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H. Hosseinkhani

Publications and source records attributed to H. Hosseinkhani.

3 recordsLinked to original sources

A detail study of the LHC and TEVATRON hadron-hadron prompt-photon pair production experiments in the angular ordering constraint k_t-factorization approaches

In the present work, which is based on the k_-factorization framework, it is intended to make a detail study of the isolated prompt-photon pairs (IPPP) production in the high-energy inelastic hadron-hadron collisions differential cross section. The two scheme-dependent unintegrated parton distribution functions (UPDF) in which the angular ordering constraints (AOC) are imposed, namely the Kimber-Martin-Ryskin (KMR) and the Martin-Ryskin-Watt (MRW) approaches, in the leading and the next-to-leading orders (LO and NLO) are considered, respectively. These two prescriptions (KMR and MRW) utilize the phenomenological parton distribution functions (PDF) libraries of Martin et al, i.e. the MMHT2014. The computations are performed in accordance with the initial dynamics of latest existing experimental reports of the D0, CDF, CMS and ATLAS collaborations and the different experimental constraints. It is shown that above frameworks are capable of producing acceptable results, compared to the experimental data, the pQCD and some Monte Carlo calculations (i.e. 2γ-NNLO, SHERPA, DIPHOX and RESBOS). It is also concluded that the KMR framework produces better results in the higher center-of-mass energies, while the same thing can be argued about the LO-MRW prescription in lower energies. Additionally, these two schemes show different behavior in the regions where the fragmentation and higher pQCD effects become important. A clear prediction for the various shoulders and tails which were detected experimentally are observed and discussed in the present theoretical approaches. The possible double countings between 2 \rightarrow 2 and 2 \rightarrow 3 processes are studied.

hep-ph

LHC production of forward-center and forward-forward di-jets in the $k_t$-factorization $unintegrated$ parton distribution frameworks

The present work is devoted to study the high-energy $QCD$ events, such as the di-jet productions from proton-proton inelastic collisions at the $LHC$ in the forward-center and the forward-forward configurations, using the $unintegrated$ parton distribution functions ($UPDF$) in the $k_t$-factorization framework. The $UPDF$ of $Kimber$ et. al. ($KMR$) and $Martin$ et.al. ($MRW$) are generated in the leading order ($LO$) and next-to-leading order ($NLO$), using the $Harland-Lang$ et al. ($MMHT2014$) $PDF$ libraries. While working in the forward-center and the forward-forward rapidity sectors, one can probe the parton densities at very low longitudinal momentum fractions ($x$). Therefore, such a computation can provide a valuable test-field for these $UPDF$. We find very good agreement with the corresponding di-jet production data available from $LHC$ experiments. On the other hand, as we have also stated in our previous works, (i.e. the protons longitudinal and transverse structure function as well as hadron-hadron $LHC$ $W/Z$ production), the present calculations based on the $KMR$ prescriptions show a better agreement with the corresponding experimental data. This conclusion is achieved, due to the particular visualization of the angular ordering constraint ($AOC$), despite the fact that the $LO-MRW$ and the $NLO-MRW$ formalisms both employ better theoretical descriptions of the $Dokshitzer$-$Gribov$-$Lipatov$ -$Altarelli$-$Parisi$ ($DGLAP$) evolution equation, and hence are expected to produce better results. The form of the $AOC$ in the $KMR$ prescription automatically includes the re-summation of the higher-order $ln({1/x})$ type contributions, i.e. the $Balitski$-$Fadin$-$Kuraev$-$Lipatov$ ($BFKL$) logarithms, in the $LO$-$DGLAP$ evolution equation.

hep-ph

The $NLO$ production of the $W^{\pm}$ and $Z^0$ vector bosons via hadron collisions in the frameworks of $KMR$ and $MRW$ unintegrated parton distribution functions

In a series of papers, we have investigated the compatibility of the $Kimber$-$Martin$-$Ryskin$ ($KMR$) and $Martin$-$Ryskin$-$Watt$ ($MRW$) $unintegrated$ parton distribution functions ($UPDF$) as well as the description of the experimental data on the proton structure functions. The present work is a sequel to that survey, via calculation of the transverse momentum distribution of the electro-weak gauge vector bosons in the $k_t$-factorization scheme, by the means of the $KMR$, the $LO\;MRW$ and the $NLO\;MRW$ $UPDF$, in the next-to leading order ($NLO$). To this end, we have calculated and aggregated the invariant amplitudes of the corresponding $involved$ diagrams in the $NLO$, and counted the individual contributions in different frameworks. The preparation process for the $UPDF$ utilizes the $PDF$ of $Martin$ et al, $MSTW2008-LO$, $MSTW2008-NLO$, $MMHT2014-LO$ and $MMHT2014-NLO$ as the inputs. Afterwards, the results have been analyzed against each other, as well as the existing experimental data. Our calculation show excellent agreement with the experiment data. It is however interesting to point-out that, the calculation using the $KMR$ framework illustrates a stronger agreement with the experimental data, despite the fact that the $LO\;MRW$ and the $NLO\;MRW$ formalisms employ a better theoretical description of the $DGLAP$ evolution equation. This is of course due to the use of the different implementation of the angular ordering constraint in the $KMR$ approach, in which automatically includes the re-summation of $ln({1/x})$, $BFKL$ logarithms, in the $LO$-$DGLAP$ evolution equation.

hep-ph