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Light isovector resonances in $\pi^- p \to \pi^-\pi^-\pi^+ p$ at 190 GeV/${\it c}$

The COMPASS collaboration Akhunzyanov, R. ; Alexeev, M.G. ; Alexeev, G.D. ; et al.
No Journal Information, 2018.
Inspire Record 1655631 DOI 10.17182/hepdata.82958

We have performed the most comprehensive resonance-model fit of $ \pi^-\pi^-\pi^+$ states using the results of our previously published partial-wave analysis (PWA) of a large data set of diffractive-dissociation events from the reaction $\pi^- + p \to \pi^-\pi^-\pi^+ + p_{recoil}$ with a 190 GeV/${\it c}$ pion beam. The PWA results, which were obtained in 100~bins of three-pion mass, 0.5 < $m_{3\pi}$ < 2.5 GeV/${\it c}^2$, and simultaneously in 11 bins of the reduced four-momentum transfer squared, 0.1 < $t'$ < 1.0 (GeV/${\it c})^2$, are subjected to a resonance-model fit using Breit-Wigner amplitudes to simultaneously describe a subset of 14 selected waves using 11 isovector light-meson states with $J^{PC} = 0^{-+}$, $1^{++}$, $2^{++}$, $2^{-+}$, $4^{++}$, and spin-exotic $1^{-+}$ quantum numbers. The model contains the well-known resonances $\pi$(1800), $a_1$(1260), $a_2$(1320), $\pi_2$(1670), $\pi_2$(1880), and $a_4$(2040). In addition, it includes the disputed $\pi_1$(1600), the excited states $a_1$(1640), $a_2$(1700), and $\pi_2$(2005), as well as the resonance-like $a_1$(1420). We measure the resonance parameters mass and width of these objects by combining the information from the PWA results obtained in the 11 $t'$ bins. We extract the relative branching fractions of the $\rho$(770)$\pi$ and $f_2$(1270)$\pi$ decays of $a_2$(1320) and $a_4$(2040), where the former one is measured for the first time. In a novel approach, we extract the $t'$ dependence of the intensity of the resonances and of their phases. The $t'$ dependence of the intensities of most resonances differs distinctly from the $t'$ dependence of the nonresonant components.

2 data tables

Decay phase-space volume $I_{aa}$ for the 14 selected partial waves as a function of $m_{3\pi}$, normalized such that $I_{aa}(m_{3\pi} = 2.5~\text{GeV}/c^2) = 1$. The wave index $a$ represents the quantum numbers that uniquely define the partial wave. The quantum numbers are given by the shorthand notation $J^{PC} M^\varepsilon [$isobar$] \pi L$. We use this notation to label the decay phase-space volume in the column headers. The labels are identical to the ones used in the column headers of the table of the transition amplitudes. $I_{aa}$ is calculated using Monte Carlo integration techniques for fixed $m_{3\pi}$ values, which are given in the first column, in the range from 0.5 to 2.5 GeV/$c^2$ in steps of 10 MeV/$c^2$. The statistical uncertainties given for $I_{aa}$ are due to the finite number of Monte Carlo events. $I_{aa}(m_{3\pi})$ is defined in Eq. (6) in the paper and appears in the resonance model in Eqs. (19) and (20).

Real and imaginary parts of the normalized transition amplitudes $\mathcal{T}_a$ of the 14 selected partial waves in the 1100 $(m_{3\pi}, t')$ cells (see Eq. (12) in the paper). The wave index $a$ represents the quantum numbers that uniquely define the partial wave. The quantum numbers are given by the shorthand notation $J^{PC} M^\varepsilon [$isobar$] \pi L$. We use this notation to label the transition amplitudes in the column headers. The $m_{3\pi}$ values that are given in the first column correspond to the bin centers. Each of the 100 $m_{3\pi}$ bins is 20 MeV/$c^2$ wide. Since the 11 $t'$ bins are non-equidistant, the lower and upper bounds of each $t'$ bin are given in the column headers. The transition amplitudes define the spin-density matrix elements $\varrho_{ab}$ for waves $a$ and $b$ according to Eq. (18). The spin-density matrix enters the resonance-model fit via Eqs. (33) and (34). The transition amplitudes are normalized via Eqs. (9), (16), and (17) such that the partial-wave intensities $\varrho_{aa} = |\mathcal{T}_a|^2$ are given in units of acceptance-corrected number of events. The relative phase $\Delta\phi_{ab}$ between two waves $a$ and $b$ is given by $\arg(\varrho_{ab}) = \arg(\mathcal{T}_a) - \arg(\mathcal{T}_b)$. Note that only relative phases are well-defined. The phase of the $1^{++}0^+ \rho(770) \pi S$ wave was set to $0^\circ$ so that the corresponding transition amplitudes are real-valued. In the PWA model, some waves are excluded in the region of low $m_{3\pi}$ (see paper and [Phys. Rev. D 95, 032004 (2017)] for a detailed description of the PWA model). For these waves, the transition amplitudes are set to zero. The tables with the covariance matrices of the transition amplitudes for all 1100 $(m_{3\pi}, t')$ cells can be downloaded via the 'Additional Resources' for this table.


