We report on a study of inclusive particle production in pp-interactions at 400 GeV/c. The data are based on 472 K reconstructed events recorded in the NA 27 experiment using the LEBC-EHS facility at CERN. The production cross sections are determined of pseudo scalar (π±,0, η andK±), scalar (f0(975)), vector (ρ±,0(770), ω(783), ϕ(1020),K*0(892), and\(\bar K^{ * 0} \)(892)), and tensorf0 mesons, of protons and antiprotons, and theΔ++,+,0(1232), and Λ(1520) baryon resonances in the forward hemisphere of the center of mass system, as well as longitudinal and transverse momentum distributions. The results are compared with predictions of the FRITIOF model and with other experimental data.
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The cross sections for π ± , K ± , p, and p production in pp collisions have been measured at transverse momenta from 0.48 up to 2.21 GeV/ c at 70 GeV. The data are compared with results obtained at lower and higher proton energies and also with the quantum chromodynamics parton model (QPM) calculations. Common behaviour of the cross sections of the form g(p ⊥ )⨍(x ⊥ ) in the energy range above 200 GeV does not take place at lower energies. Qualitatively QPM fits the data and the best agreement is for π + / π − and K + / π + ratios.
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Transverse momentum distributions and yields for $\pi^{\pm}$, $K^{\pm}$, $p$ and $\bar{p}$ in $p+p$ collisions at $\sqrt{s}$=200 and 62.4 GeV at midrapidity are measured by the PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC). These data provide important baseline spectra for comparisons with identified particle spectra in heavy ion collisions at RHIC. We present the inverse slope parameter $T_{\rm inv}$, mean transverse momentum $<p_T>$ and yield per unit rapidity $dN/dy$ at each energy, and compare them to other measurements at different $\sqrt{s}$ in $p+p$ and $p+\bar{p}$ collisions. We also present the scaling properties such as $m_T$ scaling, $x_T$ scaling on the $p_T$ spectra between different energies. To discuss the mechanism of the particle production in $p+p$ collisions, the measured spectra are compared to next-to-leading-order or next-to-leading-logarithmic perturbative quantum chromodynamics calculations.
Invariant cross sections for inclusive PI+ and PI- production in P P collisions at a centre-of-mass energy of 200 GeV. There is an additional normalization uncertainty of 9.7 PCT.
Invariant cross sections for inclusive K+ and K- production in P P collisions at a centre-of-mass energy of 200 GeV. There is an additional normalization uncertainty of 9.7 PCT.
Invariant cross sections for inclusive P and PBAR production in P P collisions at a centre-of-mass energy of 200 GeV with feed-down weak decay corrections NOT applied. There is an additional normalization uncertainty of 9.7 PCT.
The ratio of the yields of antiprotons to protons in pp collisions has been measured by the ALICE experiment at $\sqrt{s} = 0.9$ and $7$ TeV during the initial running periods of the Large Hadron Collider(LHC). The measurement covers the transverse momentum interval $0.45 < p_{\rm{t}} < 1.05$ GeV/$c$ and rapidity $|y| < 0.5$. The ratio is measured to be $R_{|y| < 0.5} = 0.957 \pm 0.006 (stat.) \pm 0.014 (syst.)$ at $0.9$ TeV and $R_{|y| < 0.5} = 0.991 \pm 0.005 (stat.) \pm 0.014 (syst.)$ at $7$ TeV and it is independent of both rapidity and transverse momentum. The results are consistent with the conventional model of baryon-number transport and set stringent limits on any additional contributions to baryon-number transfer over very large rapidity intervals in pp collisions.
The PT dependence of the pbar/p ratio for the central rapidity region ABS(YRAP)<0.5.
The central rapidity pbar/p ratio as a function of the rapidity interval Ybeam-Ybaryon and centre-of-mass energy. As well as the present ALICE measurements this table also lists the values from other experiments (see the text of the paper for details).
The transverse momentum distribution at 90° of pions, protons and antiprotons have been measured at the CERN intersecting storage rings for C.M. energies between 23.2 and 52.7 GeV. In this energy range, the pion and proton distributions are almost energy independent. The antiproton production rises by a factor of two between 23.2 and 52.7 GeV.
The invariant cross section was fitted by CONST*EXP(-SLOPE*PT).
The invariant cross section was fitted by CONST*EXP(-SLOPE(C=1)*PT+SLOPE(C=2)*PT**2).
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We present measurements of the invariant cross section for the inclusive reaction p+p→p+X in the region 0.14<|t|<0.38 GeV2, 100<s<750 GeV2, and 0.80<x<0.93.
