Methods for a blind analysis of isobar data collected by the STAR collaboration

In 2018,the STAR collaboration collected data from^(96)_(44)Ru+^(96)_(44)Ru and^(96)_(40)Zr+^(96)_(40)Zr at√^(S)NN=200 Ge V to search for the presence of the chiral magnetic effect in collisions of nuclei.The isobar collision species alternated frequently between 9644 Ru+^(96)_(44)Ru and^(96)_(40)Zr+^(96)_(40)Zr.In order to conduct blind analyses of studies related to the chiral magnetic effect in these isobar data,STAR developed a three-step blind analysis procedure.Analysts are initially provided a"reference sample"of data,comprised of a mix of events from the two species,the order of which respects time-dependent changes in run conditions.After tuning analysis codes and performing time-dependent quality assurance on the reference sample,analysts are provided a species-blind sample suitable for calculating efficiencies and corrections for individual≈30-min data-taking runs.For this sample,species-specific information is disguised,but individual output files contain data from a single isobar species.Only run-by-run corrections and code alteration subsequent to these corrections are allowed at this stage.Following these modifications,the"frozen"code is passed over the fully un-blind data,completing the blind analysis.As a check of the feasibility of the blind analysis procedure,analysts completed a"mock data challenge,"analyzing data from Au+Au collisions at√^(S)NN=27 Ge V,collected in 2018.The Au+Au data were prepared in the same manner intended for the isobar blind data.The details of the blind analysis procedure and results from the mock data challenge are presented.

E-ANA-TUM AND THE RULER OF ARAWA1

1. Introduction In the inscriptions of E-ana-tum, ruler of Lagas, listing his victories over various cities, there is a four-line long passage that describes E-ana-tum’s defeat over the city called Arawa:2 (1)su-nir URU×Aki-ka, ensi2-be2 3, saη-ba mu-DU, aga3-kar2 !(SE3)4 be2-seg10 The translations of this grammatically difficult passage vary greatly;there seems to be no agreement either about its exact meaning or about its grammatical analysis.

Forecast of cosmological constraints with type Ia supernovae from the Chinese Space Station Telescope

The 2-m aperture Chinese Space Station Telescope(CSST),which observes at wavelengths ranging from 255 to 1000 nm,is expected to start science operations in 2024.An ultra-deep field observation program covering approximately 10 deg2is proposed with supernovae(SNe) and other transients as one of its primary science drivers.This paper presents the simulated detection results of type Ⅰa supernovae(SNe Ⅰa) and explores the impact of new datasets on the determinations of cosmological parameters.The simulated observations are conducted with an exposure time of 150 s and cadences of 10,20,and 30 d.The survey mode covering a total of 80 observations but with a random cadence in the range of 4 to 14 d is also explored.Our simulation results indicate that the CSST can detect up to ~1800 SNe la at z <1.3.The simulated SNe la are then used to constrain the cosmological parameters.The constraint on can be improved by 37.5% using the 10-d cadence sample in comparison with the Pantheon sample.A deeper measurement simulation with a 300 s exposure time together with the Pantheon sample improves the current constraints on Ωmby 58.3% and ω by 47.7%.Taking future lager sets of nearby SN Ⅰa sample form ground-based surveys(i.e.,N~3400) into consideration,the constraints on ω can be improved by 59.1%.The CSST ultra-deep field observation program is expected to discover large amounts of SNe la over a broad redshift span and enhance our understanding of the nature of dark energy.