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Price Destabilizing Speculation
It is sometimes asserted that rational speculative activity must result in more stable prices because speculators buy when prices are low and sell when they are high. This is incorrect. Speculators buy when the chances of price appreciation are high, selling when the chances are low. Speculative activity in an economy in which all agents are rational, have identical priors, and have access to identical information may destabilize prices, under any reasonable definition of destabilization. It takes extremely strong conditions to ensure that speculative activity (of the commodity storage variety) "stabilizes" prices, even in a very weak sense.Economic
Identifying Behavioral Differences Between People With and Without Previous Cancer Diagnosis
We undertake a study to determine and assess the effects of the statistically significant predictors of the behaviors and notions that are associated with a cancer diagnosis using the 2014 Health Information National Trends Survey (HINTS) data. We implemented a new and extensive logistic regression modeling using stepwise variable selection and jackknife parameter estimation that identified the best explanatory model. Our results show that age, average time spent watching TV or playing games, usage of sunscreen, fruit intake intent, and the opinion-based variables for behaviors affecting high blood pressure, as well as the participant preference of not knowing the chance of getting cancer are the optimal set of covariates impacting the chance of getting cancer. Moreover, using more sunscreen, and a higher age was associated with increases in the chances of getting cancer. Interestingly, many usually important background covariates such as race, income, gender, geographical location, and others were not significant predictors of the outcome variable of interest. The conclusions of our analysis reveal new insights in the complexity of the behaviors and āattitudesā associated with a higher chance of a cancer diagnosis and will undoubtedly have important implications on the design and success of future healthcare messages and campaigns
Statistical mechanics of systems with heterogeneous agents: Minority Games
We study analytically a simple game theoretical model of heterogeneous
interacting agents. We show that the stationary state of the system is
described by the ground state of a disordered spin model which is exactly
solvable within the simple replica symmetric ansatz. Such a stationary state
differs from the Nash equilibrium where each agent maximizes her own utility.
The latter turns out to be characterized by a replica symmetry broken
structure. Numerical results fully agree with our analytic findings.Comment: 4 pages, 1 Postscript figure. Revised versio
A model-independent Dalitz plot analysis of BĀ±āDKĀ± with DāK0Sh+hā (h=Ļ,K) decays and constraints on the CKM angle Ī³
A binned Dalitz plot analysis of B Ā±āDK Ā± decays, with DāKS0Ļ+Ļ- and DāKS0K+K-, is performed to measure the CP-violating observables x Ā± and y Ā± which are sensitive to the CKM angle Ī³. The analysis exploits 1.0 fb -1 of data collected by the LHCb experiment. The study makes no model-based assumption on the variation of the strong phase of the D decay amplitude over the Dalitz plot, but uses measurements of this quantity from CLEO-c as input. The values of the parameters are found to be x -=(0.0Ā±4.3Ā±1.5Ā±0.6)Ć10 -2, y -=(2.7Ā±5.2Ā±0.8Ā±2.3)Ć10 -2, x +=(-10.3Ā±4.5Ā±1.8Ā±1.4)Ć10 -2 and y +=(-0.9Ā±3.7Ā±0.8Ā±3.0)Ć10 -2. The first, second, and third uncertainties are the statistical, the experimental systematic, and the error associated with the precision of the strong-phase parameters measured at CLEO-c, respectively. These results correspond to Ī³=(44-38+43)Ā°, with a second solution at Ī³āĪ³+180Ā°, and r B=0.07Ā±0.04, where r B is the ratio between the suppressed and favoured B decay amplitudes
Absolute luminosity measurements with the LHCb detector at the LHC
Absolute luminosity measurements are of general interest for colliding-beam experiments at storage rings. These measurements are necessary to determine the absolute cross-sections of reaction processes and are valuable to quantify the performance of the accelerator. Using data taken in 2010, LHCb has applied two methods to determine the absolute scale of its luminosity measurements for proton-proton collisions at the LHC with a centre-of-mass energy of 7 TeV. In addition to the classic ''van der Meer scan'' method a novel technique has been developed which makes use of direct imaging of the individual beams using beam-gas and beam-beam interactions. This beam imaging method is made possible by the high resolution of the LHCb vertex detector and the close proximity of the detector to the beams, and allows beam parameters such as positions, angles and widths to be determined. The results of the two methods have comparable precision and are in good agreement. Combining the two methods, an overal precision of 3.5% in the absolute luminosity determination is reached. The techniques used to transport the absolute luminosity calibration to the full 2010 data-taking period are presented
First observation of the decay B0sāĻKā0
The first observation of the decay B0sāĻKā0 is reported. The analysis is based on a data sample corresponding to an integrated luminosity of 1.0 fbā1 of pp collisions at sā=7 TeV, collected with the LHCb detector. A yield of 30 Ā± 6 B0sā(K+Kā)(KāĻ+) decays is found in the mass windows 1012.5 < M (K + K ā) < 1026.5 MeV/c 2 and 746 < M(K ā Ļ +) < 1046 MeV/c 2. The signal yield is found to be dominated by B0sāĻKā0 decays, and the corresponding branching fraction is measured to be B(B0sāĻKā0) = (1.10 Ā± 0.24 (stat) Ā± 0.14 (syst) Ā± 0.08 (f d /f s )) Ć 10ā6, where the uncertainties are statistical, systematic and from the ratio of fragmentation fractions f d /f s which accounts for the different production rate of B 0 and B0s mesons. The significance of B0sāĻKā0 signal is 6.1 standard deviations. The fraction of longitudinal polarization in B0sāĻKā0 decays is found to be f 0 = 0.51 Ā± 0.15 (stat) Ā± 0.07 (syst)
Observation of the suppressed ADS modes BĀ± ā [ĻĀ±K-/+ Ļ+Ļ-]D KĀ± and BĀ± ā [ĻĀ± K-/+Ļ+Ļ-]DĻĀ±
An analysis of and BĀ± ā DKĀ± and BĀ± ā DĻĀ±
decays is presented where the D meson is reconstructed in the four-body final state KĀ± Ļ-/+Ļ+Ļ-. Using LHCb data corresponding to an integrated luminosity of 1.0 fb-1, first observations are made of the suppressed ADS modes BĀ± ā[ĻĀ± K-/+Ļ+Ļ-]DKĀ± and BĀ± ā [ĻĀ± K-/+Ļ+Ļ-]DĻĀ± with a significance of 5.1 sigma and greater than 10 sigma, respectively. Measurements of CP asymmetries and CP-conserving ratios of partial widths from this family of decays are also performed. The magnitude of the ratio between the suppressed and favoured BĀ± ā DK Ā± amplitudes is determined to be rKB = 0.097 Ā± 0.011
First evidence of direct CP violation in charmless two-body decays of Bs0 mesons
Using a data sample corresponding to an integrated luminosity of 0.35āāfb-1 collected by LHCb in 2011, we report the first evidence of CP violation in the decays of Bs0 mesons to KĀ±Ļā pairs, ACP(Bs0āKĻ)= 0.27Ā±0.08(stat)Ā±0.02(syst), with a significance of 3.3Ļ. Furthermore, we report the most precise measurement of CP violation in the decays of B0 mesons to KĀ±Ļā pairs, ACP(B0āKĻ)=-0.088Ā±0.011(stat)Ā±0.008(syst), with a significance exceeding 6Ļ
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