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Separation of Flip and Non-Flip parts of np→pn (0º) Charge Exchange reaction at energies 0.55 – 2.0 GeV R.A. Shindin NN formalism and Charge Exchange process.

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Presentation on theme: "Separation of Flip and Non-Flip parts of np→pn (0º) Charge Exchange reaction at energies 0.55 – 2.0 GeV R.A. Shindin NN formalism and Charge Exchange process."— Presentation transcript:

1 Separation of Flip and Non-Flip parts of np→pn (0º) Charge Exchange reaction at energies 0.55 – 2.0 GeV R.A. Shindin NN formalism and Charge Exchange process R dp measurements and tools Dean formula and Luboshitz remark Goldberger-Watson amplitudes and the Flip and Non-Flip parts of np-elastic scattering Delta-Sigma experimental data of the ratio R dp at 0°, respective values of the ratio r nf/fl and good agreement with the Phase Shift Analysis

2 np interaction in the c.m.s. Elastic backward Charge Exchange forward These both cases have identical cinematic and therefore can`t be separated using experiment – t = P 2 CM · (1– 4sin 2 Q/2) – t = P 2 CM · 4sin 2 Q/2

3 Born approach Enrico Fermi, in book Yadernaya Fizika 1951

4 NN formalism General view of the NN scattering matrix If both nucleons are identical then For the np elastic scattering we have For the Charge Exchange

5

6 According to the antisymmetry of two fermions wave function relative to the total permutation, including permutation of scattering vector (k`→ –k` ), permutation of spin and isotopic-spin (n↔p), we define

7 Charge-Exchange np→pn(θ)

8 R dp measurements and tools The Delta-Sigma experiment intends to obtain a complete np data set at the zero angle: the measurements of total cross section differences Δσ L (np) and Δσ T (np), spin- correlation parameters A 00kk (np) and A 00nn (np) as well as unpolarized measurements of values σ tot (np), dσ/dt(np  pn). For the Direct Reconstruction of the Re parts of the Scattering Amplitudes we measure also the ratio R dp = dσ/dt(nd) / dσ/dt(np) for the charge exchange quasi-elastic and elastic processes at 0° using the D2 and H2 targets. It will allow one of some sign uncertainties to be eliminated.

9 H 2 targetsD 2 targets

10 Dean formula Using the impulse approximation the differential cross section of nd → p(nn) reaction can be expressed by the Flip and Non-Flip contributions of charge exchange np → pn process: N.W. Dean: Phys. Rev D 5 1661; Phys. Rev D 5 2832

11 Measurement of neutron-proton spin obsevables at 0° using highest energy polarized d, n probes --------------------------------------------------------------- L.N. Strunov et al.: Czechoslovak Journal of Physics, Vol. 55 (2005) Preliminary 2005 2005 V.L. Luboshitz remark The Dean formula have been obtained for small momentum transfer when the scattering angle θ closes to 0. And for the calculation the R dp ration we can use the amplitudes of the Charge Exchange only!---------------------------------------------------------------------------- V.V.Glagolev, V.L.Luboshitz, V.V.Luboshitz, N.M.Piskunov CHARGE-EXCHANGE BREAKUP OF THE DEUTRON WITH THE PRODUCTION OF TWO PROTONS AND SPIN STRUCTURE OF THE AMPLITUDE OF THE NUCLEON CHARGE TRANSFER REACTION wrong approach which used amplitudes of np-np(180)

12 Spin Singlet interaction S = 0 Initial and final neutrons have parallel spin projection Initial and final neutrons have antiparallel spin projection REPRESENTATION REPRESENTATION Elastic backward Charge Exchange Non-Flip Spin-Flip REPRESENTATION REPRESENTATION Elastic backward Charge Exchange Spin-Flip Non-Flip

13 Goldberger-Watson amplitudes representation

14 Directly unitary transition If scattering angle θ equal 0°, then:

15 If to use now the next labels: Then we obtain the formulas: V.L.Luboshitz, V.V.Luboshitz: in Proceedengs of the XIV International Seminar on Interaction of Neuterons with Nuclei, Dubna (2007) E3-2007-23, p.64-74.

16 If the amplitudes a and a CEX are identical then the Non-Flip equals to the SS amplitude 

17 R dp For calculation the R dp energy dependence the PSA solutions VZ40, FA91, SP07 from SAID DATA BASE was used said@gwdac.phys.gwu.edu said@lux2.phys.va.gwu.edu (R.A. Arnd, I.I. Strakovsky et al.) The values of the Charge Exchange amplitudes at the θ = 0° have been obtain from the np -Elastic backward amplitudes using presented formulas The experimental Delta Sigma points of R dp are the directly relation of yields of and process of nd→p(nn) and np→pn process

18 r nfl/fl The ratio r nfl/fl is defined as follows Teoretical values from PSA Experimental points

19 r nfl/fl

20 CONCLUSION Using Dean formula and the values of R dp ratio we define the ratio r nfl/fl and separate Flip & Non-Flip parts of np – pn Charge Exchange forward process Good agreement with PSA solution have been obtain due to the unitary transformation Consistency between the theory and experimental data show that the ratios R dp and r nfl/fl is a good observables and it will be used as an additional constraint for DRSA method


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