scholarly journals COUPLED CHANNEL EFFECTS IN ππ S-WAVE INTERACTION

2005 ◽  
Vol 20 (08n09) ◽  
pp. 1905-1909 ◽  
Author(s):  
F. Q. WU ◽  
B. S. ZOU
Keyword(s):  
Wave Scattering ◽  
Wave Interaction ◽  
Matrix Formalism ◽  
S Wave ◽  
Coupled Channels ◽  
Channel Effects ◽  
Scattering Phase ◽  
Scattering Phase Shifts ◽  
Coupled Channel ◽  
K Matrix

We study coupled channel effects upon isospin I=2 and I=0 ππ S-wave interaction. With introduction of the ππ→ρρ→ππ coupled channel box diagram contribution into ππ amplitude in addition to ρ and f2(1270) exchange, we reproduce the ππ I =2 S-wave and D-wave scattering phase shifts and inelasticities up to 2 GeV quite well in a K-matrix formalism. For I=0 case, the same ππ→ρρ→ππ box diagram is found to give the largest contribution for the inelasticity among all possible coupled channels including ππ→ωω→ππ, [Formula: see text]. We also show why the broad σ appears narrower in production processes than in ππ scattering process.

Estimating the error in variational scattering calculations

1978 ◽  
Vol 56 (10) ◽  
pp. 1358-1364 ◽  
Author(s):  
J. W. Darewych ◽  
R. Pooran
Keyword(s):  
Wave Scattering ◽  
Exponential Potential ◽  
S Wave ◽  
Order Error ◽  
Absolute Value ◽  
First Order ◽  
Scattering Phase ◽  
Square Well ◽  
Scattering Phase Shifts ◽  
Made In

We derive bounds to the absolute value of the error that is made in variational estimates of scattering phase shifts. These bounds, like the variational estimates, are second order in 'small' quantities and are, in this respect, an improvement on similar but first-order error bounds derived previously by Bardsley, Gerjuoy, and Sukumar. The s-wave scattering by a square well potential, in the Born approximation, and by an exponential potential, using a many parameter trial function, are used to illustrate the results.

PRECISE MEASUREMENTS OF S-WAVE SCATTERING PHASE SHIFTS WITH A JUGGLING ATOMIC CLOCK

2009 ◽  
Author(s):  
STEVEN GENSEMER ◽  
RUSSELL HART ◽  
ROSS MARTIN ◽  
XINYE XU ◽  
RONALD LEGERE ◽  
...  
Keyword(s):  
Wave Scattering ◽  
Atomic Clock ◽  
Phase Shifts ◽  
S Wave ◽  
Scattering Phase ◽  
Scattering Phase Shifts

PRECISE MEASUREMENTS OF S-WAVE SCATTERING PHASE SHIFTS WITH A JUGGLING ATOMIC CLOCK

2009 ◽  
Author(s):  
STEVEN GENSEMER ◽  
RUSSELL HART ◽  
ROSS MARTIN ◽  
XINYE XU ◽  
RONALD LEGERE ◽  
...  
Keyword(s):  
Wave Scattering ◽  
Atomic Clock ◽  
Phase Shifts ◽  
S Wave ◽  
Scattering Phase ◽  
Scattering Phase Shifts

scholarly journals Nπ scattering in the Roper channel

2018 ◽  
Vol 175 ◽  
pp. 05004
Author(s):  
M. Padmanath ◽  
C. B. Lang ◽  
Luka Leskovec ◽  
Sasa Prelovsek
Keyword(s):  
Lattice Qcd ◽  
Positive Parity ◽  
Roper Resonance ◽  
S Wave ◽  
Lattice Spectrum ◽  
Lattice Calculations ◽  
Channel Effects ◽  
Technical Details ◽  
Elastic Approximation ◽  
Coupled Channel

We present results from our recent lattice QCD study of Nπ scattering in the positive-parity nucleon channel, where the puzzling Roper resonance N*(1440) resides in experiment. Using a variety of hadron operators, that include qqq-like, Nπ in p-wave and Nσ in s-wave, we systematically extract the excited lattice spectrum in the nucleon channel up to 1.65 GeV. Our lattice results indicate that Nπ scattering in the elastic approximation alone does not describe a low-lying Roper. Coupled channel effects between Nπ and Nππ seem to be crucial to render a low-lying Roper in experiment, reinforcing the notion that this state could be a dynamically generated resonance. After giving a brief motivation for studying the Roper channel and the relevant technical details to this study, we will discuss the results and the conclusions based on our lattice investigation and in comparison with other lattice calculations.

Interacting Hadron resonance gas model within S-matrix formalism

2019 ◽  
Vol 28 (09) ◽  
pp. 1940001 ◽  
Author(s):  
Ashutosh Dash ◽  
Subhasis Samanta
Keyword(s):  
Virial Coefficients ◽  
Heavy Ion ◽  
Phase Shifts ◽  
Matrix Formalism ◽  
Ion Collisions ◽  
S Matrix ◽  
Scattering Phase ◽  
Thermodynamic Variables ◽  
K Matrix ◽  
Dynamical Information

A noninteracting hadron resonance gas model is used often to study the hadronic phase formed in heavy ion collisions. Interaction among various hadronic constituents can be included using an S-matrix-based virial expansion approach. The virial coefficients require the dynamical information about the scattering phase shifts, which is used to compute various thermodynamic observables of an interacting hadronic gas. The attractive part of the phase shifts are calculated using K-matrix formalism while the repulsive part is obtained by fitting to experimental data. Calculation of various thermodynamic variables like pressure, energy density, specific heat capacity, etc., along with the second and higher-order correlations and fluctuations of conserved charges are done, first with only attraction and then with both attraction and repulsion included. Comparison of S-matrix results indicate a better agreement with lattice QCD data than the ideal HRG model across all thermodynamic variables.

Coupled channel study on the S-wave interaction

1974 ◽  
Vol 68 (2) ◽  
pp. 397-412 ◽  
Author(s):  
N.O. Johannesson ◽  
J.L. Petersen
Keyword(s):  
Wave Interaction ◽  
S Wave ◽  
Coupled Channel
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