Proton-Proton Elastic Scattering Research Articles

Transverse Spin Asymmetries in the CNI Region of Elastic Proton-Proton Scattering at s=200 GeV

Precise measurements of transverse spin asymmetries in proton-proton elastic scattering at very small values of four-momentum transfer squared, [Formula: see text], have been performed using the Relativistic Heavy Ion Collider (RHIC) polarized proton beams. The measurements of both single and double spin asymmetries were made at the center-of-mass energy [Formula: see text] GeV and in the region [Formula: see text] [Formula: see text], which was accessed using Roman Pot devices incorporated into the STAR experimental setup. The obtained set of asymmetries is sensitive to the poorly known hadronic contribution to the spin-flip amplitudes and provide significant constraints for the theoretical descriptions of the reaction mechanism of proton-proton elastic scattering at high energies.

Quark, Gluon, Odderon Contributions to Total Cross Section of Proton-Proton Elastic Scattering at High Energies

Based on the quark-gluon structure of nucleon and the existence of Odderon in nucleon via gluon self-interaction, the elastic scattering of pp at high energies is studied. Our theoretical predictions reproduce experimental data perfectly. The contributions from individual terms of quark-quark, gluon-gluon interactions, quark-gluon interference and the Odderon terms to total cross section are analyzed. In addition to the leading quark-quark contribution, the Odderon contribution is quite important. In particular, the Odderon plays an essential role in fitting to data. Therefore, We may claim that the high energy pp and p̄p elastic scattering may be good processes to search for the Odderon, the three Reggeized gluon bound states.

High Energy Proton-Proton Elastic Scattering in the Pomeron Exchange Model**The project supported in part by National Natural Science Foundation of China under contract numbers 19975053, 19835010, and 10075081.

We study high energy proton-proton elastic scattering in the framework of Pomeron exchange model. The cross section of the process are calculated without any free parameters. Our finding is that Pomeron exchange theory gives perfect fits to total cross section at the energy of higher than 10 GeV and to differential cross section at the momentum transfer |t| less than 1.5 GeV2. For total cross section at lower energy and differential cross section at larger momentum transfer region of , the Pomeron exchange theory needs to be improved.

Proton-Proton Elastic Scattering Excitation Functions at Intermediate Energies

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.Received 8 November 1996DOI:https://doi.org/10.1103/PhysRevLett.78.1652©1997 American Physical Society

Proton-Proton Elastic Scattering in the Several GeV Region

Proton-Proton Elastic Scattering in the Several GeV Region

Dipole Pomeron and Proton-Proton Elastic Scattering at High Energies

The differential and total cross sections for high energy pp elastic scattering in the energy range 30�8:;;; st :;;; 62 GeV, with -t extending up to 8 (GeV/c)2, have been fitted with a dipole pomeron model.

Phenomenological Analysis on Proton-Proton Elastic Scattering in the Forward Region

Phenomenological Analysis on Proton-Proton Elastic Scattering in the Forward Region

Proton-Proton Elastic Scattering at High Energy and Multiple Scattering. III

The angular distribution of proton-proton elastic scattering in ISR energy region, 23 ≲√s ≲62 GeV, is analyzed on the basis of composite model of hadrons. The inward moving of the position of dip and the growth of second bump with energy are explained in terms of the multiple scattering process between constituents (urbaryons), by using the diffractive amplitude of urbaryons which is phenomenologically determined so as to be dependent on energy. The characteristic radius √≪r2 >, root mean square distance between centers of a proton and its constituent urbaryons, is well fixed to be 0.6 fermi in the whole ISR energy range, which results in the growth of second bump when combined with the shrinking forward peak of urbaryon scattering. The behavior of dip and bump is predicted at much higher energies. The inelastic overlap function is also discussed both in momentum and in impact parameter space.

Measurement of Elastic Proton-Proton Scattering in Pure Initial-Spin States

Measurement of Elastic Proton-Proton Scattering in Pure Initial-Spin States

Measurements of the Polarization in Proton-Proton Elastic Scattering from 2.50 to 5.15GeVc

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 $\frac{\mathrm{GeV}}{c}$, and for values of the momentum transfer variable $\ensuremath{-}t$ from 0.2 to 2.0 ${(\frac{\mathrm{GeV}}{c})}^{2}$. The final results from $p\ensuremath{-}p$ elastic scattering presented here extend our knowledge of the polarization to much larger values of $\ensuremath{-}t$ than the results of previous measurements. Outstanding features revealed by these polarization data include (1) the development of a dip at about $\ensuremath{-}t=0.7 {(\frac{\mathrm{GeV}}{c})}^{2}$, with (2) a substantial secondary peak at larger values of $\ensuremath{-}t$ 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.

Proton-Proton Elastic Scattering Including Spin

A model for the description of proton-proton scattering at infinite energies is presented which includes the spin of the interacting particles in a natural way, by an appropriate generalization of the eikonal. Results which agree with current experimental data on several points are presented. In the limit that spin is neglected, previous results given by Chou and Yang are reproduced. An application to $p\overline{p}$ scattering is also discussed.

