Short-range correlations studies in collisions of polarized nuclei at Nuclotron-M

. The status and prospects of 2-nueleon and 3-nucleon short range correlations (SRCs) studies at Nuclotron-M (JINR) are presented. This program is focused on the investigations of the spin part of SRCs with polarized deuteron beam from new high intensity polarized deuterons ion source which is under development at JINR. The wide experimental program on the systematic studies of the polarization effects in dp- elastic scattering, dp- nonmesonic breakup, dd -h>3Hera(3H/>) and af3He -h> />4He reactions sensitive to SRCs using both internal and extracted beam at Nuclotron-M is presented.


Introduction
Short range correlations (SRCs) o f nucleons in nuclei is the subject o f intensive theoretical and experimental works during last years. Since SRCs have densities comparable to the density in the center o f a nucleon which is about p ~ 5p0 (po ~ 0-17 fm -3), they can be considered as the drops o f cold dense nuclear m atter [1]. These studies ex plore a new part o f the phase diagram and very essential to understand the evolution o f neutron stars.
The results obtained at BNL [2], SLAC [3] and JLAB [4,5] clearly demonstrate that: (i) more than 90% all nu cleons w ith momenta k > 300 MeV/c belong to 2N SRC; (ii) probability for a given proton w ith momenta 300 < k < 600 M eV/c to belong to p n correlation is ~18 times larger than for p p correlations; (iii) probability for a nucleon to have momentum > 300 M eV/c in medium nuclei is ~25%; (iv) 3N SRC are present in nuclei w ith a significant prob ability [6]. However, still many open questions persist and a e-m ail: v l a d y g i n @ j i n r . r u further investigations are required both from the experi mental and theoretical sides. For instance, the experimen tal data on the spin structure o f 2N (1=1) and 3N SRC are almost absent.
The main tools to study SRCs at hadronic facilities can be deuteron structure investigations at large internal m o menta allowing to explore 2N SRC with 1 = 0; 3He struc ture to understand the role o f 2N SRC with 1 = 1 and 3N SRC; nuclei breakup A (p ,p p )X , A (p ,p n )X , A (p ,p p p )X etc. with the detection o f few nucleons in the final state. The greate importance is the study o f the spin effects in these reactions because the data on the SRCs spin struc ture are scarce. Nuclotron-M and NICA will allow to in vestigate the spin effects for multi-nucleon correlations in a wide energy range.
The model o f 2N and 3N correlations at low and mod erate energies (below pion threshold production) can be built from the boson-nucleon picture o f strong interaction. During last several years a new generation o f nucleonnucleon potentials are built (Nijmegen, CD-Bonn, AV-18 etc.). These potentials reproduced the NN scattering data up to 350 M eV w ith very good accuracy. B ut these po tentials cannot reproduce triton binding energy (under binding is 0.8 M eV for CD-Bonn), deuteron-proton elas tic scattering and breakup data. Incorporation of three nu cleon forces (3NF), when the interaction depends on the quantum numbers o f the all three nucleons, allows to re produce triton binding energy and unpolarized deuteronproton elastic scattering and breakup data (see [7] and ref erences therein). The contribution o f 3NF is found to be up to 30% in the vicinity o f so called ''cross section min imum" (Sagara discrepancy) for deuteron-proton elastic scattering at intermediate energies [8,9]. However, the use o f different 3NF models in Faddeev calculations can not reproduce polarization data intensively accumulated dur ing last decade at different facilities [8]- [14].
O n the other hand, p d -elastic scattering cross sec tion data obtained already at 250 M eV [11] cannot be reproduced by the Faddeev calculations w ith the inclu sion o f m odem 3NF. The authors stated that the reason of this discrepancy can be neglecting by new type o f shortrange 3NF. These forces can be built w ithin approaches be yond one-boson-exchange. For instance, in the dressed bag model [15] 3NF comes from the interaction betw een inter mediate six-quark state dressed by cr-field and the third nu cleon. The description o f 2N and 3N correlations at the en ergies higher than several hundreds M eV/nucleon should be obtained within QCD [1].
The main goal o f the D S S -project at Nuclotron-M is the systematic studies o f the polarized deuteron-induced reactions at Nuclotron-M. The program includes two main directions.
-The measurements o f the cross section, vector A y and tensor. I,and A xx analyzing powers in dp-elastic scat tering at large angles in cms in the energy range 0.3 -2.0 GeV [16] and in dp-non-mesonic breakup at the energies below 500 M eV for different kinematic con figurations o f two final protons [17] at Internal Target Station (ITS) [18] at Nuclotron-M. -The measurements o f the cross section, tensor analyz ing power 7:2u and spin correlation parameter ( in the d3He -» /?(0°)4Hc reaction [19]- [21] at the ener gies betw een 1000 and 2000 M eV using polarized 3He target [22] and extracted polarized deuteron beam from new polarized ion source [23] at Nuclotron-M.
For these studies the development o f the efficient polarimetry for deuteron and nucleon beams at intermediate and high energies at Nuclotron-M is necessary [ 16,24,25].

