HR Analytics: Talent Acquisition

[Excerpt] HR Analytics is becoming increasingly important as new technologies, software and new methods of data collection are revolutionizing the HR function. One area in which analytics tools are particularly flourishing is the talent acquisition space. With an increasingly competitive talent market, talent acquisition presents itself as an area in which analytics tools can greatly supplement decision making for these 3 reasons: here are many measurable, verifiable metrics to measure in terms of sources of talent, candidate qualifications, and the efficacy of the recruitment process here is an abundance of sources from which to collect data (Online sources, interviews, etc.) With the increased importance of sourcing the correct talent, the opportunity to use analytics tools to make better decisions is quite compelling Given these reasons, talent acquisition presents itself as an opportunity for organizations to build their analytics capabilities while driving measurable business outcomes and improvements to their organization. As evidenced in the above graphic, many organizations are already undertaking these changes or considering changes in the near future

Recent results of the STAR high-energy polarized proton-proton program at RHIC at BNL

The STAR experiment at the Relativistic Heavy-Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) is carrying out a spin physics program colliding transverse or longitudinal polarized proton beams at $\sqrt{s}=200-500$GeV to gain a deeper insight into the spin structure and dynamics of the proton. These studies provide fundamental tests of Quantum Chromodynamics (QCD). One of the main objectives of the STAR spin physics program is the determination of the polarized gluon distribution function through a measurement of the longitudinal double-spin asymmetry, $A_{LL}$, for various processes. Recent results will be shown on the measurement of $A_{LL}$ for inclusive jet production, neutral pion production and charged pion production at $\sqrt{s}=200$GeV. In addition to these measurements involving longitudinal polarized proton beams, the STAR collaboration has performed several important measurements employing transverse polarized proton beams. New results on the measurement of the transverse single-spin asymmetry, $A_{N}$, for forward neutral pion production and the first measurement of $A_{N}$ for mid-rapidity di-jet production will be discussed.Comment: 8 pages, 5 figures, Invited talk given at the 17th International Spin Physics Symposium (SPIN 2006), October 2006, Kyoto, Japa

Selected results on Strong and Coulomb-induced correlations from the STAR experiment

Using recent high-statistics STAR data from Au+Au and Cu+Cu collisions at full RHIC energy I discuss strong and Coulomb-induced final state interaction effects on identical ($\pi-\pi$) and non-identical ($\pi-\Xi$) particle correlations. Analysis of $\pi-\Xi$ correlations reveals the strong and Coulomb-induced FSI effects allowing for the first time to estimate space extension of $\pi$ and $\Xi$ sources and average shift between them. Source imaging technique providing clean separation of these effects from effects due to the source function itself is applied to one-dimensional relative momentum correlation function of identical pions. For low momentum pions and/or non-central collisions large departure from a single-Gaussian shape is observed

Longitudinal Spin Asymmetry and Cross Section of Inclusive pi0 Production in Polarized p+p Collisions at RHIC

We present the first measurement of the cross section and the double longitudinal spin asymmetry of inclusive pi0 production in polarized p+p collisions at Sqrt(s) = 200 GeV at mid-rapidity with the STAR detector, using the barrel electromagnetic calorimeter. The measured cross section is compared to NLO pQCD calculations and can provide constraints on the pion fragmentation functions. Fragmentation is studied directly by measuring the momentum fraction of pi0 in jets, a quantity that is affected by the fragmentation process and jet reconstruction effects. The double longitudinal spin asymmetry is compared to NLO pQCD calculations based on different assumptions for the gluon polarization in the nucleon to provide constraints on delta g/g. At the present level of statistics the measured asymmetry disfavors a large positive gluon polarization, but can not yet distinguish between other scenarios.Comment: 4 pages, 2 figures, submitted to the proceedings of the 17th International Spin Physics Symposium (SPIN2006), Kyoto, Japan, October 2 to 7, 200

Measurements of Transverse Spin Effects with the Forward Pion Detector of STAR

Measurements by the STAR collaboration of neutral pion production at large Feynman x (x_F) in the first polarized proton collisions at $\sqrt{s}=200$ GeV were reported previously. Cross sections measured at $\eta=3.3$, 3.8 and 4.0 are found to be consistent with next-to-leading order perturbative QCD calculations. The analyzing power is consistent with zero at negative x_F and at positive x_F up to ~0.3, then grows more positive with increasing x_F. This behavior can be described by phenomenological models including the Sivers effect, the Collins effect or higher twist contributions in the initial and final states. Forward calorimetry at STAR has been extended, and there are plans for further expansion. An integrated luminosity of 6.8 pb^${-1}$ with average beam polarization of 60% from online polarimetry measurements was sampled with the upgraded FPD in the 2006 RHIC run. This data sample will allow for a detailed map of the \pi^0 analyzing power over kinematic variables bounded by 0.3 < x_F < 0.6 and 1.2 < p_T < 5.0 GeV/c at $\sqrt{s}=200$ GeV. The expanded FPD has observed multi-photon final states expected to have "jet-like" characteristics. The transverse spin dependence of jet-like events can discriminate between the Collins and Sivers effects and lead to further progress in understanding the origin of single spin asymmetries in forward particle production. Data were also obtained at $\sqrt{s}=62.4$ GeV for x_F -> 1 to test predictions based on phenomenological fits to earlier STAR results. Recent results, the status of the analysis of 2006 run data and near-term plans will be discussed.Comment: 4 pages, 3 figures, to be published in the proceedings of the 17th International Spin Physics Symposium (SPIN2006), October 2-7, 2006, Kyoto, Japa

