scholarly journals CHIRAL UNITARY APPROACH TO HADRON SPECTROSCOPY

2003 ◽  
Vol 18 (03) ◽  
pp. 387-396 ◽  
Author(s):  
E. Oset ◽  
T. Inoue ◽  
M. J. Vicente Vacas ◽  
A. Ramos ◽  
C. Bennhold
Keyword(s):  
Complex Plane ◽  
Final States ◽  
S Wave ◽  
Baryon Interaction ◽  
Hadron Spectroscopy ◽  
Dynamical Generation ◽  
Coupled Channels ◽  
Unitary Approach ◽  
Chiral Unitary Approach ◽  
Chiral Lagrangian

The s-wave meson-baryon interaction in the S = -1, S = 0 and S = -2 sectors is studied by means of coupled channels, using the lowest-order chiral Lagrangian and the N/D method or equivalently the Bethe-Salpeter equation to implement unitarity. This chiral approach leads to the dynamical generation of the Λ(1405), Λ(1670) and Σ(1620) states for S = -1, the N*(1535) for S = 0 and the Ξ(1620) for S = -2. We look for poles in the complex plane and extract the couplings of the resonances to the different final states. This allows identifying the Λ(1405) and the Λ(1670) resonances with [Formula: see text] and K Ξ quasibound states, respectively. Our results are found to be incompatible with the measured properties of the Ξ(1690) resonance, thus ruling this state out as the remaining member of this octet of dynamically generated resonances. We therefore assign 1/2- for the spin and parity of the Ξ(1620) resonance as the S = -2 member of the lowest-lying 1/2- octet.

HADRONIC DECAYS OF η AND η′

2005 ◽  
Vol 20 (02n03) ◽  
pp. 546-548
Author(s):  
B. BORASOY ◽  
N. BEISERT
Keyword(s):  
Hadronic Decays ◽  
S Wave ◽  
Final State ◽  
Effective Lagrangian ◽  
Unitary Approach ◽  
Final State Interactions ◽  
Small Set ◽  
Chiral Unitary Approach ◽  
Spectral Shapes

The hadronic decays η→πππ, η′→πππ and η′→ηππ are investigated within a U(3) chiral unitary approach. Final state interactions are included by deriving the effective s wave potentials for meson meson scattering from the chiral effective Lagrangian and iterating them in a Bethe-Salpeter equation. With only a small set of parameters we are able to explain both rates and spectral shapes of these decays.

scholarly journals Tau decay into $$\nu _\tau $$ and $$a_1(1260)$$, $$b_1(1235)$$, and two $$K_1(1270)$$

2020 ◽  
Vol 80 (7) ◽  
Author(s):  
L. R. Dai ◽  
L. Roca ◽  
E. Oset
Keyword(s):  
Axial Vector ◽  
S Wave ◽  
Decay Channels ◽  
Quantum Numbers ◽  
Present Information ◽  
Unitary Approach ◽  
One Step ◽  
Chiral Unitary Approach ◽  
Cabibbo Suppressed ◽  
Good Agreement

Abstract We study the $$\tau \rightarrow \nu _\tau A$$τ→ντA decay, with A an axial-vector meson. We produce the $$a_1(1260)$$a1(1260) and $$b_1(1235)$$b1(1235) resonances in the Cabibbo favored mode and two $$K_1(1270)$$K1(1270) states in the Cabibbo suppressed mode. We take advantage of previous chiral unitary approach results where these resonances appear dynamically from the vector and pseudoscalar meson interaction in s-wave. Actually two different poles were obtained associated to the $$K_1(1270)$$K1(1270) quantum numbers. We find that the unmeasured rates for $$b_1(1235)$$b1(1235) production are similar to those of the $$a_1(1260)$$a1(1260) and for the two $$K_1$$K1 states we suggest to separate the present information on the $$\bar{K} \pi \pi $$K¯ππ invariant masses into $$\bar{K}^* \pi $$K¯∗π and $$\rho K$$ρK modes, the channels to which these two resonances couple most strongly, predicting that these modes peak at different energies and have different widths. These measurements should shed light on the existence of these two $$K_1$$K1 states. In addition, we have gone one step further making a comparison with experimental results of three meson decay channels, letting the vector mesons of our approach decay into pseudoscalars, and we find an overall good agreement with experiment.

scholarly journals A STUDY OF THE πN SCATTERING DATA WITH JP = 3/2- AND A PROOF OF THE EXISTENCE OF THE N*(1700)

2014 ◽  
Vol 26 ◽  
pp. 1460061
Author(s):  
E. J. GARZON ◽  
JUJUN XIE ◽  
E. OSET
Keyword(s):  
Experimental Data ◽  
Complex Plane ◽  
Scattering Data ◽  
S Wave ◽  
Wave Data ◽  
Coupled Channels ◽  
Free Parameters ◽  
Coupled Channel ◽  
D Wave

