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Introduction to Charge Symmetry Breaking. Introduction What do we know? Remarks on computing cross sections for 0 production. G. A. Miller, UW. Charge Symmetry: QCD if m d =m u , L invariant under u $ d. Isospin invariance [H,T i ]=0, charge independence, CS does NOT imply CI. - PowerPoint PPT Presentation

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Introduction to Charge Symmetry BreakingIntroductionWhat do we know?Remarks on computing cross sections for 0 productionG. A. Miller, UW

Charge Symmetry: QCD if md=mu, L invariant under u$ dIsospin invariance [H,Ti]=0, charge independence, CS does NOT imply CI

Example- CS holds, charge dependent strong forcem(+)>m(0) , electromagneticcauses charge dependence of 1S0 scattering lengths no isospin mixing

Example:CIB is not CSBCI ! (pd! 3He0)/(pd ! 3H+)=1/2NOT related by CSIsospin CG gives 1/2deviation caused by isospin mixingnear threshold- strong N! N contributes, not ! mixing

Example proton, neutron proton (u,u,d) neutron (d,d,u)mp=938.3, mn=939.6 MeVIf mp=mn, CS, mpmp(mp-mn)Coul 0.8 MeV>0md-mu>0.8 +1.3 MeV

Miller,Nefkens, Slaus 1990

All CSB arises from md>mu & electromagnetic effects Miller, Nefkens, Slaus, 1990All CIB (that is not CSB) is dominated by fundamental electromagnetism (?)CSB studies quark effects in hadronic and nuclear physics

- Importance of md-mu >0, p, H stable, heavy nuclei existtoo large, mn >mp + Binding energy, bound ns decay, no heavy nucleitoo large, Delta world: m(++)
Importance of md-mu >0, influences extraction of sin2Wfrom neutrino-nucleus scattering

0, to extract strangeness form factors of nucleon from parity violating electron scattering

Outline of remaindercomments on pn! d0dd!4He0Old stuff- NN scattering, nuclear binding energy differences

NN force classification-Henley Miller 1977 Coulomb: VC(1,2)=(e2/4r12)[1+(3(1)+3(2))+3(1)3(2)]I: ISOSCALAR : a +b 12II: maintain CS, violate CI, charge dep.3(1)3(2) = 1(pp,nn) or -1 (pn)III: break CS AND CI: (3(1)+3(2))IV: mixes isospin

VIV(3(1)-3(2))(3(1)-3(2)) |T=0,Tz=0i=2|T=1,Tz=0i isospin mixingVIV=e(3(1)-3(2))((1)-(2))L +f((1)(2))3 ((1)(2)) Lmagnetic force between p and n is Class IV, current of moving proton ints with n mag momentspin flip 3P0!1 P0 TRIUMF, IUCF expts

md-muCLASS III:Miller, Nefkens, Slaus 1990meson exchange vs EFT?

Search for class IV forces A -see next slide

Where is EFT?ant

A=3 binding energy differenceB(3He)-B(3H)=764 keVElectromagnetic effects-model independent, Friar trick use measure form factors EM= 693 20 keV, missing 70verified in three body calcsCoon-Barrett - mixing NN, good a, get 80 10 keVMachleidt- Muther TPEP-CSB, good a get 80 keVgood a get 80 keV

Summary of NN CSBmeson exchangeWhere is EFT?

old strong int. calc.

np! d0Theory Requirementsreproduce angular distribution of strong cross section, magnitudeuse csb mechanisms consistent with NN csb, cib and N csb, cib, Gardestig talk

Gardestig, Nogga, Fonseca, van Kolck, Horowitz, Hanhart , Niskanenplane wave, simple wave function, = 23 pb 14pbBacher

Initial state interactionsInitial state OPEP, + HUGE, need to cancel Nogga, Fonseca

plane wave, Gaussian w.f. photon in NNLO, LO not included23 pb vs 14 pbet al

Initial state LO dipole exchanged*(T=1,L=1,S=1), d*d OAM=0, emission makes dd component of He, estimate using Gaussian wf 3P0

Theory requirements: dd!4He0start with good strong, csb np! d0 good wave functions, initial state interactions-strong and electromagneticgreat starts have been made

Suggested plans: dd!4He0Stage I: Publish existing calculations, Nogga, Fonseca, Gardestig talks, HUGE LO photon exchange absent now, no need to reproduce datapresent results in terms of input parameters, do exercises w. paramsStage II: include LO photon exchange, Fonseca

Much to do, lets do as much as possible here