We have measured the differential cross section for pp and p̄p elastic scattering at √ s = 31, 53 and 62 GeV in the interval 0.05 < | t | < 0.85 GeV 2 at the CERN ISR using the Split Field Magnet detector. At 53 and 62 GeV, for 0.17 < | t | < 0.85 GeV 2 both pp and p̄p data show simple exponential behaviour in t ; at √ s = 31 GeV the data for 0.05 < | t | < 0.85 GeV 2 are consistent with a change in slope near | t | = 0.15 GeV 2 .
ERRORS CONTAIN BOTH STATISTICAL AND T-DEPENDENT SYSYEMATIC ERRORS.
No description provided.
LOCAL SLOPE PARAMETERS BASED ON QUADRATIC EXPONENTIAL FIT.
Results are presented on the charge exchange reaction\(\bar pp \to \bar nn\) and\(\bar np\) annihilations from bubble chamber exposures to antiproton beam of momenta 700 and 760 MeV/c. The differential cross section of\(\bar pp \to \bar nn\) shows a forward spike followed by a clear dip bump structure. Total annihilation cross section of\(\bar np\) for average\(\bar n\) momentum of 700 MeV/c has been evaluated to be 55.4±2.2 mb. The multiplicity, Feynmanx andpT2 distributions for inclusive charged pions in\(\bar pp\) and\(\bar np\) annihilations are found to be similar. The emission of charged pions from\(\bar np\) annihilations are found to be consistent with thermodynamic models with temperature ∼110 MeV.
No description provided.
No description provided.
No description provided.
Antiproton-proton elastic scattering was measured at c.m.s. energies √s =546 and 1800 GeV in the range of four-momentum transfer squared 0.025<-t<0.29 GeV2. The data are well described by the exponential form ebt with a slope b=15.28±0.58 (16.98±0.25) GeV−2 at √s =546 (1800) GeV. The elastic scattering cross sections are, respectively, σel=12.87±0.30 and 19.70±0.85 mb.
Final results (systematic errors included).
Final results (systematic errors included).
Statistical errors only. Data supplied by S. Belforte.
The pp differential elastic scattering cross section was measured at √s = 1800 GeV, using an improved accelerator luminositydetermination and CDF small angle data in the range of 0.05 ≤ t ≤ 0.2(GeV/c)2. By extrapolating the differential cross sections to t=0 and using the optical theorem we obtain a total cross section of σtot(pp) = 72.0±3.6 mb. This result is preliminary in the sense that we expect to further reduce the systematic error on the optical point.
No description provided.
Data on the reactions π − p → p π − , p p → π + π − , K − p → pK and p p → p p at 8 and 12 GeV/ c are presented. Our results agree with line reversal symmetry (between π − p → p π − and p p → π + π − ), Regge pole behaviour for non-exotic reactions ( π − p → p π − , p p → π + π − ), and universal behaviour for exotic reactions ( p p → p p , K − p → pK − ) with d σ /d u | u =0 ∼ s −10 excluding the existence of a “glory” mechanism in p p elastic backward scattering in our energy range.
No description provided.
No description provided.
No description provided.
The presence of a structure in the p̄p total cross section at 1930–1940 MeV, with a narrow width of 9 MeV is confirmed. The interpretation of the effect as a single, non interfering, resonance is made difficult by the comparison of the elastic scattering with the charge exchange cross sections.
'INELASTIC' IS 0+2+4+6 PRONGS MINUS ELASTIC.
We measured the differential cross section for p̄p and pp elastic scattering in the momentum-transfer range 0.01 <| t | < 1.0 GeV 2 at the CERN Intersecting Storage Rings with center-of-mass energy s = 52.8 GeV . Fitting the differential cross section with an exponential [ A exp ( bt )], we found b p p = 13.92 ± 0.59 GeV −2 for | t | < 0.05 GeV 2 , whilst for | t | > 0.09 GeV 2 , b p p = 10.68 ± 0.26 GeV −2 . Using the optical theorem, we obtained for the total cross section σ tot ( p p)= 44.86 ± 0.78 mb and, by integrating the differential cross section, we obtained for the total elastic cross section σ el ( p p) = 7.89 ± 0.28 mb . Calculations of σ tot combining elastic-rate and total-rate measurements are also given. All of these measurements were also performed for pp scattering at the same energy, and the results for both reactions are compared.
NUMERICAL VALUES OF DATA IN FIGURE TAKEN FROM PREPRINT CERN-EP/82-65.
NUMERICAL VALUES OF DATA ON FIGURES TAKEN FROM PREPRINT CERN-EP/82-65.
