Is B s 0 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 B s 0 and B s 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: Reaction Threshold [GeV] Charged-current  s=1 reactions, produce states containing a single strange meson.

Allowed processes: Reaction Threshold [GeV] But a qq pair such as bb or cc can be produced at higher threshold.

Allowed processes: 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 by associate production: 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 B s 0 produced. Lepton track gives location of production. B s 0 or B s 0 seen at decay point where: –decay identifies what it decayed as B s 0 or B s 0 –momentum of decay products gives momentum of B s 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 B s 0 –has advantage of 100% tagged at production. –what are the rates?