Double Differential Yield Research Articles

Measurements of {Xi left( 1530right) ^{0}} and {overline{Xi }left( 1530right) ^{0}} production in proton\u2013proton interactions at sqrt{s_{NN}}\xa0=\xa017.3\xa0text{ GeV } in the NA61/SHINE\xa0experiment

Double-differential yields of {Xi left( 1530right) ^{0}} and {overline{Xi }left( 1530right) ^{0}} resonances produced in p+p interactions were measured at a laboratory beam momentum of 158 text{ GeV }!/!c. This measurement is the first of its kind in p+p interactions below LHC energies. It was performed at the CERN SPS by the NA61/SHINE collaboration. Double-differential distributions in rapidity and transverse momentum were obtained from a sample of 26times 10^6 inelastic events. The spectra are extrapolated to full phase space resulting in mean multiplicity of {Xi left( 1530right) ^{0}} (6.73 pm 0.25pm 0.67)times 10^{-4} and {overline{Xi }left( 1530right) ^{0}} (2.71 pm 0.18pm 0.18)times 10^{-4}. The rapidity and transverse momentum spectra and mean multiplicities were compared to predictions of string-hadronic and statistical model calculations.

Investigating heavy-flavor vs light-flavor puzzle with event topology and multiplicity in proton + proton collisions at = 13 TeV using PYTHIA8

Heavy-flavored hadrons are unique probes to study the properties of hot and dense quantum chromodynamics medium produced in ultra-relativistic heavy-ion collisions at RHIC and the LHC. Transverse spherocity is one of the event-topology variables used to separate jetty and isotropic events from the pool of event samples. This study aims to understand the production dynamics of heavy-flavors through the transverse momentum spectra, double differential yield and mean transverse momentum of J/ψ, D 0 and as a function of charged-particle multiplicity and transverse spherocity. Further to investigate the possibility of hadronization of the charm quarks, transverse spherocity dependence ratios like /D 0 and Λ0/K − are studied. For the current analysis, the events are generated by using 4C tuned PYTHIA8 for pp at = 13 TeV, which is quite successful in explaining the heavy-flavor particle production at the LHC energies.

Study of Hadrons Produced in Proton—Carbon Interactions at 120 GeV/c Using Hadron-Production Models

Double differential yield of π±, K±, protons, and antiprotons as a function of laboratory momentum is presented using hadron production models. This study is done in several polar angle intervals from 0 < θ < 420 mrad for π± mesons and 0 < θ < 360 mrad for K± mesons, protons, and antiprotons. The study is carried out for p + C interactions at 120 GeV/c. For simulation, three hadron-production models: EPOS-LHC, EPOS 1.99, and QGSJETII-04 are used. Since no experimental data at 120 GeV/c is available yet, therefore, the models’ predictions are compared with the measurements of NA61/SHINE experiments at 31 GeV/c. It is found that the QGSJETII-04 model gives high peak value, for π± mesons, in the polar angle interval of 20–40 mrad, while in the range of 40–240 mrad, EPOS-LHC shows higher yield than EPOS 1.99 and QGSJETII-04 models, whereas all show higher yield than the experimental data. For π± mesons, in all angular intervals, at high momentum values, all the three models are consistent and surprisingly give the same yield as that of the experimental data. For K± mesons, QGSJETII-04 shows higher peak values at all polar angles ranging from 0 to 360 mrad as compared to that of EPOS 1.99 and EPOS-LHC models, whereas all models give higher yield at low angular intervals than the experimental data and the same yield at high angular intervals. The models demonstrate similar yields for protons at all angles but underestimate the experimental data at low angular intervals and provide the same yield at high angular intervals. The QGSJETII-04 model presents higher yields of antiprotons in comparison to the EPOS 1.99 and EPOS-LHC models, for almost all angular intervals. Generally, at higher angular range, i.e., from 240 to 420 mrad, particularly at high momentum, all the three models show similar results.

Study of pion kaon and proton in proton–carbon interactions at 158 GeV/c using hadron production models

In this work, we investigate the production of [Formula: see text], [Formula: see text] mesons, protons and antiprotons, by exploiting the theoretical hadron production models: EPOS 1.99, EPOS-LHC and QGSJETII-04, using proton–carbon collisions at a potential laboratory momentum of 158 GeV/c. Laboratory momentum-dependent double differential yields of these particles are studied where it is produced at a polar angle ranging from 0 mrad to 420 mrad for [Formula: see text] mesons while for [Formula: see text] mesons, protons and antiprotons, the angle ranges from 0 mrad to 360 mrad. The QGSJET predicts high yields of the [Formula: see text] mesons for a polar angle ranging from 0 mrad to 20 mrad at the peak of the distribution while beyond 20 mrad, the high yield is demonstrated by EPOS-LHC. In the case of [Formula: see text] mesons and antiprotons, the QGSJETII-04 gives higher yield at the peak of the distribution in all the cases, whereas the EPOS-1.99 and EPOS-LHC produce similar results. In most of the cases at high momentum of the hadrons, the trios are in very good agreement with each other.

