Differential cross section in deuteronproton elastic scattering at

Differential cross section in deuteron-proton elastic scattering at 1. 25 Ge. V/u P. Kurilkin, A. Kurilkin, V. Ladygin, T. Vasiliev LHEP-JINR For the HADES collaboration October 3 -7, 2011 in Rez/Prague, Czech Republic

Outline Introduction Data analysis • dp- elastic events selection • dp- elastic scattering simulation at 1. 25 Ge. V/u • Efficiency and acceptance correction • Preliminary results Conclusion 2

dp elastic scattering at the energy 270 Me. V NN Forces only NN interaction: CD-Bonn, AV 18, Nijmegen I, II & 93 NN + TM’(99) 3 NF NN interaction: CD-Bonn, AV 18, Nijmegen I, II NN + Urbana IX 3 NF NN interaction: AV 18 Relativictic calc. (AV 18) Nonelativictic calc. (AV 18) N. Sakamoto et al. , Phys. Lett. B 367, 60 (1996) H. Sakai et al. , Phys. Rev. Lett. 84, 5288 (2000) K. Sekiguchi et al. , Phys. Rev. C 65, 034003 (2002) K. Ermish et al. , Phys. Rev. C 68, 51001 (2003) K. Sekiguchi et al. , Phys. Rev. Lett. 95, 162301 (2005) 3

nd and pd elastic scattering measurements at the energy of 250 Me. V Calculations even including 3 NF underestimate the data at Θc. m ~110 -180 deg Relativistic calculations improve the fit of the data only at Θc. m >160 deg H. Sakai, FB 18, Santos, Brazil, (2006) Y. Maeda et al. , Phys. Rev. C 76, 014004 (2007) K. Hatanaka et al. , Phys. Rev. C 66, 044002 (2002) 34

World data: N. E. Booth et al. , Phys. Rev. D 4 (1971) 1261 J. C. Alder et al. , Phys. Rev. C 6 (1972) 2010 Relativistic multiple scattering model calculation: N. B. Ladygina, Eur. Phys. J, A 42 (2009) 91 Red circles are the preliminary LHEP-JINR results: DSS-project at Nuclotron. 5

HADES experiment at SIS 18, GSI Spectrometer with … High geometrical acceptance Full azimuth, polar angles 18˚ - 85˚ Pair acceptance 0. 35 High invariant mass resolution (2. 5% at / pole mass) Low-mass tracking (superconducting toroidial magnet & multi-wire drift chamber (MDC), single cell resolution 100 mm) FW Powerful PID capabilities: d/p/K/p/e RICH, TOF/TOFino, Pre-Shower, FW hodoscope: added 2007 High background rejection & rate capability, dedicated LVL 2 trigger: LVL 1: charge particle multiplicity LVL 2: single electron trigger Schematic view of the HADES spectrometer 4 6

dp elastic events selection at 1. 25 Ge. V/u. The dp- elastic events candidate selection: 0. 22 < tanθ 0 * tanθ 1< 0. 4, ||φ0 - φ1|-180| < 5° The angle-momentum distribution for dp - elastic scattering candidates compared with kinematical predictions. 7

Momentum and angular resolution for deuterons Uniform single tracks distribution (p, cosθ, φ) in the laboratory frame. 8

Momentum and angular resolution for protons Uniform single tracks distribution (p, cosθ, φ) in the laboratory frame. 9

Graphical cuts for the dp- elastic event selection at 1. 25 Ge. V/u The angular-momentum distribution for dp- elastic scattering candidate. Blue and red contours are the graphical criteria to the deuteron and proton selection. 10

Simulation of dp- elastic scattering at 1. 25 Ge. V/u The pd- elastic cross section data versus scattering angle in c. m. s. at 1 Ge. V. G. W. Bennet et al. , Phys. Rev. Lett. 19, 387 (1967) The angular distribution used for simulation of dp- elastic scattering at 1. 25 Ge. V/u. The cross section data was fixed at the cosθ* > 0. 886. 11

Simulation of dp elastic scattering at 1. 25 Ge. V/u Correlation between difference of 180 -|Δφdp| and tanθd * tanθp The distribution of the tanθd * tanθp for dp- elastic scattering at 1. 25 Ge. V/u 12

