Hadron generation in the Geant4 simulation tool kit is compared with inclusive spectra of secondary protons and pions from the interactions with beryllium nuclei of +8.9 GeV/c protons and pions, and of -8.0 GeV/c pions. The data were taken in 2002 at the CERN Proton Synchrotron with the HARP spectrometer. We report on significant disagreements between data and simulated data especially in the polar-angle distributions of secondary protons and pions.
We report on double-differential inclusive cross-sections of the production of secondary protons and charged pions, in the interactions with a 5% interaction length thick stationary beryllium target, of proton and pion beams with momentum from +/-3 GeV/c to +/-15 GeV/c. Results are given for secondary particles with production angles between 20 and 125 degrees.
We report on double-differential inclusive cross-sections of the production of secondary protons, deuterons, and charged pions and kaons, in the interactions with a 5% nuclear interaction length thick stationary beryllium target, of a +8.9 GeV/c proton and pion beam, and a -8.0 GeV/c pion beam. Results are given for secondary particles with production angles between 20 and 125 degrees.
The double-differential production cross-section of positive pions, $d^2σ^{π^{+}}/dpdΩ$, measured in the HARP experiment is presented. The incident particles are 8.9 GeV/c protons directed onto a beryllium target with a nominal thickness of 5% of a nuclear interaction length. The measured cross-section has a direct impact on the prediction of neutrino fluxes for the MiniBooNE and SciBooNE experiments at Fermilab. After cuts, 13 million protons on target produced about 96,000 reconstructed secondary tracks which were used in this analysis. Cross-section results are presented in the kinematic ra…
Measurements of the double-differential $π^{\pm}$ production cross-section in the range of momentum $100 \MeVc \leq p < 800 \MeVc$ and angle $0.35 \rad \leq θ< 2.15 \rad$ in proton--beryllium, proton--aluminium and proton--lead collisions are presented. The data were taken with the HARP detector in the T9 beam line of the CERN PS. The pions were produced by proton beams in a momentum range from 3 \GeVc to 12.9 \GeVc hitting a target with a thickness of 5% of a nuclear interaction length. The tracking and identification of the produced particles was performed using a small-radius cylindrical ti…
Hadron generation models are indispensable for the simulation and calibration of particle physics detectors. The models used by the Geant4 simulation tool kit are compared with inclusive spectra of secondary protons and pions from the interactions with beryllium nuclei of +8.9 GeV/c protons and pions, and of -8.0 GeV/c pions. We report on significant disagreements between data and model predictions especially in the polar-angle distributions of secondary protons and pions.
We report on double-differential inclusive cross-sections of the production of secondary protons, charged pions, and deuterons, in the interactions with a 5% nuclear interaction length thick stationary lead target, of proton and pion beams with momentum from +/-3 GeV/c to +/-15 GeV/c. Results are given for secondary particles with production angles 20 to 125 degrees. Cross-sections on lead nuclei are compared with cross-sections on beryllium, copper, and tantalum nuclei.
Measurements of the double-differential charged pion production cross-section in the range of momentum 100 MeV/c < p < 800 MeV/c and angle 0.35 < θ< 2.15 rad in proton-beryllium, proton-carbon, proton-aluminium, proton-copper, proton-tin, proton-tantalum and proton-lead collisions are presented. The data were taken with the large acceptance HARP detector in the T9 beam line of the CERN PS. The pions were produced by proton beams in a momentum range from 3 GeV/c to 12.9 GeV/c hitting a target with a thickness of 5% of a nuclear interaction length.
We report on double-differential inclusive cross-sections of the production of secondary protons, charged pions, and deuterons, in the interactions with a 5% nuclear interaction length thick stationary tin target, of proton and pion beams with momentum from \pm3 GeV/c to \pm15 GeV/c. Results are given for secondary particles with production angles between 20 and 125 degrees. Cross-sections on tin nuclei are compared with cross-sections on beryllium, carbon, copper, tantalum and lead nuclei.
We report on double-differential inclusive cross-sections of the production of secondary protons, charged pions, and deuterons, in the interactions with a 5% λint thick stationary aluminium target, of proton and pion beams with momentum from \pm3 GeV/c to \pm15 GeV/c. Results are given for secondary particles with production angles between 20 and 125 degrees. Cross-sections on aluminium nuclei are compared with cross-sections on beryllium, carbon, copper, tin, tantalum and lead nuclei.
