M.P. Decowski

The PHOBOS Perspective on Discoveries at RHIC

This paper describes the conclusions that can be drawn from the data taken thus far with the PHOBOS detector at RHIC. In the most central Au+Au collisions at the highest beam energy, evidence is found for the formation of a very high energy density system whose description in terms of simple hadronic degrees of freedom is inappropriate. Furthermore, the constituents of this novel system are found to undergo a significant level of interaction. The properties of particle production at RHIC energies are shown to follow a number of simple scaling behaviors, some of which continue trends found at lower energies or in simpler systems. As a function of centrality, the total number of charged particles scales with the number of participating nucleons. When comparing Au+Au at different centralities, the dependence of the yield on the number of participants at higher p T (∼4 GeV/c) is very similar to that at low transverse momentum. The measured values of charged particle pseudorapidity density and elliptic flow were found to be independent of energy over a broad range of pseudorapidities when effectively viewed in the rest frame of one of the colliding nuclei, a property we describe as “extended longitudinal scaling”. Finally, the centrality and energy dependences of several observables were found to factorize to a surprising degree.

Measurement of neutrino oscillation with KamLAND: Evidence of spectral distortion

We present results of a study of neutrino oscillation based on a 766 ton-year exposure of KamLAND to reactor anti-neutrinos. We observe 258 \nuebar\ candidate events with energies above 3.4 MeV compared to 365.2 events expected in the absence of neutrino oscillation. Accounting for 17.8 expected background events, the statistical significance for reactor \nuebar disappearance is 99.998%. The observed energy spectrum disagrees with the expected spectral shape in the absence of neutrino oscillation at 99.6% significance and prefers the distortion expected from \nuebar oscillation effects. A two-neutrino oscillation analysis of the KamLAND data gives \DeltaMSq = 7.9

Experimental investigation of geologically produced antineutrinos with KamLAND

^{+0.6}_{-0.5}\times10^{-5}

Limits on spin-dependent WIMP-nucleon cross sections from 225 live days of XENON100 data

eV

System Size, Energy, Pseudorapidity, and Centrality Dependence of Elliptic Flow

^2

Phobos results on charged particle multiplicity and pseudorapidity distributions in Au+Au, Cu+Cu, d+Au, and p+p collisions at ultra-relativistic energies

. A global analysis of data from KamLAND and solar neutrino experiments yields \DeltaMSq = 7.9

Measurement of the double- β decay half-life of 136Xe with the KamLAND-Zen experiment

^{+0.6}_{-0.5}\times10^{-5}

Charged particle pseudorapidity density distributions from Au+Au collisions at

eV

\sqrt{s_{NN}}

^2

= 130-GeV

and \ThetaParam = 0.40