the electron nucleon collider a possible future upgrade to fair f. maas helmholtz institute mainz...
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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
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