0000000000147098
AUTHOR
E. Kabuß
showing 4 related works from this author
Search for muoproduction of X(3872) at COMPASS and indication of a new state X˜(3872)
2018
Abstract We have searched for exclusive production of exotic charmonia in the reaction μ + N → μ + ( J / ψ π + π − ) π ± N ′ using COMPASS data collected with incoming muons of 160 GeV/c and 200 GeV/c momentum. In the J / ψ π + π − mass distribution we observe a signal with a statistical significance of 4.1 σ. Its mass and width are consistent with those of the X ( 3872 ) . The shape of the π + π − mass distribution from the observed decay into J / ψ π + π − shows disagreement with previous observations for X ( 3872 ) . The observed signal may be interpreted as a possible evidence of a new charmonium state. It could be associated with a neutral partner of X ( 3872 ) with C = − 1 predicted b…
Study of Σ(1385) and Ξ(1321) hyperon and antihyperon production in deep inelastic muon scattering
2013
Large samples of \Lambda, \Sigma(1385) and \Xi(1321) hyperons produced in deep-inelastic muon scattering off a ^6LiD target were collected with the COMPASS experimental setup at CERN. The relative yields of \Sigma(1385)^+, \Sigma(1385)^-, \bar{\Sigma}(1385)^-, \bar{\Sigma}(1385)^+, \Xi(1321)^-, and \bar{\Xi}(1321)^+ hyperons decaying into \Lambda(\bar{\Lambda})\pi were measured. The heavy hyperon to \Lambda and heavy antihyperon to \bar{\Lambda} yield ratios were found to be in the range 3.8% to 5.6% with a relative uncertainty of about 10%. They were used to tune the parameters relevant for strange particle production of the LEPTO Monte Carlo generator.
Triangle Singularity as the Origin of the a1(1420)
2021
The COMPASS Collaboration experiment recently discovered a new isovector resonancelike signal with axial-vector quantum numbers, the a 1 ( 1420 ) , decaying to f 0 ( 980 ) π . With a mass too close to and a width smaller than the axial-vector ground state a 1 ( 1260 ) , it was immediately interpreted as a new light exotic meson, similar to the X , Y , Z states in the hidden-charm sector. We show that a resonancelike signal fully matching the experimental data is produced by the decay of the a 1 ( 1260 ) resonance into K * ( → K π ) K ¯ and subsequent rescattering through a triangle singularity into the coupled f 0 ( 980 ) π channel. The amplitude for this process is calculated using a new a…
The COMPASS experiment at CERN
2007
The COMPASS experiment makes use of the CERN SPS high-intensitymuon and hadron beams for the investigation of the nucleon spin structure and the spectroscopy of hadrons. One or more outgoing particles are detected in coincidence with the incoming muon or hadron. A large polarized target inside a superconducting solenoid is used for the measurements with the muon beam. Outgoing particles are detected by a two-stage, large angle and large momentum range spectrometer. The setup is built using several types of tracking detectors, according to the expected incident rate, required space resolution and the solid angle to be covered. Particle identification is achieved using a RICH counter and both…