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Measurement of Anti-Deuteron Photoproduction and a Search for Heavy Stable Charged Particles at HERA

H1 Collaboration
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Abstract

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 < p_T/M < 0.7 and |y| < 0.4, where M, p_T and y are the mass, transverse momentum and rapidity in the laboratory frame of the anti-deuteron, 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 \pm 0.002 \pm 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.

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H1 Collaboration. 2004-03-31. Measurement of Anti-Deuteron Photoproduction and a Search for Heavy Stable Charged Particles at HERA. https://doi.org/10.1140/epjc%2Fs2004-01894-1

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