Using an interaction extracted from the local hidden gauge Lagrangians and the coupled channels ρN (s-wave), πN (d-wave), πΔ (s-wave) and πΔ (d-wave), we look in the region of [Formula: see text] and we find two resonances dynamically generated which are naturally associated to the N*(1520)(3/2-) and N*(1700)(3/2-). The N*(1700)(3/2-) appears neatly as a pole in the complex plane. The free parameters of the theory are chosen to fit the πN (d-wave) data. The unitary coupled channel approach followed here, in connection with the experimental data, leads automatically to a pole in the 1700 MeV region and makes this second 3/2- resonance unavoidable.

scholarly journals Effect of coupled channels of the multi-channel pion-pion scattering in two-pion transitions of the Υ mesons

2015 ◽  
Vol 39 ◽  
pp. 1560090
Author(s):  
Yurii S. Surovtsev ◽  
Petr Bydžovský ◽  
Thomas Gutsche ◽  
Robert Kamiński ◽  
Valery E. Lyubovitskij ◽  
...  
Keyword(s):  
Scattering Amplitudes ◽  
Mass Spectra ◽  
Final States ◽  
S Wave ◽  
Wave Processes ◽  
Crystal Ball ◽  
Combined Analysis ◽  
Pion Scattering ◽  
Scalar Mesons ◽  
Coupled Channels

The effect of isoscalar S-wave processes [Formula: see text] is considered in the analysis of data (from the ARGUS, CLEO, CUSB, Crystal Ball, Belle, BABAR collaborations) on the bottomonia decays — [Formula: see text] ([Formula: see text]). It is shown that the dipion mass spectra of these decays are explained by the unified mechanism related to the contribution of the multichannel [Formula: see text] scattering in the final states of these reactions. Since in the analysis the multichannel [Formula: see text]-scattering amplitudes did not change in comparison with the ones in our combined analysis of data on the multichannel [Formula: see text] scattering and on the charmonia decays — [Formula: see text] and [Formula: see text] (from the Crystal Ball, DM2, Mark II, Mark III, and BES II) — the results confirm all our earlier conclusions on the scalar mesons.

scholarly journals DYNAMICALLY GENERATED RESONANCES IN THE CHIRAL UNITARY APPROACH TO MESON BARYON INTERACTION

2005 ◽  
Vol 20 (08n09) ◽  
pp. 1619-1626 ◽  
Author(s):  
E. OSET ◽  
S. SARKAR ◽  
M. J. VICENTE VACAS ◽  
A. RAMOS ◽  
D. JIDO ◽  
...  
Keyword(s):  
Scattering Matrix ◽  
Baryon Interaction ◽  
First Case ◽  
Show Evidence ◽  
Unitary Approach ◽  
Chiral Unitary Approach ◽  
Exotic Baryon

In this talk we report on the use of a chiral unitary approach for the interaction of the octets of meson and baryon and the octet of mesons with the decuplet of baryons. Two octets of Jπ=1/2- baryon states and a singlet are generated dynamically in the first case, resulting in the case of strangeness S=-1 in two poles of the scattering matrix close to the nominal Λ(1405) resonance. In the second case many resonances are also generated, among them an exotic baryon with S=1 corresponding to a ΔK resonance. We make suggestions of experiments which could show evidence for the existence of these states.

scholarly journals Study the $$B^{0}_{(s)}$$ decays into $$\phi $$ and a scalar or vector meson

2021 ◽  
Vol 81 (8) ◽  
Author(s):  
Hiwa A. Ahmed ◽  
Zhong-Yu Wang ◽  
Zhi-Feng Sun ◽  
C. W. Xiao
Keyword(s):  
Invariant Mass ◽  
Final State Interaction ◽  
Branching Ratios ◽  
State Interaction ◽  
Final State ◽  
Decay Channels ◽  
Mass Distributions ◽  
Coupled Channels ◽  
Unitary Approach ◽  
Chiral Unitary Approach

