HERA III and Experimentation off-site DESY · MK – report to KET meeting , DESY, 7. 10. 2003 Isolated Electrons and Muons with missing pt for pt > 25 GeV find 10 against 2.9+-0.5

MK – report to KET meeting , DESY, 7. 10. 2003

HERA III and Experimentation off-site DESY

•Introduction

•HERA III

•External Experimentation

Based on the HERA III Letters of Intent and Discussions in DESY‘s „Scenario Committee“

Max KleinDESY Zeuthen


The Temple “HERA 2” in Italy, Paestum

before after the Upgrade

The primary task at DESY (HEP) is to complete HERA 2: 1fb-1 + low Ep [the current estimate is 700pb-1 only by mid 2007]


Isolated Electrons and Muons with missing pt

for pt > 25 GeV find 10 against 2.9+-0.5

using 13.6 pb-1 e- & 104.7 e+

Multielectron Production • M(ee) > 100 GeV events SM (eq àeeeq) 2e 3 0.25 +- 0.05 3e 3 0.23 +- 0.04?

ZEUS: small tau excess

Things may evolve differentlythan now envisaged: anomalies?Consensus to reconsider plansIF new particles/ i.a.s were found


HERA III ?

•On site: continuation of HERA (low x, eD, eA, polarised eN)?

•Off site: participation in LHC, neutrino exp, eRHIC, …?

•Both roads have severe, but different consequences for DESY’s role in HEP.•The overriding goal for DESY’s HEP is to ensure the Linear Collider will be realised

•HC. Schultz-Coulon


•The potential of HERA is by far not explored with ep (HERAB/g/c)

•There is fundamental physics for 10 more years beyond 2007

• HERA is the largest microscope ever built and THE QCD machine par excellence with 1000 authors on H1, ZEUS and HERMES, 14% are DESY authors.


Physics at HERA III

•Low x ~ 10^-4: high density QCD at small coupling (CQC)

•Diffraction (p,n,D,A) and shadowing

•Mapping the 3D structure of strong interactions

•Precision measurements of parton densities (gluon, sea, valence)

•Parton dynamics and forward emission – BFKL?

•Saturation and nuclear parton densities – the black body limit

•HERA as a spin collider (low x Delta G, high Q2, …)

•New Concepts: Generalised parton distributions, DVCS, ?

•A new state of matter

•A key to confinement and the Higgs?

•A new detailed view on nucleon structure

•A must for the LHC and an unresolved problem

•A necessity to develop low x theory and find the limits of DGLAP

•A long predicted limit and a need to understand RHIC+ALICE

•A new world of hard QCD spin physics as in unpolarised case

•A consequence of ingenuitive theory and precision data


The H1 LoI is signed by 167 physicists from 42 institutes from 3 continents

9 German institutions represented

23 institutes are H1 members

The H1 LoI of June 28, 1985 had 23 institutes out of which 16 are still in the collaboration

Electron-Deuteron Scattering a Letter of Intentfor Experimentation with H1

April 2003, H1-04/03-609

http://hep.ph.liv.ac.uk/~green


A New Experiment for the HERA Collider

•24 Institutes and 65 physicists•Focus on low Q2 (0.1…100 GeV2), low x•Backward FL and forward parton radiation•ep, eD, eA, option for spin at low x•a new, dedicated apparatus based on dipole field

y

E/GeV

MPI-PhE/2003-06


Sample F2 data

Observation of hadron to parton transition

Hadron-hadronscattering results

hc/Q = 6.3 2.0 0.6 0.2 0.06 0.02 fm

F2∝ x-λ at small x

•HERA discovered high parton density (g,sea) at low Bjorken x


•Low x 1

Measurement of FL in the transition regionQ2 ~1 GeV2, low x: HIGH PRECISION, eID

This kinematic region is closed with GO/GG

•Test of ho QCD•Measurement of xg•Low luminosity à large part of HERA III does not need full year access!


Proton inf mom frame Proton rest frame

x=Q2/2P q fraction on P momentum carried by struck quark

τ = 1/2Mpx Lifetime of hadronic = W2/2MPQ2 fluctuations of photon

•Measure exclusive processes (VM production, DVCS) over wide W range to precisely pin down energy dependence of cross section. Need t-dependence of cross sections to get 3-D map of proton.

