Flavor constraints on electroweak ALP couplings

We explore the signals of axion-like particles (ALPs) in flavor-changing neutral current (FCNC) processes. The most general effective linear Lagrangian for ALP couplings to the electroweak bosonic sector is considered, and its contribution to FCNC decays is computed up to one-loop order. The interplay between the different couplings opens new territory for experimental exploration, as analyzed here in the ALP mass range $0<m_a \lesssim 5$ GeV. When kinematically allowed, $K\to \pi \nu \bar{\nu}$ decays provide the most stringent constraints for channels with invisible final states, while $B$-meson decays are more constraining for visible decay channels, such as displaced vertices in $B\to K^{(\ast)} \mu^+ \mu^-$ data. The complementarity with collider constraints is discussed as well.Comment: 12 pages, 6 figure

The Axion and the Goldstone Higgs

We consider the renormalizable $SO(5)/SO(4)$ $\sigma$-model, in which the Higgs particle has a pseudo-Nambu-Goldstone boson character, and explore what the minimal field extension required to implement the Peccei-Quinn symmetry (PQ) is, within the partial compositeness scenario. It turns out that the minimal model does not require the enlargement of the exotic fermionic sector, but only the addition of a singlet scalar: it is sufficient that the exotic fermions involved in partial compositeness and the singlet scalar become charged under Peccei-Quinn transformations. We explore the phenomenological predictions for photonic signals in axion searches for all models discussed. Because of the constraints imposed on the exotic fermion sector by the Standard Model fermion masses, the expected range of allowed axion-photon couplings turns out to be generically narrowed with respect to that of standard invisible axion models, impacting the experimental quest.Comment: 31 pages, 2 Figures. Description improved, results unchange

Transportation infrastructure network design in the presence of modal competition: computational complexity classification and a genetic algorithm

[EN] In this paper we analyze the computational complexity of transportation infrastructure network design problems, in the presence of a competing transportation mode. Some of these problems have previously been introduced in the literature. All problems studied have a common objective: the maximization of the number of travelers using the new network to be built. The differences between them are due to two factors. The first one is the constraints that the new network should satisfy: (1) budget constraint, (2) no-cycle constraint, (3) both constraints. The second factor is the topology of the network formed by the feasible links and stations: (1) a general network, (2) a forest. By combining these two factors, in total we analyze six problems, five of them are shown to be NP-hard, the sixth being trivial. Due to the NP-hardness of these problems, a genetic algorithm is proposed. Computational experiments show the applicability of this algorithm.Mozart Menezes and Juan A. Mesa were partially supported by project MTM2015- 67706-P (MINECO/FEDER,UE). Federico Perea was partially supported by the Spanish Ministry of Science, Innovation, and Universities, under projects "OPTEP-Port Terminal Operations Optimization" (No. RTI2018-094940-B-I00) and MTM2016-74983, fnanced with FEDER funds, and by the Universitat Politècnica de València under grant SP20180164 of the program Primeros Proyectos de Investigaciòn (PAID-06-18), Vicerrectorado de Investigaciòn, Innovaciòn y Transferencia. All this support is gratefully acknowledged.Perea Rojas Marcos, F.; Menezes, MBC.; Mesa, JA.; Rubio-Del-Rey, F. (2020). Transportation infrastructure network design in the presence of modal competition: computational complexity classification and a genetic algorithm. Top. 28(2):442-474. https://doi.org/10.1007/s11750-019-00537-xS442474282Balakrishnan A, Magnanti TL, Mirchandani P (1997) Network design. Annotated bibliography in combinatorial optimization. Wiley, New YorkBussieck M, Winter T, Zimmermann U (1997) Discrete optimization in public rail transport. Math Prog 79(1–3):415–444Chakroborty P (2003) Genetic algorithms for optimal urban transit network design. Comput Aided Civ Infrastruct Eng 18:184–200Chakroborty P, Dwivedi T (2002) Optimal route network design for transit systems using genetic algorithms. Eng Optim 34(1):83–100Desaulniers G, Hickman MD (2007) Public transit. Transportation Handbooks in operations research and management science, vol 14. Elsevier, Amsterdam, pp 69–127García-Archilla B, Lozano AJ, Mesa JA, Perea F (2013) GRASP algorithms for the robust railway network design problem. J Heuristics 19(2):399–422Garey M, Johnson DS (1979) Computers and Intractability: a guide to the theory of NP-completeness. W.H Freeman and Company, USGoel G, Karande C, Tripathi P, Wanga L (2010) Approximability of combinatorial problems with multi-agent submodular cost functions. ACM SIGecom Exch 9(1):1–4Grötschel M, Lovász L, Schrijver A (1981) The ellipsoid method and its consequences in combinatorial optimization. Combinatorica 1:169–197Grötschel M, Lovász L, Schrijver A (1993) Geometric algorithms and combinatorial optimization, 2nd edn. Springer-Verlag, New YorkGuihaire V, Hao JK (2008) Transit network design and scheduling: a global review. Transp Res Part A 42:1251–1273Jegelka SS (2012) Combinatorial problems with sub-modular coupling in machine learning and computer vision. Thesis ETH ZurichLaporte G, Mesa JA, Ortega FA (1995) Assessing the efficiency of rapid transit configurations. Top 5:95–104Laporte G, Mesa JA, Perea F (2010) A game theoretic framework for the robust railway transit network design problem. Transp Res Part B 44:447–459Magnanti TL, Wong RT (1984) Network design and transportation planning: models and algorithms. Transp Sci 18:1–55Marín A, García-Ródenas R (2009) Location of infrastructure in urban railway networks. Comput Oper Res 36(5):1461–1477Mesa JA, Boffey BT (1996) A review of extensive facility location in networks. Eur J Oper Res 95:592–603Nayeem MA, Rahman MK, Rahman MS (2014) Transit network design by genetic algorithm with elitism. Transp Res Part C 46:30–45Nemhauser GL, Wolsey LA (1999) Integer and combinatorial optimization. Wiley, AmsterdamPerea F, Mesa JA, Laporte G (2014) Adding a new station and a road link to a road-rail network in the presence of modal competition. Transp Res Part B 68:1–16Puerto J, Ricca F, Scozzari A (2018) Extensive facility location problems on networks: an updated review. TOP 26(2):187–226Schmidt M, Schöbel A (2014) Location of speed-up subnetworks. Ann Oper Res 223(1):379–401Schöbel A (2012) Line planning in public transportation: models and methods. OR Spectr 34(3):491–510Sourirajan K, Ozsen L, Uzsoy R (2009) A genetic algorithm for a single product network design model with lead time and safety stock considerations. Eur J Oper Res 197(2):599–608Székely L, Wang H (2005) On subtrees of trees. Adv Appl Math 34:138–155Ukkusuri SV, Mathew TV, Waller ST (2007) Robust transportation network design under demand uncertainty. Comput Aided Civ Infrast Eng 22:6–1

