Intensity Frontier Prospects atFermilab

Douglas Bryman
University of British Columbia
JSPS Fellow

Tevatron → LHC; TeV Energy Scale
New Physics

High MassScales?
COSMOLOGICALEVOLUTION, BBN

LEPTOGENESIS?

Rare Decays and CP violation
Symmetry Violation
NEUTRINO PHYSICS

Intensity Frontier Focus* Neutrino Physics: Oscillations:sinθ13 (if it's large enough);intense beams to DUESL;CP Violation; scattering* Muon Physics: µe Conversion <10-17 ; g − 2 (20 x)* Rare K Physics: K + → π +νν and K L0 → π 0ννOther Topics:* p Physics: QCD, searches for new physics using hyperons
and charmed mesons, antihydrogen.
* Charm Mixing and CP Violation at the Tevatron;
D-mixing, 70K events/yr.

Intensity Frontier at Fermilab:
Now and in the Future
Now:
Main Injector Neutrino Program (MINOS,Miniboone,Minerva,NOVA)
8 GeV Booster: Proposals Mu2E (10-16 ), g-2 (4x), ...
Tevatron Stretcher: K → πνν ? + ...
Future:Project XTevatron Stretcher
Mike Syphers• Tevatron can be use as a stretcher for providing
120 GeV beams to the existing Fermilab switch yard.
• MI: 120 GeV, 1.33 s cycle time, 2 pulses->Tevatron• 100 Tp could be stored in the Tevatron for slow
extraction using resonant extraction.
• 10% of the available beam would produce 70 kW with aduty factor of 95% over a 27.6 s cycle time.

Project X – which one?

Collage Stolen from Jonathon Bagger

PROJECT X: Search for theChosen One: An on-line
spiritual community thatshares personal supernaturalexperiences.

Steve Holmes
APT seminar 2008

Project X Facility Overview
Project X is a high intensity proton facility aimed at supporting aworld leading program in neutrinos and rare decays.
NOνA initially,
DUSEL later?
8 GeV slow spill
200 kW
2.2E14 protons/1.4 sec

120 GeV fast extraction
2.3 MW
1.7E14 protons/1.4 sec

Flavor and low
energy neutrino
programRecycler
3 linac pulse/fill

0.4 GeV
0.4 - 8 GeV
Front End ILC style linac

Main Injector
1.4 sec cycle

Stripping Foil

ILC Style 8 GeV H- Linac:
9mA x 1 msec x 5 Hz

Single turn transfer@ 8 GeVSteve Holmes
APT seminar 2008

Project X Accelerator Summary•The Project X design concept supports a long term future for Fermilab
based on world leading facilities at the:– Energy Frontier– Intensity Frontier•

Design concept exists for a facility with >2 MW beam power at 120 GeV,
simultaneous with 200 kW at 8 GeV.
– Major sub-system performance goals established– Supports world class program in neutrino physics and rare processes•

Design provides flexibility to support a long-term future for accelerator
based physics at Fermilab– Potential upgrade paths to mulit-MW at 8 GeV exist– Design aligned with needs of ILC technology development– Design concept supports future development of muon facilities

8 GeV

Proposals:

μ N → e N at 10−−−16

Lobashov (1980): Solenoid Pion Collector; flux x 1000.

BNL MECO → Mu 2 E
μ → e Conversion at Fermilab

μ → e Conversion
COMET at JPARC• Singles experiment mitigates high rates.

• Background (decay-in-orbit) known and calculable.
• High resolution detector feasible.
• Possible improvement x 104

K → π νν and K → π νν++0L

0Possibilities at Fermilab
MI+Tevatron Stretcher and Project X
Requirements:• High intensity, high duty factor• Low energy K+ beams.
• Pulsed beams for Neutral K TOF• Exploit advances in instrumentation
Goals and opportunities:>1000 events attainable in 3-5 years:<3% precision, comparable to theory++K→πνν at Fermilab/Tevatron Strecher:
New opportunity:

Stopped K technique:1000 events!

Principal Improvement: Lower Pk ~450 MeV/c
Only modest upgrades to the methods of E949 needed.

• 4-5 x higher stop efficiency at low momentum• Improved Acceptance (x5)
• Reduced randoms and accidental spoiling ofevents (photon veto) due to low momentum.