The cross sections are fitted by the formula CONST(C=A)*EXP(SLOPE*T)*(1+CO NST(C=B)/SQRT(S)).
We present an analysis, in the framework of the triple Regge model, of our recent experimental results on the reaction p+p→p+X between 50 and 400 GeV.
The cross sections is fitted in the framework of the triple Regge model. The symbols P and R in the (C=...) denote pomeron and reggeon, respectively. For fit I and II the authors used conventional trajectories alpha(P) = 1 +0.25*T, alpha(R) = 0.5 + T. Fit II is restricted to data with (1 - M(P=4)**2/S) > 0.84. In fit III they use alpha(R) = 0.2 + T for the RRP term. Fit IV is like fit I with additional fixed (pion pion P) term.
The cross sections is fitted in the farmework of the triple Regge model. The symbols P and R in teh (C=...) denote pomeron and reggeon, respectively. CONST(C=C) and SLOPE are from the replacement of the RRP term by the exponential one : CONST(C=C)*(SLOPE*(1-x)). See text for detail.
The inelastic reaction p+p→p+X is studied at 205 GeV/c. The distribution of the square of the missing mass, M2, shows a large diffractivelike peak at low M2 due to two-, four-, and six-prong events. The slope of the invariant cross section versus t decreases with increasing M2. The energy dependences of the multiplicity moments for the recoiling system X are similar to those for corresponding moments for p+p→(n chargedparticles).
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Data on stable hadron production in p + p and p + n interactions at 200 GeV/ c are reviewed. Methods to construct missing data in the p + p, p + n, and n + n interactions are derived from charge symmetry and charge, baryon and strangeness conservation, and used to yield nucleon-nucleon interaction results. These may be useful for evaluating nucleus-nucleus collision measurements in terms of enhancements and suppressions. Parameterizations of p t 2 and rapidity distributions are presented to provide yields in acceptance cuts for comparisons to nucleus-nucleus data. As an example the derived nucleon-nucleon multiplicities are reduced to the acceptances of the NA-35 CERN S + S experiment.
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Results of high-transverse-momentum charged-hadron production in 400-GeV/c proton-proton and proton-deuteron collisions and 800-GeV/c proton-proton collisions are presented. The transverse-momentum range of the data is from 5.2 to 9.0 GeV/c for the 400-GeV/c collisions and from 3.6 to 11.0 GeV/c for the 800-GeV/c collisions; the data are centered around 90° in the proton-nucleon center-of-momentum system. Single-pion invariant cross sections and particle ratios were measured at both energies. The results are compared to previous experiments and the Lund model.
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Events are analyzed in which a high transverse momentum proton was produced at polar angles of 10°, 20° and 45°. The experiment was performed with the Split Field Magnet detector at the CERN ISR at\(\sqrt s \)=62 GeV. A 4-jet structure of these events is found [1]. The measured charge structure of spectator jets is compatible with proton production from hard diquark scattering. This is supported by a study of baryon number compensation in the towards jets. The observed charge compensation in the towards jets suggests dominance of hard (ud) scattering. Evidence forΔ++ production at high transverse momentum indicates the presence of an additional (uu) scattering component. The properties of the recoiling away jets are compatible with the fragmentation of a valence quark and/or of a gluon as in the case of meson triggers.
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Data are presented on the reaction pp → pX in the range of four-momentum transfer squared 0.04< − t <0.80 GeV 2 and of c.m. energy squared 550 < s < 3880 GeV 2 . Invariant cross sections are given as a function of M 2 / s , where M is the mass of the missing system X, and of t . The cross sections are shown to scale in the variable M 2 / s , for M 2 / s > 0.01. The total diffractive cross section integrated over t and M 2 / s up to M 2 / s =0.05 rises by approximately 15% from σ dif =6.5±0.2 mb at 550 GeV 2 to σ dif =7.5±0.3 mb at 3880 GeV 2 .
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The polarization of the recoil proton has been measured in both high-energy elastic and inclusive proton-proton scattering at the internal-target area of Fermi National Accelerator Laboratory. The polarization in elastic scattering was measured at a number of center-of-mass energies up to s=19.7 GeV. Indications of negative polarization were seen at the higher center-of-mass energies for t values of -0.6, -0.8, and -1.0 (GeV/c)2. In the inclusive process p+p→p↑+X the polarization was found to be independent of beam energy from 100 to 400 GeV for xF values of -0.7, -0.8, -0.9. The polarization at PT=1.0 GeV/c, xF=−0.7 and xF=−0.8 was less than 2.5%. This is significantly lower than the corresponding measurements reported for Λ0 inclusive polarization.