Measurements at Internal Target Station
The ITS setup is well suited for study o f energy depen dence o f polarization observables for the deuteron-proton elastic scattering and deuteron breakup reaction with the detection o f two protons at large scattering angles [16].
For these purposes the CH2-target o f 10 mkm thick is used for the measurements. The yield from carbon content o f the CH2-target is estimated in separate measurements using carbon wire. The monitoring of the intensity is done from the detection o f p p -quasielastic scattering at 90° in cms by the scintillation counters placed in the horizontal plane. The detection o f the dp-elastic events is done by the coincidence measurements o f the proton and deuteron. The detectors are placed in the horizontal plane only for the cross section measurements and in the both horizon tal and vertical planes for the analyzing powers measure ments. The selection o f the dp-elastic events is done by the correlation o f the energy losses in plastic scintillators for deuteron and proton and their time-of-flight difference. The interaction point for each event is reconstructed by the target position monitor [26].
The measurements o f the deuteron analyzing powers in dp-elastic scattering have been performed at ITS us ing polarized beam from polarized ion source POLARIS [27] at the energies 880 and 2000 M eV [24,25]. The use o f large amount of the scintillation counters allowed cover wide angular range. The measurement o f the beam polar ization has been performed at 270 M eV where the data on the tensor and vector analyzing powers based on the abso lute calibration o f the beam polarization exist [28].

^-e la s tic scattering at 880 MeV
The results on the angular dependence o f the vector. I,, and tensor. I,and A xx obtained at 880 M eV are shown in Fig. 1 by the solid symbols. The solid, dashed and dash-dotted lines are the results o f the Faddeev calculations [29] using CD-Bonn nucleon-nucleon potential [30], o f the relativistic multiple scattering calculations [31] using CD-Bonn [30] deuteron wave function (DWF), and the optical poten tial calculation [32] w ith the dibaryon DWF [15], respec tively. One can see that Faddeev and relativistic multiple scattering models give good description o f the data except for A xx.  1. Vector A v, tensor A m and A IX analyzing pow ers in dpelastic scattering at 880 M eV [24,25]. The lines are the predic tions o f different m odels [29,31,32] (explained in the text).
On the other hand, Faddeev calculations [29] fail to reproduce the cross section at the angles larger than 90°, while relativistic multiple scattering calculations [33] give much better agreement with the data at the angles between 60° and 130°. The differential cross section o f dp-elas tic scattering at the deuteron kinetic energy o f 880 M eV is presented in Fig. 2 as a function o f the c.m. scatter ing angle. The full circles and squares are the data from refs. [34] and [35], respectively. The dashed and solid lines are the results o f the calculations performed within relativistic multiple scattering model [33] w ithout and with taking into account the rescattering, respectively. 0* One can see a reasonable agreement betw een the calcu lations [33] and the experimental data [34,35] in the vicin ity o f the ''cross section minimum". One o f the reasons of some discrepancy in this region can be 3N SRCs, which are not included in the calculations. These SRCs can be responsible for the deviation betw een the calculations [31] and data on the analyzing powers [24,25] also.
The shape o f the differential cross section for the dpelastic scattering at 500 M eV obtained at ITS at Nuclotron [16] is in good agreement w ith the RCNP data [11]. It is planned to perform the systematic measurements o f the dp-elastic scattering cross section and analyzing powers at the energies 200-500 M eV/nucleon at ITS.

