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.
We have measured the ratio of the real to the imaginary parts of the p¯p forward-scattering amplitude in the incident-momentum range 360 to 650 MeV/c. These results are in good agreement with predictions of the Paris nucleon-antinucleon potential model which include spin-flip effects.
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RESULTS OF FITS TO THE FORWARD-SCATTERING DIFFERENTIAL CROSS SECTIONS ASSUMING THE RATIO OF THE SPIN-FLIP TO NON-SPIN-FLIP PARTS OF THE FORWARD AMPLITUDE IS ZERO.
RESULTS OF FITS TO THE FORWARD-SCATTERING DIFFERENTIAL CROSS SECTIONS ASSUMING THE RATIO OF THE SPIN-FLIP TO NON-SPIN-FLIP PARTS OF THE FORWARD AMPLITUDE IS PARAMATERISED AS 0.3698-0.1384*PLAB(IN GEV).
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.
3roton-antiproton elastic scattering at cm energy 540 GeV has been studied in the t range 0.14 ⩽ − t ⩽ 0.26 GeV 2 . The data is well fitted by an exponential form exp( bt ) with b = 13.3 ± 1.5 GeV −2 .
Elastic Differentiaol Cross Section (545 events). DATA REQUESTED 21 FEB 1983. Data read from plot in paper (29 JAN 2015).
No description provided.
We present a measurement of the elastic differential cross section $d\sigma(p\bar{p}\rightarrow p\bar{p})/dt$ as a function of the four-momentum-transfer squared t. The data sample corresponds to an integrated luminosity of $\approx 31 nb^{-1}$ collected with the D0 detector using dedicated Tevatron $p\bar{p} $ Collider operating conditions at sqrt(s) = 1.96 TeV and covers the range $0.26 <|t|< 1.2 GeV^2$. For $|t|<0.6 GeV^2$, d\sigma/dt is described by an exponential function of the form $Ae^{-b|t|}$ with a slope parameter $ b = 16.86 \pm 0.10(stat) \pm 0.20(syst) GeV^{-2}$. A change in slope is observed at $|t| \approx 0.6 GeV^2$, followed by a more gradual |t| dependence with increasing values of |t|.
The $d\sigma$/$dt$ differential cross section. The statistical and systematic uncertainties are added in quadrature.
We report final results on the polarization parameter P in elastic scattering of π − , K − and antiprotons at 40 GeV/ c incident momentum. The energy dependence of P (t) in π − p above 10 GeV/ c is well fitted by P (t) α s αR(t)-α P (t) where α R (t) are the effective Regge and Pomeron trajectories respectively. The data in K − p are compatible with exchange degeneracy. The results inp¯p show an important structure for |t|> 0.3 (GeV/c) 2 demonstrating the existence of a large helicity flip amplitude.
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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.
Differential cross sections for p p elastic scattering have been measured for very small momentum transfers at six different incident antiproton momenta in the range 3.7 to 6.2 GeV/c by the detection of recoil protons at scattering angles close to 90°. Forward scattering parameters σ T , b , and ϱ have been determined. For the ϱ-parameter, up to an order of magnitude higher level of precision has been achieved compared to that in earlier experiments. It is found that existing dispersion theory predictions are in disagreement with our results for the ϱ-parameter.
Results of the SIG(T)-free analysis. Errors include systematic uncertainties.
Results of the SIG(T)-fixed analysis. Errors include systematic uncertainties.
CT values of the total cross section from the SIG(T)-free analysis. Errors include systematic uncertainties.
The antiproton-proton small-angle elastic-scattering distribution was measured at\(\sqrt s \) GeV at the Fermilab Tevatron Collider. A fit to the nuclear-scattering distribution in the range 0.065≤|t|≤0.21 (GeV/c)2 givesb=(16.2±0.5±0.5) (GeV/c)−2 for the logarithmic slope parameter. Using the optical theorem and the luminosity from Collider parameters, we obtain σtoto(1+ρ2)1/2 =(61.7±3.7±4.4)mb.
No description provided.
Cross sections derived assuming RE(AMP)/IM(AMP) = 0.140, see Phys. Lett. B188, 143 (1987).
Slope was derived in the t range -0.065 < t < -0.21 (GeV/c)**2.
We have measured ρ, the ratio of the real to the imaginary part of the p¯p forward elastic-scattering amplitude, at √s =1.8 TeV. Our result, ρ=0.140±0.069, is compared with extrapolations from lower-energy data based on dispersion relations, and with the UA4 value at √s =546 GeV.
