English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We argue that ultrahigh energy cosmic ray collisions in the Earth atmospherecan probe the strange quark density of the nucleon. These collisions havecenter-of-mass energies \agt 10^{4.6} A GeV, where A \geq 14 is the nuclearbaryon number. We hypothesize the formation of a deconfined thermal fireballwhich undergoes a sudden hadronization. At production the fireball has a veryhigh matter density and consists of gluons and two flavors of light quarks(u,d). Because the fireball is formed in the baryon-rich projectilefragmentation region, the high baryochemical potential damps the production ofu \bar u and d \bar d pairs, resulting in gluon fragmentation mainly into s\bar s. The strange quarks then become much more abundant and uponhadronization the relative density of strange hadrons is significantly enhancedover that resulting from a hadron gas. Assuming the momentum distributionfunctions can be approximated by Fermi-Dirac and Bose-Einstein statistics, weestimate a kaon-to-pion ratio of about 3 and expect a similar (total)baryon-to-pion ratio. We show that, if this were the case, the excess ofstrange hadrons would suppress the fraction of energy which is transferred todecaying \pi^0's by about 20\%, yielding a \sim 40\% enhancement of the muoncontent in atmospheric cascades, in agreement with recent data reported by thePierre Auger Collaboration.

Strange fireball as an explanation of the muon excess in Auger data