Data on 6.2 GeV/ c π − p and K − p elastic scattering cross sections are presented in the range 0.3 < − t < 10.7 (GeV/ c ) 2 .
No description provided.
No description provided.
The differential cross section for π+p elastic scattering has been measured at 13.8 GeVc for 0.7<|t|<3.8(GeVc)2. The cross section is found to be equal to that previously obtained for π−p elastic scattering, except in the region |t|=2.8 (GeVc)2, where the π+p data do not show the prominent dip observed in π−p scattering. Data have also been obtained for 13.8−GeVc K+p elastic scattering for 0.8<|t|<2.2 (GeVc)2.
No description provided.
No description provided.
Data are presented on elastic πp and Kp scattering for values of −t up to 2.5 and 3.5 (GeV/c)2 at incident momenta of 100 and 200 GeV/c, respectively. All of the cross sections are found to be nearly identical, although there is some momentum dependence of the π+p data; a small systematic difference observed between pion and kaon data cannot be explained by geometrical scaling.
No description provided.
We present results of measurements of the differential cross sections for the following elastic-scattering reactions: (i) π + p at 5.2 and 7.0 GeV/ c in the range −1 < u < 0.02 (GeV/ c ) 2 , (ii) π − p at 7.0 GeV/ c in the range −0.7 < u < 0.05 (GeV/ c ) 2 , (iii) K + p at 5.2 and 7.0 GeV/ c in the ranges −1 < t < −0.01 (GeV/ c ) 2 and −1 < u < 0 (GeV/ c ) 2 , and K − p at 7.0 GeV/ c in the range −1 < u < 0 (GeV/ c ) 2 .
No description provided.
No description provided.
SIDE GEOMETRY.
The differential cross sections for π + p elastic scattering at0.6, 1.0, 1.5, 2.0, GeV/ c for π - p at 1.0, 1.5, 2.0 GeV/ c , for K - p at 1.2, 1.8, 2.6 GeV/ c and for K - p at 0.9, 1.2, 1.4, 1.6, 1.8, 2.6 GeV/ c have been measured with an overall accuracy ofthe order of 1 to 2% in an electronics experiment over the angular region corresponding to momentum transfer t between 0.0005 and 0.10 GeV 2 . Making use of the interference effects between the Coulomb and the nuclear interaction, we have determined the magnitude and sign of the real part of the scattering amplitude near t = 0. The K ± p real parts have been used in a dispersion relation to derive the value of the KNΛ coupling constant.
'TABLE'. 'BIN'.
'TABLE'. 'BIN'.
'TABLE'. 'BIN'.
Angular distributions of π + and K + p elastic scattering have been measured for an incident beam momentum of 10.0 GeV/ c . For π + p elastic scattering almost the complete angular distribution was measured. The angular distribution of proton-proton elastic scattering was measured for an incident momentum of 9.0 GeV/ c in the interval of the four-momentum transfer squared from 0.7 (GeV/ c ) 2 to 5.0 (GeV/ v ) 2 . For π + p elastic scattering the structures at − t = 2.8 (GeV/ c ) 2 and − t = 4.8 (GeV/ c ) 2 are less pronounced than at lower momenta. The cross section for scattering at 90° in the c.m. system is of the order of 1 nb/GeV/ c ) 2 . For K + p elastic scattering is a break in the angular distribution around − t = 3 (GeV/ c ) 2 . The differential cross sections for proton-proton elastic scattering decrease smoothly with increasing momentum transfers.
S=19.667 GEV**2, U=-T-17.867 GEV**2.
S=19.91 GEV**2, U=-T-17.704 GEV**2.
S=18.74 GEV**2.
None
No description provided.
No description provided.
FROM EXPONENTIAL FIT OF D(SIG)/D(T) IN RANGE 0. < ABS(T) < 1. GEV.
The K − p differential and total elastic cross-sections have been measured at 14.25 GeV/ c . The results have been compared with various Regge models.
No description provided.
None
No description provided.
No description provided.
No description provided.