Measurement of Sivers Asymmetries for Di-jets in \sqrt{s}=200 GeV pp Collisions at STAR

Measurement of the transverse spin dependence of the di-jet opening angle in pp collisions at sqrt{s}=200 GeV has been performed by the STAR collaboration. An analyzing power consistent with zero has been observed over a broad range in pseudorapidity sum of the two jets with respect to the polarized beam direction. A non-zero (Sivers) correlation between transverse momentum direction of partons in the initial state and transverse spin orientation of the parent proton has been previously observed in semi-inclusive deep inelastic scattering (SIDIS). The present measurements are much smaller than deduced from predictions made for STAR di-jets based on non-zero quark Sivers functions deduced from SIDIS, and furthermore indicate that gluon Sivers asymmetries are comparably small.Comment: 4 pages, 3 figures, talk presented at SPIN 2006, Kyoto, October 200

Longitudinal Double Spin Asymmetry in Inclusive Jet Production at STAR

This contribution reports on the first measurement of the longitudinal double-spin asymmetry $A_{LL}$ for the inclusive production of jets in polarized proton-proton collisions at $\sqrt{s}=200 \mathrm{GeV}$. The data were collected with STAR at RHIC in the years 2003 and 2004, and correspond to a sampled integrated luminosity of $0.3 \mathrm{pb}^{-1}$ with beam polarizations up to 45%. The results on $A_{LL}$ cover jet transverse momenta $5 < p_{T} < 17 \mathrm{GeV/c}$ and agree with perturbative QCD evaluations based on deep-inelastic scattering parametrizations for the gluon polarization in the proton. The results disfavor large positive gluon polarization in the polarized proton.Comment: 5 pages, 1 figur

New Challenges to Hydrodynamics from Azimuthal Anisotropy at RHIC

This paper presents $v_{4}/v_{2}^2$ ratio as a function of transverse momentum ($p_{t}$), pseudorapidity ($\eta$) and collision centrality in Au+Au collisions at $\sqrt{s_{NN}} = 200$ GeV using the STAR detector at the Relativistic Heavy Ion Collider (RHIC). It is found that $v_{4}/v_{2}^2$ is larger than Hydrodynamic calculations, the centrality and transverse dependence of this ratio can not be fully described by Hydrodynamics, and the pseudorapidity dependence is opposite to what one expects from Hydrodynamics. The $p_{t}$ dependence of $v_{1}$ is also presented. It is found that $v_{1}(p_{t})$ for $|\eta|<1.3$ changes sign, and two possible explanations of the sign change are discussed.Comment: 4 pages, 3 figures. CIPANP 06 proceedin

An Integrated Tracker for STAR

The STAR experiment at the Relativistic Heavy Ion Collider RHIC studies the new state of matter produced in relativistic heavy ion collisions and the spin structure of the nucleon in collisions of polarized protons. In order to improve the capabilities for heavy flavor measurements and the reconstruction of charged vector bosons an upgrade of the tracking system both in the central and the forward region is pursued. The integrated system providing high resolution tracking and secondary vertex reconstruction capabilities will use silicon pixel, strip and GEM technology.Comment: 4 pages, 2 figures, to be published in the Proceedings of the 9th Conference on the Intersections of Particle and Nuclear Physics (CIPANP 2006), Rio Grande, Puerto Rico, May 30 - June 3, 200

Energy and system size dependence of elliptic flow: using rapidity gaps to suppress non-flow contribution

In this talk I present new STAR results on measurements of integrated elliptic flow at midrapidity in Au+Au and Cu+Cu collisions at $\sqrt{s_{NN}}=$200 and 62 GeV energies. These results have been obtained from azimuthal correlations between particles in the main STAR TPC and two forward TPCs, and are to a large extent free from so-called non-flow correlations. These results along with the previously reported values of ``participant'' eccentricity taking into account eccentricity fluctuations are used for testing the v_2/\eps scaling, which is found to hold relatively well.Comment: 4 pages. Talk at CIPANP 2006, 9th Conference on the Intersections of Particle and Nuclear Physics, May 30-June 3, 2006, Rio Grande, Puerto Ric