Search for glueballs with the Crystal Barrel detector at LEAR/CERN

Search for glueballs with the Crystal Barrel detector at LEAR/CERN by Jan Kisiel Download PDF EPUB FB2

The Crystal Barrel Search for the 2++ Glueball The Crystal Barrel detector is well known [iOJ. With its CsI hermatic calorimeter it is an excellent detector of photons.

In the last days of LEAR operation a fine scan was made at CB with the all-neutral trigger to search for ~() in the mass region to by: 2. A high resolution search for the tensor glueball candidate [xi] () Crystal Barrel Collaboration. "Physics Letters B" (Vol.iss.

(), s. ), doi /S(01) p¯p annihilation experiment, PS, made with the Crystal Barrel detector [6] at the LEAR facility at CERN.

In order to provide the appropriate perspective for our choice of the method of. The Crystal Barrel is a new detector which will combine good tracking and electromagnetic calorimetry over nearly the full solid angle. The detector will be located at the C2-beam line of the Low Energy Antiproton Ring (LEAR) at CERN.

We will take data at cm-energies between √s= GeV (i.e. stopping antiprotons) and √s= GeV. vations are a search for glueballs and other exotic mesons and a determination of branching ratios for annihilation into various final states which are relevant to low energy QCD inspired phenomenology.

2 Status of the apparatus Following last year's set-up the Crystal Barrel is. ZUrich 66 AI A Kunze et al. / Crystal barrel detector at LEAR 1 Physics Aims Meson Spectroscopy Antiproton-proton annihilation at rest and m flight is a rich source of meson production.

With the Crystal Barrel detector, we will search for final states pp -> ~ (~) + X, where X denotes a mesonic resonant intermediate state, decaying into.

The Crystal Barrel detector at the LEAR antiproton facility has been described in detail elsewhere.9> In brief it consists of a near hermetic 47r detector for photons and charged particles produced in p intereactions with a 4 cm long target of liquid hydrogen.

For the present measurements an all neutral trigger was used and the an­. Most recent experimental e#orts have been directed to the search and identification of these two, the scalar and the tensor glueballs [5]. In this letter we present the results of a high resolution search for the 2 tensor glueball in a pp annihilation experiment, PS, made with the Crystal Barrel detector [6] at the LEAR facility at CERN.

For this purpose, annihilation data has been tak en with the Crystal Barrel detector system [7] at LEAR (CERN) with an antiproton beam impinging on a liquid hydrogen tar get at the maxi- mum beam.

This report shows first results obtained with the Crystal Barrel detector system at LEAR (CERN) at an antiproton beam momentum of MeV/c. Introduction One outstanding issue in meson spectroscopy is whether there exist hadrons with explicit gluonic degrees of freedom. with the Crystal Barrel⁄ Claude Amsler Physik-Institut der Universit˜at Z˜urich, WinterthurerstrasseCH Z˜urich, Switzerland June 2, Abstract This report reviews the achievements of the Crystal Barrel experiment at the Low Energy Antiproton Ring (LEAR) at CERN.

During seven years of operation Crystal Barrel has collected. The detector which may have found this glueball, called Crystal Barrel, faces closure because CERN is now concentrating its efforts on its next huge machine, the Large Hadron Collider.

New results from LEAR experiments on the search for glueballs and other non- states have attracted considerable attention, particularly the discovery of the (), which is an excellent candidate for the scalar glueball.

This article gives an overview about the special features of annihilation for meson spectroscopy, and about the use of initial and final-state selection for quantum-number. Results of a search for the tensor (2++) glueball candidate ξ() are presented. A scan of the formation of ξ() in the mass region s=− MeV/c2 was made using the Crystal Barrel.

Spectroscopy and decays of glueballs, hybrids and light mesons and dynamics of NN annihilations at LEAR at ACOL time with OBELIX, a complete 4 *• detector based on the Open Axial Field Spectrometer.

pp annihilation at LEAR with»4» neutral detector. Csl Crystal Barrel at LEAR. A high resolution and high rate detector for LEAR.

The activities of this group are primarily concerned with experiments using the Crystal Barrel Detector. This detector is installed and operating at the Low Energy Antiproton Ring (LEAR) at CERN.

QCD, the modern theory of the strong interaction, is reasonably well understood at high energies, but unfortunately, low-energy QCD is still not well understood, and is far from being adequately tested.

Section III presents the new meson spectroscopy experiments in pre­ paration at CERN and Fermilab: Crystal Barrel, OBELIX, Jetset and E Section IV is dedicated to LEAR and to future facilities where meson spectroscopy would be a principal component of the physics programme. Data was taken with the Crystal Barrel detector at LEAR at CERN.

events of the reaction pbar p -> 2π ^ + 2π ^ - η were fitted and the branching ratio of the reaction pbar p -> π ^ + π ^ - η ({} ;) determined to (±) The partial wave analysis shows clear evidence for a η() and also hints for the η().

with the Crystal Barrel detector system at LEAR (CERN) at an antiproton beam momentum of MeV/c. Introduction One outstanding issue in meson spectroscopy is whether there exist hadrons with explicit gluonic degrees of freedom.

The discovery of such exotic hadrons like hybrids (qqg) and glueballs. ered by the Crystal Barrel experiment at the CERN Low-Energy Antiproton Ring (LEAR), has a width of Γ ≈ MeV and has been observed to decay to π0π0,ηη[13], ηη′ [14] and KK¯ [15] following ppannihilation at rest.

The existence of this state has been confirmed in in-flight ¯pp annihilations by experiment E at Fermilab [16]. It. PWA with Crystal Barrel Data Crystal Barrel experiment @ LEAR (CERN) (1) Iron Joke, (2) Magnet Coil (3) CsI(Tl)-Calorimeter, (4) Jet-Drift-Chamber (5) Vertex-Detector, (6) LH 2-Target Fixed target experiment pp annihilation at rest and in flight highest beam momentum GeV/c overlap with PANDA Physics program.2 The Crystal Barrel Experiment The Crystal Barrel experiment ran at the LEAR 1, from till and studied pp annihilations both at rest and in ight.

The detector is a nearly 4ˇ, high resolution system for both charged particles and photons. One of the main goals of the experiment was to search for gluonic exciations in the meson spectrum.The Crystal{Barrel Detector at LEAR (CERN) { Meson spectroscopy in pp reactions at rest and the search for exotic states The Crystal{Barrel Experiment at ELSA: initial con guration (/) Problem: predicted glueballs can mix with ordinary qq states + with S= 1 with Q= 2.