Screened alpha decay in dense astrophysical plasmas and magnetars

This paper shows that ultrastrong magnetic fields (such as those of magnetars) and dense astrophysical plasmas can reduce the half life of alpha decaying nuclei by many orders of magnitude. In such environments the conventional Geiger-Nuttall law is modifed so that all half lives are shifted to dramatically lower values. Those effects, which have never been investigated before, may have significant implications on the universal abundances of heavy radioactive elements and the cosmochronological methods that rely on them.Comment: 15 RevTex pages, 3 ps figures (minor revision). This work was presented during the conference ''Supernova, 10 years of SN1993J'', April 2003, Valencia, Spain. Accepted for publication in Phys.Rev.

Heuristic Segmentation of a Nonstationary Time Series

Many phenomena, both natural and human-influenced, give rise to signals whose statistical properties change under time translation, i.e., are nonstationary. For some practical purposes, a nonstationary time series can be seen as a concatenation of stationary segments. Using a segmentation algorithm, it has been reported that for heart beat data and Internet traffic fluctuations--the distribution of durations of these stationary segments decays with a power law tail. A potential technical difficulty that has not been thoroughly investigated is that a nonstationary time series with a (scale-free) power law distribution of stationary segments is harder to segment than other nonstationary time series because of the wider range of possible segment sizes. Here, we investigate the validity of a heuristic segmentation algorithm recently proposed by Bernaola-Galvan et al. by systematically analyzing surrogate time series with different statistical properties. We find that if a given nonstationary time series has stationary periods whose size is distributed as a power law, the algorithm can split the time series into a set of stationary segments with the correct statistical properties. We also find that the estimated power law exponent of the distribution of stationary-segment sizes is affected by (i) the minimum segment size, and (ii) the ratio of the standard deviation of the mean values of the segments, and the standard deviation of the fluctuations within a segment. Furthermore, we determine that the performance of the algorithm is generally not affected by uncorrelated noise spikes or by weak long-range temporal correlations of the fluctuations within segments.Comment: 23 pages, 14 figure

Radiatively Induced Neutrino Masses and Large Higgs-Neutrino Couplings in the Standard Model with Majorana Fields

The Higgs sector of the Standard Model with one right-handed neutrino per family is systematically analyzed. In a model with intergenerational independent mixings between families, we can account for very light neutrinos acquiring Majorana masses radiatively at the first electroweak loop level. We also find that in such a scenario the Higgs coupling to the light-heavy neutrinos and to the heavy-heavy ones may be remarkably enhanced with significant implications for the production of these heavy neutrinos at high energy colliders.Comment: Making the text of an old paper electronically availabl

Constraints on Baryon-Nonconserving Yukawa Couplings in a Supersymmetric Theory

The 1-loop evolution of couplings in the minimal supersymmetric standard model, extended to include baryon nonconserving $(B\!\!\!/)$ operators through explicit $R$-parity violation, is considered keeping only $B\!\!\!/$ superpotential terms involving the maximum possible number of third generation superfields. If all retained Yukawa couplings $Y_i$ are required to remain in the perturbative domain $(Y_i < 1)$ upto the scale of gauge group unification, upper bounds ensue on the magnitudes of the $B\!\!\!/$ coupling strengths at the supersymmetry breaking scale, independent of the model of unification. They turn out to be similar to the corresponding fixed point values reached from a wide range of $Y_i$ (including all $Y_i$ greater than unity) at the unification scale. The coupled evolution of the top and $B\!\!\!/$ Yukawa couplings results in a reduction of the fixed point value of the former.Comment: PRL-TH-94/8 and TIFR/TH/94-7, 15 pages, LaTe

Littlest Higgs model and associated ZH production at high energy e+e−e^{+}e^{-} collider

In the context of the littlest Higgs (LH) model, we consider the Higgs strahlung process $e^{+}e^{-}\to ZH$. We find that the correction effects on this process mainly come from the heavy photon $B'$. If we take the mixing angle parameter $c$ in the range of 0.75 - 1, the contributions of the heavy gauge boson $W_{3}'$ is larger than 6%. In most of the parameter space, the deviation of the total production cross section $\sigma^{tot}$ from its SM value is larger than 5%, which may be detected in the future high energy $e^{+}e^{-}$ collider (LC) experiments. The future LC experiments could test the LH model by measuring the cross section of the process $e^{+}e^{-}\to ZH$.Comment: 13 pages, 3 figure

