1、projector testAPS-DNP 2019 Session DA:Probing the Gluonic and Quark Structure of MatterDA1.First Experiments with a Polarized Hydrogen Jet Target in RHICWilly Haeberli Department of Physics,University of Wisconsin-Madison DA Probing the Gluonic and Quark Structure of MatterMeasuring the Polarization
2、 of High-Energy Protons WHY?HOW?APS-DNP W.Haeberli,University of Wisconsin Chicago October 29,2019 K.Rith DIS 2019DIS of polarized HE leptons(e,m)from polarized nucleons atSLAC,CERN,HERA:Good agreement with two very different experimental methods.What accounts for the spin of the nucleon?APS-DNP W.H
3、aeberli,University of Wisconsin Chicago October 29,2019The(old)proton spin puzzle:Only(204)%of proton spinisaccounted for by spins ofquarks and antiquarks two 60 cm long Target-Containerswith opposite polarization superconductive Solenoid(2.5 T)3He 4He Dilution refrigerator(T50mK)Dipole(0.5 T)COMPAS
4、S polarized LiD targetEm m=160 GeV,pB -76%1.8*107 m m/sec(time ave)polarized LiD-target,pT 50%Luminosity:5*1032 cm-2 s-1Polarization:50%Dilution 40%HERMES internal targetFactor 100 gain fromuse of“storage cell”(S.Price)Polarized H,D injection To H,D polarimeter.Pure polarised gas targets:H,D,target
5、polarisation:pT 85%target thickness 1014 H/cm2Luminosity:6*1033 cm-2 s-1(D 50 mA)spin reversal every 120 sec0.1 Gluon?Orbital?Gluons:key contributor to the proton spin?Maci nt osh PI CTi mage f ormati s not support edslide adapted fromW.Vogelsang(BNL)Gluons:Measurements of DG/GxgAPS-DNP W.Haeberli,U
6、niversity of Wisconsin Chicago October 29,2019 from F.H.Heinsius,COMPASS Collab-DIS April 2019 PHENIX and STAR at RHIC will measure DG by collisions of longitudinally polarized HE protons-ALLRHIC:c.m.energies up to 500 GeV Ma c i nt os h PI CTi ma ge f or ma ti s not s uppor t e dRHIC experiments wi
7、ll measure DGBUT HOW DOES ONE KNOW Pbeam?Colliding polarized protons couple directly to gluons(rather than via charge)-measure parton asymmetries.Measure polarization of gluons through g,jets,p pis,heavy quarks.G.Bunce DUBNA-SPIN-03The RHIC Complex 50 s 500 GeV STARPHENIX Spin Rotators20%SnakePHOBOS
8、 SiberianSnakes present performance:L=4x1030s-1cm-2,Pbeam 40%5%Snake0.7 1011 pol.protons/bunch56 bunchesBRAHMS&PP2PPAGSLINACBOOSTERPol.Proton SourceSiberian Snakes200 MeV polarimeterRf DipolesAGS p-C polarimeterRHIC p-C polarimetersabsolute pppolarimeter+-+-+-+-+RHIC What mechanism is sensitive to P
9、 at high energy?Need to know analyzing power A.M a c in to s h P IC Tim a g e fo rm a tis n o t s u p p o rte dMaci nt osh PI CTi mage f or mati s not suppor t edMacintosh PICTimage formatis not supportedM a c in to s h P IC Tim a g e fo rm a tis n o t s u p p o rte dMeasuring polarization of proton
10、 beam Maci ntosh PI CTi mage formati s not supportedReverse P to eliminate instrumental asymmetryMaci ntosh PI CTi mage formati s not supportedAPS-DNP W.Haeberli,University of Wisconsin Chicago October 29,2019Magnetic Moment ScatteringMott(1929),J.Schwinger(Phys.Rev.73,1948)+m mm mAnalyzing power in
