47 research outputs found

    The Custodial Randall-Sundrum Model: From Precision Tests to Higgs Physics

    Full text link
    We reexamine the Randall-Sundrum (RS) model with enlarged gauge symmetry SU(2)_L x SU(2)_R x U(1)_X x P_LR in the presence of a brane-localized Higgs sector. In contrast to the existing literature, we perform the Kaluza-Klein (KK) decomposition within the mass basis, which avoids the truncation of the KK towers. Expanding the low-energy spectrum as well as the gauge couplings in powers of the Higgs vacuum expectation value, we obtain analytic formulas which allow for a deep understanding of the model-specific protection mechanisms of the T parameter and the left-handed Z-boson couplings. In particular, in the latter case we explain which contributions escape protection and identify them with the irreducible sources of P_LR symmetry breaking. We furthermore show explicitly that no protection mechanism is present in the charged-current sector confirming existing model-independent findings. The main focus of the phenomenological part of our work is a detailed discussion of Higgs-boson couplings and their impact on physics at the CERN Large Hadron Collider. For the first time, a complete one-loop calculation of all relevant Higgs-boson production and decay channels is presented, incorporating the effects stemming from the extended electroweak gauge-boson and fermion sectors.Comment: 74 pages, 13 figures, 3 tables. v2: Matches version published in JHE

    Reliability and tolerance comparison in water supply networks

    Full text link
    The final publication is available at Springer via http://dx.doi.org/10.1007/s11269-010-9753-2Urban water supply is a high priority service and so looped networks are extensively used in order to considerably reduce the number of consumers affected by a failure. Looped networks may be redundant in connectivity and capacity. The concept of reliability has been introduced in an attempt to quantitatively measure the possibility of maintaining an adequate service for a given period. Numerous researchers have considered reliability as a measure of redundancy. This concept is usually implicit, but some researchers have even stated it explicitly. This paper shows why reliability cannot be considered a measure of redundancy given that branched networks can achieve high values of reliability and this would deny the fact that a looped network is more reliable than a branched network with a similar layout and size. To this end the paper discusses two quantitative indices for measuring expected network behavior: reliability and tolerance. These indices are calculated and a comparison is made between looped, branched, and mixed networks. © 2011 Springer Science+Business Media B.V.The authors wish to acknowledge the support received from project IDAWAS, DPI2009-11591, of the Directorate-General of Research at the Spanish Ministry of Education, the grant PAID-02-09 for a stay at the Universidad Politecnica de Valencia by the first author, and a grant MAEC-AECI 0000202066 awarded to the second author by the Ministerio de Asuntos Exteriores y Cooperacion of Spain. The use of English in this paper was revised by John Rawlins; and the revision was funded by the Universidad Politecnica de Valencia, Spain.Martínez-Rodríguez, JB.; Montalvo Arango, I.; Izquierdo Sebastián, J.; Pérez García, R. (2011). Reliability and tolerance comparison in water supply networks. Water Resources Management. 25(5):1437-1448. https://doi.org/10.1007/s11269-010-9753-2S14371448255Bao Y, Mays LW (1990) Model for water distribution system reliability. J Hydraul Eng ASCE 116(9):1119–1137Bouchart F, Goulter I (1991) Reliability improvements in design of water distribution networks recognizing valve location. Water Resour Res 27(12):3029–3040Carrión A, Solano H, Gamiz ML, Debón A (2010) Evaluation of the reliability of a water supply network from right-censored and left-truncated break data. Water Resour Manag, Springer Sci 24:2917–2935. Published online: 28 January 2010Chiong C (1985) Optimización de redes cerradas, Doctoral Thesis, CIH-CUJAE, Havana (in Spanish)Christodoulou SE (2010) Water network assessment and reliability analysis by use of survival analysis. Water Resour Manag, Springer Sci, Published online: 19 June 2010Cullinane MJ, Lansey KE, Mays LW (1992) Optimization-availability-based design of water distribution networks. J Hydraul Eng ASCE 118(3):420–441Duan N, Mays LW, Lansey KE (1990) Optimal reliability-based design of pumping and distribution systems. J Hydraul Eng ASCE 116(2):249–268Goulter I (1992) Systems analysis in water distribution network design: from theory to practice. J Water Resour Plan Manage ASCE 118(3):238–248Goulter I (1993) Modern concepts of a water distribution system. Policies for improvement of networks with shortcomings. In: Cabrera E, Martínez F (eds) Water supply systems: state of the art and future trends, Valencia (Spain). Comput Mech Publ, Southampton, pp 121–138Goulter I, Bouchart F (1990) Reliability-constrained pipe network model. J Hydraul Eng ASCE 116(2):211–229Gupta R, Bhave R (1994) Reliability analysis of water distribution systems. J Environ Eng ASCE 120(2):447–460Jacobs P, Goulter I (1991) Estimation of maximum cut-set size for water network failure. J Water Resour Plan Manage ASCE 117(5):588–605Jowitt P, Xu C (1993) Predicting pipe failure effects in water distribution networks. J Water Resour Plan Manage ASCE 119(l):18–31Kalungi P, Tanyimboh TT (2003) Redundancy model for water distribution systems. Rel Eng Syst Safety 82(3):275–286Khomsi D, Walters GA, Thorley ARD, Ouazar D (1996) Reliability tester for water-distribution networks. J Comput Civ Eng ASCE 10(l):10–9Lansey K, Duan N, Mays LW, Tung YK (1989) Water distribution system design under uncertainty. J Water Resour Plan Manage ASCE 115(5):630–645Loganathan GV, Shah MP, Sherali HP (1990) A two-phase network design heuristic for minimum cost water distribution systems under a reliability constraint. Eng Optim 15(4):311–336Martínez JB (2007) Quantifying the economy of water supply looped networks. J Hydraul Eng ASCE 133(1):88–97Martínez JB (2010) Cost and reliability comparison between branched and looped water supply networks. J Hydroinform IWA 12(2):150–160Morgan DR, Goulter IC (1985) Optimal urban water distribution design. Water Resour Res 21(5):642–652Park H, Leibman J (1993) Redundancy-constrained minimum-cost design of water distribution networks. J Water Resour Plan Manage ASCE 119(l):83–98Pinto J, Varum H, Bentes I, Agarwal J (2010) A theory of vulnerability of water pipe network. Water Resour Manag 24:4237–4254. Springer Science, Published online: 6 May 2010Quimpo R, Shamsi U (1991) Reliability-based distribution system maintenance. J Water Resour Plan Manage ASCE 117(3):321–339Su Y, Mays LW, Duan N, Lansey K (1987) Reliability based optimization model for water distribution systems. J Hydraul Eng ASCE 113(12):1539–1556Tanyimboh TT, Tabesh M, Burrows R (2001) Appraisal of source head methods for calculating reliability of water distribution networks. J Water Resour Plan Manage ASCE 127(4):206–213Walski TM, Weiler JS, Culver T (2006) Using criticality analysis to identify impact of valve location. In: Proc 8th annual water distrib systems analysis symposium, August 27–30, Cincinnati, Ohio, USA,Walters GA, Knezevic J (1989) Discussion of ‘Reliability based optimization model for water distribution systems’ by Su, Y., Mays, L. W. , Duan, N., and Lansey, K. J Hydraul Eng ASCE 115(8):1157–1158Xu C, Goulter I (1997) Simulation-based optimal design of reliable water distribution networks. In: Zayegh A (ed) Proc 3rd int conf on modeling and simulation. Victoria University of Technology, Melbourne, pp 107–112Xu C, Goulter I (1998) Probabilistic model for water distribution reliability. J Water Resour Plan Manage ASCE 124(4):218–228Xu C, Goulter I (1999) Reliability based optimal design of water distribution networks. J Water Resour Plan Manage ASCE 125(6):352–362Xu C, Goulter I (2000) A model for optimal design of reliable water distribution networks. In: Blain WR, Brebbia CA (eds) Hydraulic engineering software VIII. WIT, Southampton, pp 71–8