Measurements of pi ^pm , K^pm and proton double differential yields from the surface of the T2K replica target for incoming 31\xa0GeV/c protons with the NA61/SHINE spectrometer at the CERN SPS

Measurements of the pi ^pm , K^pm , and proton double differential yields emitted from the surface of the 90-hbox {cm}-long carbon target (T2K replica) were performed for the incoming 31,hbox {GeV}!/!c protons with the NA61/SHINE spectrometer at the CERN SPS using data collected during 2010 run. The double differential pi ^pm yields were measured with increased precision compared to the previously published NA61/SHINE results, while the K^pm and proton yields were obtained for the first time. A strategy for dealing with the dependence of the results on the incoming proton beam profile is proposed. The purpose of these measurements is to reduce significantly the (anti)neutrino flux uncertainty in the T2K long-baseline neutrino experiment by constraining the production of (anti)neutrino ancestors coming from the T2K target.

π±, K±, protons and antiprotons production in proton–carbon interactions at 31 GeV/c using hadron production models

Projects proposed for the long baseline neutrino and cosmic rays’ experiments require high precision hadron production measurements, using proton beam on different targets, to achieve their physics goals. The predictions of neutrino beam depend on the modeling of protons interacting within the targets. Thus, different hadronic models are being used for this purpose with different precisions, which depend on the projectile protons energy and material of the target used. The comparison of different hadron production models predictions, in proton–carbon interactions at 31 GeV/c, is reported in this paper. Double differential yield of [Formula: see text], [Formula: see text] mesons, protons and antiprotons in several polar angle ranges is presented as a function of laboratory momentum. EPOS1.99, EPOS-LHC and QGSJETII-04 models are used to perform simulations. The results of the simulated data are compared with hadron production measurements in proton–carbon interactions at 31 GeV/c performed by the NA61/SHINE experiment at the SPS CERN [Eur. Phys. J. C 76, 84 (2016)]. None of the models completely describes all the distributions. In most of the cases, EPOS1.99 describes the experimental data very well. EPOS-LHC results are also similar in some cases, but QGSJETII-04 predictions failed to reproduce the experimental data.

Comparison of different hadron production models for the study of π±, K±, protons and antiprotons production in proton–carbon interactions at 90 GeV/c

In this research paper, comprehensive results on the double differential yield of [Formula: see text] and [Formula: see text] mesons, protons and antiprotons as a function of laboratory momentum in several polar angle ranges from 0–420 mrad for pions, 0–360 mrad for kaons, proton and antiproton are reported. EPOS 1.99, EPOS-LHC and QGSJETII-04 models are used to perform simulations. The predictions of these models at 90 GeV/c are plotted for comparison, which shows that QGSJETII-04 model gives overall higher yield for [Formula: see text] mesons in the polar angle interval of 0–40 mrad but for the [Formula: see text] the yield is higher only up to 20 mrad. For [Formula: see text] mesons after 40 mrad, EPOS-LHC predicts higher yield as compared to EPOS 1.99 and QGSJETII-04 while EPOS-LHC and EPOS 1.99 give similar behavior in these two intervals. However, for [Formula: see text] mesons EPOS-LHC and EPOS 1.99 give similar behavior in these two intervals. For of [Formula: see text] mesons, QGSJETII-04 model gives higher predictions in all cases from 0–300 mrad, while EPOS 1.99 and EPOS-LHC show similar distributions. In case of protons, all models give similar distribution but this is not true for antiproton. All models are in good agreement for p [Formula: see text] 20 GeV/c. EPOS 1.99 produce lower yield compared to the other two models from 60–360 mrad polar angle interval.

Comparison of hadron production models for π±, k±, protons and antiprotons production in proton–carbon interactions at 60 GeV/c

In this research paper, the comprehensive results on the double differential yield of [Formula: see text] and [Formula: see text] mesons, protons and antiprotons as a function of laboratory momentum are reported. These hadrons are produced in proton–carbon interaction at 60 GeV/c. EPOS 1.99, EPOS-LHC and QGSJETII-04 models are used to perform simulations. Comparing the predictions of these models show that QGSJETII-04 model predicts higher yields of all the hadrons in most of the cases at the peak of the distribution. In this interval, the EPOS 1.99 and EPOS-LHC produce similar results. In most of the cases at higher momentum of the hadrons, all the three models are in good agreement. For protons, all models are in good agreement. EPOS-LHC gives high yield of antiprotons at high momentum values as compared to the other two models. EPOS-LHC gives higher prediction at the peak value for [Formula: see text] mesons and protons at higher polar angle intervals of [Formula: see text] and [Formula: see text], respectively, and EPOS 1.99 gives higher prediction at the peak value for [Formula: see text] mesons for [Formula: see text]. The model predictions, except for antiprotons, are compared with the data obtained by the NA61/SHINE experiment at 31 GeV/c proton–carbon collision, which clearly shows that the behavior of the distributions in models are similar to the ones from the data but the yield in data is low because of lower beam energy.

