QUARK MASS EFFECTS

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QUARK MASS EFFECTS Non-vanishing mass breaks
chiral symmetry UP-DOWN QUARK MASS DIFFERENCES
CHARGE SYMMETRY examples mirror case n p
makes no difference, so Mn Mp, An(q)
Ap(q) self-conjugate case np Y dp0 fore-aft
symmetric near threshold, dd Y ap0 vanished
(isospin conservation)
Analyzing power differences in np elastic
scattering DA An(q) Ap(q) arise from
1) EM effects (neutron magnetic moment passing
proton charge) 2) Mn
Mp mass differences in OBE couplings
3) r0 w mixing driven
by md mu
Reconsideration of CSB using Chiral Perturbation
Theory gt term containing dm md mu gt EM
effects among quarks Several pieces of
information needed to constrain theory 1) Mn
Mp arises from dm and EM 2) near-threshold,
fore-aft asymmetry in np Y dp0 arises from dm and
EM Niskanen Few-Body 26, 241 found -0.37
considering p0 h, hN mixing van Kolck,
Niskanen, Miller PL B493, 65 add dm and (less)
EM to get 0.32 Analysis of TRIUMF experiment
underway 3) dd Y ap0 arises mostly from dm p0
h, hN contribution suppressed as odd-L pion
partial waves are excluded IUCF will look just
above threshold