Dubna SPIN-09Delta-Sigma experimentt1 Delta-Sigma experiment. The results obtained and Δσ T (np) measurements planned using new high intensity polarized deuteron beam at the Nuclotron-M Veksler and Baldin Laboratory of High Energy Physics Joint Institute for Nuclear Research

Dubna SPIN-09Delta-Sigma experimentt2 Outline Introduction. Urgency of the data obtaining for np spin observables in the GeV region. Aim of the Delta-Sigma experiment. Determination of the Δσ L,T (np), A 00kk (np), A 00nn (np) and R dp observables and research program of experiment. Experimental set-up with instrumentation for transmission Δσ L,T (np) measurements and magnetic spectrometer for elastic np  pn charge exchange events detection. The results obtained in frame of Delta-Sigma experiment research program. Coming Δσ T (np) measurements at the Nuclotron-M.

Dubna SPIN-09Delta-Sigma experimentt3 “The theory of the nucleon-nucleon (NN) interaction in the range of about 1-10 GeV is one of the most pressing open questions of modern Nuclear / particle physics. Below that energy range, chiral effective field theory applies as well as meson theory. At very high energies (~ 100 GeV) perturbative QCD can be used. But it is the “intermediate” region of a few GeV where theory has big problems. Meaningful theoretical work cannot be done unless we have also data in that critical region. The data for np are very scarce, too few to even pin down a reasonable phenomenology. For our understanding of the fundamental NN interaction on a broad scale, it is vital to have data for np spin observables in the GeV region. These data will be useful for the entire international nuclear / particle physics Community ”. Ruprecht Machleidt Professor of Physics One of the authors of the Bonn NN potential.

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Dubna SPIN-09Delta-Sigma experimentt5 The aim of the project is to extend investigations of NN interaction over a new high energy region of free polarized neutron beams 1.2 – 3.7 GeV provided at present only at the JINR VBLHEP. The main task of these studies is determination for the first time the imaginary and real parts of all spin- dependent elastic np forward scattering amplitudes over this energy region. To reach this aim, a complete data set on energy dependencies of np spin-dependent observables have to be obtained for direct and simple reconstruction of these amplitudes.

Dubna SPIN-09Delta-Sigma experimentt6 At the forward (θ CM = 0) and backward (θ CM = π) angles five complex invariant amplitudes a, b, c, d, and e from the invariant amplitudes representation, which are the functions of the angle θ CM and energy E CM, satisfy the following equations: a(0) − b(0) = c(0) + d(0), e(0) = 0, (1) a(π) − b(π) = c(π) − d(π), e(π) = 0. (2) Therefore only three complex amplitudes are independent in these directions. The forward and backward scattering amplitudes are connected by the angular symmetry conditions. We assume that the I = 1 amplitudes are known. Consequently for the direct reconstruction of the np forward amplitudes, altogether, at least six independent np observables at either the forward or backward directions are needed.

Dubna SPIN-09Delta-Sigma experimentt7 The Delta-Sigma research program foresees the measurements of total cross section differences Δσ L,T (np) and spin correlation parameters A 00kk (np) and A 00nn (np) at θ CM = π for the longitudinal (L - along the incident nucleon momentum k) and transverse (T – along the perpendicular n to the k) beam and target polarization directions, respectively.

Dubna SPIN-09Delta-Sigma experimentt8 The Delta-Sigma experiment research program 1. Using longitudinally (L) and transverse (T) polarized neutron beams and polarized proton target to measure the energy dependencies of a) the total cross section differences Δσ L (np) and Δσ T (np) for parallel and antiparallel directions of beam and target polarizations, with energy steps of 100–200 MeV and expected statistical errors of 1 mb. The observables Δσ L (np) and Δσ T (np) are linearly related to the imaginary parts of the two spin-dependent forward scattering invariant amplitudes c and d via optical theorems and allow to extract these imaginary parts. b) the spin-correlation parameters A 00 kk (np) and A 00 nn (np) with expected statistical errors of 0.02 – 0.05 (simultaneously with and independently of the Δσ L,T (np) measurements). The A 00kk (np) and A 00nn (np) values will be obtained from a registration of yields of elastic charge exchange process np→ pn at 0º angle. They are related to the real parts of the amplitudes mentioned above and data to be obtained will be used to extract these real parts.

Dubna SPIN-09Delta-Sigma experimentt9 The Delta-Sigma experiment research program 2.Using high intensity unpolarised neutron beam and liquid hydrogen and deuterium targets to measure c) the ratio R dp = [dσ/dΩ(nd→pnn)] / [dσ/dΩ(np→pn)] for elastic charge exchange process np→ pn at 0º angle on deuterium and hydrogen targets with 5% statistical errors at the same energies as for i. 1. Experimental observable R dp is the ratio of a quasi-elastic nd scattering differential cross section to the free np elastic scattering one. The values of R dp can give one additional relation between spin-dependent NN-amplitudes and a set of such data allows to avoid one uncertainty of extraction of amplitudes real parts. The data set on energy behaviors of spin-dependent observables Δσ L,T (np), A 00kk (np), A 00nn (np) and R dp will be obtained for the first time over the energy range of neutron beam of 1.2–3.7 GeV. Besides the direct amplitude reconstruction, this data set will be used to extend the NN phase shift analysis to higher energies and to verify the dynamical model predictions.

