Multiplicity of Charged Particles in 800-{GeV} $p p$ Interactions

The LEBC-MPS collaboration Ammar, R. ; Aziz, T. ; Banerjee, S. ; et al.
Phys.Lett.B 178 (1986) 124-128, 1986.
Inspire Record 231133 DOI 10.17182/hepdata.6558

Results are reported concerning the charged-particle multiplicity distribution obtained in an exposure of the high-resolution hydrogen bubble chamber LEBC to a beam of 800 GeV protons at the Fermilab MPS. This is the first time that such data have been available at this energy. The distribution of the number n ch of charged particles produced in inelastic interactions obeys KNO-scaling. The average multiplicity is 〈 n ch 〉 = 10.26±0.15. For n ch ⩾8 the data can be well fitted to a negative binomial. The difference between the overall experimental multiplicity distribution and that resulting from the latter fit is in agreement with the contribution expected from diffractive processes.

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Rho0 Production in 205-GeV/c p p Interactions

Singer, R. ; Fields, T.H. ; Hyman, L.G. ; et al.
Phys.Lett.B 60 (1976) 385-388, 1976.
Inspire Record 2818 DOI 10.17182/hepdata.6484

Inclusive and semi-inclusive ρ 0 production are studied in 205 GeV/ c pp interactions. The number of ρ 0 per inelastic event is 0.33 ± 0.06, so that (13 ± 2)% of the π − are products of ϱ 0 decay. The ρ 0 are found to be produced mainly near y = 0 and tend to have larger average transverse momentum than do pions.

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High Transverse Momentum Hadron Hadron Correlations in $\sqrt{s}=38$.8-{GeV} Proton Proton Interactions

Jaffe, D.E. ; Straub, P.B. ; Adams, M.R. ; et al.
Phys.Rev.D 38 (1988) 1016-1019, 1988.
Inspire Record 268868 DOI 10.17182/hepdata.23278

Measurements of correlations of nearly back-to-back hadrons produced at a large transverse momentum in s=38.8 GeV proton-proton collisions are presented and compared to previous results with a beryllium target. The correlations of identified unlike-sign hadron pairs in ratio to the correlation for all unlike-sign pairs are compared with predictions of the Lund model. These predictions differ from the data.

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First results for the two spin parameter A(LL) in pi0 production by 200-GeV polarized protons and anti-protons

The E581 & E704 collaborations Adams, D.L. ; Akchurin, N. ; Belikov, N.I. ; et al.
Phys.Lett.B 261 (1991) 197-200, 1991.
Inspire Record 314233 DOI 10.17182/hepdata.29385

The two-spin parameter A LL in inclusive π 0 productionby longitudinally-polarized protons and antiprotons on a longitudinally-polarized proton target has been measured at the 200 GeV Fermilab spin physics facility, for π 0 's at x F =0 with 1⩽ p t ⩽3 GeV/ c . The results exclude, at the 95% confidence level, values of A LL (pp) > 0.1 and < − 0.1 for π 0 's produced by protons, and values of A LL ( p p) > 0.1 and < −0.2 for incident antiprotons. The relevance of A LL (pp) for the gluon spin density is discussed. The data are in good agreement with “conventional”, small or zero, gluon polarization.

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Comparison of spin asymmetries and cross-sections in pi0 production by 200-GeV polarized anti-protons and protons

The E581 & E704 collaborations Adams, D.L. ; Akchurin, N. ; Belikov, N.I. ; et al.
Phys.Lett.B 261 (1991) 201-206, 1991.
Inspire Record 314232 DOI 10.17182/hepdata.29396
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High x(t) single spin asymmetry in pi0 and eta production at x(F) = 0 by 200-GeV polarized anti-protons and protons

The E581 & E704 collaborations Adams, D.L. ; Akchurin, N. ; Belikov, N.I. ; et al.
Phys.Lett.B 276 (1992) 531-535, 1992.
Inspire Record 314231 DOI 10.17182/hepdata.29252

A measurement of the single-spin asymmetry A N in p↑ + p→ π 0 + X at 200 GeV with x F = 0 shows a transition in the production process from a “ low -x T ” regime with A N = 0, through an intermediate region of negative asymmetry, to a “ high -x T ” regime with A N > 0.3. This transition occurs at x T ≈ 0.4 and is consistent with x T -scaling of A N in pion production using polarized beams or targets from √− s =5.2 to 19.4 GeV. Results for A N in η production by polarized protons and in π 0 production by polarized antiprotons are also presented.

