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INTERNATIONAL JOURNAL OF HIGH-ENERGY PHYSICS CERN COURIER VOLUME 43 NUMBER 7 SEPTEMBER 2003 Net closes in on quark-gluon plasma NEW PARTICLES POLARIZED DEUTERONS ROLF HAGEDORN Four quarks and an antiquark p5 New record for solid targets p7 The tale of a temperature p30 Solid State Microwave Amplifiers • Pulsed or CW to 12GHz Solid State Microwave Amplifiers Our Customers include: • Complete load mismatch tolerance CER; • Unbeatable power densities (eg lliW Broadband CW in 12u rack, 4kW/1kW at 1.3GHz/2.998GHz pulsed in 4u rack) • Pulse Width to 200 microsecs • Full Built-in Test • Water Cooled Option fk«i 6: a . c DESIGNERS AND MANUFACTURERS OF HIGH POWER MICROWAVE AMPLIFIERS AND SYSTEMS Milmega Ltd, Ryde Business Park, Nicholson Road, Ryde, Isle of Wight P033 1BQ UK Tel:+44(0) 1983 618005 Fax:+44(0) 1983 811521 [email protected] www.milmega.co.uk ...on your wavelength CONTENTS Covering current developments in high- energy physics and related fields worldwide CERN Courier (ISSN 0304-288X) is distributed to member state governments, institutes and laboratories affiliated with CERN, and to their personnel. It is published monthly, except for January and August, in English and French editions. The views expressed are CERN not necessarily those of the CERN management. Editor Christine Sutton CERN, 1211 Geneva 23, Switzerland E-mail: [email protected] Fax: +41 (22) 782 1906 Web: cerncourier.com COURIER Advisory Board R Landua (Chairman), P Sphicas, K Potter, Volume 43 Number 7 September 2003 E Lillest0l, C Detraz, H Hoffmann, R Bailey Laboratory correspondents: Argonne National Laboratory (US): D Ayres Brookhaven, National Laboratory (US): PYamin Cornell University (US): D G Cassel DESY Laboratory (Germany): Ilka Flegel, P Waloschek Fermi National Accelerator Laboratory (US): Judy Jackson GSI Darmstadt (Germany): G Siegert INFN (Italy): Barbara Gallavotti IHEP, Beijing (China): Tongzhou Xu Jefferson Laboratory (US): Mela nie 0'Byrne JINR Dubna (Russia): B Starchenko KEK National Laboratory (Japan): A Maki Lawrence Berkeley Laboratory (US): Christine Celata Los Alamos National Laboratory (US): C Hoffmann Good news for Gran Sasso p6 Heavy ions at ALICE p20 *New head of UK fusion p39 NIKHEF Laboratory (Netherlands): P Mulders Novosibirsk Institute (Russia): S Eidelman Orsay Laboratory (France): Anne-Marie Lutz PSI Laboratory (Switzerland): P-R Kettle News 5 Rutherford Appleton Laboratory (UK): Jacky Hutchinson Four labs find five-quark particle. Gran Sasso puts its troubles in order. Saclay Laboratory (France): Elisabeth Locci JLab's upgraded FEL produces first light Bochum breaks deuteron IHEP, Serpukhov (Russia): Yu Ryabov Stanford Linear Accelerator Center (US): N Calder polarization records. CERN offers grants to young Asian postgraduates. TRIUMF Laboratory (Canada): M K Craddock BES collaboration observes new narrow state. Test stand for RF couplers Produced for CERN by Institute of Physics Publishing Ltd inaugurated at Orsay. Laser spectroscopy tests for inconstant constants. Institute of Physics Publishing Ltd, Dirac House, Temple Back, Bristol BS16BE,UK Tel: +44 (0)117 929 7481 Physicswatch 13 E-mail: [email protected] Web: iop.org Astrowatch 15 Publishing director Richard Roe Publisher Jo Nicholas Art director Andrew Giaquinto Features Senior production editor Ruth Aspinall Technical illustrator Alison Tovey The net closes in on quark-gluon plasma 17 Display advertisement manager Jonathan Baron Two articles describe new results in two different energy regions, from Recruitment advertisement manager Jayne Purdy Display sales Ed Jost NA49 at lower SPS energies and from the higher energies of RHIC, Recruitment sales Reena Gupta while a third looks forward to studies at the Large Hadron Collider. Advertisement production Jackie Cooke, Joanne Scriven Product manager Claire Webber On the trail of dark energy 23 Advertising Jonathan Baron, Jayne Purdy, Ed Jost or Reena Gupta Tel: +44 (0)117 930 1265 Eric Under describes efforts to understand the mysterious energy that E-mail: [email protected] Fax: +44 (0)117 930 1178 dominates the universe. General distribution Jacques Dallemagne, CERN, 1211 Geneva 23, Switzerland. E-mail: [email protected] mSUGRA celebrates its 20th year 27 In certain countries, to request copies or to make address Paul Frampton and Pran Nath review the SUGRA20 conference. changes, contact: China Chen Huaiwei, Institute of High-Energy Physics, PO Box 918, Beijing, People's Republic of China The tale of the Hagedorn temperature 300 Germany Gabriela Heessel orVeronika Werschner, DESY, Notkestr. 85, 22603 Hamburg 52. E-mail: [email protected] Johann Rafelskiand Torleif Ericson recall Rolf Hagedorn's discovery Italy Loredana Rum or Anna Pennacchietti, INFN, Casella Postale of a "melting point" for hadrons. 