Differential cross sections for π − p and pp elastic scattering have been measured at incident momenta ranging from 30 to 345 GeV and in the t range 0.002 (GeV/ c ) 2 ⩽ | t | ⩽ 0.04 (GeV/ c ) 2 . From the analysis of the data, the ratio ϱ ( t = 0) of the real to the imaginary parts of the forward scattering amplitude was determined together with the logarithmic slope b of the diffraction cone.
No description provided.
No description provided.
No description provided.
We have measured π±p and pp elastic differential cross sections in the range |cosθc.m.|<0.35 for incident momenta from 2 to 9.7 GeV/c for π−p and pp and from 2 to 6.3 GeV/c for π+p. We find that the fixed-c.m.-angle πp differential cross sections cannot be described as simple functions of s. The data are compared to the energy and angular dependence predicted by the constituent model of Gunion, Brodsky, and Blankenbecler.
No description provided.
No description provided.
No description provided.
A comprehensive measurement of the differential cross section for π±p and pp elastic scattering has been made at large center-of-mass angles. π−p and pp scattering were measured with incident laboratory momenta ranging from 2 to 9.5 GeV/c. π+p scattering was measured with momenta from 2 to 6.3 GeV/c. Scattering angles were in the range −0.3≲cosθc.m.≲0.4. The results of the experiment are compared to constituent models and statistical models.
No description provided.
The differential cross sections for elastic π − p, K − p , p p and π + p, pp scattering at 39 and 44.5 GeV/ c , respectively, have been measured in the interval of momentum transfer squared 0.15 ≤ ovbt | ≤ 2 (GeV/ c ) 2 .
No description provided.
No description provided.
No description provided.
Differential cross sections in the t -range between 0.02 and 1.5 GeV 2 have been measured for the elastic scattering of particles and antiparticles on protons at 6.4, 10.4 and 14 GeV for K ± p and 10.4 GeV for π ± p and p ± p . Large statistics have been achieved and systematic uncertainties have been minimized. The relative systematic uncertainty between particle and antiparticle data is less than 0.5%. Accurate measurements of the position of the first crossover between particle and antiparticle differential cross sections have been performed. As the energy increases from 6.4 to 14 GeV the K ± p crossover moves to smaller values by 0.010 GeV 2 with a statistical error of 0.006 GeV 2 and a systematic uncertainty of 0.005 GeV 2 . The crossover positions at 10.4 GeV for π ± , K ± and p ± scale approximately with the interaction radii.
CROSSOVER POSITION IS -T = 0.209 +- 0.004 (DSYS = 0.003) GEV**2.
CROSSOVER POSITION IS -T = 0.209 +- 0.004 (DSYS = 0.003) GEV**2. SMALL ANGLE CROSS SECTIONS IN SMALLER T-BINS.
CROSSOVER POSITION IS -T = 0.211 +- 0.004 (DSYS = 0.0025) GEV**2.
The differential cross section for π±, K±, and p± on hydrogen have been measured in the range 0.07<−t<1.6 (GeV/c)2. The dependence on momentum, momentum, transfer, and particle type are discussed.
No description provided.
Results are presented on π±p, K±p, and p±p elastic scattering measured with an apparatus having acceptance of 0.5<−t<2.5 (GeV/c)2 and 0.9<−t<11 (GeV/c)2 at 100 and 200 GeV/c, respectively. A diffractionlike dip is seen for the first time in the π−p t distribution at −t=4 (GeV/c)2. All meson-proton cross sections are found to be similar in the range 1<−t<2.5 (GeV/c)2, although some small systematic differences are observed. Cross sections for pp and p―p are compared with previous data.
No description provided.
No description provided.
No description provided.
Differential cross sections for π±p, K±p, pp, and p¯p elastic scattering were measured at 3, 3.65, 5, and 6 GeVc for momentum transfers from 0.03 to 1.5 GeV2 using the Argonne effective mass spectrometer. Particular attention was paid to the relative particle-antiparticle normalization. The crossover points are consistent with no energy dependence, average values being 0.14 ± 0.03, 1.190 ± 0.005, and 0.160 ± 0.007 GeV2 for π's, K's, and protons, respectively.
No description provided.
