Twistor Strings with Flavour

We explore the tree-level description of a class of N=2 UV-finite SYM theories with fundamental flavour within a topological B-model twistor string framework. In particular, we identify the twistor dual of the Sp(N) gauge theory with one antisymmetric and four fundamental hypermultiplets, as well as that of the SU(N) theory with 2N hypermultiplets. This is achieved by suitably orientifolding/orbifolding the original N=4 setup of Witten and adding a certain number of new topological 'flavour'-branes at the orientifold/orbifold fixed planes to provide the fundamental matter. We further comment on the appearance of these objects in the B-model on CP(3|4). An interesting aspect of our construction is that, unlike the IIB description of these theories in terms of D3 and D7-branes, on the twistor side part of the global flavour symmetry is realised geometrically. We provide evidence for this correspondence by calculating and matching amplitudes on both sides.Comment: 38+12 pages; uses axodraw.sty. v2: References added, minor clarification

Measurement of the Charged Multiplicities in b, c and Light Quark Events from Z0 Decays

Average charged multiplicities have been measured separately in $b$, $c$ and light quark ($u,d,s$) events from $Z^0$ decays measured in the SLD experiment. Impact parameters of charged tracks were used to select enriched samples of $b$ and light quark events, and reconstructed charmed mesons were used to select $c$ quark events. We measured the charged multiplicities: $\bar{n}_{uds} = 20.21 \pm 0.10 (\rm{stat.})\pm 0.22(\rm{syst.})$, $\bar{n}_{c} = 21.28 \pm 0.46(\rm{stat.}) ^{+0.41}_{-0.36}(\rm{syst.})$ $\bar{n}_{b} = 23.14 \pm 0.10(\rm{stat.}) ^{+0.38}_{-0.37}(\rm{syst.})$, from which we derived the differences between the total average charged multiplicities of $c$ or $b$ quark events and light quark events: $\Delta \bar{n}_c = 1.07 \pm 0.47(\rm{stat.})^{+0.36}_{-0.30}(\rm{syst.})$ and $\Delta \bar{n}_b = 2.93 \pm 0.14(\rm{stat.})^{+0.30}_{-0.29}(\rm{syst.})$. We compared these measurements with those at lower center-of-mass energies and with perturbative QCD predictions. These combined results are in agreement with the QCD expectations and disfavor the hypothesis of flavor-independent fragmentation.Comment: 19 pages LaTex, 4 EPS figures, to appear in Physics Letters

Carbon emissions from the commercial building sector: The Role of climate, quality, and incentives

Commercial buildings play a major role in determining U.S. greenhouse gas emissions, yet surprisingly little is known about the environmental performance of different buildings at a point in time or how the same buildings perform over time. By exploiting a unique panel of commercial buildings from a major electric utility, we study the association between a building's electricity consumption and the physical attributes of buildings, lease incentive terms, indicators of human capital, and climatic conditions. We find that buildings that are newer and of higher quality consume more electricity, contrasting evidence for the residential sector. However, using our panel data set, we document that newer buildings are most resilient when exposed to hotter weather. Those buildings that have a building manager on-site and whose tenants face a positive marginal cost for electricity also demonstrate a better environmental performance. (C) 2014 Elsevier B.V. All rights reserved

Endocrine assessment of impotence--pitfalls of measuring serum testosterone without sex-hormone-binding globulin.

The pitfalls of measuring only total serum testosterone are illustrated by a 52 year old man whose hyperprolactinaemia was associated with normal total serum testosterone but a raised sex-hormone-binding globulin, giving a low free testosterone. Prolactin suppression with bromocriptine normalized sex-hormone-binding globulin and free testosterone, and restored potency and energy after 30 years of impotence and tiredness