340 likes | 437 Views
GE neva LA ke T agged neu TRINO. Thoughts about tagged neutrino beam, GELATRINO proposal at LHC . Á. Fülöp, Z. Gilián and G. Vesztergombi Roland Eötvös University and KFKI-RMKI, Budapest, Hungary . Zimányi 2009 WINTER SCHOOL ON HEAVY ION PHYSICS Nov. 30. - Dec. 4., Budapest, Hungary.
E N D
GE neva LA ke T agged neu TRINO Thoughts about tagged neutrino beam, GELATRINO proposal at LHC Á. Fülöp, Z. Gilián and G. Vesztergombi Roland Eötvös University and KFKI-RMKI, Budapest, Hungary Zimányi 2009WINTER SCHOOL ONHEAVY ION PHYSICS Nov. 30. - Dec. 4., Budapest, Hungary
OUTLINES History FCNC Detector Expected rates Summary
Unknowns: decay point: ZD and momenta: Pp,Pm,Pn Shielding Decay zone Z XYTER-wall
Unknowns are only the momenta: PK,Pp,Pm,Pn Decay zone Shielding MAGNET XYTER-wall Possible e,m identification
http://accelconf.web.cern.ch/AccelConf/e96/abstracts/ass407a.pdfhttp://accelconf.web.cern.ch/AccelConf/e96/abstracts/ass407a.pdf
Wikipedia: Flavor_changing_neutral_current In theoretical physics, flavor changing neutral currents (FCNCs) are expressions that change the flavor of a fermion current without altering its electric charge. If they occur in the Lagrangian, they may induce processes that have not been observed in experiment. Flavor changing neutral currents may occur in the Standard Model beyond the tree level, but they are highly suppressed (the GIM mechanism). FCNCs are generically predicted by theories that attempt to go beyond the Standard Model, such as the models of supersymmetry or technicolor. Their suppression is necessary for an agreement with observations, making FCNCs important in model-building. Experiments tend to focus on flavor changing neutral currents as opposed to flavor changing charged currents, because the weak neutral current (Z boson) does not change flavor in the Standard Model proper at the tree level whereas the weak charged currents (W bosons) do. New physics in charged current events would be swamped by more numerous W boson interactions; new physics in the neutral current would not be masked by a large effect due to ordinary Standard Model physics.
This particle physics-related article is a stub. You can help Wikipedia by expanding it. Retrieved from "http://en.wikipedia.org/wiki/Flavor_changing_neutral_current" Categories: Particle
Above: Highly suppressed tau lepton decay via flavor-changing neutral current at one-loop order in the Standard Model. Below: Beyond-the-Standard Model tau lepton decay via flavor-changing neutral current mediated by a new S boson. Credit: Saul Cohen
Consider a toy theory in which a new bosonS may couple both • to the electron as well as the tau lepton via the term • The electric charge of S clearly must vanish, since the electron and • tau have equal charge. A Feynman diagram with S as the intermediate • particle is able to convert a tauon into an electron (plus some neutral decay • products of the S). The MEG experiment in Zurich will search for a similar • process, in which an antimuon decays to a photon and a positron. • In the Standard Model, such a process proceeds only by emission and • re-absorption of a charged W boson, which changes the tau into a neutrino • and then an electron, emitting a photon to conserve energy and momentum. • In most cases of interest, the boson involved is not a new boson S but the • Z boson itself (FCNCs involving the photon can't occur at zero momentum transfers • because of the unbroken electromagnetic gauge symmetry; as such, • FCNCs involving the photon at a nonzero momentum transfer are relatively • suppressed compared to FCNCs involving the Z boson). This can occur if the • coupling to weak neutral coupling is (slightly) nonuniversal. The dominant universal • coupling to the Z boson does not change flavor, but subdominant nonuniversal • contributions can.
Present proposal: electron muon Above: Highly suppressed tau lepton decay via flavor-changing neutral current at one-loop order in the Standard Model. Below: Beyond-the-Standard Model tau lepton decay via flavor-changing neutral current mediated by a new S boson. Credit: Saul Cohen
DETNI-A 157Gd/Si Detector Module Goals • 108 n/sec in 100 cm2 • with 2 views, 2 hit/strip:400 MHz strip hit rate • with 5 Byte/hit:2 GByte/sec data Consequences • 128 channel ASIC • 20 chip/module • 20 MHz/chip • 100 MByte/chip 100 mm slide courtesy C.J.Schmidt
Measurement of time, energy and position Data acquisition speed ~ 1Gbps Input Clock ~ 250MHz Input channels ~ 1024 or higher Data - 8-bit parallel after flash ADC ADC – Flash type 8-bit (MAX-106 600MSPS) Time stamp, channel-ID and status signals 32 bit(8-bit parallel x 4 packet) Understanding Data Acquisition System forN-XYTER www.gsi.de/documents/DOC-2007-Aug-28-2.ppt
L. Nodulman’s estimate: 105 tagged neutrino events/year GELATRINO has 1000 times larger detector material !!!! SIGNATURA: single muon track with exactly known energy = RANGE
At this preliminary stage it is hard to present precise numbers about the number of n-e elastic scattering events, but one can be sure that it should be many thousand times higher than in the CHARM-II experiment. Summary It is demonstrated that using Lake Geneva as target for high energy neutrinos originating from K0L decays produced in 7 TeV proton-nucleus interactions one can measure large number of tagged n-e interactions. Though one can reach considerable improvements compared to previous experiments, it remains open whether this will be enough to discover FCNC. More experimental and theoretical work is required. One should remark, however, that the tagging facility itself could be a gold-mine for the study of rare neutral kaon decays. Acknowledgement We wish to thank D. Nanopoulos and M. Mangano for enlightening comments on the present topic.
FCNCs involving the Z boson for the down-type quarks at zero momentum transfer are usually • parameterized by the effective action term • This particular example of FCNC is often studied the most because we have some • fairly strong constraints coming from the decay of B0 mesons in Belle and BaBar. • The off-diagonal entries of U parameterizes the FCNCs and current constraints restrict • them to be less than one part in a thousand for |Ubs|. The contribution coming from • the one-loop SM corrections are actually dominant, but the experiments are precise • enough to measure slight deviations from the SM prediction. • FCNCs are generically predicted by theories that attempt to go beyond the • Standard Model, such as the models of supersymmetry or technicolor. Their • suppression is necessary for an agreement with observations, making FCNCs • important in model-building. • Experiments tend to focus on flavor changing neutral currents as opposed to flavor • changing charged currents, because the weak neutral current (Z boson) does not • change flavor in the Standard Model proper at the tree level whereas the weak • charged currents (W bosons) do. New physics in charged current events would be • swamped by more numerous W boson interactions; new physics in the neutral • current would not be masked by a large effect due to ordinary Standard Model physics.