STUDY OF K*- (890) AND K*- (1430) PRODUCTION IN THE REACTION K- P ---> ANTI-K0 PI- P AT 100-GEV/C AND 175-GEV/C

Bromberg, C. ; Dickey, J. ; Fox, G. ; et al.
Phys.Rev. D29 (1984) 2469-2475, 1984.
Inspire Record 205297 DOI 10.17182/hepdata.23731
8 data tables

No description provided.

No description provided.

No description provided.

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STUDY OF A2 PRODUCTION IN THE REACTION PI- P ---> K0 K- P AT 50-GEV/C, 100-GEV/C, AND 175-GEV/C

Bromberg, C. ; Dickey, J.o. ; Fox, G. ; et al.
Phys.Rev. D27 (1983) 1-11, 1983.
Inspire Record 191493 DOI 10.17182/hepdata.23901
6 data tables

No description provided.

RAW CROSS SECTION WITHIN MASS CUTS.

No description provided.

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RESONANCE PRODUCTION IN THE REACTION PI+- P ---> K0(S) K+- P AT 30-GEV/C AND 50-GEV/C

Cleland, W.e. ; Delfosse, A. ; Dorsaz, P.a. ; et al.
Nucl.Phys. B208 (1982) 228-261, 1982.
Inspire Record 184972 DOI 10.17182/hepdata.34061
5 data tables

No description provided.

D(SIG)/DT FOR 50 GEV IN RESONANCE REGIONS.

No description provided.

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Study of a2 and a3 meson production in pi p collisions at 4.45 gev/c

Beketov, G.V. ; Zombkovskii, S.M. ; Konovalov, B.S. ; et al.
Yad.Fiz. 13 (1971) 765-771, 1971.
Inspire Record 69508 DOI 10.17182/hepdata.19293
1 data table

CROSS SECTIONS VERY SENSITIVE TO BACKGROUND SUBTRACTION.


Study of the a2- from the reaction pi- p ---> k(s)0 k- p at 4.5 gev/c

Crennell, D.J. ; Gordon, H.A. ; Lai, Kwan-Wu ; et al.
Phys.Lett. B35 (1971) 185-188, 1971.
Inspire Record 69246 DOI 10.17182/hepdata.28512
3 data tables

No description provided.

No description provided.

No description provided.


Production of $\rho^\pm$, $G^\pm$(1700), $A2^\pm$, $K^{*\pm}$(890) and $K^{*\pm}$(1420) at 50-{GeV}/c

Delfosse, A. ; Dorsaz, P.A. ; Extermann, P. ; et al.
Nucl.Phys. B183 (1981) 349-366, 1981.
Inspire Record 170363 DOI 10.17182/hepdata.34280

Mesons decaying into π 0 or η and one charged meson were studied using a liquid-argon calorimeter in a non-magnetic double-arm spectrometer. Cross sections and energy dependences are presented. The ϱ ± production mechanisms are discussed in detail: ω and π exchange contribute the largest fractions, but also A 2 exchange is present. ϱ ± production by ω exchange is shown to follow the energy behaviour predicted by the Regge trajectory α ω ( t ) = 0.4 − | t |.

2 data tables

Axis error includes +- 0.0/0.0 contribution (13 TO 25////STATISTICAL ERRORS ARE SMALLER THAN THE SYSTEMATIC ERRORS).

No description provided.


Strange-particle production in pi- p collisions at 11.2 gev/c leading to two charged final particles

Dameri, M. ; Tomasini, G. ; Trevisan, U. ; et al.
Nuovo Cim. A9 (1972) 1-27, 1972.
Inspire Record 78421 DOI 10.17182/hepdata.37457
1 data table

No description provided.


Diffractive Production of 3 $\pi$ States at 63-{GeV} and 94-{GeV}

The ACCMOR collaboration Daum, C. ; Hertzberger, L. ; Hoogland, W. ; et al.
Nucl.Phys. B182 (1981) 269-336, 1981.
Inspire Record 156369 DOI 10.17182/hepdata.34314
4 data tables

SEE C. DAUM ET AL., PL 89B, 276 (1980) (<a href=http://durpdg.dur.ac.uk/scripts/reacsearch.csh/TESTREAC/red+486> RED = 486 </a>), AND THE RECORD (<a href=http://durpdg.dur.ac.uk/scripts/reacsearch.csh/TESTREAC/red+420> RED = 420 </a>) OF THE GENEVA CONFERENCE PREPRINT, B. ALPER ET AL. (1979).

