Measurements of the differential cross sections for π−d elastic scattering in the backward angular region are presented. These measurements were made at thirteen incident-pion momenta ranging from 496 to 1050 MeV/c, over the center-of-mass angular range 148° to 177°. The experiment was performed at the LBL Bevatron. Experimental apparatus consisted of a liquid deuterium target and a double-arm spectrometer which included scintillation-counter hodoscopes. Center-of-mass differential cross sections were found to be generally smooth over the angular range covered and can be fitted with low-order polynomials. The extrapolated differential cross sections at 180° scattering angle were found to decrease rapidly with increasing momentum, with a prominent peak near 700 MeV/c and a shoulder near 900 MeV/c. These data are discussed in terms of existing models employing "d*" structures, and are compared with other similar measurements.
Compton scattering from protons has been measured between 650 MeV and 1350 MeV for angles between 60° and 140° CM.
No description provided.
Differential cross sections for π−p elastic scattering over the angular range 155° to 177° in the center-of-mass system have been measured at 33 incident pion momenta in the range 600 to 1280 MeV/c. The experiment, which was performed at the Bevatron at the Lawrence Berkeley Laboratory, employed a liquid hydrogen target, a double-arm spectrometer, and standard counter techniques to detect the elastic events. The data from this experiment are compared to all other published data in this momentum region. The over-all agreement is good. The data of this experiment are also compared with the results of the recent phase-shift analysis by Almehed and Lovelace. In the momentum region between 700 and 900 MeV/c, the slope of the backward angular distribution goes rapidly through zero from negative to positive, and the magnitude of the differential cross section falls by more than a factor of 10. Momentum-dependent structure is seen in the extrapolated differential cross sections at 180°. Two prominent dips in the 180° differential cross sections appear at 880 and 1150 MeV/c. This structure is discussed in terms of a direct-channel resonance model that assumes only resonant partial waves are contributing to the cross sections for large scattering angles.
No description provided.
No description provided.
No description provided.
The differential cross sections for π−p elastic scattering over the angular range 155° to 177° in the center of mass have been measured at 33 incident-pion momenta in the range 600 to 1280 MeV/c. Angular distributions are presented. The extrapolated differential cross sections at 180° show considerable structure, in particular a dip near 1150 MeV/c. In general the near-180° cross sections do not agree with existing phase shift solutions above 1000 MeV/c
INTERPOLATED DATA.
INTERPOLATED DATA.
INTERPOLATED DATA.
A measurement of the total $pp$ cross section at the LHC at $\sqrt{s}=7$ TeV is presented. In a special run with high-$\beta^{\star}$ beam optics, an integrated luminosity of 80 $\mu$b$^{-1}$ was accumulated in order to measure the differential elastic cross section as a function of the Mandelstam momentum transfer variable $t$. The measurement is performed with the ALFA sub-detector of ATLAS. Using a fit to the differential elastic cross section in the $|t|$ range from 0.01 GeV$^2$ to 0.1 GeV$^2$ to extrapolate to $|t|\rightarrow 0$, the total cross section, $\sigma_{\mathrm{tot}}(pp\rightarrow X)$, is measured via the optical theorem to be: $$\sigma_{\mathrm{tot}}(pp\rightarrow X) = 95.35 \; \pm 0.38 \; ({\mbox{stat.}}) \pm 1.25 \; ({\mbox{exp.}}) \pm 0.37 \; (\mbox{extr.}) \; \mbox{mb},$$ where the first error is statistical, the second accounts for all experimental systematic uncertainties and the last is related to uncertainties in the extrapolation to $|t|\rightarrow 0$. In addition, the slope of the elastic cross section at small $|t|$ is determined to be $B = 19.73 \pm 0.14 \; ({\mbox{stat.}}) \pm 0.26 \; ({\mbox{syst.}}) \; \mbox{GeV}^{-2}$.
The measured total cross section, the first systematic error accounts for all experimental uncertainties and the second error for the extrapolation t-->0.
The nuclear slope of the differential eslastic cross section at small |t|, the first systematic error accounts for all experimental uncertainties and the second error for the extrapolation t-->0.
