Chris Parkes University of Manchester Part VI Concluding Remarks 1)Other flavour physics / CPV searches 2)Overall Constraints on CKM Triangle

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

Chris Parkes3 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 J PC =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.

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

Chris Parkes5 Spin reverses under T Dipole moment reverses under P So another way of finding CP Violation (and another good LHCb PhD thesis topic…)

Neutron Electric Dipole Moments Spin precession frequency of ultracold neutrons 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 Experiment at IIL, Grenoble from Sussex, RAL et al. Initially rom temp, now cryo. expt

CKM Measuring Parameters Triangle – Overall Fits

Chris Parkes8 CKM metrology  |V ud | : nuclear  -decay ~ (  )  |V us | : semileptonic kaon decays ~ (0.226  0.002)  |V ud | : nuclear  -decay ~ (  )  |V us | : semileptonic kaon decays ~ (0.226  0.002) 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 (  V ud 2 )

Chris Parkes9 Remember unitarity constraints – e.g. so can constrain for further generations of quarks from magnitudes only

Chris Parkes10 CKM metrology – constraints in the ( ,  ) plane Taken from the UTfit homepage: Kaons CPVB CPVB magnitudes only B Mixing B CPV

Chris Parkes11 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

Chris Parkes12 CKM metrology and UnitarityTriangle: Current Status There is still compatibility with the Standard Model ! Constraints from many CKM matrix complementary and independent measurements There is still compatibility with the Standard Model ! Constraints from many CKM matrix complementary and independent measurements

Chris Parkes13 Concluding remarks  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-constrain the 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  A lot of hope and expectation for the (near) future experimental results!