Leonard S. Kisslinger

The isobar-doorway theory for pion-nucleus interactions

Abstract Pion-nucleus scattering and reactions are treated in a theory which explicitly introduces the pion-nucleon resonances. Using a separation in Hilbert Space, doorway states of isobar-nuclear systems are introduced and nonresonant processes are clearly separated from resonance interactions. With one choice of doorway states a multiple scattering series is derived which corresponds to the conventional theory with binding energy and other corrections included. When another choice the isobar-doorway model is derived, with parameterization explicitly related to specific dynamic effects, our framework provides a phenomenological model for treating meson-nucleus interactions to all orders. Moreover, the parameters of the model have clear theoretical significance which can extend our knowledge of strong interactions physics. A numerical study is given for elastic scattering.

UPSILON PRODUCTION IN pp COLLISIONS AT LHC

This is a continuation of recent studies of ϒ(nS) production at the LHC in pp collisions. Our previous studies were for 2.76 TeV, while the present predictions are for 7.0 TeV collisions.

A coupled-channel treatment of baryon resonances in nuclei☆

Abstract A coupled-channel treatment of the two-baryon system is carried out in order to study the effects of baryon-resonance components in nuclear states. The coupling potentials are derived in a static one-pion-exchange model, and a one-boson-exchange interaction is used in the two-nucleon channel. For the deuteron, the wave function of the Δ(1236)-Δ(1236) component is calculated and found to have high Fourier components. For N-N scattering the Δ(1236) components are shown to account for much of the intermediate range attraction for which scalar mesons are introduced in one-boson-exchange models.

Mixed scalar glueballs and mesons

Abstract We find QCD sum rule solutions for scalar meson-glueball mixed states consistent with the f0(1500) being largely a glueball and the f0(1370) being a largely meson state, consistent with recent experiments. Pure scalar glueball solutions are in the 300–600 MeV region and pure 0 ++ q q meson solutions are found near 1 GeV.

The weak parity-violating pion-nucleon coupling

Abstract We use QCD sum rules to obtain the weak parity-violating pion-nucleon coupling constant f πNN . We find that f πNN ≈ 2 × 10 −8 , about an order of magnitude smaller than the “best estimates” based on quark models. This result follows from the cancellation between pertubative and nonperturbative QCD processes not found in quark models, but explicit in the QCD sum rule method. Our result is consistent with the experimental upper limit found from 18 F parity-violating measurements.

Skewed quark distribution of the pion in the light front quark model

We calculate the skewed quark distributions(SQDs) of the pion in the light-front quark model, and discuss the calculation of the nonvalence contribution to the SQDs in this model. The frame-independence of our model calculation is guaranteed by the constraint of the sum rule between the SQDs and form factor. Our numerical results show large nonvalence contributions to the SQDs at small momentum transfer region as the skewedness increases.

The 3He charge form factor in the hybrid model

Abstract Electron scattering by nucleons plus six-quark contributions can explain F ch ( 3 He ) for q ≲1 GeV/ c . At higher momentum transfer, q ≲1.5 GeV/ c , nine-quark processes dominate, possibly taking one to the region where perturbative QCD can be tested at q ≳2 GeV/ c .

Gravitational Radiation Generated by Cosmological Phase Transition Magnetic Fields

We study gravitational waves generated by the cosmological magnetic fields induced via bubble collisions during the electroweak (EW) and QCD phase transitions. The magnetic field generation mechanisms considered here are based on the use of the fundamental EW minimal supersymmetric and QCD Lagrangians. The gravitational waves spectrum is computed using a magnetohydrodynamic turbulence model. We find that the gravitational wave spectrum amplitude generated by the EW phase transition peaks at a frequency of approximately 1-2 mHz, and is of the order of 10{sup -20}-10{sup -21}; thus this signal is possibly detectable by the Laser Interferometer Space Antenna (LISA). The gravitational waves generated during the QCD phase transition, however, are outside the LISA sensitivity bands.

TIME REVERSAL IN NEUTRINO OSCILLATIONS IN MATTER

We estimate the time reversal violations for neutrino oscillations in matter for typical experimental energies and baselines. We examine the present status of experiments on neutrino oscillations, propose experiments for TRV, and discuss the future.

Continuity of generalized parton distributions for the pion virtual Compton scattering

We discuss a consistent treatment of the light-front gauge-boson and meson wave functions in the analyses of the generalized parton distributions(GPDs) and the scattering amplitudes in deeply virtual Compton scattering(DVCS) for the pion. The continuity of the GPDs at the crossover, where the longitudinal momentum fraction of the probed quark is same with the skewedness parameter, and the finiteness of the DVCS amplitude are ensured if the same light-front radial wave function as that of the meson bound state wave function is used for the gauge boson bound state arising from the pair-creation(or nonvalence) diagram. The frame-independence of our model calculation is also guaranteed by the constraint from the sum rule between the GPDs and the form factors.