motivation (predicted medium effects in the charm sector) Hadron modifications seen with electromagnetic probes Volker Metag II. Physikalisches Institut Universität Giessen Germany Observables in pp interactions and their relevance to QCD Workshop at ECT*,Trento, Italy, July 3-7, 2006 first observation of medium modifications of the meson: a.) mass shift b.) in-medium width in-medium spectral function s(,p) B 11 ω • first observation of an -nucleus bound state: • summary and outlook
35
Embed
motivation (predicted medium effects in the charm sector)
Hadron modifications seen with electromagnetic probes. Volker Metag II. Physikalisches Institut Universität Giessen Germany. in-medium spectral function s( ,p). first observation of an -nucleus bound state:. Observables in pp interactions and their relevance to QCD - PowerPoint PPT Presentation
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
• motivation (predicted medium effects in the charm sector)
Hadron modifications seen with electromagnetic probes
Hadron modifications seen with electromagnetic probes
Volker MetagII. Physikalisches Institut
Universität GiessenGermany
Observables in pp interactions and their relevance to QCDWorkshop at ECT*,Trento, Italy, July 3-7, 2006
• first observation of medium modifications of the meson: a.) mass shift b.) in-medium width in-medium spectral function s(,p)
B11ω
• first observation of an -nucleus bound state:
• summary and outlook
MotivationMotivation
widespread experimental activities to search for in-medium modifications of hadrons
Mas
s [G
eV]
• hadrons = excitations of the QCD vacuum
T.Hatsuda and S. Lee,PRC 46 (1992) R34
G.E.Brown and M. Rho,PRL 66 (1991) 2720
0
**
8.0qq
qq
mm
18.0;1mm
0
B
V
*V
• QCD-vacuum: complicated structure characterized by condensates
• in the nuclear medium: condensates are changed
change of the hadronic excitation energy spectrum
• in-medium mass shift (partial restoration of chiral symmetry, meson-baryon coupling)
possible in-medium modifications of hadronspossible in-medium modifications of hadrons
• in-medium broadening of hadron resonances (meson-baryon coupling, collisional broadening)
• hadron-nucleus bound states (meson-nucleus attractive potential)
model predictions for in-medium masses of mesonsmodel predictions for in-medium masses of mesons
K. Saito, K. Tushima, and A.W. ThomasPRC 55 (1997) 2637
Quark-meson coupling model (QMC)
decrease of -mass by 15%;decrease of D-mass by 3%at normal nuclear matter density
V. Bernard and U.-G. MeißnerNPA 489 (1988) 647
NJL-model
degeneracy of chiral partners
predictions in the charm sectorpredictions in the charm sector
consequences of a dropping D-meson mass
A. Hayashigaki, Phys. Lett. B 487 (2000) 96
QCD sum rules: mD - 50 MeV width of (3770) increases
2.7)MeV(23.6Γvac(3770)
on the other hand, Lee and Ko find:(S.H.Lee and C.M.Ko PRC67 (2003) 038202)
MeV38ΔmJ/ψ
MeV15140Δmψ(3770)
MeV30100Δmψ(2s)
from D-meson loops
(2s) may become instable to DD-decay
1.) lowering of in-medium mass 2.) broadening of resonance
for B
Model predictions for spectral functions of and mesonsModel predictions for spectral functions of and mesons
F. Klingl et al. NPA 610 (1997) 297 NPA 650 (1999) 299
Prediction of mesic states in QMC and QHD modelsPrediction of mesic states in QMC and QHD modelsK. Saito, K. Tsushima, A.W. Thomas, hep-ph/0506314
Search for mesic states in heavier nucleiSearch for mesic states in heavier nuclei
C. Garcia-Recio et al., PLB 550 (2002) 47unitarized chiral model
preferably only 1s-state24Mg: B=12.6 MeV; =33 MeV
experiment at COSY (ENSTAR/Big-Karl): Roy et al. : p 12C 3He + 10B; p 6Li 3He + 4Heexperiment at GSI: Hayano et al., EPJ A6 (1999) 105; 7Li(d,3He)6He; Td = 3.6GeV
Prediction of mesic statesPrediction of mesic states