Written evidence [LOL0017]

UK Government Covid-19 Committe

Colliders and Cosmology

Dark matter in variations of constrained minimal supersymmetric standard models will be discussed. Particular attention will be given to the comparison between accelerator and direct detection constraints.Comment: Submitted for the SUSY07 proceedings, 15 pages, LaTex, 26 eps figure

Written evidence [PTC0018]

The long-term impact of the pandemic on towns and cities. UK Parliament

A multi-objective evolutionary algorithm fitness function for case-base maintenance.

Case-Base Maintenance (CBM) has two important goals. On the one hand, it aims to reduce the size of the case-base. On the other hand, it has to improve the accuracy of the CBR system. CBM can be represented as a multi-objective optimization problem to achieve both goals. Multi-Objective Evolutionary Algorithms (MOEAs) have been recognised as appropriate techniques for multi-objective optimisation because they perform a search for multiple solutions in parallel. In the present paper we introduce a fitness function based on the Complexity Profiling model to perform CBM with MOEA, and we compare its results against other known CBM approaches. From the experimental results, CBM with MOEA shows regularly good results in many case-bases, despite the amount of redundant and noisy cases, and with a significant potential for improvement

Chiral rings, anomalies and loop equations in N=1* gauge theories

We examine the equivalence between the Konishi anomaly equations and the matrix model loop equations in N=1* gauge theories, the mass deformation of N=4 supersymmetric Yang-Mills. We perform the superfunctional integral of two adjoint chiral superfields to obtain an effective N=1 theory of the third adjoint chiral superfield. By choosing an appropriate holomorphic variation, the Konishi anomaly equations correctly reproduce the loop equations in the corresponding three-matrix model. We write down the field theory loop equations explicitly by using a noncommutative product of resolvents peculiar to N=1* theories. The field theory resolvents are identified with those in the matrix model in the same manner as for the generic N=1 gauge theories. We cover all the classical gauge groups. In SO/Sp cases, both the one-loop holomorphic potential and the Konishi anomaly term involve twisting of index loops to change a one-loop oriented diagram to an unoriented diagram. The field theory loop equations for these cases show certain inhomogeneous terms suggesting the matrix model loop equations for the RP2 resolvent.Comment: 23 pages, 3 figures, latex2e, v4: minor changes in introduction and conclusions, 4 references are added, version to appear in JHE

Boson-fermion unification, superstrings, and Bohmian mechanics

Bosonic and fermionic particle currents can be introduced in a more unified way, with the cost of introducing a preferred spacetime foliation. Such a unified treatment of bosons and fermions naturally emerges from an analogous superstring current, showing that the preferred spacetime foliation appears only at the level of effective field theory, not at the fundamental superstring level. The existence of the preferred spacetime foliation allows an objective definition of particles associated with quantum field theory in curved spacetime. Such an objective definition of particles makes the Bohmian interpretation of particle quantum mechanics more appealing. The superstring current allows a consistent Bohmian interpretation of superstrings themselves, including a Bohmian description of string creation and destruction in terms of string splitting. The Bohmian equations of motion and the corresponding probabilistic predictions are fully relativistic covariant and do not depend on the preferred foliation.Comment: 30 pages, 1 figure, revised, to appear in Found. Phy

Equivalence between supersymmetric self-dual and Maxwell-Chern-Simons models coupled to a matter spinor superfield

We study the duality of the supersymmetric self-dual and Maxwell-Chern-Simons theories coupled to a fermionic matter superfield, using a master action. This approach evades the difficulties inherent to the quartic couplings that appear when matter is represented by a scalar superfield. The price is that the spinorial matter superfield represents a unusual supersymmetric multiplet, whose main physical properties we also discuss.Comment: v2, 16 pages, elsarticle.cls, accepted for publication in PL

D=2, N=2, Supersymmetric theories on Non(anti)commutative Superspace

The classical action of a two dimensional N=2 supersymmetric theory, characterized by a general K\"{a}hler potential, is written down on a non(anti)commutative superspace. The action has a power series expansion in terms of the determinant of the non(anti)commutativity parameter $C^{\alpha\beta}$. The theory is explicitly shown to preserve half of the N=2 supersymmetry, to all orders in (det C)^n. The results are further generalized to include arbitrary superpotentials as well.Comment: 32 pages, Latex; v2:minor typos corrected and a reference adde

