Workshop on Hadron Structure at J-PARC, November 30 – December 2, 2005

laciloStrangeSpinmeasurements
baiat J-PARC
Dwith ν-N neutral current elastic scattering

Yoshiyuki Miyachi
Tokyo Institute of Technology

Recent activities
Presentations:- NP04, Aug. 2 - 4, 2004, Tokai“Determining strangeness quark spin in neutrino scattering at J-PARC (T.-A. Shibata)”- NP04 Neutrino session, Aug. 24 - 26, 2004, KEK“Strangeness Spin Contribution to the Nucleon Spin measured at J-PARC (N. Saito)”- NuFact05, June 21 - 26, 2005, Rome“Study for the Neutrino Coherent Pion Production Experiment (Y. Sakemi)”- NuInt05, September 26 – 29, 2005, Okayama“ Strangeness in Nucleon -- a summary from electron scattering experiments andprojection on neutrino scattering experiment (Y. Miyachi)”- PANIC05, Neutrino Planning Satellite meeting, October 30, 2005, Santa Fe“Strangeness Spin Measurement at J-PARC(Y. Miyachi)”R&D: Liquid scintillator test and detector simulation
Working group:
http://www.nucl.phys.titech.ac.jp/~sspin/

Mailing list for the working group:
nu-spin-jparc@nucl.phys.titech.ac.jp
if you are interested, just send an empty E-mail tonu-spin-jparc-help@nucl.phys.titech.ac.jp
December 1st, 2005, KEK

Workshop on Hadron Structure at J-PARC

Yoshiyuki Miyachi, Tokyo Tech

Contents• Strangeness in nucleon– Strangeness in nucleon– Proton spin problem• HERMES• Neutrino scattering– E734– Strange spin measurement at J-PARC• SummaryDecember 1st, 2005, KEK

Workshop on Hadron Structure at J-PARC

Yoshiyuki Miyachi, Tokyo TechStrangeness in nucleon
π-nucleon Σ-term:

=64±8 MeV

Phys. Rev. C69 (2004) 035207

strange scalar density
02 〈 p∣s s∣ p 〉y==1−〈 p∣u u∣ p〉〈 p∣d d∣ p〉
OZI rule breaking:y~0.5
Phys. Part. Nucl. 34 (2003) 94

puuduu,pduuss→ polarized strangeness?
J. R. Ellis et. al, Phys. Lett. B 353 (1995) 319, Nucl. Phys. A 673 (2000) 256
December 1st, 2005, KEK

Workshop on Hadron Structure at J-PARC

Yoshiyuki Miyachi, Tokyo TechStrange form factors- electric and magnetic form factors -Parity violating electron proton elastic scattering:e p  e '  p 'd  R −d  L
A PV =d  R d  L
2=ZZ

2e−G F Q  G E G E G M G M −1−4sin W   ' G M G A
4 2 2

G E   G M s

2d G E Q =0
dQ21 2,=−  s
6s

22G M Q =0=s
SAMPLE, HAPPEX, PVA4, G0, E91004

December 1st, 2005, KEK

Workshop on Hadron Structure at J-PARC

Yoshiyuki Miyachi, Tokyo Tech

Resent results fromParity Violating Electron Scattering
HAPPEX:
GsE +0.080GsM=0.030±0.025±0.006±0.012 (Q2=0.099GeV2) hep-ex/0506011
GsE =-0.038±0.042±0.010(with 4He)
(Q2=0.091GeV2) hep-ex/0506010

PVA4:
GsE +0.225GsM=0.039±0.034
GsE +0.106GsM=0.071±0.036

G0:(Q2=0.230GeV2) Phys. Rev. Lett. 93 (2004) 022002(Q2=0.108GeV2) Phys. Rev. Lett. 94 (2005) 152001

Phys. Rev. Lett. 95 (2005) 092001

GsE ≠ 0GsM ≠ 0details in the next talk by J. Arvieux→ GsA (=Δs) ?
December 1st, 2005, KEK

Workshop on Hadron Structure at J-PARC

Yoshiyuki Miyachi, Tokyo TechProton spin problem
Proton spin:=+1 1
1=  =  u d  s u  d  s 2 2
2
The most naive case: = u d  s=1
Naive parton model: q=q −qAssuming SU(3) flavor symmetry, taking axial current matrix = u d  s=a0
 u− d=a3
 u d−2  s=a8
Δq corresponds to axial form factor
Δq = GqA(Q2=0)
December 1st, 2005, KEK+

