Naslov
Observation of Two-source Interference in the Photoproduction Reaction Au Au --> Au Au rho(0)

Autori
Abelev, B.I. ; ... ; Planinić, Mirko ; ... ; Poljak, Nikola ; et al. (the STAR Collaboration)

Izvornik
Physical Review Letters (0031-9007) 102 (2009), 11; 112301-112307

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
ultra-peripheral relativistic heavy-ion collisions

Sažetak
In ultra-peripheral relativistic heavy-ion collisions, a photon from the electromagnetic field of one nucleus can fluctuate to a quark-antiquark pair and scatter from the other nucleus, emerging as a $\rho^0$. The $\rho^0$ production occurs in two well-separated (median impact parameters of 20 and 40 fermi for the cases considered here) nuclei, so the system forms a 2-source interferometer. At low transverse momenta, the two amplitudes interfere destructively, suppressing $\rho^0$ production. Since the $\rho^0$ decay before the production amplitudes from the two sources can overlap, the two-pion system can only be described with an entangled non-local wave function, and is thus an example of the Einstein-Podolsky-Rosen paradox. We observe this suppression in 200 GeV per nucleon-pair gold-gold collisions. The interference is $87% \pm 5% {; ; \rm (stat.)}; ; \pm 8%$ (syst.) of the expected level. This translates into a limit on decoherence due to wave function collapse or other factors, of 23% at the 90% confidence level.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

Napomena
Art. no. 112301

POVEZANOST RADA