Measurement Of Production Cross Section Research Articles

Measurement of 43Sc and 44Sc production cross-section with an 18 MeV medical PET cyclotron

43Sc and 44Sc are positron emitter radionuclides that, in conjunction with the β− emitter 47Sc, represent one of the most promising possibilities for theranostics in nuclear medicine. Their availability in suitable quantity and quality for medical applications is an open issue and their production with medical cyclotrons represents a scientific and technological challenge. For this purpose, an accurate knowledge of the production cross sections is mandatory. In this paper, we report on the cross section measurement of the reactions 43Ca(p,n)43Sc, 44Ca(p,2n) 43Sc, 46Ti(p,α)43Sc, and 44Ca(p,n)44Sc at the Bern University Hospital cyclotron. A study of the production yield and purity performed by using commercially available enriched target materials is also presented.

Jet-parton assignment in tt̄H events using deep learning

The direct measurement of the top quark-Higgs coupling is one of the important questions in understanding the Higgs boson. The coupling can be obtained through measurement of the top quark pair-associated Higgs boson production cross-section. Of the multiple challenges arising in this cross-section measurement, we investigate the reconstruction of the partons originating from the hard scattering process using the measured jets in simulated tt̄H events. The task corresponds to an assignment challenge of m objects (jets) to n other objects (partons), where m≥ n. We compare several methods with emphasis on a concept based on deep learning techniques which yields the best results with more than 50% of correct jet-parton assignments.

Measurement of the cross section of the residues from the B11 -induced reaction on Y89 and Nb93 : Production of Ru97 and Rh101m

The heavy-ion induced reactions on intermediate mass targets are complex in nature, even at the low energies. To understand those nuclear reaction phenomena in detail, more experimental studies are required in a wide range of energy. Heavy-ion reactions were investigated by measuring production cross sections of the residues produced in the $^{11}$B-induced reactions on $^{89}$Y and $^{93}$Nb at low energies, near and above the barrier, and to check the effectiveness of the different nuclear models to explain them. Further, aim is also to optimize the production parameters of neutron deficient medically relevant $^{97}$Ru and $^{101m}$Rh radioisotopes produced in those reactions, respectively. The $^{11}$B-beam was allowed to impinge on $^{89}$Y and $^{93}$Nb foils supported by an aluminum catcher foil, arranged in a stack, in 27.5-58.7 and 30.6-62.3 MeV energy range, respectively. The $\gamma$-spectrometry was carried out after EOB to measure the activity of the radionuclides produced in each foil and cross sections were calculated. Measured cross-sectional data were analyzed in terms of compound and precompound model calculations. The measured cross sections of the residues showed good agreement with the model calculations based on the Hauser-Feshbach formulation and exciton model. A substantial preequilibrium contribution was noticed in the 3$n$ reaction channel in both the reactions. Theoretical estimations confirmed that major production yields are mostly contributed by the compound reaction process. Preequilibrium emissions contributed at the high energy tail of the 3$n$ channel for both the reactions. Moreover, an indirect signature of a direct reaction influence was also observed in the $^{90m}$Y production.

Cross section measurements for production of positron emitters for PET imaging in carbon therapy

In light ion beam therapy, positron (β+) emitters are produced by the tissue nuclei through nuclear interactions with the beam ions. They can be used for the verification of the delivered dose using positron emission tomography by comparing the spatial distribution of the β+ emitters activity to a computer simulation taking into account the patient morphology and the treatment plan. However, the accuracy of the simulation greatly depends on the method used to generate the nuclear interactions producing these emitters. In the case of Monte Carlo (MC) simulations, the nuclear interaction models still lack the required accuracy due to insufficient experimental cross section data. This is particularly true for carbon therapy where literature data on fragmentation cross sections of a carbon beam with targets of medical interest are very scarce. Therefore, we performed at GANIL in July 2016 measurements on β+ emitter production cross sections with a carbon beam at 25, 50, and 95 MeV/nucleon on thin targets (C, N, O, and PMMA). We extracted the production cross section of C10,11, N13, and O14,15 that are essential to constrain or develop MC nuclear fragmentation models.

