Date

Investigation of (K pi) Mass Enhancement Near 1870-MeV in the Reaction K- p --> K- pi+ n at 10-GeV/c and 16-GeV/c

The Aachen-Berlin-CERN-London-Vienna collaboration Grassler, H. ; Laven, H. ; Otter, G. ; et al.
Nucl.Phys.B 125 (1977) 189, 1977.
Inspire Record 119121 DOI 10.17182/hepdata.35408

An enhancement in the (K − π + ) mass distribution at 1871 ± 10 MeV with full width of 285 ± 40 MeV is observed in the charge-exchange reaction K − p → K − π + n at 10 and 16 GeV/ c . The energy dependence of its cross section, the shape of the differential cross section d σ /d t and the decay angular distributions are consistent with a production mechanism by pion exchange. No significant enhancement at the same mass is seen in the non-charge exchange reaction K − p → (K π ) − p. The experimental evidence is reviewed and it is suggested that there may be more than one K ∗ enhancement in the 1700–1900 mass region.

2 data tables

FOR ALL EVENTS WITH 1.7 < M(K- PI+) < 2 GEV. NO FORWARD DIP. 'THETA CUT'.

THE 14.3 GEV/C POINT IS FROM ANALYSING THE DATA OF M. SPIRO ET AL., PL 60B, 389 (1976) IN THE SAME WAY. 'THETA-CUT'.


K- p --> Lambda0 Or Sigma0 Vector Meson at 3.1-GeV/c-3.6-GeV/c

Lyons, L. ; Cooper-Sarkar, Amanda M. ; Clark, A.G. ;
Nucl.Phys.B 125 (1977) 207-242, 1977.
Inspire Record 125082 DOI 10.17182/hepdata.35373

We present data on the five final states Λω, Λφ, Λϱ 0 , Σ 0 ⊘ and Σ 0 ϱ 0 produced in 3.1–3.6 GeV/ c K − p interactions. These data are from a bubble chamber experiment with 18 events/μb. For all reactions the data consist of the overall and differetial cross sections, and the hyperon polarisation and the vector meson's density matrix elements as a function of momentum transfer. For Λω and Λ⊘, an almost complete amplitude analysis is performed in several regions of momentum transfer. The data are examined from the point of view of various exchange models.

15 data tables

CORRECTED FOR UNSEEN DECAY MODES OF LAMBDA, OMEGA AND PHI.

No description provided.

NO BACKWARD PHI PRODUCTION.

More…

$\pi^- p$ at 205 GeV/c: Multiplicities of Charged and Neutral Particles Production of Neutral Particles

Ljung, D. ; Bogert, D. ; Hanft, R. ; et al.
Phys.Rev.D 15 (1977) 3163, 1977.
Inspire Record 111665 DOI 10.17182/hepdata.24616

A study of 205-GeV/c π−p interactions has been made with a 48 800-picture exposure in the bare Fermilab 30-inch hydrogen bubble chamber. The average number of charged particles produced per inelastic interaction is 7.99±0.06. The elastic cross section is 3.18±0.13 mb and the total cross section is 24.19±0.44 mb. The inclusive cross sections for neutral-particle production are: σ(γ)=171.3±15.3 mb, σ(KS0)=3.64±0.61 mb (x<0.3), σ(Λ)=1.71±0.34 mb (x<0.3), and σ(Λ¯)=0.59±0.23 mb (x<0.1). The average number of π0's produced per inelastic collision is consistent with a linear rise with the number of charged particles, and about equal to the number of produced π− or π+. The average number of K0's, Λ's, and Λ¯'s is consistent with very little dependence on the number of charged particles. General characteristics of neutral-particle production are presented and compared with other experiments. For each topology the produced neutral energy is ∼13 of the incident energy.

8 data tables

No description provided.

No description provided.

No description provided.

More…

One, Two and Three Pion Production in p d Collisions at 19-GeV/c

The Scandinavian Bubble Chamber collaboration Bakken, V. ; Gennow, H. ; Jacobsen, T. ; et al.
Nucl.Phys.B 124 (1977) 229-254, 1977.
Inspire Record 111511 DOI 10.17182/hepdata.35429

We present cross sections for coherent and non-coherent production of one, two and three pions in pd reactions at 19 GeV/ c . The mass distributions of the two pion non-coherent channels are studied. Strong single Δ(1236) and also some double Δ production is observed. Clear evidence for ϱ production is seen.

1 data table

SLOPE FITTED FOR -TP = 0.00 TO 0.14 GEV**2.


Boson States in the Reaction pi- p --> pi- pi- pi+ p with Leading pi+ Meson at 25-GeV/c

The Serpukhov-CERN collaboration Antipov, Yu.M. ; Busnello, R. ; Damgaard, G. ; et al.
Nucl.Phys.B 119 (1977) 45-59, 1977.
Inspire Record 109772 DOI 10.17182/hepdata.35516

The reaction π − + p → π − + π − + π + + p at 25 GeV/ c was studied in the mass region M 3 π ⩾ 1.8 GeV with leading π + . The mass spectrum of the π + π − system shows peaks corresponding to the ϱ 0 , f and g 0 resonances and an enhancement around 1.9 GeV. Evidence is presented for a J P = 3 + s-wave g 0 π − state (A 4 ) similar to the ϱ 0 π − (A 1 ) and fπ − (A 3 ) threshold enhancements.

1 data table

No description provided.


