Halos and related structures

The halo structure originated in nuclear physics but is now encountered more widely. It appears in loosely bound, clustered systems where the spatial extension of the system is significantly larger than that of the binding potentials. A review is given on our current understanding of these structures, with an emphasis on how the structures evolve as more cluster components are added, and on the experimental situation concerning halo states in light nuclei.Comment: 27 pages, 3 figures, Contribution to Nobel Symposium 152 "Physics With Radioactive Beams

Two-kaon correlations in central Pb + Pb collisions at 158 A GeV/c

Two-particle interferometry of positive kaons is studied in Pb + Pb collisions at mean transverse momenta $\approx 0.25$ and 0.91 GeV/c. A three-dimensional analysis was applied to the lower $p_T$ data, while a two-dimensional analysis was used for the higher $p_T$ data. We find that the source size parameters are consistent with the $m_T$ scaling curve observed in pion correlation measurements in the same collisions, and that the duration time of kaon emission is consistent with zero within the experimental sensitivity.Comment: 4 pages incl. 1 table and 3 fig's; RevTeX; accepted for publication in PR

Fusion versus Breakup: Observation of Large Fusion Suppression for ^9Be + ^{208}Pb

Complete fusion excitation functions for $^{9}$Be + $^{208}$Pb have been measured to high precision at near barrier energies. The experimental fusion barrier distribution extracted from these data allows reliable prediction of the expected complete fusion cross-sections. However, the measured cross-sections are only 68% of those predicted. The large cross-sections observed for incomplete fusion products support the interpretation that this suppression of fusion is caused by $^{9}$Be breaking up into charged fragments before reaching the fusion barrier. Implications for the fusion of radioactive nuclei are discussed.Comment: RevTex, 11 pages, 2 postscript figures, to appear in PR

Q^2 Evolution of the Neutron Spin Structure Moments using a He-3 Target

We have measured the spin structure functions $g_1$ and $g_2$ of $^3$He in a double-spin experiment by inclusively scattering polarized electrons at energies ranging from 0.862 to 5.07 GeV off a polarized $^3$He target at a 15.5$^{\circ}$ scattering angle. Excitation energies covered the resonance and the onset of the deep inelastic regions. We have determined for the first time the $Q^2$ evolution of $\Gamma_1(Q^2)=\int_0^{1} g_1(x,Q^2) dx$, $\Gamma_2(Q^2)=\int_0^1 g_2(x,Q^2) dx$ and $d_2 (Q^2) = \int_0^1 x^2[ 2g_1(x,Q^2) + 3g_2(x,Q^2)] dx$ for the neutron in the range 0.1 GeV$^2$ $\leq Q^2 \leq$ 0.9 GeV$^2$ with good precision. $\Gamma_1(Q^2)$ displays a smooth variation from high to low $Q^2$. The Burkhardt-Cottingham sum rule holds within uncertainties and $d_2$ is non-zero over the measured range.Comment: 5 pages, 2 figures, submitted to Phys. Rev. Lett.. Updated Hermes data in Fig. 2 (top panel) and their corresponding reference. Updated the low x extrapolation error Fig. 2 (middle panel). Corrected references to ChiPT calculation

Flow Measurements via Two-particle Azimuthal Correlations in Au + Au Collisions at sqrt(s_NN) = 130 GeV

Two particle azimuthal correlation functions are presented for charged hadrons produced in Au + Au collisions at RHIC sqrt(s_NN) = 130 GeV. The measurements permit determination of elliptic flow without event-by-event estimation of the reaction plane. The extracted elliptic flow values v_2 show significant sensitivity to both the collision centrality and the transverse momenta of emitted hadrons, suggesting rapid thermalization and relatively strong velocity fields. When scaled by the eccentricity of the collision zone, epsilon, the scaled elliptic flow shows little or no dependence on centrality for charged hadrons with relatively low p_T. A breakdown of this epsilon scaling is observed for charged hadrons with p_T > 1.0 GeV/c for the most central collisions.Comment: 6 pages, RevTeX 3, 4 figures, 307 authors, submitted to Phys. Rev. Lett. on 11 April 2002. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (will be made) publicly available at http://www.phenix.bnl.gov/phenix/WWW/run/phenix/papers.htm

Centrality Dependence of Charged Particle Multiplicity in Au-Au Collisions at sqrt(s_NN)=130 GeV

