Measurement of tensor analyzing powers in deuteron photodisintegration

1

Measurement of tensor analyzing powers

in deuteron photodisintegration

Dmitri ToporkovDmitri Toporkov

Budker Institute of Nuclear Budker Institute of Nuclear PhysicsPhysics

Novosibirsk, RussiaNovosibirsk, Russia

SPIN2004, Trieste, ItalySPIN2004, Trieste, Italy

October 15, 2004October 15, 2004

2

1. Introduction2. Physical motivation3. Experimental arrangement4. Polarized target5. Detector6. Results 7. Conclusions

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

3

Novosibirsk Electron-Deuteron CollaborationL.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, RussiaA.Yu.Loginov, A.N.Osipov, A.A.Sidorov and V.N.Stibunov

INR, Tomsk, RussiaR.Gilman

Rutgers University, Piscataway, NJ, USAE.R.Kinney

Colorado University, Boulder, CO, USAR.J.Holt and D.H.Potterveld

ANL, Argonne, IL, USAC.W.de Jager1 and H. de Vries

NIKHEF, Amsterdam, The NetherlandsS.L.Belostotsky, V.V.Nelyubin and V.V.Vikhrov

INP, St.-Petersburg, RussiaH.Arenhovel

IKP, Johanness Gutenberg-Universitat, Mainz, Germany 1Present address: TJNAF,Newport News, VA, USA


4

VEPP-3Energy : 2000 MeVLifetime : 14000 sAv. current : 100 mABunch : 0.7x0.3 mm

Novosibirsk electron-positron facility


5

Photodisintegration of polarized deuteron

eAngle is small

Photon is almost real

2 *020

* * 2 * *21 22

1 11 (3cos 1)

22

3 3sin 2 cos sin cos 2

8 8

{

}

ZZ

ddP T

d d

T T

Scattering angle is small, therefore q2 close to zero andphoton is almost real. Process is photodisintegration


6

Definition of kinematic variables for the reaction ( d, pn) in the center of mass frame


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

8

Top view of the internal target at VEPP-3 electron ring


9

Cryogenic Atomic Beam Source

Liquid nitrogen

Tenzor polarizationVector polarization

CryostatCryostat

Turbopump



ABS just before the installation at the straight sectionABS 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 8.2x1016 at/secThe measured target thickness 8x1013 at/cm2


12

The layout of the detector system, side view

A - tangstem convertorB - brass baseC - scintillation fibers


200x200x1000 mm

120x400x1000 mm

13

Asymmetry in elastic ed scattering at small transfered momentum, centered at = 9.3, Q = 0.105 (GeV/C)○ 2 2

At small momentum transfersT ≈ -√2/3 Q QQ = 0.2859 fm - deuteron static quadrupole moment

20

D

2D

2

e

At Q = 0.105 (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

20

LQ polarimeter feature


14

The average degree of targetpolarization during the run was found to be

+zzP = 0.378 ± 0.022

LQP


15

τ =8000sectarget

τ =20000secnotarget

Beam life-time in the VEPP-3 ring during the experiment


16

Charge accumulation during the experiment



Proton: F, E/E Neutron: F, charge veto

Kinematic correlations:p-n energyp-n polar angle

p-n azimuthal angle

18

Preliminary results on T20 with = 83-93 (full circles) and old data Phys.Lett. B302 (1993) 277 (open circles)


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

cmp

19

Preliminary results on T21 and T22 with =83-93 (full circles) and old data Phys.Lett. B302 (1993) 277 (open circles)


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

cmp

20

Preliminary results on T20, T21 and T22 measurement

E 25-45 MeV 45-65 MeV 65-100 MeV


K.-H.Schmitt and H. Arenhovel fullM.I.Levchuk full

21

Preliminary results on T20, T21 and T22 measurement

E 100-150 MeV 150-250 MeV 250-400 MeV


K.-H.Schmitt and H. Arenhovel fullM.I.Levchuk full

23

Part of Part of people, who did the experimentpeople, who did the experiment


Measurement of tensor analyzing powers in deuteron photodisintegration

Documents

Transcript of Measurement of tensor analyzing powers in deuteron photodisintegration