We report on a measurement of elastic differential cross sections for p±p, π±p, and K±p at 100 and 200 GeV/c in the range 0.03<|t|<0.10 (GeV/c)2. Our data display a simple exponential dependence which is consistent with other measurements in this t region or with extrapolations from higher t.
No description provided.
No description provided.
Results are presented from experiment WA7 at the CERN SPS, which has measured the elastic differential cross sections of π ± p, K ± p, p p and pp at incident momen ta of 20, 30 and 50 GeV/ c . The measurements cover the momentum transfer range 0.5 < | t | < 8 (GeV/ c ) 2 , corresponding to c.m. scattering angles between 10° and 50°. The experimental set-up, trigger logic and data analysis are described. The experimental results are compared with existing meson-proton and nucleon-proton data at lower and higher energies covering the medium- and large-| t | region. Some prominent models and their predictions for elastic scattering at WA7 energies and beyond are reviewed, with emphasis on geometrical scaling, factorizing eikonal models, lowest-order QCD and other dynamical exchange-type models. Results for p p two-body annihilation into π − π + and K − K + at 30 and 50 GeV/ c , obtained in parallel with the elastic p p data, are also presented.
No description provided.
No description provided.
No description provided.
Cross sections or upper limits are reported for 12 meson-baryon and two baryon-baryon reactions for an incident momentum of 9.9 GeV/c, near 90° c.m.: π±p→pπ±,pp±,π+°±,K+Σ±, (Λ0/Σ0)K0; K±p→pK±; p±p→pp. By studying the flavor dependence of the different reactions, we have been able to isolate the quark-interchange mechanism as dominant over gluon exchange and quark-antiquark annihilation.
No description provided.
No description provided.
Differential cross sections for elastic π±−p scattering have been measured at lab momenta of 8 and 12 GeV/c in a momentum-transfer region corresponding to 1.2≤−t≤6 (GeV/c)2. Also, differential cross sections near 180° were measured for 4 and 8 GeV/c pions. At momentum transfers greater than −t=2 (GeV/c)2, the π−p cross sections drop much faster with increasing angle than the corresponding p−p cross sections. Also, in the region −t≃1.3 (GeV/c)2, there is structure in the π−p angular distribution but not in the p−p angular distribution. At −t≃3 (GeV/c)2, the drop in cross section appears to stop and from then on the angular distribution is consistent with isotropy. But in the angular region 170° to 180°, the cross sections have become much larger, and sharp backward peaks are observed. Information is given on the energy and charge dependences and widths of these backward peaks.
'1'. '2'.
'1'. '2'.
No description provided.
Results are presented on π + p and K + p elastic scattering at 250 GeV/ c , the highest momentum so far reached for positive meson beams. The experiment (NA22) was performed with the european hybrid spectrometer. The π + p elastic cross section stays constant with energy while the K + p cross section increases.
No description provided.
No description provided.
ERRORS IN ELASTIC CROSS SECTIONS INCLUDE SYSTEMATIC ERRORS.
Results are presented of a wire-spark-chamber spectrometer measurement of the differential cross section for π−p elastic scattering at 14.15 GeV/c. The region covered in the square of the four-momentum transfer, t, is 0.01<−t<0.78 (GeV/c)2. The cross section is found to obey very nearly a simple exponential t dependence with no evidence of structure. A fit to the data of the form dσdt∝exp(bt+ct2) on the range 0.05<−t<0.78 (GeV/c)2 (i.e., above the region affected by Coulomb scattering) yields b=8.26±0.10 (GeV/c)2 and c=1.01±0.17 (GeV/c)−4. Considering the results of previous measurements, b≃11 (GeV/c)−2 for −t<0.05 (GeV/c)2, a deviation from the simple exponential near −t≃0.05 (GeV/c)2 is indicated.
No description provided.
