Showing papers by "A. V. Alakhverdyants published in 2010"

Observation of charge-dependent azimuthal correlations and possible local strong parity violation in heavy-ion collisions

Abstract: Parity (P)-odd domains, corresponding to nontrivial topological solutions of the QCD vacuum, might be created during relativistic heavy-ion collisions. These domains are predicted to lead to charge separation of quarks along the orbital momentum of the system created in noncentral collisions. To study this effect, we investigate a three-particle mixed-harmonics azimuthal correlator which is a P-even observable, but directly sensitive to the charge-separation effect. We report measurements of this observable using the STAR detector in Au + Au and Cu + Cu collisions at root s(NN) = 200 and 62 GeV. The results are presented as a function of collision centrality, particle separation in rapidity, and particle transverse momentum. A signal consistent with several of the theoretical expectations is detected in all four data sets. We compare our results to the predictions of existing event generators and discuss in detail possible contributions from other effects that are not related to P violation.

Higher moments of net proton multiplicity distributions at RHIC.

Abstract: 200 GeV corresponding to baryon chemical potentials (mu(B)) between 200 and 20 MeV. Our measurements of the products kappa sigma(2) and S sigma, which can be related to theoretical calculations sensitive to baryon number susceptibilities and long-range correlations, are constant as functions of collision centrality. We compare these products with results from lattice QCD and various models without a critical point and study the root s(NN) dependence of kappa sigma(2). From the measurements at the three beam energies, we find no evidence for a critical point in the QCD phase diagram for mu(B) below 200 MeV.

Observation of an Antimatter Hypernucleus

Abstract: Nuclear collisions recreate conditions in the universe microseconds after the Big Bang. Only a very small fraction of the emitted fragments are light nuclei, but these states are of fundamental interest. We report the observation of antihypertritons-comprising an antiproton, an antineutron, and an antilambda hyperon-produced by colliding gold nuclei at high energy. Our analysis yields 70 +/- 17 antihypertritons (3/Lambda(H) over bar) and 157 +/- 30 hypertritons ((3)(Lambda)H). The measured yields of (3)(Lambda)H (3/Lambda(H) over bar) and (3)He ((3)(He) over bar) are similar, suggesting an equilibrium in coordinate and momentum space populations of up, down, and strange quarks and antiquarks, unlike the pattern observed at lower collision energies. The production and properties of antinuclei, and of nuclei containing strange quarks, have implications spanning nuclear and particle physics, astrophysics, and cosmology.

Identified particle production, azimuthal anisotropy, and interferometry measurements in Au plus Au collisions at root s(NN)=9.2 GeV

Abstract: We present the first measurements of identified hadron production, azimuthal anisotropy, and pion interferometry from Au + Au collisions below the nominal injection energy at the BNL Relativistic Heavy-Ion Collider (RHIC) facility. The data were collected using the large acceptance solenoidal tracker at RHIC (STAR) detector at root s(NN) = 9.2 GeV from a test run of the collider in the year 2008. Midrapidity results on multiplicity density dN/dy in rapidity y, average transverse momentum , particle ratios, elliptic flow, and Hanbury-Brown-Twiss (HBT) radii are consistent with the corresponding results at similar root s(NN) from fixed-target experiments. Directed flow measurements are presented for both midrapidity and forward-rapidity regions. Furthermore the collision centrality dependence of identified particle dN/dy, , and particle ratios are discussed. These results also demonstrate that the capabilities of the STAR detector, although optimized for root s(NN) = 200 GeV, are suitable for the proposed QCD critical-point search and exploration of the QCD phase diagram at RHIC.

An Experimental Exploration of the QCD Phase Diagram: The Search for the Critical Point and the Onset of De-confinement

Abstract: The QCD phase diagram lies at the heart of what the RHIC Physics Program is all about While RHIC has been operating very successfully at or close to its maximum energy for almost a decade, it has become clear that this collider can also be operated at lower energies down to 5 GeV without extensive upgrades An exploration of the full region of beam energies available at the RHIC facility is imperative The STAR detector, due to its large uniform acceptance and excellent particle identification capabilities, is uniquely positioned to carry out this program in depth and detail The first exploratory beam energy scan (BES) run at RHIC took place in 2010 (Run 10), since several STAR upgrades, most importantly a full barrel Time of Flight detector, are now completed which add new capabilities important for the interesting physics at BES energies In this document we discuss current proposed measurements, with estimations of the accuracy of the measurements given an assumed event count at each beam energy

