1. 3-12-2004 NIKHEFFokke de Boer1 anomalous internal pair conversion as a sign for elusive light neutral particles e+e+ e–e–

2. 3-12-2004 NIKHEFFokke de Boer2 anomalous internal pair conversion as a sign for elusive light neutral particles e+e+ e–e–

3. 3

4. 3-12-2004 NIKHEF4 co-authors Johan van Klinken 1 Helmut Bokemeyer 2 Klaus Bethge 3 Oliver Fröhlich 3 Alkis Müller 3 Kurt Stiebing 3 Margo Csatlós 4 Zoltan Gácsi 4 Janos Gulyás 4 Mathias Hunyadi 4 Attila Krasznahorkay 4 Zoltan Máté 4 René van Dantzig 5 Tjeerd Ketel 5 1 Groningen 2 Darmstadt 3 Frankfurt 4 Debrecen 5 Amsterdam

5. 3-12-2004 NIKHEF5 light neutral particles upper limits in emulsions in nuclear transitions spectroscopy and dark matter branching ratios 511 keV radiation pair production anomalous IPC fantasy

6. 3-12-2004 NIKHEF6 candidate bosons olight Higgs (0 + ) to explain muonic X-rays anomalies Watson and Sundaresan (1971) oaxion, a light pseudoscalar boson (0 - ) invented to prevent large CP-violations, Peccei and Quinn (1978) oU-boson a supersymmetric gauge boson (1 +, 1 - ), Fayet (1981)

7. 3-12-2004 NIKHEF7 particle data book

8. 3-12-2004 NIKHEF8 allowed window (not for T=1 axions)

9. 3-12-2004 NIKHEF9 emulsion events

10. 3-12-2004 NIKHEF10

11. 3-12-2004 NIKHEF11

12. 3-12-2004 NIKHEF12 spin-parity conservation.

13. 3-12-2004 NIKHEF13 width

14. 3-12-2004 NIKHEF14 correlation angle ω (degrees) number of IPC pairs (a.u.)

15. 3-12-2004 NIKHEF15 detector array

16. 3-12-2004 NIKHEF16

17. 3-12-2004 NIKHEF17 studied reactions

18. 3-12-2004 NIKHEF18 alpha nuclei

19. 3-12-2004 NIKHEF19 agreement with E1-IPC in 12 C

20. 3-12-2004 NIKHEF20 agreement with IPC in 12 C and a deviation in 8 Be Phys.Lett. B388 (1996) 235 7 Li(p,  ) 8 Be 1 +, T=1, 17.6 MeV 11 B(p,  ) 12 C 1 -, T=1, 17.2 MeV

21. 3-12-2004 NIKHEF21 isoscalar decay from 18.15 MeV in 8 Be

22. 3-12-2004 NIKHEF22 results from IKF, KVI and SUNY branching ratios and widths an isoscalar boson scenario with mass of 9 MeV/c 2, with spin 0 - or 1 +, and coupling strength α X proportional to the isoscalar width in the magnetic transition.

23. 3-12-2004 NIKHEF23 KVI annual report 2002

24. 3-12-2004 NIKHEF24 16 O (0 -,T=0) 10.96 MeV decay

25. 3-12-2004 NIKHEF25 To be published in Phys. Rev. Lett. 16 O (0 -,T=0) 10.95 MeV decay (M0 transition !!)

26. 3-12-2004 NIKHEF26 boson search program

27. 3-12-2004 NIKHEF27 8 Be (1 +,T=1) 17.64 MeV decay

28. 3-12-2004 NIKHEF28 8 Be (1 +,T=0) 18.15 MeV decay

29. 3-12-2004 NIKHEF29 16 O (0 -,T=0) 10.96 MeV decay

30. 3-12-2004 NIKHEF30 12 C (1 +,T=0) 12.71 MeV decay

31. 3-12-2004 NIKHEF31 12 C (1 +,T=1) 17.23 MeV decay

32. 3-12-2004 NIKHEF32 16 O (0 +,T=0) 6.05 MeV decay

33. 3-12-2004 NIKHEF33 16 O 6.05, 8.87, and 10.96 MeV decay

34. 3-12-2004 NIKHEF34

35. 3-12-2004 NIKHEF35

36. 3-12-2004 NIKHEF36 SPI data are consistent with positrons that originate from centre of the Galaxy and either: low-mass X-ray binaries, novae, type I a supernovae, or possibly light dark matter. INTEGRAL satellite

37. 3-12-2004 NIKHEF37

38. 3-12-2004 NIKHEF38 summary anomalous internal pair conversion is observed in isoscalar nuclear transitions magnetic monopole transition in 16 O is found several candidates for isoscalar neutral bosons in the 2-15 MeV mass region are reported one of the vector boson candidates may be the U-boson and be intermediate in the annihilation of light dark matter