Simple method for estimating shape functions of optical spectra

A simple method for estimating shape functions of optical spectra is proposed, based on the numerical correlation with an assumed optical spectrum composed of a central main rectangular component and two right-angled triangular wings on either side of the main component. The degrees of correlation between observed and assumed spectra were examined using spectral and coherence widths of those spectra and pulsewidths of Fourier-transform-limited pulses calculated from those spectra. By using this method, shape functions of output spectra from superluminescent diodes and a self-pulsating laser diode were evaluated in detail over a relatively wide injection current range beyond their rated currents.     

Dual properties of inclusive spectra

The dual properties of the inclusive reaction π^?p → pX are studied over a wide energy range by exploiting the scaling behaviour. Semi-local duality is found to be well satisfied. An energy-dependent triple-Regge analysis reveals a strong triple-pomeron coupling. There is some evidence of an abnormal component in which diffractively produced resonances are dual to pomeron exchange. Combining duality with factorization leads to relations between production cross sections of meson and baryon resonances in πp and pp collisions, which are compatible with existing experimental data.     

The inclusive semileptonic B decay lepton spectrum from $$ B \to Xe\bar v$$

In this talk, we review the QCD calculations of the lepton spectrum from inclusive semileptonicB decay. We compare this prediction to that of the ACCMM model. This latter work was done in collaboration with Csaba Csaki.     

Bounds on multiplicity distributions from one-particle inclusive spectra

Using energy conservation sum rules, we derive bounds on multiplicity distributions in terms of one-particle inclusive spectra.     

Relations between inclusive decay rates of heavy baryons

The dependence of inclusive weak decay rates of heavy hadrons on the flavors of spectator light quarks is revisited with application to decays of charmed and b hyperons. It is pointed out that the differences in the semileptonic decay rates, the differences in the Cabibbo-suppressed decay rates of the charmed hyperons, and the splitting of the total decay rates of the b hyperons are all related to the differences in the lifetimes of the charmed hyperons independently of poor knowledge of hadronic matrix elements. The approximations used in these relations are the applicability of the expansion in the inverse of the charmed quark mass and the flavor SU(3) symmetry.     

Measurement of inclusive neutron spectra at the ISR

With a total absorption counter, inclusive neutron spectra have been measured at four ISR energies and at angles of 20, 66 and 119 mrad. The spectra show scaling behavior in the variables x and p⊥. Pion exchange is found to be important at large x values.     

Statistical bootstrap of fireball decay spectra

We propose a generalized statistical bootstrap equation for the generating functional of the fireball decay spectra which includes the bootstrap of the hadronic mass spectrum. In the form of an integral representation a solution is given for some n-particle distributions as well as multiplicity moments in the case of identical particles. Within this formalism we are able to discuss decay-chain end effects and to treat quantum number conservation explicity. The general equation is approximated by a simpler bootstrap equation for the linear decay chain with quantum-number conservation. An asymptotic solution for the single particle distributions according to this equation is discussed.     

Regge phenomenology of inclusive spectra in the central region

In the light of new data from the ISR, initial steps are taken towards the Regge analysis of inclusive spectra in the central region. It is shown that some features in the data necessitate the introduction of a further singularity in addition to the Pomeron and the meson trajectories ? - f - ω - A₂. The resulting model yields many predictions via duality and factorisation which can easily be tested at ISR and Batavia energies.     

Rise of proton proton total cross section and inclusive spectra

The origin of the rise of p-p total cross section (σ_t(pp)) is investigated by making use of the inclusive sum rule. The contribution to the rise of σ_t(pp) from the development of sharp peak near the kinematical boundary in the process p+p→p+ “anything” is almost completely canceled out by the decrease of the cross section in other x-region between s=45 (GeV/c)² and s=2820 (GeV/c)². Then the net contribution to the rise of σ_t(pp) from the process p+p→p+ “anything” is very likely to be zero. The true origin of the rise of σ_t(pp) is found to be the increase of inclusive cross sections at x ? 0 between PS and ISR energies. The contribution from the process p+p→π+ “anything” at x ? 0 to the rise of σ_t(pp) is estimated to be 3.2 mb, that from the process p+p→K + “anything”, 0.71 mb and that from the process p+p→$\text{p}$ “anything”, 0.62 mb. According to our conclusion we expect that all total cross sections will rise with energy at high energy.     

