Ultrahigh energy neutrinos, small x and unitarity

The ultrahigh energy cross section for neutrino interactions with nucleons is reviewed, and unitarity constraints are discussed. We argue that existing QCD extrapolations are self-consistent, and do not imply a breakdown of the perturbative expansion in the weak coupling.Comment: 5 pages, 2 figures, RevTeX4, contribution to Snowmass 200

Q_T Resummation in Transversely Polarized Drell-Yan Process

We calculate QCD corrections to transversely polarized Drell-Yan process at a measured $Q_T$ of the produced lepton pair in the dimensional regularization scheme. The $Q_T$ distribution is discussed resumming soft gluon effects relevant for small $Q_T$.Comment: 4 pages, 1 figure, contribution to proceedings of International Conference on QCD and Hadronic Physics, Beijing, June 16-20, 200

Resummed Cross Section for Jet Production at Hadron Colliders

We study the resummation of large logarithmic perturbative corrections to the single-inclusive jet cross section at hadron colliders. The corrections we address arise near the threshold for the partonic reaction, when the incoming partons have just enough energy to produce the high-transverse-momentum final state. The structure of the resulting logarithmic corrections is known to depend crucially on the treatment of the invariant mass of the produced jet at threshold. We allow the jet to have a non-vanishing mass at threshold, which most closely corresponds to the situation in experiment. Matching our results to available semi-analytical next-to-leading-order calculations, we derive resummed results valid to next-to-leading logarithmic accuracy. We present numerical results for the resummation effects at Tevatron and RHIC energies.Comment: 10 figures include

QCD Corrections to Dilepton Production near Partonic Threshold in proton-antiproton Scattering

We present a recent study of the QCD corrections to dilepton production near partonic threshold in transversely polarized \bar{p}p scattering. We analyze the role of the higher-order perturbative QCD corrections in terms of the available fixed-order contributions as well as of all-order soft-gluon resummations for the kinematical regime of proposed experiments at GSI-FAIR. We find that perturbative corrections are large for both unpolarized and polarized cross sections, but that the spin asymmetries are stable. The role of the far infrared region of the momentum integral in the resummed exponent and the effect of the NNLL resummation are briefly discussed.Comment: 6 pages, 8 figures, to appear in the proceedings of the "7th International Symposium on Radiative Corrections (RADCOR05)", Shonan Village, Japan, 200

Longitudinal spin transfer of Lambda and anti-Lambda in polarized pp collisions at \sqrt s=200 GeV at STAR

We report our measurement on longitudinal spin transfer, D_LL, from high energy polarized protons to $\Lambda$ and $\bar{\Lambda}$ hyperons in proton-proton collisions at $\sqrt{s} = 200 GeV$ with the STAR detector at RHIC. The current measurements cover $\Lambda$, $\bar\Lambda$ pseudorapidity $|\eta| < 1.2$ and transverse momenta $p_T$ up to $4GeV/c$ using the data taken in 2005. The longitudinal spin transfer is found to be D_LL= -0.03\pm 0.13 (stat) \pm 0.04(syst)$for inclusive$\Lambda$and$D_{LL} = -0.12 \pm 0.08(stat) \pm 0.03(syst)$for inclusive$\bar{\Lambda}$hyperons with$ = 0.5$and$ = 3.7 GeV/c$. The prospects with 2009 data and the future measurements are also given.Comment: 6 pages, 3 figures, presentation at the SPIN2010 International Symposium, Juelich (Germany), Sep. 27-Oct. 2, 201

Dilepton production near partonic threshold in transversely polarized proton-antiproton collisions

It has recently been suggested that collisions of transversely polarized protons and antiprotons at the GSI could be used to determine the nucleon's transversity densities from measurements of the double-spin asymmetry for the Drell-Yan process. We analyze the role of higher-order perturbative QCD corrections in this kinematic regime, in terms of the available fixed-order contributions as well as of all-order soft-gluon resummations. We find that the combined perturbative corrections to the individual unpolarized and transversely polarized cross sections are large. We trace these large enhancements to soft gluon emission near partonic threshold, and we suggest that with a physically-motivated cut-off enhancements beyond lowest order are moderated relative to resummed perturbation theory, but still significant. The unpolarized dilepton cross section for the GSI kinematics may therefore provide information on the relation of perturbative and nonperturbative dynamics in hadronic scattering. The spin asymmetry turns out to be rather robust, relatively insensitive to higher orders, resummation, and the cut-offs.Comment: 23 pages, 19 figures as eps. Some discussion and references added. Final version to appear in Phys. Rev.

Skummingsproblemer i råtnetanker ved Rambekk renseanlegg, Gjøvik kommune

Årsliste 2002Gjøvik kommune har skummingsproblemer i råtnetankene ved Rambekk RA. Problemet har vært særlig alvorlig sen-vinter og vår 2002. Skummingen i råtnetankene mener vi skyldes et kjemisk stoff i slammet, og primært ikke tilstedeværelsen av spesielle organismer. Problemene kan forsterkes av rask og kraftig oppvarming av slammet i en varmeveksler på anlegget. Høy fettilførsel er en mulig hovedårsak til problemene. Selv om mye fett tilføres via Lillehammer-slammet (ca 250 kg/uke), er det sannsynligvis en stor uidentifisert fettkilde internt i Gjøvik kommune. en stor uidentifisert fettkilde internt i Gjøvik kommune. Det er flere slamtyper som har evne til å produsere mye skum, i særlig grad slam fra Skreia RA, Lena RA og Lillehammer RA. Skummet elimineres effektivt med ca 15 ppm Nalco skumdemper. Vi anbefaler en mer inngående kildekartlegging for fett. Videre bør man vurdere å montere en skumfelle på gassavdraget, og jobbe med tiltak for å øke spesifikk slamtilførsel. Varmeveksleren for slamoppvarming bør gjennomgås. Det er mulig et skum-radarsystem kan være nyttig for å få stabil drift, men dette eliminerer ikke årsaken til problemene. Øvrige årsaker til drifts-problemene kan være lav belastning på råtnetanker, høyt fettsyrenivå og høy alkalitet.Gjøvik kommun