Three-Particle Coincidence of the Long Range Pseudorapidity Correlation in High Energy Nucleus-Nucleus Collisions

Abstract: We report the first three-particle coincidence measurement in pseudorapidity (Δη) between a high transverse momentum (p⊥) trigger particle and two lower p⊥ associated particles within azimuth |Δϕ|<0.7 in √sNN=200 GeV d+Au and Au+Au collisions. Charge ordering properties are exploited to separate the jetlike component and the ridge (long range Δη correlation). The results indicate that the correlation of ridge particles are uniform not only with respect to the trigger particle but also between themselves event by event in our measured Δη. In addition, the production of the ridge appears to be uncorrelated to the presence of the narrow jetlike component.

Measurement of the bottom quark contribution to nonphotonic electron production in p+p collisions at √s=200GeV

Abstract: The contribution of B meson decays to nonphotonic electrons, which are mainly produced by the semileptonic decays of heavy-flavor mesons, in p + p collisions at root s = 200 GeV has been measured using azimuthal correlations between nonphotonic electrons and hadrons. The extracted B decay contribution is approximately 50% at a transverse momentum of p(T) >= 5 GeV/c. These measurements constrain the nuclear modification factor for electrons from B and D meson decays. The result indicates that B meson production in heavy ion collisions is also suppressed at high p(T).

Azimuthal di-hadron correlations in d + Au and Au + Au collisions at √sNN = 200 GeV measured at the STAR detector

Abstract: Yields, correlation shapes, and mean transverse momenta p(T) of charged particles associated with intermediate-to high-p(T) trigger particles (2.5 < p(T) < 10 GeV/c) in d + Au and Au + Au collisions at root s(NN) = 200 GeV are presented. For associated particles at higher p(T) greater than or similar to 2.5 GeV/c, narrow correlation peaks are seen in d + Au and Au + Au, indicating that the main production mechanism is jet fragmentation. At lower associated particle pT < 2 GeV/c, a large enhancement of the near- (Delta phi similar to 0) and away-side (Delta phi similar to pi) associated yields is found, together with a strong broadening of the away-side azimuthal distributions in Au + Au collisions compared to d + Au measurements, suggesting that other particle production mechanisms play a role. This is further supported by the observed significant softening of the away-side associated particle yield distribution at Delta phi similar to pi in central Au + Au collisions.

Measurement of the Bottom Quark Contribution to Nonphotonic Electron Production in p+p Collisions at √s=200 GeV

Abstract: The contribution of B meson decays to nonphotonic electrons, which are mainly produced by the semileptonic decays of heavy-flavor mesons, in p + p collisions at √s=200 GeV has been measured using azimuthal correlations between nonphotonic electrons and hadrons. The extracted B decay contribution is approximately 50% at a transverse momentum of pT≥5 GeV/c. These measurements constrain the nuclear modification factor for electrons from B and D meson decays. The result indicates that B meson production in heavy ion collisions is also suppressed at high pT.

Parton energy loss in heavy-ion collisions via direct-photon and charged-particle azimuthal correlations

Abstract: Charged-particle spectra associated with direct photon (gamma(dir)) and pi(0) are measured in p + p and Au + Au collisions at center-of-mass energy root(S)(NN) = 200 GeV with the STAR detector at the Relativistic Heavy Ion Collider. A shower-shape analysis is used to partially discriminate between gamma(dir) and pi(0). Assuming no associated charged particles in the gamma(dir) direction ( near side) and small contribution from fragmentation photons (gamma(frag)), the associated charged-particle yields opposite to gamma(dir) (away side) are extracted. In central Au + Au collisions, the charged-particle yields at midrapidity (vertical bar eta vertical bar < 1) and high transverse momentum (3 < (assoc)(PT) < 16 GeV/c) associated with gamma(dir) and pi(0) (vertical bar eta vertical bar < 0.9, 8 < (trig)(PT) < 16 GeV/c) are suppressed by a factor of 3-5 compared with p + p collisions. The observed suppression of the associated charged particles is similar for gamma(dir) and pi(0) and independent of the gamma(dir) energy within uncertainties. These measurements indicate that, in the kinematic range covered and within our current experimental uncertainties, the parton energy loss shows no sensitivity to the parton initial energy, path length, or color charge.

