scholarly journals NUCLEAR EFFECTS IN NEUTRINO INDUCED REACTIONS

2008 ◽  
Vol 23 (27n30) ◽  
pp. 2321-2324
Author(s):  
M. J. VICENTE VACAS ◽  
L. ALVAREZ-RUSO ◽  
L. S. GENG ◽  
J. NIEVES ◽  
M. VALVERDE ◽  
...  
Keyword(s):  
Cross Section ◽  
Pion Production ◽  
Medium Energy ◽  
Medium Effects ◽  
Strong Reduction ◽  
Final State ◽  
Pion Wave Function ◽  
Final State Interactions ◽  
Nuclear Effects ◽  
Production Mechanisms

We discuss the relevance of nuclear medium effects in the analysis of some low and medium energy neutrino reactions of current interest. In particular, we study the Quasi-Elastic (QE) process, where RPA correlations and Final State Interactions (FSI) are shown to play a crucial role. We have also investigated the ν induced coherent pion production. We find a strong reduction of the cross section due to the distortion of the pion wave function and the modification of the production mechanisms in the nucleus. The sensitivity of the results to the axial NΔ coupling [Formula: see text] has been also investigated.

scholarly journals SEARCH FOR IN-MEDIUM MODIFICATIONS OF THE ρ MESON

2007 ◽  
Vol 22 (02n03) ◽  
pp. 380-387 ◽  
Author(s):  
◽  
D. P. WEYGAND ◽  
C. DJALALI ◽  
R. NASSERIPOUR ◽  
M. WOOD
Keyword(s):  
Spectral Function ◽  
Vector Mesons ◽  
Medium Effects ◽  
Final State ◽  
Collisional Broadening ◽  
Final State Interactions ◽  
Medium Modifications ◽  
Carbon Iron ◽  
Large Acceptance ◽  
Nuclear Effects

The photoproduction of vector mesons on various nuclei has been studied using the Cebaf Large Acceptance Spectrometer (CLAS) at Jefferson Laboratory, and here we present preliminary results. All three vector mesons, ρ, ω, and ϕ, are observed via their decay to e+e-, in order to reduce the effects of final state interactions in the nucleus. Of particular interest is possible in-medium effects on the properties of the ρ meson. The ρ spectral function is extracted from the data on various nuclei, carbon, iron, and titanium, and compared to the spectrum from liquid deuterium, which is relatively free of nuclear effects. We observe no effects on the mass of the ρ meson, however, there is some widening of the resonance in titanium and iron, which is consistent with expected collisional broadening.

scholarly journals EXTRACTION OF RESONANCE PARAMETERS AND ROLE OF THE FINAL STATE INTERACTIONS

2014 ◽  
Vol 26 ◽  
pp. 1460082 ◽  
Author(s):  
IGOR I. STRAKOVSKY ◽  
WILLIAM J. BRISCOE ◽  
ALEXANDER E. KUDRYAVTSEV ◽  
VLADIMIR E. TARASOV
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Impulse Approximation ◽  
Pion Photoproduction ◽  
Final State ◽  
The World ◽  
Final State Interactions ◽  
Watson’S Theorem ◽  
Photoproduction Data

We present an overview of the SAID group effort to analyze new γn → π-p cross sections vs. the world database to get new multipoles and determine neutron electromagnetic couplings. The differential cross section for the processes γn → π-p was extracted from new measurements at CLAS and MAMI-B accounting for Fermi motion effects in the impulse approximation (IA) as well as NN- and πN-FSI effects beyond the IA. We evaluated results of several pion photoproduction analyses and compared πN PWA results as a constraint for analyses of pion photoproduction data (Watson's theorem).

scholarly journals MESON2006 SUMMARY: THEORY

2007 ◽  
Vol 22 (02n03) ◽  
pp. 495-501
Author(s):  
TED BARNES
Keyword(s):  
B Mesons ◽  
Low Energy ◽  
Medium Effects ◽  
Final State ◽  
Hadron Physics ◽  
The Status ◽  
Recent Developments ◽  
Hadronic Production ◽  
Final State Interactions ◽  
Pion Nucleon

This is a summary of theoretical plenary contributions to the biennial hadron physics conference Meson2006, which was the ninth in this series. The topics covered in the meeting include low energy pion-pion and pion-nucleon interactions, photoproduction and hadronic production of light mesons and baryons, in-medium effects, recent developments in charmed mesons, charmonia and B mesons, the status of exotica, and some related topics such as final state interactions. In this contribution we review and summarize the plenary talks presented by theorists at the meeting, and emphasize some of the main points of their presentations. Where appropriate we will add brief comments on some aspects of QCD spectroscopy. Finally, following tradition, we conclude with a new Feynman story.

Electromagnetic breakup of the deuteron in the Δ resonance region

1984 ◽  
Vol 62 (11) ◽  
pp. 1036-1045 ◽  
Author(s):  
W. Leidemann ◽  
H. Arenhövel
Keyword(s):  
Cross Section ◽  
Degrees Of Freedom ◽  
Impulse Approximation ◽  
Resonance Region ◽  
Final State ◽  
Channel Calculation ◽  
Main Emphasis ◽  
Coupled Channel Calculation ◽  
Final State Interactions ◽  
Coupled Channel

The processes d(γ, p)n and d(e, e′p)n have been studied in the Δ resonance region with explicit Δ degrees of freedom in a coupled channel treatment that includes all final state interactions. In particular, the dependence on the model for the potential and the Δ parametrization has been investigated. The main emphasis has been put on the photodisintegration. The total cross section for this process is considerably reduced by inclusion of the Δ interactions, resulting in better agreement with a recent experiment. The angular distribution up to the resonance region shows a stronger forward and backward peaking than experimental results do, while above the resonance the agreement is better. Whereas the γ asymmetry is affected very little by the coupled channel calculation compared with the impulse approximation, the proton polarization is quite sensitive to the proper treatment of the Δ degrees of freedom.

scholarly journals Δ-Isobar contribution to the pion production in the reaction pp → {pp}sπ0

2019 ◽  
Vol 204 ◽  
pp. 01015
Author(s):  
Yuriy Uzikov
Keyword(s):  
Excitation Energy ◽  
Cross Section ◽  
Pion Production ◽  
Forward Direction ◽  
Dominant Contribution ◽  
Final State ◽  
Proton Pair ◽  
Order Of Magnitude ◽  
The Cross ◽  
The One

ANKE@COSY data on the cross section of the reaction pp → {pp}sπ0, where {pp}s is the proton pair in the 1S 0 state at small excitation energy Epp = 0 – 3 MeV, obtained at beam energies 0.5 - 2.0 GeV are analyzed within the one-pion exchange model. The model involves the subprocess π0 p → π0 p and accounts for the final state pp-interaction. A broad maximum observed in the cross section of the reaction pp → {pp}sπ0 at 0.5 - 1.4 GeV in the forward direction is explained by this model as a dominant contribution of the isospin $\cfrac{3}{2}$ in the π0 p-scattering. The second bump in data at 2 GeV is underpredicted within this model by one order of magnitude. An explicit excitation of the Δ(1232)-isobar using the box-diagram is also considered in the region of the first maximum.

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