Measurements of the line resolved M-shell X-ray production cross sections for 79Au, 82Pb and 83Bi by 100 keV/u proton, C, N, O ions

The cross sections for production of the Mk (k=ξ, αβ, γ, m1) X-rays of 79Au, 82Pb and 83Bi induced by the 100keV/u proton, C4+, N5+ and O6+ ions have been measured in the present work. The experimental cross sections have been compared with the earlier reported values and those calculated using the ionization cross sections based on the ECPSSR model, the X-ray emission rates based on the Dirac-Fock model, the fluorescence and Coster-Kronig yields based on the Dirac-Hartree-Slater model. In addition, the present measured proton induced X-ray production cross sections have also been compared with those calculated using the Dirac-Hartree-Slater model based ionization cross sections. The intensity ratios among the Mk X-rays have been deduced and compared with the theoretical values. The present measured Mk (k=ξ, αβ, γ, m1) X-ray production cross sections are found to be very high as compared to the theoretical values. The total M X-ray production cross sections for the targets under investigation exhibited Zp2 dependence; Zp denotes the projectile atomic number.

Measurements of differential production cross sections for a Z boson in association with jets in pp collisions at sqrt{s}=8 TeV

Cross sections for the production of a Z boson in association with jets in proton-proton collisions at a centre-of-mass energy of sqrt{s}=8 TeV are measured using a data sample collected by the CMS experiment at the LHC corresponding to 19.6 fb−1. Differential cross sections are presented as functions of up to three observables that describe the jet kinematics and the jet activity. Correlations between the azimuthal directions and the rapidities of the jets and the Z boson are studied in detail. The predictions of a number of multileg generators with leading or next-to-leading order accuracy are compared with the measurements. The comparison shows the importance of including multi-parton contributions in the matrix elements and the improvement in the predictions when next-to-leading order terms are included.

Measurement of jet production cross sections in deep-inelastic ep scattering at HERA

A precision measurement of jet cross sections in neutral current deep-inelastic scattering for photon virtualities 5.5<Q^2 <80,mathrm {GeV}^2 and inelasticities 0.2<y<0.6 is presented, using data taken with the H1 detector at HERA, corresponding to an integrated luminosity of 290,mathrm {pb}^{-1}. Double-differential inclusive jet, dijet and trijet cross sections are measured simultaneously and are presented as a function of jet transverse momentum observables and as a function of Q^2. Jet cross sections normalised to the inclusive neutral current DIS cross section in the respective Q^2-interval are also determined. Previous results of inclusive jet cross sections in the range 150<Q^2 <15{,}000,mathrm {GeV}^2 are extended to low transverse jet momenta 5<P_mathrm{T}^mathrm{jet} <7,mathrm {GeV} . The data are compared to predictions from perturbative QCD in next-to-leading order in the strong coupling, in approximate next-to-next-to-leading order and in full next-to-next-to-leading order. Using also the recently published H1 jet data at high values of Q^2, the strong coupling constant alpha _s(M_Z) is determined in next-to-leading order.

Leptonic mono-top from single stop production at the LHC

Top squark (stop) can be produced via QCD interaction but also the electroweak interaction at the LHC. In this paper, we investigate the observability of the associated production of stop and chargino, ppto {tilde{t}}_1{tilde{chi}}_{overline{1}} , in compressed electroweakino scenarios at 14 TeV LHC. Due to small mass splitting between the lightest neutralino ( {tilde{chi}}_1^0 ) and chargino ( {tilde{chi}}_1^{-} ), the single stop production can give the mono-top signature through the stop decay {tilde{t}}_1to t{tilde{chi}}_1^0 . We analyze the leptonic mono-top channel of the single stop production and propose a lab-frame observable cos θbℓ to reduce the SM backgrounds. We find that such leptonic mono-top events from the single stop production can be probed at 2σ level at the HL-LHC if {m}_{{tilde{t}}_1}<760 GeV and {m}_{{tilde{chi}}_1^0}<150 GeV. Given a discovery of the stop and a measurement of the single stop production cross section, the stop mixing angle can also be determined from the single stop production at the HL-LHC.