11、 small-angle neutron scattering.“It is the purpose of this note to suggest a second mechanism for polarizing fast neutrons-the spin-orbit interaction arising form the motion of the neutron magnetic moment in the in the nuclear Coulomb field.”APS-DNP W.Haeberli,University of Wisconsin Chicago October
12、 29,2019Maci nt osh PI CTi mage f or mati s not suppor t edSpin-orbit coupling:APS-DNP W.Haeberli,University of Wisconsin Chicago October 29,2019Coulomb-nuclear interference(“CNI”)Phil.Mag.1,175(1956)1010%sP U(n,n)U100 MeVFNAL E704 200 GeV/cPhys.Rev.D48,3026(1993)AN vs momentum transferPolarized pro
13、tons from Hyperon decay(low rate)CNI Analyzing Power in High-Energy pp Scattering E950BNLp=21.7 GeV/cPhys.Rev.Lett.89(2019)with hadronicspin-flipno hadronicspin-flipmomentum transfer(GeV/c)2CNI Analyzing Power p-Carbon Scatteringcalibration only at 22 GeV/csmall ANScale uncertainty 30%Unknown energy
14、 dependenceBut large count ratesneed for accurate absolute AN measurementMa c i n t o s h P I CTi ma g e f o r ma ti s n o t s u p p o r t e dMacintosh PICTimage formatis not supportedBeam Polarization Calibration Measure asymmetry e etgt when unpolarized beam is scattered from polarized target of K
15、NOWN polarization Pt -measures A Measure asymmetry e ebeam when polarized beam is scattered from unpolarized targetElastic scattering of IDENTICAL particles(pp):beam analyzing power=target analyzing power(Change in reference frame)Ma c i n t o s h P I C Ti ma g e f o r ma ti s n o t s u p p o r t e
16、dMaci nt osh PI CTi mage f or mati s not suppor t edAPS-DNP W.Haeberli,University of Wisconsin Chicago October 29,2019Both experiments done simultaneouslyMaci ntosh PI CTi mage formati s not supported+10-1+1/2 -1/2-1/2 +1/2mIPM acintosh PIC Tim age form atis not supportedThe Polarized Target-Princip
17、lerHH2aacceptance angle a a.and Practice Cooled dissociator nozzle to reduce v and v-spread.recombination:dissociation depends on gas flow and nozzle temp Beam attenuation:rest gas and intrabeam scattering Magnet design(taper,lengths,z-position)needs:velocity distribution,dissociator H output vs gas
18、 flow,nozzle T beam forming geometry differential pumpingOPTIMIZATION:COMPUTER MODELLING rare-earth perm.magnets,pole tip 1.5T,max d d|B|/d dr=6T/cm)overall design:Tom Wise,UWrHH2a24 sectors separatingmagnets with 1.5 T field at the pole tips.APS-DNP W.Haeberli,University of Wisconsin Chicago Octobe
19、r 29,2019H-jet sextupole separation magnet system.0 0.5m 1m 1.5m p-beamseparationmagnets(sextupoles)H2 dissociatorPolarimeterfocusingmagnets(sextupoles)RF transitionsholding fieldmagnet 1.2 kGrecoil ChamberSilicon Det.(1),(2)Pz+:(1),(4)(transition(2)(4)Pz-:(2),(3)(tranistion(1)(3)Hyperfine state(1),
20、(2),(3),(4)The Polarized H-jet at RHIC Beam intensity:(1.20.2)1017H/s Nuclear polarization of H-atomsEfficiency of RF transitions:(99.70.2)%ideal proton polarization for B=1.2kG:P=0.960 plus 3%dilution from H2 P=0.924 2%bunch-field depolarization 0.1%APS-DNP W.Haeberli,University of Wisconsin Chicag
21、o October 29,2019Scattering Chamber(top view)H-jet profileAPS-DNP W.Haeberli,University of Wisconsin Chicago October 29,2019Target thickness:(1.3 0.2)x1012 H/cm280 cmP RECOILH-JETRecoil detectors(blue beam):6 detectors 70 x64 mm 16 strips(5 mrad each)Measure Energy:17MeV resolution 50 keV TOF:1680 n
