17,899 research outputs found
Rare b hadron decays at the LHC
With the completion of Run~I of the CERN Large Hadron Collider, particle
physics has entered a new era. The production of unprecedented numbers of
heavy-flavoured hadrons in high energy proton-proton collisions allows detailed
studies of flavour-changing processes. The increasingly precise measurements
allow to probe the Standard Model with a new level of accuracy. Rare hadron
decays provide some of the most promising approaches for such tests, since
there are several observables which can be cleanly interpreted from a
theoretical viewpoint. In this article, the status and prospects in this field
are reviewed, with a focus on precision measurements and null tests.Comment: Invited review for Annual Reviews of Nuclear and Particle Physics. v2
as publishe
The molecular emission-line spectrum of IRC +10216 between 330 and 358 GHz
We have conducted a spectral line survey of IRC + 10216 using the Caltech Submillimeter Observatory to an
average sensitivity of ≾95 mK. A deconvolution algorithm has been used to derive the continuous single-sideband
spectrum from 330.2 to 358.1 GHz. A total of 56 spectral lines were detected of which 54 have been identified
with 8 molecules and a total of 18 isotopomers. The observed lines are used to derive column densities and relative abundances for the detected species. Within this frequency range the spectral lines detected contribute the majority of the total flux emitted by IRC + 10216. We use the derived column densities and excitation temperatures to
simulate the molecular line emission (assuming LTE) at frequencies up to 1000 GHz. The observed and simulated
flux from line emission is compared to broadband total flux measurements and to dust emission assuming a power-law variation of the dust emissivity. We conclude that significant corrections for the line flux must be made
to broadband flux measurements of IRC + 10216 at wavelengths longer than ~750 µm
Emissions of Volatile Organic Compounds Inferred From Airborne Flux Measurements over a Megacity
Toluene and benzene are used for assessing the ability to measure disjunct eddy covariance (DEC) fluxes of Volatile Organic Compounds (VOC) using Proton Transfer Reaction Mass Spectrometry (PTR-MS) on aircraft. Statistically significant correlation between vertical wind speed and mixing ratios suggests that airborne VOC eddy covariance (EC) flux measurements using PTR-MS are feasible. City-median midday toluene and benzene fluxes are calculated to be on the order of 14.1&plusmn;4.0 mg/m<sup>2</sup>/h and 4.7&plusmn;2.3 mg/m<sup>2</sup>/h, respectively. For comparison the adjusted CAM2004 emission inventory estimates toluene fluxes of 10 mg/m<sup>2</sup>/h along the footprint of the flight-track. Wavelet analysis of instantaneous toluene and benzene measurements during city overpasses is tested as a tool to assess surface emission heterogeneity. High toluene to benzene flux ratios above an industrial district (e.g. 10–15 g/g) including the International airport (e.g. 3–5 g/g) and a mean flux (concentration) ratio of 3.2&plusmn;0.5 g/g (3.9&plusmn;0.3 g/g) across Mexico City indicate that evaporative fuel and industrial emissions play an important role for the prevalence of aromatic compounds. Based on a tracer model, which was constrained by BTEX (BTEX– Benzene/Toluene/Ethylbenzene/m, p, o-Xylenes) compound concentration ratios, the fuel marker methyl-tertiary-butyl-ether (MTBE) and the biomass burning marker acetonitrile (CH<sub>3</sub>CN), we show that a combination of industrial, evaporative fuel, and exhaust emissions account for >87% of all BTEX sources. Our observations suggest that biomass burning emissions play a minor role for the abundance of BTEX compounds in the MCMA (2–13%)
"I want to be an Educational Psychologist": Aspiring Trainee Educational Psychologists’ Perceptions of the Course Application Process
This thesis explored aspiring Trainee Educational Psychologists’ (A-TEPs’) experiences of the Association of Education Psychologists’ (AEP) professional doctorate (ProfDoc) application process. The number of A-TEP applications to the Educational Psychology ProfDoc providers has increased steadily over time, however, the absence of literature about this process suggests there is limited knowledge about A-TEPs’ experiences of applying to become Trainee Educational Psychologists (TEPs). Whilst position papers about the journey of aspiring Clinical Psychologists and empirical evidence from New Zealand suggest the process is stressful, nothing is known about how A-TEPs experience the AEP’s application process.
Within this sequential Mixed methods research, 110 participants responded to an online 19-item questionnaire in the quantitative phase. Descriptive and inferential statistics captured information about the sources of support and highlighted aspirants experience the process pleasantly. In the qualitative phase, six informants shared their thoughts, feelings and events which occurred throughout the process via narrative interviews. Narrative analysis was used as a method to explore these stories. Discussion of the findings suggest that although the application process was deemed stressful and negative experience increased as it progressed, the overall application process was experienced positively. With regards to sources of support, interaction with Educational Psychologists (EPs) was most useful and exploration of the AEP and universities’ websites were most common. Novel findings about the social support of family and online communities were found from the data. By contrast, the naïve enquiries of those who did not understand the process and ‘group panic’ found in forums were deemed unhelpful.
The researcher suggests further research exploration into the voices of minority groups of A-TEPs’ is important. Possible implications for EPs, course providers and the AEP suggest there are systemic changes these bodies could make to further enhance the pleasant experiences of future A-TEPs
Comparison of submillimeter and ultraviolet observations of neutral carbon toward Zeta Ophiuchi
We have observed the ^3P_1 → ^3P_0 ground state transition of C_I emission toward ζ Oph. We compare this observation with predictions made from Copernicus ultraviolet absorption measurements of the population of the ^3P_1 level and with millimeter wave observations of CO
Hierarchical Bayesian Modeling of Hitting Performance in Baseball
We have developed a sophisticated statistical model for predicting the
hitting performance of Major League baseball players. The Bayesian paradigm
provides a principled method for balancing past performance with crucial
covariates, such as player age and position. We share information across time
and across players by using mixture distributions to control shrinkage for
improved accuracy. We compare the performance of our model to current
sabermetric methods on a held-out season (2006), and discuss both successes and
limitations
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