Golowich, Eugene
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Professor Emeritus, Department of Physics
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Golowich
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Eugene
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Physics
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Publication 2-BODY DECAYS OF THE NUCLEON(1980) Golowich, EWe compute branching ratios for proton and neutron decay for SU(5), SO(10), and SU(2)L×SU(2)R×U(1) unification schemes. Quark wave functions from the MIT bag model are used to describe hadron structure. The results differ from those of nonrelativistic SU(6). The proton and neutron total lifetimes are also estimated.Publication Dimension-eight operators in the weak OPE(2000-01-01) Cirigliano, V; Donoghue, JF; Golowich, EugeneWe argue that there is a potential flaw in the standard treatment of weak decay amplitudes, including that of ǫ′/ǫ. We show that (contrary to conventional wisdom) dimension-eight operators do contribute to weak amplitudes, at order GFαs and without 1/M2W suppression. We demonstrate the existence of these operators through the use of a simple weak hamiltonian. Their contribution appears in different places depending on which scheme is adopted in performing the OPE. If one performs a complete separation of short and long distance physics within a cutoff scheme, dimension-eight operators occur in the weak hamiltonian at order GFαs/μ2, μ being the separating scale. However, in an MS renormalization scheme for the OPE the dimension-eight operators do not appear explicitly in the hamiltonian at order GFαs. In this case, matrix elements must include physics above the scale μ, and it is here that dimension eight effects enter. The use of a cutoff scheme (especially quark model methods) for the calculation of the matrix elements of dimension-six operators is inconsistent with MS unless there is careful matching including dimension-eight operators. The contribution of dimension-eight operators can be minimized by working at large enough values of the scale μ. We find from sum rule methods that the contribution of dimension-eight operators to the dimension-six operator Q(6) 7 is at the 100% level for μ = 1.5 GeV. This suggests that presently available values of μ are too low to justify the neglect of these effects. Finally, we display the dimension-eight operators which appear within the Standard Model at one loop.Publication WEAK DECAY CONSTANTS OF HEAVY MESONS(1980) Golowich, EThe weak decay constant for a hadron of arbitrary mass is computed. The leptonic decays of the charmed D±, F± mesons are then discussed.Publication Charm Mixing and CP-violations - Theory(2008-01-01) Golowich, EugeneI begin by commenting on the most recent experimental compilation of D^0 mixing data, emphasizing the so-called 'strong phase' issue. This is followed by a review of the theory underlying charm mixing, both Standard Model and New Physics. The mechanism of R_p-violation is used to illustrate the methodology for New Physics contributions and the relation of this to rare D^0 decays is pointed out. Finally, I address the subject of CP-violating asymmetries by describing some suggestions for future experimental studies and a recent theoretical analysis of New Physics contributions.Publication Unbinding the Deuteron(2008-01-01) Golowich, EugeneWe consider a description of the deuteron based on meson exchange potentials. A key feature is the inclusion of the I=S=0 two-pion intermediate state ('sigma(600)') as a significant component of the inter-nucleon potential energy. In this approach, deuteron binding is seen to be predominantly a consequence of sigma(600) and omega(783) exchange, with a secondary tole played by rho(770). We explore sensitivity of two-nucleon binding to changes in the potential and thereby obtain an anthropic constraint -- that the deuteron unbinds for a modest decrease (about 6%) in the attractive sigma(600) potential.Publication The chiral limit K -> pi pi matrix elements of the electroweak penguin operators Q(7,8)(2003-01-01) Maltman, K; Cirigliano, V; Donoghue, JF; Golowich, EugeneThe SU(3) chiral limit K → ππ matrix elements of the electroweak penguin operators, Q7,8, are determined using hadronic τ decay data, and dispersive and finite energy sum rules.Publication Analysis of O(p2) corrections to 〈ππ|Q7,8|K〉(2000-01-01) Cirigliano, V; Golowich, EThe one-loop corrections to K→π and K→2π matrix elements of the electroweak penguin operator are calculated. General next-to-leading order relations between the K→π and K→2π amplitudes are obtained. The fractional shift Δ2=0.27±0.27 is found for the Image corrections to a recent chiral determination of Image . We explain why the sign for Δ2 is opposite to that expected from unitarization approaches based on the Omnès equation. We perform a background-field, heat-kernel determination of the divergent one-loop amplitudes for a general class of (V−A)×(V+A) operators.Publication Dispersive calculation of B-7((3/2)) and B-8((3/2)) in the chiral limit(2000-01-01) Donoghue, JF; Golowich, EugeneWe show how the isospin vector and axialvector current spectral functions V,3 and A,3 can be used to determine in leading chiral order the low energy constants B(3/2) 7 and B(3/2) 8 . This is accomplished by matching the Operator Product Expansion to the dispersive analysis of vacuum polarization functions. The data for the evaluation of these dispersive integrals has been recently enhanced by the ALEPH measurement of spectral functions in tau decay, and we update our previous phenomenological determination. Our calculation yields in the NDR renormalization scheme and at renormalization scale μ = 2 GeV the values B(3/2) 7 = 0.55±0.07±0.10 and B(3/2) 8 = 1.11±0.16±0.23 for the quark mass values ms + ˆm = 0.1 GeV.Publication Comment on ‘Analysis of O(p2) Corrections to hðð|Q7,8|Ki’(2002-01-01) Cirigliano, Vincenzo; Golowich, EugeneWe extend in several respects our earlier work on O(p2) corrections to the matrix elements of the electroweak penguin operator Oewp. First, to facilitate comparison with certain lattice studies we calculate O(p2) corrections to 〈π|Oewp|K〉 in the SU(3) limit of equal light quark masses. Next, we demonstrate how an apparent disagreement in the literature regarding whether higher order chiral contributions increase or decrease 〈(ππ)I=2|Oewp|K〉 is simply a consequence of how the leading order chiral amplitude is defined. Finally, we address an aspect of the ε′/ε problem by estimating O(p2) corrections to recent determinations of 〈(ππ)I=2|Q7,8|K〉 which were carried out in the chiral limit.Publication Can nearby resonances enhance D-0-(D)over-bar(0) mixing?(1998) Golowich, E; Petrov, AAWe study the contributions of resonances to mixing. Both and hybrid states are considered. Assuming reasonable values for the resonance parameters, we find relatively sizeable individual contributions to both ΔmD and ΔΓD. We derive a variant of the GIM cancellation mechanism for the resonance amplitudes and show that broken SU(3) can allow for appreciable residual effects. Additional input from meson spectroscopy and lattice gauge simulations will be needed to improve the accuracy of these predictions.