Energy dependence of the dpelastic scattering analyzing powers
The dependences o f the tensor A yy and vector A y analyz ing powers in dp-elastic scattering obtained at the fixed angles o f 60°, 70°, 80° and 90° in the c.m. as a function o f transverse momentum p T are shown in Fig. 3 and in Fig. 4, respectively. The open and solid symbols represent the data obtained at RIKEN, Saclay, ANL [8][9][10][36][37][38] and at Nuclotron [24,25], respectively.
The The change o f the sign is also observed for the vec tor A y analyzing power values at p T ~600-700 MeV/c at large angles in the c.m. A y has small negative values at low p T ■ but it achieves large positive values at p T higher ~700 MeV/c. It should be noted that large positive val ues o f the single spin asymmetry is observed in p p -elastic scattering at high energies and large p T (so called Krisheffect [40]). For dp-elastic scattering such effect is ob served at rather low p T. Further precise measurements are required to understand the reason o f such behavior.
The study o f the energy dependence o f the dp-elastic scattering analyzing powers at large p T is one o f the tools to study spin effects in cold dense matter.

dpnonmesonic breakup
The study o f dp-breakup reaction in different kinematic configurations gives an opportunity to select the regions of phase space where the observables are sensitive mostly to 2NF or 3NF. While the breakup data at the energies o f 65-135 M eV/nucleon [41][42][43][44] are quite systematic, the lack of the experimental information exists at higher energies. The predictions o f the polarization observables and cross sec tion for dp-non-mesonic breakup at 400 M eV for different kinematic configurations o f the final protons are given in ref. [45,46]. The observables for some kinematic config urations demonstrate strong sensitivity to the contribution o f 3NF. The dp-non-mesonic breakup reaction will be inves tigated at ITS at Nuclotron using A E -E techniques for the detection o f two final protons. Monte-Carlo simulation shown the feasibility o f such techniques for the energies Td <500 M eV [47]. Each detector consists o f two scin tillation counters: the first and the second ones are with 1 cm and 20 cm scintillators in length, respectively. The diameter o f the /•'-counter scintillator is 10 cm. The use 8-10 A E -E detectors simultaneously will allow to mea sure the observables for many kinematic configurations. The results on the amplitudes signals correlation for two E detectors obtained during beam test run in June 2008 at ITS using 2.3 GeV deuterons [17] are presented in Fig. 5. The measurements will be performed at the energies below 250 M eV/nucleon at the same time with the measurements o f dp-elastic scattering. However, additional time will be required to estimate reliably contribution from the carbon content o f ('H i target. The measurements o f the cross sections o f dp-elastic scattering and dp-nonmesonic breakup can be done with the current unpolarized ion source. The realization o f the spin program at ITS can be started with the intensity o f the POLARIS (~ 2 • 10s ppp) [27] maintained from the present value by the recovering o f the intensity losses during the injection into Nuclotron ring. The energy scan o f the dpelastic scattering observables can be done w ith new high intensity PIS [23].

Measurements at extracted beam
The goal o f the :'Hc(c/, /?)4Hc reaction study at Nuclotron-M is to understand the reasons o f the long staying puzzle, namely, the behavior of the tensor analyzing power T2o in dp-backward elastic scattering [48,49]. While t2n data in ed-elastic scattering obtained at JLAB [50] and T2n data in dp-inclusive breakup [51,52] can be explained by us ing the conventional deuteron structure functions and ad ditional to the B om approximation mechanisms, the T2o in dp-backward elastic scattering demonstrate unexplained strange structure at the internal momentum k ~0.3-0.5 GeV/c in the vicinity o f the D-wave dominance in the deuteron.
The experiments performed at RIKEN at the energies below 270 M eV have shown that the polarization correla tion coefficient for the :'Hc(c/, /?)4Hc reaction may be a unique probe to the D-state admixture in deuteron [19]. The usefulness of this observable to investigate the D-state admixture is at tributed to the strong spin-selectivity in neutron capture process by 3He nucleus, i.e., spins o f transferred neutron and 3He must be anti-parallel to each other in order to form 4He in the final state. In the B om approximation, the ex pression for Cu is proportional to the D-state fraction in deuteron as where u and w are the S-and D-state wave functions of deuteron in momentum space. This is a marked contrast to T-jo and k0 for dp backward elastic scattering which in clude S-and D-state interference term (//«'-term) together with a w2 -term. It is thus expected that C// may be a can didate to provide an information on the deuteron structure complementary to those from T20 and k,, obtained in dpbackward elastic scattering [48].
Tkin, MeV clei at short intemucleonic distances. However, the calcu la tio n s^] fail to reproduce the data. The reason o f the discrepancy can be in the non-adequateness o f the 3Nbound state spin structure and/or more complicated reac tion mechanism. The multiple scattering calculations are in progress now [33].  [53]. The curves are the calcu lation w ithin one-nucleon-exchange approxim ation [33].
Tensor analyzing power T20 , spin correlation ( )NI and polarization correlation coefficient C// for the 3He(<i,/>)4He reaction are shown in Fig. 6. Solid lines in the figures represent calculations based on an impulse approximation proposed in Ref. [20]. In the calculation, the Fermi m otion in the target nucleus is taken into ac count [21]. The full symbols are the data obtained at RIKEN [21]. The open squares show the expected preci sion for the data at Nuclotron-M.
The m ain goal o f the experiment is to obtain the data on C/j in the energy region o f 1.0-1.75 GeV, where the con tribution from the deuteron D-state is expected to reach a m aximum in one-nucleon exchange approximation, to ob tain new information on the strange structure observed in the behavior o f T20 in the dp-backward elastic scattering and to realize experiment on the full determination o f the matrix element o f the 3Hc(c/, /?)4Hc reaction in the model independent way. These data will help us also to under stand the short-range spin structure o f deuteron and effects o f non-nucleonic degrees o f freedom. For these purposes polarized deuteron beam from new PIS [23] and polarized 3He target developed at CNS o f Tokyo University [22] and modified for present experiment at Nuclotron-M will be used.
The data on the analyzing powers in d(d, 'He)« and d (d ,3R )p obtained at 270 and 200 M eV [53] are shown in Fig. 7. The curves are the calculation within onenucleon-exchange approximation using standard deuteron and 3He(3H) wave functions [54]. The data demonstrate the sensitivity to the D /S waves ratio in these light nu- The measurement o f the tensor analyzing power T20 in the d(d, /?)3H and d(d, 'He)« reactions at the deuteron energies 1-2 GeV can be performed using the same exper imental setup as for the 3Hc(c/, p )4He reaction studies.

