Topflavor: A Separate SU(2) for the Third Family

We consider an extended electroweak gauge group: SU(2)$_1 \times$ SU(2)$_2 \times$ U(1)$_Y$ where the first and second generation of fermions couple to SU(2)$_1$ and the third generation couples to SU(2)$_2$. Bounds based on heavy gauge boson searches and current precision electroweak measurements are placed on the masses of the new heavy gauge bosons. In particular we find that the mass of the heavy W boson can not be less than 800 GeV. For some range of the allowed parameter space, these heavy gauge bosons produce observable signals at the Tevatron and LEP-II.Comment: LaTeX, 11 pages, some comments on FCNC interactions and single top production added, additional references include

Tradeoffs from hedging oil pricerisk in Ecuador

The oil sector is critical to Ecuador's economy, contributing about 17 percent to the country's GDP. Ecuador began exporting crude oil in 1972 and over the past two and a half decades oil has become the country's most important sector. It is controlled by the government through the public enterprise, PETROECUADOR, which serves as the holding company for all state-owned petroleum operations. Movements in oil prices are of major concern to the government, and forecasts of oil prices are built into the government budget. Ecuador's macroeconomic performance depends on the oil sector's performance; shocks to the sector have economywide repercussions. The authors investigate methods to reduce risk for the country's oil exports through hedging in futures markets. They find that hedging Ecuadorian oil has significant potential for risk reduction. After simulating ex-ante cross hedges for 1991-96, they find that in each case ex-ante hedging effectively reduces risk. They calculate the tradeoffs between return and risk from hedging and find that for a risk-minimizing short hedger, a 1-percent reduction in risk would cost a reduction in return of 0.65 percent.International Terrorism&Counterterrorism,Payment Systems&Infrastructure,Environmental Economics&Policies,Economic Theory&Research,Non Bank Financial Institutions,Environmental Economics&Policies,Economic Theory&Research,Insurance&Risk Mitigation,Non Bank Financial Institutions,Health Economics&Finance

Single Kaluza Klein Production in Universal Extra Dimensions

In the universal extra dimensions models, Kaluza Klein excitations of matter are generaly produced in pairs. However, if matter lives on a fat brane embedded in a larger space, gravity-matter interactions do not obey KK number conservation, thus making possible the production of single KK excitations at colliders. We evaluate the production rates for such excitations at the Tevatron and LHC colliders, and look for ways to detect them.Comment: 11 pages, 6 figures, late

Dilepton and Four-Lepton Signals at the LHC in the Littlest Higgs Model with T-parity Violation

In the presence of the T-parity violating Wess-Zumino-Witten (WZW) anomaly term, the otherwise stable heavy photon A_H in the Littlest Higgs model with T-parity (LHT) decays to either Standard Model (SM) gauge boson pairs, or to SM fermions via loop diagrams. We make a detailed study of the collider signatures where the A_H can be reconstructed from invariant mass peaks in the opposite sign same flavor dilepton or the four-lepton channels. This enables us to obtain information about the fundamental symmetry breaking scale f in the LHT and thereby the low-lying mass spectrum of the theory. In addition, indication of the presence of the WZW term gives us hints of the possible UV completion of the LHT via strong dynamics. The crucial observation is that the sum of all production processes of heavy T-odd quark pairs has a sizeable cross-section at the LHC and these T-odd particles eventually all cascade decay down to the heavy photon A_H. We show that for certain regions of the parameter space with either a small f of around 500 GeV or relatively light T-odd quarks with a mass of around 400 GeV, one can reconstruct the A_H even at the early LHC run with \sqrt{s}=10 TeV and a modest integrated luminosity of 200 pb^{-1}. At \sqrt{s} = 14 TeV and with an integrated luminosity of 30 fb^{-1}, it is possible to cover a large part of the typical parameter space of the LHT, with the scale f up to 1.5 TeV and with T-odd quark masses almost up to 1 TeV. In this region of the parameter space, the mass of the reconstructed A_H ranges from 66 GeV to 230 GeV.Comment: 35 pages, 4 figures; v2: additional multiple hard jets included in background simulation using ALPGEN, main conclusions unchanged, references added, version as published in JHEP

Same-sign trileptons and four-leptons as signatures of new physics at the Large Hadron Collider

We point out that same-sign multilepton events, not given due attention yet for new physics search, can be extremely useful at the Large Hadron Collider. After showing the easy reducibility of the standard model backgrounds, we demonstrate the viability of same-sign trilepton signals for R-parity breaking supersymmetry, at both 7 and 14 TeV. We find that same-sign four-leptons, too, can have appreciable rates. Same-sign trileptons are also expected, for example, in Little Higgs theories with T-parity broken by anomaly terms.Comment: 5 pages, 1 figure; v2: minor additions to text, references added, version to appear in Physical Review D (Rapid Communications

An efficient frontier for international portfolios with commodity assets

In recent years, the role of investment funds has increased in most commodity markets. Investment funds, which traditionally deal with financial markets, have been shifting between financial markets and commodity futures markets, as well as among commodity futures markets. The popularity of investing in emerging capital markets is as high as it has been since World War I. By 1913, nearly half of a typical equity portfolio was invested in emerging markets. Today, one in every four dollars invested in foreign equity markets goes to emerging markets. Both commodity futures and emerging capital markets are growing in popularity because they allow risk reductionthrough portfolio diversification. The authors analyze the benefits of including commodity futures and assets from emerging markets in an investment portfolio. They also try to calculate the optimal composition of assets. The calculated optimal weights show that a considerable proportion of an investment portfolio could be invested in commodity futures and emerging market assets. The weights calculated are higher than those funds usually used, signifying the potential for futher expansion of these assets in a portfolio. Finally, including commodity futures and assets from emerging markets in investment portfolios produces a significant risk/return benefit.Economic Theory&Research,International Terrorism&Counterterrorism,Insurance Law,Financial Intermediation,Markets and Market Access