Measurement of gamma-ray production cross sections in Li and F induced by protons from 810 to 3700 keV

Differential cross sections for the reaction channels 7Li(p,nγ1-0)7Be (Eγ=429keV), 7Li(p,pγ1-0) (Eγ=478keV), 19F(p,pγ1-0)19F (Eγ=110keV), 19F(p,pγ2-0)19F (Eγ=197keV) have been measured in the proton energy range 810–3700keV, with an energy step of 10keV. The reactions channels 19F(p,pγ3-1)19F (Eγ=1236keV), 19F(p,pγ4-1)19F (Eγ=1349keV), 19F(p,pγ5-2)19F (Eγ=1357keV) have also been investigated in the proton energy range 1915–3225keV. The experimental set-up, the uncertainty budget, the comparison with other data and the progress assured by new data in the analytical use of standard-less Particle Induced Gamma-ray Emission (PIGE) are discussed.

Measurement of the b-Quark Production Cross Section in 7 and 13TeV pp Collisions.

Measurements of the cross section for producing b quarks in the reaction pp→bb[over ¯]X are reported in 7 and 13TeV collisions at the LHC as a function of the pseudorapidity η in the range 2<η<5 covered by the acceptance of the LHCb experiment. The measurements are done using semileptonic decays of b-flavored hadrons decaying into a ground-state charmed hadron in association with a muon. The cross sections in the covered η range are 72.0±0.3±6.8 and 154.3±1.5±14.3 μb for 7 and 13TeV. The ratio is 2.14±0.02±0.13, where the quoted uncertainties are statistical and systematic, respectively. The agreement with theoretical expectation is good at 7TeV, but differs somewhat at 13TeV. The measured ratio of cross sections is larger at lower η than the model prediction.

First measurement of the muon neutrino charged current single pion production cross section on water with the T2K near detector

The T2K off-axis near detector, ND280, is used to make the first differential cross section measurements of muon neutrino charged current single positive pion production on a water target at energies ${\sim}0.8$ GeV. The differential measurements are presented as a function of muon and pion kinematics, in the restricted phase-space defined by $p_{\pi^+}>200$MeV/c, $p_{\mu^-}>200$MeV/c, $\cos \theta_{\pi^+}>0.3$ and $\cos \theta_{\mu^-}>0.3$. The total flux integrated $\nu_\mu$ charged current single positive pion production cross section on water in the restricted phase-space is measured to be $\langle\sigma\rangle_\phi=4.25\pm0.48 (\mathrm{stat})\pm1.56 (\mathrm{syst})\times10^{-40} \mathrm{cm}^{2}/\mathrm{nucleon}$. The total cross section is consistent with the NEUT prediction ($5.03\times10^{-40} \mathrm{cm}^{2}/\mathrm{nucleon}$) and 2$\sigma$ lower than the GENIE prediction ($7.68\times10^{-40} \mathrm{cm}^{2}/\mathrm{nucleon}$). The differential cross sections are in good agreement with the NEUT generator. The GENIE simulation reproduces well the shapes of the distributions, but over-estimates the overall cross section normalization.

Implementation of the n-body Monte-Carlo event generator into the Geant4 toolkit for photonuclear studies

A data-based Monte Carlo simulation algorithm, Geant4-GENBOD, was developed by coupling the n-body Monte-Carlo event generator to the Geant4 toolkit, aiming at accurate simulations of specific photonuclear reactions for diverse photonuclear physics studies. Good comparisons of Geant4-GENBOD calculations with reported measurements of photo-neutron production cross-sections and yields, and with reported energy spectra of the 6Li(n,α)t reaction were performed. Good agreements between the calculations and experimental data were found and the validation of the developed program was verified consequently. Furthermore, simulations for the 92Mo(γ,p) reaction of astrophysics relevance and photo-neutron production of 99Mo/99mTc and 225Ra/225Ac radioisotopes were investigated, which demonstrate the applicability of this program. We conclude that the Geant4-GENBOD is a reliable tool for study of the emerging experiment programs at high-intensity γ-beam laboratories, such as the Extreme Light Infrastructure – Nuclear Physics facility and the High Intensity Gamma-Ray Source at Duke University.

