scholarly journals Role of baryon resonances in the π−p→ne+e− reaction within an effective-Lagrangian model

2021 ◽  
Vol 104 (1) ◽  
Author(s):  
Miklós Zétényi ◽  
Deniz Nitt ◽  
Michael Buballa ◽  
Tetyana Galatyuk
Keyword(s):  
Lagrangian Model ◽  
Effective Lagrangian ◽  
Baryon Resonances

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.

THE ROLE OF THE GHOST FIELDS IN THE RENORMALIZED t–J LAGRANGIAN MODEL

2009 ◽  
Vol 23 (04) ◽  
pp. 493-519
Author(s):  
O. S. ZANDRON
Keyword(s):  
Thermal Softening ◽  
Lagrangian Model ◽  
Lagrangian Formalism ◽  
Spin Polaron ◽  
Renormalization Procedure ◽  
Ghost Field

The present work treats the role of ghost fields in the renormalization procedure of the Lagrangian perturbative formalism of the t–J model. We show that by introducing proper ghost field variables, the propagators and vertices can be renormalized to each order. In particular, the renormalized ferromagnetic magnon propagator coming from our previous Lagrangian formalism is studied in detail, and it is shown how the thermal softening of the magnon frequency is predicted by the model. The antiferromagnetic case is also analyzed, and the results are confronted with the previous one obtained by means of the spin-polaron theories.

scholarly journals KÄHLER STABILIZED, MODULAR INVARIANT HETEROTIC STRING MODELS

2007 ◽  
Vol 22 (08n09) ◽  
pp. 1451-1588 ◽  
Author(s):  
MARY K. GAILLARD ◽  
BRENT D. NELSON
Keyword(s):  
Heterotic String ◽  
Target Space ◽  
Modular Invariant ◽  
Heterotic String Theory ◽  
Effective Lagrangian ◽  
Parity Conservation ◽  
Weakly Coupled ◽  
String Models ◽  
Early Universe Cosmology

We review the theory and phenomenology of effective supergravity theories based on orbifold compactifications of the weakly-coupled heterotic string. In particular, we consider theories in which the four-dimensional theory displays target space modular invariance and where the dilatonic mode undergoes Kähler stabilization. A self-contained exposition of effective Lagrangian approaches to gaugino condensation and heterotic string theory is presented, leading to the development of the models of Binétruy, Gaillard and Wu. Various aspects of the phenomenology of this class of models are considered. These include issues of supersymmetry breaking and superpartner spectra, the role of anomalous U(1) factors, issues of flavor and R-parity conservation, collider signatures, axion physics, and early universe cosmology. For the vast majority of phenomenological considerations the theories reviewed here compare quite favorably to other string-derived models in the literature. Theoretical objections to the framework and directions for further research are identified and discussed.

Baryonic Interactions in an Effective-Lagrangian Model

1972 ◽  
Vol 6 (5) ◽  
pp. 1453-1455
Author(s):  
Ashok Kumar Bhargava
Keyword(s):  
Lagrangian Model ◽  
Effective Lagrangian

scholarly journals THE EFFECT OF ELECTROMAGNETIC PROPERTIES OF NEUTRINOS ON THE PHOTON–NEUTRINO DECOUPLING TEMPERATURE

2012 ◽  
Vol 27 (32) ◽  
pp. 1250187
Author(s):  
S. C. İNAN ◽  
M. KÖKSAL
Keyword(s):  
Lagrangian Model ◽  
Electromagnetic Properties ◽  
Beyond The Standard Model ◽  
Ultrahigh Energy ◽  
Qcd Phase Transition ◽  
Effective Lagrangian ◽  
Independent Analysis ◽  
The Standard Model ◽  
Model Independent ◽  
The Impact

We examine the impact of electromagnetic properties of neutrinos on the annihilation of relic neutrinos with ultrahigh energy cosmic neutrinos for the [Formula: see text] process. For this process, photon–neutrino decoupling temperature is calculated via effective Lagrangian model beyond the standard model. We find that photon–neutrino decoupling temperature can be importantly reduced below the QCD phase transition with the model independent analysis defining electromagnetic properties of neutrinos.

scholarly journals The role of N*(2120) nucleon resonance in KΛ(1520) photon and hadronic productions

2014 ◽  
Vol 29 ◽  
pp. 1460244
Author(s):  
Ju-Jun Xie ◽  
En Wang ◽  
Bo-Chao Liu ◽  
J. Nieves
Keyword(s):  
Experimental Data ◽  
Invariant Mass ◽  
Cross Sections ◽  
Dalitz Plot ◽  
Total Cross Sections ◽  
Effective Lagrangian ◽  
Hadronic Production ◽  
Current Experimental Data ◽  
Theoretical Results

The associate KΛ(1520) photon and hadronic production in the γp → K+Λ(1520), pp → pK+Λ(1520) and π-p → K0Λ(1520) reactions are investigated within the effective Lagrangian approach and the isobar model. We are interested in the contribution from the N*(2120) (previously called N*(2080)) resonance, which has a significant coupling to the KΛ(1520) channel. The theoretical results show that the current experimental data for the γp → K+Λ(1520) reaction favor the existence of the N*(2120) resonance, and that these measurements can be used to further constrain its properties. We present results, including the N*(2120) contribution, for total cross sections of the γp → K+Λ(1520), π-p → K0Λ(1520), and pp → pK+Λ(1520) reactions. For this latter one, we also calculate invariant mass and Dalitz plot distributions.

IMPROVED BOUNDS ON THE TAU MAGNETIC MOMENTS

2001 ◽  
Vol 16 (supp01b) ◽  
pp. 545-547 ◽  
Author(s):  
GABRIEL A. GONZÁLEZ-SPRINBERG ◽  
ARCADI SANTAMARIA ◽  
JORGE VIDAL
Keyword(s):  
Standard Model Prediction ◽  
Magnetic Moments ◽  
W Bosons ◽  
Lagrangian Model ◽  
Tau Leptons ◽  
Effective Lagrangian ◽  
Order Of Magnitude ◽  
Magnetic Couplings ◽  
Using Data ◽  
First Time

New limits on the tau magnetic couplings to the photon, the Z and the W bosons are obtained from the most general effective Lagrangian. Model independent bounds are set using data for tau pair production and W decay into tau leptons at LEP1, LEP2, SLD and hadron colliders. For the anomalous magnetic moment the bounds are, for the first time, of the order of magnitude of the standard model prediction.

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