1 Measurement of tensor analyzing powers in deuteron photodisintegration Dmitri Toporkov Budker Institute of Nuclear Physics Novosibirsk, Russia SPIN2004, Trieste, Italy October 15, 2004

2 1.Introduction 2.Physical motivation 3.Experimental arrangement 4.Polarized target 5.Detector 6.Results 7.Conclusions Dmitri Toporkov Measurement of tensor analyzing powers SPIN2004,Trieste,Italy in deuteron photodisintegration

3 Novosibirsk Electron-Deuteron Collaboration L.M.Barkov, V.F.Dmitriev, M.V.Dyug, L.G.Isaeva, A.V.Grigoriev,B.A.Lazarenko, S.I.Mishnev, D.M.Nikolenko, I.A.Rachek, R.Sh.Sadykov, Yu.V.Shestakov, D.K.Toporkov and S.A.Zevakov BINP, Novosibirsk, Russia A.Yu.Loginov, A.N.Osipov, A.A.Sidorov and V.N.Stibunov INR, Tomsk, Russia R.Gilman Rutgers University, Piscataway, NJ, USA E.R.Kinney Colorado University, Boulder, CO, USA R.J.Holt and D.H.Potterveld ANL, Argonne, IL, USA C.W.de Jager 1 and H. de Vries NIKHEF, Amsterdam, The Netherlands S.L.Belostotsky, V.V.Nelyubin and V.V.Vikhrov INP, St.-Petersburg, Russia H.Arenhovel IKP, Johanness Gutenberg-Universitat, Mainz, Germany 1 Present address: TJNAF,Newport News, VA, USA Dmitri Toporkov Measurement of tensor analyzing powers SPIN2004,Trieste,Italy in deuteron photodisintegration

4 VEPP-3 Energy : 2000 MeV Lifetime : s Av. current : 100 mA Bunch : 0.7x0.3 mm Novosibirsk electron-positron facility Dmitri Toporkov Measurement of tensor analyzing powers SPIN2004,Trieste,Italy in deuteron photodisintegration

5 Photodisintegration of polarized deuteron Scattering angle is small, therefore q 2 close to zero and photon is almost real. Process is photodisintegration Dmitri Toporkov Measurement of tensor analyzing powers SPIN2004,Trieste,Italy in deuteron photodisintegration

6 Definition of kinematic variables for the reaction ( d, pn) in the center of mass frame Dmitri Toporkov Measurement of tensor analyzing powers SPIN2004,Trieste,Italy in deuteron photodisintegration

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8 Top view of the internal target at VEPP-3 electron ring Dmitri Toporkov Measurement of tensor analyzing powers SPIN2004,Trieste,Italy in deuteron photodisintegration

9 Cryogenic Atomic Beam Source Liquid nitrogen Tenzor polarization Vector polarization Cryostat Turbo pump Dmitri Toporkov Measurement of tensor analyzing powers SPIN2004,Trieste,Italy in deuteron photodisintegration

10 Dmitri Toporkov Measurement of tensor analyzing powers SPIN2004,Trieste,Italy in deuteron photodisintegration ABS just before the installation at the straight section ABS just before the installation at the straight section Magnetic pole tip field of superconducting magnet up to 4.8 T

11 Storage cell for polarized atoms Beam flux of polarized deuterium atoms 8.2x10 16 at/sec The measured target thickness 8x10 13 at/cm 2 Dmitri Toporkov Measurement of tensor analyzing powers SPIN2004,Trieste,Italy in deuteron photodisintegration

12 The layout of the detector system, side view Dmitri Toporkov Measurement of tensor analyzing powers SPIN2004,Trieste,Italy in deuteron photodisintegration 200x200x1000 mm 120x400x1000 mm

13 Asymmetry in elastic ed scattering at small transfered momentum, centered at = 9.3, Q = (GeV/C) ○ 22 At small momentum transfers T ≈ -√2/3 Q Q Q = fm - deuteron static quadrupole moment 20 D 2 D 2 At Q = (GeV/C) all 'reasonable' theoretical predictions for T contain within ±5% range 2 2 An absolute measurement of T performed at NIKHEF, further constraining models 20 LQ polarimeter feature Dmitri Toporkov Measurement of tensor analyzing powers SPIN2004,Trieste,Italy in deuteron photodisintegration

14 The average degree of target polarization during the run was found to be LQP Dmitri Toporkov Measurement of tensor analyzing powers SPIN2004,Trieste,Italy in deuteron photodisintegration

15 Beam life-time in the VEPP-3 ring during the experiment Dmitri Toporkov Measurement of tensor analyzing powers SPIN2004,Trieste,Italy in deuteron photodisintegration

16 Charge accumulation during the experiment Dmitri Toporkov Measurement of tensor analyzing powers SPIN2004,Trieste,Italy in deuteron photodisintegration

17 Dmitri Toporkov Measurement of tensor analyzing powers SPIN2004,Trieste,Italy in deuteron photodisintegration Proton:  F,  E/E Neutron:  F, charge veto Kinematic correlations: p-n energy p-n polar angle p-n azimuthal angle

18 Preliminary results on T 20 with = (full circles) and old data Phys.Lett. B302 (1993) 277 (open circles) Dmitri Toporkov Measurement of tensor analyzing powers SPIN2004,Trieste,Italy in deuteron photodisintegration K.-H.Schmitt and H. Arenhovel, Few-Body Syst. 7(1989)95 Yu.P.Melnik and A.V.Shebeko, PRC 48(1993)23  =1.2Gev ibid  =4m  M.I.Levchuk, Few-Body Syst. 19(1995)77

19 Preliminary results on T 21 and T 22 with =83-93 (full circles) and old data Phys.Lett. B302 (1993) 277 (open circles) Dmitri Toporkov Measurement of tensor analyzing powers SPIN2004,Trieste,Italy in deuteron photodisintegration K.-H.Schmitt and H. Arenhovel, Few-Body Syst. 7(1989)95 Yu.P.Melnik and A.V.Shebeko, PRC 48(1993)23  =1.2Gev ibid  =4m  M.I.Levchuk, Few-Body Syst. 19(1995)77

20 Preliminary results on T 20, T 21 and T 22 measurement E MeV MeV MeV Dmitri Toporkov Measurement of tensor analyzing powers SPIN2004,Trieste,Italy in deuteron photodisintegration K.-H.Schmitt and H. Arenhovel full M.I.Levchuk full

21 Preliminary results on T 20, T 21 and T 22 measurement E MeV MeV MeV Dmitri Toporkov Measurement of tensor analyzing powers SPIN2004,Trieste,Italy in deuteron photodisintegration K.-H.Schmitt and H. Arenhovel full M.I.Levchuk full

22 Dmitri Toporkov Measurement of tensor analyzing powers SPIN2004,Trieste,Italy in deuteron photodisintegration

23 Part of people, who did the experiment Dmitri Toporkov Measurement of tensor analyzing powers SPIN2004,Trieste,Italy in deuteron photodisintegration