Dubna SPIN-09Delta-Sigma experimentt10 Determination of Δσ L,T (np) Observables The general expression for the total cross section of a polarized nucleon beam trasmitted through a polarized proton target is (S.M.Bilenky and R.M.Ryndin, Phys.Lett. 6 (1963) 217, R.J.N. Phillips, Nucl.Phys. 43 (1963) 413): σ tot = σ 0tot + σ 1tot (P B P T ) + σ 2tot (P B k)(P T k), (3) where P B and P T are the beam and target polarizations, and k is the unit vector in the incident beam direction. The term σ 0tot is the spin-independent total cross section, and σ 1tot and σ 2tot are the spin-dependent contributions which connect with the observables Δσ T and Δσ L by the relations: – Δσ T = 2 σ 1tot = [σ tot (↑↑) – σ tot (↓↑)]/P B P T, (4) – Δσ L = 2 (σ 1tot + σ 2tot ) = [σ tot (→→) – σ tot (→←)]/P B P T. (5) From isotopic invariance of strong interaction, one can write the following expressions for total cross section differences at isosinglet and isotriplet states: Δσ L,T (np) = ½ Δσ L,T (I=0) + ½ Δσ L,T (I=1), (6) Δσ L,T (pp) = Δσ L,T (nn) = Δσ L,T (I=1), (7) Δσ L,T (I=0) = 2 Δσ L,T (np) – Δσ L,T (pp). (8) Using the last equation, one can obtain values of Δσ L,T (I=0) from known quantities of Δσ L,T (np) and Δσ L,T (pp), measured at the same energy.

Dubna SPIN-09Delta-Sigma experimentt11 Values of σ 0tot, Δσ T and Δσ L are connected with the imaginary parts of three invariant forward scattering amplitudes a + b, c and d via three optical theorems: σ 0tot = (2π/K) Im [a(0) + b(0)], (9) – Δσ T = (4π/K) Im [c(0) + d(0)], (10) – Δσ L = (4π/K) Im [c(0) – d(0)]. (11) From measured Δσ L,T (np) values one can unambiguously extract imaginary parts of invariant forward scattering amplitudes c and d using Eq. (10,11).

Dubna SPIN-09Delta-Sigma experimentt12 The A 00kk (np) and A 00nn (np) values are to be defined in the backward direction. These observables will be measured by registration of yields of elastic charge exchange process np  pn at θ Lab = 0. They could be measured simultaneously with the corresponding Δσ L,T (np) transmission experiments.

Dubna SPIN-09Delta-Sigma experimentt13 Measurements of the spin-correlation parameters A 00kk (np) and A 00nn (np) from np→pn process at 0º in Lab If the scattered particles are detected at 0º angle then only two non- vanishing spin-dependent quantities A 00nn (E,0º) and A 00kk (E,0º) can be measured from the np→pn scattering. C.Lechanoine-Leluc and F.Lehar. Rev. Mod. Phys. 65, 47 (1993). J. Ball, R.Binz, J.Bystricky et al. Eur.Phys.J. C 5, 57 (1998). These np-observables are connected with the invariant amplitudes by (the centre of mass system): dσ/dΩ (π) = ½ [|a| 2 + |b| 2 + |c| 2 + |d| 2 ], (12) dσ/dΩ A 00nn (π) = ½ [|a| 2 – |b| 2 – |c| 2 + |d| 2 ], (13) dσ/dΩ A 00kk (π) = Re a* d + Re b* c. (14) These equations can be transformed to: dσ/dΩ (1 + A 00kk ) = |b + c| 2 = A + (Re b + Re c) 2, (15) dσ/dΩ (1 – A 00kk – 2A 00nn ) = |b – c| 2 = B + (Re b – Re c) 2, (16) dσ/dΩ (1 – A 00kk + 2A 00nn ) = |b + c – 2d| 2 = = C + (Re b + Re c – 2Re d) 2, (17) where terms A, B, C contain the amplitudes imaginary parts only.

Dubna SPIN-09Delta-Sigma experimentt14 Using the known imaginary parts of the forward amplitudes transformed into the backward direction, the np differential cross section and the two spin correlation parameters A 00kk (np) and A 00nn (np) at θ CM = π are sufficient to obtain the real parts of all the three amplitudes from Eqs. (15) − (17).

Dubna SPIN-09Delta-Sigma experimentt15 But in contrast to the optical theorems at θ CM = 0, the scattering amplitudes in the backward direction are related to the np scattering observables by bilinear equations. Each of them may have, in principle, an independent ambiguity in the sign. The total ambiguity is then eight-fold at most and any independent experiment decreases it by a factor of two.

Dubna SPIN-09Delta-Sigma experimentt16 To reduce the total ambiguity in the scattering amplitude determination, the Delta-Sigma collaboration performed the measurements of the ratio R dp = dσ/dΩ (nd→p(nn)) / dσ/dΩ (np→pn). for the charge exchange processes on the deuterium and hydrogen targets.

