0000000001171262
AUTHOR
Mikko Kuha
Evidence of shadowing in inelastic nucleon-nucleon cross section
The Glauber modeling plays a key role in centrality-dependent measurements of heavy-ion collisions. A central input parameter in Glauber models is the inelastic nucleon-nucleon cross section $\sigma_{\text{nn}}^{\text{inel}}$ which is nearly always taken from proton-proton measurements. At the LHC energies $\sigma_{\text{nn}}^{\text{inel}}$ depends on the QCD dynamics at small $x$ and low interaction scales where the shadowing/saturation phenomena are expected to become relatively more important for larger nuclei than for the proton. Thus, $\sigma_{\text{nn}}^{\text{inel}}$ e.g. in Pb+Pb collisions may well be lower than what is seen in proton-proton collisions. In this talk, we demonstrate…
Shadowing in Inelastic Nucleon-Nucleon Cross Section?
Experimental results of inclusive hard-process cross sections in heavy-ion collisions conventionally lean on a normalization computed from Glauber models where the inelastic nucleon-nucleon cross section $\sigma_{\rm nn}^{\rm inel}$ -- a crucial input parameter -- is simply taken from proton-proton measurements. In this letter, using the computed electro-weak boson production cross sections in lead-lead collisions as a benchmark, we determine $\sigma_{\rm nn}^{\rm inel}$ from the recent ATLAS data. We find a significantly suppressed $\sigma_{\rm nn}^{\rm inel}$ relative to what is usually assumed, show the consequences for the centrality dependence of the cross sections, and address the phe…
Eikonal minijet model for proton-proton collisions
Tässä tutkielmassa johdettiin minijettimalli suurienergiaisille protoni-protoni -törmäyksille eikonaaliformalismissa. Mallia testattiin numeerisen laskennan keinoin kokeellisilla tuloksilla protoni-protoni -törmäyksien elastisista, epäelastisista ja kokonaisvaikutusaloista keskeisliikemääräkoordinaatiston energiaskaalassa sqrt(s)=0.1..100 TeV. Myös viimeisimpiä CERN-LHC -kiihdyttimen mittaustuloksia tarkasteltiin. Numeerisen analyysin yhtenä osana tutkittiin myös yhden efektiivisen aliprosessin approksimaatiota, joka osoittautui tutkituilla energioilla hyvin tarkaksi. Lisäksi tarkasteltiin moninkertaisen kaksijettituoton roolia protoni-protoni -törmäysten epäelastisessa vaikutusalassa. An e…