Meeting on the future of CERN 17 January 2001 Alain Blondel 1 A Neutrino Factory Complex Overview:...

1Meeting on the future of CERN 17 January 2001 Alain Blondel

A Neutrino Factory Complex

Overview: what is a neutrino factory Neutrino oscillation experiments P. HernandezR&D status and plans Other Physics opportunities Low energy muon physics Radioactive beams Kaon physics Short baseline neutrino experiments

Higgs colliders

Conclusions


Introduction

Since early 1990’s, -+ colliders have been considered an “economical” method to reach very high center-of-mass energies (Palmer et al, Muon collaboration).

A high energy muon collider was considered as possible future option for CERN. (Ellis Keil Rolandi 1999)

Nobody has ever build a muon machine and difficulties seem overwhelming to be tackled at once.

ECFA prospective study of muon storage rings (CERN 99-02 Autin,AB, Ellis)suggested a 3-step strategy:

1. NEUTRINO FACTORY

2. PRECISION MUON COLLIDER

3. HIGH ENERGY FRONTIER


Introduction



! each step has excellent physics in its own right !

1. NEUTRINO FACTORY• neutrino oscillations: 13,matter effects, CP violation• high intensity neutrino physics• high intensity low energy muon physics

2. PRECISION MUON COLLIDER• -> Higgs (Higgs factory)• -> H A (Susy Higgs factory) (CP violation, masses, widths& cross-sections)

3. HIGH ENERGY FRONTIER•. 4 TeV exploration with precise center-of-mass energy


Introduction



! And many problems to solve!

1. NEUTRINO FACTORY• high intensity proton driver and TARGET• muon COOLING in energy and Pt • FAST muon acceleration

2. PRECISION MUON COLLIDER• Much more cooling, and emittance exchange• both signs and 1 bunch each!• Decay electron background in storage ring

3. HIGH ENERGY FRONTIER•. Acceleration to 2 TeV•. Neutrino radiation


ECFA STUDIES -> END 2002

A Neutrino Factory Complex

Physics opportunities at the neutrino factory:A. Neutrino Oscillations (F. Dydak, J.J. Gomez-Cadenas)

B. High intensity hadron, muon and neutrino beams (J. Ellis) B1. and DIS (M. Mangano)B2. Rare muon decays and muon physics (G. Giudice)B3. High intensity Kaon physics (G. Buchalla)

Longer-term opportunities opened by the neutrino factory:C. muon colliders, (Marcela Carena, Bill Murray) C’.High Energy Frontier (coordinated with CLIC studies: J.Ellis/M.Battaglia)

In parallel with machine design studies by the Neutrino Factory working group mandated by CERN (H. Haseroth) + High intensity superconducting proton linac(R. Garoby) + Rapid cycling synchrotron and accumulator (H. Schonauer)


[….].the following requests to ECFA:

1. That ECFA should continue its support for studies of a European Neutrino Factory complex.

2. That ECFA should make a recommendation to proceed with intense accelerator R&D at CERN and with

other laboratories in Europe.

3. That ECFA supports continued international exchange of information and cooperation on these studies,

and in particular continues to sponsor the Fact series of workshops.

Following discussion, RECFA responded positively to these requests.

1. RECFA was impressed with the active machine and physics studies underway.It agreed to continue its support for these studies in the period 2001-2.

2. RECFA appreciated the extensive machine R&D already being pursued in acollaborative way by European laboratories, and by contacts with otherregions. It encouraged a continued coordinated effort in identifying andpursuing the necessary R&D efforts.

3. RECFA agreed to sponsor the FACT01 and FACT02 workshops.

ECFA recommendations, December 2000


-FACT’00

Emphasis on machine R&D

More concrete simulations

and critical look at physics case

Recently completed: FERMILAB physics study and feasibility study (incl. Cost drivers)

main conclusions:

1. Neutrino factory can be build 2. Chosen design is not cheap!

R&D necessary (est. 5 yrs)SPC nominated an Intl Working Group on muon beam search


CERN baseline scenario


Expected Physics outcome of a Long base Line programat a Neutrino factory

•Measurements of 13 , 23 with precision of 10-3 or limit at about 10-6 m13 with relative precision of 1% • (10 KT, 4 MW on Target, 1 Year)

•establish matter effect -> sign of m13

•Will be sensitive to CP violation over the whole Large Mixing Angle solution of the Solar neutrinos • (10 KT, 1 Year -> begin to touch)• (50 KT, 5 years -> whole region)

+ -> e+ e

High energy e essential & unique

-


The neutrino mixing matrix


Neutrino fluxes + -> e+ e

/ e ratio reversed by switching

e spectra are different

No high energy tail.