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An experiment using the Fermilab Single Arm Spectrometer (SAS) facility and an associated nonmagnetic vertex detector studied the reactions a+p→c+X, where a and c were π±, K±, p, or p¯. Extensive measurements were made at 100 and 175 GeV/c beam momenta with the outgoing hadrons detected in the SAS covering a kinematic range 0.12<x<1.0 and pT<1.25 GeV/c. Additional data covering a more restricted range in x were also gathered at 70 GeV/c incident momentum. In this high-statistics experiment, the identification of both the incoming and outgoing charged hadrons were made with a total of eight Čerenkov counters. New and extensive single-particle inclusive data for charged-particle production in low-pT hadronic fragmentation are presented. The average associated charged-particle multiplicity and pseudorapidity distributions are also given.
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The properties of the diffractive peak observed in the mass spectra of systems recoiling against observed high-momentum protons emerging from pp collisions at the CERN ISR have been investigated. The cross sections in this peak have been found to have a steep t dependence which flattens out as | t | increases. The high mass side of the peak varies approximately as 1/ M 2 (where M is the missing mass of the recoiling system) and scales well in terms of the variable M 2 / s . The position of the maximum has been observed to move to lower values of M 2 / s as the kinematic boundary of this variable decreases with increasing s . The measured cross sections, integrated up to M 2 / s =0.05, rise by (15±5)% over the s range 549 to 1464 GeV 2 .
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A charge hyperon beam has been brought into operation at the CERN SPS. Particles are identified by a DISC Čerenkov counter, and decay products are analysed by a magnetic spectrometer. Cross sections for the inclusive production of π + , K + , p , Σ + , Σ − , ζ − , d, and π − , K − , p , Σ + , Σ − , ζ − , ω − , d in the forward direction have been measured at laboratory momenta between 70 and 130 GeV/ c . This range of momenta corresponds to 0.35 ⩽ x ⩽ 0.66 for an incident proton momentum of 200 GeV/ c . Antihyperon ( Σ − , ζ − , Σ + ) and Σ + and ω − fluxes have been measured for the first time in a hyperon beam.
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Measurements of the double differential cross sections for ππ and pπ production in pp collisions at the CERN ISR are presented for 5 c.m. energies s = 22, 30, 44, 53, 62 GeV . Charge and transverse momentum correlations are also reported.
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The inclusive production of low-momentum charged pions, kaons, and protons has been measured at x = 0 over the ISR energy range 23 < √ s < 63 GeV. The average increase in the invariant differential cross section is 36 ± 2% for π + , 41 ± 2% for π − , 52 ± 8% for K + , 69 ± 8% for K − , 8 ± 5% for p, and 84 ± for p ̄ . Pions have been measured in the range 0.04 < p T < 0.4 GeV/ c , kaons over 0.1 < p T < 0.3 GeV/ c , and nucleons over 0.1 < p T < 0.5 GeV/ c .
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Results are given on the inclusive production of charged pions, kaons, and nucleons, in proton-proton collisions at c.m. energies from √ s = 23 to 63 GeV at large angles and for the transverse momentum range 0.1 < p T < 4.8 GeV/ c . The dependence of the production spectra on the collision energy √ s , the transverse momentum p T , and the longitudinal rapidity is discussed.
Axis error includes +- 15.0/15.0 contribution (NORMALIZATION ERROR - THE LARGEST SYSTEMATICS).
Axis error includes +- 15.0/15.0 contribution (NORMALIZATION ERROR - THE LARGEST SYSTEMATICS).
Axis error includes +- 15.0/15.0 contribution (NORMALIZATION ERROR - THE LARGEST SYSTEMATICS).
We have measured the single-particle inclusive cross sections for p+p→π±+X, K±+X, p+X, p¯+X in the low-p⊥ region (≲ 1.5 GeV/c) as a function of the radial scaling variable XR in p−p collisions at 100, 200, and 400 GeV at Fermilab. The measured π+π− and K+K− ratios are shown to be remarkably similar to the same ratios which have recently been measured at large p⊥ at 90° in the center-of-mass system.
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The results of an experiment conducted at Fermilab to measure the polarization of the final-state proton in the reaction p+p→p↑+X and p+C→p↑+X are presented. Measurements were made at beam energies of 100, 200, 300, and 400 GeV for PT from 0.5 to 1.5 GeV/c and xF between - 0.7 and - 0.9.
