We present the first measurements of femtoscopic correlations between the K$^0_{\rm S}$ and K$^{\rm \pm}$ particles in pp collisions at $\sqrt{s}=7$ TeV measured by the ALICE experiment. The observed femtoscopic correlations are consistent with final-state interactions proceeding solely via the $a_0(980)$ resonance. The extracted kaon source radius and correlation strength parameters for K$^0_{\rm S}$K$^{\rm -}$ are found to be equal within the experimental uncertainties to those for K$^0_{\rm S}$K$^{\rm +}$. Results of the present study are compared with those from identical-kaon femtoscopic studies also performed with pp collisions at $\sqrt{s}=7$ TeV by ALICE and with a K$^0_{\rm S}$K$^{\rm \pm}$ measurement in Pb-Pb collisions at $\sqrt{s_{\rm NN}}=2.76$ TeV. Combined with the Pb-Pb results, our pp analysis is found to be compatible with the interpretation of the $a_0(980)$ having a tetraquark structure instead of that of a diquark.
Raw K0s K+ correlation function for all kT
Raw K0s K+ correlation function for kT < 0.85 GeV/c
Raw K0s K+ correlation function for kT > 0.85 GeV/c
We have measured the inclusive production of J ψ in 16 and 22 GeV π − copper collisions in a wide aperture magnetic spectrometer. The cross section per Cu nucleus for x > 0 corrected for branching ratio is 64 ± 38 nb at 16 GeV and 196 ± 38 nb at 22 GeV. As threshold is approached, the mean values of the Feynman x distribution increase and the cross section for J ψ production drops steeply. This can be understood in terms of the quark-fusion model where the antiquark content of the pion makes an increasingly significant contribution as M 2 s increases.
A comprehensive survey of event-by-event fluctuations of charged hadron multiplicity in relativistic heavy ions is presented. The survey covers Au+Au collisions at sqrt(s_NN) = 62.4 and 200 GeV, and Cu+Cu collisions sqrt(s_NN) = 22.5, 62.4, and 200 GeV. Fluctuations are measured as a function of collision centrality, transverse momentum range, and charge sign. After correcting for non-dynamical fluctuations due to fluctuations in the collision geometry within a centrality bin, the remaining dynamical fluctuations expressed as the variance normalized by the mean tend to decrease with increasing centrality. The dynamical fluctuations are consistent with or below the expectation from a superposition of participant nucleon-nucleon collisions based upon p+p data, indicating that this dataset does not exhibit evidence of critical behavior in terms of the compressibility of the system. An analysis of Negative Binomial Distribution fits to the multiplicity distributions demonstrates that the heavy ion data exhibit weak clustering properties.
The mean from the NBD fit as a function of $N_{part}$ for 200 GeV Au+Au collisions over the range 0.2 < $p_T$ < 2.0 GeV/$c$.
The mean from the NBD fit as a function of $N_{part}$ for 62.4 GeV Au+Au collisions over the range 0.2 < $p_T$ < 2.0 GeV/$c$.
We have measured the differential cross section d2σdΩdTπ and the polarization parameter P for the production of π+ and π− in various target nuclei (H1, H2, Be, C, O, Al, Ni, Cu, Mo, and Pb) by protons with a kinetic energy of 585 MeV, for production angles θπ=22.5°, 45°, 60°, 90°, and 135°, and for pion kinetic energies Tπ of 24, 35, 46, 88, 151, 192, and 254 MeV (all quantities in the laboratory system). Our data disagree strongly with recent data for 580-MeV protons. On the other hand, for pion energies up to 150 MeV, our cross sections differ little from those measured for a proton energy of 730 MeV. For nuclei with A>20, the total production cross sections σ(π+) and σ(π−) show the Z13 and N23 proportionality expected from theoretical arguments. There is evidence in our data of a shift of the π+ energy distributions compared to the π− distributions due to the effects of the Coulomb field of the nuclear protons on the emitted pions. NUCLEAR REACTIONS H1, H2, Be, C, O, Al, Ni, Cu, Mo, Pb p, π±, Tp=585 MeV; measured σ(Tπ, θπ) and asymmetry parameter P(Tπ, θπ).
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We report on a measurement of the differential cross sections of inclusive$K^{\pm}_{890}$production in$\sigma^-, pi^-$and ne
The production cross sections for K*+- per nucleus and per nucleon for the SIGMA- beam.