We present results for the charged-particle multiplicity distribution at mid-rapidity in Au - Au collisions at sqrt(s_NN)=130 GeV measured with the PHENIX detector at RHIC. For the 5% most central collisions we find $dN_{ch}/d\eta_{|\eta=0} = 622 \pm 1 (stat) \pm 41 (syst)$. The results, analyzed as a function of centrality, show a steady rise of the particle density per participating nucleon with centrality.Comment: 307 authors, 43 institutions, 6 pages, 4 figures, 1 table Minor changes to figure labels and text to meet PRL requirements. One author added: M. Hibino of Waseda Universit

Formation of dense partonic matter in relativistic nucleus-nucleus collisions at RHIC: Experimental evaluation by the PHENIX collaboration

Extensive experimental data from high-energy nucleus-nucleus collisions were recorded using the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC). The comprehensive set of measurements from the first three years of RHIC operation includes charged particle multiplicities, transverse energy, yield ratios and spectra of identified hadrons in a wide range of transverse momenta (p_T), elliptic flow, two-particle correlations, non-statistical fluctuations, and suppression of particle production at high p_T. The results are examined with an emphasis on implications for the formation of a new state of dense matter. We find that the state of matter created at RHIC cannot be described in terms of ordinary color neutral hadrons.Comment: 510 authors, 127 pages text, 56 figures, 1 tables, LaTeX. Submitted to Nuclear Physics A as a regular article; v3 has minor changes in response to referee comments. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

Measurements of neutrino oscillation in appearance and disappearance channels by the T2K experiment with 6.6 x 10(20) protons on target

111 pages, 45 figures, submitted to Physical Review D. Minor revisions to text following referee comments111 pages, 45 figures, submitted to Physical Review D. Minor revisions to text following referee comments111 pages, 45 figures, submitted to Physical Review D. Minor revisions to text following referee commentsWe thank the J-PARC staff for superb accelerator performance and the CERN NA61/SHINE Collaboration for providing valuable particle production data. We acknowledge the support of MEXT, Japan; NSERC, NRC, and CFI, Canada; CEA and CNRS/IN2P3, France; DFG, Germany; INFN, Italy; National Science Centre (NCN), Poland; RSF, RFBR and MES, Russia; MINECO and ERDF funds, Spain; SNSF and SER, Switzerland; STFC, UK; and the U. S. Deparment of Energy, USA. We also thank CERN for the UA1/NOMAD magnet, DESY for the HERA-B magnet mover system, NII for SINET4, the WestGrid and SciNet consortia in Compute Canada, GridPP, UK, and the Emerald High Performance Computing facility in the Centre for Innovation, UK. In addition, participation of individual researchers and institutions has been further supported by funds from ERC (FP7), EU; JSPS, Japan; Royal Society, UK; and DOE Early Career program, USA

Measurement of the electron neutrino charged-current interaction rate on water with the T2K ND280 pi(0) detector

10 pages, 6 figures, Submitted to PRDhttp://journals.aps.org/prd/abstract/10.1103/PhysRevD.91.112010© 2015 American Physical Society11 pages, 6 figures, as accepted to PRD11 pages, 6 figures, as accepted to PRD11 pages, 6 figures, as accepted to PR

Search for short baseline nu(e) disappearance with the T2K near detector

8 pages, 6 figures, submitted to PRD rapid communication8 pages, 6 figures, submitted to PRD rapid communicationWe thank the J-PARC staff for superb accelerator performance and the CERN NA61 collaboration for providing valuable particle production data. We acknowledge the support of MEXT, Japan; NSERC, NRC and CFI, Canada; Commissariat `a l’Energie Atomique and Centre National de la Recherche Scientifique–Institut National de Physique Nucle´aire et de Physique des Particules, France; DFG, Germany; INFN, Italy; National Science Centre (NCN), Poland; Russian Science Foundation, RFBR and Ministry of Education and Science, Russia; MINECO and European Regional Development Fund, Spain; Swiss National Science Foundation and State Secretariat for Education, Research and Innovation, Switzerland; STFC, UK; and DOE, USA. We also thank CERN for the UA1/NOMAD magnet, DESY for the HERA-B magnet mover system, NII for SINET4, the WestGrid and SciNet consortia in Compute Canada, GridPP, UK. In addition participation of individual researchers and institutions has been further supported by funds from ERC (FP7), EU; JSPS, Japan; Royal Society, UK; DOE Early Career program, USA