The differential cross section for elastic scattering of 3.63−GeVc π− mesons on protons was studied with a hydrogen bubble chamber, the emphasis being on large-angle scattering. From 90 to 180° in the barycentric system, the cross section is roughly flat with an average value of 2.7±1.0 μb/sr. Near and at 180°, there may be a slight peak of magnitude 10±6 μb/sr. But if such a peak exists, it is only one-third to one-fourth the size of the 180° peak found in 4.0 GeVc π++p elastic scattering. In addition to comparison with other π−+p and π++p large-angle elastic-scattering measurements, this measurement is compared with large-angle p+p elastic scattering. In the forward hemisphere a small peak or a plateau exists at cos θ*=+0.60. This appears to be a second diffraction maximum such as has been found in lower-energy π+p elastic scattering. A survey of indications of such a second diffraction maximum in other π+p measurements shows that it always occurs in the vicinity of −t=1.2 (GeVc)2, where t is the square of the four-momentum transfer. As the incident momentum increases, the relative size of this second maximum decreases.
No description provided.
No description provided.
The elastic scattering of 3.55 GeV/ c π + and π − mesons by protons was measured at centre-of-mass angles between 165° and 177°. The angular distributions for 864 events show a steeply rising backward peak for π + p, while the shape is less clear for π − p.
No description provided.
No description provided.
Extrapolations.
Elastic cross-section measurements are presented for π ± −p at 20 GeV/ c and π − −p at 30 GeV/ c incident momenta in the large angle region (50° to 90° in the c.m. system). The data are compared with published lower energy elastic cross sections. A test is made of the dimensional counting rules for π ± −p elastic scattering and some indication of a deviation from this rule is observed in the π − −p case. A comparison is also made with the predictions of the constituent interchange model. Although the broad features of the predictions are confirmed, there are some important discrepancies. Finally, the predictions of the model due to Preparata and Soffer are also compared with the new data.
No description provided.
THE UPPER LIMIT QUOTED WHEN NO EVENTS OBSERVED IS THE CROSS SECTION CORRESPONDING TO ONE DETECTED EVENT.
THE UPPER LIMIT QUOTED WHEN NO EVENTS OBSERVED IS THE CROSS SECTION CORRESPONDING TO ONE DETECTED EVENT.
Elastic Σ − p and π − p cross section have been measured at 17.2 GeV/ c in the t interval −0.12, −0.38 (GeV/ c ) 2 . The Σ − p slope is b = 8.12 ± 0.35 (GeV/ c ) −2 .
No description provided.
We have measured small angle elastic pion-proton scattering in 40 and 50 GeV c π − beams at Serpukhov. Analysis of the data in the Coulomb interference region yields a value for the ratio of the real to the imaginary part of the strong amplitude, ϱ (0)=−0.074 ± 0.033 at 40 GeV/ c and ϱ (0)=−0.006 ±0.026 at 50 GeV/ c
STATISTICAL ERRORS ONLY.
STATISTICAL ERRORS ONLY.
Forward differential cross sections for π − p elastic scattering at 1.0, 1.5 and 2.0 GeV/ c show that the square of the imaginary parts of the nuclear scattering agrees with the optical theorem prediction within ±3%, when averaged over the three momenta.
No description provided.
The angular distribution of π + p elastic scattering has been measured at an incident momentum of 10 GeV/ c . Nearly the whole angular range was covered in one experimental set-up. The pronounced dip at − t = 2.8 (GeV/ c ) 2 , observed at lower momenta, has diminished and is essentially a shoulder at 10 GeV/ c . The other structure at larger momentum transfers are also different in detail from what we observed at 5 GeV/ c . In the 90° c.m. region the differential cross-section is approximately one nb/(GeV/ c ) 2 , which is more than two orders of magnitude lower than at 5 GeV/ c .
THESE DATA ARE REPORTED MORE FULLY IN C. BAGLIN ET AL., NP B98, 365 (1975).
We have measured elastic pion-proton scattering in a 50 GeV/ c π − beam at the 76 GeV proton synchrotron in Serpukhov. Data are presented for four-momenta transfer squared in the range 0.03 < t < 0.4 (GeV/ c ) 2 .
SLOPE IS 9.1, +0.2, -0.4 GEV**-2 (INCLUDING SYSTEMATIC ERRORS).
We present results from a measurement of the differential cross sections for Σ−p, Ξ−p, and π−p elastic scattering at 23 GeV/c. We have collected samples of 6200 Σ−p events, 67 Ξ−p events, and 30 000 π−p events in the interval 0.10<|t|<0.23 (GeV/c)2.
No description provided.