Dubna SPIN-09Delta-Sigma experimentt17 Experimental observable R dp = dσ/dΩ(nd→p(nn )) / dσ/dΩ(np→pn) (18) is the ratio of a quasi-elastic nd scattering differential cross section to the free np elastic scattering one. At θ CM = π F.Lehar. Phys. Part. Nucl. 40, No. 6 (2009) R dp (π) = (2/3) · dσ/dΩ SD ( np) / dσ/dΩ(np), (19) R dp (π) = (2/3) · [0.25 · |a - b| · ( |c| 2 - |d| 2 )] / 0.5 · ( |a| 2 + |b| 2 + |c| 2 + |d| 2 ), (20) where dσ/dΩ SD ( np) is the “spin-dependent” part of the np→pn differential cross section. The values of R dp can give one additional relation between spin-dependent NN-amplitudes and a set of such data allows to avoid one uncertainty of extraction of amplitudes real parts. Energy dependence of the ratio R dp for elastic charge exchange process np→pn at 0º in Lab (or elastic np→np backward scattering in C.M.S.) has been measured using high intensity unpolarised neutron beam from the Nuclotron and the magnetic spectrometer of the Delta-Sigma set-up with liquid hydrogen and deuterium targets.

Dubna SPIN-09Delta-Sigma experimentt18 Accelerators and tools  The Synchrophasotron, Nuclotron and Nuclotron-M VBLHEP, JINR. Relativistic 1 – 5 GeV polarized neutron beams with average polarization value of 0.53, orientation of polarization L or T and reversion of polarization direction from cycle to cycle; unpolarized neutron beam with high intensity (4x10 6 n/cycle at T n = 2 GeV).  Large (140 cm 3 ) polarized proton target with polarization value of 0.7–0.8.  Cryogenic hydrogen H 2 and deuterium D 2 targets (L = 30 cm).  “ Delta-Sigma” set-up with: monitor and transmission neutron detectors; magnetic spectrometer with proportional chambers; detectors for target surrounding; time-of-flight system; adequate data acquisition system.

Dubna SPIN-09Delta-Sigma experimentt19 DELTA-SIGMA Setup at the Polarized Neutron Beams of the JINR VBLHE VP 1 – beam line of polarized deuterons; 1V – beam line of polarized neutrons; BT – beryllium neutron production target; IC – ionization chamber; PIC 1-3, 9-16 – multiwire proportional/ionization chambers; CM – sweeping magnet; C1-C4 – set of neutron beam collimators; SRM – neutron spin rotating magnet; PPT – polarized proton target; NP – neutron profilometer

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Dubna SPIN-09Delta-Sigma experimentt22 Measurements of the − Δσ L (np) energy dependence were carried out at ten different values of the polarized neutron beam energy from 1.2 to 3.7 GeV. The L-polarized neutron beam at the Synchrophasotron facility of the JINR VBLHE and the Dubna L-polarized proton target were used.

Dubna SPIN-09Delta-Sigma experimentt23 Energy Dependence of the –Δσ L (np) Observable Obtained with Free Neutron Polarized Beams

Dubna SPIN-09Delta-Sigma experimentt24 Energy Dependence of the –Δσ L (I=0)

Dubna SPIN-09Delta-Sigma experimentt25 Measurements of the −Δσ L (np) energy dependence were in the main completed. Results were published in: References on –Δσ L (np) results 1. B.P.Adiasevich, V.G.Antonenko, S.A.Averichev, L.S.Azhgirey et al. Zeitschrift fur Physik C71 (1996) V.I.Sharov, S.A.Zaporozhets, B.P.Adiasevich, V.G.Antonenko et al. JINR Rapid Communications 3[77]-96 (1996) V.I.Sharov, S.A.Zaporozhets, B.P.Adiasevich, N.G.Anischenko et al. JINR Rapid Communications 4[96]-99 (1999) V.I.Sharov, S.A.Zaporozhets, B.P.Adiasevich, N.G.Anischenko et al. European Physical Journal C13 (2000) V.I.Sharov, N.G.Anischenko, V.G.Antonenko, S.A.Averichev et al. European Physical Journal C37 (2004) V.I.Sharov, N.G.Anischenko, V.G.Antonenko, S.A.Averichev et al. Yadernaya Fizika v.68, №11 (2005) Physics of Atomic Nuclei v.68, №11 (2005)

Dubna SPIN-09Delta-Sigma experimentt26 The magnetic spectrometer consist of the analyzing dipole SP94, two sets of multiwire proportional chambers PCs: Gx, Gy, 1x, 2x before and PCs: 3x, 3y, 4x, 4y after SP94 for momentum analyzis of detected secondaries; Time-of flight system S1, TOF1,2 for particle identification; Liquid H 2 / D 2 or solid CH2 / CD2 targets inserted in the neutron beam line instead of the PPT and surrounded by a device DTS for detecting charged recoils and gammas; Trigger counters A, S1, ST1,2,3.