22、s resolution 2 ns Angle:10100 mrad(89.5-84O)resolution 5 mradBH jetRecoil DetectorsAPS-DNP W.Haeberli,University of Wisconsin Chicago October 29,2019RHIC beamTime of flight CNI peak AN 1 E 2 MeVRecoil protons elastic pp0 1 2 3 4 5 MeVRecoil energy vs.time-of-flight0a sourcecalibrationStrip#116TR MeV
23、241AmD DTOF +/-8 nsTOF vs TR Si detector of first 8 channelsTRTOFanalysisRecoil energy strip by strip241AmIdentifying recoil protons vs recoil angle(=strip#)pp elastic 100 GeV/c FNAL E704 200 GeV/cno hadronic spin-flipdata to analyzepp Analyzing Power 100GeV/cAN vs.momentum transferPolarization of 1
24、00 GeV Beam study systematic errors and improve statistics for absolute calibration accuracy 5%analyze wider t-range to study pp interaction bunch field depolarization with 110 bunches improved measurement of H2 contamination of H-beam measure beam polarization at injection measure blue and yellow b
25、eam polarization Plans:Maci ntosh PI CTi mage formati s not supported106 pp eventsWisconsin:,T.Wise,M.Chapman,W.H.BNL:A.Bravar,G.Bunce,R.Gill,Z.Li,A.Khodinov,A.Kponou,Y.Makdisi,W.Meng,A.Nass,S.Rescia,A.ZelenskiKyoto:H.Okada,N.SaitoITEP-Moscow:I.Alekseev,D.SviridaIUCF:E.StephensonRIKEN-BNL:O.Jinnouch
26、i,Rikkyo U:K.KuritaANL:H.Spinka H-Jet collaborators:1.26 kmno hadronic spin-flip pp elastic 100 GeV/c FNAL E704 200 GeV/cdata to analyzeRecoil angle 89.5oRecoil energy 0.53 MeV 5.3MeVpp Analyzing Power 100GeV/cAN vs.momentum transferPlans Plans:improve statistics,study systematic errors for absolute
27、 calibration accuracy 5%analyze wider t-range to study pp interaction bunch field depolarization with 110 bunches improved measurement of H2 contamination of H-beam measure beam polarization at injection measure blue and yellow beam polarization APS-DNP W.Haeberli,University of Wisconsin Chicago Oct
28、ober 29,2019RHIC pp accelerator complexBRAHMS&PP2PP(p)STAR(p)PHENIX(p)AGSLINACBOOSTERPol.Proton Source500 mA,300 msSpin RotatorsPartial Siberian SnakeSiberian Snakes200 MeV PolarimeterAGS Internal PolarimeterRf Dipoles p-C PolarimetersAbsolute Polarimeter(H jet)0.7 1011 pol.protons/bunch56 bunchesAG
29、S pC PolarimetersStrong AGS Snake+-+-+-+-+L=4x1030s-1cm-2,Pbeam 40%Ma c i nt os h PI CTi ma ge f or ma ti s not s uppor t e dRHIC experiments will measure DGBUT HOW DOES ONE KNOW Pbeam?Colliding polarized protons couple directly to gluons(rather than via charge)-measure parton asymmetries.Measure po
30、larization of gluons through g,jets,p pis,heavy quarks.G.Bunce DUBNA-SPIN-03 HERMES internal targetPure polarised gas targets:H,D,target polarisation:pT 85%Luminosity:6*1033 cm-2 s-1(D 50 mA)spin reversal every 120 secFactor 100 gain fromuse of storage cellThe Data(a sample)number of events(a.u.)Rec
31、onstructedMissing Mass2FWHM 0.1 GeV2SimulationMM2FWHM 0.1 GeV2Inelastic ThresholdGeV2 Du+Dd+Ds 0,20 0,04 .QCD analysis of Q2 dependence:K.Rith DIS 2019DIS of polarized HE leptons frompolarized nucleons atSLAC,CERN,HERA:The(old)proton spin puzzle:Only 20%of proton spin isaccounted for by spins ofquar