The Optical Point dsigma/(elastic)/dt(t-->0), the total elastic cross section and the observed elastic cross section within the fiducial volume. The first systematic error accounts for all experimental uncertainties and the second error for the extrapolation t-->0.
The differential cross-section for π - -p elastic scattering over the angular range 125° to 178° center of mass has been measured between 1.28 and 3.0 GeV/ c . Considerable structure is found and is discussed in terms of direct channel resonances.
No description provided.
No description provided.
No description provided.
As part of a program of measurements of the πp system we have measured the backward differential cross section for π+p elastic scattering at 16 momenta from 1.25 to 2.0 GeV/c inclusive. The angular region covered is -0.46 to -0.97 in cosθc.m.. The high resolution in u of 0.03 to 0.04 (GeV/c)2, together with good statistics, enables a detailed examination of the momentum and angular dependence of structure in this channel. The data are compared with distributions from other experiments and with the most recent phaseshift fit.
No description provided.
No description provided.
No description provided.
We have measured the backward differential cross section in π−p elastic scattering at 31 momenta from 1.28 to 3.0 GeV/c. These measurements covered the center-of-mass angular range of 125°-178° corresponding to −0.570≲cosθc.m.≲−0.999. Considerable structure in the angular distribution is found. We compare these data with data from other experimets and to predictions made by the latest phase-shift solution. We find, in general, good agreement with other data in the few regions of overlap. The fits from the phase-shift solution do not accurately reproduce these data at low momenta below 1.9 GeV/c but give excellent agreement above this momentum.
No description provided.
No description provided.
No description provided.
We report measurements of the polarization parameters in π+p and π−p elastic scattering at an incident momentum of 100 GeV/c. The results cover the range 0.18<~−t<~1.4 GeV2 and are in agreement with current Regge-model predictions.
No description provided.
No description provided.
No description provided.
The differential cross sections of the elastic p p reaction have been measured at 1.2, 1.4, 1.8 and 2.6 GeV/ c incident p momentum. The measurements have been performed at the CERN PS using a system of multiwire proportional chambers. The angular region covers scattering angles from 0 to ∼200 mrad. Interference effects between the Coulomb and the nuclear amplitudes are used to derive the ratio of the real to imaginary part of the forward nuclear amplitude. These ratios are compared with theoretical predictions.
'MS'. 'TBIN'.
'MS'. 'TBIN'.
'MS'. 'TBIN'.
Excitation functions of proton-proton elastic scattering cross sections have been measured in narrow steps for projectile momenta pp (energies Tp) from 1100 to 3300MeV/c (500 to 2500 MeV) in the angular range 35°≤Θc.m.≤90° with a detector providing ΔΘc.m.≈1.4° resolution. Measurements have been performed continuously during projectile acceleration in the cooler synchrotron COSY with an internal CH2 fiber target, taking particular care to monitor luminosity as a function of Tp. The advantages of this experimental technique are demonstrated, and the excitation functions obtained are compared to existing cross section data. No evidence for narrow structures was found.
No description provided.
No description provided.
No description provided.
Antiproton-proton elastic scattering has been measured at 100 GeV/c for 0.5<−t<2.5 (GeV/c)2 and at 200 GeV/c for 0.9<−t<4 (GeV/c)2. The data show that the −t≃1.4 (GeV/c)2 dip recently observed at 50 GeV/c persists to higher incident momenta. Proton-proton measurements made at the same beam momenta show similar structure.
CLEAR DIP OBSERVED AT -T=1.4 (GEV/C)**2.
Proton-proton elastic scattering using 201- and 400-GeV/c extracted beams at Fermilab has been measured in the region 4.9<−t<14.4 GeV2. Contrary to predictions of diffraction models, there is no sign of a second dip or "break," and the slope A in the fit exp(At) is smaller than predicted. It drops from 1.5 to 0.8 GeV−2 over our t range. The shape of the t distribution can be fitted by the power law dσdt∝t−8.4 which is close to a quantum-chromodynamics (QCD) prediction of t−8. At fixed t the 201-GeV/c cross sections are about 2.3 times those at 400 GeV/c which is compatible with the QCD and constituent-interchange-model prediction that dσdt∝s−10 at fixed ts.
