Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userMultiple Hard Partonic Collisions with Correlations in Proton-Proton Scattering
127
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
We propose a simple method for incorporating correlations into the impact parameter space description of multiple (semi-)hard partonic collisions in high energy hadron-hadron scattering. The perturbative QCD input is the standard factorization theorem for inclusive dijet production with a lower cutoff on transverse momentum. The width of the transverse distribution of hard partons is fixed by parameterizations of the two-gluon form factor. We then reconstruct the hard contribution to the total inelastic profile function and obtain corrections due to correlations to the more commonly used eikonal description. Estimates of the size of double correlation corrections are based on the rate of double collisions measured at the Tevatron. We find that, if typical values for the lower transverse momentum cutoff are used in the calculation of the inclusive hard dijet cross section, then the correlation corrections are necessary for maintaining consistency with expectations for the total inelastic proton-proton cross section at LHC energies.
rate research
Read More
The CMS collaboration at the LHC has reported a remarkable and unexpected phenomenon in very high-multiplicity high energy proton-proton collisions: a positive correlation between two particles produced at similar azimuthal angles, spanning a large range in rapidity. We suggest that this ridge-like correlation may be a reflection of the rare events generated by the collision of aligned flux tubes connecting the valence quarks in the wave functions of the colliding protons. The spray of particles resulting from the approximate line source produced in such inelastic collisions then gives rise to events with a strong correlation between particles produced over a large range of both positive and negative rapidity. We suggest an additional variable that is sensitive to such a line source which is related to a commonly used measure, ellipticity.
This report summarizes some of the recent HERA results obtained by studying hard processes in ep-scattering. By resolving the structure of the proton, hard ep-reactions provide information on the parton content of the proton and may give insight into the dynamics of the exchanged parton cascade. In addition, their study offers the possibility to test the Standard Model, in particular perturbative Quantum Chromodynamics, on which the theoretical predictions on ep-scattering cross sections are generally based. Any observed deviation between the data and existing theoretical models would either indicate the need to calculate higher order contributions or hint at signs of new physics.
We consider the charge-odd correlations (COC) in cross sections of processes of production of charged particles. The cases of a muonic pair and pion systems $pi^{+}pi^{-},pi^{+}pi^{-}pi^{0}$ are considered in detail for electron-proton or photon-proton collisions in the proton fragmentation region kinematics. COC arise from interference of amplitudes which describe the different mechanisms of charged leptons (pions) creation. One of them corresponds to production of particles in the charge-odd state (one virtual photon or vector meson annihilation to this system of particles) and the other corresponds to the charge-even state of produced particles (creation by two photons). COC for muon-antimuon pair creation have a pure QED nature and can be considered as a normalization process. The processes with pion production are sensitive to some characteristics of proton wave functions and, besides, can be used for checking the anomalous and normal parts of the effective pionic lagrangian. Three electromagnetic currents operator matrix element can be measured in photon-proton interactions with lepton pair production. For this aim a charge-odd combination of cross sections can be constructed as a conversion of leptonic 3-rank tensor with hadronic ones. These experiments can be considered as an alternative to deep virtual Compton scattering.
Kinematic correlations for pairs of beauty hadrons, produced in high energy proton-proton collisions, are studied. The data sample used was collected with the LHCb experiment at centre-of-mass energies of 7 and 8 TeV and corresponds to an integrated luminosity of 3 fb$^{-1}$. The measurement is performed using inclusive $brightarrow J/psi X$ decays in the rapidity range $2<y^{J/psi}<4.5$. The observed correlations are in good agreement with theoretical predictions.
We analyze the inclusive spectra of hadrons produced in $pp$ collisions at high energies in the mid-rapidity region within the soft QCD and perturbative QCD assuming the possible creation of the soft gluons at low intrinsic transverse momenta $k_t$. From the best description of the LHC data we found the parametrization of the unintegrated gluon distribution which at low $k_t$ is different from the one obtained within the perturbative QCD.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
