Search results for "upsilon mesons"

showing 2 items of 2 documents

Search for a Stable Six-Quark State at BABAR

2019

Recent investigations have suggested that the six-quark combination uuddss could be a deeply bound state (S) that has eluded detection so far, and a potential dark matter candidate. We report the first search for a stable, doubly strange six-quark state in Upsilon -> S anti-Lambda anti-Lambda decays based on a sample of 90 million Upsilon(2S) and 110 million Upsilon(3S) decays collected by the BABAR experiment. No signal is observed, and 90% confidence level limits on the combined Upsilon(2S,3S) -> S anti-Lambda anti-Lambda branching fraction in the range (1.2-1.4)x10^-7 are derived for m_S < 2.05 GeV. These bounds set stringent limits on the existence of such exotic particles.

:Kjerne- og elementærpartikkelfysikk: 431 [VDP]branching ratio: upper limitElectron–positron annihilationBound stateGeneral Physics and AstronomyBaBar experimentQuarksUpsilon(10355): rare decayUpsilon(10355): electroproductionUpsilon(10020): branching ratioparticle: exoticupsilon mesons: hadronic decay01 natural sciencesdecayHigh Energy Physics - ExperimentHigh Energy Physics - Experiment (hep-ex)Upsilon(10020): electroproductionBound state[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]PhysicQCQBExotic particlesPhysicsnew physics: search forSettore FIS/01 - Fisica Sperimentaleelectron positron: colliding beamsdetector limits decay:Nuclear and elementary particle physics: 431 [VDP]ParticlesDark matter (Astronomy)Confidence levelbaryon: dark matterUpsilon(10020): rare decayBranching fractionMatèria fosca (Astronomia)QuarkParticle physicsDark matterFOS: Physical sciencesLambda: pair productionelectron positron: annihilationPartícules (Matèria)NOPhysics and Astronomy (all)BABAR experiment0103 physical sciencesAtomic physicUpsilon(10355): branching ratio010306 general physicsdetectorBranching fractiondark matter: massState (functional analysis)stabilitySLAC PEP StorHEPA-stableBaBarElementary Particles and FieldsHigh Energy Physics::Experimentlimitsexperimental results
researchProduct

ϒ suppression at forward rapidity in Pb–Pb collisions at √sNN = 5.02 TeV

2019

Inclusive ϒ(1S) and ϒ(2S) production have been measured in Pb–Pb collisions at the centre-of-mass energy per nucleon–nucleon pair √sNN = 5.02 TeV, using the ALICE detector at the CERN LHC. The ϒ mesons are reconstructed in the centre-of-mass rapidity interval 2.5 < y < 4 and in the transversemomentum range pT < 15 GeV/c, via their decays to muon pairs. In this Letter, we present results on the inclusive ϒ(1S) nuclear modification factor RAA as a function of collision centrality, transverse momentum and rapidity. The ϒ(1S) and ϒ(2S) RAA, integrated over the centrality range 0–90%, are 0.37± 0.02(stat) ± 0.03(syst) and 0.10 ± 0.04(stat) ± 0.02(syst), respectively, leading to a ratio Rϒ(2S) AA…

Nuclear and High Energy PhysicsPb–Pb collisionsHigh Energy Physics::Experimentupsilon mesonshiukkasfysiikkaNuclear Experiment
researchProduct