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Analyzing power in inclusive pi+ and pi- production at high x(F) with a 200-GeV polarized proton beam

The FNAL-E704 collaboration Adams, D.L. ; Akchurin, N. ; Belikov, N.I. ; et al.
Phys.Lett.B 264 (1991) 462-466, 1991.
Inspire Record 315569 DOI 10.17182/hepdata.29360

The analyzing power in inclusive charged pion production has been measured using the 200 GeV Fermilab polarized proton beam. A striking dependence in x F is observed in which A N increases from 0 to 0.42 with increasing x F for the π + data and decreases from 0 to −0.38 with increasing x F for π − data. The kinematic range covered is 0.2⩽ x F ⩽0.9 and 0.2⩽ p T ⩽2.0 GeV / c . In a simple model our data indicate that at large x F the transverse spin of the proton is correlated with that of its quark constituents.

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Measurement of the double spin asymmetry A-LL for inclusive multi gamma pair production with 200-GeV/c polarized proton beam and polarized proton target

The FNAL E581/704 collaboration Adams, D.L. ; Akchurin, N. ; Belikov, N.I. ; et al.
Phys.Lett.B 336 (1994) 269-274, 1994.
Inspire Record 378852 DOI 10.17182/hepdata.28569

The invariant double-differential cross section, E 1 E 2 d 6 σ / d p 3 1 d p 3 2 , and the double-spin asymmetry, A LL , for inclusive multi-γ pair production in which γ-rays came from neutral mesons were measured with a 200 GeV / c longitudinally-polarized proton beam and a longitudinally-polarized proton target. Most of the multi-γ pairs comes from two-jet type events which are sensitive to partonic interaction. The A LL values were found to be consistent with zero. The invariant double-differential cross section for inclusive π 0 π 0 production was also measured. These measured cross sections are consistent with LUND Monte Carlo simulations. Using the LUND Monte Carlo simulation package with the Carlitz-Kaur model of spin dependent distribution functions of valence quarks, the A LL values have been compared with theoretical predictions of gluon polarization, ΔG / G . The results put restrictions on the size of ΔG / G in the region of 0.05 ⪅ x ⪅ 0.35.

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Measurement of the Dijet Cross-Section in 400-GeV p p Collisions

The E-609 collaboration Arenton, M.W. ; Ditzler, W.R. ; Fields, T.H. ; et al.
Phys.Rev.Lett. 53 (1984) 1988, 1984.
Inspire Record 15116 DOI 10.17182/hepdata.23566

The invariant cross section for production of jet pairs in 400-GeV/c pp interactions has been measured as a function of pT in the pT range 4 to 9 GeV/c. The results are in good agreement with predictions of perturbative QCD models.

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Experimental Study of the a-Dependence of Inclusive Hadron Fragmentation

Barton, D.S. ; Brandenburg, G.W. ; Busza, W. ; et al.
Phys.Rev.D 27 (1983) 2580, 1983.
Inspire Record 12592 DOI 10.17182/hepdata.23823

Data are presented on the inclusive production of π±, K±, p, and p¯ for π+, K+, and protons incident on nuclear targets at 100 GeV. The results cover the kinematic range 30≤P≤88 GeV/c for Pt=0.3 and 0.5 GeV/c. The observed A dependence of the invariant cross sections exhibits remarkable simplicity, which does not naturally follow from current models of particle production. The results show that the hypothesis of limiting fragmentation can be extended to include collisions with nuclei.