Residual Bose-Einstein correlations in inclusiveπ + π − systems and theρ(770)0 line shape in multihadronicZ 0 decay

It is shown that in jet-like particle systems with multiplicities typical of multihadronicZ ⁰ decay, Bose-Einstein correlations acting between identical pions may have significant indirect effects on the phase space for pairs of non-identical pions. These effects have a direct bearing on experimental studies of Bose-Einstein correlations, particularly with regard to the use ofπ ⁺ π ^? distributions as reference samples. In addition they may distort the line shape of the broad ρ(770)⁰ resonance decaying viaπ ⁺ π ^?. The observed line shape of theρ ⁰ depends on the details of the production and decay amplitudes, and the shape ofπ ⁺ π ^? mass spectra in theρ ⁰ mass region may be affected by a number of other phenomena includingρ ⁰?ω interference and interference with coherentπ ⁺ π ^? backgrounds. Various models are discussed, with particular emphasis on studies of inclusive ρ(770)⁰ production inZ ⁰ decays at LEP.     

Unusual line shape of B 1s core level spectra in rare earth hexaborides

We investigate the B 1s core level spectra of hexaborides, (, Ce, Pr, Nd), using high resolution X-ray photoemission spectroscopy. While all the B sites are identical, the experimental spectra exhibit a signature of multiple features manifested as an unusual asymmetry in the lower binding energy side. The analysis of the spectra reveals that the surface and bulk photoemission signals are different. In addition, the peak position shifts towards lower binding energies with the increase in 4f binding energy of the rare earth elements that can be attributed to the chemical potential shift due to lower degree of 4f-conduction electron hybridization. Decrease in temperature leads to a narrowing of the linewidth in every case. The Kondo systems exhibit more prominent narrowing of the B 1s linewidth.     

Features of multiplicity distributions in a bootstrap model of inclusive spectra

Using a bootstrap model of inclusive spectra we derive an integral equation satisfied by the generating function for multiplicity distributions. The (semi-asymptotic) solution of this equations has the form Ψ(λ, s) = Ψ(λ, s₀)(s/s₀)^b(λ) where s is the usual energy variable and b(λ) satisfies an eigenvalue equation and is completely determined by the leading particle distribution. Closed formulae for the binomial moments and for correlation coefficients are also given, and in addition we discuss some general features of the bootstrap model. As a phenomenological application we discuss the rate of variation with energy of multiplicity moments. Our results are expected to be representative for multiperipheral-like models.     

Contributions of exclusive pion electroproduction reactions to inclusive structure functions

The contributions of exclusive π⁺n, π⁰p, and π^?π⁺p channels to the inclusive structure function F ₂(x, Q ²) are determined from the CLAS collaboration data analysis. Reliability of the CLAS data on the inclusive structure function and single-pion electroproduction channels is verified. The total contribution of the uninvestigated π⁺π⁰n and π⁰p channels to this function and the integrated cross sections of these channels at photon virtualities Q ² = 0.4 and 0.5 GeV² are predicted.     

On the exponential decay of correlation functions

We use the properties of subharmonic functions to prove the following results, First, for any lattice system with finite-range forces there is a gap in the spectrum of the transfer matrix, which persists in the thermodynamic limit, if the fugacityz lies in a regionE of the complex plane that contains the origin and is free of zeros of the grand partition function (with periodic boundary conditions) as the thermodynamic limit is approached. Secondly, if the transfer matrix is symmetric (for example, with nearest and next-nearest neighbor interactions in two dimensions), and if infinite-volume Ursell functions exist that are independent of the order in which the various sides of the periodicity box tend to infinity, then these Ursell functions decay exponentially with distance for all positivez inE. (For the Ising ferromagnet with two-body interactions, exponential decay holds forz inE even if the range of interaction is not restricted to one lattice spacing). Thirdly, if the interaction potential decays moreslowly than any decaying exponential, then so do all the infinite-volume Ursell functions, for almost all sufficiently small fugacities in the case of general lattice systems, and for all real magnetic fields in the case of Ising ferromagnets.     

Regularity and decay of lattice Green's functions

In the paper we study a class of lattice, covariant Laplace operators with external gauge fields. We prove that these operators are positive and that their Green's functions decay exponentially. They also have regularity properties similar to continuous space Green's functions. All the bounds are uniform in the lattice spacing.