Four-jet double parton scattering production in proton-nucleus collisions within the pythia8 framework

DPS mechanism for associated $$c\bar{c} b\bar{b}$$ production in AA UPCs

“…We observe an approximately linear enhancement of this ratio in A at large A, in overall consistency with simulations of the inclusive DPS cross section off proton versus nuclear targets found recently in Ref. [13]. However, the growth in UPCs is steeper, since here the target gluons are probed by projectile photons that are more spread than projectile gluons and thus are more dependent on the size of target.…”

“…Most common examples with a significant DPS effect include meson pairs [10], four identified jets [11] or leptons [12] etc. In fact, the MPIs are naturally accounted for in most commonly used event generators [3,13].…”

Two-loop splitting in double parton distributions

“…There is also a large body of phenomenological work on such processes. An example is the recent study [28] of four-jet production, which also contains a wealth of further references. For a detailed account of theoretical and experimental aspects of DPS, we refer to the monograph [29].…”

Combining single and double parton scatterings in a parton shower

“…The importance of DPS relative to SPS increases with collider energy (as lower momentum fractions are probed, where the population of partons is greater), such that DPS is more relevant at the Large Hadron Collider (LHC) than at any previous collider, and will be yet-more relevant at any future higher-energy protonproton collider. DPS can also be an important effect in proton-nucleus and nucleus-nucleus collisions, with certain contributions to DPS rising more quickly with the nucleon number A than SPS does [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] (for a review, see [25]). Finally, DPS reveals information about the proton structure that is not accessible via any SPS process -namely, correlations between partons.…”