SEE C. DAUM ET AL., PL 89B, 281 (1980) (<a href=http://durpdg.dur.ac.uk/scripts/reacsearch.csh/TESTREAC/red+487> RED = 487 </a>), AND THE RECORD (<a href=http://durpdg.dur.ac.uk/scripts/reacsearch.csh/TESTREAC/red+419> RED = 419 </a>) OF THE GENEVA CONFERENCE PREPRINT, G. THOMPSON ET AL. (1979).

SEE C. DAUM ET AL., PL 89B, 285 (1980) (<a href=http://durpdg.dur.ac.uk/scripts/reacsearch.csh/TESTREAC/red+488> RED = 488 </a>), AND THE RECORD (<a href=http://durpdg.dur.ac.uk/scripts/reacsearch.csh/TESTREAC/red+421> RED = 421 </a>) OF THE GENEVA CONFERENCE PREPRINT, B. ALPER ET AL. (1979).

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CHARACTERISTICS OF MULTI - PION PRODUCTION AT 3.9-GeV/c and 11.9-GeV/c

Johnson, A.D. ; Peters, M.W. ; Stenger, V.J. ; et al.
Phys.Rev. D7 (1973) 1314, 1973.
Inspire Record 83722 DOI 10.17182/hepdata.22171
4 data tables

No description provided.

No description provided.

No description provided.

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Measurement of Diffractive 3 $\pi$ Production on a Polarized Target at 17-{GeV}/$c$

Chabaud, V. ; de Groot, J. ; Hyams, B. ; et al.
Nucl.Phys. B178 (1981) 401-420, 1981.
Inspire Record 154064 DOI 10.17182/hepdata.34349
1 data table

No description provided.


Results From a $\pi^-$p Slow Proton Trigger Experiment at 12 GeV/c

Evangelista, C. ; Ghidini, B. ; Palano, A. ; et al.
Nucl.Phys. B178 (1981) 197-241, 1981.
Inspire Record 153471 DOI 10.17182/hepdata.34350
9 data tables

No description provided.

No description provided.

No description provided.

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A2 Meson Production at 63-{GeV} and 94-{GeV} in the Reaction $\pi^- p \to \pi^- \pi^- \pi^+ p$

The ACCMOR collaboration Daum, C. ; Hertzberger, L. ; Hoogland, W. ; et al.
Phys.Lett. B89 (1980) 276-280, 1980.
Inspire Record 143255 DOI 10.17182/hepdata.27274
1 data table

No description provided.


ELASTIC AND TOTAL PI+ PI- CROSS-SECTIONS FROM A HIGH STATISTICS MEASUREMENT OF THE REACTION PI- P ---> PI+ PI- N AT 63-GeV/c.

Weilhammer, P. ; Berglund, A. ; Chabaud, V. ; et al.
Conference Paper, 1979.
Inspire Record 148986 DOI 10.17182/hepdata.75420
5 data tables

INTEGRATED 2- S-WAVE INTENSITY FOR 1500 TO 1800 MEV, INCLUDING SIGNIFICANT BACKGROUND.

No description provided.

No description provided.

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PRISM Plot Analysis of the Reaction pi- p --> pi- pi- pi+ p at 13-GeV/c

Gaidos, J.A. ; Yen, W.L. ;
Phys.Rev. D19 (1979) 22-42, 1979.
Inspire Record 135845 DOI 10.17182/hepdata.24296
2 data tables

No description provided.

No description provided.


A2- Production in the Reaction $\pi^- p \to K^- K^0_S p$ at 9.8-{GeV} and 18.8-{GeV}

The CERN-Munich collaboration Chabaud, V. ; Hyams, B. ; Jones, C. ; et al.
Nucl.Phys. B145 (1978) 349-366, 1978.
Inspire Record 131631 DOI 10.17182/hepdata.34875
4 data tables

FITS WITH CONSTANT BACKGROUNDS. A TWO-PARAMETER LINEAR BACKGROUND GIVES MUCH LARGER ERRORS.

INTEGRATED OVER M(K AK) = 1.20 TO 1.42 GEV.

No description provided.

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Backward Production in $\pi^- p \to p_f \pi^+ \pi^- \pi^-$ Reaction at 9-{GeV}/$c$ and 12-{GeV}/$c$

Ferrer, A. ; Bouquet, B. ; D'Almagne, B. ; et al.
Nucl.Phys. B142 (1978) 77-107, 1978.
Inspire Record 130740 DOI 10.17182/hepdata.34939
3 data tables

No description provided.