Selection of the particles in the region where graphical cuts of deuteron and proton overlap. Real data Simulated data The experimental time difference distribution between two tracks. 13

Quality of the dp elastic events selection The distribution of the 180º - (θd*+θp*) for the angular region 73º ± 3º (Left panel) and for the 105º ± 3º (Right panel) in the c. m. s. 8 14

The simulation results of the dp elastic scattering at 1. 25 Ge. V/u Geant. Input Accepted 18°< θlab<85° Reconstructed 18°< θlab<85° Distribution of the dp- elastic scattering yield as a function of the cosθ*. Black, blue and red histograms are the distribution for dp-elastic scattering using as the geant input, accepted and reconstructed, respectivelly. Acceptance and efficiency reconstruction coefficients for the dp- elastic scattering events. 15

Efficiency and acceptance correction for dp elastic scattering at 1. 25 Ge. V/u • • rk. Mult ≥ 2 |Δφdp| < 5º 0. 17< tanΘ*d*tanΘ*p < 0. 4 18º < Θlab [d, p] < 85º • is efficiency and acceptance corrected http: //hades-wiki. gsi. de/pub/Sim. Ana/ Normalization. For. Pp. And. Dp/pp_elastic 260109. pdf 16

Differential cross section of dp elastic scattering at Ge. V/u region y r a in im l e pr HADES results Experimental data: E. Winkelman et al. , Phys. Rev. C 21, 2535 (1980) G. W. Bennet et al. , Phys. Rev. Lett. 19, 387 (1967) E. Coleman et al. , Phys. Rev. Lett. 16, 741 (1966) N. E. Both et al. , Phys. Rev. D 4, 1261 (1971) E. Gulmez et al. , Phys. Rev. C 5, 2067 (1991) 17

Differential cross section data for dp elastic scattering at fixed scattering angle in the cm. s-16 Experimental data: Constituent counting rules: E. Winkelman et al. , Phys. Rev. C 21, 2535 (1980) G. W. Bennet et al. , Phys. Rev. Lett. 19, 387 (1967) E. Coleman et al. , Phys. Rev. Lett. 16, 741 (1966) N. E. Both et al. , Phys. Rev. D 4, 1261 (1971) E. Gulmez et al. , Phys. Rev. C 5, 2067 (1991) V. A. Matveev, R. M. Muradyan and A. N. Tavkhelidze, Lett. Nuovo Cimento 7, 719 (1973) Yu. N. Uzikov, JEPT, Lett. , 81, 303 (2005) 18

Summary • The preliminary results on differential cross section for dpelastic scattering at the energy of 1. 25 Ge. V/u are obtained. • The HADES data on dp- elastic scattering at are in the reasonable agreement with the world data. Outlook: • Data analysis with hydra 8. 21. • Obtain the final results on the differential cross section in dp elastic scattering at Td=2. 5 Ge. V. • Estimation of the systematic errors of the differential cross section measurement. 19

Many thanks to A. Rustamov, K. Lapidus, T. Galatyuk, G. Agakishiev, V. Pechenov, O. Pechenova, M. Lorenz and other people who helped us in our analysis!!! 20

Thank you for your attention!!! 21

Short internucleonic distances When the distances between the nucleons are comparable with the size of the nucleon, the nucleon-nucleon interaction is nonlocal. Fundamental degrees of freedom in the frame of QCD are the quarks and gluons. These degrees begin to play a role at the internucleonic distances comparable with the size of the nucleon. (∆∆, N*N*, 6 q components in the deuteron) At high energy s and large transverse momenta pt the constituent counting rules are working. For the binary reactions: (Matveev, Muradian, Tavkhelidzhe, Brodsky, Farrar et al. ) 22

Quark degrees of freedom Yu. N. Uzikov (JEPT Lett, 81, pp. 303 -306, 2005) For the reaction dd → 3 Hen For the reaction dp → dp The regime corresponds to CCR occurs already at Td ~ 500 The investigation of the energy dependence of. Me. V the cross section in dp elastic scattering is very desirable to obtain the information on the deuteron internal structure. 23