R. E. Marshak

Conceptual foundations of modern particle physics

Genesis and overview of modern particle physics space-time symmetries in quantum field theory global internal symmetries and their spontaneous breakdown gauge symmetry groups and their spontaneous breakdown gauge theory of the strong interaction (QCD) gauge theory of the electroweak interaction (QFD) chiral anomalies on the standard model and beyond unification of the strong and electroweak interactions fermion generation problems and preon models topological conservation laws.

THE RADIATIVE AND CONDUCTIVE OPACITIES UNDER WHITE DWARF CONDITIONS

TXE CALCULATION OF THE RADIATIVE OPACITY In order to investigate the state of matter in the interior of a white dwarf star, and in particular to determine the temperature distribution, it is necessary to derive fairly accurate expressions for the radiative and conductive opacities in both the region of incipient degeneracy and in the region of strong degeneracy. In this pa,per such expressions are derived arid put in a form suitable for use in white dwarf calculations. If a, is the mass absorption coefficient corresponding to radiation of frequency Y, the radiative opacity K s is defined as the “Rosseland” mean of this quantity, namely:

Photodisintegration of the deuteron in the medium energy range

Abstract The photodisintegration of the deuteron is calculated for γ-ray energies in the laboratory from 9.23 MeV to 152.4 MeV. Special attention is given to the range Eγ = = 9.23 MeV to Eγ = 77.3 MeV corresponding to nucleon-nucleon scattering in the laboratory from 14 MeV to 150 MeV. As nucleon-nucleon interaction we use the SM1 potential and for the deuteron we use the Gartenhaus deuteron with 6.7% D state. Calculated is the total cross section, angular distribution for unpolarized as well as polarized γ-rays and the polarization of outgoing nucleons for unpolarized γ-rays. Where possible a comparison with the experiments is made. It is shown that the photodisintegration can impose conditions on the phase shift sets that will allow us to rule out several of the proposed phase shift sets at 150 MeV nucleon-nucleon scattering.

Effect of the spin-orbit potential on the magnetic moment of the deuteron

SummaryIt is shown that at the present stage the contribution to the magnetic moment of the deuteron does not pose a serious dilemma for the spin-orbit potential explanation (in addition to the Gartenhaus potential) of the high energy nucleon-nucleon scattering (up to 150 MeV).RiassuntoSi dimostra che attualmente il contributo al momento magnetico del deutone non pone un serio dilemma alla spiegazione del Potenziale spin-orbita (in aggiunta al potenziale Gartenhaus) dello scattering nucleone-nucleone ad alta energia (fino a 150 MeV).

The triality quantum number inSU3 andU3 symmetry and its application to weak interactions

Summary— The definition of the triality quantum number in both theSU3 andU3 groups is investigated in connection with the problem of fractionally charged particles. It is shown that in order to describe a triplet of particles having integral values of charge and hypercharge it is necessary and sufficient to use the group U3 rather than the groupSU3. Finally as an application we investigate the possibility that leptons may belong to unitary triplets in weak interactions.RiassuntoSi studia la deflnizione del numero quantico della trialità nei due gruppi SU3 eU3, in relazione al problema delle particelle con carica frazionaria. Si dimostra che allo scopo di descrivere un tripletto di particelle aventi valori interi della carica e dell’ipercarica è necessario e sufficiente usare il gruppo U3 invece del gruppoSU3. Infine, come applicazione, si studia la possibilità che i leptoni possano appartenere a tripletti unitari nelle interazioni deboli.

Effect of pion resonances on the (π+-π0) and (K+-K0) mass differences

SummaryThe electromagnetic form factor of pions and kaons, obtained on the basis of the experimentally observed pion and K-π resonances, are fed into the known dispersion-theoretic formula relating the mass difference to the form factors. It is observed that the (π+-π0) mass difference is completely explained on the basis of the 2π resonance at 750 MeV in theJ=1,T=1 state. The sign and magnitude of the (K+-K0) mass difference could be explained if one accepts corresponding restrictions on the isoscalar part of the kaon form factor.RiassuntoIl fattore di forma elettromagnetico dei pioni e kaoni, ottenuto sulla base delle risonanze del pione e K-π, osservate sperimentalmente, vengono introdotte nella nota formula della dispersione teorica che mette in relazione la differenza di massa con i fattori di forma. Si osserva che la differenza di massa (π+-π0) si spiega completamente sulla base della risonanza 2π di 760 MeV nello statoJ=1,T=1. Il segno e la grandezza della differenza di massa (K+-K0) potrebbero essere spiegati se si accettassero le corrispondenti restrizioni alla parte isoscalare del fattore di forma del kaone.

APS and the international physics community in 1983

World War II was a turning point in the fortunes of American science. The many scientific contributions to the winning of the war—radar, the proximity fuse, the atomic bomb—led a grateful nation to expand greatly its support of basic research at universities, from which the bulk of wartime researchers had come and to which they returned. Since physicists had played such a prominent role in the war effort, it was not surprising that physics was one of the chief beneficiaries of the new public policy. It is worth recalling that the first Federal agency to provide substantial funds for academic physics was the Office of Naval Research, which, among other things, provided the funds for the first high‐energy machines. By the early 1950s, the Atomic Energy Commission and the National Science Foundation were fully established and began to assume increasing responsibility for support of basic research in the physical sciences. After Sputnik in 1957, NASA joined NSF and AEC (now DOE) as one of three key civilian a...

R-INVARIANCES OF STRONG AND WEAK INTERACTIONS

SummaryThree alternative formulations of invariance under hypercharge (R) conjugation are considered. Some consequences of the three forms ofR-invariance are presented for weak interactions (both leptonic and nonleptonic) as well as for strong and electromagnetic interactions. Existing experimental data disfavor the standard form but are consistent with the other two forms ofR-invariance. Further experimental tests are needed to confirm the value of the new symmetry principle.RiassuntoSi considerano tre formulazioni alternative dell‘invarianza rispetto alla coniugazione dell‘ipercarica (R). Si presentano alcune conseguenze delle tre forme di invarianza rispetto aR per le interazioni deboli (sia leptoniche che non leptoniche) e per le interazioni forti ed elettromagnetiche. I dati sperimentali esistenti sono a sfavore della forma standard ed invece sono compatibili con le altre due forme di invarianza rispetto aR. Necessitano ulteriori verifiche sperimentali per confermare la validità del nuovo principio di simmetria.

Pole approximation for nonleptonic and radiative hyperon decays with odd Σ-Λ relative parity

SummaryThe pole approximation for the non-leptonic decay modes of the hyperon is examined on the basis of odd Σ-Λ relative parity. The same method is applied to the study of the radiative decay modes of the hyperon.RiassuntoSulla base della parità relativa dispari Σ-Λ, si esamina l’approssimazione polare per i modi di decadimento non leptonico dell’iperone. Lo stesso metodo viene applicato allo studio dei modi di decadimento radiativo dell’iperone.

Remarks on the possible existence of a neutral muon

SummaryThe arguments for and against the existence of a neutral muon are discussed. The weak interactions in which a neutral muon might replace the neutrino are enumerated. It is concluded that the most favorable experimental circumstances, for the detection of the neutral muon would obtain if one searches for the reaction K+→μ++μ0.RiassuntoSi discutono gli argomenti pro e contro l’esistenza di un muone neutro. Si enumerano le interazioni deboli in oui un muone neutro potrebbe sostituire il neutrino. Si conclude che le più favorevoli condizioni sperimentali per la rivelazione del muone neutro si otterrebbero ricercando la reazione K+→[μ++μ0.