Polarized 3He target
Several modifications to the existing CNS spin-exchangetype polarized 3He target [22] have been introduced for experiment at Nuclotron-M.
A Fiber Array Packaged Laser(COHERENT FAP-79-30C-800-LB) was installed to improve the optical pumping efficiency. Small light emittance due to the introduction of the fiber provides large transmission efficiency through op tical elements and good parallelness o f the irradiated beam on the target cell.
Correction coils to control the magnetic field homogenity has been introduced. The coils are placed inside o f larger Helmholtz coils which generate a homogeneous holding field o f ~ 15 G. The purpose is to extend the area o f the field homogeneity better than 10-3 cm -1 to coverthe enlarged target cell size o f 30 cm.
A diagnostics system to measure the 3He density and polarization accurately has established. Target density measurement with the pressure broadening method for the Rb D\ was introduced. By using the optical method, one can deduce the target density with high precision and high accuracy (relative error o f ~ 2%). New systems for the measurements o f the polarization o f the target using NRM and density o f the target has been manufactured, installed and tested.
The modified target is ready for the experiment at Nuclotron-M and has been used in the experiment on the polarization observables in the 3H e(p, p ) p X reaction stud ies at RCNP [55].

Polarized deuteron beam
To study the spin observables for the 4Hc(c/, /?)4Hc reac tion new high intensity PIS [23] w ith the full intensity o f ~ 2 • 10lu ppp is required. In this case one can mea sure 720 and ( simultaneously using polarized 3He tar get o f 30 cm thick. New source will allow to have wide num ber o f spin states w ith different combination of vector and tensor polarizations. In the experiment it is planned to use the modes w ith the following ideal values o f (p:.p::): (0,0), (0,-2), (2/3,0) and (-1/3,+1). The polarization of the beam will be measured by the ITS polarimeter based on the asymmetry measurement o f dp-elastic scattering [24,25]. '

