12,636 research outputs found
Pion broadening and low-mass dilepton production
We determine mass and transverse momentum spectra of dileptons produced in
Pb+Au (158 GeV/u) collisions within a pion annihilation model.
A fit to the data requires simultaneous mass reduction and broadening of the
in-medium rho propagator.
The introduction of a finite pion width, as required within self-consistent
approaches to the interacting pion gas, further improves the agreement with the
data.Comment: 11 pages, 5 figure
Adiabatic pumping in the quasi-one-dimensional triangle lattice
We analyze the properties of the quasi-one-dimensional triangle lattice
emphasizing the occurrence of flat bands and band touching via the tuning of
the lattice hopping parameters and on-site energies. The spectral properties of
the infinite system will be compared with the transmission through a finite
piece of the lattice with attached semi-infinite leads. Furthermore, we
investigate the adiabatic pumping properties of such a system: depending on the
transmission through the lattice, this results in nonzero integer charge
transfers or transfers that increase linearly with the lattice size
Birth, survival and death of languages by Monte Carlo simulation
Simulations of physicists for the competition between adult languages since
2003 are reviewed. How many languages are spoken by how many people? How many
languages are contained in various language families? How do language
similarities decay with geographical distance, and what effects do natural
boundaries have? New simulations of bilinguality are given in an appendix.Comment: 24 pages review, draft for Comm.Comput.Phys., plus appendix on
bilingualit
Ancient solutions in Lagrangian mean curvature flow
Ancient solutions of Lagrangian mean curvature flow in C^n naturally arise as
Type II blow-ups. In this extended note we give structural and classification
results for such ancient solutions in terms of their blow-down and, motivated
by the Thomas-Yau Conjecture, focus on the almost calibrated case. In
particular, we classify Type II blow-ups of almost calibrated Lagrangian mean
curvature flow when the blow-down is a pair of transverse planes or, when n=2,
a multiplicity two plane. We also show that the Harvey-Lawson Clifford torus
cone in C^3 cannot arise as the blow-down of an almost calibrated Type II
blow-up.Comment: 30 pages, v2: minor typos corrected, accepted in Ann. Sc. Norm.
Super. Pisa Cl. Sc
Partial normalizations of coxeter arrangements and discriminants
We study natural partial normalization spaces of Coxeter arrangements and discriminants
and relate their geometry to representation theory. The underlying ring structures arise from Dubrovin’s
Frobenius manifold structure which is lifted (without unit) to the space of the arrangement. We also
describe an independent approach to these structures via duality of maximal Cohen–Macaulay fractional
ideals. In the process, we find 3rd order differential relations for the basic invariants of the Coxeter
group. Finally, we show that our partial normalizations give rise to new free divisors
Operation of a haynes alloy no. 25 forced circulation loop to study the effects of hydrogen in a simulated sunflower system
Haynes alloy forced circulation mercury loop for studying hydrogen effects in working fluid of Rankine cycle Sunflower solar power syste
Matching Grants and Charitable Giving: Why People Sometimes Provide a Helping Hand to Fund Environmental Goods
Matching grants are a prevalent mechanism for funding environmental, conservation, and natural resource projects. However, economists have largely been silent regarding the potential benefits of these mechanisms at increasing voluntary contributions. To examine the behavioral responses to different match levels, this research uses controlled laboratory experiments with generically framed instructions and introduces a general-form matching-grant mechanism, referred to as the proportional contribution mechanism (PCM). Results show that contributions are positively correlated with both the match and the induced value of the public good even when a dominant strategy is free-riding. An implication of this partial demand revelation result is that manifestations of this type of “helping hand†social preference should be counted in benefit-cost analysis.matching grants, public goods, charitable giving, voluntary contributions, experimental economics, warm glow, helping hand, Environmental Economics and Policy, Public Economics,
Perceived risk and the marginal value of safety.
[Dataset available: http://hdl.handle.net/10411/15662]
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