SLD reconstructed mini-DSTs from the 1996-1997 SLC runs

This record contains the reconstructed mini-Data Summary Tapes (mini-DSTs) from the SLAC Large Detector (SLD) experiment at the SLAC Linear Collider, covering the 1996-1997 data-taking periods. The events are made available in two formats: the native binary "jazelle" columnar format used by the SLD reconstruction software, and a derived Apache Parquet translation that is convenient for modern columnar analysis tools (PyArrow, pandas, awkward, polars, ...). The two formats contain identical physics content; the Parquet version is the one most users will want.

Contents

38 mini-DST files split across five run blocks (qf1065-qf1066 from 1997, qf1070 from 1997, qf1076 and qf1083 from 1996, and qf1087 from 1997). After translation and reading via the jazelle Python package, the dataset contains 279,505 reconstructed events. The centre-of-mass energy is at the Z pole (sqrt(s) ~= 91.2 GeV) and the electron beam was longitudinally polarised with average magnitude |P_e| ~= 0.74. Per-event polarisation values are recorded in the PHBM bank.

Bank families

Reconstruction outputs are organised into "bank families", each describing one detector subsystem or one stage of the reconstruction chain. The banks present in this release:

IEVENTH -- event header (run/event ID, trigger mask, timestamp). PHBM -- beam information (beam energy, beam polarisation magnitude and sign, interaction-point position and uncertainty). PHPSUM -- inclusive list of reconstructed physics particles (4-momentum, charge, origin coordinates). PHPOINT -- master pointer bank linking each PHPSUM entry to its associated track (PHCHRG) and/or calorimeter cluster (PHKLUS), enabling per-particle access to detector- level quantities. PHCHRG -- raw charged-track helix parameters from the Central Drift Chamber (CDC) and Vertex Detector (VXD). PHKLUS -- calorimeter clusters from the Liquid Argon Calorimeter (LAC). PHWIC -- muon hits in the Warm Iron Calorimeter (WIC).

The mini-DSTs are the reduced-format event records produced by the SLD reconstruction; they contain enough information for typical physics analyses (event shapes, electroweak asymmetries, jet clustering) but not the full raw detector data.

Further documentation on the jazelle file format can be found in the README of the jazelle package GitHub repository (see "Related identifiers" for a link).

Sample statistics

Total events: 279,505 Hadronic Z -> qq: 156,214 (default 2000 A_LR selection) Leptonic (any): 23,035 (default 2001 leptonic selection) Z -> e+e-: 6,631 Z -> mu+mu-: 5,551 Z -> tau+tau-: 6,765 Mean charged particles / event: 12.8 Avg |P_e|: ~0.74

Files in this record

sld_minidsts_jazelle_1996_1997.tar.gz 38 files in the native binary jazelle format. This is a faithful preservation copy of the original SLD reconstruction output. The bank definitions necessary to interpret the format are documented in the jazelle Python reader (see "Related identifiers"). Most users should prefer the Parquet release unless they specifically need the binary format.

sld_minidsts_parquet_1996_1997.tar.gz 38 Parquet files (one per source mini-DST) carrying the same events translated into Apache Parquet. Each file is a single Awkward record array with a top-level field per bank family.

Reading the data

The Parquet files can be read directly with any Parquet-aware library:

import jazelle as jz; data = jz.from_parquet("qf1065....parquet"); data.PHPSUM.fields; >> ['px', 'py', 'pz', 'charge', ...]

The jazelle binary files require the jazelle Python package (see "Related identifiers" for a link). The companion sld_resurrect package wraps both formats and provides helpers for particle 4-vector construction, event-shape observables, and the published SLD event selections (A_LR, leptonic asymmetries, ...).

Provenance

The mini-DSTs were produced by the SLD reconstruction software during the 1996-1997 SLC runs. The jazelle release here is a faithful copy of those preserved files, and the Parquet release is the deterministic output of running the jazelle Python package on each one (no information is lost in the translation; field names follow the bank-internal labels).