Pentaquarks search in NOMAD
Existence of pentaquarks - hadrons build of 4 quarks and one anti-quark was predicted in a brilliant paper by Dmitry Diakonov, Viktor Petrov and Maxim Polyakov .
Many experiments looked for these new states. Some of them found, some did not.
The NOMAD experiment also took a part in this race. The road was not easy...
In 2004 our report claimed for an evidence for the state based on a sample with cleaner protons loosing however 6 times in the final statistics. However later we realized that in a less pure sample we must see pentaquarks even more clearly and we performed this time a blind analysis maximazing the sensitivity to the pentaquark state. The abstract of our article accepted for Eur.Phys.C reads:
A search for exotic baryon via decay mode in the NOMAD data is reported. The special background generation procedure was developed. The proton identification criteria are tuned to maximize the sensitivity to the signal as a function of which allows to study the production mechanism. We do not observe any evidence for the state in the NOMAD data. We provide an upper limit on production rate at 90% CL as per neutrino interaction.
The article is posted to hep-ex/0612063 archive.
The full list of our presentations on the subject can be found here:
- NOMAD meeting on December 2004, by Dmitry Naumov
- NOMAD meeting on December 2005, by Dmitry Naumov
- XXVIII WorkShop "Neutrino Physics on Accelerators" on January, 25th, 2006, by Oleg Samoylov
- ITEP Seminar on April, 12th, 2006, by Dmitry Naumov
- ICHEP Presentation on August 2006, by Vincenzo Cavasinni
- Poster by Oleg Samoylov
- HADRON07 Presentation on October 2007, by Oleg Samoylov
Dmitry Naumov had a pleasure to meet all three penta-classics together in Bochum in house of Maxim Polyakov October 2006.here.