Inclusive π0, η, and direct photon production at high transverse momentum in p + p and d + Au collisions at √sNN = 200 GeV

Abstract: We report a measurement of high-p(T) inclusive pi(0), eta, and direct photon production in p + p and d + Au collisions at root s(NN) = 200 GeV at midrapidity (0 gamma gamma were detected in the barrel electromagnetic calorimeter of the STAR experiment at the Relativistic Heavy Ion Collider. The eta -> gamma gamma decay was also observed and constituted the first eta measurement by STAR. The first direct photon cross-section measurement by STAR is also presented; the signal was extracted statistically by subtracting the pi(0), eta, and omega(782) decay background from the inclusive photon distribution observed in the calorimeter. The analysis is described in detail, and the results are found to be in good agreement with earlier measurements and with next-to-leading-order perturbative QCD calculations.

Charged and strange hadron elliptic flow in Cu + Cu collisions at √sNN = 62.4 and 200 GeV

Abstract: We present the results of an elliptic flow, v(2), analysis of Cu + Cu collisions recorded with the solenoidal tracker detector (STAR) at the BNL Relativistic Heavy Ion Collider at root s(NN) = 62.4 and 200 GeV. Elliptic flow as a function of transverse momentum, v(2)(p(T)), is reported for different collision centralities for charged hadrons h(+/-) and strangeness-ontaining hadrons K(S)(0), Lambda, Xi, and phi in the midrapidity region vertical bar eta vertical bar < 1.0. Significant reduction in systematic uncertainty of the measurement due to nonflow effects has been achieved by correlating particles at midrapidity, vertical bar eta vertical bar < 1.0, with those at forward rapidity, 2.5 < vertical bar eta vertical bar < 4.0. We also present azimuthal correlations in p + p collisions at root s = 200 GeV to help in estimating nonflow effects. To study the system-size dependence of elliptic flow, we present a detailed comparison with previously published results from Au + Au collisions at root s(NN) = 200 GeV. We observe that v(2)(p(T)) of strange hadrons has similar scaling properties as were first observed in Au + Au collisions, that is, (i) at low transverse momenta, p(T) < 2 GeV/c, v(2) scales with transverse kinetic energy, m(T) - m, and (ii) at intermediate p(T), 2 < p(T) < 4 GeV/c, it scales with the number of constituent quarks, n(q.) We have found that ideal hydrodynamic calculations fail to reproduce the centrality dependence of v(2)(p(T)) for K(S)(0) and Lambda. Eccentricity scaled v(2) values, v(2)/epsilon, are larger in more central collisions, suggesting stronger collective flow develops in more central collisions. The comparison with Au + Au collisions, which go further in density, shows that v(2)/epsilon depends on the system size, that is, the number of participants N(part). This indicates that the ideal hydrodynamic limit is not reached in Cu + Cu collisions, presumably because the assumption of thermalization is not attained.

Balance functions from Au+Au, d+Au, and p+p collisions at √sNN=200 GeV

Abstract: Balance functions have been measured for charged-particle pairs, identified charged-pion pairs, and identified charged-kaon pairs in Au + Au, d + Au, and p + p collisions at root s(NN) = 200 GeV at the Relativistic Heavy Ion Collider using the STAR detector. These balance functions are presented in terms of relative pseudorapidity, Delta eta, relative rapidity, Delta y, relative azimuthal angle, Delta phi, and invariant relative momentum, q(inv). For charged-particle pairs, the width of the balance function in terms of Delta eta scales smoothly with the number of participating nucleons, while HIJING and UrQMD model calculations show no dependence on centrality or system size. For charged-particle and charged-pion pairs, the balance functions widths in terms of Delta eta and Delta y are narrower in central Au + Au collisions than in peripheral collisions. The width for central collisions is consistent with thermal blast-wave models where the balancing charges are highly correlated in coordinate space at breakup. This strong correlation might be explained by either delayed hadronization or limited diffusion during the reaction. Furthermore, the narrowing trend is consistent with the lower kinetic temperatures inherent to more central collisions. In contrast, the width of the balance function for charged-kaon pairs in terms of Delta y shows little centrality dependence, which may signal a different production mechanism for kaons. The widths of the balance functions for charged pions and kaons in terms of q(inv) narrow in central collisions compared to peripheral collisions, which may be driven by the change in the kinetic temperature.