Very well known flux (aim is 10-3)

-- E& calibration from muon spin precession

-- angular divergence: small effect if 0.1/

-- absolute flux measured from muon current or by e e in near expt.

-- in triangle ring, muon polarization precesses and averages out.

polarization controls e flux:

+ -X> e in forward direction


CERN baseline scenario (target muon budget)

4 MW

2.2ms/13.3ms

3.3s

144b of 3ns

1016p/s

1.21014 s =1.2 1021 yr

0.9 1021 yr

3 1020 eyr

3 1020 yr

3 1020 eyr

3 1020 yr

1020 eyr

1020 yr


Many studies have become more concrete

Proton driver: SPL, high power Superconducting H- Linac Conceptual Design Report ready + Cost estimate 350.- MCHF HARP and MUSCAT: both had engineering runs and getting ready to take data in

2001. Future projects delineated.

RF tests in high radiation http://www.lbl.gov/Conferences/nufact00/docs/WG5_0525_Lombardi_sI.pdf 200 MHz cavity, up to 47 MV/m, near target 1.51013 26 GeV p.o.t.no breakdowns, some frequency shifts with ~10s time constant

Target tests: liquid target tests at CERN (being designed for ISOLDE beams -- or BNL)

solid target material tests with 100kW electron beams at RAL; proposal

Search teams for muon test beams and long baseline sites set-up

R&D on High intensity proton source and Neutrino Factory included in 4-year plan of CERN; N.F. supported at RAL and Frascati; HI machine in many European labs (M.A.F.@CEA+ ESS)


Detector must be underground=> search for possible sites (H. Wenninger et al )Gran Canaria (Spain); Spitzbergen (Svalbard,Norway);Center for underground physics Pihäsalmi(Finland)

P. Gruber

Best long baseline is around 3000kmfor CP violation + matter effects.

Search for long-baseline detector laboratories

Svalbard

Pihäsalmi


B. Autin, K. Bongardt (FZ-Juelich - D), R. Cappi, F. Caspers, E. Chiaveri, R. Garoby, F. Gerigk, H. Haseroth, C. Hill,

A.Krusche, D. Kuchler, M. Lindroos, A. Lombardi, R. Losito,H.Ravn, R. Ryne (Los Alamos), R. Scrivens, M. Silari,

M. Vretenar, J. Tuckmantel, M. Paoluzzi, M. Poehler, J.Pedersen

CEA (DAPNIA @ Saclay) - CNRS (IN2P3 @ Orsay & Grenoble)

SPL STUDY GROUP MEMBERS:

COLLABORATION:

SPL STUDY TEAM

R. Garoby muon week 24-10-2000


SPL layout

H- RFQ1 chop. RFQ2RFQ1 chop. RFQ2 RFQ1 chop. RFQ2DTL SCDTL RFQ1 chop. RFQ2 0.52 0.7 0.8 LEP-II dump

Source Low Energy section DTL Superconducting low-

45 keV 7 MeV 120 MeV 1.08 GeV 2.2 GeV

2 MeV 18MeV 237MeV 389MeV

10m 78m 334m 357m

PS / Isolde

Stretching andcollimation line

Accumulator Ring

Superconducting 1



SPL layout on the CERN site (top view)



SPL power consumption

NOMINAL(PULSED @ 75 Hz)

CONTINUOUSBEAM

Mean beam power 4 MW 24 MWElectrical power consumption:- RF (mean RF power)- Cryogenics (cooling power at 4.5 K)- Cooling & ventilation- Other & general servicesTotal electrical power consumption:

24MW (12 MW)8 MW (32 kW)2 MW4 MW38 MW

64 MW (32 MW)20 MW (75 kW)6 MW5 MW95 MW


A very potent machine indeed!