Low-scale supersymmetry breaking: effective description, electroweak breaking and phenomenology

We consider supersymmetric scenarios in which the scale of SUSY breaking is low, sqrt{F}=O(TeV). Instead of studying specific models of this type, e.g. those with extra dimensions and low fundamental scale, we follow a model-independent approach based on a general effective Lagrangian, in which the MSSM supermultiplets are effectively coupled to a singlet associated to SUSY breaking. Our goal is to analyse the interplay bewteen SUSY breaking and electroweak breaking, generalizing earlier results. The conventional MSSM picture can be substantially modified, mainly because the Higgs potential contains additional effective quartic terms and resembles that of two-Higgs-doublet models, with an additional singlet. Novel opportunities to achieve electroweak breaking arise, and the electroweak scale may be obtained in a less fine-tuned way. Also the Higgs spectrum can be strikingly changed, and the lightest state can be much heavier than in usual supersymmetric scenarios. Other effects appear in the chargino and neutralino sectors, which contain the goldstino. Finally, we discuss the role of electroweak breaking in processes in which two goldstinos could be emitted, such as fermion-antifermion annihilation and the invisible decay of a Z boson or of neutral Higgs bosons.Comment: LaTeX, 47 pages, 5 figures; typos corrected, to appear in Nucl. Phys.

Usefulness of thermography for plant water stress detection in citrus and persimmon trees

[EN] The feasibility of using canopy temperature (Tc) measured with a hand-operated infrared thermographic camera as a water stress indicator was evaluated in the field during two seasons on citrus and persimmon trees subjected to different levels of deficit irrigation. In both species, which differ in leaf anatomy and stomatal response to environmental conditions, Tc was compared with midday stem water potential (s) measurements. In persimmon trees, leaf stomatal conductance (gs) was also measured. In 2009, images were taken from the sunlit and shady sides of the canopies. Based on the results obtained, during the second experimental season images were taken from the sunlit side of the trees and also from above the canopy. In persimmon, trees under deficit irrigation had lower s and gs what resulted in a clear increase in Tc regardless of the position from where the pictures were taken. The maximum Tc difference between deficit-irrigated and control trees observed was of 4.4 ◦C, which occurred when the stressed trees hads values 1.1 MPa lower than the control ones. In persimmon trees, Tc was the most sensitive indicator of plant water status particularly due to the lower tree-to-tree variability as compared to s and gs. On the other hand, in citrus trees Tc was not always affected by plant water stress. Only in the second experimental season, when air vapour pressure deficit values were below 2.7 kPa and images were also taken from above the canopies, deficit-irrigated trees had higher Tc than the control ones, this difference being at most 1.7 ◦C. Overall, the results show that hand-operated thermographic cameras can be used to detect plant water stress in both fruit tree species. Nevertheless, the use of Tc measurements to detect plant water stress appears to be more precise in persimmon than in orange citrus. This might be because persimmon trees have larger leaf size which determines higher canopy resistance allowing for higher increases in canopy temperature in response to water stress via stomatal closure. © 2012 Elsevier B.V. All rights reserved.The authors thank E. Badal, I. Buesa, J. Castel, D. Guerra, D. Perez, F. Sanz and A. Yeves, for their help in field work. This research was supported by funds from projects RIDECO-CONSOLIDER CSD2006-00067, Telerieg Interreg IV Sudoe and "Proyecto Integral Caqui". D.S. Intrigliolo acknowledges the financial support received from the Spanish Ministry of Economy and Competitiveness (MINECO) program "Ramon y Cajal".Ballester, C.; Jiménez Bello, MÁ.; Castel, JR.; Intrigliolo, DS. (2013). Usefulness of thermography for plant water stress detection in citrus and persimmon trees. Agricultural and Forest Meteorology. 168:120-129. https://doi.org/10.1016/j.agrformet.2012.08.005S12012916