Balance functions fromAu+Au,d+Au, andp+pcollisions atsNN=200GeV

Abstract: Balance functions have been measured for charged-particle pairs, identified charged-pion pairs, and identified charged-kaon pairs in $\mathrm{Au}+\mathrm{Au}$, $d+\mathrm{Au}$, and $p+p$ collisions at $\sqrt{{s}_{\mathit{NN}}}=200$ GeV at the Relativistic Heavy Ion Collider using the STAR detector. These balance functions are presented in terms of relative pseudorapidity, $\ensuremath{\Delta}\ensuremath{\eta}$, relative rapidity, $\ensuremath{\Delta}y$, relative azimuthal angle, $\ensuremath{\Delta}\ensuremath{\phi}$, and invariant relative momentum, ${q}_{\mathrm{inv}}$. For charged-particle pairs, the width of the balance function in terms of $\ensuremath{\Delta}\ensuremath{\eta}$ scales smoothly with the number of participating nucleons, while hijing and urqmd model calculations show no dependence on centrality or system size. For charged-particle and charged-pion pairs, the balance functions widths in terms of $\ensuremath{\Delta}\ensuremath{\eta}$ and $\ensuremath{\Delta}y$ are narrower in central $\mathrm{Au}+\mathrm{Au}$ collisions than in peripheral collisions. The width for central collisions is consistent with thermal blast-wave models where the balancing charges are highly correlated in coordinate space at breakup. This strong correlation might be explained by either delayed hadronization or limited diffusion during the reaction. Furthermore, the narrowing trend is consistent with the lower kinetic temperatures inherent to more central collisions. In contrast, the width of the balance function for charged-kaon pairs in terms of $\ensuremath{\Delta}y$ shows little centrality dependence, which may signal a different production mechanism for kaons. The widths of the balance functions for charged pions and kaons in terms of ${q}_{\mathrm{inv}}$ narrow in central collisions compared to peripheral collisions, which may be driven by the change in the kinetic temperature.

Y cross section in p+p collisions at s=200 GeV

Abstract: We report on a measurement of the gamma(1S + 2S + 3S) -> e(+)e(-) cross section at midrapidity in p + p collisions at root s = 200 GeV. We find the cross section to be 114 +/- 38(stat + fit)(-24)(+23)(syst) pb. Perturbative QCD calculations at next-to-leading order in the color evaporation model are in agreement with our measurement, while calculations in the color singlet model underestimate it by 2 sigma. Our result is consistent with the trend seen in world data as a function of the center-of-mass energy of the collision and extends the availability of gamma data to RHIC energies. The dielectron continuum in the invariant-mass range near the gamma is also studied to obtain a combined yield of e(+)e(-) pairs from the sum of the Drell-Yan process and b-(b) over bar production.

Measurements of Dihadron Correlations Relative to the Event Plane in Au+Au Collisions at $\sqrt{s_{_{\rm NN}}}=200$ GeV

Abstract: Dihadron azimuthal correlations containing a high transverse momentum ($p_T$) trigger particle are sensitive to the properties of the nuclear medium created at RHIC through the strong interactions occurring between the traversing parton and the medium, i.e. jet-quenching. Previous measurements revealed a strong modification to dihadron azimuthal correlations in Au+Au collisions with respect to p+p and d+Au collisions. The modification increases with the collision centrality, suggesting a path-length or energy density dependence to the jet-quenching effect. This paper reports STAR measurements of dihadron azimuthal correlations in mid-central (20-60%) Au+Au collisions at $\sqrt{s_{_{\rm NN}}}=200$ GeV as a function of the trigger particle's azimuthal angle relative to the event plane, $\phi_s=|\phi_t-\psi_{\rm EP}|$. The azimuthal correlation is studied as a function of both the trigger and associated particle $p_T$. The subtractions of the combinatorial background and anisotropic flow, assuming Zero Yield At Minimum (ZYAM), are described. The correlation results are first discussed with subtraction of the even harmonic (elliptic and quadrangular) flow backgrounds. The away-side correlation is strongly modified, and the modification varies with $\phi_s$, with a double-peak structure for out-of-plane trigger particles. The near-side ridge (long range pseudo-rapidity $\Delta\eta$ correlation) appears to drop with increasing $\phi_s$ while the jet-like component remains approximately constant. The correlation functions are further studied with subtraction of odd harmonic triangular flow background arising from fluctuations. It is found that the triangular flow, while responsible for the majority of the amplitudes, is not sufficient to explain the $\phi_s$-dependence of the ridge or the away-side double-peak structure. ...