56, 00044 Frascati, Roma UK Mark Swaisland, CLRC, Daresbury Laboratory, Keckwick Lane, Daresbury, Warrington WA4 4AD. E-mail: [email protected] Frontier techniques for particle physics and beyond 35 US/Canada Published by Cern Courier, 6N246 Willow Drive, St Charles, IL 60175. Periodical postage paid in St Charles, IL Giorgio Chiarelli reports on the 9th Pisa Meeting on Advanced Detectors. Fax: 630 377 1569. E-mail: [email protected]. Postmaster: send address changes to: Creative Mailing Services, PO Box 1147, St Charles, IL 60174 People 39 Published by European Organization for Nuclear Research, CERN, 1211 Geneva 23, Switzerland. Tel: +41 (22) 767 6111 47 Telefax: +41(22) 767 65 55 Recruitment Printed by Warners (Midlands) pic, Bourne, Lincolnshire, UK Bookshelf 55 © 2003 CERN ISSN 0304-288X Viewpoint 58 Cover: Events like this simulation of a lead-lead collision in the ALICE detector will allow the exploration of the dense quark-gluon plasma at CERN's Large Hadron Collider (pl7). f\ INTRODUCING ORIGIN- 7.5 OriginLab has been setting the standard for intuitive point-and-click software for scientists and engineers worldwide since 1991. Now our latest version of Origin raises the bar even higher. Built-in plot types allow you to quickly create 2D, 3D, contour, and image graphs. Intuitive analysis tools offer statistics, curve fitting, signal processing, and peak analysis. For ultimate power and flexibility, a completely integrated C compiler and over 300 NAG® functions are provided. New Features in ORIGIN 7.5 • Import Wizard visually provides step-by-step assistance to import data from ASCII and binary files • Graph Themes and Copy/Paste Format • Automatic Update of Worksheet Calculation1 • Data Transfer with MATLAB • Automation Server Support See a live Origin demonstration and download a Free Evaluation Copy at www.originlab.com MRC COMPUTING. Scientific Graphing and Analysis Software OriginLab Corporation USA: 1-800-969-7720 Origin is a registered trademark of OriginLab Corporation. One Roundhouse Plaza INT'L: +1-413-586-2013 FAX: 1-413-587-9915 NAG is a registered trademark of Numerical Algorithms Group. Northampton, MA 01060 USA EMAIL: [email protected] WEB: www.originlab.com MATLAB is a registered trademark of The MathWorks, Inc. NEWS NEW PARTICLES Four labs find five-quark particle Four international collaborations have particles generated were detected in the recently announced strong experimental CEBAF large-acceptance spectrometer. In the evidence for a five-quark exotic baryon named final state, the reaction produced a K" meson the theta-plus (0+), composed of two up and a proton, along with the five-quark quarks, two down quarks and a strange object, which then decayed into a neutron antiquark (uudds). Originally called the T by (identified by missing mass) and a K+ meson. the Particle Data Group, but renamed the 0+ The CLAS collaboration reports a 5.3 a 0+ in April this year, as suggested by Russian peak in the nK+ invariant mass spectrum at theorist Dmitri Diakonov, the exact nature of around 1542 MeV, with a measured width of the so-called "pentaquark" is not yet clear. 21 MeV. They have received approval for Further experiments should reveal whether it 30 days of beam time from the Program is a tightly bound five-quark object or a Advisory Committee, so as to characterize molecular meson-baryon state, and will fully the exotic 0+ baryon, and the provide measurements of its spin, and the experiment could be conducted as soon angular distribution and energy dependence as early 2004. of its production. The most recent experimental evidence for Physicists have searched for a five-quark Invariant mass of the (nK+) system obtained the pentaquark comes from the SAPHIR state for more than 35 years. Recent from CLAS using the reaction y+d^pK~(nK+). collaboration at the Electron Stretcher experimental efforts were largely motivated by The sharp peak at the mass of 1.542 GeV/c2 Accelerator (ELSA) in Bonn, Germany. Again Diakonov and colleagues Victor Petrov and has the exotic quantum number S = +1. The using older data, taken in 1997 and 1998, Maxim Polyakov. In 1997 they predicted an fit to the peak and a smooth background they measured the reaction yp^nKglC with exotic isoscalar baryon having spin-parity gives a significance of 5.8 o. The dotted the decay K°-^JT+JT~ in the SAPHIR detector (l/2)+and strangeness S =+1 (D Diakonov histogram shows the spectrum associated at ELSA. In an upcoming issue of Physics etal. 1997). In the antidecuplet of five- with A(1520) production. Letters B they report evidence for the 0+ in quark resonances that they predicted, the 0+ the invariant mass spectrum of the nK+ sys is the lowest mass member at about Meanwhile, the DIANA collaboration from tem (J Barth etal. 2003). They observe a 1530 MeV, having a width of less than the Institute of Theoretical and Experimental 4.8 a peak with a mass of 1540 MeV and a 15 MeV. The theorists suggested that the Physics (ITEP) in Moscow, Russia, was width of less than 25 MeV. After searching for particle would be seen as a sharp peak in the examining a 1986 data set from low-energy a signal in the pK+ invariant mass distribution nK+ or pK° mass spectrum.