33 Matching Results

Search Results

Advanced search parameters have been applied.

Resonances in high-energy colliding lepton beams

Description: The search for the correct higher symmetry of decay vertices is discussed. It is noted that something higher than SU(3) is certainly valid and colliding lepton beams can help find what it is. SU(6(/sub W/ and its limitations, L = 1, 2 mesons, and the two-photon processes e/sup +/ + e/sup -/ yields e/sup +/ + e/sup -/ + hadrons, and e/sup -/ + e/sup -/ yields e/sup -/ + e/sup -/ + hadrons are considered. (JFP)
Date: March 13, 1973
Creator: Rosner, J.L.
Partner: UNT Libraries Government Documents Department

Charmed particle lifetimes. [Review, six quark model]

Description: Conventional estimates are reviewed for charmed particle lifetimes. Free-quark models give values of (a few) x 10/sup -13/ sec to (a few) x 10/sup -12/ sec. The shorter of these values also follows from an extrapolation based on D ..-->.. Ke/sup nu/. Possible differences among the lifetimes and production rates of D/sup 0/, D/sup +/, F/sup +/, C/sub 0//sup +/, the heavy lepton tau, and the fifth quark b are discussed. Extreme values of mixing angles in a six-quark model could extend charmed particle lifetimes by a factor of at most three from the above estimates, while shorter lifetimes than those predicted could occur for some species like D/sup 0/ or F/sup +/ if their nonleptonic decays were enhanced. The predictions are discussed in the light of some current experimental results, and it is estimated that sigma(pp ..-->.. charm) approx. = 10 ..mu..b at 400 GeV/c. 95 references.
Date: January 1, 1979
Creator: Rosner, J.L.
Partner: UNT Libraries Government Documents Department

Heavy quarks and new particles

Description: Some aspects of particles containing c, b, and heavier quarks are reviewed. It is shown how these particles can provide tests of the short-range nature of the strong interactions, and how elementary quantum mechanics can reveal the color and charge of the constituents and the number of states below flavor threshold. Some new results are presented on the inverse problem for confining potentials. Properties of flavored hadrons (masses and lifetimes), of gluonic bound states, and of particles containing very heavy objects are also discussed.
Date: January 1, 1979
Creator: Rosner, J.L.
Partner: UNT Libraries Government Documents Department

Final states in charmed particle decays

Description: It is shown how weak decays of charmed particles provide information on the isospin properties of the charm-changing weak interactions, multi-particle production, enhancement of nonleptonic weak interactions, unseen decay modes of known charmed particles and best ways in which to discover new ones, and possible new weak currents and new fermions.
Date: January 1, 1977
Creator: Rosner, J. L.
Partner: UNT Libraries Government Documents Department

Improved lower limits on neutral fermion masses

Description: Present lower limits on the mass of a neutral fermion N coupled with full strength to an electron via the right-handed weak current are set only by the absence of the decay K/sup +/ ..-->.. Ne/sup +/: m(N) approximately greater than 0.5 GeV/c/sup 2/. It is shown that searches for the decays tau ..-->.. ..nu../sub tau/Ne or F ..-->.. Ne, followed by N ..-->.. e..pi.., can raise the lower bound on m(N) to well over 1 GeV/c/sup 2/ if no signal is seen in present or soon-to-be-acquired data. Estimates for the branching ratios for these processes are given. If N couples to e cos phi + ..mu.. sin phi with full strength, reference to phi may be eliminated by summing over e and ..mu.. in all final states.
Date: April 26, 1977
Creator: Rosner, J. L.
Partner: UNT Libraries Government Documents Department

Quantum mechanics with applications to quarkonium. [Review, WKB approximation, scale invariance]

Description: Some methods of nonrelativistic quantum mechanics which are particularly useful for studying the variation of bound-state parameters with constituent mass and excitation energy are reviewed. These techniques rely upon elementary scaling arguments and on the semiclassical (WKB) approximation. They are of general interest, but are applied here to the study of bound systems of a heavy quark and antiquark. Properties of the interquark interaction are extracted from information about masses and leptonic widths of the Psi and T families. It is shown how general methods can be applied to the determination of the electric charge of quarks and to the prediction of properties of new families. 113 references.
Date: February 1, 1979
Creator: Quigg, C. & Rosner, J.L.
Partner: UNT Libraries Government Documents Department

