Analysis of the Reaction K- p --> K- pi- pi+ p at 40-GeV/c

The CERN-Serpukhov Boson Spectrometer Group collaboration Antipov, Yu.M. ; Ascoli, G. ; Busnello, R. ; et al.
Nucl.Phys.B 86 (1975) 381-402, 1975.
Inspire Record 90643 DOI 10.17182/hepdata.32087

The reaction K − p → K − π − π + p has been measured at 25 and 40 GeV/ c at the Serpukhov Proton Accelerator. The production cross section at 25 and 40 GeV/ c as a function of momentum transfer and K ππ mass is presented, and results of the partial-wave analysis of the K ππ system yielding information about Q(1300), K ∗ (1400) and L(1770) mesons are discussed.

3 data tables

No description provided.

K** DEFINED BY 1.30 < M(K PI PI) < 1.54 GEV.

L IS DEFINED AS THE 2- STATE WITH 1.6 < M(K PI PI) < 1.9 GEV.


Comparison of the Reactions K+- p ---> q+- p at Incident Momentum 8.25-GeV/c

The Athens-Brussels-CERN-Democritos-Liverpool-Mons-Vienna collaboration Stergiou, A. ; Apostolakis, A. ; Michaelides, P. ; et al.
Nucl.Phys.B 102 (1976) 1-19, 1976.
Inspire Record 91607 DOI 10.17182/hepdata.36021

In this paper a comparison of the general features of the reactions K ± p→Q ± p (1) at incident momentum 8.25 GeV/ c is presented. The relevant data derive from events yielding four-constraint fits to the reactions K ± p→K ± π + π − p in exposures of the CERN 2m HBC to RF-separated K + and K − beams. The (K ππ ) effective mass distributions, production angular distributions in the Q region (1.2⩽ M (K ππ )⩽1.5 GeV) and corresponding decay angular distributions are exhibited, and background effects due to N ∗ and Δ production are systematically studied. In particular, it is found that the distributions d σ /d t ′ and d σ /d t for reactions (1) are adequately described by exponential functions over the interval 0.05–0.35 GeV 2 , and exhibit a cross-over effect for momentum transfer squared −0.1 GeV 2 . For both reactions a flattening of d σ /d t ′ for t ′ < 0.05 GeV 2 is observed. By studying the Chew-Low plots and the effects of the different cuts it was found that this flattening cannot be attributed to amplitudes with net s -channel helicity flip different from zero, at least at these energies.

2 data tables

ABOUT 7 PCT RELATIVE NORMALIZATION UNCERTAINTY FOR K+ AND K- SAMPLES.

FITS TO D(SIG)/DT AND D(SIG)/DTP FOR Q+ AND Q- PRODUCTION TO DETERMINE CROSS-OVER POSITIONS. DATA HAVE MASS CUTS TO SELECT K*0 AND REMOVE DEL++ AND DEL0. MIN IS THE MINIMUM VALUE OF -T FOR THE RELEVANT (K PI PI) MASS.


Diffractive Production of Strange Mesons at 63-{GeV}

The ACCMOR collaboration Daum, C. ; Hertzberger, L. ; Hoogland, W. ; et al.
Nucl.Phys.B 187 (1981) 1-41, 1981.
Inspire Record 164180 DOI 10.17182/hepdata.34277

Nearly 200 000 examples of the diffractive process K − p → K − π − π + p at 63 GeV have been obtained using a two magnet spectrometer equipped with Čerenkov counters for secondary particle identification. In addition some 2000 examples of the process K − p → ω K − p have been obtained. The K ππ data have been subjected to partial-wave analysis. The dominant J P = 1 + system couples to K ∗ π , in both S and D waves, ϱ K, κπ and ε K. The data confirm the existence of two J P = 1 + Q mesons and their masses, widths and branching ratios are given. The ifωK data show that the couplings of the Q mesons to ω K are approximately equal to the couplings to ϱ 0 K. The two 1 + nonets expected in the quark model are discussed in the light of this and other recent experiments. There is strong evidence for a broad J P = 0 − resonance at about 1.46 GeV. At higher masses, structure in the J P = 2 − partial waves establishes the existence of at least one J P = 2 − L meson.