LOW T.
HIGH T.
LOW T.
Proton-proton elastic scattering has been measured in the region 4.9<|t|<12.1 GeV2 at a beam momentum of 201 GeV/c. If the form exp(At) is fitted to the data, the exponent A gradually changes from 1.5 to 0.9 GeV−2 over our t range. The data are consistent with the form exp(−6.6p⊥). A comparison with intersecting storage ring results shows that in this kinematical region the slopes are about the same, but dσdt at fixed t is still dropping with energy.
7904 ELASTIC EVENTS.
1030 ELASTIC EVENTS.
The differential cross sections of the combined elastic and break-up K − d reaction have been measured at 1.21, 1.42 and 2.61 GeV/ c incident K − momentum. The measurements have been performed at the CERN PS using multiwire proportional chambers. The values of the invariant momentum transfer t explored (0.0005<| t |<0.1 GeV 2 ) include the Coulomb-nuclear interference region. The differential cross sections have been analysed in the framework of the Glauber impact-parameter formalism. The observed interference effects have been used to derive the ratio of the real to imaginary part of the forward K − n nuclear amplitude.
USING OPTICAL THEOREM: IMAGAMP1 = 0.0403*P*SIG.
We present the results on total channel cross-sections obtained in the Saclay 180 l HBC exposed to a separated K− beam at Nimrod. The cross-sections for each channel are given at 13 incident K− momenta between 1.26 and 1.84 GeV/c.
No description provided.
Differential cross-sections for proton-proton elastic scattering have been measured covering the angular range from 50° to 90° c.m. at twelve incident momenta from 1.3 to 3.0 GeV/c. The angular distributions are quite smooth, but there is evidence of structure in the energy dependence of fixed-angle cross-sections at |t| ∼ 1 (GeV)2.
No description provided.
No description provided.
No description provided.
Proton-proton elastic scattering at 400 GeV/c has been measured in the region 5.4<−t<14.4 GeV2 with no sign of a second dip or "break." If the data are fitted by exp(At), the slope A decreases from 1.5±0.1 to 0.7±0.2 GeV−2 over the range. At fixed t the 400-GeV/c cross sections are about 0.6 times those at 200 GeV/c in this t range. At fixed θc.m.=15°, dσdt∝s−n where n=9.7±0.3.
No description provided.
No description provided.
K − p reactions have been studied at 13 different incident momenta between 1138 and 1434 MeV/ c . This interval corresponds to a mass of the K − p system varying from 1858 to 1993 MeV. About 300 000 photographs were taken in the 81 cm Saclay hydrogen bubble chamber exposed to a separated K − beam at the CERN proton-synchrotron. A total of about 44 000 events were analyzed, from which partial and differential cross sections were determined. Polarizations were obtained for the two-body reactions where the decay of the Λ or Σ hyperon allowed their measurement. Data for the two-body channels are presented here as well as for the main quasi-two-body reactions.
PARTIAL CROSS SECTIONS. DATA AT 1.305 TO 1.434 GEV/C FOR FINAL STATES K- P, K- P PI0 AND K- N PI+ COME FROM THE HAIFA GROUP, S. DADO ET AL.
No description provided.
No description provided.
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'.
We have measured the differential cross section of the reaction π − p→ π − p in the range 0.92 ⩽ cos θ c.m. ⩽ 0.99 at 15 momenta between 0.875 and 1.580 GeV/ c . The results we report complete the available data; previous measurements of this reaction do not extend beyond cos θ c.m. =0.90. We compare our experimental results with dispersion relation predictions. A comparison of our results for B , the slope of the differential cross section, with earlier results shows many discrepancies.
No description provided.
No description provided.
No description provided.
