Chris Parkes University of Manchester

1. QUARK FLAVOUR PHYSICS Chris Parkes University of Manchester Part VI Concluding Remarks Other flavour physics / CPV searches Overall Constraints on CKM Triangle

2. Other areas of measurements made by quark flavour experiments not discussed yet: Spectroscopy Spectroscopy: X(3872)

3. X(3872) : Exotic State An area of quark flavour physics we haven’t discussed is searching for new meson states Mesons: quark, anti-quark Baryons: 3 quarks 50 year history of searching for ‘exotic’ states Belle discovered X(3872 MeV) 10 years ago, didn’t match any predicted mass state for a charm meson Subsequently a number of other states that don’t “fit” have been found LHCb 2013 – Measured JPC=1++ from analysing angles of decay products All but rules out that it is a conventional meson Possible exotic explanations of the X(3872) nature include: tetra-quark : di-quark di-anti-quark; or charmonium-’molecule’ mixture.

4. Other type of measurements sensitive to CP violation in quarks but not made by accelerator-based quark flavour experiments Dipole Moments

5. Dipole moment reverses under P Spin reverses under T So another way of finding CP Violation (and another good LHCb PhD thesis topic…)

6. Neutron Electric Dipole Moments Experiment at IIL, Grenoble from Sussex, RAL et al. Initially rom temp, now cryo. expt Spin precession frequency of ultracoldneutrons in a weak magnetic field. 1.Take neutrons from reactor at ILL 2. Slow them down and store (100s) 3. Apply weak magnetic field neutron spin precesses in magnetic field due to magnetic moment of neutron 4. strong electric field is applied also If an EDM this will interact and spin precession will speed up or slow down 5. Measure precession with NMR

7. CKM MeasuringParameters Triangle – OverallFits

8. CKM metrology How are the CKM parameters magnitudes (not phases) measured? • Magnitudes are typically determined from (ratios of) decay rates • E.g. compare decay rates of neutron and muon decays (  Vud2) • |Vud| : nuclear b-decay ~ (0.97380.0003) • |Vus| : semileptonic kaon decays ~ (0.2260.002)

9. Remember unitarity constraints – e.g. so can constrain for further generations of quarks from magnitudes only

10. CKM metrology – constraints in the (r, h) plane Taken from the UTfit homepage: http://www.utfit.org Kaons CPV B CPV Bmagnitudes only B CPV B Mixing B CPV

11. CKM metrology and unitarity triangle fit CKM Mechanism in SM proven to work Now a good way to discover new physics Over constraining triangle and compatibility of angle measurements

12. CKM metrologyand UnitarityTriangle: CurrentStatus There is still compatibility with the Standard Model ! Constraints from many CKM matrixcomplementary and independent measurements

13. Concludingremarks • CP violation is a fundamental broken symmetry • Needed for matter anti-matter asymmetry • It can be incorporated in the Standard Model, but seems like an “add-on”  SM cannot be the final answer nowhere near enough CP Violation in quark sector • Study of CP violation involves precise measurements of the CKM matrix • Present measurements allow to over-constrainthe CKM triangles and look for inconsistencies • Inconsistencies would be a sign for New Physics • And rare decays also an important method for searching for New Physics • Alot of hope and expectation for the (near) future experimental results!