Propagation of Fast Partons in the Nuclear Medium

The color dipole approach has been applied in the target rest frame to address the issues of transverse momentum broadening and energy loss of a fast quark propagating in the nuclear medium. A recent application of the theory to the FermiLab E772/E866 experimental data, determining the rate of energy loss of a quark propagating in the medium to be 2 to 3 GeV/fm, will be reviewed. Calculations for the transverse momentum distribution will be presented, and the results will be compared to the E866 data. The theory will be shown to compare favorably to the data, and these results will be shown to suggest that the momentum broadening of a quark is about twice the generally accepted size.Comment: 6 pages, 4 figures, Invited talk given at 4th International Conference on Perspectives in Hadronic Physic

The Baffin Bay Region During the Last Interglaciation: Evidence from Northwest Greenland

Coastal sections in the Thule area, northwest Greenland, provide a record of last interglacial glacial and océanographie events on the northern perimeter of Baffin Bay. The record is dated by a combination of thermoluminescence and 14C dating; local and regional correlation is provided by amino acid analyses of mollusc shells, and periods of penetration by warm subarctic water have been identified by their foraminifera and mollusc faunas. Subarctic water reached the area on three occasions : during the Holocene, and in the Early and Late Sangamonian. Maximum, although restricted, ice coverage for the last interglacial/glacial cycle was attained during Middle Sangamonian times, and a smaller advance took place in the Late Wisconsinan. In between ice coverage was similar to the present, or smaller. The record provides a link between events in Arctic Canada and northern Greenland, and shows that in this large region there was a causal relationship between océanographie change and glaciation.Certaines coupes le long de la côte de la région de Thulé fournissent des données sur la glaciation et sur l'océanographie de la partie nord de la mer de Baffin au cours du dernier interglaciaire. Les événements ont été datées grâce à la combinaison des âges obtenus par thermoluminescence et par le 14C; les corrélations locales et régionales ont été établies par l'analyse des acides aminés à partir des coquillages de mollusques; les périodes où les eaux chaudes subarctiques ont pénétré dans la région ont été identifiées grâce aux faunes des foraminifères et des mollusques. Les eaux subarctiques ont atteint la région en trois occasions: pendant l'Holocène, puis au début et à la fin du Sangamonien. Le recouvrement glaciaire maximal au cours du cycle interglaciaire-glaciaire, bien que limité, s'est produit au milieu du Sangamonien, et une avancée de moindre importance s'est produite au Wisconsinien supérieur. Entre les deux événements, la couverture glaciaire était semblable à celle d'aujourd'hui ou moindre. Ces données permettent d'établir des liens entre les événements qui se sont produits dans l'Arctique canadien et dans le nord du Groenland, et démontrent qu'il y a des relations de cause à effet entre les changements d'ordre océanographique et la glaciation.Kustenschnitte im Thule-Gebiet, Nordwest-Grônland, geben Zeugnis von den glazialen und ozeanographischen Ereignissen im nôrdlichen Umkreis der Baffin Bay wàhrend der letzten Interglazialzeit. Dièse Ereignisse konnten mit Hilfe der Kombination von Thermoluminiszenz und 14C datiert werden: Mittels Aminosàureanalysen der Schalen von Mollusken konnte eine lokale und régionale Korrelation erreicht werden, und Perioden der Eindringung warmen subarktischen Wassers wurden mittels ihrer Foraminifera und MoIlusken-Fauna identifiziert. Subarktisches Wasser erreichte das Gebiet bei drei GeIegenheiten: wàhrend des Holozàn und im frùhen und spàten Sangamonium. Die maximale wenn auch begrenzte Eisbedeckung im letzten interglazialen/glazialen Zyklus wurde in den Zeiten des mittleren Sangamoniums erreicht, und ein geringerer Vorstoss fand im spàten Wisconsinium statt. Dazwischen war die Eisbedeckung àhnlich wie in der Jetztzeit oder geringer. Dièse Ergebnisse lassen eine Beziehung zwischen Ereignissen im arktischen Kanada und nôrdlichen Grônland erkennen und zeigen, dass es in diesem weiten Gebiet eine Kausalbeziehung zwischen ozeanographischer Verânderung und Vereisung gab

Metric fluctuations and its evolution during inflation

W discuss the evolution of the fluctuations in a symmetric $\phi_c$-exponential potential which provides a power-law expansion during inflation using both, the gauge invariant field $\Phi$ and the Sasaki-Mukhanov field.Comment: version accepted in EPJ

Precision of single-qubit gates based on Raman transitions

We analyze the achievable precision for single-qubit gates that are based on Raman transitions between two near-degenerate ground states via a virtually excited state. In particular, we study the errors due to non-perfect adiabaticity and due to spontaneous emission from the excited state. For the case of non-adabaticity, we calculate the error as a function of the dimensionless parameter $\chi=\Delta \tau$, where $\Delta$ is the detuning of the Raman beams and $\tau$ is the gate time. For the case of spontaneous emission, we give an analytical argument that the gate errors are approximately equal to $\Lambda \gamma/\Delta$, where $\Lambda$ is the rotation angle of the one-qubit gate and $\gamma$ is the spontaneous decay rate, and we show numerically that this estimate holds to good approximation.Comment: 8 pages, 10 figure

Transient dynamics of linear quantum amplifiers

The transient dynamics of a quantum linear amplifier during the transition from damping to amplification regime is studied. The master equation for the quantized mode of the field is solved, and the solution is used to describe the statistics of the output field. The conditions under which a nonclassical input field may retain nonclassical features at the output of the amplifier are analyzed and compared to the results of earlier theories. As an application we give a dynamical description of the departure of the system from thermal equilibrium.Comment: 10 pages, 6 figures. V2: extended discussion on application

Petition of Daniel G. Skinner

26-1ClaimsR-C of D. Skinner. [377] Alabama militia supplies; Indian war of 1836.1841-1

Study of deuteron-proton charge exchange reaction at small transfer momentum

The charge-exchange reaction pd->npp at 1 GeV projectile proton energy is studied in the multiple-scattering expansion technique. This reaction is considered in a special kinematics, when the transfer momentum from the beam proton to fast neutron is close to zero. The differential cross section and a set of polarization observables are calculated. It was shown that contribution of the final state interaction between two protons is very significant.Comment: 11 pages, 8 figure

SANTRAUKOS

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Probing dense and hot matter with low-mass dileptons and photons

Results on low-mass dileptons, covering the very broad energy range from the BEVALAC up to SPS are reviewed. The emphasis is on the open questions raised by the intriguing results obtained so far and the prospects for addressing them in the near future with the second generation of experiments, in particular HADES, NA60 and PHENIX.Comment: 6 pages, 8 figures, Proceedings of Hard Probes 2004 Conference, Ericeira, November 4-10, 2004. Caption of Figure 2 corrected. To be published in Eur. Phys. J. C. The orginal version is available at www.springerlink.co