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Measurement of the Single Jet Invariant Cross-section at {Fermilab}

The E609 collaboration Cormell, L.R. ; Arenton, M.W. ; Chen, H.F. ; et al.
Phys.Lett.B 150 (1985) 322-326, 1985.
Inspire Record 206286 DOI 10.17182/hepdata.30447

In an experiment performed at Fermilab we have studied the production of high p t hadron jets from 400 GeV/ c pp interactions. A large solid-angle, towered calorimeter was used to trigger and reconstruct the jet events. We report results for inclusive single-jet production and compare those results with QCD predictions and results obtained at the ISR and the SPS Collider.

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Measurement of the ratio of the production cross sections times branching fractions of $B_{c}^{\pm} \to J/\psi \pi^{\pm}$ and $B^{\pm} \to J/\psi K^{\pm}$ and $\mathcal{B}(B_{c}^{\pm} \to J/\psi \pi^{\pm}\pi^{\pm}\pi^{\mp})/\mathcal{B}(B_{c}^{\pm} \to J/\psi \pi^{\pm})$ in pp collisions at $\sqrt{s} =$ 7 TeV

The CMS collaboration Khachatryan, Vardan ; Sirunyan, Albert M ; Tumasyan, Armen ; et al.
JHEP 01 (2015) 063, 2015.
Inspire Record 1323075 DOI 10.17182/hepdata.39386

The ratio of the production cross sections times branching fractions (sigma(Bc+) B(Bc+ to J/psi pi+))/ (sigma(B+) B(B+ to J/psi K+)) is studied in proton-proton collisions at a center-of-mass energy of 7 TeV with the CMS detector at the LHC. The kinematic region investigated requires Bc+/- and B+/- mesons with transverse momentum pt > 15 GeV and rapidity abs(y) < 1.6. The data sample corresponds to an integrated luminosity of 5.1 inverse femtobarns. The ratio is determined to be [0.48 +/- 0.05 (stat) +/- 0.03 (syst) +/- 0.05 (tau_{Bc})]% The J/psi pi+/- pi+/- pi-/+ decay mode is also observed in the same data sample. Using a model-independent method developed to measure the efficiency given the presence of resonant behaviour in the three-pion system, the ratio of the branching fractions B(Bc+/- to J/psi pi+/- pi+/- pi-/+) / B(Bc+/- to J/psi pi+/-) is measured to be 2.55 +/- 0.80 (stat) +/- 0.33 (syst) +0.04/-0.01 (tau[Bc+]), consistent with the previous LHCb result.

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Real Part of the Proton Proton Forward Scattering Amplitude from 50 GeV to 400 GeV.

Bartenev, V. ; Carrigan, Richard A. ; Chiang, I-Hung ; et al.
Phys.Rev.Lett. 31 (1973) 1367-1370, 1973.
Inspire Record 81733 DOI 10.17182/hepdata.21379

From measurements of proton-proton elastic scattering at very small momentum transfers where the nuclear and Coulomb amplitudes interfere, we have deduced values of ρ, the ratio of the real to the imaginary forward nuclear amplitude, for energies from 50 to 400 GeV. We find that ρ increases from -0.157 ± 0.012 at 51.5 GeV to +0.039 ± 0.012 at 393 GeV, crossing zero at 280 ± 60 GeV.

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Search for Heavy Neutrinos and $W_R$ Bosons with Right-Handed Couplings in a Left-Right Symmetric Model in pp Collisions at $\sqrt{s}$ = 7 TeV

The CMS collaboration Chatrchyan, Serguei ; Khachatryan, Vardan ; Sirunyan, Albert M ; et al.
Phys.Rev.Lett. 109 (2012) 261802, 2012.
Inspire Record 1189986 DOI 10.17182/hepdata.21263

Results are presented from a search for heavy, right-handed muon neutrinos, N[mu], and right-handed W[R] bosons, which arise in the left-right symmetric extensions of the standard model. The analysis is based on a 5.0 inverse femtobarn sample of proton-proton collisions at a center-of-mass energy of 7 TeV, collected by the CMS detector at the Large Hadron Collider. No evidence is observed for an excess of events over the standard model expectation. For models with exact left-right symmetry, heavy right-handed neutrinos are excluded at 95% confidence level for a range of neutrino masses below the W[R] mass, dependent on the value of M(W[R]). The excluded region in the two-dimensional (M(W[R]), M(N[mu])) mass plane extends to M(W[R]) = 2.5 TeV.

