ELECTROMAGNETIC COMEX5 IN PHOTOABSORPTION REACTIONS AND IN UPC. Mariola Kłusek-Gawenda

Transcription

1 ELECTROMGNETIC EXCITTION OF IN PHOTOBSORPTION RECTIONS ND IN UPC MRIOL K-G EP EXCITTION OF Mariola Kłusek-Gawenda Niewodniczański Institute of Nuclear Physics Polish cademy of Sciences, Kraków, Poland MRIOL K-G (KRKÓW) KRKÓW, / 3

2 ELECTROMGNETIC EXCITTION OF Heavy ion collision photons fluxes [v c] Photon nucleus excitation MRIOL K-G EP 1 De-excitation system breakup neutron emission 1 n 1 Meson production with neutron emission 1 1 n n n n EXCITTION OF X X 1 X MRIOL K-G (KRKÓW) KRKÓW, / 3

3 EP EQUILENT PHOTON PPROXIMTION MRIOL K-G R 1 The strong electromagnetic field is a source of photons that can induce electromagnetic reactions in ion-ion collisions. EP EXCITTION OF b ULTRPERIPHERL COLLISIONS R b > R min = R 1 + R b 1 b b MRIOL K-G (KRKÓW) KRKÓW, / 3

4 EP EM EXCITTION IN UPC 1 1 MRIOL K-G Single E EP σ ( 1 1 ) = d b P surv (b)p exc (b) Mutual 1 (E = E) 1(E1 = E 1) E 1 E EXCITTION OF σ ( 1 1 ) = d b P surv (b)p exc P surv (b) θ ( b (R 1 + R )) P exc (b) = n (b) exp [ n (b) ] n (b) = de N 1 (E, b)σ tot (γ ; E) E min (b)p exc 1 (E = E ) (b) MRIOL K-G (KRKÓW) KRKÓW, / 3

5 EP N(E, b) = Z α em π RELISTIC F(q) = 4π q ρ (r) sin (qr) rdr F(q) u 5 08 Pb Form factor u J 1 (u) Realistic Monopole q [Ge] F ( ( Eb γ ) +u b ( ) Eb +u γ ) MONOPOLE F(q) = Λ = Λ Λ +q 6 <r > 197 u Λ = 91 Me, 08 Pb Λ = 88 Me. < r > = 5.3 fm, < r > = 5.5 fm, In the literature: Λ = (80 90) Ge POINT-LIKE F(q) = 1 MRIOL K-G EP EXCITTION OF MRIOL K-G (KRKÓW) KRKÓW, / 3

6 EP uu uu µ + µ MRIOL K-G )/db [nb/fm] µ + dσ(uu uuµ s NN = 00 Ge F realistic F monopole b [fm] ) )/dσ(f dσ(f monopole realistic 1 s 0.9 NN = 00 Ge b [fm] EP EXCITTION OF MRIOL K-G (KRKÓW) KRKÓW, / 3

7 EXCITTION OF u) [mb] γ 197 u & γ 08 Pb Pb) [mb] 08 3 MRIOL K-G EP σ(γ σ(γ EXCITTION OF 3 E [Me] E [Me] 4 5 σ γ = σ GDR + σ QD + σ nucleon res. + σ nucleon cont. 1. E γ < 40 Me - σ GDR. E γ = (40 0) Me - σ QD 3. E γ = (0 00) Me - σ nucleon resonances 4. E γ = (1 8) Ge - σ low energy nucleon continuum 5. E γ > 8 Ge - σ high energy nucleon continuum MRIOL K-G (KRKÓW) KRKÓW, / 3

8 EXCITTION OF PROBBILITY OF NEUTRON MULTIPLICITY MRIOL K-G P k (E*) E* [Me] 197 u 0n 1n n 3n 4n 5n 6n 7n 8n 9n n fit sum: GEMINI fit P k (E*) E* [Me] 08 Pb 0n 1n n 3n 4n 5n 6n 7n 8n 9n n fit sum: GEMINI fit EP EXCITTION OF GEMINI++ evaporation process is described by the Hauser-Feshbach formalism More details back-up slides MRIOL K-G (KRKÓW) KRKÓW, / 3

9 EXCITTION OF γ u/ Pb 1n ( 1) u/ Pb MRIOL K-G EP u) [mb] 196 u 1n 197 σ(γ (γ,n) (γ,n)+(γ,n+p) Pb) [mb] 07 Pb 1n 08 σ(γ (γ,n) (γ,n)+(γ,n+p) EXCITTION OF E γ [Me] E γ [Me] MRIOL K-G (KRKÓW) KRKÓW, / 3

10 EXCITTION OF γ u/ Pb n ( ) u/ Pb MRIOL K-G EP u) [mb] 195 u n 197 σ(γ (γ,n) (γ,n)+(γ,n+p) Pb) [mb] 06 Pb n 08 σ(γ (γ,n) (γ,n)+(γ,n+p) EXCITTION OF E γ [Me] E γ [Me] MRIOL K-G (KRKÓW) KRKÓW, / 3

11 EXCITTION OF γ u/ Pb 3n ( 3) u/ Pb MRIOL K-G EP u) [mb] 194 u 3n 197 σ(γ (γ,3n) 1970 Pb) [mb] 05 Pb 3n 08 σ(γ (γ,3n) 1970 EXCITTION OF E γ [Me] E γ [Me] MRIOL K-G (KRKÓW) KRKÓW, / 3

12 MRIOL K-G EP EXCITTION OF FIG. ZN energy spectrum requiring signal over threshold in ZN but not in ZNC, rejecting thus neutron emission on the opposite side. The dashed lines represent the single fits of the different peaks (1n, n,...), while the continuous line is the sum of all the contributions. P. Cortese, International Conference on New Frontiers in Physics 01 MRIOL K-G (KRKÓW) KRKÓW, / 3

