The Multiplicity dependence of inclusive p(t) spectra from p-p collisions at s**(1/2) = 200-GeV

The STAR collaboration Adams, J. ; Aggarwal, M.M. ; Ahammed, Z. ; et al.
Phys.Rev.D 74 (2006) 032006, 2006.
Inspire Record 719969 DOI 10.17182/hepdata.102084

We report measurements of transverse momentum $p_t$ spectra for ten event multiplicity classes of p-p collisions at $\sqrt{s} = 200$ GeV. By analyzing the multiplicity dependence we find that the spectrum shape can be decomposed into a part with amplitude proportional to multiplicity and described by a L\'evy distribution on transverse mass $m_t$, and a part with amplitude proportional to multiplicity squared and described by a gaussian distribution on transverse rapidity $y_t$. The functional forms of the two parts are nearly independent of event multiplicity. The two parts can be identified with the soft and hard components of a two-component model of p-p collisions. This analysis then provides the first isolation of the hard component of the $p_t$ spectrum as a distribution of simple form on $y_t$.

5 data tables

FIG. 1: Corrected and normalized charged-particle spectra on transverse momentum $p_t$ (left) and transverse rapidity $y_t$ (right) for 10 event multiplicity classes, displaced upward by successive factors 40 relative to $\hat{n}_{ch}$ = 1 at bottom. Solid curves represent reference function $n_s/n_{ch} · S_0(y_t)$ (cf.Sec. IV C). Dotted curves are spline fits to guide the eye.

FIG. 1: Corrected and normalized charged-particle spectra on transverse momentum $p_t$ (left) and transverse rapidity $y_t$ (right) for 10 event multiplicity classes, displaced upward by successive factors 40 relative to $\hat{n}_{ch}$ = 1 at bottom. Solid curves represent reference function $n_s/n_{ch} · S_0(y_t)$ (cf.Sec. IV C). Dotted curves are spline fits to guide the eye.

FIG. 2. Left: Relative residuals from power-law fits to $p_{t}$ spectra in Fig. 1. The hatched band represents the expected statistical errors for STAR data. Right: Exponents $n$ from power-law fits to data (solid points) and to corresponding twocomponent fixed-model functions (open circles, see Sec. VI) compared to the two-component fixed-model Lévy exponent $12.8 \pm 0.15$ (hatched band). NOTE 1: For points with invisible error bars, the point size was considered as an absolute upper limit for the uncertainty. NOTE 2: The "data_stat" uncertainty corresponds to the expected statistical error (hatched band).

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QCD studies with e+ e- annihilation data at 172-GeV to 189-GeV.

The OPAL collaboration Abbiendi, G. ; Ackerstaff, K. ; Akesson, P.F. ; et al.
Eur.Phys.J.C 16 (2000) 185-210, 2000.
Inspire Record 513476 DOI 10.17182/hepdata.49000

We have studied hadronic events from e+e- annihilation data at centre-of-mass energies of sqrt{s}=172, 183 and 189 GeV. The total integrated luminosity of the three samples, measured with the OPAL detector, corresponds to 250 pb^-1. We present distributions of event shape variables, charged particle multiplicity and momentum, measured separately in the three data samples. From these we extract measurements of the strong coupling alpha_s, the mean charged particle multiplicity <nch> and the peak position xi_0 in the xi_p=ln(1/x_p) distribution. In general the data are described well by analytic QCD calculations and Monte Carlo models. Our measured values of alpha_s, <nch> and xi_0 are consistent with previous determinations at sqrt{s}=MZ.

20 data tables

Distribution of Thrust.

Distribution of Thrust Major.

Distribution of Thrust Minor.

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Momentum correlations of charmed pairs produced in pi- - Cu interactions at 230-GeV/c

Rybicki, K. ; Rylko, R. ;
Phys.Lett.B 353 (1995) 547-553, 1995.
Inspire Record 394891 DOI 10.17182/hepdata.28510

We study the production characteristics of 557 pairs of charmed hadrons produced in $\pi~{-}-Cu$\ interactions at 230GeV/c using a momentum estimator for charmed hadrons with missing decay products. We find, the mean value of the transverse momentum squared of the charmed pairs is $<$\pts$>=(1.98\pm 0.11\pm 0.09)\;$ GeV$~2$/c$~2$, the mean rapidity difference is $<|$\yd$|>=0.54\pm 0.02\pm 0.24$, and the mean effective mass is $<$\mef$>=(4.45\pm 0.03\pm 0.13)\;$ GeV/c$~2$. Comparing these results with the next-to-leading order QCD predictions we find an agreement for the \yd\ and \mef, whilst the measured mean value of \pts\ is significantly larger than the predicted value.

1 data table

No description provided.


Projectile rapidity pions in 775-MeV/nucleon La-139 + C-12 and La-139 + La-139 reactions

Hashimoto, O. ; Hamagaki, H. ; Kobayashi, T. ; et al.
Phys.Rev.C 49 (1994) 420-427, 1994.
Inspire Record 383725 DOI 10.17182/hepdata.25980

Negative pion spectra emitted in the reactions of 775 MeV/nucleon La139+12C and La139+139La reactions have been measured in coincidence with the projectile fragments using the HISS spectrometer at the Bevalac. Prominent peaks near the beam velocity were observed in the pion spectra. Position and widths of the peaks were studied as a function of the ‘‘sum charge’’ of projectile fragments which is a good measure of impact parameter; the smaller the ‘‘sum charge,’’ the smaller the impact parameter. The peak position down shifts with the smaller ‘‘sum charge.’’ The pion peak is wider in the transverse than in the longitudinal direction, possibly mirroring the velocity dispersions of projectile fragments in the early stage of reactions.

