Spectra In Pp Collisions Research Articles

Gluon saturation and leading particle spectra in pp collisions

electron-proton reactions at HERA with a c.m.s. energy one order of magnitude higher than in the other above mentioned hadronic experiments became available [9]. These measurements of LP spectra both in hadron-hadron and in electronproton collisions have renewed the interest on the subject, especially because the latter are measured at higher energies and therefore the energy dependence of the LP spectra can be determined.

Rapidity and centrality dependence in the percolating color strings scenario

In AA collisions fusion and percolation of color strings are studied at fixed rapidity y. Distribution of strings in rapidity is obtained from the observed rapidity spectra in pp collisions. For y-dependence of multiplicities in Au–Au collisions good agreement is obtained with the existing experimental data. Predictions for LHC energies coincide with the extrapolation of the data. Agreement with the data for the transverse momentum spectra requires introduction of quenching into the model.

Mid-Rapidity ϕ Meson Production at v( NN

We present the results for the measurement of ϕ meson production in \(\sqrt {s_{NN} } = 200\) GeV Au+Au and pp collisions at the Relativistic Heavy Ion Collider (RHIC). Using the event mixing technique, spectra and yields are obrained from the ϕ→K+K− decay channel for five centrality bins in Au+Au collisions and in pp collisions. We observe that the spectrum shape in Au+Au collisions depends weakly on the centrality and the shape of the spectrum in pp collisions is significantly different from that in Au+Au collisions.

ϕ meson production in Au + Au and pp collisions at RHIC

We present the results for the measurement of ϕ meson production in Au+Au and pp collisions at the relativistic heavy ion collider (RHIC). Using the event mixing technique, spectra and yields are obtained from the ϕ → K+K− decay channel for different centrality bins in Au+Au collisions and in pp collisions. We observe that the spectrum shape in Au+Au collisions depends weakly on the centrality, and the shape of the spectrum in pp collisions is significantly different from that in Au+Au collisions. In Au+Au collisions, the extracted yield of ϕ meson is flat as a function of rapidity; the ⟨pT⟩ of ϕ, extracted from the fit function to the spectra, shows a different behaviour as a function of centrality than that of π−, K− and .

Consequences of diffractive heavy flavor production

We calculate the lepton spectrum inpp collisions from the production and semileptonic decay ofΛc andΛb, and find limits on their production cross sections. Total cross sections in excess of 1 mb forΛc and 2 1/2μb forΛb violate the experimental fact that (μ/π)≲10−4. Abundant production ofΛc has led to speculations on the existence of a large intrinsic charm sea inside the proton. We discuss alternative ways of probing such a structure inside the proton: jets opposite highpT direct photons and central production of ψ.

Unified description of large and small pT spectra in pp collisions at PS and ISR energies

The inclusive spectra for pp → p, K ± and π ±X are analysed, separating the data into two components according to the flow of valence urbaryons. Each component is compared with the whole region formula composed of three factors, i.e. the normalization constant, an inverse power function in the transverse mass squared, and a scaling function of the radial and Feynman variables. A global agreement with the data is obtained concerning p T dependence connecting large and small p T, s dependence between PS and ISR and within ISR energies as well as the x dependence throughout the central and fragmentation regions up to the kinematical boundary. Difficulties are the pion distribution at very small p T and x, and the two-component separation of pions related to the counting violation.

A diffractive contribution to the single-particle inclusive neutron spectrum in pp collisions through low-mass resonance decay

The contribution of the two-step reaction, consisting in diffractive production of the N ∗(1470) resonance and its decay into a neutron, to the inclusive neutron spectrum in pp collisions, is studied in detail. It is found that, at low p⊥ and near x = 1, the effect gives rise to a peak which, in principle, can be detected in experiments with a good momentum resolution.

Comparison of an Inclusive Multiperipheral Model to Secondary Spectra inp−pCollisions

The quantitative predictions of an inclusive multiperipheral model are compared with the measured secondary spectra in pp collisions from 12 to 30 GeV/c.Received 5 April 1971DOI:https://doi.org/10.1103/PhysRevLett.27.353©1971 American Physical Society