Spectra of identified high-pT π± and p(p̄) in Cu+Cu collisions at √sNN=200 GeV

Abstract: We report new results on identified (anti) proton and charged pion spectra at large transverse momenta (3 < p(T) < 10 GeV/c) from Cu + Cu collisions at root s(NN) = 200 GeV using the STAR detector at the Relativistic Heavy Ion Collider (RHIC) This study explores the system size dependence of two novel features observed at RHIC with heavy ions: the hadron suppression at high-p(T) and the anomalous baryon to meson enhancement at intermediate transverse momenta Both phenomena could be attributed to the creation of a new form of QCD matter The results presented here bridge the system size gap between the available pp and Au + Au data, and allow for a detailed exploration of the onset of the novel features Comparative analysis of all available 200 GeV data indicates that the system size is a major factor determining both the magnitude of the hadron spectra suppression at large transverse momenta and the relative baryon to meson enhancement

Observation of π+π-π+π - photoproduction in ultraperipheral heavy-ion collisions at √sNN=200 GeV at the STAR detector

Abstract: We present a measurement of pi(+)pi(-)pi(+)pi(-) photonuclear production in ultraperipheral Au-Au collisions at root s(NN) = 200 GeV from the STAR experiment. The pi(+)pi(-)pi(+)pi(-) final states are observed at low transverse momentum and are accompanied by mutual nuclear excitation of the beam particles. The strong enhancement of the production cross section at low transverse momentum is consistent with coherent photoproduction. The pi(+)pi(-)pi(+)pi(-) invariant mass spectrum of the coherent events exhibits a broad peak around 1540 +/- 40 MeV/c(2) with a width of 570 +/- 60 MeV/c(2), in agreement with the photoproduction data for the rho(0)(1700). We do not observe a corresponding peak in the pi(+)pi(-) final state and measure an upper limit for the ratio of the branching fractions of the rho(0)(1700) to pi(+)pi(-) and pi(+)pi(-)pi(+)pi(-) of 2.5% at 90% confidence level. The ratio of rho(0)(1700) and rho(0)(770) coherent production cross sections is measured to be 13.4 +/- 0.8(stat.) +/- 4.4(syst.)%.

Spectra of identified high-pTπ±andp(p¯)inCu+Cucollisions atsNN=200GeV

Abstract: We report new results on identified (anti)proton and charged pion spectra at large transverse momenta ($3l{p}_{T}l10$ GeV$/c$) from $\mathrm{Cu}+\mathrm{Cu}$ collisions at $\sqrt{{s}_{\mathit{NN}}}=200$ GeV using the STAR detector at the Relativistic Heavy Ion Collider (RHIC). This study explores the system size dependence of two novel features observed at RHIC with heavy ions: the hadron suppression at high-${p}_{T}$ and the anomalous baryon to meson enhancement at intermediate transverse momenta. Both phenomena could be attributed to the creation of a new form of QCD matter. The results presented here bridge the system size gap between the available $\mathit{pp}$ and $\mathrm{Au}+\mathrm{Au}$ data, and allow for a detailed exploration of the onset of the novel features. Comparative analysis of all available 200 GeV data indicates that the system size is a major factor determining both the magnitude of the hadron spectra suppression at large transverse momenta and the relative baryon to meson enhancement.

