10335512
Antilambda production in Au+Au collisions at 11.7A GeV/c.
We present results for antilambda and antiproton production in Au+Au collisions at 11.7 A GeV/c including spectra and extracted invariant yields for both species in central and peripheral collisions in the rapidity range 1.0<y<1.4. The antilambda yield increases from dN(Lambda;)/dy = 1.2(+0.7+0.2)(-0.6-0.2)x10(-3) in peripheral collisions to 19(+4+3)(-5-2)x10(-3) in central collisions. The direct antiproton yield is deduced from the measured total antiproton spectra to extract the ratio of antilambda-to-direct-antiproton production. The Lambda/p ratio near midrapidity increases from 0.26(+0.19+0.5)(-0.15-0.4) in peripheral collisions to 3.6(+4.7+2.7)(-1.8-1.1) in central collisions, a value larger than current theoretical estimates.
34566683
Sign of the neutron-proton mass difference in an SU(2) x U(1) supersymmetric toy model: A possible scenario for solving the old puzzle.
Based on the idea that electromagnetism is responsible for mass differences within isotopic multiplets (e.g., pointlike neutron and proton or {ital u} and {ital d} quarks), we generalize an SU(2){times}U(1) model in a toy field theory of vectors to a supersymmetric model and investigate the finite mass difference within the isotopic doublet. It is found that under soft-supersymmetry breaking, a positive {ital n}-{ital p} mass difference can be obtained under reasonable assumptions for the parameters involved.
30310361
Purely gluonic soliton solutions in the leading-logarithm model.
Finite-energy, purely gluonic, soliton solutions are considered in atwo-dimensional space on the basis of the leading-logarithm model which isequivalent to electromagnetism with a dielectric constant /epsilon/logarithmically proportional to the fields. Solutions, in the absence ofsources, are possible provided /epsilon//gt/0 and /epsilon//lt/0 are bothpresent in the same space.
120551902
Rapidity density distributions and their fluctuations in violent Au-induced nuclear interactions at 11.6 A GeV/c
The first rapidity density distributions from relativistic collisions between truly heavy nuclei are presented. The distributions are compared with expectations from a linear extrapolation of results obtained from collisions with lighter nuclei. Fluctuations are essentially described by a simple scenario with stochastic emission.
202105722
Search for strong gravity signatures in same-sign dimuon final states using the ATLAS detector at the LHC
A search for microscopic black holes has been performed in a same-sign dimuon final state using 1.3 fb(-1) of proton-proton collision data collected with the ATLAS detector at a centre of mass energy of 7 TeV at the CERN Large Hadron Collider. The data are found to be consistent with the expectation from the Standard Model and the results are used to derive exclusion contours in the context of a low scale gravity model.
123878919
Partial wave analysis of J/psi ---> p anti-p pi0
Using a sample of 58 million J/{psi} events collected with the BESII detector at the BEPC, more than 100 000 J/{psi}{yields}pp{pi}{sup 0} events are selected, and a detailed partial wave analysis is performed. The branching fraction is determined to be Br(J/{psi}{yields}pp{pi}{sup 0})=(1.33{+-}0.02{+-}0.11)x10{sup -3}. A long-sought missing N*, first observed in J/{psi}{yields}pn{pi}{sup -}, is observed in this decay too, with mass and width of 2040{sub -4}{sup +3}{+-}25 MeV/c{sup 2} and 230{sub -8}{sup +8}{+-}52 MeV/c{sup 2}, respectively. Its spin-parity favors (3/2){sup +}. The masses, widths, and spin parities of other N* states are obtained as well.
121660884
Limiting Fragmentation, Scaling and Substructual Dependence of Multiparticle Production in High Energy Heavy Ion Reactions
We report on recent results obtained by the EMUO1 collaboration from studies of 16O + emulsion, at 14.6, 60 and 200 A GeV, and 32S + emulsion and 32S + Au interactions at 200 A GeV. Shower-particle production in oxygen-induced interactions are studied over the energy range 2.1-200 A GeV. Scaling and limiting fragmentation are observed. Multiplicity and angular distributions of low energy target-associated particles are presented and compared with distributions obtained using the Ranft and the Fritiof simulation codes.
119358213
Partial wave analysis of J / psi --> gamma (eta pi+ pi-)
Abstract A partial wave analysis of BES J / ψ → γ ( ηπ + π − ) data has been performed in the mass region 1.1 to 2.0 GeV. A peak is observed due to η (1440) in the ηπ + π − invariant mass distribution; J P =0 − is preferred over 1 + . Its mass is M =1385±7 MeV and it decays into both ησ and a 0 (980) π , with BR[ a 0 (980) π , a 0 → ηπ / ησ ]=0.70±0.12( stat )±0.20( syst ). Destructive interference between the two decay modes is observed. In addition, in the higher ηπ + π − mass region, there is a definite 2 −+ signal, with M =1840±15 MeV and Γ =170±40 MeV and an additional 0 −+ signal at 1760±35 MeV. We also find a possible contribution from a 1 ++ signal decaying dominantly through a 0 (980) π ; its mass and width are fitted to be M =1505±20 MeV and Γ =130 −20 +50 MeV.