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A Comparison of the Shapes of pi+ p and p p Diffraction Peaks from 50-GeV/c to 175-GeV/c

The Fermilab Single Arm Spectrometer Group collaboration Ayres, D.S. ; Diebold, Robert E. ; Maclay, G.J. ; et al.
Phys.Rev.Lett. 37 (1976) 548, 1976.
Inspire Record 108238 DOI 10.17182/hepdata.21073

The ratio of π+p to pp elastic scattering is found to be smoothly varying over the range −t=0.03 to 0.4 GeV2. It is well fitted by a single exponential, indicating the forward behavior must be quite similar for the two reactions.

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Measurement of the Slope of the Diffraction Peak for Elastic pp Scattering from 8-GeV to 400-GeV.

Bartenev, V. ; Kuznetsov, A. ; Morozov, B. ; et al.
Phys.Rev.Lett. 31 (1973) 1088-1091, 1973.
Inspire Record 81722 DOI 10.17182/hepdata.21381

The slope b(s) of the forward diffraction peak of p−p elastic scattering has been measured in the momentum-transfer-squared range 0.005≲|t|≲0.09 (GeV/c)2 and at incident proton energies from 8 to 400 GeV. We find that b(s) increases with s, and in the interval 100≲s≲750 (GeV)2 it can be fitted by the form b(s)=b0+2α′lns with b0=8.23±0.27, α′=0.278±0.024 (GeV/c)−2.

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Barish, S.J. ; Colley, D.C. ; Schultz, P.F. ; et al.
Phys.Rev.Lett. 31 (1973) 1080-1083, 1973.
Inspire Record 81790 DOI 10.17182/hepdata.21407

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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pp Interactions at 303 GeV/c: Inclusive Studies of Gamma, $K^0_S$, and $\Lambda^0$ Production.

Dao, F.T. ; Gordon, D. ; Lach, J. ; et al.
Phys.Rev.Lett. 30 (1973) 1151-1154, 1973.
Inspire Record 81780 DOI 10.17182/hepdata.21419

From analysis of V0 events observed in an exposure of the National Accelerator Laboratory 30-in. bubble chamber to 303−GeVc protons, we obtain these results: (1) 〈nπ0〉 rises approximately linearly with n-, implying strong coupling of neutral and charged pions, while 〈nKS0〉 is less coupled to n; (2) γ, KS0, and Λ0 production cross sections are approaching a scaling limit by 303 GeVc; (3) within the limited statistics, dσdy is flat in the central region for KS0 and low-multiplicity γ events.

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Small Angle Elastic Proton Proton Scattering from 25-GeV to 200-GeV.

Bartenev, V. ; Kuznetsov, A. ; Morozov, B. ; et al.
Phys.Rev.Lett. 29 (1972) 1755-1758, 1972.
Inspire Record 73778 DOI 10.17182/hepdata.21428

We have measured the differential cross section for small angle p−p scattering from 25 to 200 GeV incident energy and in the momentum transfer range 0.015<|t|<0.080 (GeVc)2. We find that the slope of the forward diffraction peak, b(s), increases with energy and can be fitted by the form b(s)=b0+2α′ lns, where b0=8.3±1.3 and α′=0.28±0.13 (GeVc)−2. Such dependence is compatible with the data existing both at higher and lower energies. We have also obtained the energy dependence of the p−p total cross section in the energy range from 48 to 196 GeV. Within our errors which are ± 1.1 mb the total cross section remains constant.

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p p Interactions at 303-GeV/c: Multiplicity and Total Cross-Section.

Dao, F.T. ; Gordon, D. ; Lach, J. ; et al.
Phys.Rev.Lett. 29 (1972) 1627-1630, 1972.
Inspire Record 73776 DOI 10.17182/hepdata.21429

In an exposure of the 30-in. hydrogen bubble chamber to a 303−GeVc proton beam, 2245 interactions have been observed. The measured total cross section is 39.0±1.0 mb and the average charged particle multiplicity 〈nch〉=8.86±0.16.