We have analyzed the two-prong final states in π+p interactions at 3.9 GeVc. Our result for elastic scattering is σ (elastic) = 6.50±0.1 mb (statistical error only). We find the elastic slope to be 6.61±0.14 (GeVc)−2. We find the elastic forward cross section to be 40.0±1.4 mb(GeVc)2. We have applied a longitudinal-momentum analysis to the one-pion-production channel. We find the cross section for the reaction π++p→π++π0+p to be 2.30±0.06 mb and that for π++p→π++π++n to be 1.45±0.05 mb. For resonance-production cross sections in these channels we find Δ(1236)=0.60±0.07 mb, ρ(760)=0.86±0.06 mb, and diffraction dissociation = 1.69±0.11 mb. We find that we can satisfactorily fit all distributions in the one-pion-production channel without assuming any phase-space production. In the missing-mass channel we observe dominant Δ++(1236) production plus evidence for A2+ production.
No description provided.
No description provided.
No description provided.
Final results of our measurements of elastic proton-proton scattering at the CERN Intersecting Storage Rings (ISR) for c.m. energies √ s from 23 to 63 GeV and momentum transfers | t | from 0.8 to 10 GeV 2 are presented. Absolute differential cross sections have been obtained using the split-field magnet detector facility (SFM) at the five standard energies for integrated luminosities ranging from 0.3 to 4.9 (pb) −1 . The rising total cross section is found to define a scale for diffractive phenomena near the forward peak, including the position of the diffraction minimum near t = −1.4 GeV 2 . The cross section at the minimum is strongly energy dependent, approximately as the ratio of the real to imaginary part of the scattering amplitude in the forward direction. The phase of the scattering amplitude is found to change sign near the minimum. The component of diffraction scattering beyond the second maximum has a much weaker t -dependence than expected in simple eikonal or constituent pictures connecting this region to the forward peak. A further break in slope is observed near t = −6 GeV 2 . There is no evidence for another minimum for t values up to 10 GeV 2 .
No description provided.
No description provided.
No description provided.
Elastic scattering of p¯ on p has been studied for cosθc.m. between -0.88 and -1.0 and Plab(p¯) between 0.70 and 2.16 GeV/c. The momentum dependence of the cross section shows a sharp dip at 0.9 GeV/c and a broad peaking around 1.4 GeV/c. The possibility of the peak resulting from direct formation of boson resonances has been studied. Alternatively, a diffraction model agrees qualitatively with our data and other elastic data at different angles.
'1'. '2'. '3'.
No description provided.
No description provided.
The differential cross sections of the reactions e + e − → e + e − and e + e − → λλ are measured at energies between 33.0 and 36.7 GeV. The results agree with the predictions of quantum electrodynamics. A comparison with the standard model of electroweak interaction yields sin 2 θ W = 0.25 ± 0.13.
No description provided.
The elastic and inelastic\(\bar p\)p cross sections at 70 GeV/c have been determined in an experiment performed at CERN using BEBC equipped with a TST. The topological cross sections were measured and the moments of the inelastic multiplicity distribution are 〈nc〉=6.16±0.09, 〈nc〉/D=2.04±0.05 andf2cc=2.97±0.03. The average number of Dalitz pairs per inelastic event is (3.12±0.09)×10−2. Assuming that these all arise from π0 decay the average π0 multiplicity is\(\langle n_{\pi ^0 } \rangle= 2.71 \pm 0.14\). The\(\bar p\)p−pp cross section differences lead to an annihilation cross section σA = 4.42±0.41 mb and the moments of the annihilation multiplicty distribution are 〈nA〉=8.0±0.3, 〈nA〉/D=2.5±0.2 andf2A−−=−1.4±0.3. An independent check of σA was made by investigating fast forward charged and neutral secondary interactions in the TST and in the surrounding neon-hydrogen mixture, and gives a value σA = 5.0±1.6 mb. The ratio of fast\(\bar n\) to\(\bar p\) production in non-annihilation interactions at 70 GeV/c is found to be 0.45±0.11.
No description provided.
INELASTIC TOPOLOGICAL CROSS SECTIONS. NORMALIZED TO TOTAL INELASTIC CROSS SECTION OF 35.7 +- 0.5 MB (AYRES ET AL., PR D15, 3105).
