5,612 research outputs found
Generic dijet soft functions at two-loop order: correlated emissions
We present a systematic algorithm for the perturbative computation of soft
functions that are defined in terms of two light-like Wilson lines. Our method
is based on a universal parametrisation of the phase-space integrals, which we
use to isolate the singularities in Laplace space. The observable-dependent
integrations can then be performed numerically, and they are implemented in the
new, publicly available package SoftSERVE that we use to derive all of our
numerical results. Our algorithm applies to both SCET-1 and SCET-2 soft
functions, and in the current version it can be used to compute two out of
three NNLO colour structures associated with the so-called correlated-emission
contribution. We confirm existing two-loop results for about a dozen
and hadron-collider soft functions, and we obtain new predictions for the
C-parameter as well as thrust-axis and broadening-axis angularities.Comment: 58 pages, 8 figures, associated package can be found at
https://softserve.hepforge.org/. Minor revisio
Rationality in Bargaining by Finite Automata
Aspects of behavioral decision-making can be integrated into game-theoretic models of two-player bargaining using finite automata which can represent bargaining strategies in combination with various behavioral traits. The automata are used as bargaining agents who must jointly agree upon a fixed allocation of transferable utility in an infinite-horizon Rubinstein bargaining game. At each turn, the automata are given the opportunity to accept a proposed portion of the transferable utility, or to reject the proposal and make a counter-offer of their own. A round-robin tournament and ecological simulations were run to explore strategic dominance under different conditions. Principles of bargaining strategy were discussed and future fields of research explored
Rationality in Bargaining by Finite Automata
Aspects of behavioral decision-making can be integrated into game-theoretic models of two-player bargaining using finite automata which can represent bargaining strategies in combination with various behavioral traits. The automata are used as bargaining agents who must jointly agree upon a fixed allocation of transferable utility in an infinite-horizon Rubinstein bargaining game. At each turn, the automata are given the opportunity to accept a proposed portion of the transferable utility, or to reject the proposal and make a counter-offer of their own. A round-robin tournament and ecological simulations were run to explore strategic dominance under different conditions. Principles of bargaining strategy were discussed and future fields of research explored
Long-range quantum entanglement in noisy cluster states
We describe a phase transition for long-range entanglement in a
three-dimensional cluster state affected by noise. The partially decohered
state is modeled by the thermal state of a suitable Hamiltonian. We find that
the temperature at which the entanglement length changes from infinite to
finite is nonzero. We give an upper and lower bound to this transition
temperature.Comment: 7 page
Ofgem RIIO-2 Consultation : Response from the UK Energy Research Centre (UKERC)
The RIIO (Revenue=Incentives+Innovation+Outputs) model, introduced in 2013, is designed to ensure that payments to companies running the gas and electricity transmission and distribution networks are fair to network users and permit the recovery of reasonable costs in developing, maintaining and operating the networks. The network licensees’ allowed revenue is linked to their performance and should therefore offer them incentives for securing investment, driving innovation and delivering the service that customers expect. However, some commentators have suggested that the licensees have been making unjustified profits. With network charges making up around a quarter of the average household energy bill, it is anticipated that the new price control framework will be tougher and provide lower expected returns for network licensees. The RIIO-2 framework consultation is welcome. Ofgem’s final view on price control allowances will be published by the end of 2020 with the new network price controls ('RIIO-2') due to be implemented in 2021. General comments In our submission we responded to the individual points raised in the call. We also note the following: We support the proposal to reduce the price control period from 8 to 5 years. The energy system is undergoing unprecedented change, not only with continued transformation of the generation background but also major changes to the way electricity is used, such as for transport and heating. However, the rate and precise locations of these changes is uncertain. A shorter price control period will provide the opportunity for incentives and cost recovery to be adapted to the changing circumstances. Maintenance of acceptable levels of reliability while facilitating the energy system transformation at least cost requires substantial innovation in technologies, business processes and commercial arrangements. The development of new innovations and associated benefits to consumers often takes years to be realised, sometimes beyond a price control period in which network company shareholders would expect a return. We therefore support the proposal to retain dedicated innovation funding but encourage greater clarity on the scope of activities that can make use of such funding and on best practice in the generation and dissemination of evidence