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Charged Particle Multiplicity Distribution from 200-GeV p p Interactions

Charlton, G. ; Cho, Y. ; Derrick, M. ; et al.
Phys.Rev.Lett. 29 (1972) 515, 1972.
Inspire Record 73783 DOI 10.17182/hepdata.21430

From 2728 events of 205-GeV pp interactions found in 15 000 pictures taken with the 30-in. hydrogen bubble chamber at the National Accelerator Laboratory, a total cross section of 39.5±1.1 mb was measured. The mean charged-particle multiplicity for inelastic pp collisions was measured to be 7.65±0.17. The prong distribution from 2 to 22 prongs is broader than a Poisson distribution and has a width parameter f2−=〈n−(n−−1)〉−〈n−〉2=0.95±0.21.

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Total Cross-Sections of $p$ and $\bar{p}$ on Protons and Deuterons Between 50-GeV/c and 200-GeV/c

Carroll, A.S. ; Chiang, I.-H. ; Kycia, T.F. ; et al.
Phys.Rev.Lett. 33 (1974) 928, 1974.
Inspire Record 90202 DOI 10.17182/hepdata.21291

Proton and antiproton total cross sections on protons and deuterons have been measured at 50, 100, 150, and 200 GeV/c. The proton cross sections rise with increasing momentum. Antiproton cross sections fall with increasing momentum, but the rate of fall decreases between 50 and 150 GeV/c, and from 150 to 200 GeV/c there is little change in cross section.

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Inelastic Diffractive Scattering at FNAL Energies

Ayres, D.S. ; Diebold, Robert E. ; Cutts, D. ; et al.
Phys.Rev.Lett. 37 (1976) 1724, 1976.
Inspire Record 109174 DOI 10.17182/hepdata.21057

Inelastic differential cross sections have been measured for π±p, K±p, and p±p at 140- and 175-GeV/c incident momentum over a |t| range from 0.05 to 0.6 GeV2 and covering a missing-mass region from 2.4 to 9 GeV2. For Mx2 greater than 4 GeV2, the invariant quantity Mx2d2σdtdMx2 was found to be independent of Mx2 at fixed t and could be adequately described by a simple triple-Pomeron form. The values obtained for the triple-Pomeron couplings are identical within statistics for all channels.

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A Measurement of High $P_T$ Correlations in 340-GeV/c pp and 280-GeV/c $\pi^- p$ Reactions

Oliver, W.P. ; Limon, P. ; Mantsch, Paul M. ; et al.
Nucl.Phys.B 228 (1983) 439-463, 1983.
Inspire Record 189533 DOI 10.17182/hepdata.33923

We have measured correlations between single high- p T (1.5< p T <3.5 GeV/ c ) trigger particles on one side of the beam line and groups of particles entering a calorimeter on the opposite side of the beam line. The mean transverse momentum measured in the calorimeter is found to increase with the trigger-particle transverse momentum. The coplanarity of the events increases with trigger-particle transverse momentum. We have compared our data with the predictions of a phenomenological four-jet model. To fit our data we find that we must give large (0.9 GeV/ c ) mean transverse momenta to the constituents of the initial hadrons.

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Measurement of Top Quark Polarisation in T-Channel Single Top Quark Production

The CMS collaboration Khachatryan, Vardan ; Sirunyan, Albert M ; Tumasyan, Armen ; et al.
JHEP 04 (2016) 073, 2016.
Inspire Record 1403169 DOI 10.17182/hepdata.38092

A first measurement of the top quark spin asymmetry, sensitive to the top quark polarisation, in t-channel single top quark production is presented. It is based on a sample of pp collisions at a centre-of-mass energy of 8 TeV corresponding to an integrated luminosity of 19.7 inverse-femtobarns. A high-purity sample of t-channel single top quark events with an isolated muon is selected. Signal and background components are estimated using a fit to data. A differential cross section measurement, corrected for detector effects, of an angular observable sensitive to the top quark polarisation is performed. The differential distribution is used to extract a top quark spin asymmetry of 0.26 +/- 0.03 (stat) +/- 0.10 (syst), which is compatible with a p-value of 4.6% with the standard model prediction of 0.44.

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