Dubna SPIN-09Delta-Sigma experimentt27 Multiwire proportional chambers Wires spacing is 2 mm for all PCs. PCs name Upstream the analysing magnet: Gx, Gy 64 wires ( 128 mm ). 1x, 2x 96 wires ( 192 mm ). Downstream the analysing magnet: 3x, 4x 192 wires ( 384 mm ). 3y, 4y 144 wires ( 288 mm ). Total: 848 wires

Dubna SPIN-09Delta-Sigma experimentt28 PCs efficiencies at 1.4 GeV. H2 target. Zero All One Two Cl2 Mn2 On - line 1 1x x x y gy gx x Total: Off – line EffPC dEffPC ( One + Cl2 ) 1 1x x During the data treatment, the 3 3x information from PC 1x “or” PC 2x 4 3y and PC 3x “or”/”and” PC 4x 5 gy was used. 6 gx x Total: 0.887

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Dubna SPIN-09Delta-Sigma experimentt33 ЯДЕРНАЯ ФИЗИКА, 2009, том 72, №6, с. 1051–1064 ЭЛЕМЕНТАРНЫЕ ЧАСТИЦЫ И ПОЛЯ THE RATIO Rdp OF THE QUASI-ELASTIC nd→p(nn) TO THE ELASTIC np→pn CHARGE-EXCHANGE-PROCESS YIELDS AT THE PROTON EMITTING ANGLE θp,lab = 0◦ OVER 0.55–2.0-GeV NEUTRON BEAM ENERGY REGION. EXPERIMENTAL RESULTS V. I. Sharov1)*, A. A. Morozov1), R.A.Shindin1), V.G.Antonenko2), S. B. Borzakov3), Yu. T. Borzunov1), E. V. Chernykh1), V. F. Chumakov1), S.A.Dolgii1), M. Finger4), 5), M.Finger, Jr.4), L. B. Golovanov1), D. K. Guriev1), A. Janata4), A. D. Kirillov1), A. D. Kovalenko1), V.A.Krasnov1), N. A. Kuzmin6), A. K. Kurilkin1), P. K. Kurilkin1), A.N.Livanov1), V.M.Lutsenko6), P.K.Maniakov1), E. A. Matyushevsky1), G. P. Nikolaevsky1), A. A. Nomofilov1), Tz. Panteleev3), 7), S. M. Piyadin1), I. L. Pisarev4), Yu. P. Polunin 2), A. N. Prokofiev8), V.Yu.Prytkov1), P.A.Rukoyatkin1), M. Slunecˇ ka4), 5), V.Slunecˇ kova. 4), A.Yu.Starikov1), L.N.Strunov1), T. A. Vasiliev1), E. I. Vorobiev1), I.P.Yudin6), I.V.Zaitsev1), A. A. Zhdanov8), V.N.Zhmyrov4) Received May 20, 2008; in final form, December 29, 2008 Physics of Atomic Nuclei, 2009, Vol. 72, No. 6, pp. 1007–1020. ELEMENTARY PARTICLES AND FIELDS Experiment

Dubna SPIN-09Delta-Sigma experimentt34 Physics of Atomic Nuclei, 2009, Vol. 72, No. 6, pp. 1007–1020. ELEMENTARY PARTICLES AND FIELDS Experiment The Ratio Rdp of the Quasielastic nd→p(nn) to the Elastic np→pn Charge-Exchange-Process Yields at the Proton Emitting Angle θp,lab = 0◦ over 0.55–2.0 GeV Neutron Beam Energy Region. Experimental Results* V. I. Sharov1) ∗∗, A. A. Morozov1), R.A.Shindin1), V.G.Antonenko2), S. B. Borzakov3), Yu. T. Borzunov1), E.V.Chernykh1), V. F. Chumakov1), S. A. Dolgii1), M.Finger4),5), M. Finger, Jr.4), L. B. Golovanov1), D. K. Guriev1), A. Janata4), A. D. Kirillov1), A.D. Kovalenko1), V. A. Krasnov1), N. A. Kuzmin6), A. K. Kurilkin1), P. K. Kurilkin1), A. N. Livanov1), V.M.Lutsenko6), P.K.Maniakov1), E. A. Matyushevsky1), G. P. Nikolaevsky1), A. A. Nomofilov1), Tz. Panteleev3),7), S. M. Piyadin1), I. L. Pisarev4), Yu.P.Polunin†2), A.N.Prokofiev8), V.Yu.Prytkov1), P.A.Rukoyatkin1), M. Slunecˇ ka4),5), V.Slunecˇ kova. 4), A.Yu.Starikov1), L.N.Strunov1), T. A. Vasiliev1), E. I. Vorobiev1), I.P.Yudin6), I.V.Zaitsev1), A.A.Zhdanov8), and V. N. Zhmyrov4) Received May 20, 2008; in final form, December 29, 2008

Dubna SPIN-09Delta-Sigma experimentt35 ЯДЕРНАЯ ФИЗИКА, 2009, том 72,№6, с. 1065–1069 ЭЛЕМЕНТАРНЫЕ ЧАСТИЦЫ И ПОЛЯ THE RATIO Rdp OF THE QUASI-ELASTIC nd→p(nn) TO THE ELASTIC np→pn CHARGE-EXCHANGE-PROCESS YIELDS AT THE PROTON EMITTING ANGLE θp,lab = 0◦ OVER 0.55–2.0-GeV NEUTRON-BEAM ENERGY REGION. COMPARISON OF THE RESULTS WITH THE MODEL-DEPENDENT CALCULATIONS V. I. Sharov*, A. A. Morozov, R. A. Shindin, E. V. Chernykh, A. A. Nomofilov, L. N. Strunov Joint Institute for Nuclear Research, Dubna, Russia Received May 20, 2008; in final form, October 4, 2008 Physics of Atomic Nuclei, 2009, Vol. 72, No. 6, pp. 1021–1025. ELEMENTARY PARTICLES AND FIELDS Experiment

