LHeC に向けて
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LHeC にににに にににに ＫＥＫ 2008 に 1 に 12 に proto ns antiproto ns proto ns protons electrons ? 12/Jan/2008 1
description
antiprotons. protons. LHeC に向けて. protons. electrons?. protons. ＫＥＫ 徳宿克夫 2008 年 1 月 12 日. nuclei. proton. HERA: (27.5 GeV e vs 920GeV p) LHeC (70GeV e vs 7000GeV p). LHeC. 歴史. “ Deep Inelastic Electron-Nucleon Scattering at the LHC ” - PowerPoint PPT Presentation
Transcript of LHeC に向けて
LHeC に向けて
ＫＥＫ 徳宿克夫2008 年 1 月 12 日
protons
antiprotons
protons
protonselectrons?
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proton
nuclei
HERA: (27.5 GeV e vs 920GeV p)
LHeC(70GeV e vs 7000GeV p)
LHeC
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歴史• “Deep Inelastic Electron-Nucleon Scattering at the LHC” J.B. Dainton, M. Klein, P. Newman, E. Perez, F.
Willeke JINST 1 (2006) P10001• DIS2006 ( つくば） ： J. Dainton のトーク• 2006 Ａｄｖｉｓｏｒｙ Ｃｏｍｍｉｔｔｅｅ が組織• 2007 Ｓｔｅｅｒｉｎｇ Ｇｒｏｕｐ結成 10 月 26 日 初会合• 2007 年 11 月 30 日 Open ECFA ミーティングでの発表 （Ｍ．
Ｋｌｅｉｎ） ECFA, CERN のサポートが得られる。• ＷＧ結成に向けて、Ｃｏｎｖｅｎｏｒの人選中。 2008 年 9 月に
CERN 近辺でワークショップ。• 2009 年末に ＣＤＲ
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ep と pp が同時に実験できるオプション以外はない。 電子加速器を建設する機会は LHC アップグレードのときのみ
New physics, distancescales few . 10-20 m
High precisionpartons in LHC
plateauLow x parton
dynamicsHigh Density Matter
Large xpartons
Inclusive Kinematics for 70 GeV x 7 TeVInclusive Kinematics for 70 GeV x 7 TeV
s 1.4 V Te1.4 eV TW
710 at x 2 2 1 GeVQ
• High mass (Q2) frontier
• Q2 lever-arm at moderate x
• Low x (high W) frontier
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LHC 対生成LHeC もともとある クォークとレプトンから作れる
● たとえば、 leptoquark レプトンとクォークがあるなら、その両方の 性質をもった粒子もあっていいのでは？
Re + resonance
LHC で発見された後、 LHeC で狙いを定めて精密測定12/Jan/2008 5
対生成の断面積は、 QCD ： αs とマスで決まる。Eq だと断面積はその e-q-LQ 結合の強さによる。
Sensitivity は残念ながら、 LHC よりそう優れているわけではない。
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Asym
met
ry
LHeC: 10 fb-1 per charge
LHC: single prod. 100 fb-1
= 0.1
e,
q
+F = -1
F = +1
e+
e-
q or q ?_
q or q ?_
しかし、見つかったあとで、 LQ の性質を調べるのには LHeC は非常に有効
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New physics, distancescales few . 10-20 m
High precisionpartons in LHC
plateau
Low x parton
dynamicsHigh Density Matter
Large xpartons
Inclusive Kinematics for 70 GeV x 7 TeVInclusive Kinematics for 70 GeV x 7 TeV
s 1.4 V Te1.4 eV TW
710 at x 2 2 1 GeVQ
• High mass (Q2) frontier
• Q2 lever-arm at moderate x
• Low x (high W) frontier
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Event Rates: Ee x 7000 GeV
100 fb-1 70 GeV
10 fb-1 140 GeV
electrons positrons
Charged CurrentsNeutral Currents
2 times Ee compensates for 10 times the energy at highest Q212/Jan/2008 9
High x Partons と s
Full NC/CC sim (with systs) & NLO DGLAP fit …
… high x pdfs LHC discovery & interpretation of new states?… projected as precision few/mil (c.f. 1-2% now)
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Heavy QuarksHigh precision c, b measurements (modern Si trackers, beam spot 15 * 35 m2 , increased rates at larger scales). Systematics at 10% level beauty is a low x observable! s (& sbar) from charged current
bottom
(Assumes 1 fb-1 and- 50% beauty, 10% charm efficiency- 1% uds c mistag probability.- 10% c b mistag)
LHeC 10o acceptance
LHeC 1o acceptancestrange (A. Mehta, M. Klein)
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Useful general results: LHC Luminosities
D ~7%, (outside error band)
MW
Cteq6.5 err. band
Cteq6.1 err. band
MZ
W, Z production : really standard candles?
