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Views on Flavour Physics Opening Talk, DAFNE 2004 Laboratori Nazionali dell’ INFN di Frascati, June 9, 2004. Luciano Maiani, Universita’ di Roma La Sapienza. 100000. BNL (muon g-2) SPS (NA48). P-P, P-P-bar colliders. GeV. LHC. 10000. LHC. ions. ?. 1000. TEVATRON. SppS.
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Views on Flavour Physics Opening Talk, DAFNE 2004Laboratori Nazionali dell’ INFN di Frascati, June 9, 2004. Luciano Maiani, Universita’ di Roma La Sapienza.
100000 • BNL (muon g-2) • SPS (NA48) • .... P-P, P-P-bar colliders GeV LHC 10000 LHC ions ? 1000 TEVATRON SppS Flavour Physics HERA RHIC SLC LEP2 100 LEP PETRA + - ISR e e colliders PEP TRISTAN PEP2 VEPP-4 CESR 10 KEK-B CEA DORIS ADONE SPEAR Meson Factories BEPC DCI VEPP-2 CBX 1 DAFNE ACO AdA VEP-1 ~~ 0.1 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 Collider energies versus time L. Maiani. Views on Flavour Phyisics
SUMMARY • The muon g-2 • Semileptonic decays and CKM unitarity • A fresh look at the scalar mesons • Flavour physics: why continue? Very personal views Not systematic at all Apologies for omissions! L. Maiani. Views on Flavour Phyisics
Brookhaven National LabMuon g-2 Collaboration(Y. Semertzidis, ICHEP 2002) L. Maiani. Views on Flavour Phyisics
Electroweak: Hadron (CMD2 +KLOE): Light-by-light: Total SM: D = BNL, Muon g-2 Collaboration, 2004 Positive and negative muons combined L. Maiani. Views on Flavour Phyisics
Comparison CMD2-KLOE L. Maiani. Views on Flavour Phyisics
g-2, conclusions • The discrepancy is 3s, but huge, 2 x electroweak: improving on the error is mandatory and crucial; • The bad guy is light-by-light scattering: no perspective (at the moment) to get a “rigorous” estimate, • Nonetheless, an error of 4 10-10 is most likely conservative • It leaves margin to improvement by a factor 2-3 on the present error • More effort on R (at higher energy in particular) is justified • As well as another round of g-2 experiment at Brookhaven!! • The result may have fundamental implications on the planning of the next HE machine, beyond the LHC, with very low cost ! L. Maiani. Views on Flavour Phyisics
Unitarity of the weak mixing matrix Gino Isidori Workshop on the CKM Unitarity Triangle, IPPP Durham, April 2003 arXiv:hep-ph/0311044, Nov 2003. • Superallowed beta transitions in I=1, 0+ nuclei • Neutron beta decay: • Contribution of Vub is negligible • Cabibbo unitarity leads to the prediction : L. Maiani. Views on Flavour Phyisics
KLOE, 2004 L. Maiani. Views on Flavour Phyisics
New!!! KTeV (KLl3): Hyperon decays: NA48 data! [(KS)e3] L. Maiani. Views on Flavour Phyisics
CKM Unitarity (conclusions) • Isospin and SU(3) breaking seems to be under control with Chiral Perturbation Theory; • There is still some margin for improvement, to 0.1% errors (?) • A remarkable achievement. L. Maiani. Views on Flavour Phyisics
Spring-8, JP Q+ Exotic Baryon States T. Nakano et al.. hep-ex/0301020 Jul 2003 Evidence for Narrow S=+1 Baryon Resonance in Photo-production from Neutron V.V. Barmina et al.. hep-ex/0304040 Sep 2003 Observation of a baryon resonance with positive strangeness in K+ collisions with Xe nuclei. ITEP(RS) LNF(IT) Jeff. Lab, US S. Stepanyan et al. hep-ex/0307018. Dec 2003 Observation of an Exotic S = +1 Baryon in Exclusive Photoproduction from the Deuteron X- - CERN NA49 Collaboration hep-ex/0310014 Oct 2003 Observation of an Exotic S = -2, Q = -2 Baryon Resonance in Proton-Proton Collisions at the CERN SPS L. Maiani. Views on Flavour Phyisics
Roper resonance ? Are there mesons ? Bound diquarks [qq]? • Q+ was predicted in Skyrmion model (SU3 decuplet) • …what about quark model? • Bound-diquark idea revisited by Jaffe & Wilczeck • [qq] • is a boson! • [qq]+[qq] are in L=1 (at short distance they remember of fermionic constituents) • [qq]+[qq]+q-bar= L. Maiani. Views on Flavour Phyisics