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We report results from a measurement of the inclusive processes pp→Xp and pd→Xd in the range 5<Mx2s<0.1, 0.01≲|t|≲0.1 (GeV/c)2, and incident proton momenta of 65, 154, and 372 GeV/c. Both pp and pd data show an exponential t dependence and a dominant 1Mx2 behavior for Mx2s≲0.05. By comparing pp and pd data we test factorization and, using the Glauber model, we measure the XN total cross section, σXN=43±10 mb.
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We report differential cross sections for h+p→X+p (h=π±,K±,p±) at 100 and 200 GeV/c in the region 0.025<|t|<0.095 (GeV/c)2 and MX2s<0.1.
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Measurements of the invariant cross section Ed3σd3p are presented for the production of hadrons (π, K, p, and p¯) at large transverse momentum (p⊥) by 200-, 300-, and 400-GeV protons incident on H2, D2, Be, Ti, and W targets. The measurements were made at a laboratory angle of 77 mrad, which corresponds to angles near 90° in the c.m. system of the incident proton and a single nucleon at rest. The range in p⊥ for the data is 0.77≤p⊥≤6.91 GeV/c, corresponding to values of the scaling variable x⊥=2p⊥s from 0.06 to 0.64. For p−p collisions, the pion cross sections can be represented in the region x⊥>35 by the form (1p⊥n)(1−x⊥)b, with n=8 and b=9. The ratio of π+ to π− production grows as a function of x⊥ to a value larger than 2 at x⊥≳0.5. The ratios of the production of K+ and protons to π+ and of K− and antiprotons to π− also scale with x⊥ for p−p collisions. The K±, p, and p¯ fitted values for n and b are given. Particle ratios are also presented for D2, Be, Ti, and W targets and the dependences on atomic weight (A) are discussed.
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Measurements of inclusive scattering in the target-fragmentation region are extended to higher incident energy. The combined data set shows departures from an approach to the asymptotic scaling limit as A+Bs−12 that are significant even at the highest energies. When these departures are taken into account, the data approach a limit that is consistent with equal cross sections induced by particles and antiparticles and with Pomeron factorization. The corrections to A+Bs−12 are so large that detailed tests of Mueller-Regge relationships are not conclusive.
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Inclusive proton production in pp interactions at 205 GeV/c is studied using the Fermi National Accelerator Laboratory (Fermilab) 30-in. bubble chamber. The invariant cross section is presented in terms of several kinematic variables and compared with similar data obtained from counter experiments at Fermilab and at the CERN Intersecting Storage Rings (ISR). An important feature of this experiment is that it provides data for much wider ranges of the four-momentum transfer than have been attained in the counter experiments. It also gives full information on the associated charged-particle multiplicity of every event, thus permitting a detailed investigation of how various kinematic quantities depend on this parameter.
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We have studied the inclusive production of the hadrons π ± , K ± , p, p , Λ, Λ , ρ and ⋉ in the central region at the ISR s = 53 GeV , in both pp and p p collisions. Differences are observed only for K ± , p, and p production. We then study also correlations between low- p T pp and p p pairs in the two types of collisions, separating the contribution from baryon pair production and from the incident particles (stopping protons). We observe a positive correlation between two stopping protons; between the production of two pairs, and between a stopping proton and a pair production, there are negative correlations.
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The inclusive production cross sections of pions, kaons, protons, and antiprotons in p p and pp interactions at √ s =53 GeV are compared in the kinematic range | y | < 0.8 and p T < 1.5 GeV/ c . We observe differences in the K + /K − and p /p ratios for the two data samples. Although the bulk of the particles are produced with the same momentum and rapidity distributions in p p and pp collisions, we observe difference in these distributions for produced protons and antiprotons.
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We present high-statistics results on the reactions a+p→c+X where a and c can be any of π±, K±, p, or p¯. The data were taken at 100 and 175 GeV/c incident momenta using the Fermilab Single-Arm Spectrometer operated over the kinematic range 0.2<x<1.0 and pt<~1.0 GeV/c. Investigating the x dependence of the data, we find agreement with a quark-parton picture, namely the cross sections have a power-law behavior in 1−x independent of pbeam and pt.
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The ratios of K+, K−, p, and p¯ yields to pion yields at transverse momenta (p⊥) ranging from 0.77 to 6.91 GeV/c arepresented for 200-, 300-, and 400-GeV p−p and 400-GeV p−d collisions. The dependences of the particle ratios on p⊥ and the scaling variable x⊥=2p⊥s are discussed.
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