Università degli Studi e Sezione INFN, Bari, ItalyRutherford Appleton Laboratory, Chilton, Didcot, UK Institut für Physik, Universität Dortmund, Germany

Joint Institute for Nuclear Research, JINR Dubna, RussiaUniversità degli Studi e Sezione INFN, Ferrara, Italy

CERN, Geneva, Switzerland Section de Physique, Université de Genève, SwitzerlandLaboratori Nazionali di Legnaro dell' INFN, Legnaro, Italy

Institut de Physique Nucléaire, UCL, Louvain-la-Neuve, BelgiumUniversità degli Studi e Sezione INFN, Milano, Italy

Institute for Nuclear Research, Moscow, RussiaUniversità "Federico II" e Sezione INFN, Napoli, Italy

Nuclear and Astrophysics Laboratory, University of Oxford, UKUniversità degli Studi e Sezione INFN, Padova, Italy

LPNHE, Université de Paris VI et VII, Paris, FranceInstitute for High Energy Physics, Protvino, Russia

Università "La Sapienza" e Sezione INFN Roma I, Roma, ItalyUniversità degli Studi e Sezione INFN Roma III, Roma, Italy

Dept. of Physics, University of Sheffield, UKFaculty of Physics, St Kliment Ohridski University, Sofia, Bulgaria

Università di Trieste e Sezione INFN, Trieste, ItalyUniv. de Valencia, Spain

HARP experiment PS214Status Report to the SPSC, 31/10/2000

22 institutes

107 authors

Lucie Linssen SPSC 31-10 2000


Hadronic production cross sections (d/dPt.dPl) at various energies and with various targets

Goal: 2% accuracy over all phase spaceO(106) events/setting, low systematic error

CERN PS, T9 beam, 2 GeV/c – 15 GeV/c

"Stage 0"Technical run with partial set-up, 25 September – 25

October 2000Stage 1Measurements with solid and crygenic targets, 2001Future plans: Measurements with incoming Deuterium and Helium,

2002

~100 GeV incoming beam, using NA49 set-up

HARP will measure......



Experimental setup

drift chambers

cherenkov

TOF wall electronidentifier

spectrometermagnet

TPC solenoidmagnet

forward triggerforward RPC

muonidentifier

beam



HARP technical run



MUSCAT a muon scattering experiment

aluminum lithium

Agreement gets worse for light Z, no data for Hydrogen => measure!


MUSCAT

MWPC’s will be replaced by scintillating fibers=> t.o.f. measurement allows energy meast. Study dE/dx straggling vs scattering angle


Target studies

Liquid jet Beam test of Hg target (Isolde or BNL)


Ideally a muon is stopped by passing through some material and is being accelerated in the forward direction.

Because it would have decayed in the meantime, only some reduction in longitudinal and transverse momentum is applied. The longitudinal momentum is being replaced again by RF acceleration.

Problem: Heating because of multiple scattering.

Principle of Ionisation Cooling


beam in

beam out

Layout of 40/80 MHz Cooling Channel (CERN scenario)


Ionisation COOLING

COOLING: baseline scenario defined; simulations in progress [ Fermilab study lost factor 4 from paper study to engineered realistic set-up

(this was due to mismatches => iterations needed!)] ionisation cooling of muons has never been done before => Cooling test experiment needed

build- assemble- put into beam- operate a section of foreseen cooling channel

show that it performs (cools) as expected. Need: beam RF H2 absorbers Solenoids instrumentation

Large project; will require collaboration accelerators/experimenters across Europe international

Discussions started to define project (next: CERN 23 January) Intl workshops on instrumentation (next: London 23-24 February)aim: written proposal in spring 2001; in beam in 2004/2005.


MUON Yield without and with Cooling

Note: Calculations have still to be made with the detailed field configurations!

What muon cooling buys


Generic layout of a cooling test expt.

Est. order of magnitude: 30m, 30MV, 30 M


Conclusions (accelerator)

There is a scheme for a neutrino factory that seems well adapted to CERN. by no means final it requires still a lot of work in order to assess feasibility.

It is intended to continue this study and to fill in the remaining gaps. Future work may well show that some elements of this scenario need substantial modification or even replacement by other components.

The results of the HARP experiment expected for next year may also provoke some modifications.