)'(2.0

ppfm

b−

≈

•transition from hadronic behaviour to partonic at 0.3 fm – why?


• extractions of PDFs assume at low x.

• plausible as both mu ~ 3 MeV and md~ 6 MeV


simulated accuracy (20pb-1 eD, 40 ep)

Exploration of the rise of F2(x,Q2)

Q2=5 GeV2

W−

pd

u

p

Parton luminosity problem at the LHC!

( )( )

( )

p n p12 2 22

1 1 1 1v v6 6 3 3

13

F F F

x d u d u

x d u at low x.

+ −

= − + −

≈ −


•Gribov: shadowing

•related to diffraction

•with p, n, D tagging learn much •more about diffraction

•Diffraction constrains shadowing à high precision low x en data

•Tagging of spectator p removes nuclear corrections at high x à determine uv/dv at large x


Investigate this region

Large effects are expected inForward jet cross sections at highrapidities (also for forward particleproduction (strange, charm, …)

More detailed tests of radiation in QCD: forward jets

•H1: instrument pipe/calorimeters New Detector: tracking+calo


eA scattering (low x)

nuclear parton distributions (RHIC, Alice)

. HgCaOdd ,,,, 4016r with Apb /5 1−

low x - field strength high, large Q2 – coupling weak à unitarisation effects à new phase of matter CGC

.

. deconfinement.--

)/ln(22 xQF δ∝

xAJ ])[/( ψσ

bj à black body limit

large diffractive cross section

no colour transparency

.--

exploratory at lowest x - unique due to high beam energies

p

A

pp

AA

Agg

Arg

rg 3/12

2

/

/=

ππ

laser (FEL!) cooling (Bessonov)


? ?Q2=3 GeV2 Q2=500 GeV2

measurement at high yQ2 dependence only viacombination of experiments

requires huge statisticsà Sources à HERA Lumi upgrade

large asymmetries in CC(also interesting for Transversity)

heavy flavourdiffractionSearches

longitudinal ep (D) polarisation in colliding mode – polarised eD: smaller an.mag moment!


The PRC congratulates the proponents for the studies presented in the EoI‘s describing measurements that would provide a significant step in the strong hadronic interactions. The PRC acknowledges the interest of a high precision measurement of FL, the investigation of the QCD radiation pattern over a wide range of eta, the improved understanding of the parton distribution functions, and agrees that many of the proposed measurements cannot be done at other existing or foreseen facilities. The PRC takes note that the present level of the theoretical understanding of QCD does not allow predictions of the proposed measurements at the level of precision achievable by the experiments. The PRC rates the HERAIII programm at lower priority than the Linear Collider Program.

[Draft Minutes of the Physics Research Committe on May 8, 2003]

•Statements by the PRC and the ESC on HERA III


Experimentation off-site DESY

…DESY wird weiterhin ein fuehrendes Zentrum der Teilchenphysik bleiben (bmbf 2/03)

•Time gap in data taking between HERA end (06/07) and LC start (15)•Too long for laboratory which needs to attract young and elder particle physicists

•Choice of experiment(s)/site should be driven by physics interest, by the expertise (exp+thy) and the role of DESY as a leading center for HEP

•DESY is attractive center to universities, MPI and international community (HERA)•If the LC does not come to HH, DESY, like other centers, needs to find a new role.

•Strategy group considered some obvious physics and site cases for external experiments.•Its task has not been to define off-site physics for DESY•There is no uniquely best choice:•Der Ozean des Unerforschten ist ueberall gleich tief (Newton)


DESY at the EMC, CERN

1974-1987 15 physicists and technicians left for HERA - when g1 was measured

696 citations

DESY-Z at L3 (1983-2003)

•Off site experimentation is not new to DESY


Indicative Physics Reach

Units are TeV (except WLWL reach) ILdt correspond to 1 year of running at nominal luminosity for 1 experiment

† indirect reach (from precision measurements)

PROCESS LHC SLHC VLHC VLHC LC LC 14 TeV 14 TeV 28 TeV 40 TeV 200 TeV 0.8 TeV 5 TeV 100 fb-1 1000 fb-1 100 fb-1 100 fb-1 100 fb-1 500 fb-1 1000 fb-1

Squarks 2.5 3 4 5 20 0.4 2.5 WLWL 2σ 4σ 4.5σ 7σ 18σ 90σZ’ 5 6 8 11 35 8† 30† Extra-dim (δ=2) 9 12 15 25 65 5-8.5† 30-55†q* 6.5 7.5 9.5 13 75 0.8 5Λ compositeness 30 40 40 50 100 100 400

Fabiola Gianotti: ICFA Seminar

à LHC has most attractive discovery potential – first time HEP accesses TeV scale.

