The J-PARC Facility and Ideas for TMD Measurements

The J-PARC Facility and Ideas for TMD Measurements

ECT* Workshop

June 15, 2007

Yuji Goto (RIKEN/RBRC)

June 15, 2007 ECT* Workshop 2

J-PARC at Tokai

TOKYO

KEK

JAERI

NARITA

KAMIOKA

Tsukuba

Tokai1 hour

295 km JAEA


J-PARC facility

Nuclear Transmutation

J-PARC = Japan Proton Accelerator Research Complex

3 GeV Synchrotron(25 Hz, 1MW)

Hadron Beam FacilityMaterials and Life Science

Experimental Facility

Neutrino to Kamiokande

50 GeV Synchrotron(0.75 MW)

500 m

Linac(330m)

Joint Project between KEK and JAEA


J-PARC facility– The budget for about 2/3 of the entire project has

been approved by the Japanese government from JFY2001 as phase 1

– Phase 1 consists of major accelerator components and a part of experimental facilities


J-PARC parameters• 50 GeV beam

– repetition 3.4 ~ 5 (or 6) sec– flat top width 0.7 ~ 2 (or 3) sec– linac energy 400 MeV– 3.31014 ppp, 15 A– beam power 750 kW

• 30 GeV beam (phase-1)– linac energy 180 MeV– 21014 ppp, 9 A– beam power 270 kW


J-PARC schedule

• June, 2007: Completion of civil construction of the Hadron Hall• December, 2007: Start of dry run of the main-ring synchrotron• May, 2008: Start of beam commissioning of the main-ring synchrotron• December 2008: Acceleration to 30 GeV and the first beam to the

Hadron Hall

first beam for the nuclear-particle experiments inJFY2008 first beam for theneutrino experimentsin JFY2009


ＭＬＳＦ

RCS

ＬＩ

ＮＡ

Ｃ

50GeV-PS

HdBird’s eye photo in Nov. 2006


Hadron experimental hall (phase 1)

BeamDump

A-Line

Experimental Area

Test Beam

(on the guide rail

for Phase 2)

beamlines for secondary beam experiments at the beginning of the phase1

area for primary beam experiments


Dimuon experiment at J-PARC• Proposal and collaborators


Dimuon experiment at J-PARC• Drell-Yan

– the simplest process in hadron-hadron reactions

• no final-state effect• no polarized Drell-Yan experiment done yet

– rich programs• unpolarized and polarized program• flavor asymmetry of the sea-quark distribution• orbital angular momentum in the nucleon• transversity, etc.

DIS Drell-Yan


Dimuon experiment• Fermilab E866 experiment

– flavor asymmetry of the seq quark distribution

)(

)(1

2

1~

2 2

2

xu

xdpp

pd

012.0118.0

)]()([

011.00803.0

)]()([

CTEQ5Mwith

1

0

35.0

015.0

xuxddx

xuxddx


Dimuon experiment• Fermilab E906 experiment

– similar experiment of E866 at lower energy 120 GeV with Tevatron main injector to cover higher-x region

– construction 2007 – 2008 (or 2009) – not yet started– beam time 2009 – 2010 (or 2010 – 2011)

• apparatus– partially to be used at J-PARC


Dimuon experiment at J-PARC• Possible layout of the hadron hall


Dimuon experiment at J-PARC• Unpolarized program

– proton beam on proton and deuterium target


Spin physics at J-PARC• Polarized Drell-Yan

– ALL measurement• flavor asymmetry of sea-quark polarization

chiral quark solitonmodel prediction

120-day run75% polarization for a 51011 protons/spillpolarized solid NH3 target, 75% hydrogen polarization and 0.15 dilution factor

GS-CGS-AGRSV


Spin physics at J-PARC G will be made clear by RHIC and pol-DIS

experiments soon…• Orbital angular momentum in the nucleon

– in hadron-hadron reaction, no direct connection between measurement and theory (yet)

– but, any partonic transverse motion and correlation should be related

• Sivers effect• higher-twist effect

– ALL measurement may also sensitive at high-xF…

• Feng Yuan’s calculation with Lz = 1 component… [Harut Avakian, Feng Yuan, et al. arXiv:0705.1553.]


