Chandana P. Jayalath

Strong and electromagnetic mass splittings in heavy mesons

The contributions to heavy meson mass differences by the strong hyperfine interaction, the light quark masses and the electromagnetic interaction are obtained from the empirical values of the D, D*, B and B* masses by means of a mass formula based on the heavy quark mass expansion. The three different types of contributions are determined with significant accuracy to next to leading order in that expansion.

Negative parity baryon decays in the 1/Nc expansion

C. Jayalath a,b,c , J. L. Goity a,b , E. González de Urreta d,e , N. N. Scoccola d,e,f Department of Physics, Hampton University, Hampton, VA 23668, USA. Thomas Jefferson National Accelerator Facility, Newport News, VA 23606, USA. Department of Physics, Peradeniya University, Peradeniya 20400, Sri Lanka. Department of Theoretical Physics, Comisión Nacional de Enerǵıa Atómica, 1429 Buenos Aires, Argentina. CONICET, Rivadavia 1917, 1033 Buenos Aires, Argentina. Universidad Favaloro, Soĺıs 453, 1078 Buenos Aires, Argentina. Abstract The partial decay widths of lowest lying negative parity baryons belonging to the 70-plet of SU(6) are analyzed in the framework of the 1/Nc expansion. The channels considered are those with single pseudoscalar meson emission. The analysis is carried out to sub-leading order in 1/Nc and to first order in SU(3) symmetry breaking. Conclusions about the magnitude of SU(3) breaking effects along with predictions for some unknown or poorly determined partial decay widths of known resonances are obtained.

Analysis of 56-plet Positive Parity Baryon Decays in the 1/Nc Expansion

The partial decay widths of positive parity baryons belonging to 56-plets of SU(6) are analyzed in the framework of the 1/Nc expansion. The channels considered are those with emission of a single pion, K or K-bar mesons, and the analysis is carried out to subleading order in 1/Nc and to first order in SU(3) symmetry breaking. The results for the multiplet [56,0+], to which the Roper resonance belongs, indicate a poor description at leading order, requiring large next to leading order corrections. For the multiplet [56,2+], the P-wave decays in the non-strange sector are well described at leading order and important SU(3) breaking corrections are necessary to describe transitions involving strangeness, on the other hand, the F-wave decays require the next to leading order corrections, which turn out to be however of natural magnitude.

Partial Decay Widths of Negative Parity Baryons in the 1/Nc Expansion

The partial decay widths of lowest lying negative parity baryons belonging to the 70-plet of SU(6) are analyzed in the framework of the 1/Nc expansion. The channels considered are those with single pseudoscalar meson emission. The analysis is carried out to sub-leading order in 1/Nc and to first order in SU(3) symmetry breaking. Conclusions about the magnitude of SU(3) breaking effects along with predictions for some unknown or poorly determined partial decay widths of known resonances are given.

The 1/N(c) expansion in baryons

The 1/N C expansion in baryons is discussed with two applications, namely baryon masses and partial decay widths. These applications provide the basic insights on the utility of the expansion.

Negative Parity Baryon Decays in the 1/Nc Expansion

The 1/Nc expansion of QCD provides a useful framework for phenomenological studies of both ground state and excited baryons. Here, we focus on its application to the excited baryon strong decays via emission of single pseudoscalar meson. The S‐ and D‐wave decay amplitudes of the negative parity baryons in the [70,1−] of SU (6) are analyzed to subleading order in 1/Nc and to first order in SU(3) symmetry breaking. In particular, the SU(3) symmetry breaking is studied in detail through SU(3) breaking decay operators and state mixing.

The 1/N{sub C} Expansion in Baryons

The 1/N C expansion in baryons is discussed with two applications, namely baryon masses and partial decay widths. These applications provide the basic insights on the utility of the expansion.

The 1/NCExpansion in Baryons

The 1/N C expansion in baryons is discussed with two applications, namely baryon masses and partial decay widths. These applications provide the basic insights on the utility of the expansion.

The 1/NC Expansion in Baryons

The 1/N C expansion in baryons is discussed with two applications, namely baryon masses and partial decay widths. These applications provide the basic insights on the utility of the expansion.