No description provided.
The general features of p p interactions at 32 GeV/ c are analysed in a bubble chamber experiment with a statistics of 5.2 μb/event. The inclusive production of neutral strange particles and pions is analysed and compared to results obtained at other energies and in pp interactions. Total cross sections are determined for various 4C reactions and the relative contributions of diffractive dissociation and Δ Δ production to the reaction p p → p p π + π − are estimated.
No description provided.
TOTAL CROSS SECTIONS FOR 4C REACTIONS.
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THESE DATA ARE TABULATED IN THE RECORD OF THE PUBLISHED VERSION.
DIVIDE BY 20 TO GET MB/GEV**2.
FROM QUADRATIC EXPONENTIAL FITS TO D(SIG)/DT FOR -T = 0 TO 1.4 GEV**2. SYSTEMATIC ERRORS INCLUDED.
We report the results of a study of the reaction p p → p + x at 32.1 GeV c , where the recoiling proton has a small laboratory momentum. The reaction is studied in the 4.5 m Mirabelle bubble chamber at Serpukhov. We compare the diffractive dissociation of the incident antiproton to other incident particles.
No description provided.
CALCULATED USING THE OPTICAL THEOREM AND THE TOTAL CROSS SECTION FOR AP P OF 46 +- 0.3 MB.
TOPOLOGICAL AND BEAM DIFFRACTION CROSS SECTIONS WITH PLAB(FINAL STATE PROTON) < 1.1 GEV/C.
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INTEGRATED D(SIG)/D(T).
OBTAINED FROM FIT D(SIG)/D(T)=A*EXP(B*T+C*T**2) IN 0.05 < -T < 0.3.
We report a measurement of the p p total cross section at √ s =1.8 TeV using a luminosity-independent method. Our result is σ T =72.1±3.3 mb ; we also derive the total elastic cross section σ el =16.6±1.6 mb. A value is obtained for the total single diffraction cross section of 11.7±2.3 mb.
No description provided.
Assuming RHO = 0.145.
No description provided.
We have measured the antiproton-proton total cross section at √s =1.8 TeV at the Fermilab Tevatron Collider; the value obtained is 78.3±5.9 mb. B, the nuclear slope parameter for elastic scattering, was measured to be 16.3±0.5 (GeV/c)−2. From these data, we derive a value for the total elastic cross section.
Nuclear Store Parameter.
Total cross section measurement. Errors contain systematic effects folded including a 15 PCT error in luminosity measurement which dominates the error.
Total cross section assuming RHO = 0.145 (low energy fit). If RHO is taken as 0.24 obtained by UA4 at sqrt(s) = 546 GeV, the value of SIG is reduced by 1.8 PCT.
We report a measurement of the p p ̄ total cross section at s =1.8 TeV at the Fermilab Tevatron Collider, using the luminosity independent method. Our result is σ T =71.71±2.02 mb. We also obtained values of the total elastic and total inelastic cross sections.
No description provided.
No description provided.
The differential cross sections for the elastic scattering of π+, π−, K+, K−, p, and p¯ on protons have been measured in the t interval -0.04 to -0.75 GeV2 at five momenta: 50, 70, 100, 140, and 175 GeV/c. The t distributions have been parametrized by the quadratic exponential form dσdt=Aexp(B|t|+C|t|2) and the energy dependence has been described in terms of a single-pole Regge model. The pp and K+p diffraction peaks are found to shrink with α′∼0.20 and ∼0.15 GeV−2, respectively. The p¯p diffraction peak is antishrinking while π±p and K−p are relatively energy-independent. Total elastic cross sections are calculated by integrating the differential cross sections. The rapid decline in σel observed at low energies has stopped and all six reactions approach relatively constant values of σel. The ratio of σelσtot approaches a constant value for all six reactions by 100 GeV, consistent with the predictions of the geometric-scaling hypothesis. This ratio is ∼0.18 for pp and p¯p, and ∼0.12-0.14 for π±p and K±p. A crossover is observed between K+p and K−p scattering at |t|∼0.19 GeV2, and between pp and p¯p at |t|∼0.11 GeV2. Inversion of the cross sections into impact-parameter space shows that protons are quite transparent to mesons even in head-on collisions. The probability for a meson to pass through a proton head-on without interaction inelastically is ∼20% while it is only ∼6% for an incident proton or antiproton. Finally, the results are compared with various quark-model predictions.
No description provided.
No description provided.
No description provided.