Beautiful Mirrors and Precision Electroweak Data

The Standard Model (SM) with a light Higgs boson provides a very good description of the precision electroweak observable data coming from the LEP, SLD and Tevatron experiments. Most of the observables, with the notable exception of the forward-backward asymmetry of the bottom quark, point towards a Higgs mass far below its current experimental bound. The disagreement, within the SM, between the values for the weak mixing angle as obtained from the measurement of the leptonic and hadronic asymmetries at lepton colliders, may be taken to indicate new physics contributions to the precision electroweak observables. In this article we investigate the possibility that the inclusion of additional bottom-like quarks could help resolve this discrepancy. Two inequivalent assignments for these new quarks are analysed. The resultant fits to the electroweak data show a significant improvement when compared to that obtained in the SM. While in one of the examples analyzed, the exotic quarks are predicted to be light, with masses below 300 GeV, and the Higgs tends to be heavy, in the second one the Higgs is predicted to be light, with a mass below 250 GeV, while the quarks tend to be heavy, with masses of about 800 GeV. The collider signatures associated with the new exotic quarks, as well as the question of unification of couplings within these models and a possible cosmological implication of the new physical degrees of freedom at the weak scale are also discussed.Comment: 21 pages, 4 embedded postscript figures, LaTeX. Two minor corrections performe

Quantifying measuring errors of new residential water meters considering different customer consumption patterns

