Renormalization group parameter evolution of the minimal supersymmetric standard model with R-parity violation

A comparison of spectra obtained using the 1-loop MSSM and 2-loop R-parity violating MSSM renormalization group equations is presented. Influence of higher loop corrections and R-parity violating terms is discussed. Some numerical constraints on the R-parity violating parameters are also given.Comment: 4 pages, 1 figure, using RevTE

Grand unified theory constrained supersymmetry and neutrinoless double beta decay

We analyze the contributions to the neutrinoless double $\beta$ decay ($0\nu\beta\beta$-decay) coming from the Grand Unified Theory (GUT) constrained Minimal Supersymmetric Standard Model (MSSM) with trilinear R-parity breaking. We discuss the importance of two-nucleon and pion-exchange realizations of the quark-level $0\nu\beta\beta$-decay transitions. In this context, the questions of reliability of the calculated relevant nuclear matrix elements within the Renormalized Quasiparticle Random Phase Approximation (pn-RQRPA) for several medium and heavy open-shell nuclei are addressed. The importance of gluino and neutralino contributions to $0\nu\beta\beta$-decay is also analyzed. We review the present experiments and deduce limits on the trilinear R-parity breaking parameter $\lambda_{111}'$ from the non-observability of $0\nu\beta\beta$-decay for different GUT constrained SUSY scenarios. In addition, a detailed study of limits on the MSSM parameter space coming from the $B \to X_s \gamma$ processes by using the recent CLEO and OPAL results is performed. Some studies in respect to the future $0\nu\beta\beta$-decay project GENIUS are also presented.Comment: 29 pages, 8 figure

Additional Nucleon Current Contributions to Neutrinoless Double Beta Decay

We have examined the importance of momentum dependent induced nucleon currents such as weak-magnetism and pseudoscalar couplings to the amplitude of neutrinoless double beta decay in the mechanisms of light and heavy Majorana neutrino as well as in that of Majoron emission. Such effects are expected to occur in all nuclear models in the direction of reducing the light neutrino matrix elements by about 30%. To test this we have performed a calculation of the nuclear matrix elements of the experimentally interesting nuclei A = 76, 82, 96, 100, 116, 128, 130, 136 and 150 within the pn-RQRPA. We have found that indeed such corrections vary somewhat from nucleus to nucleus, but in all cases they are greater than 25 percent. In the case of heavy neutrino the effect is much larger (a factor of 3). Combining out results with the best presently available experimental limits on the half-life of the neutrinoless double beta decay we have extracted new limits on the effective neutrino mass (light and heavy) and the effective Majoron coupling constant.Comment: 31 pages, RevTex, 3 Postscript figures, submitted to Phys. Rev.

Neutrinoless Double Beta Decay in Gauge Theories

Neutrinoless double beta decay is a very important process both from the particle and nuclear physics point of view. Its observation will severely constrain the existing models and signal that the neutrinos are massive Majorana particles. From the elementary particle point of view it pops up in almost every model. In addition to the traditional mechanisms, like the neutrino mass, the admixture of right handed currents etc, it may occur due to the R-parity violating supersymmetric (SUSY) interactions. From the nuclear physics point of view it is challenging, because: 1) The relevant nuclei have complicated nuclear structure. 2) The energetically allowed transitions are exhaust a small part of all the strength. 3) One must cope with the short distance behavior of the transition operators, especially when the intermediate particles are heavy (eg in SUSY models). Thus novel effects, like the double beta decay of pions in flight between nucleons, have to be considered. 4) The intermediate momenta involved are about 100 MeV. Thus one has to take into account possible momentum dependent terms in the nucleon current. We find that, for the mass mechanism, such modifications of the nucleon current for light neutrinos reduce the nuclear matrix elements by about 25 per cent, almost regardless of the nuclear model. In the case of heavy neutrinos the effect is much larger and model dependent. Taking the above effects into account, the available nuclear matrix elements for the experimentally interesting nuclei A = 76, 82, 96, 100, 116, 128, 130, 136 and 150 and the experimental limits on the life times we have extracted new stringent limits on the average neutrino mass and on the R-parity violating coupling for various SUSY models.Comment: Latex, 24 pages, 1 postscript figure, uses iopconf.st

The (muon^-,muon^+) conversion in nuclei as a probe of new physics

A detailed study of the muonic analogue of neutrinoless double beta decay, (muon^-,muon^+) conversion, has been carried out for the A=44 nuclear system. We studied several lepton number violating (LNV) mechanisms potentially triggering this process: exchange by light and heavy Majorana neutrinos as well as exchange by supersymmetric particles participating in R-parity violating interactions. The nuclear structure has been taken into account within the renormalized Quasiparticle Random Phase Approximation method. To our knowledge, this is the first realistic treatment of nuclear structure aspects of the (muon^-,muon^+) conversion. We estimated the rate of this process utilizing the existing experimental constraints on the parameters of the underlying LNV interactions and conclude that the (muon^-,muon^+) conversion is hardly detectable in the near future experiments.Comment: 23 pages, RevTex, 3 Postscript figure

Neutrinoless double-beta decay and effective field theory

We analyze neutrinoless double $\beta$-decay (\nbb-decay) mediated by heavy particles from the standpoint of effective field theory. We show how symmetries of the \nbb-decay quark operators arising in a given particle physics model determine the form of the corresponding effective, hadronic operators. We classify the latter according to their symmetry transformation properties as well as the order at which they appear in a derivative expansion. We apply this framework to several particle physics models, including R-parity violating supersymmetry (RPV SUSY) and the left-right symmetric model (LRSM) with mixing and a right-handed Majorana neutrino. We show that, in general, the pion exchange contributions to \nbb-decay dominate over the short-range four-nucleon operators. This confirms previously published RPV SUSY results and allows us to derive new constraints on the masses in the LRSM. In particular, we show how a non-zero mixing angle $\zeta$ in the left-right symmetry model produces a new potentially dominant contribution to \nbb-decay that substantially modifies previous limits on the masses of the right-handed neutrino and boson stemming from constraints from \nbb-decay and vacuum stability requirements.Comment: 37 pages. Accepted for publication in PR

Stable scheduling of single machine with probabilistic parameters

We consider a stochastic variant of the single machine total weighted tardiness problem jobs parameters are independent random variables with normal or Erlang distributions. Since even deterministic problem is NP-hard, it is difficult to find global optimum for large instances in the reasonable run time. Therefore, we propose tabu search metaheuristics in this work. Computational experiments show that solutions obtained by the stochastic version of metaheuristics are more stable (i.e. resistant to data disturbance) than solutions generated by classic, deterministic version of the algorithm