We report on double-differential inclusive cross-sections of the production of secondary protons, charged pions, and deuterons, in the interactions with a 5% nuclear interaction length thick stationary carbon target, of proton and pion beams with momentum from \pm 3 GeV/c to \pm 15 GeV/c. Results are given for secondary particles with production angles between 20 and 125 degrees. Cross-sections on carbon nuclei are compared with cross-sections on beryllium, copper, tantalum and lead nuclei.
Total cross sections for Sigma- and pi- on beryllium, carbon, polyethylene and copper as well as total cross sections for protons on beryllium and carbon have been measured in a broad momentum range around 600GeV/c. These measurements were performed with a transmission technique adapted to the SELEX hyperon-beam experiment at Fermilab. We report on results obtained for hadron-nucleus cross sections and on results for sigma_tot(Sigma- N) and sigma_tot(pi- N), which were deduced from nuclear cross sections.
Rapidity-dependent transverse momentum spectra of negatively charged pions measured at different rapidities in proton-proton collisions at the Super Proton Synchrotron (SPS) at various energies within its Beam Energy Scan (BES) program are investigated by using one- and two-component standard distributions where the chemical potential and spin property of particles are implemented. The rapidity spectra are described by a double-Gaussian distribution. At the stage of kinetic freeze-out, the event patterns are structured by the scatter plots in the three-dimensional subspaces of velocity, moment…
We report on the comparison of production characteristics of secondary protons and charged pions in the interactions of protons and charged pions with momentum between 3 GeV/c and 15 GeV/c with beryllium, copper, and tantalum nuclei, with simulations by the FLUKA and Geant4 Monte Carlo tool kits. Overall production cross-sections are reasonably well reproduced, within factors of two. In more detail, there are areas with poor agreement that are unsatisfactory and call for modelling improvements. Overall, the current FLUKA simulation fares better than the current Geant4 simulation.
Precise measurements of neutrino oscillation parameters and of neutrino-nucleon cross-sections require a good understanding of neutrino beams: flux as a function of energy, transverse beam profile, and flavour composition. For this, hadron production spectra in proton-nucleus collisions are essential. We report on double-differential inclusive large-angle cross-sections of the production of secondary protons and charged pions, in the interactions with a 5% lambda thick stationary beryllium target, of proton and pion beams with momentum from 3 GeV/c to 15 GeV/c. Our results show cross-sections …
The PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) has measured the single-spin transverse asymmetry ($A_{N}$) for neutral pion and non-identified charged hadron production at $x_{F}\sim 0$ over a transverse momentum range of $\sim$ 0.5 to 5.0 GeV/c from polarized proton-proton interactions at a center of mass energy ($\sqrt{s}$) of 200 GeV. The asymmetries observed are consistent with zero.
Measurements of the double-differential proton production cross-section in the range of momentum 0.5 GeV/c < p < 8.0 GeV/c and angle 0.05 rad < θ< 0.25 rad in collisions of charged pions and protons on beryllium, carbon, aluminium, copper, tin, tantalum and lead are presented. The data were taken with the large acceptance HARP detector in the T9 beam line of the CERN Proton Synchrotron. Incident particles were identified by an elaborate system of beam detectors and impinged on a target of 5 % of a nuclear interaction length. The tracking and identification of the produced particles was perform…
We report on double-differential inclusive cross-sections of the production of secondary protons, charged pions, and deuterons, in the interactions with a 5% nuclear interaction length thick stationary copper target, of proton and pion beams with momentum from +/-3 GeV/c to +/-15 GeV/c. Results are given for secondary particles with production angles between 20 and 125 degrees.
