The Electron Nucleon Collider a possible future upgrade to FAIR F. Maas Helmholtz Institute Mainz NuPECC town meeting May 31 - June 2, 2010 CSIC, Madrid.

The Electron Nucleon Collider

a possible future upgrade to FAIR

F. MaasHelmholtz Institute Mainz

NuPECC town meeting May 31 - June 2, 2010

CSIC, Madrid

Scientific Goals

- Challenge: understand the structure of hadrons and their excited states from first principles- Predict hadronic properties and processes with good and controlled precision.- Ideal probe: CC neutrino and anti-neutrino interactions- More realistic: interaction of polarized charged lepton beams with polarized p and d- dominated by γ exchange at Q2 ≪ M2

Z,W , coupling to quark charges only- doubly polarized: projecting helicities

- Spin flavour structure of quarks f, g (longitudinal), h(transverse) and polarized Gluons- Effects of finite transverse size, correlation of b and x, orbital angular momentum, GPDs- Effects of transverse momentum k⊥of quarks, gauge links

High Energy Lepton Scattering

inclusive Scattering (lepton only), exclusive Scattering (complete final

state: lepton, photon, proton),semi-inclusive scattering

High luminosity lepton-nucleon collider- The electromagnetic probe: precision of the EW interaction, but needs high luminosity- Lepton scattering on hadron targets in new regimes yielded new insights, e.g. DIS, EMC effect, Glue- new regimes: Exclusive reactions, Semiinclusive Deep Inelastic Scattering- High Ecm yields a large range of x, Q2

x range: valence, sea quarks, glue Q2 range: evolution equations of QCD- High polarization of lepton, nucleon achievable

dilution in fixed target experiments- Collider geometry allows complete reconstruction of final state

30 Years of Deep Inelastic Scattering

- 1970 - 2000 Analysis of DIS in terms of pQCD

Energy/Luminosity Landscape

ENC

Electron Nucleon Collider:

- high energy- high luminosity- polarisation

LHeC

Unpolarised Parton Distributions

ValenceSea

Understanding Origin of Nucleon Spin

Generalized Parton Distributions (GPDs):3D picture of the nucleon, Angular Momentum Sum Rule

Transverse Momentum Dependent Parton Distributions

QCD prediction

:transversely polarised

target in PANDA;

PAX

Study of Beam Dynamics: Beam equilibria and luminosities

Study of Spin Dynamics: Spin resonances in SIS18 and HESR

Andreas Jankowiak, Institut für Kernphysik, Johannes Gutenberg – University Mainz

idea: ENC@FAIR

P

e-

pol.

e- -i

nj.

L > 1032 1/cm2s

s1/2 > 10GeV(3.3GeV e- ↔ 15GeV p)

polarised e- ( > 80%)↔

polarised p / d ( > 80%)(transversal + longitudinal)

using the PANDA detector

Common effort ofGerman Universities

(Bonn, Mainz, Dortmund) plus collaboration with

Research CentresFZJ, DESY, GSI, ...

HESRpRing

eRing

PANDA8M

V e

Cool

Andreas Jankowiak, Institut für Kernphysik, Johannes Gutenberg – University Mainz

The eRing

24to dipole,4.3to quadrupole

both nc

eRing dipole:ca. 0.4m×0.25m and1.6to for 4m length

eRing inside the HESR tunnel !

In addition:

- cavities- spin-manipulation- injection/extraction- feedback- ...

Andreas Jankowiak, Institut für Kernphysik, Johannes Gutenberg – University Mainz

HESR / 15GeV p eRing / 3.3GeV

L [circumference, m] 576 577.126

R [bending radius, m] 30 25

εnorm / εgeo [mm mrad ] 2 / 0.13

βIP [m] 0.1

rIP [mm] / θIP [mrad] 0.111 / 1.12

l [bunch length, m] 0.1 < 0.1

n [particle / bunch 1010] 3.6 23

Ib [bunch current, mA] 3.0 19.1

h [bunches / ring] 200 200

I [total current, A] 0.60 3.82

PSR [sr-Power, kW] / [kW/m] 1590 / 10

fcoll [collision freq., MHz] 103.892

λcoll [bunch distance, m] 2.88 2.8857

ΔQsc 0.1

ξ [beam beam parameter] 0.014 0.01

Luminosität [1/(cm2s)](inc. 80% hour glass red.) 1 - 4 · 1032

P [polarisation, %] 80% 80%

needs 8.2MV eCool

IR + detector design

bunching process

B-factory designx 2

x 2

possible under collision?polarisation preservation?

polarisation?

27 G

eV

com

pass

herm

es JLab (upgraded)

JLab@6GeV

Q2

EIC

HERA

ENCENC

JLab12

EIC

ENC

Q2

ENC

∫L dt (fb-1)

EC

M (G

eV

)

0

20

40

60

80

Science reach as a function of ECM and integrated luminosity

100

120

1 10 100

gluon saturation

sin2θW

DIS

n

ucl

eon

str

uct

ure

excl

usi

ve,

ele

ctro

weak

pro

cess

es

xmin ~ 10-2

xmin ~ 10-3

xmin ~ 10-4

50 fb-1

quark

s, g

luon

s in

nu

clei

4 X 250 MeRHIC

10 X 250 EIC

3 X 15 ENC

ENC@PANDA@FAIR:- A polarized Electron-Nucleon-Collider

L ≈ 4 1032/cm2/ss ≈ 200 GeV2

- add 3 GeV electron beam in HESR tunnel to 15 GeV protons- polarised proton source- needs 8 MeV electron cooling- highly polarised electron and nucleon beam- factor of 100 higher FOM in doubly polarised channels

- (slightly) modified PANDA detector with shifted IR- first step in IR-design, polarisation

- great potential for exploring the structure of the nucleon

Summary