AbstractIn the present work, we investigate the decays of $$B^{0}_{(s)} \rightarrow \phi \pi ^{+}\pi ^{-}$$ B ( s ) 0 → ϕ π + π - with the final state interaction based on the chiral unitary approach. In the final state interaction of the $$\pi ^+\pi ^-$$ π + π - with its coupled channels, we study the effects of the $$\eta \eta $$ η η channel in the two-body interaction for the reproduction of the $$f_{0}(980)$$ f 0 ( 980 ) state, where its contribution to the $$f_{0}(980)$$ f 0 ( 980 ) state can be ignored. Our results for the $$\pi ^+\pi ^-$$ π + π - invariant mass distributions of the decay $$B^{0}_{s} \rightarrow \phi \pi ^{+}\pi ^{-}$$ B s 0 → ϕ π + π - describe the experimental data up to 1 GeV well, with the resonance contributions from the $$f_{0}(980)$$ f 0 ( 980 ) and $$\rho $$ ρ . For the predicted invariant mass distributions of the $$B^{0} \rightarrow \phi \pi ^{+}\pi ^{-}$$ B 0 → ϕ π + π - decay, we find that the contributions from the $$f_{0}(500)$$ f 0 ( 500 ) are significant, but not from the $$f_{0}(980)$$ f 0 ( 980 ) state. With some experimental branching ratios to determine the production vertex factors, we make predictions for the branching ratios of the other decay channels, including the vector mesons, in the $$B^0_{(s)}$$ B ( s ) 0 decays, some of which are consistent with the experimental measurements within the uncertainties.

EXTRACTION OF THE Λ(1405) POLES FROM π0Σ0 PHOTOPRODUCTION DATA

2014 ◽  
Vol 26 ◽  
pp. 1460086
Author(s):  
L. ROCA ◽  
E. OSET
Keyword(s):  
Scattering Amplitudes ◽  
Linear Combination ◽  
Photonuclear Reaction ◽  
Jefferson Lab ◽  
Coupled Channels ◽  
Unitary Approach ◽  
Chiral Unitary Approach ◽  
Free Parameters ◽  
Photoproduction Data

In this contribution we review a work where we showed how to extract the position of the two Λ(1405) poles from experimental photoproduction data which have been measured recently in the γp → K+π0Σ0 reaction at Jefferson Lab. Using a potential motivated by chiral dynamics but with free parameters, we solve the Bethe Salpeter equation in the coupled channels [Formula: see text] and πΣ in isospin I=0 and parameterize the amplitude for the photonuclear reaction in terms of a linear combination of the πΣ → πΣ and [Formula: see text] scattering amplitudes in I=0, with a different linear combination for each energy. Good fits to the data are obtained which lead to two poles at 1385 - 68i MeV and 1419 - 22i MeV, similar to those found in the chiral unitary approach.

scholarly journals Dynamical generation of Floquet Majorana flat bands in s-wave superconductors

2015 ◽  
Vol 110 (1) ◽  
pp. 17004 ◽  
Author(s):  
A. Poudel ◽  
G. Ortiz ◽  
L. Viola
Keyword(s):  
S Wave ◽  
Flat Bands ◽  
Dynamical Generation

scholarly journals Role of N*(1535) in the Λ+c → K0ηp decay and the possible фp state in the Λ+c → π0фp decay

2020 ◽  
Vol 241 ◽  
pp. 02010
Author(s):  
Ju-Jun Xie ◽  
Li-Sheng Geng ◽  
Feng-Kun Guo
Keyword(s):  
Invariant Mass ◽  
Mass Distribution ◽  
Final State Interaction ◽  
Invariant Mass Distribution ◽  
Lagrangian Model ◽  
Final State ◽  
Peak Structure ◽  
Effective Lagrangian ◽  
Unitary Approach ◽  
Chiral Unitary Approach

The nonleptonic weak decays of Λ+c → K0ηp and Λ+c → π0фp are investigated from the viewpoint of probing the N*(1535) resonance and the possible фp state. For the Λ+c → K0ηp decay, we study the invariant mass distribution of ηp with both the chiral unitary approach and an effective Lagrangian model. Within the chiral unitary approach, the N*(1535) resonance is dynamically generated from the final state interaction of mesons and baryons in coupled channels. While for the effective Lagrangian model, we take a Breit-Wigner formula for the N*(1535) resonance. We found that the behavior of the N*(1535) resonance in the Λ+c → K0N*(1535) → K0ηp decay within the two approaches is different. For the Λ+c → π0фp decay, we consider a triangle singularity mechanism, where the Λ+c decays into the K*Σ*(1385), the Σ*(1385) decays into the π0Σ/Λ, and then the K*Σ/Λ merge to produce the фp in the final state. This mechanism produces a peak structure around 2020 MeV. In addition, the possibility that there is a hidden-strange pentaquark-like state is also considered by taking into account the final state interactions of K*Λ, K*Σ, and фp. We conclude that it is difficult to search for the hidden-strange state in this decay. However, we do expect nontrivial behavior in the фp invariant mass distribution. The proposed Λ+c decay mechanism here can provide valuable information on the properties of these nuclear resonances and can in principle be tested by experiments such as BESIII, LHCb and Belle-II.

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