The differential cross sections for inclusive neutral pions as a function of transverse and longitudinal momentum in the very forward rapidity region have been measured at the Large Hadron Collider (LHC) with the Large Hadron Collider forward detector (LHCf) in proton-proton collisions at $\sqrt{s}=$ 2.76 and 7 TeV and in proton-lead collisions at nucleon-nucleon center-of-mass energies of $\sqrt{s_\text{NN}}=$ 5.02 TeV. Such differential cross sections in proton-proton collisions are compatible with the hypotheses of limiting fragmentation and Feynman scaling. Comparing proton-proton with proton-lead collisions, we find a sizable suppression of the production of neutral pions in the differential cross sections after subtraction of ultra-peripheral proton-lead collisions. This suppression corresponds to the nuclear modification factor value of about 0.1-0.3. The experimental measurements presented in this paper provide a benchmark for the hadronic interaction Monte Carlo simulation codes that are used for the simulation of cosmic ray air showers.
The average $\pi^{0}$ transverse momenta for the rapidity range $8.8<y<10.6$ in $p+p$ collisions at $\sqrt{s}=2.76$ and 7 TeV and for the rapidity range $-8.8>y_\rm{lab}>-10.6$ in $p+\rm{Pb}$ collisions at $\sqrt{s_\rm{NN}}=5.02$ TeV. The rapidity values for $p+\rm{Pb}$ collisions are in the detector reference frame and must be multiplied by -1.
Production rate for the $\pi^{0}$ production in the rapidity range $8.8 < y < 9.0$ in $p+p$ collisions and in the rapidity range $-8.8 > y_\rm{lab} > -9.0$ in $p+\rm{Pb}$ collisions.
Production rate for the $\pi^{0}$ production in the rapidity range $9.0 < y < 9.2$ in $p+p$ collisions and in the rapidity range $-9.0 > y_\rm{lab} > -9.2$ in $p+\rm{Pb}$ collisions.
The production of $J/\psi$ mesons in proton-proton collisions at $\sqrt{s}$= 7 tev is studied with the LHCb detector at the LHC. The differential cross-section for prompt $J/\psi$ production is measured as a function of the $J/\psi$ transverse momentum p_{\rm T}\ and rapidity $y$ in the fiducial region $p_{\rm T}\in[0;14]$ GeV/c and $y\in[2.0;4.5]$. The differential cross-section and fraction of \j psi\ from $b$-hadron decays are also measured in the same p_{\rm T}\ and $y$ range s. The analysis is based on a data sample corresponding to an integrated luminos ity of 5.2 pb$^{-1}$. The measured cross-sections integrated over the fiducial region are $10.52\pm 0. 04\pm 1.40^{+1.64}_{-2.20}\mu b$ for $\mathrm{prompt}~J/\psi$ production and $1.14 \pm 0. 01\pm 0.16 \mu b$ for $J/\psi$ from $b$-hadron decays, where the first uncertainty is statistical and the second systematic. The $\mathrm{prompt}~J/\psi$ production cross-section is obtained assuming no $J/\psi$ polarisation and the third error indicates the acceptance uncertainty due to this assumption.
Integrated cross section in the defined fiducial region for prompt J/PSIs and for those from b-hadron decay assuming no polarisation. The second systematic error in the prompt cross section is the uncertainty related to the assumption of no polarisation.
The derived cross section for b-hadron production obtained by extrapolation to the full polar angle range using the LHCB MC based on Pythia6.4 and EvtGen and a branching ratio to J/PSI of 1.16+-0.1 PCT.
Mean PT and RMS for prompt J/PSI production (assuming unpolarised).
We present a study of the production of K_s^0 and Lambda^0 in inelastic pbar-p collisions at sqrt(s)= 1800 and 630 GeV using data collected by the CDF experiment at the Fermilab Tevatron. Analyses of K_s^0 and Lambda^0 multiplicity and transverse momentum distributions, as well as of the dependencies of the average number and <p_T> of K_s^0 and Lambda^0 on charged particle multiplicity are reported. Systematic comparisons are performed for the full sample of inelastic collisions, and for the low and high momentum transfer subsamples, at the two energies. The p_T distributions extend above 8 GeV/c, showing a <p_T> higher than previous measurements. The dependence of the mean K_s^0(Lambda^0) p_T on the charged particle multiplicity for the three samples shows a behavior analogous to that of charged primary tracks.