Υcross section inp+pcollisions ats=200GeV

Abstract: We report on a measurement of the $\ensuremath{\Upsilon}(1\mathrm{S}+2\mathrm{S}+3\mathrm{S})\ensuremath{\rightarrow}{e}^{+}{e}^{\ensuremath{-}}$ cross section at midrapidity in $p+p$ collisions at $\sqrt{s}=200\text{ }\text{ }\mathrm{GeV}$. We find the cross section to be $114\ifmmode\pm\else\textpm\fi{}38(\mathrm{stat}+\mathrm{\text{fit}}{)}_{\ensuremath{-}24}^{+23}(\mathrm{syst})\text{ }\text{ }\mathrm{pb}$. Perturbative QCD calculations at next-to-leading order in the color evaporation model are in agreement with our measurement, while calculations in the color singlet model underestimate it by $2\ensuremath{\sigma}$. Our result is consistent with the trend seen in world data as a function of the center-of-mass energy of the collision and extends the availability of $\ensuremath{\Upsilon}$ data to RHIC energies. The dielectron continuum in the invariant-mass range near the $\ensuremath{\Upsilon}$ is also studied to obtain a combined yield of ${e}^{+}{e}^{\ensuremath{-}}$ pairs from the sum of the Drell-Yan process and $b\mathrm{\text{\ensuremath{-}}}\overline{b}$ production.

Observation Of π+π-π+π - Photoproduction In Ultraperipheral Heavy-ion Collisions At √snn=200 Gev At The Star Detector

Abstract: We present a measurement of pi{sup +}pi{sup -}pi{sup +}pi{sup -} photonuclear production in ultraperipheral Au-Au collisions at sq root(s{sub N{sub N}})=200 GeV from the STAR experiment. The pi{sup +}pi{sup -}pi{sup +}pi{sup -} final states are observed at low transverse momentum and are accompanied by mutual nuclear excitation of the beam particles. The strong enhancement of the production cross section at low transverse momentum is consistent with coherent photoproduction. The pi{sup +}pi{sup -}pi{sup +}pi{sup -} invariant mass spectrum of the coherent events exhibits a broad peak around 1540+-40 MeV/c{sup 2} with a width of 570+-60 MeV/c{sup 2}, in agreement with the photoproduction data for the rho{sup 0}(1700). We do not observe a corresponding peak in the pi{sup +}pi{sup -} final state and measure an upper limit for the ratio of the branching fractions of the rho{sup 0}(1700) to pi{sup +}pi{sup -} and pi{sup +}pi{sup -}pi{sup +}pi{sup -} of 2.5% at 90% confidence level. The ratio of rho{sup 0}(1700) and rho{sup 0}(770) coherent production cross sections is measured to be 13.4+-0.8{sub stat.}+-4.4{sub syst.}%.

Three-Particle Coincidence of the Long Range Pseudorapidity Correlation in High Energy Nucleus-Nucleus Collisions

Abstract: We report the first three-particle coincidence measurement in pseudorapidity (Δη) between a high transverse momentum (p⊥) trigger particle and two lower p⊥ associated particles within azimuth |Δϕ|<0.7 in square root of s(NN)=200 GeV d+Au and Au+Au collisions. Charge ordering properties are exploited to separate the jetlike component and the ridge (long range Δη correlation). The results indicate that the correlation of ridge particles are uniform not only with respect to the trigger particle but also between themselves event by event in our measured Δη. In addition, the production of the ridge appears to be uncorrelated to the presence of the narrow jetlike component.

Charged and strange hadron elliptic flow in Cu+Cu collisions at [sqrt]sNN=62.4 and 200 GeV