1 data table

JP=1+ S-WAVE PARTIAL WAVE INTENSITIES AND TOTAL INTENSITY FOR Q-REGION. THE <K* PI> INTENSITY IS DOMINATED BY QHIGH. THE <K RHO> AND <KAPPA PI> INTENSITIES ARE DOMINATED BY QLOW.


Evidence for Different Polarization Properties of the rho K and K* (890) pi States of the 1+ Wave in the Q Region

The Aachen-Berlin-CERN-London-Vienna collaboration Otter, G. ; Rudolph, G. ; Rumph, K. ; et al.
Nucl.Phys.B 93 (1975) 365-386, 1975.
Inspire Record 99251 DOI 10.17182/hepdata.32005

A partial-wave analysis has been performed on the (K − π − π + ) system produced in the reaction K − p → K − π − π + p at 10 and 16 GeV/ c . In the Q mass region it is found that the two dominant states, K ∗ π and Kπ, both in 1 + S wave, are produced with different polarisations, helicity being approximately conserved in the t -channel for K ∗ π and in the s -channel for Kπ. This is in contradiction with the assumption that the amplitude can be factorised into “production” and “decay” parts, and hence that the two amplitudes are fully coherent. The phase variation of the two states do not indicate simple resonance behaviour. It is concluded that the Q-mass enhancement is composite.

2 data tables

No description provided.

No description provided.


Evidence for Structure in the 1+ State of the Q Region

The Aachen-Berlin-CERN-London-Vienna & Ecole Poly-Rutherford-Saclay collaborations Otter, G. ; Rudolph, G. ; Schmid, P. ; et al.
Nucl.Phys.B 106 (1976) 77-94, 1976.
Inspire Record 3373 DOI 10.17182/hepdata.35803

We have performed a partial-wave analysis of the mainly diffractively produced low-mass (K ππ ) system in the reactions K − p → K − π + π − p and K − p → K 0 π − π 0 p at 10, 14 and 16 GeV /c . We find that the dominant 1 + S ( K ∗ π ) state has possibly a two-peak structure (around 1.27 and 1.37 GeV). In contrast the 1 + S(K ϱ ) state shows one narrow peak near thershold (around 1.27 GeV). These states are found to be of different origin. The results favour the interpretation of the 1 + S(K ϱ ) as a 1 + resonance below the (K ϱ ) threshold. The t ′ pp dependence is found to be different for the 1 + and 0 − states.

2 data tables

No description provided.

No description provided.


Measurement of k*- production in the reaction k- p ---> k*- p

Blieden, H.R. ; Finocchiaro, G. ; Kirz, J. ; et al.
Phys.Lett.B 39 (1972) 668-670, 1972.
Inspire Record 75745 DOI 10.17182/hepdata.41300

The K ∗− spectrum in the reaction K − +p → K ∗− +p has been measured at beam momenta 10.9, 13.4 and 15.9 GeV/ c using the missing mass technique. Production of the L(1770), and a Q-K ∗ (1420) enhancement are observed. Differential cross sections in the range of momentum transfer 0.12 < | t pp | < 0.40 (GeV/ c ) 2 are given. The L meson is observed with a width Γ = 100 ± 26 MeV. The mass spectrum between the L and 2.5 GeV does not show significant structure.

2 data tables

No description provided.

No description provided.