    LHC signatures of warped-space vectorlike quarks

    Full text link
    We study the LHC signatures of TeV scale vectorlike quarks b′b', t′t' and χ\chi with electromagnetic charges -1/3, 2/3 and 5/3 that appear in many beyond the standard model (BSM) extensions. We consider warped extra-dimensional models and analyze the phenomenology of such vectorlike quarks that are the custodial partners of third generation quarks. In addition to the usually studied pair-production channels which depend on the strong coupling, we put equal emphasis on single production channels that depend on electroweak couplings and on electroweak symmetry breaking induced mixing effects between the heavy vectorlike quarks and standard model quarks. We identify new promising gggg-initiated pair and single production channels and find the luminosity required for discovering these states at the LHC. For these channels, we propose a cut that allows one to extract the relevant electroweak couplings. Although the motivation is from warped models, we present many of our results model-independently.Comment: Published version. 40 pages, 19 figures, 12 tables. References added. Minor revision

    Decision mapping:Understanding decision making processes

    No full text
    The task of arriving at an engineering decision typically involves extensive and complex analyses, the evaluation of alternatives, and the resolution of conflicts between stakeholders. Research into institutional frameworks, decision making, and decision support tools have guided improvements in the quality of decisions. However, existing organisational structures and decision frameworks must be acknowledged and addressed if the desired improvements are to be realised. A mapping technique is proposed that allows the existing decision-making processes and information flows to be identified and analysed. The result is a mechanism to understand the context and processes of the decision task, and ultimately to aid in the introduction of new decision protocols and decision support systems
    corecore