Polarized Drell-Yan

• AN measurement– Ji, Qiu, Vogelsang, and Yuan

• PRD 73, 094017 (2006)

• sensitive to higher-twist effect at high qT ~ Q

• Sivers effect and higher-twist effect provide the same description of SSA on Drell-Yan at moderate qT: QCD << qT

<< Q• similar for SSA on semi-inclusive DIS: hep-ph/0604128

– Sivers function in Drell-Yan is expected to have a sign opposite to that in DIS


Polarized Drell-Yan

• AN measurement

Theory calculation by Ji, Qiu, Vogelsang and Yuan based on Sivers function fit of HERMES data (Vogelsang and Yuan: PRD 72, 054028 (2005))

1000 fb-1 (120-day run), 75% polarization, no dilution factor

4 < M+- < 5 GeVintegrated over qT


Polarized (and unpol.) Drell-Yan

• ATT measurement– transversity

• Boer-Mulders function by unpol. Drell-Yan– angular distribution of unpolarized Drell-Yan

– correlation between transverse quark spin and quark transverse momentum

)()( 21 xqxqATT

M

SkPkxh

M

SkPkxhN qqqq

)ˆ(),(

)ˆ(),()( 2

212

11

2 21 31 cos sin 2 cos sin cos 2

4 2

d

d


Polarized (and unpol.) Drell-Yan• Boer-Mulders function by unpol. Drell-Yan

– Lam-Tung relation• reflect the spin-1/2 nature of quarks

– violation of the Lam-Tung relation suggests non-perturbative origin

21

,

L.Y. Zhu,J.C. Peng, P. Reimer et al., hep-ex/0609005

With Boer-Mulders function h1┴:

ν(π-Wµ+µ-X)~valence h1┴(π)*valence

h1┴(p)

ν(pdµ+µ-X)~valence h1┴(p)*sea h1

┴(p)


Towards the goal• 30 GeV 50 GeV• unpolarized polarized target polarized beam

– polarized beam study by BNL & KEK groups– possible locations of partial snakes in MR

First 30% snake Second 30% snake


Physics at 30 GeV• J/

– gluon fusion or quark-pair annihilation– quark-pair annihilation dominant

• must be confirmed experimentally…• similar physics topics as Drell-Yan process

eq

J/Vqg

Vlg

q

q l

l

calculations by color-evaporation model


Physics at 30 GeV

• SSA measurement of open charm production– no single-spin transfer to the

final state– sensitive to initial state

effect: Sivers effect– collider energies: gluon-

fusion dominant• sensitive to gluon Sivers

effect– fixed-target energies: quark-

pair annihilation dominant• sinsitive to quark Sivers

effect

J-PARC: Elab = 50 GeV

M. Anselmino, U. D’Alesio, F. Murgia, et al.

RHIC: s = 200 GeV


Summary• J-PARC will start operation at 30 GeV for hadron-hall

users in JFY 2008• Possible high-momentum beam-line for primary beam

users in JFY 2011• Proposal of the dimuon experiment has been submitted

to the J-PARC PAC– deferred at the 1st J-PARC PAC, June 30 – July 2, 2006– to be resubmitted for the 3rd J-PARC PAC, July 6 – 7, 2007 to

get a stage-1 approval (scientific approval)• It has rich unpolarized and polarized programs

– flavor asymmetry of the sea-quark distribution– orbital angular momentum in the nucleon– transversity, etc.– J/ and charm physics with 30 GeV beam

• Your participation and collaboration, suggestions of measurements and theoretical calculations are very welcome

Backup Slides


J-PARC facility

Hadron ExperimentalFacility

Number of Users: about 600

(about 1/3 from Japan)

September, 2005


Hadron experimental hall (phase 1)