The next steps ought to be:

the refinement of simulations, engineering designs and a cooling experiment for which we need a strong international

collaboration*H. Haseroth ECFA, december 2000


Could begin as soon as SPL/accumulator is build:

-High intensity low energy muon experiments -- rare muon decays and muon conversion (lepton Flavor violation) -- GF, g-2, edm, muonic atoms, e+ e-

--> design of target stations and beamlines needed. - 2d generation ISOLDE (Radioactive nuclei) -- extend understanding of nuclei outside valley of stability -- muonic atoms with rare nuclei(?)

if a sufficient fraction of the protons can be accelerated to E>15 GeV:-High intensity hadron experiments -- rare K decays (e.g.K-> )

In parallel to long baseline neutrino experiments:-short baseline neutrino experiments (standard fluxes X104) -- DIS on various materials and targets, charm production

-- NC/CC -> mw (10-20 MeV) e e & ee ee -> sin2weff (2.10-4)

--> design of beamline + detectors needed

Other physics opportunities at a -factory complex

Related to high intensity


Rare muon decays

Lepton flavor violating processes e, eee , e- observation of any of these decays would be A MAJOR DISCOVERY

From mixed neutrino loops: completely negligible rates (10-50) Rate in vicinity of observability due to SUSY loops

Or new (e.g RPV) interactions -- four-fermion operators

http://wwwth.cern.ch/stoppedmuons/stoppedmuons.htmlGian Giudice et al


Rates for e


The lepton flavor violating processes are not redundant

Loops

New 4-f Int.

Loops

New 4-f Int.


Present lines of thought for High Intensity Low Energy muon beams

1. Thin inner target in proton accumulator advantages: very efficient use of proton beam, point source difficulties: - can target take the heat? - creates high-radiation area inside ring 20 - 120

PSI already has 1 MW DC beam of 590 MeV protons with 5%I target for muons. How can one do 1000 times better?

2. Or Use full DC SPL 24 MW with thin muon target

DC beams (e, eee)

20

+ solenoid collection (1/.16)2 =40+ better experiments ?

Pulsed beam (e-1. Use proton beam from buncher2. Use muons at the end of cooling channel!

--> need now conceptual design of target station and muon beams


Thoughts for muon targets in neutrino factory complex

1. Use SPL DC beam and thin transmission target

2. Use beam stored in accumulator and inner target

2. Use cooled muon beam

1. Use bunched proton beam


Exp. Hall 1

Exp. Hall 2

Hall 3

A Radioactive Nuclear Beam (RNB) Facility: 2d Generation ISOLDE

SPL should eventually increase the intensity of secondary RNB’s by factor 100-1000

p

Heavy target

ISOL: Isotope Separation On Line

NUPECC WG R. Siemssen et al

Isotopes separated by e.m. devices

Post-accelerator High quality low energy RNB


Protons for 2d generation Isolde can be extracted from linac at various energies


Applications:

Fundamental nuclear physics: search for heaviest nucleus, island of stability(114 or 126?) excited nuclei (n-rich) far from stability line;data for nuclear astrophysics;atomic physics (atomic levels and APV with atoms with rare nuclei, muonic atoms);nuclear solid state physics

…… see NuPECC WG report on Radioactive Nuclear Beam Facilities: http://www.nupecc.org

to come: EURISOL.


More protons and more brilliant beams at CERN

More protons @ CERN

-- Higher intensity conventional beams target and systematics limited, however

-- fixed target experiments KAON physics (G. Buchalla et al http://buchalla.home.cern.ch/buchalla/kaonwww/kaon.html )

Holy Grail: KL very cleanCP violating process B=1.9 10-10 . = 4. 10-9 | Vub/Vcb|2 sin2CKM

also: KL ee CP violating process KL e lepton flavor violationOptimum proton energy: around 20 GeV, at least 1 MW to be interesting

--> now, understand how to do this


Neutrino scattering experiments

Event rates very high. High energy + small ring preferred

M. Mangano et al http://mlm.home.cern.ch/mlm/mucoll/nudis.htmlare evaluating in realistic way performance of possible experiments.

=> detector must measure scattered as well ase

Big gains of precision in -- DIS structure functions -- nuclear effects, -- Higher twist effects -- QCD fits -- Polarised structure functions (neutrinos ARE polarised! Polarised targets) ELECTROWEAK STUDIES -- NC/CC (efficient electron ID crucial here!)

-- e e & ee ee -> sin2weff (2.10-4)


Neutrino fluxes at near-by detectors

Set-up:

L 2.RIntegrated event rates 2.108/kg/yearprefer small ring, short straight-sections

d


deuterium deuterium_

hydrogen hydrogen_

Sort out nucleon spin structure


Precision physics with neutrinos

e e & ee ee

107 events/year in L=20m R=20 cmliq. scintillator detector

beam much better. ->

flux normalization crucial. 10-3 allows sin2w

eff = 2.10-4

Noted: e e provides

absolute normalization of beam w 108 evts/yr (carry over to beam?)