Beam parameters and setup layout
The position o f the polarized 3He target will be ~ 8 m downstream o f the focus F3 o f the Nuclotron extraction line. The results o f the deuteron beam parameters measure ments performed at the energies betw een 1000 and 2000 M eV at the focus F3 o f the extraction line at Nuclotron [56] demonstrate that the beam parameters from Nuclotron are good enough to perform the experiment. However, it is necessary to modify the beam line to remove additional m atter along the extraction line to reduce the multiple scat tering o f the initial beam.
The detection system will be placed downstream focus F5 o f the VP1 beam line. Calculations for new magnetic optics have been performed [57]. The emittance o f the pri mary beam assumed is 10-207T mm-mr, the size o f the beam (2cr) at the target is about 0.5 cm both in the A 'and Y direc tion. The fields in the magnetic elements correspond to the momentum o f the proton from the reaction 3Hc(c/, /?)4Hc. The primary deuteron beam and secondaries are separated by the magnet w ith the bending angle o f ~140 mr placed upstream focus F4. Optical calculations show that the size o f the secondary beam in the focus F5 is 2-3 cm. The m o m entum and angular acceptances are A p /p = +4% and ~3 m sr (4<T"i<T"j. respectively. The angular acceptance can be increased in approximately 2-3 times by the use o f the lenses w ith larger diameter downstream the target. In the experiment it will be necessary to select protons against background deuterons w ith the same momentum, on the one hand, and to provide a good momentum reso lution to select protons from the 3Hc(c/, /?)4Hc reaction, on the other hand.
The setup will consist o f analyzing magnet, scintilla tion counters and drift chambers. The scintillation counter and a set o f drift chambers is placed at the focus F5 up stream the analyzing magnet. The second set o f the drift chambers, trigger counters and scintillation counters hodoscope are placed downstream the magnet. The size of the drift chambers placed in front o f the analyzing mag net can be about 10x10 cm2 according the calculations for magnetic optics [57].
The Fast VME based DAQ system will be used for the data taking. However, in the case o f large yield o f deuterons this background can be suppressed partly by the second level trigger based on the measurements o f the particles time-offlight. The preparation o f the time-of-flight counters [58], DAQ and HV systems [17] is in progress.

Polarimetry at Nuclotron-M
The spin part o f D S S -project requires good knowledge o f the deuteron beam polarization and its permanent mon itoring during data taking. It crucial also to establish a po larimetry suited for a vector-tensor mixed polarized beam provided by new LHEP PIS [23]. In the framework o f D S S -project new polarimetry scheme at Nuclotron-M will be established. The basic po-larimeter in this scheme is the polarim eter at ITS with the dp-elastic scattering at backward angles (8cm > 60°) at the energies 270-2000 M eV as the analyzing reaction [16]. This polarim eter has several advantages. Firstly, both vector and tensor analyzing powers for the reaction can have large values. Therefore, such polarimeter can allow to measure both vector and tensor beam polarizations and also the spin direction. Secondly, a kinematic coincidence measurement o f deuteron and proton w ith simple plas tic scintillation counters suffices for event identification. This is mainly due to a small background event rate, com pared w ith the forward angles. The use o f this reaction as a deuteron polarimetry at 140-270 M eV at large angles has been established at RIKEN [8][9][10].
The first calibration data obtained at 880 M eV and 2000 M eV demonstrated the feasibility o f such polarime ter [59]. The use o f large amount o f the scintillation coun ters allowed to cover wide angular range. The results on the vector and tensor beam polarizations for different spin modes o f POLARIS [27] by ITS polarim eter at 270 M eV at different angles in c.m. are shown in Fig. 8. The beam po larization values were evaluated from the dp-elastic scat tering asymmetries and values of the analyzing powers ob tained with high precision from absolute calibration o f the beam polarization at RIKEN [28]. The tensor and vector beam polarization values can be obtained w ith the preci sion better than 2%.
The ITS polarim eter will be calibrated in a wide energy range w ith reasonable energy step. The expected precision o f the analyzing powers calibration is 2-3% at the ener gies below 900 MeV. The results on the analyzing powers Ay, Ayy and.!.. in dp-elastic (H2) and quasi-elastic (CH2) scattering at 880 M eV presented in Fig. 9  At higher energies (above 1000 MeV) the carbon con tent o f CH2 gives m uch higher contribution. However, the results on the behavior o f the vector A y and tensor A yy analyzing powers for o f dp-quasi-elastic scattering ob tained at 2000 M eV [25] demonstrate the sizable values of these analyzing powers. This can simplify significantly the deuteron beam polarimetry at high energies. The expected precision o f the analyzing powers calibration is 3-5% at the energies betw een 1000 and 2000 M eV Three different polarimeters at external Nuclotron-M beam will be calibrated w ith the precision 3-5% at 1600 MeV. The vector polarimeter based on quasi-elastic p p -scattering [60] and located in focus F3 is necessary for the program with polarized nucleons. Deuteron inclu sive breakup polarimeter [61] with the detection o f protons with the momentum p p = 2/3 • p d can be useful for the ex periments where only tensor effects are studied. The use o f these both polarimeters simultaneously allowed to m ea sure both tensor and vector polarizations o f the extracted beam [39]. Such tensor polarimeter will be based on the use o f the magnetic spectrometer for the :'Hc(c/, /?)4Hc re action measurements.
New high energy polarimeter based on dp-elastic scat tering at forward angles, where both A y and A yy have large values [37,38], will be also located in focus F3. The dp-elastic scattering events will be detected by the kinematic coincidence o f deuteron and proton with plastic scintillation counters. The final selection o f useful events will be performed using amplitude and timing informa tion. The result o f the dp-elastic scattering events selec tion at 0J kih =8° and Td =2000 M eV via CH2-C subtrac tion o f timing spectra [62] is shown in Fig. 10. The open and shadowed distributions presented in the upper panel in Fig. 10 are the events obtained on CH2 and carbon tar gets, respactively, while the results o f CH2-C subtraction are presented in the bottom panel. The dashed lines are the prom pt timing windows for the final selection o f the dpelastic events.
The goal o f the D S S -project is to establish the polar ization standard for high energy deuteron beam polarime try at Nuclotron-M (initially based on the high accuracy dp-elastic scattering data obtained at RIKEN [28]).