1. The LHC


SM Higgs at the LHC

LHC leads from QCD to Higgs & BSM, from HERA to the LC


Hgap gap

b

b -jet

-jet

ηp p

beam

p’

p’roman pots roman pots

dipole

dipole

cross sections ~ 3 fb Khoze et al. (exclusive)~ 300 fb Boonekamp et al.(inclusive)

Diffractive Higgs Production: Clean signature - under study…

Another example linking HERA to the LHC:

join Totem ?


H→ZZ → µµee event with MH= 300 GeV for different luminosities

1032 cm-2s-1 1033 cm-2s-1

1034 cm-2s-1 1035 cm-2s-1

•SLHC: 1000fb-1/exp/year: > 2012, new trackers, 12ns bc, .. – too far away.?


•MNS matrix•Mass hierarchy•CP violation

•p decay (Weinberg 1979)

2. Neutrino Physics – Oscillation Experiments

dramatic recent progress

83.0)2(sin

1)2(sin

)(

109.6

105.2

122

232

212

25212

23223

≈Θ

≈Θ

+=∆

⋅≈∆

⋅≈∆−

−

msign

eVm

eVm

measure final 3 parameters

?,

?)(

?)2(sin213

132

==∆

=Θ

δnCPviolatiomsign


discussion focused on next generation, off axis oscillation experiments at (long distances from) JPARC and Fermilab

•HC. Schultz-Coulon


•Phase 1

•0.75MW•50kt S-Kamiokande•130d * 5y

•Phase 2

•4 MW•1Mt H-Kamiokande

•CP violation•p decay

006.0)2(sin

103

:

132

232

≈Θ

⋅≈∆

→− eVm

eνν µ

•hep-ex/0106019


•build/operate beams (E~0.7 GeV)•operate SK•build near detector (2km away: sc, 1kt C/LAr, muon)•prepare HK (8km south of SK, 500m water tank) [N*100, 10^35y in e+pi0] -phase 2

•Low energy elastic cc physics and backgrounds•Both the techniques and the physics are different from DESYs present


735 km

NuMi off axis - P929

•..faces some healthy competition from overseas activities

•Complement MINOS•LANNDD?

•hep-ex/0210005


hep-ph/0303081 M.Diwan et al., BNL, Pennsylvania, New York, Texas, Princeton

•Multiple (3) node observation: BNL-Homestake 2000km•AGS 28 GeV upgraded to 1 MW•500kt Cerenkov at Homestake (or at the Waste Isolation Pilot Plant)•wbb & VLBL: CP violation with neutrinos alone


•Future spin physics and eA at eRHIC@BNL (ELIC@JLAB)

Parameters e-ring

ion ring

p Au

C, m 1022 3833

E, GeV 5–10 250 100/u

nb 96 360

Nb 1⋅1011 1⋅1011 1⋅109

I, Aεrms,mmradβ*, cmσ*, mmξ

0.4545–25100.07–0.050.05

0.4517–9

270.07–0.05

0.005L, cm-2 s-1 (0.5-

0.9)⋅1033(0.5-

0.9)⋅1031

p

e2GeV (10GeV)

2-10 GeV

IP12

IP2

IP4

IP6

IP8

IP10

RHIC

beams in 2012?


Summary

•HERA II and the LC are THE present and strategic HEP priorities of DESY

•HERA III represents an interesting, high quality programme

•A physics programme at an external accelerator in collaboration with university groups is important for DESY to remain an attractive particle physics laboratory.

Documents

HERA III and Experimentation off-site DESY · MK – report to KET meeting , DESY, 7. 10. 2003 Isolated Electrons and Muons with missing pt for pt > 25 GeV find 10 against 2.9+-0.5