Measurements of the double-differential charged pion production cross-section in the range of momentum 0.5 GeV/c < p < 8.0 GeV/c and angle 0.025 rad < theta <0.25 rad in collisions of protons on beryllium, carbon, nitrogen, oxygen, aluminium, copper, tin, tantalum and lead are presented. The data were taken with the large acceptance HARP detector in the T9 beam line of the CERN PS. Incident particles were identified by an elaborate system of beam detectors. The data were taken with thin targets of 5% of a nuclear interaction length. The tracking and identification of the produced particles was…
The mean transverse momenta of hadrons, <P_{\bot}>, produced in e^+ N deep inelastic scattering was studied as a function of the hadron energy fraction z and the Bjorken variable x. The statistical accuracy of the HERMES data permitted to observe at high z differences in <P_{\bot}> between hadrons with positive and negative charges, h^+, h^- and K_s^0 for the first time. These differences can presumably be explained by the flavour dependence of the intrinsic transverse momentum distributions of quarks in the initial nucleon.
We report on double-differential inclusive cross-sections of the production of secondary protons, charged pions, and deuterons, in the interactions with a 5% nuclear interaction length thick stationary tantalum target, of proton and pion beams with momentum from +/-3 GeV/c to +/-15 GeV/c. Results are given for secondary particles with production angles between 20 and 125 degrees. They are of particular relevance for the optimization of the design parameters of the proton driver of a neutrino factory.
The transverse single-spin asymmetries of neutral pions and non-identified charged hadrons have been measured at mid-rapidity in polarized proton-proton collisions at sqrt(s) = 200 GeV. The data cover a transverse momentum (p_T) range 0.5-5.0 GeV/c for charged hadrons and 1.0-5.0 GeV/c for neutral pions, at a Feynman-x (x_F) value of approximately zero. The asymmetries seen in this previously unexplored kinematic region are consistent with zero within statistical errors of a few percent. In addition, the inclusive charged hadron cross section at mid-rapidity from 0.5 < p_T < 7.0 GeV/c is prese…
We present data from Fermilab experiment E781 (SELEX) on the hadroproduction asymmetry for anti-Lambda_c compared to Lambda_c+ as a function of xF and pt2 distributions for Lambda_c+. These data were measured in the same apparatus using incident pi-, sigma- beams at 600 GeV/c and proton beam at 540 GeV/c. The asymmetry is studied as a function of xF. In the forward hemisphere with xF >= 0.2 both baryon beams exhibit very strong preference for producing charm baryons rather than charm antibaryons, while the pion beam asymmetry is much smaller. In this energy regime the results show that beam fr…
The STAR experiment at RHIC has measured a variety of inclusive hadron cross sections in $p+p$ collisions at Sqrt(s) = 200 GeV. Measurements of the differential cross section for inclusive charged pion production at mid rapidity and for inclusive neutral pion production at forward rapidity (3.0 < eta < 4.2) as well as the first preliminary result from STAR for the differential cross section for inclusive neutral pion production near mid rapidity are presented. These cross sections are compared to next-to-leading order perturbative QCD calculations and can provide constraints on the pion fragme…
Inclusive production cross sections of $π^\pm$, $K^\pm$ and $p\bar{p}$ per hadronic $e^+e^-$ annihilation event in $e^+e^-$ are measured at a center-of-mass energy of 10.54 GeV, using a relatively small sample of very high quality data from the BaBar experiment at the PEP-II $B$-factory at the SLAC National Accelerator Laboratory. The drift chamber and Cherenkov detector provide clean samples of identified $π^\pm$, $K^\pm$ and $p\bar{p}$ over a wide range of momenta. Since the center-of-mass energy is below the threshold to produce a $B\bar{B}$ pair, with $B$ a bottom-quark meson, these data r…
We report on the response of a prototype CMS hadron calorimeter module to charged particle beams of pions, muons, and electrons with momenta up to 375 GeV/c. The data were taken at the H2 and H4 beamlines at CERN in 1995 and 1996. The prototype sampling calorimeter used copper absorber plates and scintillator tiles with wavelength shifting fibers for readout. The effects of a magnetic field of up to 3 Tesla on the response of the calorimeter to muons, electrons, and pions are presented, and the effects of an upstream lead tungstate crystal electromagnetic calorimeter on the linearity and energ…