Study of SRCs at NICA
New heavy ion and polarized particles collider NICA is planned for the energies -\jsNN ~4 -1 2 GeV and up to yfs ~27 GeV for dd-and p p -collisions, respectively. The serious advantage o f this facility is the availability o f po larized deuterons (neutrons). The main topics o f the spin studies at NICA is the spin content o f nucleon, nuclear and color transparency in spin observables, polarization effects in hyperon production, single and double asymmetries in meson production, N N and light nuclei short-range spin structure [63].
Deuteron and 3H e(3H) spin structure can be studied us ing two-arms magnetic spectrometer from d d -» p X [39], d d -» 3He«(3H p) [53], 3He3He -» p p X and other re actions. The deuteron internal structure in the dd -» p X process can be probed at NICA energies up to p T ~2-3 GeV/c, where different models predict significantly differ ent behavior o f the cross section [64]. The results o f the cross section data in the d p -» p X reaction calculations for laboratory frame at P d=40 GeV/c [64] using standard [30] and covariant DWF [65] for different proton emission angles are shown in Fig. 11 and Fig. 12, respectively. For collider mode such calculations correspond to yfs ~5.3 GeV/c2 and proton emission angles around 90° w ith re spect to the beam direction. The results strongly deviate for the calculations based on the use o f the standard and co variant DWFs [64] as well as from the constituent counting rule prediction [66,67]. The cross section data for deuteron breakup reaction at these energies are sensitive also to the problem o f hidden color in nuclei via the measurement of the cross section ratio for N (d, p n +)X and N (d, p )X pro cesses [66].
NICA will provide the opportunity to measure tensor analyzing power A yy and polarization transfer coefficient K v y in deuteron inclusive breakup w ith the proton emis sion at large p T. The data on the tensor analyzing power  Fig. 13 a), b), c) and d), respectively. The figure p in G eV/C Fig. 11. The calculations for the dp -h> p X reaction cross section a tP^= 4 0 G eV /c ( -\fs ~5.3 G eV /c2) for different proton em ission angles [64] in mr using C D -B onn D W F [30]. Note, that the same features are observed in the behavior o f. I,,,, in dp-elastic scattering at large p T (see Fig. 3).  The data obtained at p T -5 5 0 MeV/c are in a good agree ment with the calculations by using covariant DWF [65]. At higher p T A yy data have negative values, while the the ory predicts a positive sign in the range o f measurement Therefore, the A yy data clearly demonstrate the depen dence on two internal variables, xF and p T (or their combi nations). However, the use o f the deuteron structure func tion that depends on two variables [65] does not allow to describe the data. The measurements o f the tensor analyz ing power A yy and polarization transfer coefficient K y y in deuteron inclusive breakup, dd -» p X , at p T >1 GeV/c at NICA is feasible and can bring new information on the spin dependence o f 2N SRCs.
The collider mode gives very serious advantage to study 2N and 3N SRCs in nuclei from the A (p, p p )X and A (p , p n )X processes because o f large coverage o f the phase space for the correlated nucleon pairs in the laboratory sys tem. Color transparency can be studied in N (d ,p p )n and A ( d ,p p )X collisions [69] by the detection o f two protons at large transverse momenta. These studies can be compli mentary to U-70 and J-PARC scientific programs.