Dubna SPIN-09Delta-Sigma experimentt36 Physics of Atomic Nuclei, 2009, Vol. 72, No. 6, pp. 1021–1025. ELEMENTARY PARTICLES AND FIELDS Experiment The Ratio Rdp of the Quasielastic nd→p(nn) to the Elastic np→pn Charge-Exchange-Process Yields at the Proton Emitting Angle θp,lab = 0 over 0.55–2.0 GeV Neutron-Beam Energy Region. Comparison of the Results with the Model- Dependent Calculations* V. I. Sharov**, A. A. Morozov, R. A. Shindin, E. V. Chernykh, A. A. Nomofilov, and L. N. Strunov Joint Institute for Nuclear Research, Dubna, Russia Received May 20, 2008; in final form, October 4, 2008

Dubna SPIN-09Delta-Sigma experimentt37 The project status R E P O R T ON SCIENTIFIC PROJECT AND PROPOSAL FOR PROLONGATION OF THESE INVESTIGATIONS FOR 2010–2012 UNDER NEW PROJECT Delta-Sigma-T (proposal)

Dubna SPIN-09Delta-Sigma experimentt38 REASONS FOR THE PROJECT PROLONGATION The proposed experimental program was not fully carried out in time ( ) mainly due to the financial and organization reasons. Some of them are: Continuation of polarization measurements was impossible because the Synchrophasotron, provided the unique highest energy polarized deuterons, was taken out of operation. Measurements of the Δσ L,T (np), A 00kk (np) and A 00nn (np) energy dependences using L and T orientations of beam and target polarizations will be possible in the near future when the new high intensity source of polarized deuterons CIPIOS will be put in operation at the Nuclotron An absence of additional PPT equipment to produce transverse polarized protons at the PPT. This equipment is in preparation now but the works in this field are hindered by the absence of payments from the JINR budget. An absence of sufficient funding for activity under the project. An estimation of expenditures for the project approved in 2003 foreseen k$ expenses every year (35k$ in total) for some additional necessary needed equipment and materials. However, the funding was less than required (near 10k$ in total).

Dubna SPIN-09Delta-Sigma experimentt39 THE COMING RESEARCH PROGRAM The coming research program under the project on 2010–2012 is following: Using adequate T-polarized neutron beam and T- polarized proton target to perform –the measurements of the Δσ T (np) at the same energy points (1.2 – 3.7 GeV) as for Δσ L (np) with energy steps of 100–200 MeV and expected statistical errors ≤ 0.5 mb; –the measurements of the energy dependencies of spin- correlation parameter A 00nn (np) at the same energy points as for Δσ T (np) with expected statistical errors 0.02–0.05. These measurements will be performed simultaneously with and independently of the Δσ T (np) ones.

Dubna SPIN-09Delta-Sigma experimentt40 Measurements of the Δσ T (np) and A 00nn (np) energy dependences using T orientations of beam and target polarizations will be possible in the near future when the new high intensity source of polarized deuterons SPD will be put in operation at the Nuclotron-M and when the T mode of target polarization will be ready.

Dubna SPIN-09Delta-Sigma experimentt41 A.Sidorin talk, April 16, Nuclotron_M status and nearest plans. Development and creation of a high-intensity polarized deuteron source (V.Fimushkin) We continue collaboration works with INR (Troitsk) on the development of the new high-intensity polarized deuteron source, and signed an addendum for work prolongation in We plan to complete TDR documentation in this year and start construction of some elements at INR. Simulation, modeling and design of different elements of the future source is in active phase at LHEP. Experimental hall for the future test bench with that source is prepared at LHEP building 203A, preparation electrical and water-cooling works were performed. It is purchased part of necessary vacuum equipment (turbomolecular pumps) for the SPD realization in 2009 – delivery in August SPD putting into operation: the end of 2010.

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Dubna SPIN-09Delta-Sigma experimentt45 If intensity of the polarized deuteron beam will be 2х10 10 d/cycle then: at the neutron beam energy Tn = 1.2 GeV during 8 hours will be accumulated a statistics provides the −∆σ T (np) statistical error of ≈ 0.1 mb. The A 00nn (np), measured simultaneously with and independently of the Δσ L,T (np) measurements, will has less then 0.05 statistical error.

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Dubna SPIN-09Delta-Sigma experimentt47 FURTHER DESIRED MEASUREMENTS Using suitable L-polarized neutron beam and L-polarized proton target to perform - the more precise and detailed measurements of the Δσ L (np) near T n =1.8 GeV at 2–3 energy points with energy steps of 100 MeV and expected statistical errors less than 0.5 mb; - the measurements of the energy dependencies of spin- correlation parameters A 00kk (np) at the same energy points as for Δσ L (np) with expected statistical errors 0.02–0.05. These measurements can be performed independently of the Δσ L (np) ones. Using a high intensity unpolarized deuteron beam for preparing free neutron beam and liquid hydrogen and deuterium targets to continue the measurements of ratio Rdp=dσ/dΩ(nd) / dσ/dΩ(np) for elastic charge- exchange process np→pn at 0° angle with 5% statistical errors at the energies more then 2.0 GeV.