No description provided.
The couplings of the Z 0 to charged leptons are studied using measurements of the lepton pair cross sections and forward-backward asymmetries at centre of mass energies near to the mass of the Z 0 . The data are consistent with lepton universality. Using a parametrisation of the lepton pair differential cross section which assumes that the Z 0 has only vector and axial couplings to leptons, the charged leptonic partial decay width of the Z 0 is determined to be Г ol+ol− = 83.1±1.9 MeV and the square of the product of the effective axial vector and vector coupling constants of the Z 0 to charged leptons to be a ̌ 2 ol v ̌ 2 ol = 0.0039± 0.0083 , in agreement with the standard model. A parametrisation in the form of the improved Born approximation gives effective leptonic axial vector and vector coupling constants a ̌ 2 ol = 0.998±0.024 and v ̌ 2 ol = 0.0044±0.0083 . In the framework of the standard model, the values of the parameters ϱ z and sin 2 θ w are found to be 0.998±0.024 and 0.233 +0.045 −0.012 respectively. Using the relationship in the minimal standard model between ϱ z and sin 2 θ w , the results sin 2 θ SM w = 0.233 +0.007 −0.006 is obtained. Our previously published measurement of the ratio of the hadronic to the leptonic partial width of the Z 0 is update: R z = 21.72 +0.71 −0.65 .
Cross sections corrected for the effects of efficiency and kinematic cuts. Errors have systematic effects folded.
Acceptance corrected cross sections. Statistical errors only.
Acceptance corrected cross sections. Statistical errors only.
None
The differential cross section and polarization in p−d elastic scattering have been measured at an incident laboratory momentum of 0.99 GeVc (kinetic energy 425 MeV) over most of the angular range. Elastic p−d scattering events from a CD2 target were selected by angular correlation, coplanarity, and time of flight. A significant feature of the results is the large positive polarization at backward scattering angles.
We present an analysis of electroweak leptonic couplings from high statistics experiments on Bhabha scattering and μ pair production at an energy of 34.5 GeV. The forward-backward charge asymmetry of the μ pairs was measured to be −0.098±0.023±0.005. The data were found to agree well with the standard theory of electroweak interaction giving sin2θW=0.27±0.07. The leptonic weak couplings were determined to begv=0.000±0.170 andgA=−0.481±0.055. The data were also used to investigate a class of composite models for leptons.
No description provided.
No description provided.
The differential cross sections for π − p elastic scattering have been measured near 180°, in the momentum range 875–1580 MeV/c. The results are compared with recent phase shift analysis, showing some notable discrepancies.
No description provided.
No description provided.
No description provided.
The real part of the proton proton elastic scattering amplitude has been determined from its interference with the Coulomb amplitude at total centre-of-mass energies up to 62 GeV. The observed steady increase of ϱ with energy indicates that the total proton proton cross section continues to increase well beyond this energy.
No description provided.
USING SIG AND SLOPE OBTAINED FROM INTERPOLATIONS OF PREVIOUS MEASUREMENTS.
Cross sections for the reactionse+e−→e+e− (Bhabha scattering) ande+e−→γγ are measured for center-of-mass (c.m.) energies\(\sqrt s \) between 12.0 and 34.6 GeV. The results agree with the predictions of Quantum Electrodynamics (QED) and the cut-off parameters are determined. From Bhabha scattering at the highest energy,\(\left\langle {\sqrt s } \right\rangle= 34.6 GeV\), the 1 δ limits 0.12<sin2 ϑw<0.38 are obtained for the weak mixing angle. The higher order (α3) QED processese+e−→e+e−γ ande+e−→γγγ are also studied and are found to agree with the α3 QED predictions. A search for excited electrons is carried out by investigating the (e±γ) invariant mass distribution in the reactione+e−→e+e−γ.
Angular distribution.
Angular distribution.
