PREX and CREX 208. Neutron Skin. Robert Michaels Jefferson Lab NuSYM e. Electroweak Asymmetry in Elastic Electron-Nucleus Scattering

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1 PREX an CREX 08 Pb 48 Ca Robet Michaels Jeffeson Lab NuSYM018 e + 0 e Z A PV R R L L ~ 10 4 Q ~ 10 6 C. J. Hoowitz Electoweak Asymmety in Elastic Electon-Nucleus Scatteing Neuton Skin R n R p n p 1/15

2 PREX Kent Paschke * UVa Kishna Kuma Stony Book Univesity Robet Michaels Jeffeson Lab Seamus Rioan* Robet Michaels Kent Paschke Paul Soue CREX Agonne National Lab Jeffeson Lab UVa Syacuse Univeisty Paul Soue Syacuse Univeisty Dustin McNulty Iaho State Univesity Guio Ucioli INFN Rome Juliette Mammei Manitoba Univesity * contact pesons Silviu Covig Jeffeson Lab Neuton Skin of 08 Pb an 48 Ca Jan 18, 017 p /

3 Neuton fom facto A G F Q 1 4sin W F F N P Q Q Hall A Choice of Nuclea Tagets Fist excite state fa fom elastic Neuton excess Doubly-magic Stable High Resolution 10-4 Spectometes 08 Pb 48 Ca Robet Michaels, NuSYM018 Hall A

4 ˆ 5 A V V 4sin 1 Q F Q F Q G A P N W F L R L R neuton weak chage >> poton weak chage is small, best obseve by paity violation / / / 3 Z V 4sin 1 N Z G A N P W F Q F P Mott q j Q F P P q j Q F N N Electon - Nucleus Potential electomagnetic axial Neuton fom facto Paity Violating Asymmety A 1 4sin 1 W Poton fom facto 0 Pb is spin 0 08 Using Paity Violation p4 / Robet Michaels, NuSYM018

5 Neuton Skin vs Mass Numbe A R N R P fm C-REX Appove poposal PREX-I publishe PREX-II Appove poposal Theoy : P. Ring et al. NPA 64, A Robet Michaels, NuSYM018 p5 /

6 Weak Inteaction: Sees the Neutons T.W. Donnelly, J. Dubach, I. Sick Nucl. Phys. A 503, 589, 1989 poton neuton Electic chage 1 0 Weak chage Measue Asymmety Coect fo Coulomb Distotions APPLICATIONS C. J. Hoowitz Nuclea Theoy Symmety Enegy Weak Density at one Q Small Coections fo n s G E G E MEC suface thickness Heavy Neuton Atomic Paity Violation Skin Ions Stas R N - R P

7 Ways to Fin Neuton Distibution an Symmety Enegy Poton-Nucleus Elastic Pion, alpha, Scatteing Heavy ion collisions Rae Isotopes ipline Pion Photopouction Electic Dipole Polaizabilities Magnetic scatteing Involve stong pobes Electomagnetic pobes PREX / CREX A PV Neutino-nucleus coheent Weak inteaction Theoy MFT fit mostly by ata othe than neuton ensities Robet Michaels, NuSYM018 p7 /

8 Neuton skin measue by APV Robust coelation between 08 Pb APV an the neuton skin ove existing nuclea stuctue moels X. Roca-Maza et al. PRL Apv in PVES povies a clean pobe of the neuton istibution PREX: APV to 3% fom 08 Pb CREX: APV to.5% fom 48 Ca -> n to 0.06 fm accuacy -> n to 0.0 fm accuacy Robet Michaels, NuSYM018 Neuton Skin of 08 Pb an 48 Ca Jan 18, 017 p8 / 8

9 Ab Initio exact micoscopic calculations of R skin fo 48 Ca have ecently been publishe. Can be compae to Density Functional Theoy the e an blue points an Dispesive Optical Moel DOM W. Dickhoff, et al. PRL 119, Fattoyev, Piekaewicz PRC 86, G. Hagen, et al. Natue 1,

10 Paity Expeiment Metho integating moe Flux Integation Technique: C-REX : 140 MHz PREX: 500 MHz Example : HAPPEX Robet Michaels, NuSYM018

11 Paity Violating Asymmety A PV R R L L ~ 10 4 Q ~ 10 6 e Pb e Z 08 Pb A PV fom intefeence Applications of A PV at Jeffeson Lab Nucleon Stuctue Stangeness s s in poton HAPPEX, G0 expts Test of Stana Moel of Electoweak e e MOLLER o e q PVDIS elastic e p at low Q QWEAK sin Nuclea Stuctue neuton ensity : PREX W & CREX Robet Michaels, NuSYM018 p 11 /

