Effect of event selection on jetlike correlation measurement in $d$+Au collisions at $\sqrt{s_{\rm{NN}}}=200$ GeV

Dihadron correlations are analyzed in $\sqrt{s_{_{\rm NN}}} = 200$ GeV $d$+Aucollisions classified by forward charged particle multiplicity and zero-degreeneutral energy in the Au-beam direction. It is found that the jetlikecorrelated yield increases with the event multiplicity. After taking intoaccount this dependence, the non-jet contribution on the away side is minimal,leaving little room for a back-to-back ridge in these collisions.

Long-range pseudorapidity dihadron correlations in $d$+Au collisions at $\sqrt{s_{\rm NN}}=200$ GeV

Dihadron angular correlations in $d$+Au collisions at $\sqrt{s_{\rm NN}}=200$GeV are reported as a function of the measured zero-degree calorimeter neutralenergy and the forward charged hadron multiplicity in the Au-beam direction. Afinite correlated yield is observed at large relative pseudorapidity($\Delta\eta$) on the near side (i.e. relative azimuth $\Delta\phi\sim0$). Thiscorrelated yield as a function of $\Delta\eta$ appears to scale with thedominant, primarily jet-related, away-side ($\Delta\phi\sim\pi$) yield. TheFourier coefficients of the $\Delta\phi$ correlation, $V_{n}=\langle\cosn\Delta\phi\rangle$, have a strong $\Delta\eta$ dependence. In addition, it isfound that $V_{1}$ is approximately inversely proportional to the mid-rapidityevent multiplicity, while $V_{2}$ is independent of it with similar magnitudein the forward ($d$-going) and backward (Au-going) directions.

Energy dependence of acceptance-corrected dielectron excess mass spectrum at mid-rapidity in Au+Au collisions at $\sqrt{s_{NN}} = 19.6$ and 200 GeV

The acceptance-corrected dielectron excess mass spectra, where the knownhadronic sources have been subtracted from the inclusive dielectron massspectra, are reported for the first time at mid-rapidity $|y_{ee}|<1$ inminimum-bias Au+Au collisions at $\sqrt{s_{NN}}$ = 19.6 and 200 GeV. The excessmass spectra are consistently described by a model calculation with a broadened$\rho$ spectral function for $M_{ee}<1.1$ GeV/$c^{2}$. The integrateddielectron excess yield at $\sqrt{s_{NN}}$ = 19.6 GeV for $0.4<M_{ee}<0.75$GeV/$c^2$, normalized to the charged particle multiplicity at mid-rapidity, hasa value similar to that in In+In collisions at $\sqrt{s_{NN}}$ = 17.3 GeV. For$\sqrt{s_{NN}}$ = 200 GeV, the normalized excess yield in central collisions ishigher than that at $\sqrt{s_{NN}}$ = 17.3 GeV and increases from peripheral tocentral collisions. These measurements indicate that the lifetime of the hot,dense medium created in central Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeVis longer than those in peripheral collisions and at lower energies.

Study of the quasi-free $np \to np \pi^+\pi^-$ reaction with a deuterium beam at 1.25 GeV/nucleon

The tagged quasi-free $np \to np\pi^+\pi^-$ reaction has been studiedexperimentally with the High Acceptance Di-Electron Spectrometer (HADES) at GSIat a deuteron incident beam energy of 1.25 GeV/nucleon ($\sqrt s \sim$ 2.42GeV/c for the quasi-free collision). For the first time, differentialdistributions for $\pi^{+}\pi^{-}$ production in $np$ collisions have beencollected in the region corresponding to the large transverse momenta of thesecondary particles. The invariant mass and angular distributions for the$np\rightarrow np\pi^{+}\pi^{-}$ reaction are compared with different models.This comparison confirms the dominance of the $t$-channel with $\Delta\Delta$contribution. It also validates the changes previously introduced in theValencia model to describe two-pion production data in other isospin channels,although some deviations are observed, especially for the $\pi^{+}\pi^{-}$invariant mass spectrum. The extracted total cross section is also in muchbetter agreement with this model. Our new measurement puts useful constraintsfor the existence of the conjectured dibaryon resonance at mass M$\sim$ 2.38GeV and with width $\Gamma\sim$ 70 MeV.