The differential cross section of π+p elastic scattering has been measured in two high-statistics bubble-chamber exposures at laboratory beam momenta of 3.7 and 7.1 GeV/c. A new feature suggested by these data is a dip in dσdu at −u≃3 GeV2. This dip corresponds well to the third zero of J0(b−u′), where ℏcb=1 fm. The effective u-channel Regge trajectory computed for these two energies has a slope of 0.22 ± 0.26.
No description provided.
None
No description provided.
REAL/IMAG OF FORWARD AMPLITUDE FROM FIT TO D(SIG)/DT.
None
No description provided.
No description provided.
IM(AMP) VIA OPTICAL THEOREM FROM TOTAL CROSS SECTIONS OF L. M. VASILYEV ET AL., PL 36B, 528 (1971).
The differential cross section for π−−p elastic scattering has been measured at 13.8 and 22.6 GeV/c up to −t=5 (GeV/c)2. The dips in the angular distribution at −t≈0.8 and 2.8 (GeV/c)2 previously observed at lower momenta become less prominent at higher momentum. The −t=2.8 (GeV/c)2 dip is still observed at 13.8 GeV/c, but at 22.6 GeV/c it has become a sharp kink in the angular distribution. At large momentum transfers, dσdt at fixed t is still decreasing with increasing s, but at a slower rate in the 14- to 23-GeV/c region than at lower momenta.
No description provided.
No description provided.
Results are presented on the measurement of 200-GeV/c π−p elastic scattering at −t from 0.8 to 11 (GeV/c)2. As −t is increased, dσdt falls by ∼6 decades to a prominent dip at 4 (GeV/c)2, followed by a second maximum and than a slow decrease with increasing −t.
No description provided.
Angular distributions for π+p→π+p were measured for 13 incident-pion momenta from 4.4 to 6.0 GeV/c and for −t less than ∼0.1 (GeV/c)2. This experiment was performed at the Zero Gradient Synchrotron of Argonne National Laboratory, where a focusing magnetic spectrometer and a scintillation-counter hodoscope were used. In fitting the angular distributions the strong-interaction contribution was parameterized by an exponential form exp(bt); the Coulomb interference was also included. The resulting values of the slope parameter for |t|<∼0.1 (GeV/c)2 are presented for each incident beam momentum.
ENLARGED GRAPHS OF FIGURES SUPPLIED BY J. A. POIRIER.
SLOPE IS FROM FITTING EXP(SLOPE*T) TO FORWARD DIFFERENTIAL CROSS SECTION FOR -T < 0.1 GEV**2 APPROX AFTER ALLOWING FOR COULOMB INTERACTION.
We have measured the differential cross section for π − p elastic scattering at eight incident momenta, 2.06, 2.26, 2.45, 2.65, 2.86, 3.05, 3.26 and 3.48 GeV/ c , in a wide range of c.m. scattering angle between 15° and 160°. A pronounced dip-bump structure has been found at large angles. Details of the structure are quantitatively described as functions of the incident momentum.
No description provided.
No description provided.
No description provided.
Measurements of the differential elastic cross sections for π − p scattering at incident momenta of 20 and 50 GeV c and π + p at 50 GeV c in the momentum transfer range 0.7 < |t|; < 8.0 ( GeV c ) 2 are presented. The data are compared with various models of elastic scattering.
No description provided.
No description provided.
No description provided.
Large-angle π±p elastic-scattering cross sections, measured between 2 and 9 GeV/c in fine intervals of incident momentum and scattering angle, are used to search for cross-section fluctuations occurring for small changes in the center-of-mass energy as suggested by Ericson and Mayer-Kuckuck and by Frautschi. Significant fluctuations are observed.
No description provided.
No description provided.
No description provided.