$\pi^- p$ Interactions at 360-GeV/c: Measurement of the Total and Elastic Cross-Sections and the Charged Particle Multiplicity Distribution

Firestone, A. ; Anderson, E.W. ; Chang, V. ; et al.
Phys.Rev.D 14 (1976) 2902, 1976.
Inspire Record 3926 DOI 10.17182/hepdata.24670

In a sample of 108 563 pictures taken with the Fermilab 30-inch hydrogen bubble chamber, exposed to a 360-GeV/c π− beam, we have observed 19 453 interactions in a selected fiducial region. The observed charged multiplicity distribution has been corrected for the effects of scan efficiency, errors in prong count, missed close-in vees, secondary interactions, and neutron stars and for Dalitz pairs. The two-prong events have been corrected for losses at low −t. The total cross section is measured to be 25.25 ± 0.35 mb, and the elastic cross section is 3.61 ± 0.11 mb with an exponential slope of (8.82 ± 0.30) (GeV/c)−2. The average charged-particle multiplicity for inelastic events is 8.73 ± 0.04, and the second moment f2 is measured to be 9.83 ± 0.23.

2 data tables

SYSTEMATIC CORRECTIONS INCLUDED IN ERRORS.

FROM FIT, FORWARD D(SIG)/DT = 31.84 +- 0.68 MB/GEV**2, AND AGREES WITH OPTICAL POINT FROM MEASURED TOTAL CROSS SECTIONS.


Observation of the K* (1780) in the Reaction K+ p --> K0(s) pi+ p at 10-GeV/c

Baldi, R. ; Bohringer, T. ; Dorsaz, P.A. ; et al.
Phys.Lett.B 63 (1976) 344-348, 1976.
Inspire Record 115724 DOI 10.17182/hepdata.27636

An analysis of the Kπ-system in the mass region of the K ∗ (1780), based on a sample of 46000 K s o π + final states, is presented. Evidence for a relatively narrow width, τ ≈ 100 MeV, and for the spin parity assignment J P = 3 − is found.

1 data table

SLOPE DETERMINED WITHIN 0.2 < -T < 0.8 GEV**2 AND USED TO ESTIMATE TOTAL CROSS SECTION.


Spin Parity Structure of the (anti-K pi pi)0 System Produced in the Charge Exchange Reaction K- p --> (anti-K0 pi+ pi-) n at 4.2-GeV/c

The AMSTERDAM-CERN-NIJMEGEN-OXFORD collaboration Vergeest, J.S.M. ; Cerrada, M. ; Chaloupka, V. ; et al.
Phys.Lett.B 62 (1976) 471-476, 1976.
Inspire Record 114349 DOI 10.17182/hepdata.27652

A partial wave analysis of the K 0 π + π − system produced in the charge exchange reaction K − p → ( K 0 π + π − ) n at 4.2 GeV/ c has been performed both as a function of Kππ mass and of t ′. The 1 + S wave forms the largest contribution to the K ππ system and peaks at roughly the same mass as the Q in diffractive K ππ production. The polarization properties of the 1 + S ( K ∗ π) and 1 + S (Kϱ) waves differ fromt those of the diffractive 1 + wave. There is some evidence for a resonance contribution to 1 + S ( K ∗ π) . The strong 2 + wave the K ∗ (1420) and the K ϱ/ K ∗ ϱ decay branching ratio determined to be 0.36±0.10. An enhancement with spin-parity 1 − is observed under K ∗ (1420) .

2 data tables

CROSS SECTION CORRECTED FOR BREIT-WIGNER TAILS, THE TP CUT, UNSEEN <AK0 PI> AND <K RHO> DECAY MODES. BRANCHING RATIO K*(1420) --> <K RHO>/<K* PI> = 0.36 +- 0.10.

No description provided.


Cross-Sections and Charged Multiplicity Distributions for $\pi^- p$ and $K^- p$ Interactions at 147 GeV/c.

Fong, D. ; Heller, M. ; Shapiro, A.M. ; et al.
Nucl.Phys.B 102 (1976) 386-404, 1976.
Inspire Record 112604 DOI 10.17182/hepdata.36057

The results presented in this paper were obtained from a 105 000 frame exposure of the FNAL Hybrid Proportional Wire Chamber-30 inch Bubble Chamber System, in a tagged beam of 147 GeV/ c negative particles. Elastic, total and topological cross sections were obtained for both π − p and K − p interactions. Comparisons with other data, taken with various beam particles over large momentum intervals, show good agreement with KNO scaling, and similarity in the scaling behavior of σ n for the different beam particles.

3 data tables

THESE CROSS SECTIONS ARE NOT NORMALIZED TO ANY OTHER ABSOLUTE MEASUREMENT. THE ERRORS INCLUDE SOME SYSTEMATIC ERRORS.

THE FORWARD CROSS SECTION AGREES WELL WITH THE OPTICAL POINT FROM TOTAL CROSS SECTION MEASUREMENTS.

THESE CROSS SECTIONS ARE NOT NORMALIZED TO ANY OTHER ABSOLUTE MEASUREMENT.


Peripheral Behavior of anti-p p --> K*+- K-+ Between 1-GeV/c and 2.5-GeV/c

Baubillier, M. ; De Billy, L. ; Rivoal, M. ; et al.
Nucl.Phys.B 104 (1976) 277-289, 1976.
Inspire Record 113110 DOI 10.17182/hepdata.35964

The reaction p p → K ∗ K does not exhibit any s -channel resonance effect between 1 and 2.5 GeV/ c . On the contrary, the data on p p → K ∗∓ K ± are compatible with an exchange mechanism in the t - and u -channels above 1.5 GeV/ c . Strong similarities are found with p p → K − K + and K ∗− K ∗+ . The polarisation of K ∗± is given. The reaction p p → K ∗0 K 0 vanishes above 1.5 GeV/ c

7 data tables

No description provided.

LEG(L=0) = SIG/(4*PI).

LEG(L=0) = SIG/(4*PI).

More…