In this paper a new comprehensive analysis of parton-to-pion fragmentation functions (FFs) is performed for the first time by including all experimental data sets on single inclusive pion as well as unidentified light charged hadron production in electron-positron ($e^+e^-$) annihilation. We determine the pion FFs along with their uncertainties using the standard "Hessian" technique at next-to-leading order (NLO) and next-to-next-to leading order (NNLO) in perturabative QCD. It is shown that the determination of pion FFs using simultaneously the data sets from pion and unidentified light charg…
The pion structure is represented by Generelazed parton distribution functions (GPDs). The momentum transfer dependence of GPDs of the pion was obtained on the basis of the form of GPDs of the nucleon in the framework of the high energy generalized structure (HEGS) model. To this end, different forms of PDFs of the pion of various Collaborations were examined with taking into account the available experimental data on the pion form factors. As a result, the electromagnetic and gravitomagnetic form factors of the pion were calculated. They were used in the framework of the HEGS model with the e…
Semi-inclusive processes are very promising to investigate $XYZ$ hadrons at the next generation of electron-hadron facilities, because they generally boast higher cross sections. We extend our formalism of exclusive photoproduction to semi-inclusive final states. The inclusive production cross sections for charged axial-vector $Z$ states from pion exchange are predicted. We isolate the contribution of $Δ$ resonances at small missing mass. Production near threshold is shown to be enhanced roughly by a factor of two compared to the exclusive reaction. We benchmark the model with data of semi-inc…
In this paper, the first femtoscopic analysis of pion-kaon correlations at the LHC is reported. The analysis was performed on the Pb-Pb collision data at $\sqrt{s_{\rm{NN}}}$ = 2.76 TeV recorded with the ALICE detector. The non-identical particle correlations probe the spatio-temporal separation between sources of different particle species as well as the average source size of the emitting system. The sizes of the pion and kaon sources increase with centrality, and pions are emitted closer to the centre of the system and/or later than kaons. This is naturally expected in a system with strong …
NA61/SHINE is a fixed target experiment designed to study hadron-proton, hadron-nucleus and nucleus-nucleus interactions at the CERN Super-Proton-Synchrotron. In this proceeding we present results on spectra of identified hadrons produced in pion-carbon production interactions, which are of fundamental importance to improve the extensive air shower modeling, and hence the interpretation of ultra-high-energy-cosmic-rays measurements. In particular, our measurements of (anti)baryons and $ρ^0$ production in pion-carbon interactions can contribute to improve the predictions of muon production by a…
The pseudoscalar-vector-vector correlator is constructed using two meson multiplets in the vector and two in the pseudoscalar channel. The parameters are constrained by the operator product expansion at leading order where two or all three momenta are considered as large. Demanding in addition the Brodsky-Lepage limit one obtains (in the chiral limit) a pion-vector-vector correlator with only one free parameter. The singly virtual pion transition form factor and the decay width of omega to pion and photon are independent of this parameter and can serve as cross-checks of the results. The free …
We explore the relationship between exclusive and inclusive electromagnetic scattering from the pion, focusing on the transition region at intermediate Q^2. Combining Drell-Yan data on the leading twist quark distribution in the pion with a model for the resonance region at large x, we calculate QCD moments of the pion structure function over a range of Q^2, and quantify the role of higher twist corrections. Using a parameterization of the pion elastic form factor and phenomenological models for the pi -> rho transition form factor, we further test the extent to which local duality may be vali…
Data are recalled on the relative yields of charged pions,charged kaons,protons,antiprotons,tritiun nuclei, anti-tritium, He3 nuclei and anti-He3 antinuclei produced at 0 degrees by 200-240 GeV/c protons on Beryllium and Aluminium targets. A search for the production of long-lived particles with charges 2/3, 1, 4/3, is described; for negative particle production the upper limits obtained at the 95% Confidence Level were at the level of 10-11 with respect to the production of known particles.