Abstract: B. I. Abelev,8 M. M. Aggarwal,31 Z. Ahammed,48 A. V. Alakhverdyants,18 I. Alekseev,16 B. D. Anderson,19 D. Arkhipkin,3 G. S. Averichev,18 J. Balewski,23 L. S. Barnby,2 S. Baumgart,53 D. R. Beavis,3 R. Bellwied,51 M. J. Betancourt,23 R. R. Betts,8 A. Bhasin,17 A. K. Bhati,31 H. Bichsel,50 J. Bielcik,10 J. Bielcikova,11 B. Biritz,6 L. C. Bland,3 B. E. Bonner,37 J. Bouchet,19 E. Braidot,28 A. V. Brandin,26 A. Bridgeman,1 E. Bruna,53 S. Bueltmann,30 I. Bunzarov,18 T. P. Burton,3 X. Z. Cai,41 H. Caines,53 M. Calderón de la Barca Sánchez,5 O. Catu,53 D. Cebra,5 R. Cendejas,6 M. C. Cervantes,43 Z. Chajecki,29 P. Chaloupka,11 S. Chattopadhyay,48 H. F. Chen,39 J. H. Chen,41 J. Y. Chen,52 J. Cheng,45 M. Cherney,9 A. Chikanian,53 K. E. Choi,35 W. Christie,3 P. Chung,11 R. F. Clarke,43 M. J. M. Codrington,43 R. Corliss,23 J. G. Cramer,50 H. J. Crawford,4 D. Das,5 S. Dash,13 A. Davila Leyva,44 L. C. De Silva,51 R. R. Debbe,3 T. G. Dedovich,18 M. DePhillips,3 A. A. Derevschikov,33 R. Derradi de Souza,7 L. Didenko,3 P. Djawotho,43 S. M. Dogra,17 X. Dong,22 J. L. Drachenberg,43 J. E. Draper,5 J. C. Dunlop,3 M. R. Dutta Mazumdar,48 L. G. Efimov,18 E. Elhalhuli,2 M. Elnimr,51 J. Engelage,4 G. Eppley,37 B. Erazmus,42 M. Estienne,42 L. Eun,32 O. Evdokimov,8 P. Fachini,3 R. Fatemi,20 J. Fedorisin,18 R. G. Fersch,20 P. Filip,18 E. Finch,53 V. Fine,3 Y. Fisyak,3 C. A. Gagliardi,43 D. R. Gangadharan,6 M. S. Ganti,48 E. J. Garcia-Solis,8 A. Geromitsos,42 F. Geurts,37 V. Ghazikhanian,6 P. Ghosh,48 Y. N. Gorbunov,9 A. Gordon,3 O. Grebenyuk,22 D. Grosnick,47 B. Grube,35 S. M. Guertin,6 A. Gupta,17 N. Gupta,17 W. Guryn,3 B. Haag,5 A. Hamed,43 L.-X. Han,41 J. W. Harris,53 J. P. Hays-Wehle,23 M. Heinz,53 S. Heppelmann,32 A. Hirsch,34 E. Hjort,22 A. M. Hoffman,23 G. W. Hoffmann,44 D. J. Hofman,8 R. S. Hollis,8 H. Z. Huang,6 T. J. Humanic,29 L. Huo,43 G. Igo,6 A. Iordanova,8 P. Jacobs,22 W. W. Jacobs,15 P. Jakl,11 C. Jena,13 F. Jin,41 C. L. Jones,23 P. G. Jones,2 J. Joseph,19 E. G. Judd,4 S. Kabana,42 K. Kajimoto,44 K. Kang,45 J. Kapitan,11 K. Kauder,8 D. Keane,19 A. Kechechyan,18 D. Kettler,50 D. P. Kikola,22 J. Kiryluk,22 A. Kisiel,49 S. R. Klein,22 A. G. Knospe,53 A. Kocoloski,23 D. D. Koetke,47 T. Kollegger,12 J. Konzer,34 M. Kopytine,19 I. Koralt,30 L. Koroleva,16 W. Korsch,20 L. Kotchenda,26 V. Kouchpil,11 P. Kravtsov,26 K. Krueger,1 M. Krus,10 L. Kumar,31 P. Kurnadi,6 M. A. C. Lamont,3 J. M. Landgraf,3 S. LaPointe,51 J. Lauret,3 A. Lebedev,3 R. Lednicky,18 C.