768 research outputs found
Current Algebras and Symmetries in Bootstrap Theory
In the first paper of this series we showed how, in the bootstrap theory, the currents associated with the
hadrons could be determined from a set of self-consistency conditions. In the present paper we show that
these "self-consistent" currents satisfy a current algebra. The proof is accomplished without recourse to any
approximate model It includes the interesting case of nonconserved currents. The convergence of sum rules
derived from current algebras is investigated in detail, and shown to be most rapid when no "nonbootstrap"
terms are present. Using these convergence properties, we discuss how and when current algebras can give
rise to hadron symmetries
General S-Matrix Methods for Calculation of Perturbations on the Strong Interactions
Recently, the authors proposed an on-the-mass-shell, S-matrix method for computing the effects of small perturbations on the masses and coupling constants of strongly interacting particles. In the present paper, the method is generalized to the multichannel case. The use of group-theoretical techniques in reducing the complexity of the method is described in detail
Vanya and Sonia and Masha and Spike Senior Project by Lauren Frautschi
This is a description of my acting process throughout my senior project production. I played Masha in Vanya and Sonia and Masha and Spike, and documented my discoveries and education along the way
Self-Consistent Determination of Coupling Shifts in Broken SU(3)
The possibility that certain patterns of SU(3) symmetry breaking are dynamically enhanced in baryon-meson couplings is studied by bootstrap methods. For the strong couplings, a single dominant enhancement is found. It produces very large symmetry-breaking terms, transforming like an octet, as often conjectured. Experimental consequences are listed, such as a reduction of K-baryon couplings relative to π-baryon couplings which is in accord with the experimental weakness of K relative to π production in many circumstances, such as photoproduction and multi-BeV cosmic-ray collisions. For parity-violating nonleptonic couplings, a dominant octet enhancement is again found, as mentioned in a previous paper, which leads to an excellent fit with experiment. For parity-conserving nonleptonic couplings, on the other hand, several different enhancements compete, and the only conclusion we can draw is that terms with the "abnormal" transformation properties brought in by strong symmetry-breaking corrections are present. Our work provides a dynamical derivation of various phenomenological facts associated with SU(6), such as the dominance of the 35 representation in parity-violating nonleptonic decays
Measuring Hadronization Length in e^+ e^- \rightarrow K^0 {\bar{K}}^0 \gamma
We propose to study the space-time picture of hadronization by looking at the
angular distribution of photons emitted in the process e^+ e^- \rightarrow K^0
{\bar{K}}^0 \gamma at DA{\Phi}NE energies. it is shown that the angular
distributions are quite sensitive to the hadronization length.Comment: 5 pages, CERN-TH-7200/94, BI-TP 94/04, March 199
Reggeization of Pion Exchange in Production Processes
Couplings of the pion Regge trajectory are discussed. We find that the kinematic factors prescribed by Wang must be supplemented by further kinematic terms. A simple physical interpretation is given for these additional terms. Our considerations lead to a model of pion trajectory couplings, which is in reasonable agreement with those experiments on vector- and tensor-meson production in which pion exchange is expected to dominate the forward peak
Equation of State in a Strongly Interacting Relativistic System
We study the evolution of the equation of state of a strongly interacting
quark system as a function of the diquark interaction strength. We show that
for the system to avoid collapsing into a pressureless Boson gas at
sufficiently strong diquark coupling strength, the diquark-diquark repulsion
has to be self-consistently taken into account. In particular, we find that the
tendency at zero temperature of the strongly interacting diquark gas to
condense into the system ground state is compensated by the repulsion between
diquarks if the diquark-diquark coupling constant is higher than a critical
value . Considering such diquark-diquark repulsion, a positive
pressure with no significant variation along the whole strongly interacting
region is obtained. A consequence of the diquark-diquark repulsion is that the
system maintains its BCS character in the whole strongly interacting region.Comment: 9 pages, 7 figs, To appear in Phys. Rev.
Experimental Restrictions on Ne'eman's Fifth Interaction
Recently, Ne'eman has proposed a "fifth interaction" between the strangeness current and a neutral vector meson χ, for the purpose of breaking SU(3) symmetry. We show that a χ mass less than 2mπ would be inconsistent with a variety of experiments, including K-mesonic atoms, the long-range pp potential, K1 regeneration from a K2 beam, the Lamb shift, modern refinements of the Cavendish "ice-bucket" experiment, and the absence of π0→γ+χ and χ→e++e-. The remaining possibility, that mχ exceeds 2mπ, is discussed briefly
Determination of Asymptotic Parameters in the Statistical Bootstrap Model
The statistical bootstrap model predicts that the density of hadron states ρ(m) approaches cmaebm asymptotically. We consider the consequences of extending the bootstrap condition in the model from asymptotic down to finite masses. This allows us to determine the parameters a, b, and c for various assignments of the hadron volume and low-mass input spectrum, and for the extreme cases of excluding all exotic particles or including all of them. In all cases, a=-3 for ρtot (summed over all internal quantum numbers). The parameter b varies somewhat from case to case but is always of order mπ^-1; thus we predict the maximum temperature T0=b^-1≈mπ in rough agreement with Hagedorn's empirical determination. The inclusion of exotic states has little effect on ρtot but does redistribute the partial level densities according to a simple rule. The predicted level densities (excluding exotic states) are compared with present data
Dynamical Theory for Strong Interactions at Low Momentum Transfers but Arbitrary Energies
Starting from the Mandelstam representation, it is argued on physical grounds that "strips" along the boundaries of the double spectral regions are likely to control the physical elastic scattering amplitude for arbitrarily high energies at small momentum transfers. Pion-pion scattering is used as an illustration to show how the double spectral functions in the nearest strip regions may be calculated, and an attempt is made to formulate an approximate but "complete" set of dynamical equations. The asymptotic behavior of the solutions of these equations is discussed, and it is shown that if the total cross section is to approach a constant at large energies then at low energy the S-dominant ππ solution is inadmissible. A principle of "maximum strength" for strong interactions is proposed, and it is argued that such a principle will allow large low-energy phase shifts only for l<~lmax, where lmax~1
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