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Dubna SPIN-09Delta-Sigma experimentt50 The investigations under the project program were in part supported by the International Science Foundation and Russian Government, Grant N JHW 100, the Russian Foundation for Basic Research, Grants N , N , N

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Dubna SPIN-09Delta-Sigma experimentt54 Participants of the "DELTA-SIGMA" experiment S.A.Averichev, L.S.Azhgirey, N.G.Anischenko, V.D.Bartenev, A.Bazhanov, N.A.Blinov, N.S.Borisov, S.B.Borzakov, Yu.T.Borzunov, T.N.Borzunova, E.I.Bunyatova, V.F.Burinov, Yu.P.Bushuev, L.P.Chernenko, E.V.Chernykh, V.F.Chumakov, S.A.Dolgii, A.N.Fedorov, V.V.Fimushkin, M.Finger 1, M.Finger,Jr., L.B.Golovanov, D.K.Guriev, A.Janata 2, A.D.Kirillov, V.G.Kolomiets, E.V.Komogorov, A.D.Kovalenko, I.G.Konskii, N.I.Kochelev, V.A.Krasnov, E.S.Kuzmin, N.A.Kuzmin, V.P.Ladygin, A.B.Lazarev, A.N.Livanov, P.K.Maniakov, E.A.Matyushevsky, A.A.Morozov, A.B.Neganov, G.P.Nikolaevsky, A.A.Nomofilov, Tz.Panteleev 3, Yu.K.Pilipenko, I.L.Pisarev, Yu.A.Plis, R.V.Polyakova, V.Yu.Prytkov, P.A.Rukoyatkin, V.I.Sharov, T.V.Shavrina, S.N.Shilov, R.A.Shindin, Yu.A.Shishov, V.B.Shutov, O.N.Schevelev, M.Slunechka, V.Slunechkova, A.Yu.Starikov, L.N.Strunov, Yu.A.Usov, T.A.Vasiliev, V.I.Volkov, E.I.Vorobiev, I.P.Yudin, I.V.Zaitsev, V.N.Zhmyrov, Joint Institute for Nuclear Research, Dubna 1 Charles University, Praha, Czech Republic 2 Institute for Nuclear Research, Rez, Czech Republic 3 Institute for Nuclear Research and Nuclear Energy, BAS, Sofia, Bulgaria V.G.Baryshevsky, K.G.Batrakov, T.I.Klimkovich, S.L.Cherkas RNNP,Belorussian State University, Belorussia A.I.Kovalev, A.N.Prokofiev, V.A.Schedrov, A.A.Zhdanov Peterburg Institute of Nuclear Physics, Gatchina G.M.Gurevich Institute for Nuclear Research, RAS, Moscow V.G.Antonenko, Yu.P.Polunin Russian Scientific Center "Kurchatov Institute", Moscow F.Lehar. A. de Lesquen DAPNIA, Saclay, France A.A.Belyaev, A.A.Lukhanin Kharkov Institute of Physics and Technology, Kharkov, Ukraine

Dubna SPIN-09Delta-Sigma experimentt55 Nucleon-Nucleon Formalism Throughout the project and results publications we used the NN formalism and notations for elastic nucleon-nucleon scattering observables from Bystricky J., Lehar F., Winternitz P. J. Phys. (Paris) v.39. p. 1. Assuming parity conservation, time-reversal invariance, the Pauli principle, and isospin invariance, the nucleon-nucleon scattering matrix can be written in term of only five invariant amplitudes M(k', k) = ½ [(a+b)+(a-b)(σ 1,n)(σ 2,n)+(c+d)(σ 1,m)(σ 2,m)+(c-d)(σ 1,l)(σ 2,l)+e(σ 1 +σ 2,n)], (1) where σ 1 and σ 2 are the Pauli 2x2 matrices acting on the first and second nucleon wave functions, and k and k' are unit vectors in the direction of the incident and scattered particles, respectively. The invariant amplitudes a, b, c, d and e are complex functions of two variables, e. g., the center of mass (c. m.) energy k and scattering angle θ. In the forward direction at θ=0, total angular momentum conservation implies that e=0 and a-b=c+d. Similarly at 180º one obtains e=0 and a-b=c-d. The center of mass basis vectors are given by l = (k'+k)/(|k'+k|), m = (k'-k)/(|k'-k|), n = (k' x k)/(|k' x k|). (2)

Dubna SPIN-09Delta-Sigma experimentt56 For the pp, nn, and np interactions, the scattering matrix can be written in term of two matrices M 0 and M 1 having the same form as Eq. (1) M(k',k) = ¼ M 0 [1-(τ 1, τ 2 )] + ¼ M 1 [3+(τ 1, τ 2 )], (3) where τ 1 and τ 2 are isosinglet and isotriplet scattering matrices. Ignoring electromagnetic interaction, one can write M(pp→pp) = M(nn→nn) = M 1, M(np→np) = M(pn→pn) = ½ (M 1 +M 0 ), (4) M(np→pn) = M(pn→np) = ½ (M 1 -M 0 ). This formalism uses a four-subscript notation X srbt for experimental quantities. Subscripts s, r, b, and t refer to the polarization components of the scattered, recoil, beam, and target particles, respectively. For any c. m. observable X pqik, the following expression holds dσ/dΩ X pqik = ¼ Tr ( σ 1p σ 2q M σ 1i σ 2k M + ), (5) where dσ/dΩ = I 0000 = ¼ Tr ( M M + ), (6) is the unpolarized differential cross section.