From weak decay:

a3=1.26,
a8 =0.58

if s = 0,  = a8 = 0.58

Workshop on Hadron Structure at J-PARC

Yoshiyuki Miyachi, Tokyo TechStrangeness spin inside proton- EMC results -Nucl. Phys. B328 (1989) 1, Phys. Lett. B206 (1988) 364

  ' X
 N

1
1
1
pdx
g

x=aaa8∫0 103912
36=0.126±0.01±0.015
1a 3=1.26, a 8=0.58

a 0~0.1
December 1st, 2005, KEK =0.1,  s s~−0.19sa 0= −3
G2with G0

Workshop on Hadron Structure at J-PARC

Yoshiyuki Miyachi, Tokyo TechSpin Physics is an important ingredient in particle physics.
Spin Papers by EMC have about the same number of citation as J/ψ, top,W, Z discoveries.
They are in Top5 among particle physics experiments using accelerators.
J.J. Aubert et al., Phys.Rev.Lett.33 1404-1406,1974
J.E. Augustin et al., Phys.Rev.Lett.33:1406-1408,1974
CDF, F. Abe et al., Phys.Rev.Lett.74:2626-2631,1995
EMC, J. Ashman et al., Phys.Lett.B206 364,1988
EMC, J. Ashman et al., Nucl.Phys.B328 1,1989
UA1, G. Arnison et al., Phys.Lett.B122:103-116,1983
UA1, G. Arnison et al., Phys.Lett.B126:398-410,1983

JψtWZ--- 1303--- 1223--- 1182--- 1180--- 1025--- 903--- 845SPIRES-HEP database
http://www.slac.stanford.edu/library/topcites/2003/alltime.shtml
December 1st, 2005, KEK

Workshop on Hadron Structure at J-PARC

Yoshiyuki Miyachi, Tokyo Tech

Flavor tagging in DIS
l  N  l ' h X
Structure Function
F i  x ,Q 2  , g i  x ,Q 2 d3   h22h2∝eqx,QDz,Q∑q2i qdx dz dQz=

Parton Distribution
2P⋅p h E h=P⋅q
2q  x , Q  ,  q x ,Q Flavor Tagging:
Hadron carries information onquark flavor

P= M , 0hq

2Fragmentation D  z , Q 

through fragmentation function

p h= E h , ph 

December 1st, 2005, KEK

Workshop on Hadron Structure at J-PARC

Yoshiyuki Miyachi, Tokyo TechHERMES at DESYHERMESgas targets:
unpol. (H, D, Ne, Kr, Xe)long. pol. (H, D)
trans. pol. (H)

DESY

HERA:
pol. electron/positron @ 27.5GeV
polarization about 55%
December 1st, 2005, KEK

Workshop on Hadron Structure at J-PARC

Yoshiyuki Miyachi, Tokyo TechStrangeness spin inside proton  e ' h Xe  N s  x =0- HERMES results -assumed

Phys. Rev D 71 (2005) 012003

assuming
Δq(x)=00.6

 q=∫0.023 dx  q x

Q 2=2.5 GeV 2

 u=0.601±0.039±0.049
 d =−.226±0.039±0.050
 u =−.002±0.036±0.023
 d =−.054±0.033±0.011
 s=0.028±0.033±0.009
December 1st, 2005, KEK

Iso-scalar method also gave Δs(x) = 0

Workshop on Hadron Structure at J-PARC

Yoshiyuki Miyachi, Tokyo TechStrangeness outside the coverage
http://durpdg.dur.ac.uk/hepdata/pdf3.html

CTEQ5:
1∫10 dx s  x ~2−5

0.6∫0.023 dx s  x ~0.15
22Q =2.5 GeV
0.6∫0.023 dx  s  x~0December 1st, 2005, KEK?

1

∫0 dx  s  x =?

Workshop on Hadron Structure at J-PARC

Yoshiyuki Miyachi, Tokyo TechOther impacts of ∆s measurements• Neutron EDM(J. Ellis and R. A. Flores PLB377 (1996) 83)– n-EDM predicted using q-EDM and Δq– d n ∝ mu  umd  dms  s• Dark Matter(J.Ellis and M. Karliner hep-ph/9601280)– Better determination of Dark-Matter reaction41∝  u   d  s  photino
99175
∝  u   d  s  pure U(1) gaugino
3636

December 1st, 2005, KEKWorkshop on Hadron Structure at J-PARC

Yoshiyuki Miyachi, Tokyo TechNeutrino-Nucleon Scattering
Measurement of strange spin inside nucleon
via Neutral Current Elastic Scatteringν-Nucleon (Quesi)-Elastic Scattering
2FdG Q22 A±BW ±CW =
22dQ 2  E A =B =C =4 E