32、ks and antiquarksTwo experimental methods:thick solid polarized target+low intensity e or m beam Thin polarized gas target+high intensity beamWhat accounts for the spin of the nucleon?APS-DNP W.Haeberli,University of Wisconsin Chicago October 29,2019preliminaryNon-hadron spin flip(Re r5=-0.02)(Re r5
33、=+0.02)Comparison with some models(Not Fitting)Demonstrated feasibility of accurate beam polarization calibration at high energy calibration of p-C polarimeter measurement of pp AN(8 angles,10%)H-jet does not interfere with p-beam life time 3%measurement requires 200 hrs with improved beam intensity
34、 method covers entire energy range of RHIC one important step towards a precise determination of DG CONCLUSIONS:lSolenoidal fieldlAxial FieldnSTARMa c i nt os h PI CTi ma ge f or ma ti s not s uppor t e dRHIC experiments will measure DGBUT HOW DOES ONE KNOW Pbeam?nPHENIXPolarization of 100 GeV BeamM
35、aci nt osh PI CTi mage f ormati s not support ed Plans:analyze wider t-range to study pp intercaction improve statistics bunch field depolarization with 110 bunches improved measurement of H2 contamination of H-beam measure beam polarization at injection measure blue and yellow beam polarization Eve
36、ntual goal ofcalibration:3%APS-DNP W.Haeberli,University of Wisconsin Chicago October 29,2019Strip#116TR MeV241AmD DTOF +/-8 nsMacintosh PICTimage formatis not supportedTOF vs TR Si detector of 16channels#1#16#4TRTOFanalysisH+10-1+1/2 -1/2-1/2 +1/2mIPM acintosh PIC Tim age form atis not supportedThe
37、 Polarized Target-PrincipleH2raacceptance angle a arHH2HThe Polarized Target-PrincipleH2raacceptance angle a arHH2 Sextupoles:rare-earth permanent magnets(gradient up to 6 T/cm)Magnet geometry:2 magnet groups reduce chromatic aberrations magnet gaps reduce gas attenuation taper increases acceptance
38、RF transitions of high efficiency very uniform guide field to avoid bunch field depolarization Field shaping for adiabatic transport responsible for design:T.Wise UWH-Jet Design FeaturesAPS-DNP W.Haeberli,University of Wisconsin Chicago October 29,2019permanent magnet sextupole pole tip field 1.5T24
39、 sectors separatingmagnets with 1.5 T field at the pole tips.APS-DNP W.Haeberli,University of Wisconsin Chicago October 29,2019H-jet sextupole separation magnet system.0 0.5m 1m 1.5m p-beam+10-1+1/2 -1/2-1/2 +1/2mIPM acintosh PIC Tim age form atis not supportedThe Polarized Target-PrinciplerHH2aacce
40、ptance angle a arHH2H+10-1+1/2 -1/2-1/2 +1/2mIPM acintosh PIC Tim age form atis not supportedThe Polarized Target-PrincipleH2raacceptance angle a aacceptance angle a a Sextupoles:rare-earth permanent magnets(gradient up to 6 T/cm)Magnet geometry:2 magnet groups reduce chromatic aberrations magnet ga
41、ps reduce gas attenuation taper increases acceptance RF transitions of high efficiency very uniform guide field to avoid bunch field depolarization Field shaping for adiabatic transport responsible for design:T.Wise UWH-Jet Design FeaturesAPS-DNP W.Haeberli,University of Wisconsin Chicago October 29,2019permanent magnet sextupole pole tip field 1.5T谢谢你的阅读v知识就是财富v丰富你的人生
