Preprint Article Version 1 NOT YET PEER-REVIEWED

# Initial Energy Density of $sqrt$(s) = 7 and 8 TeV p+p Collisions at the LHC

1. Eötvös Loránd University, H – 1117 Budapest, Pázmány P. s. 1/A, Hungary
2. Wigner RCP, H – 1525 Budapest 114, POBox 49, Hungary
3. EKU KRC, H – 3200 Gyöngyös, Mátrai út 36
4. Central China Normal Universit, 152 Luoyu Road ,Wuhan, Hubei 430079, People’s Republic of China
Version 1 : Received: 4 October 2016 / Approved: 5 October 2016 / Online: 5 October 2016 (09:04:52 CEST)

Copyright: This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

How to cite: Csanad, M.; Csorgo, T.; Jiang, Z.; Yang, C. Initial Energy Density of $sqrt$(s) = 7 and 8 TeV p+p Collisions at the LHC. Preprints 2016, 2016100010 (doi: 10.20944/preprints201610.0010.v1). Csanad, M.; Csorgo, T.; Jiang, Z.; Yang, C. Initial Energy Density of $sqrt$(s) = 7 and 8 TeV p+p Collisions at the LHC. Preprints 2016, 2016100010 (doi: 10.20944/preprints201610.0010.v1).

## Abstract

Accelerating, exact, explicit and simple solutions of relativistic hydrodynamics allow for a simple and natural description of highly relativistic p+p collisions. These solutions yield a finite rapidity distribution, thus they lead to an advanced estimate of the initial energy density of high energy collisions. We show that such an advanced estimate yields an initial energy density in $\sqrt{s}=7$ and 8 TeV p+p collisions at LHC around or above the critical energy density from lattice QCD, and a corresponding initial temperature above the critical temperature from QCD and the Hagedorn temperature. This suggests that the collision energy of the LHC corresponds to a large enough initial energy density to create a non-hadronic perfect fluid even in pp collisions. %We also show, that several times the %critical energy density may have been reached in high multiplicity events, hinting at a non-hadronic medium created in %high multiplicity $\sqrt{s}=7$ and 8 TeV p+p collisions.

## Subject Areas

quark-gluon plasma, hydrodynamics, pseudorapidity distribution, initial state, energy density, Bjorken estimate