Is Bs0 production by neutrino

interactions interesting?

Presented at the Super-B factory

workshop as an alternative approach

Nickolas Solomey

21 April 2005

Important because:• s-quark and b-quark

combination is calculable.

• CP violation is experimentally possible.

Physics Interest:• A golden mode to

study is Bs0 and Bs

0

– e+e- colliders produce it through ’’’’’

– hadronic production has poor tagging of what was produced.

– but

Production by neutrino has a possible advantage, but bringing its own difficulties.

Diagram:

proton

or

neutron

or e

qq pair

s-quark

or e

baryon

sq meson

u

Allowed processes:

p K+ p lepton 0.6 studied

n K0 p lepton 0.6 Can be used to test idea

n Ds

c+ + lepton 3.7 Maybe interesting

n Bs0

b0 + lepton 10.3 Study CP violation

Reaction

Threshold

[GeV]

Charged-current s=1 reactions, produce

states containing a single strange meson.

Allowed processes:

p K+ p lepton 0.6 studied

n K0 p lepton 0.6 Can be used to test idea

n Ds

c+ + lepton 3.7 Maybe interesting

n Bs0

b0 + lepton 10.3 Study CP violation

Reaction

Threshold

[GeV]

But a qq pair such as bb or cc can be produced at

higher threshold.

Allowed processes:

p K+ p lepton 0.6 studied

n K0 p lepton 0.6 Can be used to test idea

n Ds

c+ + lepton 3.7 Maybe interesting

n Bs0

b0 + lepton 10.3 Study CP violation

Reaction

Threshold

[GeV]

Possible future experiment at

Fermilab aims to study this

The s=q selection rule is enforced, so s-quarks

mesons are the only thing allowed with neutrinos.

Antiparticle produced only byassociate production:

p K+ 0 0 p lepton -

n Bs0

b+ lepton +

Reaction

•The s=q rule is very powerful.

•Neutrino and charged lepton used only as a tag, but it is 100%.

•The neutrino used, i.e. electron type or muon type, does not matter.

Analysis approach:

• Lepton charge and type of neutrino beam 100% tags if Bs

0 produced.

• Lepton track gives location of production.

• Bs0 or Bs

0 seen at decay point where:

– decay identifies what it decayed as Bs0 or Bs

0

– momentum of decay products gives momentum of Bs

0 to correct for c flight path.

• A b-Baryon confirms bb process.

Experimental needs:• Vertex detector of emulsion or layers of

silicon-tracking detectors.• Charged lepton identification of charge. • Decay products:

– Good momentum reconstruction to get invariant masses and flight path correction.

– Exceptional particle identification.

• The higher the neutrino beam energy the better since this will give a longer flight path in the lab-frame. (advantage of Beta beams)

Accelerator:• Neutrino Factory with

muons, very costly, long term 25+ years away.

• Modified Fermilab Tevatron with Radioactive heavy ion beams. Argonne Lab may be resource if they get the new RIA.

• Brookhaven National Laboratory has lots of experience with heavy ions in RHIC, since this experiment does not need a far detector the modification of the RHIC tunnel could be considered.

-Beam ring layout:

Problems:

• The neutrino rates would have to be high, but this is compatible with the needs of a far detector in the neutrino experiments.

• The near experiment would have to be of a high precision for both reconstructing decays and identifying particles.

Conclusion:• A future USA neutrino program may have:

– Detailed oscillation parameters measured.– CP violation search in Section.– Can b-quark physics be done?

• A -neutrino factory may be very far off in the future, but a beta beam by radioactive heavy ions is possibility.

• Take full advantage of other physics that can be done such as study of Bs

0

– has advantage of 100% tagged at production.– what are the rates?