Measurement of anti-deuteron photoproduction and a search for heavy stable charged particles at HERA
par Aktas, Adil;Favart, Laurent 
;Janssen, Xavier ;Marage, Pierre ;Roland, Benoît ; [et al.]
Référence European Physical Journal C. Particles and Fields, 36, 4, page (413-423)
Publication Publié, 2004
;Janssen, Xavier ;Marage, Pierre ;Roland, Benoît ; [et al.]Référence European Physical Journal C. Particles and Fields, 36, 4, page (413-423)
Publication Publié, 2004
Article révisé par les pairs
| Résumé : | The cross section for anti-deuteron photoproduction is measured at HERA at a mean centre-of-mass energy of W γp = 200 GeV in the range 0.2 < pT/M < 0.7 and y < 0.4, where M, pT and y are the mass, transverse momentum and rapidity of the anti-deuteron in the HERA laboratory frame, respectively. The numbers of anti-deuterons per event are found to be similar in photoproduction to those in central proton-proton collisions at the CERN ISR but much lower than those in central Au-Au collisions at RHIC. The coalescence parameter B 2, which characterizes the likelihood of anti-deuteron production, is measured in photoproduction to be 0.010 ± 0.002 ± 0.001, which is much higher than in Au-Au collisions at a similar nucleon-nucleon centre-of-mass energy. No significant production of particles heavier than deuterons is observed and upper limits are set on the photoproduction cross sections for such particles. © Springer-Verlag / Società Italiana di Fisica 2004. |
