Measurement of the strong-interaction shift and broadening of the ground state of the pp̄ atom

Academic Article


  • The Kα X-rays from pp̄ atoms formed in H2 gas at normal temperature and pressure are unambiguously identified by coincidences with L X-rays populating the 2P level. Background due to inner bremsstrahlung is suppressed by selecting events annihilating into neutral final states only. The Kα line is observed with a significance of more than 25 standard deviations at an energy of 8.67 (15) keV. From fits to the Kα line we obtain a strong-interaction shift and width of the 1S level, averaged over the unresolved spin singlet and triplet contributions, of ΔE + iΓ/2 = [-0.70(15) + i0.80(20)] keV. © 1988.
  • Authors

    Published In

  • Physics Letters B  Journal
  • Digital Object Identifier (doi)

    Author List

  • Ziegler M; Ahmad S; Amsler C; Armenteros R; Auld EG; Axen DA; Bailey D; Barlag S; Beer GA; Bizot JC
  • Start Page

  • 151
  • End Page

  • 158
  • Volume

  • 206
  • Issue

  • 1