Water meter measuring errors vary depending on the water flow rate. The difference between water actually consumed and registered by a meter will differ depending on how water consumption is distributed by flow rates. Published studies assessing the performance of new residential meters have only analysed the error curves of the meters without calculating the influence that consumption patterns have on their field performance. In most cases, research has been limited to analysing compliance with published standards. This work presents an evaluation of the actual commercial losses to be expected considering the consumption characteristic of domestic users. Several types of residential meters have been tested and the error curves obtained have been combined with measured consumption patterns of domestic users. As a result, this paper provides information about the order of magnitude of the initial measuring error as a function of the residential meter model and user characteristics.The translation of this paper was funded by the Universitat Politecnica de Valencia, Spain.Arregui De La Cruz, F.; Balaguer Garrigós, M.; Soriano Olivares, J.; García-Serra García, J. (2015). Quantifying measuring errors of new residential water meters considering different customer consumption patterns. Urban Water Journal. 13(5):463-475. doi:10.1080/1573062X.2014.993999S463475135American Water Works Association (AWWA), 1999. Water Meters - Selection, Installation, Testing, and Maintenance: Manual of Water Supply Practices (M6). Denver, CO: American Water Works Association.American Water Works Association (AWWA), 2009. Water Audits and Loss Control Programs: AWWA Manual M36. Denver, CO: American Water Works Association.Arregui, F.J., CabreraJr, E., and Cobacho, R., 2006a. Integrated water meter management. London: IWA Publishing.Arregui, F. ., Cabrera, E., Cobacho, R., & García-Serra, J. (2006). Reducing Apparent Losses Caused By Meters Inaccuracies. Water Practice and Technology, 1(4). doi:10.2166/wpt.2006.093Arregui, F.J., Martinez, B., Soriano, J., and Parra, J.C., 2009. Tools for improving decision making in water meter management. Proceedings of the 5th IWA Water Loss Reduction Specialist Conference (pp. 225–232). Cape Town, South Africa.Barfuss, S.L., Johnson, M.C., and Neilsen, M.A., 2011. Accuracy of in-service water meters at low and high flow rates. Denver, CO: Water Research Foundation, Denver.Blokker, E. J. M., Vreeburg, J. H. G., & van Dijk, J. C. (2010). Simulating Residential Water Demand with a Stochastic End-Use Model. Journal of Water Resources Planning and Management, 136(1), 19-26. doi:10.1061/(asce)wr.1943-5452.0000002Bowen, P.T., Harp, J.F., Hendricks, J.E., and Shoeleh, M., 1991. Evaluating residential meter performance. Denver, CO: American Water Works Association Research Foundation.Bowen, P.T., Harp, J.F., Baxter, J.W., and Shull, R.D., 1993. Residential water use patterns. Denver, CO: American Water Works Association Research Foundation.Criminisi, A., Fontanazza, C. M., Freni, G., & Loggia, G. L. (2009). Evaluation of the apparent losses caused by water meter under-registration in intermittent water supply. Water Science and Technology, 60(9), 2373-2382. doi:10.2166/wst.2009.423DeOreo, W.B. and Mayer, P.W., 2013. Residential end uses of water study update. Denver, CO: Water Research Foundation.ISO 4064-3, 1993. Measurement of water flow in closed conduits - meters for cold potable water. Part 3: Test methods and equipment. Geneva: International Organization for Standardization.ISO 4064-1, 2005. Measurement of water flow in a fully charged closed conduit - meters for cold potable water and hot water. Part 1: Specifications. Geneva: International Organization for Standardization.Lievers, C. and Barendregt, A., 2009. Implementation of intervention techniques to decrease commercial losses for Ghana. Proceedings of the 5th IWA Water Loss Reduction Specialist Conference (pp. 490–496). Cape Town, South Africa.Male, J.W., Noss, R.R., and Moore, I.C., 1985. Identifying and Reducing Losses in Water Distribution Systems. Saddle River, NJ: Noyes Publications.Mayer, P.W., DeOreo, W.B., Opitz, E.M., Kiefer, J.C., Davis, W.Y., Dziegielewski, B., and Nelson, J.O., 1999. Residential End Uses of Water. Denver, CO: AWWA Research Foundation and American Water Works Association.Mutikanga, H. E., Sharma, S. K., & Vairavamoorthy, K. (2010). Assessment of apparent losses in urban water systems. Water and Environment Journal, 25(3), 327-335. doi:10.1111/j.1747-6593.2010.00225.xNeilsen, M. A., Barfuss, S. L., & Johnson, M. C. (2011). Off-the-shelf accuracies of residential water meters. Journal - American Water Works Association, 103(9), 48-55. doi:10.1002/j.1551-8833.2011.tb11531.xRichards, G. L., Johnson, M. C., & Barfuss, S. L. (2010). Apparent losses caused by water meter inaccuracies at ultralow flows. Journal - American Water Works Association, 102(5), 123-132. doi:10.1002/j.1551-8833.2010.tb10115.xRizzo, A. and Cilia, J., 2005. Quantifying meter under-registration caused by the ball valves of roof tanks (for indirect plumbing systems). Proceedings of the Leakage 2005 Conference, Halifax, Canada.Thornton, J., Sturm, R., and Kunkel, G., 2008. Water Loss Control. New York: McGraw-Hill.Woltmann, 2008. ITA. Valencia, Spain: Universitat PolitecnicaRetrieved from: http://www.ita.upv.es/software/presentacion-en.php.Yaniv, S., 2012. Reduction of apparent losses using the UFR (Unmeasured-flow reducer): Case studies. Proceedings of the 5th IWA Specialist Conference on Efficient Water Use and Management. Hague, The Netherlands.Yee, M. D. (1999). Economic analysis for replacing residential meters. Journal - American Water Works Association, 91(7), 72-77. doi:10.1002/j.1551-8833.1999.tb08666.

Phenomenological constraints on SUSY SU(5) GUTs with non-universal gaugino masses

We study phenomenological aspects of supersymmetric SU(5) grand unified theories with non-universal gaugino masses. For large tan beta, we investigate constraints from the requirement of successful electroweak symmetry breaking, the positivity of stau mass squared and the b to s gamma decay rate. In the allowed region, the nature of the lightest supersymmetric particle is determined. Examples of mass spectra are given. We also calculate loop corrections to the bottom mass due to superpartners.Comment: 10 pages, 2 figures (8 eps files), uses REVTeX. Replaced to match the version to be published in PRD: minor corrections and addition

Force and Motion Generation of Molecular Motors: A Generic Description

We review the properties of biological motor proteins which move along linear filaments that are polar and periodic. The physics of the operation of such motors can be described by simple stochastic models which are coupled to a chemical reaction. We analyze the essential features of force and motion generation and discuss the general properties of single motors in the framework of two-state models. Systems which contain large numbers of motors such as muscles and flagella motivate the study of many interacting motors within the framework of simple models. In this case, collective effects can lead to new types of behaviors such as dynamic instabilities of the steady states and oscillatory motion.Comment: 29 pages, 9 figure