13 IN UPC MRIOL K-G s NN = 130 Ge σ(uu uu*) [b] 0 ours s NN = 130 Ge σ(pbpb PbPb*) [b] s NN =.76 Te 0 ours s NN =.76 Te LICE EP EXCITTION OF kn given multiplicity of neutrons single-nucleus, single-photon excitation n 1n kn LICE= (.5 ± 0.5 (stat) ±0.9 (syst))% ours= 1.6% MRIOL K-G (KRKÓW) KRKÓW, / 3

14 IN UPC MRIOL K-G EP σ EMD (uu uu*) [b] 3 SPS total 1n n σ EMD (PbPb PbPb*) [b] 3 SPS LICE total 1n n EXCITTION OF 1 s NN [Ge] 3 1 s NN [Ge] 3 MRIOL K-G (KRKÓW) KRKÓW, / 3

15 S Cross section (in barns) for s NN = 130 Ge 1n n 3n 4n 5n 6n 1n n n n n n MRIOL K-G EP EXCITTION OF MRIOL K-G (KRKÓW) KRKÓW, / 3

16 S Cross section (in barns) for s NN = 130 Ge 1n1.6 n 3n ours 4n 5n 6n 1n PHENIX n PHOBOS BRHMS 3n Baltz et al. 4n et al. 5n {Pshenichnov n σ(1,x) σ(1,1) σ(,x) 0.6 σ(uu u*u*) [b] 0.4 } } MRIOL K-G EP EXCITTION OF 0. 0 s NN = 130 Ge (kn,kn) MRIOL K-G (KRKÓW) KRKÓW, / 3

17 S MRIOL K-G σ( **) [b] ours RHIC LHC EP EXCITTION OF 3 3 s NN MRIOL K-G (KRKÓW) KRKÓW, / 3

18 PPLICTION TO EXCLUSIE PROCESSES MRIOL K-G IP/IR IP/IR 1 γ γ 1 X1 X EP ρ 0 ( π + π ) J/ψ ρ 0 ρ 0 ( 4π) l + l EXCITTION OF IP/IR IP/IR IP/IR IP/IR IP/IR IP/IR IP/IR IP/IR ρ 0 ρ 0 ( π + π π + π ) J/ψJ/ψ MRIOL K-G (KRKÓW) KRKÓW, / 3

19 ρ 0 PRODUCTION IN HEY ION UPC WITH NUCLER EXCITTION 1 n MRIOL K-G 1 ρ 0 EP n STR data stat. error syst. error our results s NN =130 Ge EXCITTION OF ) [mb] σ(uu u*u*ρ very preliminary 0 XnXn 0nXn 1n1n 0n0n total MRIOL K-G (KRKÓW) KRKÓW, / 3

20 S Impact parameter space approach Neutron emission Hauser-Feshbach formalism Good description of experimental data for the excitation functions for γ+ 197 u and γ+ 08 Pb photoabsorption + giant resonances + quasi-deuteron + excitation of nucleon resonances + breakup of nucleon with fixed number of neutrons UPC heavy-ion collision (RHIC and LHC energy) single mutual excitations Reference: M. K-G, M. Ciemała, W. Schäfer and. Szczurek, Phys. Rev. C89 (014) , Electromagnetic excitation of nuclei and neutron evaporation in ultrarelativistic ultraperipheral heavy ion collisions MRIOL K-G EP EXCITTION OF uu u u ρ 0 (770) - theory & experiment MRIOL K-G (KRKÓW) KRKÓW, / 3

21 S [µb] dσ/dy J/Ψ not only UPC PbPb PbPbJ/ψ (0) N (ω,b) (1) N (ω,b) () N (ω,b) (a) (b) b 1 b 1 b b b b MRIOL K-G EP EXCITTION OF centrality [%] Reference: M. K-G and. Szczurek, arxiv: [nucl-th], Photoproduction of J/ψ mesons in peripheral and semi-central heavy ion collisions LICE data: talk given by Laura Massacrier at EDS Blois workshop, 9th June - 4th July 015, Borgo, Corsica, France MRIOL K-G (KRKÓW) KRKÓW, / 3

22 MRIOL K-G EP Back-up slides EXCITTION OF MRIOL K-G (KRKÓW) KRKÓW, / 3

23 DECYS OF EXCITED NUCLER SYSTEM S 1 CN +S d J+S i Γ i = πρ(e dɛ T l (ɛ)ρ(e B i ɛ, S d ), (1), S CN ) S d =0 J= S CN S d l= J S i where S d is the spin of the daughter nucleus, S i, J and l are spin, total and angular momentum of the evaporated particle, ɛ, B i are kinetic and separation energies, T l is its transmission coefficient, ρ and ρ CN are level densities of the daughter and compound nucleus, which can be calculated from the formula: ( ) ρ(e, S) (S + 1) exp a(u, S)U, () where U = E E rot (S) δp is thermal excitation energy calculated by taking into account pairing corrections to the empirical mass formula (δp) and rotational energy E rot (S). Level density parameter a(u, S) was calculated as: ( a(u, S) = ã(u) 1 h(u/η + S/S δw ) η), (3) U where δw is the shell correction to the liquid-drop mass and ã is smoothed level-density parameter, the function specifying the rate of fadeout is h(x) = tanh x, the fadeout parameter η was set to 18.5 Me and the parameter S η was set to 50. The smoothed level density parametrization depends on the excitation energy of nucleus as: MRIOL K-G EP EXCITTION OF ã(u) = ( ), (4) k (k k 0 ) exp k k κ U 0 where k 0 = 7.3, k = 1 and κ = exp(0.0345). MRIOL K-G (KRKÓW) KRKÓW, / 3