1 2G 1 1 − F 21− F 22 1− 4  F 1 F 2
41− G 1  F 1 F 2 
421 mp 222G

F

F

112
16 Q 2[2Q
W=− 2mp mp]

Q2
=
4m 2p

NC-EL/CC-QE

Neutral Current[[[F 1,2=]

11 spn2pn−sin2 W [ F 1,2−F 1,2−sinFF−F 1,2]
W [ 1,21.2 ]22sGAGA
G 1= −  z 2
2December 1st, 2005, KEK]sA]
2G Q =0= s

Workshop on Hadron Structure at J-PARC

Yoshiyuki Miyachi, Tokyo TechNeutrino scattering and s- E734 results -• Neutral current cross section → strange axial form
factor• Liquid scintillator + Drift Tube 170 t• 0.5E19 POT for neutrino• 2.5E19POT for anti-neutrino

E734, Phys. Rev. D35 (1987) 785s2FromG(Q) to s•AsA2– G Q 0= s=−0.21±0.10• Further analysis: (Alberico et al.)RNC /CC =0.152±0.007±0.017
RNC /CC =0.218±0.012±0.023
RNC/=0.302±0.019±0.037-0.21 < s < 0December 1st, 2005, KEK

0.5Q 21.0 GeV2strong correlation with the axial mass MA

Workshop on Hadron Structure at J-PARC

Yoshiyuki Miyachi, Tokyo Tech

J-PARC ν-beam line
• Beam flux
– 1 GeV for “on-axis”– 0.8 GeV for “off-axis”• 1021 POT/year (130 days)– 30 times BNL-E734• anti-neutrino beam
– neutrino anti-neutrino
asymmetry measurement

December 1st, 2005, KEK

Workshop on Hadron Structure at J-PARC

Yoshiyuki Miyachi, Tokyo TechNeutrino elastic scattering cross section
E734, Phys. Rev. D35 (1987) 785

E734

FINeSSE

J-PARC?

E = 0.4

December 1st, 2005, KEK

0.6

0.8

1.0 GeVWorkshop on Hadron Structure at J-PARC

Yoshiyuki Miyachi, Tokyo TechFINeSSE
Fermilab Intense Neutrino Scattering Scintillator ExperimentLiq. Scintillator readout with WS fibers

Proposal:
LOI:

Fermilab
BNL

FINeSSE detector
Prototype→ S. Pate's talk

December 1st, 2005, KEK

Workshop on Hadron Structure at J-PARC

Yoshiyuki Miyachi, Tokyo TechExperiment at J-PARC• Off-axis beam line: peak energy < 1.0 GeV2
• Liquid scintillator with different H/C mixture– FINeSSE type detector– e.g Bicron BC510A (H/C=1.212) and BC-533 (H/C=1.96)• Pure Carbon can be extracted for nA Xsection– e.g. 5x5x5m3 ~ 125 t– Recoil proton with Tp = 40 MeV: Q2 ~ 0.1 GeV2
• High pressure hydrogen TPC dedicated for low Q2
measurements?

• 1E21 POT possible in one year (130 days)– 30 times BNL-E734
December 1st, 2005, KEK

Workshop on Hadron Structure at J-PARC

Yoshiyuki Miyachi, Tokyo Tech

Sensitivity at J-PARC– Similar Detection Efficiency to E734:• 7.6% for neutrino-N elastic, 5.4% for anti-neutrino-N elastic– However with lower Q2 cut-off : 0.1 GeV2
• Achievable with more uniform detector– Hydrogen TPC was not included in this estimation.

– 25 times more statistics but pure proton only 1/6• Factor 2 reduction in statistical error– Systematic control improvements to ~5%• E734 7.6% dominated by Beam Flux and Nuclear Effects• Possible to remove Nuclear Effects which could be larger in lower Q2region

 s=0.08
 s =0.03
December 1st, 2005, KEK

 E734
J-PARC

Workshop on Hadron Structure at J-PARC

Yoshiyuki Miyachi, Tokyo TechSummary• Strangeness in the nucleon– has been studied with various probes• π-N Σ-term, OZI violation, Deep Inelastic Scattering, ...

– Proton spin problem• Relates strange spin inside nucleon: positive? negative? zero?

• Neutrino scattering– Unique tool for studying strange spin inside nucleon• nucleon axial form factor measurement– Key points: nuclear effects, Q2 extrapolation to Q2=0– Measurement at J-PARC• δ(Δs) ~ 0.03 expected (E734: δ(Δs) ~ 0.08)
December 1st, 2005, KEK

Workshop on Hadron Structure at J-PARC

Yoshiyuki Miyachi, Tokyo Tech