Measurement of the ZZ production cross section in proton-proton collisions at sqrt{s}=8 TeV using the ZZ \u2192 \u2113\u2212\u2113+\u2113\u2032\u2212\u2113\u2032+ and ZZto {ell}^{-}{ell}^{+}nu overline{nu} decay channels with the ATLAS detector

A measurement of the ZZ production cross section in the ℓ−ℓ+ℓ′ −ℓ′ + and {ell}^{-}{ell}^{+}nu overline{nu} channels (ℓ = e, μ) in proton-proton collisions at sqrt{s}=8 TeV at the Large Hadron Collider at CERN, using data corresponding to an integrated luminosity of 20.3 fb−1 collected by the ATLAS experiment in 2012 is presented. The fiducial cross sections for ZZ → ℓ−ℓ+ℓ′ −ℓ′ + and ZZto {ell}^{-}{ell}^{+}nu overline{nu} are measured in selected phase-space regions. The total cross section for ZZ events produced with both Z bosons in the mass range 66 to 116 GeV is measured from the combination of the two channels to be 7.3 ± 0.4(stat) ± 0.3(syst)− 0.1− 0.2(lumi) pb, which is consistent with the Standard Model prediction of 6. 6− 0.6+ 0.7 pb. The differential cross sections in bins of various kinematic variables are presented. The differential event yield as a function of the transverse momentum of the leading Z boson is used to set limits on anomalous neutral triple gauge boson couplings in ZZ production.

Measurement of aluminum activation cross section and gas production cross section for 0.4 and 3-GeV protons

To estimate the lifetime and the radiation dose of the proton beam window used in the spallation neutron source at J-PARC, it is necessary to understand the accuracy of the production cross section of 3-GeV protons. To obtain data on aluminum, the reaction cross section of aluminum was measured at the entrance of the beam dump placed in the 3-GeV proton synchrotron. Owing to the use of well-calibrated current transformers and a well-collimated beam, the present data has good accuracy. After irradiation, the cross sections of Al(p,x)7 Be, Al(p,x)22 Na-22 and Al(p,x)24 Na were obtained by gamma-ray spectroscopy using a Ge detector. It was found that the evaluated data of JENDL/HE-2007 agree well with the current experimental data, whereas intra-nuclear cascade models (Bertini, INCL-4.6, and JAM) with the GEM statistical decay model underestimate by about 30% in general. Moreover, gas production, such as T and He, and the cross sections were measured for carbon, which was utilized as the muon production target in J-PARC. The experiment was performed with 3-GeV proton having beam power of 0.5 MW, and the gasses emitted in the process were observed using a quadrupole mass spectrometer in the vacuum line for beam transport to the mercury target. It was found that the JENDL/HE-2007 data agree well with the present experimental data.

Measurements of the mathrm{t}overline{mathrm{t}} production cross section in lepton+jets final states in pp collisions at 8 ,text {TeV} and ratio of 8 to 7\xa0,text {TeV} cross sections

A measurement of the top quark pair production (mathrm{t}overline{mathrm{t}} ) cross section in proton–proton collisions at the centre-of-mass energy of 8,text {TeV} is presented using data collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 19.6,text {fb}^{-text {1}}. This analysis is performed in the mathrm{t}overline{mathrm{t}} decay channels with one isolated, high transverse momentum electron or muon and at least four jets, at least one of which is required to be identified as originating from hadronization of a b quark. The calibration of the jet energy scale and the efficiency of b jet identification are determined from data. The measured mathrm{t}overline{mathrm{t}} cross section is 228.5 pm 3.8,text {(stat)} pm 13.7,text {(syst)} pm 6.0,text {(lumi)} text { pb} . This measurement is compared with an analysis of 7,text {TeV} data, corresponding to an integrated luminosity of 5.0,text {fb}^{-text {1}}, to determine the ratio of 8,text {TeV} to 7,text {TeV} cross sections, which is found to be 1.43 pm 0.04,text {(stat)} pm 0.07,text {(syst)} pm 0.05,text {(lumi)} . The measurements are in agreement with QCD predictions up to next-to-next-to-leading order.