Results of least square's fit to the distribution.
Total cross section from fit to data.
We have measured $\rho$ , the ratio of the real to the imaginary part of the $p \bar{p}$ forward elastic scattering amplitude, at $\sqrt{s}$ = 1.8 TeV. Our result is $\rho$ = 0.132 $\pm$ 0.056; this can be combined with a previous measurement at the same energy to give $\rho$ = 0.135 $\pm$ 0.044.
Measured value of the total cross section.
The measured value of the ratio of real to imaginary part of the forward scattering amplitude.
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.
Parity nonconservation in proton-proton scattering has been studied by measuring the angle-integrated longitudinal analyzing power A z . We found A z (13.6 MeV)=(−1.5±0.5)×10 −7 . The error includes uncertainties due to statistics and corrections, as well as upper limits on systematic effects. The experimental result is discussed with respect to recent theoretical calculations.
No description provided.
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.
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.
A precise measurement of p̄p elastic scattering in the Coulomb-strong interaction interference region was performed at the CERN Sp̄pS Collider at a centre-of-mass energy of 541 GeV. The ratio of the real to the imaginary part of the forward elastic scattering amplitude was found to be ρ = 0.135 ± 0.015. The slope of the exponential fall off of the strong interaction part was also measured to be b = 15.5 ± 0.1 GeV −2 .
No description provided.
Real part of amplitude extracted using a more precise UA4 measurement. (1 +RE(AMP)/IM(AMP)**2)SIG(TOT) = 63.5 +- 1.5 MB (Bozzo et al. PL 147B(1984)392).
We present preliminary results on the measurement of a variety of exclusive hadron interactions at center of mass scattering angles of 90°. Data are also presented which show the relative transparency of nuclei to πp and pp elastic scattering in this kinematic range.
No description provided.
No description provided.
No description provided.
The angular distributions of the analyzing power A y and of the differential cross section d σ/ d Ω in p p elastic scattering have been measured at 439 and 544 MeV/c. The results of A y are compared with various theoretical models.
Data requested from authors.
Legendre fit polynomials.
Normalized Legendre fit polynomials.
The differential cross section for elastic antiproton—proton scattering at s =1.8 TeV has been measured over the t range 0.034⩽| t |⩽0.65 (GeV/ c ) 2 . A logarithmic slope parameter, B , of 16.3±0.3 (GeV/ c ) −2 is obtained. In contrast to lower energy experiments, no change in slope is observed over this t range.
Numerical values from FERMILAB-FN-562 suppliedto us by R. Rubinstein. Statistical errors only. t values at centre of each bin.
Nuclear slope parameter. Error contains 0.3 GeV**-2 systematic uncertainty folded.
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.
Full angular distributions of the differential cross-section dσ/dμ and of the analysing power A y in p p elastic scattering have been measured at 697 MeV/ c . The results of A y are compared with the predictions of various theoretical models.
No description provided.
No description provided.
Legendre Polynomials from fit to angular distribution (LEG(L=0)=3.59 +- 0.02).
The high antiproton-proton luminosity obtained by using a target system consisting of a hydrogen gas-jet crossing a coasting beam of cooled antiproton circulating in one of the rings of CERN's ISR provides the possibility to measure low cross section reactions with very high precision. We present measurements of the antiproton-proton elastic cross section at 90° CM at incident momenta between 3.5 GeV/ c and 5.7 GeV/ c . The precision of these measurements is much higher than previously reported results. The data show that the cross section of this reaction decreases faster than s −12 over this momentum range.
No description provided.
No description provided.
We have studied proton-antiproton elastic scattering at s=1800 GeV at the Fermilab Collider, in the range 0.02<|t|<0.13 (GeV/c)2. Fitting the distribution by exp(−B|t|), we obtain a value of B of 17.2±1.3 (GeV/c)−2.
No description provided.
Error contains estimate of systematic effects.
Proton-antiproton elastic scattering was measured at the CERN SPS Collider at the centr-of-mass energy s =546 GeV in the Coulomb interference region. The data provide information on the phase of the hadronic amplitude in the forward direction. The conventional analysis gives for the ratio ϱ of the real to the imaginary part of the hadronic amplitude the result ϱ =0.24±0.04.
Axis error includes +- 0.025/0.025 contribution (Normalisation was fixed using a previous UA4 measurement of the total cross section: sig(name=tot)*(1 + alpha**2)).
Best estimate of alpha(rho).