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).
Data from p+p→p+X at 102, 205, and 405 GeV and from π−+p→p+X at 205 GeV exhibit an approximate scaling property in the charged-prong multiplicity distributions as a function of the missing mass for the range 5<~MX<~13 GeV.
No description provided.
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.
None
No description provided.
No description provided.
No description provided.
Inclusive π− distributions from 205-GeV/c pp interactions, covering the full range of longitudinal and transverse momenta, have been obtained using the 30-in. hydrogen bubble chamber at the National Accelerator Laboratory. These data provide new evidence for scaling in the fragmentation region and for a plateau in the central region of rapidity. The 90°-c.m. invariant cross section varies as exp[−(10±2)PT2] in the range PT2<~0.1 (GeV/c)2.
No description provided.
By using (pp) interactions at three different c.m. energies,\(\left( {\sqrt 8 } \right)_{pp} \)=30, 44, 62 GeV, it is shown that the average charged-particle multiplicity <nch>vs. the invariant mass of the hadronic systemm1,2 has the same behaviour as it hasvs. 2Ehad. Moreover, in both cases <nch> is shown to be nearly independent of\(\left( {\sqrt 8 } \right)_{pp} \) and in good agreement with the average charged-particle multiplicity measured in the (e+e−) annihilation.
WITH SQRT(S) OF 30 GEV.
WITH SQRT(S) OF 44 GEV.
WITH SQRT(S) OF 62 GEV.
The differential cross section of pp scattering has been measured in the energy region 100–300 GeV and in the t -range 0.002 < | t | < 0.04 (GeV/| c ) 2 . The results on the real part of the scattering amplitude agrees with dispersion relation calculations. We also report on our determination of the slope parameter b together with an analysis of the world data of b for different hadrons and different t -values. It is shown that the data are consistent with the hypothesis of a universal shrinkage of the hadronic diffraction cone at high energies.
FROM FITS TO D(SIG)/DT IN THE COULOMB-NUCLEAR INTERFERENCE REGION, USING TOTAL CROSS SECTION VALUES FROM A. S. CARROLL ET AL., PL 80B, 423 (1979). ERRORS INCLUDE STATISTICAL ERRORS AND ERRORS IN NORMALIZATION AND IN SIG.
By using three different c.m. energies in pp interactions,\(\sqrt s \), 44, 62 GeV, it is shown that the average charged-particle multiplicity <nch> sclaes with\(\sqrt s \) once the correct hadronic energy available for multiparticle production,Ehad, is used as basic parameter. The pp data, analysed in this way, are compared with e+e− data at equivalent energies. The agreement is very satisfactory.
WITH SQRT(S) OF 30 GEV.
WITH SQRT(S) OF 44 GEV.
WITH SQRT(S) OF 62 GEV.
The average charged multiplicity in proton-proton interactions has been studied at √ s = 62 GeV. A very good agreement with the average charged multiplicity measured in e + e − annihilation at different energies is obtained by redefining, in p-p, the correct energies available for particle production. This means that a p-p collision at √ s = 62 GeV does in fact correspond to a large range of effective hadronic energies available for particle production.
AVERAGE CHARGED MULTIPLICITY AS A FUNCTION OF HADRONIC ENERGY WHERE E(NAME=HAD) IS THE INCIDENT PROTON ENERGY (COLLIDING BEAM ENERGY) MINUS THE LEADING PROTON ENERGY.
Forum