2 data tables

THE CHARGE IN THE TABLE IS THE SUM CHARGE OF OBSERVED FRAGB. A TWO-DIMENSIONAL SPECTRUM WAS FITTED BY A SINGLE TWO-DIMENSIONAL GAUSSIAN FUNCTION ON A FLAT BACKGROUND.

THE CHARGE IN THE TABLE IS THE SUM CHARGE OF OBSERVED FRAGB. A TWO-DIMENSIONAL SPECTRUM WAS FITTED BY A SINGLE TWO-DIMENSIONAL GAUSSIAN FUNCTION ON A FLAT BACKGROUND.


Charmed pair correlations in pi- Cu interactions at 230-GeV/c.

The ACCMOR collaboration Barlag, S. ; Becker, H. ; Bożek, A. ; et al.
Phys.Lett.B 302 (1993) 112-118, 1993.
Inspire Record 362064 DOI 10.17182/hepdata.28956

In the CERN NA32 experiment a high-resolution silicon vertex detector and a purely topological approach were used to collect 557 events consistent with associated charm production, both decay vertices being observed. The pseudorapidity gap distribution appears to be nearly independent of the nature of the charmed hadrons. This distribution is reasonably consistent with the next-to-leading order QCD calculations. However the azimuthal-angle distribution is significantly broader than the above predictions.

2 data tables

FOR ONLY 20 EVENTS IN WICH BOTH DECAYS ARE FULLY RECONSTRUCTED ( 26 D0 , 8 D+ , 5 D/S+ , 1 LAMBDA/C+ CHARMED PARTICLES ).

No description provided.


Comparative Characteristics of Central and Noncentral C C Interactions at 4.2-{GeV} Per Nucleon

Agakishiev, G.N. ; Backovic, S. ; Boldea, V. ; et al.
Sov.J.Nucl.Phys. 51 (1990) 481-485, 1990.
Inspire Record 285507 DOI 10.17182/hepdata.17258

None

5 data tables

No description provided.

No description provided.

P - IS PROTON-PARTICIPANTS, ITS NUMBER WAS DEFINED AS FOLLOWS: N(P)=N+ - N - N(S,P) - N(S,T), WHERE N+ , N- - NUMBER OF MULT(CHARGED) PARTICLES WITH Z=+1 AND Z=-1, N(S,P), N(S,T) - NUMBER OF STRIPPING PARTICLES WITH Z=1 FROM PROJECTILE (P>3 GEV, THETA<4 DEG) AND TARGET (P<0.3 GEV FOR PROTONS).

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Production of $\Lambda$ Hyperons and $K^0(s$) Mesons in Annihilation of Anti-protons in $^{4}$He Nuclei at 600-{MeV}/$c$

Batusov, Yu.A. ; Bunyatov, S.A. ; Falomkin, I.V. ; et al.
Sov.J.Nucl.Phys. 50 (1989) 945-948, 1989.
Inspire Record 280132 DOI 10.17182/hepdata.39439

None

4 data tables

43 EVENTS WITH LAMBDA, 54 EVENTS WITH KS.

43 EVENTS WITH LAMBDA, 54 EVENTS WITH KS.

43 EVENTS WITH LAMBDA, 54 EVENTS WITH KS. D(N)/D(P) WAS FITTED BY P**2*EXP(-SLOPE*EKIN).

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Central Mg + Mg collisions with Lambda production at a momentum of 4.3-GeV/c per nucleon

Avramenko, S.A. ; Abdurakhimov, A.U. ; Aksinenko, V.D. ; et al.
Sov.J.Nucl.Phys. 55 (1992) 400-407, 1992.
Inspire Record 319240 DOI 10.17182/hepdata.38716

None

2 data tables

CENTRAL COLLISIONS.

CENTRAL COLLISIONS.


Experimental study of b quark jets in e+ e- annihilation at TRISTAN

The TOPAZ collaboration Nagai, K. ; Enomoto, R. ; Abe, T. ; et al.
Phys.Lett.B 278 (1992) 506-510, 1992.
Inspire Record 333342 DOI 10.17182/hepdata.29230

An experimental study of b-quark jets using high- p T electrons was carried out at √ s =58 GeV with the TOPAZ detector at the e + e − collider TRISTAN at KEK. The forward-backward charge asymmetry of the b-quark was obtained to be A b b ̄ =−0.55±0.27( stat. )±0.07( syst. ) , consistent with the standard model prediction. Also, such jet properties of the b-quark as the average charged multiplicity and the rapidity of charged particles were analyzed. In order to purify the b-quark event samples in this analysis, only events with backward-going electrons or forward-going positrons were used. The energy dependence of these jet properties was studied by making comparisons with the results of the DELCO experiment at the PEP collider (√ s =29 GeV) at SLAC.

4 data tables

No description provided.

No description provided.

Mean values of jet properties for b-jet sample.

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Multiplicity, Momentum and Angular Characteristics of $\pi^-$ Mesons for $p$ C, $d$ C, $\alpha$ C and C C Interactions at 4.2-{GeV}/$c$ Per Nucleon

The Alma Ata-Baku-Belgrade-Bucharest-Dubna-Kishinev-Leipzig- Moscow-Prague-Samarkand-Sofiya-Tashkent-Tbilisi-Ulan Bator-Varna collaboration Agakishiev, G.N. ; Akhababian, N. ; Armutliisky, D. ; et al.
Z.Phys.C 27 (1985) 177, 1984.
Inspire Record 203342 DOI 10.17182/hepdata.1999

Light ion collisions with carbon target at 4.2 GeV/c/N are studied. Pion multiplicity distributions, momentum and angular spectra are analysed. These data are described in terms of models assuming independent interactions of nucleons from the projectile nucleus with the target.

18 data tables

No description provided.

No description provided.

No description provided.

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