A fresh look at the light scalar mesons Work in progress (L.M., A. Polosa, F. Piccinini, V. Riquer) • The a(980)I=1 and f(980)I=0 fit very well in the diquark picture - almost degenerate (Dm= 10-20 MeV) - a(980) decays in states with one strange quark pair (hp); To complete 8+1 we need: The first is s(480), claimed by many groups, seen well by KLOE in fp0p0g With s(480) and a(980) we find (quadratic masses) mK~770 MeV. The kappa is missing for the moment. A strange particle like this has been claimed.... it badly needs confirmation. Antisymmetric diquark explains inverted properties w.r.t. vector mesons: the isolated I=0 is the lightest state and likes to decay in pp !. L. Maiani. Views on Flavour Phyisics
Ms= f(1020)p0p0g Study of the Decay f(1020)p0p0g with the KLOE Detector The KLOE Collaboration arXiv:hep-ex/0204013 Apr 2002 L. Maiani. Views on Flavour Phyisics
p K-bar f(980) K* K p scalar meson decays Diquarks are color triplets, they cannot be separated! However, from time to time : The potential barrier becomes finite (if it exists at all!) and tunneling towards an outgoing pair of qqbar mesons is possible. The swich is described by a single amplitude, A. For s(480), and a(980), with A= 2.6 GeV,we find: G(s) =345MeV, G(a) = 43MeV,.....not too bad! The switch amplitude brings which is below threshold. Rescattering can bring to pp. Switch amplitude makes contact with K-Kbar molecule, but physics is different ! L. Maiani. Views on Flavour Phyisics
Heavy flavours Hidden charm: charmonium octet(??)+singlet .Possible decays: Open charm: Really spectacular signatures. L. Maiani. Views on Flavour Phyisics
Singlets are very difficult No real motivation Exotic baryons exist. Good signals: octets, inverted spectrum, .. states (conclusions) • Many open questions on scalar low energy mesons: • Consistent widths • Can we obtain a consistent picture of f(1020) Scalar + g • To clarify the issue of the s: gg pp may be very useful • Search of the k • Narrow states are seen by BABAR, CLEO and BELLE in charm containing hadrons: similar explanations? • Other exotic states have been considered in the past: • Gluon balls • Hybrid (gluons +quarks) • qq-qbar qbar • A rich spectroscopy at low energy, to be tested in heavy flavour systems. L. Maiani. Views on Flavour Phyisics
Views for the Future of CERNSymposium to celebrate the discoveries of Neutral Currents (1973) and of W&Z (1983)CERN, Geneva, September 16, 2003 Some resources available in CERN plan. • In a way, it is a trivial question…CERN’s future is the LHC: • Commissioning 2007; • Physics: 2007- 2022 (at least); • Consolidation programme • Luminosity upgrade can prolong LHC lifetime and extend its discovery potential by 15-30% in mass; • Energy upgrading rather costly and further in the future, as it requires the development of new high field magnets (Nb3Sn?15 Tesla ? ). • However: • Important HEP physics problems and corresponding scientific communities are not addressed by the LHC • Diversification is needed • e+ e - Linear Collider (subTeV): TESLA/NLC/JLC ? • Discussion must start now L. Maiani. Views on Flavour Phyisics
Flavour Physics: why continue? • Flavour Physics is very well (surprisingly!) alive • Time is ripe to decide how to continue: high luminosity at f, charm, B-factories? • This Conference is timely and important: we need to know more and better. • My personal view: • The LHC is coming soon, but the next HEP machine is not behind the corner; • keeping intermediate scale projects is important; • Flavour and neutrino physics projects have just the right size.... • And a very, very rich physics. GO FOR IT ! L. Maiani. Views on Flavour Phyisics