K0S inclusive invariant PT distribution for HARD events at a centre of massenergy 1800 GeV.
K0S inclusive invariant PT distribution for MB events at a centre of mass energy 1800 GeV.
K0S inclusive invariant PT distribution for SOFT events at a centre of massenergy 1800 GeV.
J/psi production has been measured in proton-proton collisions at sqrt(s)= 200 GeV over a wide rapidity and transverse momentum range by the PHENIX experiment at RHIC. Distributions of the rapidity and transverse momentum, along with measurements of the mean transverse momentum and total production cross section are presented and compared to available theoretical calculations. The total J/psi cross section is 3.99 +/- 0.61(stat) +/- 0.58(sys) +/- 0.40(abs) micro barns. The mean transverse momentum is 1.80 +/- 0.23(stat) +/- 0.16(sys) GeV/c.
Measured J/PSI distribution in PT for the e+e- channel. The value of B, the branching fraction to either electrons or muons is the average value from PDG : 5.9%.The rapidity range is -0.35<y<0.35. Incertainties are 1-sigma statistical errors on the (signal - background) net yield. There is a 10% overall absolute cross section normalization error in addition to the error given.
Measured J/PSI distribution in PT for the mu+mu- channel. The value of B, the branching fraction to either electrons or muons, is the average value from PDG: 5.9%.The rapidity range is -2.2<y<-1.2. Incertainties are 1-sigma statistical errors on the (signal - background) net yield.There is a 10% overall absolute cross section normalization error in addition to the error given.
J/PSI distribution in rapidity. The data at rapidity = 0 is from the electron arm, the data from the muon arm, corresponding to forward rapidity is divided in two bins.The value of B,the branching fraction to either electrons or muons, is 5.9%, the average value from PDG.Incertainties are 1-sigma statistical errors on the (signal - background) net yield.There is a 10% overall absolute cross section normalization error in addition to the error given.
Identified pi^[+/-] K^[+/-], p and p-bar transverse momentum spectra at mid-rapidity in sqrt(s_NN)=130 GeV Au-Au collisions were measured by the PHENIX experiment at RHIC as a function of collision centrality. Average transverse momenta increase with the number of participating nucleons in a similar way for all particle species. The multiplicity densities scale faster than the number of participating nucleons. Kaon and nucleon yields per participant increase faster than the pion yields. In central collisions at high transverse momenta (p_T greater than 2 GeV/c), anti-proton and proton yields are comparable to the pion yields.
Transverse momentum spectra for PI+ in the midrapidity range for the centrality region 0 to 5 PCT. Errors are combined statistical and systematics.
Transverse momentum spectra for PI- in the midrapidity range for the centrality region 0 to 5 PCT. Errors are combined statistical and systematics.
Transverse momentum spectra for K+ in the midrapidity range for the centrality region 0 to 5 PCT. Errors are combined statistical and systematics.
We present a measurement of jet shapes in p¯p collisions at √s =1.8 TeV at the Fermilab Tevatron using the Collider Detector at Fermilab (CDF). Qualitative agreement is seen with the predictions of recent next-to-leading [O(αs3)] calculations and with leading logarithm QCD based Monte Carlo simulations. The dependence of the jet shape on transverse energy is studied.
No description provided.
Measurements of inclusive transverse-momentum spectra for KS0 mesons produced in proton-antiproton collisions at s of 630 and 1800 GeV are presented and compared with data taken at lower energies. The ratio, as a function of pT, of the cross section for KS0 to that for charged hadrons is very similar to what is observed at lower energies. At 1800 GeV, we calculate the strangeness-suppression factor λ=0.40±0.05.
Estimated effective cross sections for events which pass the trigger and selection criteria. The uncertainties in these represent the principal source of error in the overall normalisation of the results.
Statistical errors only.
Statistical errors only.
We present results on the jet structure observed in multihadronic events produced by e+e− annihilation in the Mark I magnetic detector at SPEAR. The evidence for jet structure and the jet-axis angular distribution are reported. We give inclusive distributions of the hadrons in Feynman x, rapidity, and transverse momentum relative to the jet axis.
Observed particle PT with respect to jet axis for events with three or more detected charged particles.
No description provided.
No description provided.
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