Differential cross sections for the processes e + e − → e + e − (Bhabha scattering) and e + e − → γγ have been measured with the TOPAZ detector at s =52 GeV . The results agree with the predictions of quantum electrodynamics (QED). The lower limits for the QED cut-off parameters have been obtained to be Λ + ⩾115 GeV and Λ − ⩾236 GeV for Bhabha scattering, and Λ + ⩾94 GeV and Λ − ⩾59 GeV for the reaction e + e − → γγ .
Statistical errors only.
Statistical errors only.
Ratio of experimental data to prediction for lowest order QED. Statistical errors only.
The cross section for the K L 0 p elastic scattering has been measured for the first time. The incident momentum and momentum transfer ranges are 3 ⩽ p ⩽ 13 GeV/ c , 0.1 ⩽ | t | ⩽ 1.3 GeV 2 . The results are compared to those of other experiments related to ours by isotopic spin conservation, finding agreement with some and discrepancies with others. The differential cross sections have been parametrized in the form A e bt . The coefficients show little or no dependence on energy, with A ≅ 9.8 mb · GeV −2 and b ≅ 4.7 GeV −2 . The effective linear trajectory has been determined and gives α 0 = 0.95 ± 0.15, α ′ = −0.35 ± 0.48 GeV −2 , in good agreement with dominance by pomeron exchange.
CROSS SECTIONS DEDUCED FROM THE 46 PCT OF EVENTS WHICH YIELD UNIQUE SOLUTIONS.
<RAW> CROSS SECTIONS DEDUCED FROM A STATISTICAL TREATMENT OF ALL EVENTS.
<SMOOTHED> CROSS SECTIONS DEDUCED FROM A STATISTICAL TREATMENT OF ALL EVENTS.
The neutron-proton elastic differential cross section has been measured with high statistics for incident momenta between 10 and 24 GeV/ c using wire spark chambers for the neutron detection. The t -range covered by previous experiments could thus be extended to 0.06–3 (GeV/ c ) 2 . In this t -interval the np cross section is found to be very similar to the corresponding pp cross section.
No description provided.
No description provided.
No description provided.
The parameters D, R, R' and P for pp elastic scattering have been measured in the centre-of-mass angular range 13 degrees to 58 degrees with an accuracy of about +or-0.02 at 209, 324, 379, 425 and 515 MeV. These results are incorporated with earlier data into a phase-shift analysis. Phase-shifts are generally in agreement with the theoretical predictions of the Paris group, although the F-wave spin-orbit combination is rather stronger than predicted. The fitted value for the pi 0pp coupling constant in g02=14.06+or-0.65.
No description provided.
No description provided.
No description provided.
A measurement of the total $pp$ cross section at the LHC at $\sqrt{s}=8$ TeV is presented. An integrated luminosity of $500$ $\mu$b$^{-1}$ was accumulated in a special run with high-$\beta^{\star}$ beam optics to measure the differential elastic cross section as a function of the Mandelstam momentum transfer variable $t$. The measurement is performed with the ALFA sub-detector of ATLAS. Using a fit to the differential elastic cross section in the $-t$ range from $0.014$ GeV$^2$ to $0.1$ GeV$^2$ to extrapolate $t\rightarrow 0$, the total cross section, $\sigma_{\mathrm{tot}}(pp\rightarrow X)$, is measured via the optical theorem to be: $\sigma_{\mathrm{tot}}(pp\rightarrow X) = {96.07} \; \pm 0.18 \; ({{stat.}}) \pm 0.85 \; ({{exp.}}) \pm 0.31 \; ({extr.}) \; {mb} \;,$ where the first error is statistical, the second accounts for all experimental systematic uncertainties and the last is related to uncertainties in the extrapolation $t\rightarrow 0$. In addition, the slope of the exponential function describing the elastic cross section at small $t$ is determined to be $B = 19.74 \pm 0.05 \; ({{stat.}}) \pm 0.23 \; ({{syst.}}) \; {GeV}^{-2}$.
The measured total cross section, the first systematic error accounts for all experimental uncertainties and the second error for the extrapolation t-->0.
The nuclear slope of the differential eslastic cross section at small |t|, the first systematic error accounts for all experimental uncertainties and the second error for the extrapolation t-->0.