on proposed innovations. We welcome moves to increase the accountability of the network companies and would urge Ofgem to concentrate on those measures that have a genuine and positive impact on the network companies’ activities in the context of the whole energy system. We note that this is not restricted to the business plans submitted under RIIO-2 but extends to a whole raft of codes and interactions. These include the evolving responsibilities of the Electricity System Operator (ESO), the relationships between the ESO, the transmission owners and the Distribution Network Operators, and the processes for ensuring that the full set of codes, standards and market arrangements are coherent and fit for purpose. This is a challenging task that requires constant attention to ‘the big picture’ and sufficient resources, commitment and expertise on the part of the network owners, system operators and Ofgem. In applying tighter controls that avoid excessive returns to the network licensees’ owners, the upside and downside risks should be clearly assessed and incentives for managing risk placed on those parties best placed to do so
Automated Calculation of Dijet Soft Functions in the Presence of Jet Clustering Effects
We extend our framework for the automated calculation of dijet soft functions
to observables that do not obey the non-Abelian exponentiation theorem, like
jet-veto or grooming soft functions that are sensitive to clustering effects of
the jet algorithm. Although the matrix element for uncorrelated double
emissions has a simpler structure than the one for correlated emissions, we
argue that its singularity structure poses more stringent constraints on the
required phase-space parametrisation. Our algorithm applies to both SCET-1 and
SCET-2 soft functions and it is implemented in the novel program SoftSERVE. We
present results for various jet-veto observables and obtain new predictions for
the soft-drop jet-grooming algorithm.Comment: 7 pages, 3 figures; to appear in the proceedings of the 13th
International Symposium on Radiative Corrections (Radcor 2017), 24-29
September 2017, St. Gilgen, Austri
Heavy drinking days and mental health: an exploration of the dynamic 10-year longitudinal relationship in a prospective cohort of untreated heavy drinkers.
BACKGROUND: Identifying dominant processes that underlie the development of other processes is important when evaluating the temporal sequence between disorders. Such information not only improves our understanding of etiology but also allows for effective intervention strategies to be tailored. The temporal relationship between alcohol intake and mental health remains poorly understood, particularly in nonclinical samples. The purpose of this study was to disentangle the dominant temporal sequence between mental health and frequency of heavy drinking days. METHODS: We report a 10-year (1997 to 2007) prospective cohort study of 500 respondents (74% male) from the Birmingham Untreated Heavy Drinkers project. Participants were aged 25 to 55 years at baseline, drinking a minimum of 50/35 U.K. units of alcohol for men/women on a weekly basis, and were not seeking treatment for their alcohol use upon recruitment into the study. Heavy drinking days were defined as consuming 10/7+ U.K. units of alcohol in a single day for men/women. Mental health was assessed using the mental health component score of the SF-36 questionnaire. Dynamic longitudinal structural equation models were used to test competing theoretical models (frequency of heavy drinking days leading to changes in mental health scores and vice versa) and a reciprocal relationship (both mental health scores and the frequency of heavy drinking days influencing changes in each other). RESULTS: A model whereby mental health scores were predictors of change in the frequency of heavy drinking days was of best fit. In this model, mental health scores were negatively related to change in heavy drinking days (β -0.80, SE 0.28) indicating that those with higher mental health scores (i.e., better functioning) made larger reductions in the number of heavy drinking days over time. CONCLUSIONS: Mental health appears to be the stronger underlying process in the relationship between mental health and frequency of heavy drinking days
Mapping the optical absorption of a substrate-transferred crystalline AlGaAs coating at 1.5 µm
The sensitivity of 2nd and 3rd generations of interferometric gravitational wave detectors will be limited by thermal noise of the test-mass mirrors and highly reflective coatings. Recently developed crystalline coatings show a promising thermal noise reduction compared to presently used amorphous coatings. However, stringent requirements apply to the optical properties of the coatings as well. We have mapped the optical absorption of a crystalline AlGaAs coating which is optimized for high reflectivity for a wavelength of 1064nm. The absorption was measured at 1550nm where the coating stack transmits approximately 70% of the laser light. The measured absorption was lower than (30.2 +/- 11.1)ppm which is equivalent to (3.6 +/- 1.3)ppm for a coating stack that is highly reflective at 1530nm. While this is a very promising low absorption result for alternative low--loss coating materials, further work will be necessary to reach the requirements of <1ppm for future gravitational wave detectors.
Jessica Steinlechner, Iain W Martin, Angus Bell, Garrett Cole, Jim Hough, Steven Penn, Sheila Rowan, Sebastian Steinlechne
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