15,980 research outputs found

    Sum rules for total hadronic widths of light mesons and rectilineal stitch of the masses on the complex plane

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    Mass formulae for light meson multiplets derived by means of exotic commutator technique are written for complex masses and considered as complex mass sum rules (CMSR). The real parts of the (CMSR) give the well known mass formulae for real masses (Gell-Mann--Okubo, Schwinger and Ideal Mixing ones) and the imaginary parts of CMSR give appropriate sum rules for the total hadronic widths - width sum rules (WSR). Most of the observed meson nonets satisfy the Schwinger mass formula (S nonets). The CMSR predict for S nonet that the points (m,Γ)(m,\Gamma{}) form the rectilinear stitch (RS) on the complex mass plane. For low-mass nonets WSR are strongly violated due to ``kinematical'' suppression of the particle decays, but the violation decreases as the mass icreases and disappears above ∼1.5GeV\sim 1.5 GeV. The slope ksk_s of the RS is not predicted, but the data show that it is negative for all S nonets and its numerical values are concentrated in the vicinity of the value -0.5. If ksk_s is known for a nonet, we can evaluate ``kinematical'' suppressions of its individual particles. The masses and the widths of the S nonet mesons submit to some rules of ordering which matter in understanding the properties of the nonet. We give the table of the S nonets indicating masses, widths, mass and width orderings. We show also mass-width diagrams for them. We suggest to recognize a few multiplets as degenerate octets. In Appendix we analyze the nonets of 1+1^+ mesons.Comment: 20 pages, 3 figures; title and discussion expanded; additional text; final version accepted for publication in EPJ

    The multiplets of finite width 0++ mesons and encounters with exotics

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    Complex-mass (finite-width) 0++0^{++} nonet and decuplet are investigated by means of exotic commutator method. The hypothesis of vanishing of the exotic commutators leads to the system of master equations (ME). Solvability conditions of these equations define relations between the complex masses of the nonet and decuplet mesons which, in turn, determine relations between the real masses (mass formulae), as well as between the masses and widths of the mesons. Mass formulae are independent of the particle widths. The masses of the nonet and decuplet particles obey simple ordering rules. The nonet mixing angle and the mixing matrix of the isoscalar states of the decuplet are completely determined by solution of ME; they are real and do not depend on the widths. All known scalar mesons with the mass smaller than 2000MeV2000MeV (excluding σ(600)\sigma(600)) and one with the mass 2200÷2400MeV2200\div2400MeV belong to two multiplets: the nonet (a0(980),K0(1430),f0(980),f0(1710))(a_0(980), K_0(1430), f_0(980), f_0(1710)) and the decuplet (a0(1450),K0(1950),f0(1370),f0(1500),f0(2200)/f0(2330))(a_0(1450), K_0(1950), f_0(1370), f_0(1500), f_0(2200)/f_0(2330)). It is shown that the famed anomalies of the f0(980)f_0(980) and a0(980)a_0(980) widths arise from an extra "kinematical" mechanism, suppressing decay, which is not conditioned by the flavor coupling constant. Therefore, they do not justify rejecting the qqˉq\bar{q} structure of them. A unitary singlet state (glueball) is included into the higher lying multiplet (decuplet) and is divided among the f0(1370)f_0(1370) and f0(1500)f_0(1500) mesons. The glueball contents of these particles are totally determined by the masses of decuplet particles. Mass ordering rules indicate that the meson σ(600)\sigma(600) does not mix with the nonet particles.Comment: 22 pp, 1 fig, a few changes in argumentation, conclusions unchanged. Final version to appear in EPJ

    Sample path large deviations for multiclass feedforward queueing networks in critical loading

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    We consider multiclass feedforward queueing networks with first in first out and priority service disciplines at the nodes, and class dependent deterministic routing between nodes. The random behavior of the network is constructed from cumulative arrival and service time processes which are assumed to satisfy an appropriate sample path large deviation principle. We establish logarithmic asymptotics of large deviations for waiting time, idle time, queue length, departure and sojourn-time processes in critical loading. This transfers similar results from Puhalskii about single class queueing networks with feedback to multiclass feedforward queueing networks, and complements diffusion approximation results from Peterson. An example with renewal inter arrival and service time processes yields the rate function of a reflected Brownian motion. The model directly captures stationary situations.Comment: Published at http://dx.doi.org/10.1214/105051606000000439 in the Annals of Applied Probability (http://www.imstat.org/aap/) by the Institute of Mathematical Statistics (http://www.imstat.org

    Sum rules for total hadronic widths of mesons

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    Mass sum rules for meson multiplets derived from exotic commutators may be written for complex masses. Then the real parts give the well known mass formulae (GM-O, Schwinger, Ideal) and the imaginary ones give the corresponding sum rules for total hadronic widths. The masses and widths of the meson nonets submit to a definite orders. It thus follows that tables of the meson nonets should include information about masses, widths and the orders as well as the mixing angle. The width sum rule for the nonet complying with Schwinger mass formula may be depicted as a straight line in the (m,Γ)(m,\Gamma) plane. It is easily verifiable and satisfied better for high mass nonets.Comment: LaTeX, 4pp, 1 figure. To appear in Proceedings of "Hadron 2001
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