Assumptions and Issues for a new
K + → π +νν Measurement at Fermilab• New high acceptance short Kaon beam (E949):
14.6 (19) m; 18 (12) msr; 400-550 (710) MeV/c
2 x total acceptance relative to LESB3 at the AGS;
4-5 x efficiency for stopping kaons• Detector Improvements. Finer segmentation of RS(4-10x) for suppression of muon background; newelectronics, DAQ improvements.
>5 x acceptance of E949.
• Reduced Accidental losses from photon veto hits
due to low momentum.
Net gain: >200 SM events/yr (100 x E949). Proven technique.

Compact High Field System for K → π νν++Major Improvement of E949
Techniques for Project X• Low PK ~400 MeV/c for high stopping efficiency• Sci-Fi target and range stack for high rateπ → μ → e measurements• High acceptance and precise
momentum measurement to suppressγ Veto2-3Tπ+K + → π +π 0 , K + → μ +ν backgrounds• "Ideal" homogeneous photon vetoe.g. LXe 20 X 0Range StackLow mass tracker

K → π νν
++FNAL“Booster”(20 kW)

FNAL
TevatronStretcherFNAL

12%MIProjectX

Events/yr*

40200325

Events/5yr

200

1000

1600

Precision**

83.6

3*Estimates based on extrapolation of BNL E949.
** Includes separate estimates of backgrounds in Regions I (10%) and 2 (75%).

K → π νν Experiment Concept
0L0120GeV or 8 GeV Protons200 ps

K → π νν0L

• Use TOF to work in the K 0L c.m. system• Identify main 2-body background K 0L → π 0π 0
• Reconstruct π 0 → γγ decays with pointing calorimeter• 4π solid angle photon and charged particle vetos0K → π νν
0L0High intensity of Project X is ideal for the TOF-based KLexperiment.
– Small aperture, symmetric beam - makes forsimpler, higher acceptance detector– Exploit advances in instrumentation• 300 events/year at 1st stage of Project X; 3%
precision possible after 5 years.
• 5 times higher intensity could be used to get ~900
events/year• Similar possibilities may be available with theMI+Tevatron Stretcher approachTOF-based experiment
Intense source of protons (e.g. J-PARC, Project X) allows
a low energy approach to studying K + → π +νν (à la KOPIO)
Low energy
beam comes inshort bursts
Beam very narrowfor extra constraint
40 ns between
microbunches

γ directions
as well as E
measured

A major issue in the KOPIO design was the very wide beam.

KOPIO Challenge #1: Beamline• Complex, costly
series of collimators• 3 large sweepingmagnets• Plenty of aperturefor particles created
upstream to reachfiducial region•“Difficult” vacuum
vesselL. Littenberg

Small Beam: Many Advantages•••••••••“Difficult” vacuum vessel disappears
Geometric acceptance increases since horizontal planeaccessible
Beamline simpler, cheaper, better
Upstream background disappears, so do some types ofbackground in the fiducial volume
Same micro-bunch event spoilage disappears
Random vetoes much reduced
Extra kinematic constraint increases S/B
Beam veto probably unnecessary
Beam spoiler probably unnecessary– Gives 72% more kaons/proton– Much reduced neutron spreading•

Detector can be symmetrized, geometric acceptance increased
L. Littenberg

Sensitivity of Small Beam Exp.
• At 1st stage ProjectX, 300 equivalent
events per year
• Can get to 900
equivalent events
per year using 60%of 2nd stage ProjectX• Experiment mighteven be improved
beyond this…

1000
900
800
700
600
500

Series1400
300
200
10001122334455667

78

89 100Intensity relative to the Booster

Kaon Experiment Issues• Details of schemes for delivering ~100% duty factor.
• Uncertainties in low energy K production cross-sections
at 8 GeV and 120 GeV.
• Micro-bunching and neutrons at 120 GeV production.
• Dual targeting for charged and neutral experiments
appears feasible but needs examination.
• Some detector technology R&D would be valuable.
• Further development of CKM parameters (from theoryand B physics) needed for 3% measurements.

Summary* Fermilab has great potential for contributing to the intensity frontier:
Neutrino Physics -- oscillation phemomenolgy
Muon (mue Conversion, g-2) and Kaon Rare Decays (K → πνν )* Significant work can be done with existing facilities:
MI, Booster and MI+Tevatron Strecher* Project X promises to provide extraordinary opportunities fornew physics discovery

AcknowledgementsMaterial in this talk was taken from Project X
workshops and other talks by L. Littenberg,
R.Tschirhart, Mike Syphers, and Steve Holmes