Flavour symmetry breaking in the kaon parton distribution amplitude
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72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
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The Structure of Excited 0{sup +} States in Nuclei and the Effect of the {gamma} Degree of Freedom
The physics of intrinsic states, within the pairing gap of deformed nuclei with N{approx}90 neutrons, is discussed in the light of the recent realization that the first excited 0{sub 2}{sup +} states in these nuclei are not {beta}-vibrations but four quasi-neutron states. The properties of {gamma}-vibration K{sup {pi}} = 2{sup +} bands is discussed. A method of measuring two proton transfer in high resolution using the ({sup 3}He,n) reaction is proposed.
73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
Recent results on nuclear structure functions for light nuclei
We discuss the nuclear EMC effect with particular emphasis on recent data for light nuclei including {sup 2}H, {sup 3}He, {sup 4}He, {sup 9}Be, {sup 12}C and {sup 14}N. In order to verify the consistency of available data, we calculate the {chi}{sup 2} deviation between different data sets. We find a good agreement between the results from the NMC, SLAC E139, and HERMES experiments. However, our analysis indicates an overall normalization offset of about 2% in the data from the recent JLab E03-103 experiment with respect to previous data for nuclei heavier than {sup 3}He. We also discuss the extraction of the neutron/proton structure function ratio F{sub 2}{sup n}/F{sub 2}{sup p} from the nuclear ratios {sup 3}He/{sup 2}H and {sup 2}H/{sup 1}H. Our analysis shows that the E03-103 data on {sup 3}He/{sup 2}H require a renormalization of about 3% in order to be consistent with the F{sub 2}{sup n}/F{sub 2}{sup p} ratio obtained from the NMC experiment. After such a renormalization, the {sup 3}He data from the E03-103 data and HERMES experiments are in a good agreement. We also present a detailed comparison between data and model calculations, which include a description of the nuclear binding, Fermi motion and off-shell corrections to the structure functions of bound proton and neutron, as well as the nuclear pion and shadowing corrections.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Light Cone Dynamics and EMC Effects in the Extraction of F{sub 2n} at Large Bjorken x
We discuss theoretical issues related to the extraction of deep inelastic (DIS) structure function of neutron from inclusive DIS scattering off the deuteron at large Bjorken x. Theoretical justification is given to the consideration of only pn component of the deuteron wave function and consistency with both the baryonic number and light-cone momentum conservation sum rules. Next we discuss the EMC type effects and argue that in all cases relevant to the nuclear DIS reactions at large x the main issue is the medium modification of the properties of bound nucleon rather than the non-nucleonic components like pions. We give brief description of the color screening model of EMC and within this model we estimate uncertainties in the extraction of the neutron DIS structure function at large x. We emphasize also that these uncertainties are rather ''model independent'' since any theoretical framework accounting for the medium modification is proportional to the magnitude of the virtuality of bound nucleon which increases with an increase of x.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
The Partonic Structure of the Pion at Large-x
Unlike the proton, whose parton distributions have been extracted using abundant data, the pion has been relatively ignored. The pion, nevertheless, is a crucial part of the current understanding of the nucleon's parton distributions and of the binding of the nucleon into a nucleus. The pion's structure becomes more intriguing when its dual roles as a light quark-antiquark system and as QCD's Goldstone boson are considered. One source of data on the pion's structure is pion-induced Drell-Yan scattering. Two recent re-analyses of such data are discussed here.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Quark-hadron duality in structure functions
We review recent progress in the study of quark-hadron duality in electron-nucleon structure functions. New developments include insights into the local aspects of duality obtained using truncated moments of structure functions, which allow duality-violating higher-twist contributions to be identified in individual resonance regions. Preliminary studies of pion electropro-duction have also showed the first glimpses of duality in semi-inclusive cross sections, which if confirmed would greatly expand the scope of constraining the flavor and spin dependence of parton distributions.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Skyrmions - Construction and Applications
Skyrmions are topologically stabilised solutions in a field theory of pions, and are used to model protons, neutrons and larger nuclei. They have been constructed by a combination of numerical methods and geometrical insight. Ideas to extend the range of known solutions are discussed.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Analyses of {pi}{sup {+-}-40}Ca Elastic Scattering Data in the Delta Resonance Region using Inverse Scattering Theory and the Klein-Gordon Equation
The elastic scattering cross sections for {pi}{sup +} by {sup 40}Ca have been analyzed, for the first time, using the Klein-Gordon (KG) equation that incorporates the Coulomb interaction between the charged pions and targets explicitly for the incident energies of 163.3 and 180 MeV. The nuclear part of the potentials is determined using an inverse scattering theory as a guide. Our results are then compared to those where the Coulomb potential has not been explicitly included in the KG equation but its effect is studied by modifying the incident kinetic energy following the prescription of Stricker. Our calculations that include the Coulomb potential in the KG equation reproduce the results using the Stricker prescription for {pi}{sup +}. The Stricker method is then used to calculate {pi}{sup -} scattering. In all cases, the data have been well accounted for.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Coherent {pi}{sup 0}-photoproduction on the deuteron including polarization observables
Coherent {pi}{sup 0}-photoproduction on the deuteron including polarization effects in the energy region from {pi}-threshold up to 1 GeV is studied using an enhanced elementary pion photo-production operator on the free nucleon and a realistic NN potential model for the deuteron wave function. Results for double polarization observables are predicted for which the sensitivity to various models for the elementary pion photoproduction amplitude is investigated. We find considerable dependence of the results on the elementary amplitude. In addition, results for differential cross section are predicted and compared with the experimental data from TAPS and a satisfactory agreement was found.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Status of NOvA
NOvA is a long-baseline neutrino oscillation experiment looking for the appearance of electron neutrinos and antineutrinos in the NuMI neutrino beam. It is comprised of a near detector located on-site at Fermilab, approximately 1 km from the neutrino source and a far detector located 810 km from the source in northern Minnesota. Both detectors are positioned 14 mrad off the beam axis to observe a narrow range of neutrino energies peaked at 2.2 GeV. Construction of the NOvA experiment has begun and the details are outlined below.
