Geometrical scaling in inelastic inclusive particle production at the LHC

WG2 Highlights: Small-x, Diffraction and Vector Mesons

“…There was one talk in WG 2 on expanding the scope of observation of geometric scaling in the data. The work of M. Praszalowicz [68] reconfirmed the existing observation of geometric scaling in the HERA data on F 2 structure function and extended the scaling region up to fairly large x of 0.08. This is illustrated in Fig.…”

Geometrical scaling of prompt photons in heavy ion collisions

“…We can see from Fig. 1 that, indeed, heavy ion data scale according to (6) up to √ τ ∼ 1.8 approximately. The quality of scaling is, however, not as good as in the case of pp scattering [5].…”

“…We see that different distributions from the left panel coincide over some range of √ τ when scaled according to Eq. (6). For clarity in Fig.…”

“…However, multiplicity spectra scale with a somewhat lower power λ than the one extracted from DIS. We have argued that for pp scattering, where one does not control the overlap area transverse to the center of mass reaction axis, the quantity that scales with λ ≈ 0.33 is the differential cross section, rather than multiplicity [6]. This should be contrasted with the heavy ion (HI) reactions, when the transverse overlap area is controlled by an appropriate choice of centrality classes.…”

Saturation and geometrical scaling: from small x DIS to high energy heavy ion collisions

“…In Ref. [14] we argue that this difference is removed if one assumes that the scaling observable is dσ rather that dN, which implies that the proportionality factor in Eq. (2.5) is not energy independent S ⊥ but an inelastic cross-section σ in (s).…”