A description is given of an experiment to study elastic scattering of π ± , K ± and p on protons at c.m. scattering angles from 45° to 100° at incident laboratory momenta 20 GeV/ c and 30 GeV/ c . The corresponding t range is from −6.2 (GeV/ c ) 2 to −28 (GeV/ c ) 2 . There are no previous observations for these reactions in this t range. High intensity and large geometrical acceptance were required in order to measure the low cross sections. The experiment used a double-arm spectrometer. MWPCs were used for reconstruction, and threshold and differential Čerenkov counters for identification. Scintillation counters, Čerenkov counters and a hadron calorimeter were used in the trigger. The trigger logic utilized specially designed matrices and a hard wired microprocessor. The π − p elastic scattering cross sections follow approximately the dimensional counting rule from 3.5 GeV/ c .and up to 30 GeV/ c . The cross sections decrease by seven orders of magnitude in this energy range. The data is compared to quark models. None of these models give a comprehensive description of the results. However, some modifications to these models improve their consistency with the data.
EARLIER RESULTS GIVEN IN 'A'.
No description provided.
EARLIER RESULTS GIVEN IN 'A'.
We present results of measurements of K ± p and p p elastic scattering and of the annihilation reactions p p →π + π − and p p → K + K − at an incident laboratory momentum of 5 GeV/ c . Nearly complete angular distributions were obtained. Results are also presented for π -meson proton elastic scattering in the momentum transfer ranges 2 < − t < 8 (GeV/ c ) 2 (for π + ) and 0.16 < − t < 7 (GeV/ c ) 2 (for π − ). All measurements were done in one experimental geometry. The measured differential cross sections range from 10 to 10 −5 mb/(GeV/ c ) 2 .
-U = T + 8.486 GEV**2.
THE DATA FOR -T = 7.31 TO 8.45 GEV**2 WERE NORMALIZED TO OTHER EXPERIMENTS.
-U = T + 8.304 GEV**2.
None
No description provided.
No description provided.
No description provided.
The exclusive process π−p→ρ−p has been measured at 90° c.m. with an incident pion momentum of 9.9 GeV/c. We present data on the angular dependence of the decay ρ−→π−π0. We observe a strong azimuthal dependence in the decay in the c.m. helicity frame of the ρ. Such an azimuthal dependence is not compatible with SU(6) valence-quark perturbation calculations.
No description provided.
Differential cross sections have been measured for p¯p→π−π+ (1) and its line-reversed partner π+p→pπ+ (2) in the range tmin>t>−1.5 (GeV/c)2 at 6 GeV/c. Clear structure is seen in the differential cross section for Reaction (1) at t∼−0.4 (GeV/c)2. However, this feature is quite different from the striking dip seen in (2) at t∼−0.15 (GeV/c)2, indicating a failure of line reversal and disagreement with simple Regge models.
No description provided.
The differential cross-section for 5 GeV/ cπ + p and π − p elastic scattering have been measured in the c.m. angular region 27° < θ cm < 130° corresponding to 0.5 < | t | < 7.8 (GeV/ c ) 2 . Dips are observed in both reactions at − t = 2.8 and 4.8 (GeV/ c ) 2 where the cross-sections are approximately 0.1 μ b/(GeV/ c ) 2 .
No description provided.
Elastic scattering of 32.1 GeV/ c K + on protons has been measured in a bubble chamber experiment. Results are presented in the momentum transfer interval 0.06–1.40 GeV 2 and compared with data at different energies. An effective Regge trajectory is calculated using K + p elastic data from 10 to 175 GeV/ c .
No description provided.
The differential cross section for K ± p elastic scattering has been measured in the forward meson direction (0.0008 < t < 0.1 GeV 2 ) in an electronics experiment at incident momenta between 0.9 and 2.06 GeV/ c . The high statistics and absolute normalisation of the data allow a good determination of the real part of the forward nuclear scattering amplitude by means of the Coulomb-nuclear interference effect.
No description provided.
K + p elastic scattering has been measured over nearly the whole angular range at an incident momentum of 10 GeV/ c . The differential cross-section is found to decrease smoothly in the forward direction to - t ≈ 2 (GeV/ c ) 2 , where there is a change in slope, followed by a further decrease to - t ≈ 6 (GeV/ c ) 2 . Around 90° c.m. the cross-section is approximately 1 nb/(GeV/ c ) 2 , which is more than two orders of magnitude lower than at 5 GeV/ c . The backward peak has no structure.
THESE DATA ARE REPORTED MORE FULLY IN C. BAGLIN ET AL., NP B98, 365 (1975).