LHC production of forward-center and forward-forward di-jets in the k-factorization and transverse dependent unintegrated parton distribution frameworks

Abstract

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 forwardforward configurations, using the unintegrated parton distribution functions (U P DF ) in the k tfactorization framework. The U P DF of Kimber et. al. (KM R) and M artin et.al. (M RW ) are generated in the leading order (LO) and next-to-leading order (N LO), using the Harland − Lang et al. (M M HT 2014) P DF 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 U P DF . 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 KM R 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−M RW and the N LO−M RW formalisms both employ better theoretical descriptions of the Dokshitzer-Gribov-Lipatov -Altarelli-P arisi (DGLAP ) evolution equation, and hence are expected to produce better results. The form of the AOC in the KM R prescription automatically includes the re-summation of the higher-order ln(1/x) type contributions, i.e. the Balitski-F adin-Kuraev-Lipatov (BF KL) logarithms, in the LO-DGLAP evolution equation. PACS numbers: 12.38.Bx, 13.85.Qk,

Three-photon productions within the $$k_t$$-factorization at the LHC

“…They also extends the LO-MRW approach to the NLO level (NLO-MRW). One can find a detailed investigation of these UPDFs in the references [19][20][21], and also effects of using these UPDFs in cross section calculations are discussed in the references [22][23][24][25][26][27][28][29][30].…”

A validity check of the KATIE parton level event generator in the $k_t$-factorization and collinear frameworks

“…As it can be seen in this figure, the result of the k t -factorization with the LO-MRW and NLO-MRW UPDFs are strangely off the data. Because, in the previous works, It was shown that the MRW UPDFs can produce the corresponding data reasonably [26][27][28][29][30][31][32][33][34], so to be sure what makes our calculation to get worse, we evaluated the differential cross section within the collinear factorization framework, using the MMHT2014nlo68cl PDFs. The prediction of the collinear factorization, as depicted in the left panel of figure 1, convinces us that there should be something wrong with this parton level event generator [3].…”

“…Another approach for defining UPDFs is the Martin-Ryskin-Watt (MRW) approach [17,18] which assumes parton evolves according to the DGLAP evolution equations [12][13][14] till the last parton emission, and then it resums the no-emission parton probability to the hard factorization scale via the Sudakov form factor. This method is investigated in detail [19][20][21][22][23][24][25] and is shown to be successful in describing the data of different processes at the LHC, Tevatron etc [26][27][28][29][30][31][32][33][34].…”

A detailed study of charm content of a proton in the frameworks of the Kimber-Martin-Ryskin and Martin-Ryskin-Watt approaches

“…In our previous articles, we investigated the general behavior and stability of the KM R and M RW schemes [19][20][21][22][23][24][25][26][27]. Also, we have successfully used KM R-U P DF to calculate the inclusive production of the W and Z gauge vector bosons [28,29], the semi-N LO production of Higgs bosons [30], the production of forward-center and forward-forward di-jets [31], the prompt-photon pair production [32] and recently in the reference [33], we explored the phenomenology of the integral and the differential versions of the KM R-U P DF using the angular (strong) ordering (AOC (SOC)) constraints. But here, to check the reliability of generated U P DF , we use them to calculate the observable, deep inelastic scattering the charm structure functions (F cc 2 (x, Q 2 )).…”