The Program: First - PowerPoint Presentation

The Program: First msrmnts of tensor observables in scattering expt’s (mid-80’s)(iT11), T20, T21, T22Msrmnts mostly in elastic channelSome also in absorption & breakupDirect msrmnt of tgt tensor polarizationIndependent of usual NMR techniquesRF burning results also studiedBrief description of tgts usedexpt’l techniquesphysicsDescription of analysis techniques   Tensor Target Polarization at TRIUMF 1929-2014 Erich Vogt TRIUMF director1981-1994 G. Smith, JLab

Use Madison conventionProceedings of the Third International Symposium on Polarization Phenomena in Nuclear Reactions, Madison, 1970, edited by H. H. Barschall and W. Haeberli (University of Wisconsin, Madison, 1971).P. Schwandt and W. Haeberli, Nucl. Phys. A110, 585 (1968).Target vector (pz) & tensor (pzz) polarizationMsrd tensor polarization (t20) of recoil d : unpolarized tgt 3He( ,p)4He polarimeter to analyze recoil d Vector (iT11) & tensor (T20, T21, T22) analyzing powers. Composite observables & elastic: tensor polarized target   Nomenclature

Brillouin formula: With I=1, x=( μ H)/(2kT) Likewise, , peak asym And νD=d NMR ν (16.6 MHz) & Ts=d spin temp   Some Basic Formulas

x = (μH)/(2kT)µ = 2.703x10-14 MeV/Tk = 8.617×10−11 MeV/K 3 He fridge: p z ~0.25 3 He/ 4He fridge: pz~0.5  Plots Dilution refrigerator 3He refrigeratorNot much to work with!

SIN LAMPF SIN SIN LAMPF

Perform 1st expt. ever using a tensor polarized target! , with longitudinal We thought we were pioneering this back in 1984Knew about some CERN tech notes on pol tgts deBoer etal PL46A, 143 (1974), Ninnikoski, Scheffler , Guckelsberger & Udo NIM137, 415 (1976), Hamada etal NIM189, 561 (1981) No double scattering/recoil polarimeterFewer systematic errors: msr xsec ratiosDevelop a large dΩ detection system with lots of θ multiplicityCrucial to insure to suppress other Tij Used a split counter with field on/off to do this, lasers & mirrorsBe damn sure you can msr pzz   How to resolve this?

Where the are the Wigner d functions, and u sing either calculated values of T 21 & T 22 ,orlimiting values . Coordinate system rotation needed becauseT20 z along incident beam, but t20 z along d momentum.This rotation mixes in small components from T 21 & T22 .  

T20 First Results SIN t 20 LAMPF t 20 TRIUMF t 20 TRIUMF T20Full calcNo P11 abs

Conditions:Dilution fridge ~ 120 mK s.b. 50 mK!Longitudinal 2.5 T sc split pairΔB/B ~ 10-4, persistent modeνμwave 70.820 GHz (3h @ 1 mW)νNMR ~ 16.660 ± 0.256 MHz1 mm φ deuterated butanol beads 95% deuterated n-butyl alchohol5% D2O doped with EHBA-( CrV)Teflon cell 16x16x5 mm3P z=0.333 ± 0.015 Pzz=0.085 ± 0.0083 techniques used to msr p zz: pz = P(N) A(D)/A(N) DIRECT MSR OF P ZZ    

Area & R techniques rely on assumptions:D quadrupole moment contribution negligible 20 kHz vs 16 MHz @ 2.5 TBoltzmann dist. (equal spin temps)Kiss that goodbye with RF burningpzz deduced from msrd pzpzz is bloody small…NMR system linear over a wide rangeIn gain (~3 orders of magnitude)In frequency too (16.6 ± 0.3 MHz @ 2.5 T)pzz is abstract. Can we trust it?

BENCHMARK usual NMR methods to msr pzz by direct msrmnt:T20 at 90º(cm) in  pp “known” virtually model independently, and is large, maximal in fact: , where σ = Yield/(N beamε)Get T20 2 ways:Msrd Ayy in pp  π d at 90º: A yy =-0.86±0.04 at Tp=447 MeV (NPA415, 391 (1984))Then T 20 = -1.27 ± 0.05PWA & 3-body Fadeev calculationsIf a2 (feeds the 1D2 pp wave) dominates (as expected on resonance):  Novel DIRECT msr of pzz

Msrd Ayy in ppπ dFadeev Our PSA beam C 4 D 9 OD C 4H9OH ( bkg)foreground minus bkgBKG: QF abs on 12C Since no abs on H, this is a perfect bkg tgt!Flinders PSApzz ExperimentTook T20= -1.28 ± 0.03after accounting for ±2.5º angular acceptance