Cross Sections and Transverse Single-Spin Asymmetries in Forward Jet Production from Proton Collisions at $\sqrt{s}=500$ GeV

Measurements of the production of forward jets from transversely polarizedproton collisions at $\sqrt{s}=500$ GeV conducted at the Relativistic Heavy IonCollider (RHIC) are reported. Our measured jet cross section is consistent withhard scattering expectations. Our measured analyzing power for forward jetproduction is small and positive, and provides constraints on the Siversfunctions that are related to partonic orbital angular momentum throughtheoretical models.

Di-Hadron Correlations with Identified Leading Hadrons in 200 GeV Au+Au and d+Au Collisions at STAR

The STAR collaboration presents for the first time two-dimensional di-hadroncorrelations with identified leading hadrons in 200 GeV central Au+Au andminimum-bias d+Au collisions to explore hadronization mechanisms in the quarkgluon plasma. The enhancement of the jet-like yield for leading pions in Au+Audata with respect to the d+Au reference and the absence of such an enhancementfor leading non-pions (protons and kaons) are discussed within the context of aquark recombination scenario. The correlated yield at large angles,specifically in the \emph{ridge region}, is found to be significantly higherfor leading non-pions than pions. The consistencies of the constituent quarkscaling, azimuthal harmonic model and a mini-jet modification model descriptionof the data are tested, providing further constraints on hadronization.

The transverse momentum dependence of charged kaon Bose-Einstein correlations in the SELEX experiment

We report on the measurement of the one-dimensional charged kaon correlationfunctions using 600~GeV/{\it c} $\Sigma^-$, $\pi^-$ and 540~GeV/{\it c} $p$beams from the SELEX~(E781) experiment at the Fermilab Tevatron.$K^{\pm}K^{\pm}$ correlation functions are studied for three transverse pairmomentum, $k_T$, ranges and parameterized by a Gaussian form. The emissionsource radii, $R$, and the correlation strength, $\lambda$, are extracted. Theanalysis shows a decrease of the source radii with increasing kaon transversepair momentum for all beam types.

Structure and optical properties of thin poly(p-xylylene) – Silver nanocomposite films prepared by low-temperature vapor deposition polymerization

Bragg Grating Sensors in Laser-written Single Mode Polymer Waveguides

We present a technology for integrating Bragg gratings with single mode polymer waveguides fabricated in the EpoCore/EpoClad material system. The gratings were inscribed in a photosensitive polymethyl methacrylate (PMMA) coatingusing a phase mask and then transferred in the lower cladding layer using reactive ion etching maintaining compatibility withstandard waveguide fabrication technologies. Subsequently, the waveguide core was patterned on top using laser direct-write lithography of a spin-coated polymer layer. When exciting the waveguides with a broadband spectrum around 1550nm, 2 reflection peaks around 1580nm were found corresponding to the fundamental TE and TM mode in the polymer waveguide. Eventually, this technology will be used for structural health monitoring in concrete constructions or composite materials

Additive Technologies for Ceramic MEMS Sensors

The application of MEMS technology for the fabrication of MOX sensors with low power consumption becomes now a very important trend in gas sensor design. However, traditional silicon technology has some evident disadvantages, when applied in high-temperature devices produced in limited batch. We present our attempt to combine the advantages of ceramic MEMS technology (high working (600°C) and technological treatment (1000°C) temperature, chemical stability at high temperature) with the advantages of additive technologies for the fabrication of functional elements of gas sensor (heaters, sensing, and catalytic layers). We developed conductive silver, gold and platinum nanoparticle (10–30nm) inks usable in ink and aerosol jet printers and demonstrated the possibility to fabricate narrow conductive lines of microheaters and electrodes of sensor (line width ∼ 35μm). The combination of jet printing onto thin ceramic substrate with laser cutting enables the fabrication of advanced cantilever type sensors operating in pulsing heating mode