Searches for Pentaquark Baryons at BaBar

This paper presents the results of inclusive searches for the strange pentaquark states $\Theta^+(1540)$, $\Xi_5^{--}(1860)$ and $\Xi_5(1860)^{0}$ as well as the anti-charm pentaquark state $\Theta_c(3099)^{0}$ in a dataset of 123.4 fb$^{-1}$ collected on and 40$$MeV below the $\Upsilon(4S)$ resonance by the BABAR detector at the $e^+e^-$ PEPII storage rings. No evidence for the pentaquark states is found and upper limits on the rate of $\Theta^+(1540)$ and $\Xi_5^{--}(1860)$ production in $e^+e^-$ annihilation are obtained.Comment: 4 pages, 2 postscript figues, contributed to the Proceedings of HADRON0

A Study of B+->p pbar K+ and a Search for a Theta*++ Pentaquark Candidate in B Decay

A study of the decay B+->ppbarK+ is performed using 81fb-1 of data collected at the Upsilon(4S) with the BaBar detector at PEP-II. The branching fraction of B+->ppbarK+ is measured to be (6.7+/-0.9+/-0.6)x10^-6. An upper limit on the branching fraction of B+->Theta*++pbar, where Theta*++ is a narrow state decaying to pK+, is set to be 1.5x10^-7 for 1.43<m(Theta*++)<1.85GeV/c^2 at 90% confidence level. All results are preliminary.Comment: 3 pages, 1 figure, presented at DPF 2004, Annual Meeting of the Division of Particles and Fields(DPF) of the American Physical Society(APS) at Riverside, CA, August 26-31, 200

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements