相关论文: Remarks on the Delta(+) mass
The pion mass difference generates a pronounced cusp in the pi0 pi0 invariant mass distribution of K+ --> pi0 pi0 pi+ decays. As originally pointed out by Cabibbo, an accurate measurement of the cusp may allow one to pin down the S-wave…
We review the current status of the neutrino mass and mixing parameters needed to reconstruct the neutrino mass matrix. A comparative study of the precision in the measurement of oscillation parameters expected from the next generation…
The production of the isoscalar Jp = 3+ didelta dibaryon d* by proton inelastic scattering from deuteron targets is described in a double-scattering Glauber approximation. Each scattering changes a target nucleon into a Delta with the help…
Incoherent $\pi^0$ photoproduction on a deuteron in the $\Delta(1232)$ region is treated in a three-body scattering approach using separable two-body interactions. Results are presented for total and differential cross sections. It turns…
We investigate the errors due to the use of unphysical values of light quark masses in lattice extractions of $\alpha_s$. A functional form for the pion mass dependence of the quarkonium mass splittings ($\Delta m$) is given as an expansion…
It is shown that theories already presented as rigorous mathematical formalizations of widespread manipulations of Dirac's delta function are all unsatisfactory, and a new alternative is proposed.
Data on pion polarizabilities obtained in different experiments are reviewed. The values of the dipole and quadrupole polarizabilities of the pi^0 and pi^{+-} mesons found are compared with predictions of dispersion sum rules (DSRs) and…
The neutrino pion production off the nucleon is traditionally described in the literature by means of the weak excitation of the Delta(1232) resonance and its subsequent decay into N pi. Here, we present results from a model that includes…
The feasibility of determining $\Delta \Gamma_s / Gamma_s$ from $B_s \to D_s^{(*)+} D_s^{(*)-}$ decay branching fraction measurements at $e^+ e^-$ colliders running on the $\Upsilon$(5S) resonance is discussed. The expected accuracies of…
Recently a strong indication for a deviation from the standard model (SM) has been obtained by PIBETA Collaboration. Namely, SM fails to describe the energy distribution and the branching ratio of the radiative decays of the positive pions…
Several methods for the treatment of pion photoproduction in the region of the Delta(1232) resonance are discussed, in particular the effective Lagrangian approach and the speed plot analysis are compared to a dynamical treatment. As a main…
We report new precision p(e,e' pi+})n measurements in the Delta(1232) resonance at Q2 = 0.127(GeV/c)2 obtained at the MIT-Bates Out-Of-Plane scattering facility. These are the lowest, but non-zero, Q2 measurements in the pi+ channel. The…
We predict the formation of highly dense baryon-rich resonance matter in Au+Au collisions at AGS energies. The final pion yields show observable signs for resonance matter. The Delta(1232) resonance is predicted to be the dominant source…
The problem of nucleon resonances N' with masses below the Delta is considered. We derive bounds for the properties of such states. Some of these are new, while others improve upon existing limits. We discuss the nature of N' states, and…
Standards calculations by the Fermi's Golden rule involve approximations. These approximations could lead to deviations from the predictions of the standard model as discussed in another paper. In this paper we propose experimental searches…
We compare results for the D13(1520) photon-decay amplitudes determined in analyses of eta- and pion-photoproduction data. The ratio of helicity amplitudes (A_3/2 / A_1/2), determined from eta-photoproduction data, is quite different from…
Our present information on the gluon polarisation Delta g/g is reviewed. The data from fixed-target lepton-nucleon experiments are in context with the recent data from the RHIC polarised pp collider. The main tools to study Delta g/g in…
This paper, together with a subsequent paper, questions the so-called 'LSND anomaly': a 3.8 {\sigma} excess of anti-electronneutrino interactions over standard backgrounds, observed by the LSND Collaboration in a beam dump experiment with…
Low-energy Compton scattering off the proton is used for determination of the proton polarizabilities. However, the present empirical determinations rely heavily on the theoretical description(s) of the experimental cross sections in terms…
A general expression for the $\pi -N$ and $\pi-\Delta $ scattering lengths is derived in the framework of a microscopic calculation. Annihilation, negative energy wave-functions and spontaneous chiral symmetry are included consistently. The…