CTEQ 6.1 -> 6.5: Difference in HQ
treatment ：
Through the global fitting of PDF,
→ change in Gluon → change in Sea quark Change in W-production @
LHC
Wu-Ki Tung @ DIS2007
LHC data help to improve PDF.
I mpact of CTEQ6.5M,S,C PDF’s on stot’s at LHC
+
Yuan: EW-5
Higgs
<-SM
MSSM->
SUSY のパラメータ領域では、 陽子の中の b- クォーク分布が大きく効く場合もある。
― > SUSY パラメータの決定の上でも、重要になってくる可能性がある。
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Low x Low x MachineMachine としてのとしての LHeCLHeC
HERA からさらに low-xへ拡張できる。 ただし実験的には非常に難しい。 電子のエネルギーが高いために、 LowQ2 では散乱角が非常に小さい。 179 度 ― > Q2 ＝ 1GeV2 ただしルミノシティーはたいしていらない。
Saturation に答えを出せる（か？）
INCREDIBLELOW x
COVERAGE!
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HERA K
inem
atic
Lim
it
0
1
“pQCD” : parton evolution
“Hadronic”: Regge theory behavior of γp total cross section
HERA の場合
Donnachie & Landshoff
Gluck, Reyaand Vogt
Early ZEUS data showed rapid increase of F2 at low x.
Fixedtarget data
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F2 構造関数の測定
• x が小さくなると F2 は急激に大きくなる
– 陽子の中には soft ‘sea’ クォークがたくさんある
• Q2 が大きくなるにつれてその傾きは急になっている。
softer parton smaller resol.
dynamics of quarks and gluons
• 高い x では低エネルギーのデータとよくつながっている。
• DGLAP 発展方程式を使った NLOQCDはデータを非常に良く再現できている。
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FS04 Regge (~FKS): 2 pomeron model, no saturationFS04 Satn: Simple implementation of saturationCGC: Colour Glass Condensate version of saturation
LHeC の場合 : どの Saturation 模型か？Forshaw, Sandapen, Shawhep-ph/0411337,0608161
J. Forshow, P. Newmann
Saturation model 毎の違いを議論できるか？
― > もっと Study が必要
!! eA も可能 !!
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どうやって どうやって LHeC LHeC を実現するかを実現するか
• Previously considered as `QCD explorer’ (also THERA)
• Reconsideration (Chattopadhyay & Zimmermann) with CW cavities began
• Main advantages: low interference with LHC, Ee 140 GeV, LC relation
• Main difficulty: peak luminosity only~0.5.1032 cm-2 s-1 at reasonable power
• First considered (as LEPxLHC)in 1984 ECFA workshop
• Recent detailed re-evaluation with new e ring (Willeke)
• Main advantage: high peaklumi obtainable (1033 cm-2 s-1)
• Main difficulties: building it around existing LHC, e beam life
LINAC-RING RING-RING
ep と pp が同時に実験できるオプション以外はない。 電子加速器を建設する機会は LHC アップグレードのときのみ
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Ring-RingRing-RingParametersParameters
Top view
2 mrad
Non-colliding p beamVertically displaced
• LHC fixes p beam parameters
• 70 GeV electron beam, (compromiseenergy v synchrotron 50 MW)
• Match e & p beam shapes, sizes
• Fast separation of beams withtolerable synchrotron power requires finite crossing angle
• 2 mrad angle gives 8s separation atfirst parasitic crossing
• High luminosity running requires low focusing quadrupoles close to interactionpoint (1.2 m) acceptance limitation to 10o of beampipe
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Ring-Ring Design
• e ring would have to bypass experiments and P3 and 6• ep/eA interaction region could be in P2 or P8. 12/Jan/2008 22
alternative sites
6km
S. Chattopadhyay (Cockcroft), F.Zimmermann (CERN), et al.
Linac-Ring Design
(70 GeV electron beam at23 MV/m is 3km + gaps)
Relatively low peak lumi, but good average lumiEnergy recovery in CW mode (else prohibitive power usage)
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Plenary ECFA, LHeC, Max Klein, CERN 30.11.2007
Comparison Linac-Ring and Ring-Ring
Energy / GeV 40-140 40-80
Luminosity / 1032 cm-2 s-1 0.5 10
Mean Luminosity, relative 2 1 [dump at Lpeak /e]
Lepton Polarisation 60-80% 30% [?]