Unified Picture of Proton-Proton Elastic Scattering at All Angles from 3 to 24 GeV/c

We have investigated $\mathrm{pp}$ elastic scattering on the basis of smooth distributions for the helicity-nonflip and -flip amplitudes in the impact parameter $b$. We show how these distributions change with energy. We give interpretations for the shrinkage of the forward diffraction peak, the break in $\frac{d\ensuremath{\sigma}}{\mathrm{dt}}$ at $|t|\ensuremath{\approx}1$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{2}$, and the observed pronounced structure in the $\mathrm{pp}$ polarization.

On the Shrinkage of Forward Peaks of Elastic Proton-Proton Scattering

On the Shrinkage of Forward Peaks of Elastic Proton-Proton Scattering

Proton-Proton Elastic Scattering from 9.6 to 13.6 MeV

Accurate differential-cross-section data for proton-proton elastic scattering are presented at 9.690, 9.918, and 13.600 MeV. These data agree with current energy-dependent phase-shift analyses and resolve discrepancies between previous sets of data and between those data and the phenomenological analysis.

Energy Dependence of the Slope of the Forward Peak in Elastic Proton-Proton Scattering

The recent Serpukhov data show that the forward slope of the elastic p-p differential cross sections increases with energy above 20 Ge V / c.1> The purpose of this note is to discuss a simple diffraction model which is capable of explaining such a shrinkage of the forward peaks. Let us assume that the aggregate of inelastic processes has, as far as their effects on the elastic process are concerned, some simple representation and can be effectively expressed by a two-body channel p + p where p is a hypothetical isobar. In the following discussion we treat p and p as spinless particles. Assuming the dominance of the diffraction scattering for small momentum transfer elastic scattering, the partial wave S-matrix for elastic protonproton scattering may be written as2>

Proton-Proton Elastic Scattering at 15, 20 AND 30 BeV/c

Proton-proton elastic scattering has been measured at 15.2, 20.0, and 29.7 BeV/c. The data at 20.0 BeV/c confirm the presence of a break at $\ensuremath{-}t\ensuremath{\cong}1.2$ ${(\mathrm{B}\mathrm{e}\mathrm{V}/\mathit{c})}^{2}$. The data at 29.7 BeV/c show essentially the same behavior. The cross section is still falling with increasing energy in this $\ensuremath{-}t$ range.

Does the Slope of the High-Energy Elastic Proton-Proton Scattering Cross Section Increase at Small Momentum Transfer?

Experimental information relating to the slope of the elastic proton-proton scattering cross section in the region of $\ensuremath{-}t=0.15$ ${(\mathrm{B}\mathrm{e}\mathrm{V}/\mathit{c})}^{2}$ is reviewed. For proton energies greater than 18 BeV, most of the available data indicate that the slope changes from less than 9.0 ${(\mathrm{B}\mathrm{e}\mathrm{V}/\mathit{c})}^{\ensuremath{-}2}$ for $\ensuremath{-}tg0.2$ ${(\mathrm{B}\mathrm{e}\mathrm{V}/\mathit{c})}^{2}$ to a value greater than 10.0 ${(\mathrm{B}\mathrm{e}\mathrm{V}/\mathit{c})}^{\ensuremath{-}2}$ for $\ensuremath{-}tl0.15$ ${(\mathrm{B}\mathrm{e}\mathrm{V}/\mathit{c})}^{2}$.

Polarization Effects in High-Energy Elastic Proton-Proton Scattering

Polarization Effects in High-Energy Elastic Proton-Proton Scattering

Proton-Proton Elastic Scattering at High Energies and Large Angles, and the Incoherent Droplet Model

A study has been made of the elastic proton-proton scattering at high energies and large angles, using a model first proposed by K. Huang. This model decomposes a proton during collision into $N$ subunits and recombines them after collision in an incoherent combinatorial manner. The technique used is more general than the asymptotic methods used by Huang in obtaining the probabilities for the final states. The new procedure allows us to extend the range of validity for the model, since asymptotic expansions are no longer used. The analysis is limited to spinless protons, and to regions of high energy where there exists no discontinuity in the shape of the angular distribution such as was found by Allaby et al. around ${P}_{L}=8 \mathrm{to} 11$ BeV/c. The theoretical curves are in good agreement with the experimental results from ${\ensuremath{\theta}}_{\mathrm{c}.\mathrm{m}.}=65\ifmmode^\circ\else\textdegree\fi{} \mathrm{to} 90\ifmmode^\circ\else\textdegree\fi{}$ and ${P}_{L}=14 \mathrm{to} 27$ BeV/c, while the asymptotic expressions are in good agreement only from around 76\ifmmode^\circ\else\textdegree\fi{} to 90\ifmmode^\circ\else\textdegree\fi{}. The experimentally observed quenching of large-momentum-transfer states as the energy increases is reproduced.

Regge Behavior at Large Angles, and the Dolen-Horn-Schmid Duality in Elastic Proton-Proton Scattering

Elastic proton-proton scattering is studied at high energies. It is shown that at large angles the data is fitted by $\frac{d\ensuremath{\nu}}{d\ensuremath{\Omega}}={s}^{\ensuremath{-}1}K(t){(\frac{\ensuremath{\nu}}{{s}_{0}})}^{2\ensuremath{\alpha}(t)}$, where $\ensuremath{\nu}=\frac{1}{2}(s\ensuremath{-}u)$, which indicates that Regge theory is good at all angles at high energy. We also show how to avoid double counting parallelling Dolen, Horn, and Schmid.