BeamDump

A-Line

Experimental Area

Test Beam

(on the guide rail

for Phase 2)

beamlines for secondary beam experiments at the beginning of the phase1

area for primary beam experiments


Dimuon experiment• Fermilab E866/NuSea

– closed geometry

Fermilab Elab = 800 GeV2×1012 protons / 20 sec


Experimental apparatus– based on the Fermilab spectrometer for 800 GeV, the length can be

reduced but the aperture has to be increased

– two vertically bending magnets with pT kick of 2.47 GeV/c and 0.5 GeV/c

– tracking is provided by three stations of MWPC and drift chambers– muon id and tracking are provided– 2x1012 50 GeV protons/spill

tapered copper beam dump andCu/C absorbers placed within the first magnet


Simulation studies• Expected Drell-Yan

counts for a two-month p+d run at 50 GeV– 2x1012 protons/spill– 50-cm long liquid

deuterium target– assume 50 percent

overall efficiency


D-meson– silicon detectors to identify second decay vertex– yield study

• 109 proton/sec beam• 10% target• 2×1033 cm-2sec-1

• × 1 week = 103 pb-1

• acceptance 0.05 – 0.3 to cover forward/mid-rapidity/backward

xF xF-1 -11 1

pT

1.5 GeV/c

pT > 1.5 GeV/cD0 yield 5.5×106 D0

for 103 pb-1


Polarized proton acceleration at J-PARC

– 50 GeV polarized protons for slow extracted beam primary fixed target experiments

– low intensity (~ 1012 ppp), low emittance (10 mm mrad) beams

Pol. H- Source

180/400 MeV Polarimeter

Rf Dipole

25-30% Helical Partial Siberian Snakes

pC CNI Polarimeter

Extracted BeamPolarimeter

Thomas Roser (BNL), et al.



• Intrinsic resonances in RCS

• emittance: 10 mm-mrad, 95%• repetition rate 25Hz• sinusoidal ramping• kinetic energy: 180MeV – 3GeV

• intrinsic resonance strength for a particle at an emittance of 10 mm-mrad

Full spin flip by a rf dipole

=2.33x10-5

=6.18x10-5

=7.63x10-5 =6.60x10-5Fast tune jump?

Mei Bai (BNL)



• Spin tracking in 50 GeV MR

Alfredo Luccio (BNL)

average of 12 particles on an ellipse of 4 mm-mrad


Polarized target• Michigan polarized target

– existing at KEK– target thickness ~3 cm (1%

target)– maybe operational with 1011

ppp (luminosity ~1034 cm-2s-1)


Physics at 30 GeV– cross section

• PYTHIA (6.228) study with PHENIX tune (<kT> = 1.5 GeV/c, Mc = 1.25 GeV/c2, K-factor = 3.5, Q2 = s)

• J-PARC: 3-4 order smaller cross section than that at RHIC– can be compensated by higher intensity/luminosity at J-PARC…

15101

0.1

15101

0.1consistent at fixed-targetregion, too

smaller yield (same resultas Laurenco’s study)

Wohri and Lourenco


Electron-pair experiment• E16 experiment at J-

PARC– search for nuclear-

matter effect in production

– covering backward production of electron-positron pairs


SSA measurements• Neutron

– large asymmetry found at RHIC– production mechanism of neutron

• one-pion exchange dominant – spin flip

• figures for study in DIS exps. (HERA), please replace virtual photon with proton to apply them for pp reaction

– asymmetry measurement• sensitive to interference between spin-flip term (one-pion

exchange) and non-spinflip term (other reggeon exchanges)


SSA measurements– neutron-tagged measurement

• measure AN of coincident particles at BBC at PHENIX• forward neutron, forward BBC, left-right

– (4.500.500.22)102 < 0• forward neutron, backward BBC, left-right

– (2.280.550.10)102 > 0

– asymmetry in the forward BBC has the same sign while backward particle has opposite sign AN

p

N*(*) n+X

YAN(X) < 0, AN(Y) > 0

p

p

n

X

pAN(X) > 0, AN(Y)??

initial-state effect - favored

final-state effect


SSA measurements– neutron-tagged measurement of Drell-Yan pair…

• Jen-Chieh Peng’s calculation expecting sensitivity to the meson cloud model, and measurement of pion structure

The J-PARC Facility and Ideas for TMD Measurements

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