12 Hall A High Resolution Spectometes Resolve Elastic Scatteing Disciminate Excite States Elastic Inelastic etecto PREX 1.0 GeV 5 0 CREX.0 GeV 5 0 taget Qua Dipole Quatz etectos Quas scintillato Dift chambes Robet Michaels, NuSYM018 p 1 /

13 HRS + septum Pb taget PREX-I Results PRL A Physics Asymmety ppm stat syst Hall A JLAB Pol. Souce CEBAF Statistics limite 9% Systematic eo goal achieve! % Septum Magnet HRS Pb taget /

14 Units: micons Paity Quality Beam : Unique Stength of JLab Helicity Coelate Position Diffeences X R X L fo helicity L, R Plotte below Points: Not sign-coecte nm iffs. with pol. souce setup & feeback Sign flips povie futhe suppession : Aveage with signs = what expeiment feels achieve < 5 nm A aw = A et - A Q + E + i x i Sign flips using ½ wave plate & Wien filte This BPM, Aveage =.4 PREX ata Measue sepaately 3.1 nm Robet Michaels, NuSYM018 Slug # ~ 1 ay 14 /

15 PREX-I Asymmety P e x A A ppm Slug # ~ 1 ay Robet Michaels, NuSYM /

16 Asymmety leas to R N PREX-I has establishe a neuton skin at ~95 % CL Neuton Skin = R N - R P = fm PRL Robet Michaels, NuSYM018

17 PREX-II an C-REX Status Impove the shieling an vacuum seals Expeiments appove PREX-II A ating 35 ays C-REX A- ating 45 ays Systematic Eo Goals fo PREX-II emonstate by PREX-I Scheule to un in 019 spectometes tagets 08 Pb 48 Ca Robet Michaels, NuSYM018 p 17 /

18 New PREX / CREX Scatteing Chambe One cyo-coole pouction taget lae an one calibation-taget lae. Impove ha vacuum seals Run PREX an CREX with one installation Small chambe allows efficient shieling Beam Septum magnet Collimato Box Scatteing Chambe Robet Michaels, NuSYM018 Beam Neuton Skin of 08 Pb an 48 Ca Jan 18, / 11 8

19 Detectos Developments GEMs PMT Cheenkov aiation fom electons tavesing thin quatz. Quatz etectos Electons in HRS Quatz etecto e - Simulation an ata benchmake quatz popeties Also, GEMs fo high-ate tacking Teste at Iaho an Stony Book Beam tests at Mainz RMS/Mean ~ 19% Neuton Skin of 08 Pb an 48 Ca Jan 18, 017

20 PREX / CREX PREX-I E=1.1 GeV, 5 o A=0.6 ppm Chage Nomalization 0.% Beam Asymmeties 1.1% Detecto Non-lineaity 1.% Tansvese Asym 0.% Polaization 1.3% Taget Backing 0.4% Inelastic Contibution <0.1% Effective Q 0.5% Total Systematic.1% Total Statistical 9% Achieve, publishe statistics limite esult, systematics well une contol PREX-: 3% stat, 0.06 fm CREX:.4% stat, 0.0fm PREX-II E=1.1 GeV, 5 o A=0.6 ppm 70 μa, 5+10 ays Chage Nomalization 0.1% Beam Asymmeties* 1.1% Detecto Non-lineaity* 1.0% Tansvese Asym 0.% Polaization* 1.1% Taget Backing 0.4% Inelastic Contibution <0.1% Effective Q 0.4% Total Systematic % Total Statistical 3% *Expeience suggests that leaing systematic eos can be impove beyon poposal Expeiments CREX E=1.9 GeV, 5 o A =.3 ppm 150 μa, ays Chage Nomalization 0.1% Beam Asymmeties 0.3% Detecto Non-lineaity 0.3% Tansvese Asym 0.1% Polaization 0.8% Taget Contamination 0.% Inelastic Contibution 0.% Effective Q 0.8% Total Systematic 1.% Total Statistical.4% Neuton Skin of 08 Pb an 48 Ca Jan 18, 017 0

21 Futue Weak Chage Scan? Electon Scatteing lowe Q at Mainz highe Q at JLab Focusing Solenoi M. Thiel, D. Becke, P. Soue Z. Lin, S. Ban, C.J. Hoowitz J. Phys. G ; PRC C9, p 0 / 1

22 PREX, C-REX : Summay Funamental Nuclea Physics with many applications PREX-I : 9% stat. eo in Asymmety Goals: PREX-II 3 % 0.06 fm, C-REX.4% 0.0 fm Systematic Eo Goals Achieve Appaatus is une constuction. Scheule to un in 019 Robet Michaels, NuSYM018