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Breakup reaction for polarimetry of t ensor polarized deuteron beams. A.P. Kobushkin Bogolyubov Institute for Theoretical Physics Metrologicheskaya str. 14B 03680 Kiev, Ukraine E.A. Strokovsky Laboratory of High Energy Physics Joint Institute for Nuclear Research
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Breakup reaction for polarimetry of tensor polarized deuteron beams A.P. Kobushkin Bogolyubov Institute for Theoretical Physics Metrologicheskaya str. 14B 03680 Kiev, Ukraine E.A. Strokovsky Laboratory of High Energy Physics Joint Institute for Nuclear Research 141980, Dubna, Russia Based on talk given at the “SYMMETRIES AND SPIN (SPIN-Praha-2012)” Conference, Prague, July 1 - 8, 2012; JINR preprint Е2-2013-14, Dubna, JINR, 2013. See also A.P.K. and E.A.S., Phys. Rev. C 87 (2013), 024002 E.A.Strokovsky,Dubna, 18.03.2013
Common interest to the lightest nuclei structure at short distances or high relative momenta between constituents resulted in lack of attention to behaviour of spin-dependent observablesat long distances or at small relative momenta. To avoid this bias we paid special attention to behaviour of the observables at this small relative momenta region as well. The goal of this talk is to demonstrate that: Deuteron breakup at 0o can be used for local polarimeters at SPD as well as MPD. Polarization monitoring can be easily realized. Existing data obtained with polarized deuterons contain more physical information than it was extracted so far. E.A.Strokovsky,Dubna, 18.03.2013
Selected experimental data concerning the deuteron structure (hadron probes; reminder). E.A.Strokovsky,Dubna, 18.03.2013
Total cross section for deuteron-proton scattering (intermediate energy region) E.A.Strokovsky,Dubna, 18.03.2013
Breakup (d,p)X at 0o, backward elastic scattering Cross section Tensor analysing power Polarization transfer coefficient (from vector polarized deuteron to proton) The key tool: polarized deuteron beams in Dubna and Saclay. Light cone variable E.A.Strokovsky,Dubna, 18.03.2013
Deuteron breakup and the D2 parameter for deuteron E.A.Strokovsky,Dubna, 18.03.2013
Definition for deuteron in literature: At small k: E.A.Strokovsky,Dubna, 18.03.2013
M – nucleon mass, B – binding energy of deuteron Knutson&Haeberli (1976): D2 = (0.432 0.032); W. Gruebler et al (1980): d = (0.0259 0.0007); k in Fm-1 k in GeV/c = -(22.19 0.82) when k is taken in GeV/c Dd2 is positive. (Instead of d many people often use notation d). E.A.Strokovsky,Dubna, 18.03.2013
Reminder: existing data on deuteron breakup (inclusive) E.A.Strokovsky,Dubna, 18.03.2013
Zoom at the next slide E.A.Strokovsky,Dubna, 18.03.2013
Deuteron breakup by protons (Z=1) Energy range: Tkin=2.1 GeV (Saclay, data tables publ. in 1987 & 1989), 7.4 GeV (Dubna, data tables publ. in 1996) Excluded from the fit E.A.Strokovsky,Dubna, 18.03.2013
Knutson&Haeberli (1976): 2D2 = (22.19 0.82) (k in GeV/c) W. Gruebler et al : (1980 ): 2D2 = (24.80 0.67) Our fit of the p(d,p)X data: 2D2 = (23.70 0.33) Theoretical value of d (or d) is around 0.0254 0.0259; experimental value (averaged) is 0.0256(4); what results in 2D2 = 24.51 0.38 Taking into account that: the used spectator model does not include some possible corrections (Coulomb first of all) and only statistical errors are taken into account and those were not a dedicated measurements of T20at low q (the main interest was to the high q region), the obtained value is in rather good agreement with existing data even without optimization of the q-range. The p(d,p)X reaction in GeV region can be used as additional source for data on d (or d) . E.A.Strokovsky,Dubna, 18.03.2013
From V.M.Krasnopol’sky et al, PhL 165B (1985) p.7: Potential: RSC d = 0.0262 2D2 = 25,09 RHC d = 0.0259 2D2 = 24,80 Yale d = 0.0254 2D2 = 24,32 Paris d = 0.0261 2D2 = 24,99 MSU (old) d = 0.0269 2D2 = 25,76 From E. Epelbaum, Braz. Journ. Ph., v. 35, p. 854. (2005): N3LO in chiral EFT: d = 0.0254 2D2 = 24,32 d = 0.0255 2D2 = 24,42 From http://nn-online.org/, NN potential by Nijmegen group: Nijm II: d = 0.02521 2D2 = 24,14 Nijm 93: d = 0.02524 2D2 = 24,17 Reid93: d = 0.02514 2D2 = 24,07 Our fit of the p(d,p)X (0o) data: 2D2 = (23.70 0.33) E.A.Strokovsky,Dubna, 18.03.2013
Effects of the Coulomb interaction (hints) E.A.Strokovsky,Dubna, 18.03.2013
Deuteron breakup by carbon (Z=6) A.P. KOBUSHKIN, YA.D. KRIVENKO-EMETOV, Ukr. J. Phys. 2008. V. 53, N 8, p.751 Dash-dotted line: quasi-impulse approx. Dashed line: multiple scatt. + Pauli principle for all constutuent quarks in deuteron; Full line: Coulomb interaction is added E.A.Strokovsky,Dubna, 18.03.2013
Deuteron breakup by carbon (Z=6) Tkin= 7.4 GeV (Dubna, data tables publ. in 1990 & 1996) E.A.Strokovsky,Dubna, 18.03.2013
Conclusions. Deuteron breakup with spectator proton detection at 0o at momentum in vicinity of pd /2 is very useful reaction for: (1) deuteron beam polarimetry at intermediate and high energies both for tensor polarization (energy independent, high figure of merit T202!) and vector polarization (proton polarization must be measured); (2) obtaining new experimental data about the deuteron asymptotic D/S ratio; experimental estimates of Coulomb effects in deuteron breakup; the Coulomb effects in T20 are (apparently) small. E.A.Strokovsky,Dubna, 18.03.2013
Thank you! E.A.Strokovsky,Dubna, 18.03.2013