingredients of the K-matrix, including resonance masses and widths, were treated as free parameters. In spite of the large number of parameters, the fit results are in the ballpark of the values published by the Particle Data Group. In the channel π0π0η a significant contribution of the spin exotic IG=1-JPC=1-+π1-wave with a coupling to π0η is observed. Furthermore the contributions of ϕ(1020)π0 and K∗(892)±K∓ in the channel K+K-π0 have been studied in detail. The differential production cross section for the two reactions and the spin-density-matrix elements for the ϕ(1020) and K∗(892)± have been extracted. No spin-alignment is observed for both vector mesons. The spin density matrix elements have been also determined for the spin exotic wave.
Abstract A partial wave analysis of antiproton–proton annihilation data in flight at 900 $$\mathrm {MeV/}c$$ MeV/c into $${\pi ^0\pi ^0\eta }$$ π0π0η , $${\pi ^0\eta \eta }$$ π0ηη and $${K^+K^-\pi ...^0}$$ K+K-π0 is presented. The data were taken at LEAR by the Crystal Barrel experiment in 1996. The three channels have been coupled together with $$\pi \pi $$ ππ -scattering isospin I = 0 S- and D-wave as well as I = 1 P-wave data utilizing the K-matrix approach. Analyticity is treated using Chew–Mandelstam functions. In the fit all ingredients of the K-matrix, including resonance masses and widths, were treated as free parameters. In spite of the large number of parameters, the fit results are in the ballpark of the values published by the Particle Data Group. In the channel $${\pi ^0\pi ^0\eta }$$ π0π0η a significant contribution of the spin exotic $$I^G=1^-$$ IG=1- $$J^{PC}=1^{-+}$$ JPC=1-+ $$\pi _1$$ π1 -wave with a coupling to $$\pi ^0 \eta $$ π0η is observed. Furthermore the contributions of $$\phi (1020) \pi ^0$$ ϕ(1020)π0 and $$K^*(892)^\pm K^\mp $$ K∗(892)±K∓ in the channel $${K^+K^-\pi ^0}$$ K+K-π0 have been studied in detail. The differential production cross section for the two reactions and the spin-density-matrix elements for the $$\phi (1020)$$ ϕ(1020) and $$K^*(892)^\pm $$ K∗(892)± have been extracted. No spin-alignment is observed for both vector mesons. The spin density matrix elements have been also determined for the spin exotic wave.
A partial wave analysis of antiproton–proton annihilation data in flight at 900
MeV
/
c
into
π
0
π
0
η
,
π
0
η
η
and
K
+
K
-
π
0
is presented. The data were taken at LEAR by the Crystal Barrel ...experiment in 1996. The three channels have been coupled together with
π
π
-scattering isospin I = 0 S- and D-wave as well as I = 1 P-wave data utilizing the K-matrix approach. Analyticity is treated using Chew–Mandelstam functions. In the fit all ingredients of the K-matrix, including resonance masses and widths, were treated as free parameters. In spite of the large number of parameters, the fit results are in the ballpark of the values published by the Particle Data Group. In the channel
π
0
π
0
η
a significant contribution of the spin exotic
I
G
=
1
-
J
PC
=
1
-
+
π
1
-wave with a coupling to
π
0
η
is observed. Furthermore the contributions of
ϕ
(
1020
)
π
0
and
K
∗
(
892
)
±
K
∓
in the channel
K
+
K
-
π
0
have been studied in detail. The differential production cross section for the two reactions and the spin-density-matrix elements for the
ϕ
(
1020
)
and
K
∗
(
892
)
±
have been extracted. No spin-alignment is observed for both vector mesons. The spin density matrix elements have been also determined for the spin exotic wave.
A new highly modular and generic Partial Wave Analysis (PWA) software package including a general framework for future hadron spectroscopy experiments like PANDA is currently under development. The ...aims and present status of the software package are summarized and the first PWA results obtained with the already existing tools are presented. These analyses are mainly focused on important aspects of antiproton proton annihilation processes with relevance for the PANDA experiment. For this purpose Crystal Barrel LEAR data are currently under investigation in order to gain a deeper insight to the production mechanisms of vector mesons. In addition analyses for the identification of resonances in radiative
J
/
ψ
decays from BESIII data are summarized.
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