COLLINEAR SSFS WITH DEUTERIUM Sebastian Kuhn, Old Dominion - - PowerPoint PPT Presentation

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COLLINEAR SSFS WITH DEUTERIUM Sebastian Kuhn, Old Dominion - - PowerPoint PPT Presentation

Apr 16, 2023 208 likes •336 views

COLLINEAR SSFS WITH DEUTERIUM Sebastian Kuhn, Old Dominion University How much can we learn about d ( x 1) s at moderately large x G at moderately large x if we double the approved running time on deuterium?

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SLIDE 1

COLLINEAR SSFS WITH DEUTERIUM

How much can we learn about Ø ΔΣ ΔΣ Ø Δd (x →1) Ø Δs at moderately large x Ø ΔG at moderately large x if we double the approved running time on deuterium? (Hint: answer will take a while!) Tools: inclusive double spin asymmetries, pT-integrated π and K double spin asymmetries (longitudinally polar. D)

Sebastian Kuhn, Old Dominion University

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SLIDE 2

PRESENT SITUATION

DSSV: PRL 101, 072001 (2008)

Asymmetries in pp at RHIC

g1 “h.H”

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SLIDE 3

WHAT’S MISSING?

Ø Δu/u and Δd/d at high x still poorly constrained Ø What is happening with the strange sea polarization? >0? =0? <0? Zero crossing? (Tension DIS – SIDIS) Ø Is the sea polarization isospin-symmetric? (note: we already know ) Ø Gluon helicity distribution at large x and a small x? What is the integral ΔG? Ø What happens at really small x << 0.01? Ø … and where is the rest of the nucleon spin? (only 30-40% explained by quark helicities) Orbital angular momentum of quarks, total angular momentum carried by gluons…

u ≠ d

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SLIDE 4

12 GEV CAPABILITIES – HALL B

CLAS12 Polarized Targets

  • VERY large acceptance
  • Full PID (K and π)

(K ID requires major new funds for RICH)

  • Moderately high

luminosity (1035 cm-2s-1) (matched to NH3, ND3)

  • Standard DNP longitudinal

NH3, ND3 targets

(funded by NSF MRI, under construction)

  • HD-Ice target

(suitability for e- beam remains to be demonstrated)

Future longitudinally polarized target for CLAS12 (11 GeV program at Jefferson Lab)

  • Horizontal 4He evaporation cryostat
  • 5 T B-field provided by central detector
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SLIDE 5

APPROVED CLAS12 EXP . E12-06-109 (A)

E12-06-109 – Request:

  • Ebeam = 11 GeV, Pb=85%
  • L ≈ 2 x 1035 /cm2/s
  • 25 days on p, 45 days on d, 10 days on

auxiliary targets Also: E12-09-007(b) “Study of partonic distributions using SIDIS K production” Contact: Kawtar Hafidi (A-)

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SLIDE 6

Kinematic Coverage (DIS)

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SLIDE 7

PREDICTED DATA FROM CLAS12

Proton Deuteron

W > 2; Q2 > 1

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SLIDE 8

INCLUSIVE + TAGGED SSF – HALL B

SIDIS A1

h+ h-

Improved PDFs from NLO analyses Better determination

  • f Higher Twist vs. x

Improved coverage to evaluate moments

Greater x-coverage for Γ1 Inclusive A1

p d

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SLIDE 9
  • 1.0
  • 0.8
  • 0.6
  • 0.4
  • 0.2

0.0 0.2 0.4 0.6 0.8 1.0 0.2 0.4 0.6 0.8 1 Delta_d/d x

CLAS12 EG1b HallA

DELTA-D / D

  • 1.0
  • 0.8
  • 0.6
  • 0.4
  • 0.2

0.0 0.2 0.4 0.6 0.8 1.0 0.2 0.4 0.6 0.8 1 Delta_d/d x

CLAS12 EG1b HallA

100 days on ND3 50 days on ND3

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SLIDE 10

JAM COLLABORATION

+ iterative MC method

Nobuo Sato

  • W. Melnitchouk, S. E. Kuhn, J. J. Ethier, A. Accardi
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SLIDE 11
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SLIDE 12

FUTURE W/ JAM

Add SIDIS and pp Will evaluate impact of 11 GeV data with 50 and with 100 days

  • f deuterium in CLAS12

→ expect significant improvement of ΔG, Δs, Δd and ΔΣ ΔΣ

  • hopefully first results by end of March, to include in

separate mini-proposal for run group (C++?)

10−1 x −0.2 −0.1 0.0 0.1 0.2 0.3 0.4 0.5

(b) AK−

1,d

u d s ub db sb DSSV+DSS total HERMES

Produc3on of Kaons in SIDIS

  • What happens when we remove the strange PDF in the theory

calcula0on?

10−1 x −0.2 −0.1 0.0 0.1 0.2 0.3 0.4 0.5

(b) AK−

1,d

u d s ub db sb DSSV+DSS total HERMES

χ2

dof = 0.38

χ2

dof = 0.51

∆s → 0