1. Investigation of Coherent Dissociation 10 C Nuclei at an Energy of 1.2 A GeV Mamatkulov Kahramon LHEP, JINR, Dubna JSPI, Uzbekistan EMIN’15 05-08 October 2015

2. Energy levels of 10 C Example of microphotograph

3. Amplitude spectrum from a scintillation counter, shows the positions of the peaks for nuclei with charges Z pr = 4, 6 and 7 Irradiation of the emulsion in the beam nuclei Be, C and N with energy 1.2 A GeV

4. Distribution of tracks beam nuclei by the number of δ-electrons N δ per 1 mm of the tracks length.  Viewed plates – 12 pcs.  The total length of viewing of primary tracks – 1088.1 m.  Number of total events – 7241  Number of events ("white stars“) – 608 Analysis of the primary beam

5. The charge topology of "white" stars Channels ( 10 С) N ws =227100%N tf =627100% 2He+2H18681.936157.6 He+4H125.316025.5 3He ( 2 3 Не + 4 Не )125.3152.4 6H94.0304.8 Be + He62.6172.7 B+H10.4121.9 Li+3H10.420.3 9 С+n--304.8 Distribution by channels of dissociation of "white" stars N ws and events with fragments of the target or born mesons N tr

6. Identification of the relativistic isotopes H and He Distribution of the fragments by value pβc of the "white" stars 10 C  2He + 2H. 3 He fragments from events of fragmentation 9 С  3 3 Не at 1.2 A GeV.

7. Rayleigh distribution for p and α   (p) = (51 ± 3) × 10 -3 rad   (α) = (17 ± 1) × 10 -3 rad by the statistical model   (p) ≈ 47× 10 -3 rad   (α) ≈ 19 × 10 -3 rad Angle distributions of fragments Distribution of the fragments of the polar of emission angle formed in the "white stars" 10 C → 2α + 2p. (dotted line - p, solid line - α fragments)

8. Angle Θ, mrad 10 С → 2α + 2p 9 Be → 2α + n 0 - 10.5, σ Θ, mrad 4.6 ± 0.2 1.9 ± 0.2 4.6 ± 0.3 2.2 ± 0.2 15.0 – 45.0 30.4 ± 0.9 8.2 ± 0.7 27.1 ± 0.9 5.7 ± 0.6 Distribution of “white” stars 10 С → 2α + 2p (solid line) and 9 Be → 2α + n (dotted line) by the value Θ 2α. Inset - the distribution of events in the area Θ n. Distribution parameters of “white” star 10 C→2α + 2p and 9 Be → 2α + n events by value opening angle of α-particle Θ 2α.

9. Decays of unstable nuclei and rare events Formation of nuclei 9 B = (63 ± 30) keV, RMS = 83 keV = (254 ± 18) keV, RMS = 96 keV The distribution of "white" stars 10 C→2α+2p by excitation energy Q 2α pairs α-particles; inset - increased distribution Q 2α (a); distribution of events Q 2αp triples 2a + p; inset - increased distribution Q 2αp (b).

10. Rayleigh distribution  Pt ( 9 В) = (92  15) МeV/c by the statistical model  Pt ( 9 В) =93 MeV/c 10 С → 9 В + р → 8 Ве + 2р → 2α + 2р (30%) Distribution of the total transverse momentum P T2αp triple 2α+p from decays of 9 B nuclei in "white" stars 10 C → 2α + 2p; curve – statistical model.

11. Distribution by the angle of emission of the nuclei 9 B in «white» stars 10 С → 2α + 2р. Cases of scattering nuclei 9 B = 9.2 ± 0.8 mrad, RMS = 6.2 ± 0.6 mrad Condition θ 9B <13 mrad: = 6.7 ± 0.4 mrad, RMS = 3.1 ± 0.3 mrad

12. The three-dimensional picture of the direction of emission of the nucleus 9 B (2α + p) at large angles in the "white" stars 10 C → 9 B + p (event № 602-04-11).

13. Reflection of the nuclear resonances Distribution on the opening angle between α-particles Θ 2α and pairs αp Θ αp in «white» stars 10 С → 2α + 2p.

14. Distribution of energy pairs α-particle Q 2α and triple α2p Q α2p in «white» stars 10 С→2α + 2p. Interpretation of share of statistics related to resonances 5 Li and 6 Be, is indicative and may serve as upper evaluation for future research.

15. Dissociation of deep bound states Distribution by channels of dissociation of «white» stars N ws. Channels ( 10 С) N ws =227100% He+4H125.3 3He ( 2 3 Не + 4 Не )125.3 6H94.0 Be + He62.6 B+H10.4 Li+3H10.4

16. Conclusions  Performed search of nuclear stars in the length of about 1088 meters in the layers of nuclear emulsions irradiated in a mixed beam, configured on the separation of relativistic nuclei 12 N, 10 C and 7 Be. Identification of the charges of the beam nuclei and the fragments allowed to select 227 events dissociation of carbon, not accompanied by the formation of fragments of the target and mesons.  Established that a channel with two helium nuclei, and two hydrogen (2He + 2H) is 82%. Leading these channel corresponds to representations of the structure exactly the isotope 10 C, and confirms the correctness of the beam. Among isotopes of He and H, identified by multiple scattering are present only 4 He and 1 H, that also corresponds to the dominance of the isotope 10 C in the beam. On this basis, 184 events in this channel pair interpreted as alpha particles and protons ( 10 C → 2α + 2p).  Done measurements of the polar and azimuthal angles of fragments, and also independent measuring angles scattering fragments in 184 events of coherent dissociation 10C → 2α + 2p. Create an array of measurement uses for complex analysis of the angular correlations fragments.

17.  Established that in the distribution of the invariant mass, 60 triples fragments 2α + p correspond to the cascade decay of the nucleus 9 B through the nucleus 8 Be. Thus, in the structure of the nucleus 10 C with probability not less than 30 % manifested unstable nucleus 9 B, and unstable nucleus 8 Be manifests itself only as a component of 9 B. This conclusion is confirmed by the distribution of the total transverse momentum of the nuclei 9 B, which in the main part described by the Rayleigh distribution with parameter (92 +15) MeV/c, corresponding to statistical model. Were found 10 events scattering nucleus 9B out of the fragmentation cone.  Discovered a rare event dissociation, indicating the existence in the nucleus 10 C is deeply related cluster states 7 Be + 3 He and 2 3 He + 4 He with a weight of 8%. With a probability 4% observed events fully coherent dissociation of 10 C nuclei to six hydrogen nuclei.

18. Thank you for attention!