Analyzed πd  2p data using:TOF: pzz = 0.098 ± 0.024Coplanarity: pzz = 0.100 ± 0.022Using NMR techniques:NMR Areas: pzz = 0.083 ± 0.008NMR peak ratios: pzz = 0.095 ± 0.008RF pedestal burning msrd in frozen spin mode (no μw) over 18h after burning. NMR p zz unknown:TOF: pzz = 0.10 ± 0.017 Coplanarity: pzz = 0.11 ± 0.018Consistent with unburned Either no enhancement, or relaxation times too shortBenchmarking p zz Results p zz ? ? ?ok

Saw no effectWithin our uncertaintiesAlso none from holding fieldBut pzz was very smallHazy on what NMR predicted burned pzz wasI think it was Δpzz ~ 0.05 (see TRI-PP-86-027 by Delheij, Healey & Wait)Really no effect? Msrd burned/unburned = 1.08 ± 0.30A larger ratio if comparing burned to NMR… grasping at straws thoughAfter burning, msrd average polarization over an 18h periodDid not investigate shorter time periodsWas frozen spin the problem?May have had better rslts with MUCH higher B (longer relaxation times)Need to know pzz during the entire physics msrmnt Problematic if burned pzz(time) is hard to msr More on Burning NMR π d 2p unburnedAvg of πd2pburned 2.5 T burned 1.25 T burned

TRIUMF Tgt Grp

Next: T21

With Euler angles = polar angle between incident beam (z-axis) and = angle between y-axis ( ) and projection of on x-y plane To emphasize T 21  take = 54.7° to kill T20 term and = 90° to kill iT11 termBut had to pick =45° due to magnet geometry How to get at T21? 

take =0° to eliminate all other Tij undefined take = 54.7° to kill T 20 , =90° to kill iT 11. Some T22.We had to take =45° which mixes in some T 20 (& T22)take =90° to eliminate T21 Take =0° to maximize iT11 & T22 terms. Some T22.      Choice of Euler Angles Determines the Observables Can separate T ij after measuring , composite obs. , &  

With = 45° and = 90° :   Initial Results   Small by   Small at back angles C 4 D 9ODC4H9OHpz=0.47TEpzz=0.17

More on T20 & T21pzz 0.10 up to 0.17pz =0.47

Better without the P11 !Some ResultsFull 3 body(Flinders)Same, but w/o P 11

The P11 Phase Shift NN – πNN system: hard to couple to 2 body cuz π can absorb on one N and be emitted by the other. Soln: treat abs. via the P11 πN interaction3-body calculations sensitive to cancellation of the pole (true π absorption) & non-pole (multiple scattering w/o absorption) in the P11 πN phase shift.Problem: cacl’s w/o the P11 generally compare better to data!Soln (Jennings, PLB205, 187 (1988): Pole term Pauli blocked. Missing diagrams (different time ordering) cancel ones responsible for the Pauli blocking & improves agreement! cancels 1b & 1c missing

Propandiol: C3D6(OD)2 & C3D6(OH)2 92% deuterated, doped with CrV1 mm beads in a 0.1 mm thick 5x18x18 mm3 brass cell4 mW cooling power 50 mK dilution fridgeUp to pz=-0.48 (pzz =0.18) after 12 hBack to SIN/PSI 150h @ 0.83T

Till now, only msrd (pol)/σ(unpol)What about AND ?Use both  reduce systematic errors Rewrite general eq. as σ(pz ) = A + Bpz + Cp zz Where A = σ0 , B = σ0aViT11, & C = σ0 a TTAnd for T=T20, for T= 21, & aV~0 If B≠0  pz is wrong, or tgt/B misaligned Extraction Method 2: FittingT2021 

Take data in sequence:...,, Adding & subtracting: Likewise for Construct matrices of for each pair ( ie like , ). Ex: 5 pairs of , , 5 of , 5 rows & 5 columnsDiag elements are time ordered pairs Weighted avg of these is the resultRow & column avgs  consistency Eliminates electronic drifts   Extraction Method 3: Matrices Diagonal m atrix elements & result = w eighted avg Column averages Row averages 294 MeV, θ π =151°

Completing the suite:   With normal to scattering plane (vertical)   with α =90º & β =0º So you get iT 11 from the difference of σ±, & τ22 simultaneously from the sum -48.2%+41.7%134º76º400h @ 2.5T

  &   134º 76º    

Tensor polarized targets have been used successfully to measure iT11, T20, and in π scatteringWith pz=0.48, get pzz=0.18RF burning was a bust (for us) within our (large) uncertaintiespzz direct msrmnt to confirm NMR techniquesTarget alignment ( ) with crucial to select T ij Various methods to extract T ij using But can make do just fine with just σ(pol) & σ(unpol) Caveats: Beam heating negligible with pionsMy b1 opinion: dangerous to bank on rf burningrf burning probably still worth investigating further/better But essential to find a way to benchmark it outside NMRBackup plan with p zz ~0.2 (you know you can do this)   Summary