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Dubna SPIN-09Delta-Sigma experimentt60 Neutron Beam Parameters The beam of free quasi-monochromatic neutrons is obtained by break-up of deuterons at 0º in the Beryllium target BT (20 cm×8×8 cm 2 ). Neutron beam is formed by a set of collimators C1–C4. The deuteron beam momentum P d is known with accuracy of ~1 %. The neutron beam has the momentum P n = P d /2 with a gaussian momentum spread of FWHM ~ 5 %. Intensity of prepared neutron beam at T n = 2.0 GeV was ~4∙10 6 n/cycle. For the Δσ L measurements, the neutron spins are rotated from vertical direction to the direction of beam momentum by spin rotating magnet SRM.

Dubna SPIN-09Delta-Sigma experimentt61 Experimental set-up for the Δσ L,T (np) measurements. Layout of the detectors for the neutron transmission measurement. C4 − last neutron beam collimator, 25 mm in diameter; M1, M2 − monitor neutron detector modules; PPT − polarized proton target; T1, T2, T3 − neutron transmission detector modules; CH 2 − converters; NP − neutron beam profile monitor; A − anticoincidence scintillation counters; S1 − S4 − coincidence scintillation counters; PC − multiwire proportional chambers.

Dubna SPIN-09Delta-Sigma experimentt62 Time dependence of neutron beam polarization P B during the 2001 data taking run.

Dubna SPIN-09Delta-Sigma experimentt63 Characteristic of the polarized proton target in 2001 data taking run

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Dubna SPIN-09Delta-Sigma experimentt68 Measurements of the Δσ L,T (np) and A 00kk (np) and A 00nn (np) energy dependences using L and T orientations of beam and target polarizations will be possible in the near future when the new high intensity source of polarized deuterons (CIPIOS) will be put in operation at the Nuclotron and when the T mode of target polarization will be ready. During the last period, in frame of the project experimental program, the studies of elastic np→pn charge exchange process were carried out using high intensity unpolarized neutron beams and cryogenic H 2 and D 2 targets (l=34 cm). The results of these measurements will be presented below.

Dubna SPIN-09Delta-Sigma experimentt69 Some characteristics of the spectrometer. Accuracies: θ x : bin 1.97 mrad, instrum. error 0.83 mrad for PCs Gx-1x, bin 1.79 mrad, instrum. error 0.76 mrad for PCs Gx-2x. θ y : bin 0.61 mrad, instrum. error 0.26 mrad for PCs Gy-3y. σP/P: measured at the extracted deuteron beam 1.40 % using PCs Gx, 1x “or” 2x,(3x “and” 4x) or (3x “or” 4x), 1.37 % using PCs Gx, 2x, 3x and 4x only.

Dubna SPIN-09Delta-Sigma experimentt70 Detected events distribution in the θ vs φ plane

Dubna SPIN-09Delta-Sigma experimentt71 The momentum spectra of charged secondaries for H 2 and D 2 liquid targets at the neutron beam energies of 1.0 and 1.2 GeV.

Dubna SPIN-09Delta-Sigma experimentt72 Separation of the p and d particles in the TOF vs Momentum plane

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Dubna SPIN-09Delta-Sigma experimentt74 Information from the detectors for target surrounding DTS allows to suppress the contributions from other (inelastic) np-reaction channels. The momentum spectra of charged secondaries at the neutron beam energy of 1.8 GeV. a- with liquid hydrogen target b- with liquid deuterium target

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Dubna SPIN-09Delta-Sigma experimentt76 Systematical errors. Estimations for data at Tn = 1.4 GeV. Sources of systematic error Absolute values of the Rdp error 1. Total PC efficiency Trigger PC efficiency Efficiency of the DTS Efficiency of TOF d-admixtures determination Error in shift determination of the H2 and D2 elastic peak center positions Number of H/D nuclei in the targets Total:

Dubna SPIN-09Delta-Sigma experimentt77 ACCELERATOR RUN TIME REQUEST

Dubna SPIN-09Delta-Sigma experimentt78 COSTS CALCULATION

Dubna SPIN-09Delta-Sigma experimentt79 Scientific publications (last 3 years) 1. "MEASUREMENT OF Δσ L (np) AT 1.39, 1.69, 1.89 AND 1.99 GeV." European Physical Journal C37 (2004) соавтора. 2. "MEASUREMENT OF THE TOTAL CROSS-SECTION DIFFERENCE Δσ L (np) AT 1.39, 1.69, 1.89 AND 1.99 GeV." Preprint JINR E соавтора. 3. "Measurements of Energy Behaviours of Spin Dependent Neutron-Proton Observables over a GeV Region." 75 соавторов. Czech. J. Phys. 54, p.p. B , "Measurements of Energy Behaviours of Spin Dependent Neutron-Proton Observables over a GeV Region." 75 соавторов. In: Proceedings of the XVI International Seminar on High Energy Physics Problems. Relativistic Nuclear Physics and Quantum Chromodynamics. Dubna, June , Ed. by A.N. Sissakian, V.V. Burov, A.I. Malakhov. E1, , Vol. II, p.p Dubna, "Measurements of Energy Behaviours of Spin Dependent Neutron-Proton Observables over a GeV Region." 75 соавторов. In: Proceedings of the X Workshop on High Energy Spin Physics (NATO ARW DUBNA SPIN-03), Dubna, September 16-20, Ed. by A.V. Efremov, O.V. Teryaev. E1, , p.p Dubna, 2004.

Dubna SPIN-09Delta-Sigma experimentt80 6. "MEASUREMENTS OF ENERGY BEHAVIOURS OF SPIN-DEPENDENT np – OBSERVABLES OVER GEV REGION." 75 соавторов. In: Book of Abstracts of the XVII International Baldin Seminar on High Energy Physics Problems. Relativistic Nuclear Physics and Quantum Chromodynamics. Dubna, September 27- October 2, E1, , p.p Dubna, "MEASUREMENTS OF ENERGY BEHAVIOURS OF SPIN-DEPENDENT np – OBSERVABLES OVER GEV REGION." 75 соавторов. In: Proceedings of of the XVII International Baldin Seminar on High Energy Physics Problems. Relativistic Nuclear Physics and Quantum Chromodynamics. Dubna, September 27- October 2, E1, , p.p Dubna, "Measurements of the Total-Cross-Section Difference ΔσL(np) at 1.39, 1.69, 1.89, and 1.99 GeV." 73 соавтора. Ядерная физика. т. 68, № 11, 2005, сс. 1858– соавтора. 9. "Measurements of the Total-Cross-Section Difference ΔσL(np) at 1.39, 1.69, 1.89, and 1.99 GeV." 73 соавтора. Physics of Atomic Nuclei, Vol. 68, No. 11, 2005, pp. 1796–1811. (From Ядерная физика. т. 68, № 11, 2005, сс. 1858–1873.) 10. "Measurements of energy behaviours of spin-dependent np - observables over GeV region. Dubna "Delta-Sigma" experiment." 75 соавторов. Czech. J. Phys. 55 (2005) A289-A305.

Dubna SPIN-09Delta-Sigma experimentt "First measurement of the cross-section ratio R dp (0) in charge-exchange (np) reaction on H 2 /D 2 at 0o and Tn = 1 GeV. Dubna "Delta-Sigma" experiment." 38 соавторов. Czech. J. Phys. 55 (2005) A 307-A "Veto-system in measurement of the elastic (n,p) charge-exchange using H2/D2 – target at Tn = 1 GeV. Dubna "Delta-Sigma" experiment." 10 соавторов. Czech. J. Phys. 55 (2005) A399-A "MEASUREMENTS OF ENERGY BEHAVIOURS OF SPIN-DEPENDENT np – OBSERVABLES OVER GEV REGION." 75 соавторов. In: Proceedings of the XI Advanced Research Workshop on High Energy Spin Physics. (DUBNA-SPIN-05), Dubna, September 27 - October 1, Ed. by A.V. Efremov and S.V. Goloskokov, Dubna p.p "Measurements of neutron-proton spin observables at 0o using highest energy polarized d, n probes." 45 соавторов. Czech. J. Phys. 56 (2006) C343-C "Measurements of energy behaviours of spin-dependent np - observables over 1.2 – 3.7 GeV region. Dubna "Delta-Sigma" experiment." 72 соавтора. Czech. J. Phys. 56 (2006) C359-C "New measurement of the cross-section ratio Rdp(0) in charge-exchange (np) reaction on H2/D2 at 0o and Tn = 1; 1.2 GeV. Dubna "Delta-Sigma“ experiment." 38 соавторов. Czech. J. Phys. 56 (2006) C369-C "Measurements of neutron-proton spin observables at 0° using highest energy polarized d, n probes. Dubna "Delta-Sigma" experiment." 45 соавторов. Czech. J. Phys. 56 (2006) C343-C357.

Dubna SPIN-09Delta-Sigma experimentt82 Вторая премия ОИЯИ за 2003 год в области научно-методических исследований "Создание детектирующего комплекса установки "ДЕЛЬТА-СИГМА" для одновременных измерений под 0° на пучке монохроматических L/T- поляризованных нейтронов ЛВЭ ОИЯИ - полного комплекта np-наблюдаемых для прямого определения всех амплитуд нуклон-нуклонного рассеяния вперед, впервые при высоких энергиях". Авторы: Л.Н. Струнов, В.И. Шаров, А.А. Номофилов, А.А. Морозов, Е.В. Черных, Р.А. Шиндин, А.Н. Ливанов, В.Ю. Прытков, Н.А. Кузьмин, И.В. Зайцев.