The CALICE collaboration investigates different technology options for highly granular calorimeters for detectors at a future electron-positron collider. One of the devices constructed and tested by the collaboration is a 1m^3 prototype for an imaging scintillator-steel sampling calorimeter for hadrons with analogue readout (AHCAL). The light from 7608 small scintillator cells is detected with silicon photomultipliers. The AHCAL has been successfully operated during electron and hadron test-beam measurements at DESY, CERN, and Fermilab since 2005. The collected data allow for evaluating the no…
The possibility of formation of Bose-Einstein Condensation (BEC) is studied in $pp$ collisions at $\sqrt s$ = 7 TeV at the Large Hadron Collider. A thermodynamically consistent non-extensive formulation of the identified hadron transverse momentum distributions is used to estimate the critical temperature required to form BEC of charged pions, which are the most abundant species in a multi-particle production process in hadronic and nuclear collisions. The obtained results have been contrasted with the systems produced in Pb-Pb collisions to have a better understanding. We observe an explicit …
Atomic nuclei can be used as spatial analyzers of the hadronization process in semi-inclusive deep inelastic scattering. The study of this process using fully-identified final state hadrons began with the HERMES program in the late 1990s, and is now continuing at Jefferson Lab. In the measurement described here, electrons and positive pions were measured from a 5 GeV electron beam incident on targets of liquid deuterium, C, Fe, and Pb using CLAS in Hall B. The broadening of the transverse momentum of positive pions has been studied in detail as a function of multiple kinematic variables, and i…
Working with proton and pion valence distribution functions (DFs) determined consistently at the same, unique hadron scale and exploiting the possibility that there is an effective charge which defines an evolution scheme for DFs that is all-orders exact, we obtain a unified body of predictions for all proton and pion DFs - valence, glue, and four-flavour-separated sea. Whilst the hadron light-front momentum fractions carried by identifiable parton classes are the same for the proton and pion at any scale, the pointwise behaviour of the DFs is strongly hadron-dependent. All calculated distribu…
Experimental results of the rapidity distributions of negatively charged pions produced in proton-proton ($p$-$p$) and beryllium-beryllium (Be-Be) collisions at different beam momentums, measured by the NA61/SHINE Collaboration at the super proton synchrotron (SPS), are described by a revised (three-source) Landau hydrodynamic model. The squared speed-of-sound parameter $c^2_s$ is then extracted from the width of rapidity distribution. There is a local minimum (knee point) which indicates a softest point in the equation of state (EoS) appearing at about 40$A$ GeV/$c$ (or 8.8 GeV) in $c^2_s$ ex…
Generalized parton distributions (GPDs) are three-dimensional structure functions of hadrons, and they can reveal the orbital-angular-momentum contributions to the nucleon spin. Therefore, GPDs are important for solving the proton spin puzzle. The generalized distribution amplitudes (GDAs) are the $s$-$t$ crossed quantities of the GPDs, and the GDAs can be investigated in two-photon process ($γ^* γ\to h\bar h$) which is accessible at KEKB. The pion GDAs were obtained by analyzing the Belle measurements for $π^0 π^0$ production in the $e^+ e^-$ collision. From the obtained GDAs, the form factor…
The study of pion production in nuclei is important for signal and background determinations in current and future neutrino oscillation experiments. The first step, however, is to understand the pion production reactions at the free nucleon level. We present an exhaustive study of the charged-current and neutral-current neutrino and antineutrino pion production off nucleons, paying a special attention to the angular distributions of the outgoing pion. We show, using general arguments, that parity violation and time-reversal odd correlations in the weak differential cross sections are generated…
Hadron tomography can be investigated by three-dimensional structure functions such as generalized parton distributions (GPDs), transverse-momentum-dependent parton distributions, and generalized distribution amplitudes (GDAs). Here, we extract the GDAs, which are $s$-$t$ crossed quantities of the GPDs, from cross-section measurements of hadron-pair production process $γ^* γ\rightarrow π^0 π^0$ at KEKB. This work is the first attempt to obtain the GDAs from the actual experimental data. The GDAs are expressed by a number of parameters and they are determined from the data of $γ^* γ\rightarrow …
Hadron tomography has been investigated by three-dimensional structure functions, such as generalized parton distributions (GPDs) and generalized distribution amplitudes (GDAs). The GDAs are $s$-$t$ crossed quantities of the GPDs, and both functions probe gravitational form factors for hadrons. We determined the pion GDAs by analyzing Belle data on the differential cross section for the two-photon process $γ^* γ\to π^0 π^0$. From the determined GDAs, we calculated timelike gravitational form factors of the pion and they were converted to the spacelike form factors by using the dispersion relat…