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
New determination of the N-{Delta}(1232) axial form factors from weak pion production and coherent pion production off nuclei at T2K and MiniBooNE energies revisited
We re-evaluate our model predictions in Phys. Rev. D 79, 013002 (2009) for different observables in neutrino induced coherent pion production. This comes as a result of the new improved fit to old bubble chamber data of the dominant axial C{sub 5}{sup A} nucleon-to-Delta form factor. We find an increase of 20%{approx}30% in the values for the total cross sections. Uncertainties induced by the errors in the determination of C{sub 5}{sup A} are computed. Our new results turn out to be compatible within about 1{sigma} with the former ones. We also stress the existing tension between the recent experimental determination of the {sigma}(CCcoh{pi}{sup +})/{sigma}(NCcoh{pi}{sup 0}) ratio by the SciBooNE Collaboration and the theoretical predictions.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
GiBUU and Neutrino-Nucleus scattering
The Giessen BUU transport approach applied to electroweak interactions on nuclei in the few-GeV region is presented. After describing the model ingredients (elementary cross sections, medium effects and final state interactions), the impact of nuclear effects on the observables is discussed. We emphasize the interconnection of quasielastic and pion production processes, which receive a unified treatment, and its relevance for present neutrino experiments.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Kaon Production Off the Nucleon
We have studied the weak kaon production off the nucleon induced by neutrinos at the low and intermediate energies. The studied mechanisms are the main source of kaon production for neutrino energies up to 1.2 to 1.5 GeV for the various channels and the cross sections are large enough to be amenable to be measured by experiments such as MINERvA and T2K.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Measurement of charged pion cross section in proton carbon interaction at 30 GeV with the NA61/SHINE apparatus
Among other goals, the NA61/SHINE (SHINE {identical_to} SPS Heavy Ion and Neutrino Experiment) detector at CERN SPS aims at precision hadro-production measurements to characterise the neutrino beam of the T2K experiment at J-PARC. These measurements are performed using a 30 GeV proton beam produced at the SPS with a thin carbon target and a full T2K replica target. Preliminary spectra of {pi}{sup -} and {pi}{sup +} inclusive inelastic cross section were obtained from pilot data collected in 2007 with a 2 cm thick target (4% of the interaction length). After a description of the SHINE detector and its particle identification capabilities, results from three different analysis are presented.
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
Pion Production for Neutrino Factory-challenges
One of the key issues in the design of a Neutrino Factory target station is the determination of the optimum kinetic energy of the proton beam due to the large uncertainties in simulations of protons impinging on nuclear targets. In this paper we have developed a procedure to correct GEANT4 simulations for the HARP data, and we have determined the yield of muons expected at the front-end of a Neutrino Factory as a function of target material (Be, C, Al, Ta and Pb) and energy (3-12 GeV).The maximum muon yield is found between 5 and 8 GeV for high Z targets and 3 GeV for low Z targets.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Muon density enhancement with a tapered capillary method
The focusing effect of a muon beam with a tapered capillary method has been investigated in a range from 4.2 MeV to 9.2 MeV (i.e. from 30 MeV/c to 45 MeV/c in momentum). We injected the muon beam into a pair of narrowing (tapered) plates and tubes made of glass, copper and gold-coated copper, and measured the energy distribution of the muon leaving from the outlet. The plates were tilted from an inlet of 40 mm to an outlet of 20 mm. The density enhancement was more prominent with the plates made of heavier elements. The largest beam density enhancement at 10 mm downstream of the outlet was 1.3 with the gold-coated copper narrowing plates. The enhancement was composed of muons scattered with a small angle. Their energy was slightly less than that of the initial beam. This effect did not depend on the surface roughness. The result strongly suggests a simple and effective way to increase the muon beam density for a small target.
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
Main Injector Particle Production Experiment (MIPP) at Fermilab
The Main Injector Particle Production Experiment at Fermilab uses particle beams of charged pions, kaons, proton and anti-proton with beam momenta of 5 to 90 GeV/c and thin targets spanning the periodic table from (liquid) hydrogen to uranium to measure particle production cross sections in a full acceptance spectrometer with charged particle identification for particles from 0.1 to 120 GeV/c using Time Projection Chamber, Time of Flight, multicell Cherenkov, and Ring Imaging Cherenkov detectors and Calorimeter for neutrons. Particle production using 120 GeV/c protons from Main Injector on the MINOS target was also measured. We describe the physics motivation to perform such cross section measurements and highlight the impact of hadronic interaction data on neutrino physics. Recent results on forward neutron cross sections and analysis of MINOS target data are also presented.
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
Lepton event rates in neutrino-nucleus DIS
In this work we have studied the nuclear effect in F{sub 2}{sup A}(x) and F{sub 3}{sup A}(x) weak structure functions and calculated {nu}-nucleus cross section using them by taking into account Fermi motion, binding energy, pion and rho meson cloud contributions and shadowing and anti-shadowing effects. The numerical calculations have been performed in a local density approximation using relativistic nuclear spectral functions which include nucleon correlations for nuclear matter. The results have been compared with the experimental results of NuTeV and CDHSW collaborations.
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