Application of Straw Tube Detectors to Hyperon Studies Sedigheh Jowzaee Symposium on Applied Nuclear Physics and Innovative Technologies Sep. 2014, Krakow, Poland

“To know that we know what we know, and to know that we do not know what we do not know, that is true knowledge” Nicolaus Copernicus

Three generation of matter (fermions) I II III mass charge Spin name Current knowledge based on Standard Model of particle physics  Matter Quarks Leptons  Fundamental forces Gauge bosons Structure of Matter Stable matter

All observed color neutral hadrons ( (baryons), (mesons)) Baryons lightest three quark flavors (u,d,s) Hyperons Decuplet baryonsOctet baryons Hyperons: baryons contain s-quarks

Straw Tube Tracker (STT) The straw tube is a proportional counter, gas-filled cylindrical tube as a cathode and a thin wire as an anode stretched along the tube axis as an anode measure: t Drift  r Dis reconstruction of particle trajectory

STT in COSY-TOF Detector Λ K+K+ π-π- p p Hyperon study in pp pK + Λ reaction Strange quark does not exist in nucleon as a constituent How they create and how they interact COSY-TOF detector is Excellent for strangeness study Upgraded with STT High statistics measurement Beam momentum= 2.95 GeV/c Polarization (87.5 ± 2.0)% Reconstruction of events with STT 140 μm spatial resolution reconstructed events 20 % reconstruction efficiency with MC Invariant mass resolution 1 MeV/c 2

COSY-TOF STT Calibration Reconstruction of pK + Λ events with STT precise calibration Calibration steps TDC correction Multiple hits removal, Signal width cut, Electronics offset correction Estimation of correlation between drift time and radius Straw double layers geometrical position correction Spatial resolution determination Published: S. Jowzaee, Acta physica polonica B, Vol. 6, (2013).

pK + Λ Dalitz Plot and Projections The experiment covers the complete kinematic phase space Interference between physical effects in KΛ and pΛ subsystems Nucleon excited states (N*-resonances) NΛ interaction (pΛ-FSI ) NΣ-pΛ coupled channel effect (NΣ cusp) Prepare publication

STT in PANDA Detector PANDA and Charmonium study Charm quark is heavier than strange quark higher beam momentum, pp reaction STT is a main tracker in the PANDA detector STT performance simulation for PID with TOT and charge methods Published: S. Jowzaee, et al., Nuclear Instruments and methods in physics research A 718, (2013).

Summary Modular straw tube trackers are good tools for tracking and particles identification in large scale experiments like the COSY-TOF and the PANDA COSY-TOF upgraded with STT is an ideal detector to study Λ-hyperon in the pp pK + Λ reaction An improved invariant mass distribution and reconstruction efficiency were obtained due to the straw tube tracker performance

Thank you INTERNATIONAL PHD PROJECTS IN APPLIED NUCLEAR PHYSICS AND INNOVATIVE TECHNOLOGIES This project is supported by the Foundation for Polish Science – MPD program, co-financed by the European Union within the European Regional Development Fund

pK + Λ Dalitz Plot Analysis Cusp effect is stronger at lower parts of the Dalitz plot FSI effect seems to be same in three parts in the low enough range of the m pΛ Dividing the Dalitz plot into three equal phase space volume sections by helicity angle cosθ pK in pΛ rest frame Prepare publication