arXiv subjects

Harry. J. Lipkin

Publications and source records attributed to Harry. J. Lipkin.

4 recordsLinked to original sources

arXiv2004

A Mass Inequality for the $Ξ^*$ and $Θ^+$ Pentaquarks

We derive an upper bound on the mass difference between the $Ξ^*$ and $Θ^+$ pentaquarks which are the manifestly exotic members of the $SU(3)_f$ antidecuplet. The derivation is based on simple assumptions about $SU(3)_f$ symmetry breaking and uses the standard quantum mechanical variational method. The resulting rather robust bound is more than 20 MeV below the experimentally reported $Ξ^*-Θ^+$ mass difference, emphasizing the need for confirmation of the experimental mass values and placing strong constraints on quark models of the pentaquark structure.

hep-ph↗

arXiv2002

Puzzles in Hyperon, Charm and Beauty Physics

Puzzles awaiting better experiments and better theory include: (1) the contradiction between good and bad SU(3) baryon wave functions in fitting Cabibbo theory for hyperon decays, strangeness suppression in the sea and the violation of the Gottfried Sum rule - no model fits all; (2) Anomalously enhanced Cabibbo-suppressed $D^+ \to K^{*+}(s\bar d)$ decays; (3) anomalously enhanced and suppressed $B \to η' X$ decays; (4) the OZI rule in weak decays; (5) Vector dominance ($W \to π, ρ, a_1, D_s, D^*_s $) in weak decays (6) Puzzles in doubly-cabibbo-suppressed charm decays.(7) Problems in obtaining $Λ$ spin structure from polarization measurements of produced $Λ$'s.

hep-ph↗

arXiv1993

Physics at B-Factories

The main motivation for B factories is the investigation of CP violation. We consider two questions: 1) Why has there been essentially no experimental progress in CP violation in the 28 years since its discovery in 1964? 2) Why do we expect better results from B factories?

hep-ph↗

arXiv1993

Interference Effects in B-Decays to Flavor-Mixed Neutral Mesons - Clues to Small Amplitudes and CP-Violation

CP violation can be observed in B decays when a given process depends upon interference between two weak amplitudes which have different $CP$-violating phases. Since most weak decay diagrams have quark lines where each has a definite flavor label, neutral mesons which are flavor mixtures are particularly interesting. Different diagrams can contribute to the different flavor components of the meson, and the wave function itself provides interference.

hep-ph↗