Goitre and Iodine Deficiency in Europe

The prevalence of endemic iodine-deficiency goitre in Europe has been reduced in many areas by the introduction of iodination programmes. Recent reports, however, show that goitre remains a significant problem and that its prevalence has not decreased in a number of European countries. Hetzel1 has pointed out that the high global prevalence of iodine-deficiency disorders could be eradicated within 5-10 years by introduction of an iodised salt programme. The current World Health Organisation recommendations for iodine intake are between 150 and 300 μg/da

Modelos numéricos para estudios de incendio en túneles con ventilación longitudinal

En casos de accidentes severos en túneles se requiere una adecuada estrategia para evitar pérdidas humanas. En túneles con ventilación longitudinal el recurso fundamental es la actuación sobre los ventiladores de chorro para dirigir o concentrar la nube de humo. Las situaciones más comprometidas se presentan en túneles con doble sentido de circulación. En este artículo se presentan varios modelos numéricos de distinta complejidad y coste que permiten el análisis e interpretación de accidentes con fuego. Finamente se muestran ejemplos de aplicación a casos reales, en particular los realizados para los túneles de El Negrón II y Los Yébenes

Non-linear Higgs portal to Dark Matter

The Higgs portal to scalar Dark Matter is considered in the context of non-linearly realised electroweak symmetry breaking. We determine the dominant interactions of gauge bosons and the physical Higgs particle h to a scalar singlet Dark Matter candidate. Phenomenological consequences are also studied in detail, including the possibility of distinguishing this scenario from the standard Higgs portal in which the electroweak symmetry breaking is linearly realised. Two features of significant impact are: i) the connection between the electroweak scale v and the Higgs particle departs from the (v + h) functional dependence, as the Higgs field is not necessarily an exact electroweak doublet; ii) the presence of specific couplings that arise at different order in the non-linear and in the linear expansions. These facts deeply affect the Dark Matter relic abundance, as well as the expected signals in direct and indirect searches and collider phenomenology, where Dark Matter production rates are enhanced with respect to the standard portal

Bubble concentration on spheres for supercritical elliptic problems

We consider the supercritical Lane-Emden problem (P_\eps)\qquad -\Delta v= |v|^{p_\eps-1} v \ \hbox{in}\ \mathcal{A} ,\quad u=0\ \hbox{on}\ \partial\mathcal{A} where $\mathcal A$ is an annulus in \rr^{2m}, $m\ge2$ and p_\eps={(m+1)+2\over(m+1)-2}-\eps, \eps>0. We prove the existence of positive and sign changing solutions of (P_\eps) concentrating and blowing-up, as \eps\to0, on $(m-1)-$dimensional spheres. Using a reduction method (see Ruf-Srikanth (2010) J. Eur. Math. Soc. and Pacella-Srikanth (2012) arXiv:1210.0782)we transform problem (P_\eps) into a nonhomogeneous problem in an annulus \mathcal D\subset \rr^{m+1} which can be solved by a Ljapunov-Schmidt finite dimensional reduction