U-HELICITY JACKSON FRAME.

U-HELICITY JACKSON FRAME.


A Study of A2 and $g$ Resonance Production in $\pi^- p \to K^- K^0 p$

Martin, Alan D. ; Ozmutlu, E.N. ; Baldi, R. ; et al.
Nucl.Phys. B140 (1978) 158-178, 1978.
Inspire Record 129933 DOI 10.17182/hepdata.35032
2 data tables

No description provided.

No description provided.


A Study of Isospin = 1 Meson States Using 10-{GeV}/$c K^- K^0$ Production Data

Martin, Alan D. ; Ozmutlu, E.N. ; Baldi, R. ; et al.
Phys.Lett. B74 (1978) 417-421, 1978.
Inspire Record 129502 DOI 10.17182/hepdata.27459
1 data table

CROSS SECTIONS FROM FITTING MASS SPECTRUM. THE RESONANT AMPLITUDE CONTRIBUTIONS ALSO GIVEN IN PAPER.


K0(s) k- decay of a2- produced by 20.3-gev/c pi- on hydrogen

Foley, K.J. ; Love, W.A. ; Ozaki, S. ; et al.
Phys.Rev. D6 (1972) 747-756, 1972.
Inspire Record 73969 DOI 10.17182/hepdata.22252

We present the results of an analysis of data for the reaction π−p→KS0K−p at 20.3-GeV/c incident π momentum. We find that the K0K− effective-mass spectrum shows a single peak in the A2 region which is well fitted by a Breit-Wigner shape. The data in the A2-peak region are inconsistent with the split-A2 shape reported earlier. The distribution in t of the A2 events shows a forward dip followed by an exponential falloff. The A2 decay angular distribution is well fitted by a single resonance with quantum numbers JP=2+. The results of an analysis of the density-matrix elements for this reaction are given.

2 data tables

CORRECTED FOR UNSEEN K0 DECAYS AND FOR BREIT-WIGNER RESONANCE TAILS.

INCLUDING THE DENSITY MATRIX ELEMENTS OMITTED FROM THIS FIT GIVES NO SIGNIFICANT IMPROVEMENT AND THE NEW PARAMETERS ARE CLOSE TO ZERO. LIM INDICATES FITTED VALUE LIMITED FROM VARIATION BY PHYSICAL CONSTRAINTS FROM OTHER PARAMETERS.


Pion and Nucleon Dissociation in pi- p --> pi- pi+ pi- p at 205-GeV/c

Bingham, H.H. ; Chew, D.M. ; Fretter, W.B. ; et al.
Phys.Lett. B51 (1974) 397-401, 1974.
Inspire Record 90046 DOI 10.17182/hepdata.27930
1 data table

No description provided.


Meson production by $\delta$ exchange in $\pi^- p$ interactions at 4-GeV/c

Scharre, D.L. ; Chapman, J.W. ; Ely, R.P. ; et al.
Phys.Rev. D17 (1978) 2853, 1978.
Inspire Record 121388 DOI 10.17182/hepdata.24432
5 data tables

Axis error includes +- 15/15 contribution.

No description provided.

Axis error includes +- 15/15 contribution.

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Cross sections for resonance production in the reaction pi+- p ---> p pi+- pi+ pi- at 16-GeV/c, as obtained by a maximum likelihood fit

The Aachen-Berlin-Bonn-CERN-Heidelberg collaboration Honecker, R. ; Rumpf, K. ; Tsanos, N. ; et al.
Nucl.Phys. B50 (1972) 157-165, 1972.
Inspire Record 84326 DOI 10.17182/hepdata.32751
2 data tables

TWO PARTICLE RESONANCE CROSS SECTIONS.

CHANNEL FRACTIONS FROM THE FITS. THE AUTHORS WARN AGAINST DERIVING CROSS SECTIONS FOR THREE-PARTICLE RESONANCES.


Backward Enhancement in the a1 Region and a2 Production in the Region pi- p --> p(f) pi+ pi- pi- at 9-GeV/c and 12-GeV/c

Ferrer, A. ; Bouquet, B. ; D'Almagne, B. ; et al.
Phys.Lett. B74 (1978) 287-291, 1978.
Inspire Record 134669 DOI 10.17182/hepdata.27446
1 data table

No description provided.


A2- Production in pi- p Interactions at 3.9-GeV/c

Losty, M.J. ; Chaloupka, V. ; Montanet, L. ; et al.
Phys.Lett. B56 (1975) 96-100, 1975.
Inspire Record 91185 DOI 10.17182/hepdata.27856
18 data tables

CORRECTED FOR ALL A2(1310)- DECAY MODES.

No description provided.

<RHO0 PI-> DATA.

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