No Arabic abstract
The data on p$mathrm{bar p}$ elastic scattering at 1.8 and 1.96 TeV are analysed in terms of real and imaginary amplitudes, in a treatment with high accuracy, covering the whole t-range and satisfying the expectation of dispersion relation for amplitudes and for slopes. A method is introduced for determination of the total cross section and the other forward scattering parameters and to check compatibility of E-710, CDF and the recent D0 data. Slopes $B_R$ and $ B_I$ of the real and imaginary amplitudes, treated as independent quantities, influence the amplitudes in the whole t-range and are important for the determination of the total cross section. The amplitudes are fully constructed, and a prediction is made of a marked dip in $ dsigma/dt$ in the $|t|$ range 3 - 5 GeV$^2$ due to the universal contribution of the process of three gluon exchange.
We present a measurement of the elastic differential cross section $dsigma(pbar{p}rightarrow pbar{p})/dt$ 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 $pbar{p} $ Collider operating conditions at sqrt(s) = 1.96 TeV and covers the range $0.26 <|t|< 1.2 GeV^2$. For $|t|<0.6 GeV^2$, dsigma/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|.
Proton-proton elastic scattering has been measured by the TOTEM experiment at the CERN Large Hadron Collider at $sqrt{s} = 7 $ TeV in special runs with the Roman Pot detectors placed as close to the outgoing beam as seven times the transverse beam size. The differential cross-section measurements are reported in the |t|-range of 0.36 to 2.5 GeV^2. Extending the range of data to low t values from 0.02 to 0.33 GeV^2,and utilizing the luminosity measurements of CMS, the total proton-proton cross section at sqrt(s) = 7 TeV is measured to be (98.3 +- 0.2(stat) +- 2.8(syst)) mb.
The observed enhancement of $pbar p$-production near the threshold in radiative decays of $J/psi$ and $e^+e^-$-annihilations can be explained with final state interactions among the produced $Nbar N$ system, where the enhancement is essentially determined by $Nbar N$ elastic scattering amplitudes. We propose to use an effective theory for interactions in a $Nbar N$ system near its threshold. The effective theory is similar to the well-known one for interactions in a $NN$ system but with distinctions. It is interesting to note that in the effective theory some corrections to scattering amplitudes at tree-level can systematically be summed into a simple form. These corrections are from rescattering processes. With these corrected amplitudes we are able to describe the enhancement near the threshold in radiative decays of $J/psi$ and $e^+e^-$-annihilations, and the $pbar p$ elastic scattering near the threshold.
With analytical representation for the pp scattering amplitudes introduced and tested at lower energies, a description of high precision is given of the $dsigma/dt$ data at $sqrt{s}$= 13 TeV for all values of the momentum transfer, with explicit identification of the real and imaginary parts. In both $t$ and $b$ coordinates the amplitudes have terms identified as of non-perturbative and perturbative nature, with distinction of their influences in forward and large $|t|$ ranges and in central and peripheral regions respectively. In the forward range, the role of the Coulomb-nuclear interference phase is investigated. The energy dependence of the parameters of the amplitudes are reviewed and updated, revealing a possible emergence of a peculiar behavior of elastic and inelastic profiles in b-space for central collisions, which seems to be enhanced quickly at higher energies. Some other models are also briefly discussed in comparison, including the above mentioned behavior in b-space.
We present a measurement of the inclusive jet cross section using the Run II cone algorithm and data collected by the D0 experiment in p pbar collisions at a center-of-mass energy sqrt(s)=1.96 TeV, corresponding to an integrated luminosity of 0.70 fb^(-1). The jet energy calibration and the method used to extract the inclusive jet cross section are described. We discuss the main uncertainties, which are dominated by the jet energy scale uncertainty. The results cover jet transverse momenta from 50 GeV to 600 GeV with jet rapidities in the range -2.4 to 2.4 and are compared to predictions using recent proton parton distribution functions. Studies of correlations between systematic uncertainties in transverse momentum and rapidity are presented.