The production cross sections for K*+- per nucleus and per nucleon for the PI- beam.
The production cross sections for K*+- per nucleus and per nucleon for the NEUTRON- beam.
The differential cross sections for antiproton elastic scattering on 4 He at 192.8 MeV/ c are measured. The annihilation cross section σ a = (377.6 ± 8.0) mb, the elastic cross section σ el = (206.3 ± 6.6) mb and the total p 4 He interaction cross section σ tot = (583.9 ± 10.4) mb are determined. The ratio of the real to imaginary part of the forward p 4 He amplitude is found: π =−0.17± 0.33 0.24 . Partial wave analysis reveals that the S, P and D waves are essential in this energy region.
Charged prong multiplicity distributions in pbar HE annihilation.
Mean charged particle multiplicity in pbar HE4 annihilations.
No description provided.
The production of the Lambda and Sigma0 hyperons has been measured via the pp->pK+Lambda / Sigma0 reaction at the internal COSY-11 facility in the excess energy range between 14 and 60 MeV. The transition of the Lambda/Sigma0 cross section ratio from about 28 at Q<=13 MeV to the high energy level of about 2.5 is covered by the data showing a strong decrease of the ratio between 10 and 20 MeV excess energy. Effects from the final state interactions in the p-Sigma0 channel seem to be much smaller compared to the p-Lambda one. Estimates of the effective range parameters are given for the N-Lambda and the N-Sigma systems.
Cross section for LAMBDA production.. Statistical errors only.
Cross section for SIGMA0 production.. Statistical errors only.
Energy dependence of the LAMBDA/SIGMA0 ratio.
The proton-to-pion ratios measured in the BRAHMS experiment for Au+Au and p+p collisions at $\sqrt{s_{NN}}$ = 62.4 and 200 GeV are presented as a function of transverse momentum and collision centrality at selected pseudorapidities in the range of 0 to 3.8. A strong pseudorapidity dependence of these ratios is observed. We also compare the magnitude and p_T-dependence of the p/pi ratios measured in Au+Au collisions at \rootsnn{200} and $\eta \approx 2.2$ with the same ratio measured at \rootsnn{62.4} and $\eta = 0$. The great similarity found between these ratios throughout the whole p_T range (up to 2.2 GeV/$c$) is consistent with particle ratios in A+A collisions being described with grand-canonical distributions characterized by the baryo-chemical potential \mibn. At the collision energy of 62.4 GeV, we have observed a unique point in pseudorapidity, $\eta = 3.2$, where the p/pi+ ratio is independent of the collision system size in a wide p_T-range of $0.3 \le p_{T} \le 1.8$ GeV/$c$.
$\mathrm{p}/\mathrm{\pi}^{+}$ versus $p_{\mathrm{T}}$ for $\mathrm{\pi}^{+}$, $\mathrm{p}$ in $\mathrm{Au}-\mathrm{Au}$ at $\sqrt{s_{\mathrm{NN}}}=200\,\mathrm{Ge\!V}$
$\mathrm{p}/\mathrm{\pi}^{+}$ versus $p_{\mathrm{T}}$ for $\mathrm{\pi}^{+}$, $\mathrm{p}$ in $\mathrm{Au}-\mathrm{Au}$ at $\sqrt{s_{\mathrm{NN}}}=200\,\mathrm{Ge\!V}$
$\mathrm{p}/\mathrm{\pi}^{+}$ versus $p_{\mathrm{T}}$ for $\mathrm{\pi}^{+}$, $\mathrm{p}$ in $\mathrm{Au}-\mathrm{Au}$ at $\sqrt{s_{\mathrm{NN}}}=200\,\mathrm{Ge\!V}$
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No description provided.
No description provided.
We have used the spin-precession technique to measure the Σ− magnetic moment (μΣ). A Σ− beam with a polarization of 22% was produced by a 400-GeV proton beam striking a Cu target at nominal production angles of ±3 mrad. We simultaneously recorded 21 000 Σ−→ne−ν¯ decays and 650 000 Σ−→nπ− decays at Σ− beam momenta of 253 and 308 GeV/c. We find μΣ=−1.166±0.014±0.010 nuclear magnetons, where the quoted errors are statistical and systematic, respectively.
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