Accept e above Emin

N (NC/CC-> mW) under study


Step 1 towards muon collider(s)

Higgs and top factories

benefit from Higgs couplings ( higgs m2)

and superior energy calibration/resolution ideal for mh= 115 GeV/c2 ! and for study of Susy Higgses H,A (masses, widths, couplings and CP violation) --> experimental feasibility needed (backgrounds, efficiencies,etc.)

Energy frontier (synergy with CLIC studies)

Beyond -factory


From neutrino factory to Higgs collider

h (115) Upgrade to 57.5 GeV

Separate & , add transfer lines

More cooling + E/E reduction

Muon collider: a small…. but dfficult ring


Higgs factory h(115)

- S-channel production of Higgses is unique feature of Muon collider- no beamstrahlung or Synch. Rad., g-2 precession

=> outstanding energy calibration (OK) and resolution R=DE/E (needs ideas and R&D, however!)

mh=0.1 MeVh=0.3 MeVh->bb /h = 1%

very stringent constraints onHiggs couplings (b)


Higgs Factory #2: H, A

SUSY and 2DHM predict two neutral heavy Higgs with masses close to each other and to the

charged Higgs, with different CP number, and decay modes. Cross-sections are large. Determine masses & widths to high precision. Interference or “wrong decays”-> CP violation

Telling H from A: bb and tt cross-sections(also: hh, WW, ZZ…..)


CP violation in Higgs sector

a

(if CP conserved)h

CKM and cannot explain baryon asymmetry. Higgs system is a natural place to look.

Effects are very small in SM, MSSM (loops), but could be larger in generalM= 3X3 matrix of Higgses with different CP numbers

Light Higgs:polarization asymmetries

Vs

Vs

or

Heavy Higgs: any mixing/interference between H and A => CP violation


Much to do!

-- R&D for long baseline detectors

-- target stations & beam designs for stopped muon physics

-- beam design for near-by neutrino physics

-- nufact target tests (collection system must be integrated)

-- cooling test facility

-- etc etc

project has many facets; ideal to European competence

world wide: communication takes place already (NUFACT series) formal collaboration under discussion


Upcoming general muon meetings

7-10 May at CERN

24-30 May: -FACT01 in Tsukuba (Japan)

15-18 October 2001 at CERN

http://www.cern.ch/muonstoragerings


Possible NUFACT road map

->spring 2001 … … physics: (r)define muon top energy and detector locations search/define muon test beam study/evaluate instrumentation study/evaluate possible cooling test expt/facility(COOTEF)

March 2001 yellow report from CERN-ECFA study April 2001 Nufact feasibility study #2 BNL/MC (Europe participation?)

spring 2001 NUFACT’01 propose cooling test-experiment/facility launch studies of detectors for NUFACTexpts

summer 2001 HARP& MUSCAT physics run; first results: end 2001 US: Snowmass01; ECFA discussions on future of HEP in Europe


2001-2004 build components of COOTEF beam/RF/solenoids/H2 tanks/instrumentation 2004 begin operation of COOTEF

results from KAMLAND/SNO/Borexino (LMA or no LMA?)

summer 2005 results from COOTEF

2005-2006 -FACT - Design Report

2006-2007 finalize design of NUFACT and prepare detector proposals 2008 approval of NUFACT and examination of expts proposals

2009 begin construction of NUFACT and detectors.

Possible NUFACT road map

A.B. September 2000


Conclusions

NuFact Complex addresses essential physics issues that will not be addressed by High Energy colliders (LHC, NLC/Tesla): -- lepton number violation (mixing, rare muon&K decays) -- new CP violation phenomena (neutrinos, Higgses) and offers a large variety of physics opportunities and synergies -- high intensity neutrino physics -- nuclear physics (muonic atoms, radioactive nuclei, etc..)

AN ATTRACTIVE OPTION FOR EUROPE AFTER LHCStudies have become considerably more concrete over the last year thanks to an active and motivated community

There is a scheme for a NuFact that seems well adapted for CERN.Much work remains to be done to ascertain performance and.. Simply learn how a muon machine could work

Meeting on the future of CERN 17 January 2001 Alain Blondel 1 A Neutrino Factory Complex Overview:...

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Transcript of Meeting on the future of CERN 17 January 2001 Alain Blondel 1 A Neutrino Factory Complex Overview:...