SU-GG-T-480: Neutron Production in Novel Heavy Ion Accelerators

Purpose: The use of heavy ions in radiation therapy represents a major step forward in terms of dose conformity and better tumorcontrol. Novel acceleration techniques involving high power lasers have the potential of reducing the footprint and cost of the accelerator and bring the whole system into the treatment vault. Therefore, knowledge of the amount of neutrons produced in the beam line and the patient is crucial. Method and Materials: Two Monte Carlo codes are used in this study: FLUKA2008 and Geant4. A collimated (2×2cm2) monoenergetic (450MeV/nucleon) carbon beam is incident on two types of targets: iron beam block (as a part of the particle selection system) and water phantom simulating patient being treated. The double differential yield (for energy and polar angle) is studied from FLUKA, while Geant4 is used for detailed studies of the angular distribution of neutrons.Results: Quantitative study of the spectral yield (neutrons/MeV/primary) reveals that neutrons with energies in excess of 50MeV are generated in abundance inside the patient with probability 2.5 times greater than that in beam modifiers. Lower energy and thermal neutrons originating from the beam blocks are found to have an order of magnitude higher yield than those generated inside the patient. We studied the angular distribution of energy density and found that a maximum of the distribution at ∼20° from the beam axis for iron beam modifiers and ∼10° for the patient phantom. This information is valuable for organdose calculation from secondary neutrons as well as beam‐line design. Conclusion:Monte Carlo simulations of neutron production in compact carbon accelerators are presented. Various parameters are studied that allow for accurate calculation of the organdose from secondary neutrons to be carried out. Shielding calculations for the vault and gantry can also be performed using the data from our study.

Neutron yield and dose equivalent from heavy ion interactions on thick target

Thick target neutron yields and angular distributions are essential for shielding calculations for ion beam accelerators. Most of such measurements available in the literature are for proton and alpha particle bombardments. In case of heavy ions, very few data are available in the energy region of 20 MeV amu −1 and below. We report here the neutron yield, double differential neutron yields and neutron dose equivalent values obtained from the double differential yields at 0° and 90° with respect to the beam for various heavy ions in the energy range of 3.5–7.0 MeV amu −1. Pulse shape discrimination was used to separate neutrons from gamma rays and time of flight technique was used for energy measurement. The double differential neutron yields were fitted using the moving source model and the nuclear temperature and source intensity are also determined. The neutron yield increases inversely with the mass of the projectile except in the case of 7Li where the yields are much lower than that obtained from 11B. This could be due to the structure of the loosely bound 7Li projectile. The neutron dose equivalent shows increasing trend with the decrease of the mass of the projectile.

Photoneutron Spectra from Thin Targets Bombarded with 2.0 GeV Electrons

Photoneutron spectra produced from thin targets bombarded with 2.04 GeV electrons were measured in the range from 9 MeV to 300 MeV by using the time of flight technique. The measurements were carried out for thin C, Al, Cu, Sn, and Pb targets at a fixed angle of 900 to the beam direction. In this data reduction a removal cross-section was newly calculated for compensating the effect of the Pb attenuator which was set to suppress γ-flash signal. The double differential yields per incident electron were obtained from the spectra as a function of the mass number of target elements. For neutron energies larger than 20 MeV the yields decreased with higher mass number of the target, which was consistent with other authors’ published results.

Electron emission from foils induced by heavy-ion collisions

Absolute double differential yield per ion has been calculated for forward and backward electron emission produced by collisions of highly charged uranium ions with carbon foil of varying thicknesses. A Monte Carlo method has been developed which employs multiple ionization of the carbon and subsequent energy and angular straggling of freed electrons through the foil. A comparison with experimental double differential electron emission yields shows general agreement. Calculated total electron emission is in agreement with experiment at 44 mu g cm-2 as well as the results of Rothard et al. (1990). In addition, the radial distribution of energy deposited by the electrons as they pass through the foil has been calculated. Comparison with the radial dose data of Toburen et al. (1989) shows qualitative agreement. The radial dose calculations were also performed for two different cases having the same stopping power (1 MeV/u U23+ and 21 MeV/u U67+) in order to test the supposition that the radial dose distribution is inversely related to the square of the radial distance (Kellerer, 1977).

Investigation of the impact-parameter dependence of electrons emitted in 30-, 100-, 350-keV H+ and 100-keV 3He

Energy distributions of electrons ejected in collisions of light ions with Ar atoms were measured as a function of projectile scattering angle. For this purpose the ion-electron coincidence technique was combined with the time-of-flight method for electron momentum analysis. Thus, the simultaneous detection of electrons with energies from a few hundred meV up to some keV and ions at different projectile scattering angles could be performed. The electron analyzer could observe electrons at ejection angles of 40/sup 0/--140/sup 0/ with respect to the beam axis. A time resolution of less than 400 ps was achieved with a recently developed position-sensitive ion detector. For the first time, absolute double differential yields for electron emission were measured as a function of impact parameter and electron energy for the system H/sup +/+Ar at collision energies of 30, 100, and 350 keV. Also L-shell ionization yields were determined for 30-, 100-, and 350-keV H/sup +/ and 100-keV He/sup 2+/ impact on Ar. The results are compared with predictions of the plane-wave Born approximation, an atomic orbital expansion, and the semiclassical approximation. Total L-shell ionization cross sections were deduced and compared to other measurements.