The total elastic cross section and the observed elastic cross section within the fiducial volume.
The polarization parameter in proton-proton scattering has been measured at incident proton kinetic energies of 1.7, 2.85, 3.5, 4.0, 5.05, and 6.15 BeV and for four-momentum transfer squared between 0.1 and 1.0 (BeV/c)2. The experiment was done with an unpolarized proton beam from the Bevatron striking a polarized proton target. Both final-state protons were detected in coincidence and the asymmetry in counting rate for target protons polarized parallel and antiparallel to the scattering normal was measured. The maximum polarization was observed to decrease from 0.4 at 1.7 BeV to 0.2 at 6.1 BeV. The maximum of the polarization at all energies studied occurs at a four-momentum transfer squared of 0.3 to 0.4 (BeV/c)2.
'1'.
'2'.
'3'.
The Λ-proton elastic scattering cross section has been measured between 1 and 17 GeV/c in a bubble chamber experiment. These are the first measurements of the elastic cross section for pΛ>5 GeV/c. The Λ's were produced by 25-GeV/c proton interactions in a platinum target. The cross section falls from 22 to 4 mb over the region. No significant polarization is observed.
CORRECTION MADE FOR KL P --> KS P.
The neutron-proton elastic differential cross section has been measured for incident momenta between 10 and 70 GeV/c and for values of the momentum transfer squared between 0.1 and 2.8 (GeV/c) 2 . The forward peak and the break at about ∣ t ∣ = 1 (GeV/ c ) 2 are very similar to corresponding pp data.
No description provided.
No description provided.
A high-precision measurement of the differential cross section for Bhabha scattering (e+e−→e+e−) is presented. The measurement was performed with the MAC detector at the PEP storage ring of the Stanford Linear Accelerator Center, at a center-of-mass energy of 29 GeV. Effects due to electroweak interference are observed and agree well with the predictions of the Glashow-Salam-Weinberg model. The agreement between the data and the electroweak prediction rules out substructure of the electron up to mass scales of 1 TeV.
Error contains both statistics and systematics.
No description provided.
No description provided.
We present differential cross-section data for the reaction π+p→π+p near 180° in the center-of-mass system at beam momenta between 3.25 GeVc and 10 GeVc.
No description provided.
No description provided.
None
Incident alphas on protons were used to measure the elastic cross section in the backward hemisphere at 3.20, 4.00, 5.08 and 6.00 GeV/ c . The level and shape of the angular distributions are strongly dependent on energy. A backward peak shows up at 4.00 GeV/ c and become much steeper when the energy increases.
None
'1'. '2'. '3'.
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.
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).
We have measured the antiproton-proton elastic differential cross section in the center-of-mass angular range cosθ=−0.985 to +0.40 at six momenta between 1.6 and 2.2 GeV/c in a bubble-chamber experiment. We use the data to look for evidence of direct-channel boson resonances.
No description provided.
In an experiment at the Argonne Zero-Gradient Synchrotron we have measured values of the polarization parameter P(t) in the elastic scattering of negative pions, positive pions, positive kaons, and protons on protons at several incident laboratory momenta from 2.50 to 5.15 GeVc, and for values of the momentum transfer variable −t from 0.2 to 2.0 (GeVc)2. The final results from p−p elastic scattering presented here extend our knowledge of the polarization to much larger values of −t than the results of previous measurements. Outstanding features revealed by these polarization data include (1) the development of a dip at about −t=0.7 (GeVc)2, with (2) a substantial secondary peak at larger values of −t and (3) the gradual diminution of the maximum polarization with increasing energy. It is possible to fit the t dependence of the experimental results with a simple model. The energy dependence of the polarized cross sections is also discussed.
No description provided.
No description provided.
No description provided.
Measurements of π±p elastic differential cross-sections have been performed in the forward direction, using a missing-mass spark chamber spectrometer. The films have been seanned by an automatic apparatus. A phase-shift analysis of the experimental data has been done, leading to three solutions. Various experiments are proposed in order to resolve the ambiguities.
No description provided.
No description provided.
No description provided.
Forum