Topological and channel cross sections are given for annihilation and inelastic final states produced in p p interactions at 9.1 GeV/c. Cross sections for prominent resonances in specific channels and charged pion, ϱ 0 and Δ ++ inclusive cross sections are also presented.
No description provided.
FITTED FORWARD D(SIG)/DT = 153 +- 8 MB/GEV**2.
CHANNEL CROSS SECTIONS FOR 2, 4, 6, AND 8 PRONG REACTIONS.
Proton-antiproton elastic scattering at CM energy 540 GeV has been studied in the t -range 0.04 < − t < 0.45 GeV 2 . The data are well fitted by the form exp ( bt ) with b = 17.1 ± 1.0 GeV −2 for | t | = 0.04 − 0.18 GeV su 2 and b = 13.7 ± 0.2 ± 0.2 GeV −2 for | t | = 0.21−0.45 GeV 2 . A luminosity measurement combined with the optical theorem gives σ tot = 67.6 ± 5.9 ± 2.7 mb and σ e1 / σ tot = 0.209 ± 0.018 ± 0.008.
No description provided.
No description provided.
ELASTIC RATIO ASSUMES RHO=0.
The proton-antiproton total cross section was measured at the CM energy √s = 546 GeV . The result is σ tot = 61.9± 1.5 mb . The ratio of the elastic to the total cross section is σ e ℓ / σ tot = 0.215±0.005. A comparison to the lower energy data shows that the increase of the total cross section with energy is very close to a log 2 s behaviour.
CROSS SECTIONS ASSUMING RHO = 0.15.
RATIO OF ELASTIC TO TOTAL CROSS SECTION.
The proton-antiproton total cross section was measured at the center-of-mass energy of s = 541 GeV at the S p pS at CERN using a luminosity dependent method. The result σ tot =63.0±2.1 mb is in agreement with the luminosity independent measurement performed earlier by the UA4 Collaboration.
No description provided.
No description provided.
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No description provided.
We report a study of 20 exclusive reactions measured at the AGS at 5.9 GeV/c incident momentum, 90° center of mass. This experiment confirms the strong quark flow dependence of two-body hadron-hadron scattering at large angle. At 9.9 GeV/c an upper limit had been set for the ratio of cross sections for (p¯p→p¯p)(pp→pp) at 90° c.m., with the ratio less than 4%. The present experiment was performed at lower energy to gain sensitivity, but was still within the fixed angle scaling region. A ratio R(p¯ppp)≈140 was measured at 5.9 GeV/c, 90° c.m. in comparison to a ratio near 1.7 for small angle scattering. In addition, many other reactions were measured, often for the first time at 90° c.m. in the scaling region, using beams of π±, K±, p, and p¯ on a hydrogen target. There are similar large differences in cross sections for other reactions: R(K−p→π+Σ−K−p→π−Σ+)≈112, for example. The relative magnitudes of the different cross sections are consistent with the dominance of quark interchange in these 90° reactions, and indicate that pure gluon exchange and quark-antiquark annihilation diagrams are much less important. The angular dependence of several elastic cross sections and the energy dependence at a fixed angle of many of the reactions are also presented.
Cross sections at 90 degrees in the centre-of-mass.
No description provided.
No description provided.
The interaction between antiprotons and protons has been studied in the range 1910 to 1990 MeV center-of-mass energy in a drift-chamber experiment at the Brookhaven Alternating Gradient Synchrotron. The total cross section has been determined at eleven different incident momenta, and the elastic cross section between 8 and 30 deg in the laboratory has been measured with an energy resolution of about 5 MeV. The cross section for annihilation into charged mesons has also been measured, with the same resolution. There is no evidence in any of these channels for the existence of a narrow resonance.
Data are for total sample with nuclear physics calculation as described in the paper.
Partial elastic cross sections.
Partial annihilation cross sections.
Antiproton-proton total elastic cross sections at 21 incident momenta in the range 0.69 to 2.43 GeV/ c have been deduced by combining p̄p elastic differential cross sections over a c.m. angular range −0.95 ⩽ cos θ ∗ ⩽ 0.93 with forward elastic cross sections derived from recent real-part measurements and p̄p total cross sections. Two bumps are observed, at M 1 ⋍ 2.155 and M 2 ⋍ 2.345 GeV /c 2 , having widths of Г 1 ∼ 0.135 and Г 2 ∼ 0.135 GeV /c 2 . Corresponding structures in other p̄p reaction channels are discussed.
Axis error includes +- 4/4 contribution.
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The cross section for the reaction PBAR P --> INELASTIC comprises pion production without annihilation and without strange particle production.
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