Isospin restrictions on charge distributions in charmed-particle decays. [Branching ratios]

Description: The isospin properties of the semileptonic and nonleptonic charm-changing weak interactions lead to restrictions on the branching ratios of the different charge states that can occur in multi-particle decays of charmed particles. Upper and lower bounds imposed by isospin invariance on these ratios, and on the average number of charged decay products, are calculated for various charmed-particle decay modes. Simultaneous bounds on the branching ratios of two different charge distributions in the same decay mode, or in isospin-related decay modes, are presented. Branching ratios are also calculated under the statistical postulate that all the allowed invariant isospin channels contribute equally and incoherently in each decay mode.
Date: January 1, 1976
Creator: Peshkin, M. & Rosner, J. L.
Partner: UNT Libraries Government Documents Department

Resonances decaying to a photon and a J(psi) particle

Description: If L = 1 orbital excitations /sup 3/P/sub 2/,/sub 1/,/sub 0/ of the J(psi) particle exist (assuming it to be a /sup 3/S/sub 1/ quark-antiquark state), the decays /sup 3/P/sub 2/,/sub 1/ ..-->.. J(psi) + ..gamma.., J(psi) ..-->.. (lepton)/sup +/ + (lepton)/sup -/ are predicted to yield W(/sup 3/P/sub 2/,theta) approximately 1 + (0.4 to 0.6) cos/sup 2/ theta and W(/sup 3/P/sub 1/,theta) approximately sin/sup 2/ theta. Here W(theta) is the distribution in angle theta between the photon and either lepton in the J(psi) rest frame. The decay /sup 3/P/sub 0/ ..-->.. J(psi) + ..gamma.. (which must have W(/sup 3/P/sub 0/,theta) approximately 1 + cos/sup 2/theta) is predicted to be suppressed.
Date: January 1, 1975
Creator: Babcock, J. & Rosner, J. L
Partner: UNT Libraries Government Documents Department

Minimally extended elctroweak gauge theories in SO(10) and E/sub 6/

Description: The possibility of minimally extending the standard SU(2)/sub L/xU(1) electroweak theory within the context of SO(10) and E/sub 6/ grand unification by adding U(1) factors is explored. The neutrino neutral-current interactions in these schemes are arranged to coincide with the standard-model predictions. Limits on the masses of the extra Z's generated by these U(1) factors are obtained by considering other parity-violating effects. Additional Z's as light as 2.5 to 3.0 times the standard model Z/sup 0/ mass are allowed.
Date: November 1, 1982
Creator: Robinett, R.W. & Rosner, J.L.
Partner: UNT Libraries Government Documents Department

Current quarks, constituent quarks, and symmetries of resonance decays

Description: The transformation between ''current'' quarks and ''constituent'' quarks recently suggested by Melosh is examined with respect to its predictions for pionic decays of resonances. It implies the use of SU(6)/sub W/ for classifying particle states but not for describing decay processes. lnstead, pion emission proceeds via DELTA L/sub z/ = 0, plus or minus 1, where L is the internal (''quark'') orbital angular momentum. This decay symmetry is called SU(6)/sub W/ (DELTA L/sub z/ = 0, plus or minus 1). It is proven equivalent for any decay A yields B + pi (where A, B are arbitrary qq-bar or qqq hadrons) to the /sup 3/P/sub 0/ quark-pair creation model for such decays, as formulated by Micu, Colglazier, Petersen and Rosner. The roles of final orbital angular momenta l and of SU(3) x SU(3) subgroups of SU(6)w are also discussed, and some new predictions are made for decays of meson resonances below 1700 MeV. (auth)
Date: April 18, 1973
Creator: Hey, A.J.G.; Rosner, J.L. & Weyers, J.
Partner: UNT Libraries Government Documents Department