Top physics at the LHC ?

The status of top physics at the Large Hadron Collider is discussed, with particular attention on measurements of top production cross sections, including associate production of top quarks and electroweak bosons, and on measurements of the top mass.

Cross sections for nuclide production in proton- and deuteron-induced reactions on 93Nb measured using the inverse kinematics method

Isotopic production cross sections were measured for proton- and deuteron-induced reactions on 93 Nb by means of the inverse kinematics method at RIKEN Radioactive Isotope Beam Factory. The measured production cross sections of residual nuclei in the reaction 93 Nb + p at 113 MeV/u were compared with previous data measured by the conventional activation method in the proton energy range between 46 and 249 MeV. The present inverse kinematics data of four reaction products (90 Mo, 90 Nb, 88 Y, and 86 Y) were in good agreement with the data of activation measurement. Also, the model calculations with PHITS describing the intra-nuclear cascade and evaporation processes generally well reproduced the measured isotopic production cross sections.

Top quark production measurements using the ATLAS detector at the LHC

A selection from the inclusive top-quark pair production and single top-quark production cross-section measurements in proton-proton collisions with the ATLAS detector at the Large Hadron Collider is presented, with data collected in 2012 and early 2015 at centre-of-mass energies of 8 TeV and 13 TeV, respectively.

Measurements of X-ray production cross sections at photon energies across the Li (i = 1–3) sub-shell absorption edges of 74W and 76Os using synchrotron radiation

The cross sections for production of the Lk (k=l, η, α, β1,3,4,6, β2,15,5,7, γ1,5, γ2,3) X-rays have been measured at different incident photon energies ranging 10.2–13.1keV across the Li (i=1–3) sub-shell absorption edge energies of 74W and 76Os. These measured XRP cross sections, σLk(exp), exhibited significant differences with two sets of the theoretical values calculated using the Dirac–Fock (DF) model based X-ray emission rates provided by Campbell and Wang (1989), Dirac–Hartree–Slater (DHS) model based fluorescence (ωi) and Coster–Kronig (fij) yields given by Puri et al. (1993) and two sets of the Li (i=1–3) sub-shell photoionization cross sections based on the non-relativistic Hartree–Fock–Slater (HFS) model tabulated by Scofield (1973) and those deduced from the self-consistent Dirac–Hartree–Fock (DHF) model based theoretical total photoionization attenuation coefficients tabulated by Chantler (1995). However, the branching ratios (ILk/ILα)exp (k=l, β2,15) and(ILk/ILβ1)exp (k=γ1,5, η) are found to agree with the theoretical values.

Systematic measurement of double-differential neutron production cross sections for deuteron-induced reactions at an incident energy of 102 MeV

Double-differential neutron production cross sections (DDXs) for deuteron-induced reactions on Li, Be, C, Al, Cu, and Nb at 102MeV were measured at forward angles ≤25° by means of a time of flight (TOF) method with NE213 liquid organic scintillators at the Research Center of Nuclear Physics (RCNP), Osaka University. The experimental DDXs and energy-integrated cross sections were compared with TENDL-2015 data and Particle and Heavy Ion Transport code System (PHITS) calculation using a combination of the KUROTAMA model, the Liege Intra-Nuclear Cascade model, and the generalized evaporation model. The PHITS calculation showed better agreement with the experimental results than TENDL-2015 for all target nuclei, although the shape of the broad peak around 50MeV was not satisfactorily reproduced by the PHITS calculation.