-H. Lee,35 J. H. Lee,3 W. Leight,23 M. J. LeVine,3 C. Li,39 L. Li,44 N. Li,52 W. Li,41 X. Li,40 X. Li,34 Y. Li,45 Z. Li,52 G. Lin,53 S. J. Lindenbaum,27,* M. A. Lisa,29 F. Liu,52 H. Liu,5 J. Liu,37 T. Ljubicic,3 W. J. Llope,37 R. S. Longacre,3 W. A. Love,3 Y. Lu,39 G. L. Ma,41 Y. G. Ma,41 D. P. Mahapatra,13 R. Majka,53 O. I. Mall,5 L. K. Mangotra,17 R. Manweiler,47 S. Margetis,19 C. Markert,44 H. Masui,22 H. S. Matis,22 Yu. A. Matulenko,33 D. McDonald,37 T. S. McShane,9 A. Meschanin,33 R. Milner,23 N. G. Minaev,33 S. Mioduszewski,43 A. Mischke,28 M. K. Mitrovski,12 B. Mohanty,48 M. M. Mondal,48 B. Morozov,16 D. A. Morozov,33 M. G. Munhoz,38 B. K. Nandi,14 C. Nattrass,53 T. K. Nayak,48 J. M. Nelson,2 P. K. Netrakanti,34 M. J. Ng,4 L. V. Nogach,33 S. B. Nurushev,33 G. Odyniec,22 A. Ogawa,3 H. Okada,3 V. Okorokov,26 D. Olson,22 M. Pachr,10 B. S. Page,15 S. K. Pal,48 Y. Pandit,19 Y. Panebratsev,18 T. Pawlak,49 T. Peitzmann,28 V. Perevoztchikov,3 C. Perkins,4 W. Peryt,49 S. C. Phatak,13 P. Pile,3 M. Planinic,54 M. A. Ploskon,22 J. Pluta,49 D. Plyku,30 N. Poljak,54 A. M. Poskanzer,22 B. V. K. S. Potukuchi,17 C. B. Powell,22 D. Prindle,50 C. Pruneau,51 N. K. Pruthi,31 P. R. Pujahari,14 J. Putschke,53 R. Raniwala,36 S. Raniwala,36 R. L. Ray,44 R. Redwine,23 R. Reed,5 J. M. Rehberg,12 H. G. Ritter,22 J. B. Roberts,37 O. V. Rogachevskiy,18 J. L. Romero,5 A. Rose,22 C. Roy,42 L. Ruan,3 R. Sahoo,42 S. Sakai,6 I. Sakrejda,22 T. Sakuma,23 S. Salur,5 J. Sandweiss,53 E. Sangaline,5 J. Schambach,44 R. P. Scharenberg,34 N. Schmitz,24 T. R. Schuster,12 J. Seele,23 J. Seger,9 I. Selyuzhenkov,15 P. Seyboth,24 E. Shahaliev,18 M. Shao,39 M. Sharma,51 S. S. Shi,52,† X. H. Shi,41 E. P. Sichtermann,22 F. Simon,24 R. N. Singaraju,48 M. J. Skoby,34 N. Smirnov,53 P. Sorensen,3 J. Sowinski,15 H. M. Spinka,1 B. Srivastava,34 T. D. S. Stanislaus,47 D. Staszak,6 J. R. Stevens,15 R. Stock,12 M. Strikhanov,26 B. Stringfellow,34 A. A. P. Suaide,38 M. C. Suarez,8 N. L. Subba,19 M. Sumbera,11 X. M. Sun,22 Y. Sun,39 Z. Sun,21 B. Surrow,23 D. N. Svirida,16 T. J. M. Symons,22 A. Szanto de Toledo,38 J. Takahashi,7 A. H. Tang,3 Z. Tang,39 L. H. Tarini,51 T. Tarnowsky,25 D. Thein,44 J. H. Thomas,22 J. Tian,41 A. R. Timmins,51 S. Timoshenko,26 D. Tlusty,11 M. Tokarev,18 V. N. Tram,22 S. Trentalange,6 R. E. Tribble,43 O. D. Tsai,6 J. Ulery,34 T. Ullrich,3 D. G. Underwood,1 G. Van Buren,3 M. van Leeuwen,28 G. van Nieuwenhuizen,23 J. A. Vanfossen Jr.,19 R. Varma,14 G. M. S. Vasconcelos,7 A. N. Vasiliev,33 F. Videbaek,3 Y. P. Viyogi,48 S. Vokal,18 S. A. Voloshin,51 M. Wada,44 M. Walker,23 F. Wang,34 G. Wang,6 H. Wang,25 J. S. Wang,21 Q. Wang,34 X. L. Wang,39 Y. Wang,45 G. Webb,20 J. C. Webb,3 G. D. Westfall,25 C. Whitten Jr.,6 H. Wieman,22 E. Wingfield,44 S. W. Wissink,15 R. Witt,46 Y. Wu,52 W. Xie,34 N. Xu,22 Q. H. Xu,40 W. Xu,6 Y. Xu,39 Z. Xu,3 L. Xue,41 Y. Yang,21 P. Yepes,37 K. Yip,3 I.-K. Yoo,35 Q. Yue,45 M. Zawisza,49 H. Zbroszczyk,49 W. Zhan,21 S. Zhang,41 W. M. Zhang,19 X. P. Zhang,22 Y. Zhang,22 Z. P. Zhang,39 J. Zhao,41 C. Zhong,41 J. Zhou,37 W. Zhou,40 X. Zhu,45 Y. H. Zhu,41 R. Zoulkarneev,18 and Y. Zoulkarneeva18