Tunnel / km 6 2.5=0.5 * 5 bypasses
Biggest challenge CW cavities Civil Engineering Ring+Rf installation
Biggest limitation luminosity (ERL,CW) maximum energy IR not considered yet allows ep+pp one design? (eRHIC) 2 configurations [lox, hiq]
e±p Luminosity
Linac-ring
Ring-ring
Timeline
● 2007: form working groups + steering committee initial meeting of conveners + committee
SAC overview● 2007/8: ECFA/CERN endorsement “work out”● 2008: workshop I ● 2009: workshop II LHeC CDR [LHC Committee] ● 2011: LHeC TDR
- construction 8 years ?- impact on LHC: civil engineering + installation e-ring and e-linac- be aware of CLIC progress
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Accelerator ExpertsS.Chattopadhyay, R.Garoby, S.Myers, A. Skrinsky, F.Willeke
Research DirectorsJ.Engelen (CERN), R.Heuer (DESY), Y-K.Kim (Fermilab), P.Bond (BNL)
TheoristsG.Altarelli, S.Brodsky, J.Ellis, L.Lipatov, F. Wilczek
ExperimentalistsA.Caldwell (chair), J.Dainton, J.Feltesse, R.Horisberger, A.Levy, R.Milner
Scientific Advisory Committee (SAC)
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Steering Group Oliver Bruening (CERN)John Dainton (Cockcroft)Albert DeRoeck (CERN)Stefano Forte (Milano)Max Klein - chair (Liverpool)Paul Newman (Birmingham)Emmanuelle Perez (CERN)Wesley Smith (Wisconsin)Bernd Surrow (MIT)Katsuo Tokushuku (KEK)Urs Wiedemann (CERN) + (increasing)
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Working Group Structure•Accelerator Design [RR and LR]
•Interaction Region and Forward Detectors
•Infrastructure
•Detector Design
•New Physics at Large Scales
•Precision QCD and Electroweak Interactions
•Physics at High Parton Densities [small x and eA]
Convenors 候補者にコンタクトを取っているところ ― > ぜひ参加を
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Plenary ECFA, LHeC, Max Klein, CERN 30.11.2007
Luminosity: Ring-Ring
LN p
4epn
Ie px py
8.31032 Ie
50mA
m
px pncm 2s 1
pn 3.8m
N p 1.71011
s p(x,y ) s e(x,y )
px 1.8m
py 0.5m
Ie 0.35mAP
MW
100GeV
E e
4
1033 can be reached in RREe = 40-80 GeV & P = 5-60 MW.
HERA was 1-4 1031 cm-2 s-1
huge gain with SLHC p beam F.Willeke in hep-ex/0603016: Design of interaction region for 1033 : 50 MW, 70 GeV
May reach 1034 with ERL in bypasses, or/and reduce power.R&D performed at BNL/eRHIC
Ie = 100 mA
likely klystroninstallation limitSynchrotron rad!1033
cf also A.Verdier 1990, E.Keil 1986
Plenary ECFA, LHeC, Max Klein, CERN 30.11.2007
Luminosity: Linac-Ring
LN p
4epn* P
E e11032
P /MW
E e /GeVcm 2s 1
pn 3.8m
N p 1.71011
* 0.15m
LHeC as Linac-Ring versioncan be as luminous as HERA II:
4 1031 can be reached with LR:Ee = 40-140 GeV & P=20-60 MWLR: average lumi close to peak
140 GeV at 23 MV/m is 6km +gaps
Luminosity horizon: high power:ERL (2 Linacs?)
Ie 100mAP
MWGeV
E e
Ie = 100 mA
High cryo load to CW cavities
s 2TeV