Partial Wave Analysis of the (anti-K0 pi- pi0)-System Produced in the q-Mass Region in K- p --> (anti-K0 pi- pi0) p at 10-GeV/c and 16-GeV/c

The Aachen-Berlin-CERN-London-Vienna collaboration Otter, G. ; Barnham, Keith W J ; Cocconi, Vanna T ; et al.
Nucl.Phys.B 96 (1975) 29-44, 1975.
Inspire Record 98691 DOI 10.17182/hepdata.31971

A partial-wave analysis has been performed of the diffractively produced low-mass ( K ̄ 0 π − π 0 ) system in the reaction K − p → ( K ̄ 0 π − π 0 ) p at 10 and 16 GeV/ c . Thus information complementary to that derived from the K − p → (K − π + π − )p) channel is obtained. The presence of the K ϱ decay mode, besides the dominant K ∗ (890)π mode, for the state J P = 1 + , is confirmed. It is also confirmed that for this 1 + state the assumption of factorization of the amplitude into “production” and “decay” does not hold: the two decay modes K ∗ π and K ϱ have different polarisation properties (helicity is approximately conserved in the t -channel for the first, in the s -channel for the second). The assumption that the ( K ̄ 0 π − π 0 ) system has isospin I = 1 2 has been tested and found to hold. From the cross sections for the various J P states, assuming I = 1 2 , the cross sections for the (K − π + π − ) system are predicted and compared with the experimental ones. In general, agreement is found.

2 data tables

No description provided.

No description provided.


Partial Wave Analysis of the Q Region in the Reactions K- p --> K- pi+ pi- p and K- p --> anti-K0 pi- pi0 p at 14.3-GeV/c

Tovey, S.N. ; Hansen, J.D. ; Paler, K. ; et al.
Nucl.Phys.B 95 (1975) 109-129, 1975.
Inspire Record 2363 DOI 10.17182/hepdata.31975

We have studied the reactions K − p → K − π + π − p and K − p → K 0 π − π 0 p at 14.3 GeV/ c using respectively 15 992 and 3723 events. Partial-wave analysis of the region 1.0 < m (K ππ ) < 1.7 GeV have been made using a modified version of the method developed at the University of Illinois.

1 data table

No description provided.


Production Properties of Q Mesons in K+- p --> K+- pi+ pi- p at 13-GeV

Brandenburg, G.W. ; Carnegie, R.K. ; Cashmore, R.J. ; et al.
Phys.Rev.Lett. 36 (1976) 706, 1976.
Inspire Record 100755 DOI 10.17182/hepdata.21076

The momentum transfer (t′) dependence of the JP=1+K*π and ρK partial waves in the K±π+π− system is presented. The production of the Q1 meson (m∼1300 MeV), which has a large ρK decay mode, obeys approximate s-channel helicity conservation. In contrast the production of the Q2 meson (m∼1400 MeV), which decays predominantly to K*π, satisfies approximate t-channel helicity conservation. Furthermore the Q1 production distributions are virtually identical, whereas the Q2± distributions exhibit a distinct cross-over for |t′|∼0.18 GeV2.

1 data table

No description provided.


Some Three-Body Final States in K- p Reactions at 14.3-GeV/c

Wohl, C.G. ; Barloutaud, R. ; Borg, A. ; et al.
Nucl.Phys.B 132 (1978) 401-428, 1978.
Inspire Record 5385 DOI 10.17182/hepdata.35160

We present experimental results on a number of K − p reactions at 14.3 GeV/ c that have three bodies in the final state. The final states are K − ω p , K − π p , Λπ + π − , Λ K + K − , Λp p , K ∗ − ω p , Λ(1520) K + K − and Λ(1520) p p . Whenever, with one exception explained by the Zweig rule, there is a K − or a proton in the final state, there is a diffractive-like threshold enhancement in the mass spectrum of the two recoiling particles. These enhancements account for a large fraction of the events in all but the Λπ + π − final state, where they cannot occur, and which is dominated by resonance production. We find evidence for the Q 1 (1300) decaying into K − ω .

1 data table

THE DIFFRACTION DISSOCIATION CROSS SECTIONS ARE FOR DIFFRACTIVE THRESHOLD ENHANCEMENTS IN THE TWO-BODY MASS SPECTRA (WITHIN 500 MEV CM ENERGY OF THRESHOLD).