Version 2.4.0 August 14, 2023

New Physics Modeling:

• Kr83m models and defaults revised: closer to first principles and less confusing. (Matthew Szydagis, LZ / UAlbany)
• Skewness modeling off by default (in execNEST, not in NEST.cpp), but skew fits still on in order to capture the intrinsic skewness

New Code Features:

• Standard detector now LZ SR1 not LUX Run03 any longer, and secondary analysis header filed created (..._G2) with carefully selected defaults to cover both LZ SR1 and XENONnT SR0 without warnings or errors.
• GetYieldERWeighted function no longer has fixed weights: both the energy- and field-dependent weights are now adjustable
• New bash script tracker.sh in examples subfolder for simulating muons, with many comments, features, and reminders, and a smart interplay with the verbosity flag.
• To better aid in mimicking a PLR, rootNEST leakage calculation now allows NR acceptance other than 50%, Feldman-Cousin mean versus median glitch solved, plus many other rootNEST fixes for limit setting
• Xenoscope latest results on the dependences of longitudinal diffusion and electron drift velocity on E-field incorporated within new +/- 1 sigma alternative models structure.
• LArSoft Integration, with errors addressed in LArNEST examples by adding in the missing dx parameter to the FullCalculation function (Nick Carrara, DUNE / UC Davis)
• Replaced sprintf() function w/ snprintf() everywhere so new Macs stop complaining

Miscellaneous Bug Fixes:

• rootNEST now ignores bins with outlier log(S2/S1) values when calculating reduced chi^2 for GoF (Kian Trengove, LZ / UCLA)
• Repaired glitch where Nph/keV and Ne-/keV for muons were infinite, and NaN true muon energy solved.
• Exponential energy spectrum feature in execNEST restored.
• All long long int versus int64 and long long int versus long int warnings eliminated.
• Ion decays from primaries with zero kinetic energy now trigger the creation of lineages in Geant4 (Jason Brodsky, nEXO / LLNL)
• Inconsistencies in CMake Configuration Instructions made consistent (Lukas Gerritzen, MEG / Tokyo)

(NESTv2.4.0beta overlay in cyan and green)

Version 2.3.12 January 27, 2023

• Fano factor for all ER (betas and gammas) now a free parameter (combined-E scale) with a default of 1 and no energy or field dependence by default any more
• Allowing reverse compatibility with the older more complicated Fano factor model (energy and field dependent) for LZ SR1 especially, by entering a negative value.
• Recombination fluctuations low-field, baseline amplitude lowered from 0.05 to 0.046 everywhere, to better match the ER band widths in LZ SR1 & XENONnT SR0.
• All free-param m’s (in the sigmoids) in the GregR beta ER model are now settable by the end user. Use -1’s to get the defaults
• A bug fix within the Liquid Argon modeling: alpha-particle light yields increased after double-counting of quenching was addressed (Kate K., MEPhI)

Version 2.3.11 Sept. 8, 2022 (XENONnT ER paper & LZ NR (WIMP) paper better matched)

New Physics Modeling:

• NR and ER band widths reduced to more closely match (still not perfect) both XENONnT for ER (https://arxiv.org/abs/2207.11330) and LZ for NR and ER (https://arxiv.org/abs/2207.03764); matching historical data like LUX Run03 will now require increased widths using linear noise terms (Greg Rischbieter, LZ/UMich)

New Code Features:

• Added detector for XENONnT’s first dark-matter-search run, SR0 (Min Zhong, XENON/UCSD)
• Overhaul of LArNEST especially for fluctuations modeling (Nick Carrara, DUNE/UCDavis)

Miscellaneous Bug Fixes:

• Work function properly sourced if a free parameter (loopNEST) for use in combined-scale energy reconstruction formula (Kirsten McMichael, nEXO/RPI)

Version 2.3.10 Aug 13 ’22 (LZ SR1 params; generic leakage script)

New Physics Modeling:

• SE mean size based on loop not EL yield x g1_gas; loop size can be changed from one location now (Matthew Szydagis, LZ/UAlbany)

New Code Features:

• Bash script added for rapidly calculating the ER leakage fraction as a function of the drfit electric field (Matthew)
• Updated the S1 and S2 linear noise warnings for >100% instead of >10% to catch people confusing % and fraction (Greg Rischbieter, LZ/UMich)
• Added detector file for LZ’s 1st WIMP-search run (SR1) and removed virtual declaration of functions in LZ_SR1.hh (Greg R.)

Miscellaneous Bug Fixes:

• Removed glitch whereby loopNEST was stuck on tritium as source, and provided more instructions (Kirsten McMichael, nEXO/RPI)

Version 2.3.9 July 7, 2022 (modifiable skew, new halo mod #s, eff script)

New Physics Modeling:

• Skewness can be turned off and on now for ER just like for NR. For on -> old model or fixed (Quentin Riffard, LZ/LBNL)
• Older beta model is default for gaseous Xenon, a better fit to old world data at the keV scale (Eric Church, DUNE/PNNL)
• New dark matter halo model defaults, bringing NEST up to date on WIMP and Sun v's (Baxter et al., arXiv:2105.00599)

New Code Features (Matthew Szydagis, LZ/UAlbany):

• Verbosity level is not a Boolean any more but an integer, easily allowing different amounts
• A bash script is included in the examples subfolder now for studying efficiency vs. E
• rootNEST no longer quits out if efficiency fit bad but asks user what they want to do instead
• rootNEST now allows for custom upper limits on the number of signal evts, for PLR mimicry

Miscellaneous Bug Fixes:

• Fluctuations adjust for difference in width from truncated Gaussians for PE not just mean
• Complaint that position resolution too poor does not activate until above S2 (top) of 40 PE
• In the dE/dx-based model the minimum LET is now 1.0 MeV/cm not 0 to avoid weirdness

Version 2.3.8 June 11, 2022

Code Quality and/or Miscellaneous Bug Fixes:

• Geant4 code variable name consistency with rest of NEST, and relativistic energy in G4 (Paola Ferrario, PETALO/Basque Foundation for Science)
• More complete installation directions for Geant4 within NEST (Eric Church, DUNE/PNNL)
• Errors are always reported as NEST first in numerator, so e.g. '+' means NEST is too high in mean or width, while '-' means too low.

New Features and New Physics (Matthew Szydagis, LZ/UAlbany):

• Gaussians are now explicitly one of three possible implementations: normal, no negative but 0 pileup allowed, and re-sampled truncation: rare corner cases repaired as a result. Band means impacted due to changed S2 photo-electron normalization but only by O(0.1%). Very minor changes to the chi^2 validations with the LUX Run03 3H and D-D bands.
• S2 longitudinal diffusion model updated based on issue #155 to be higher at high fields, but also higher at low fields (a very different shape). Data in literature remain contradictory, so the Boyle model is preserved as an option, which does match LUX Run02 (surface) better.
• The MIP model has a default Fano-like factor of 1.00 now for total quanta, but F_s = 200 for scintillation versus ionization for the anti-correlation "slosh"

Version 2.3.7 May 9, 2022 (flexible ER widths; LArSoft compatibility)

Code Quality and/or Miscellaneous Bug Fixes:

• Keep e- momentum unit vector in Geant4 (Paola Ferrario, PETALO/Basque Foundation for Science)
• Parameters for fluctuations are now free for the beta model, with free-param vectors named more sensibly (Greg Rischbieter, LZ/UAlbany)
• LArSoft-compatible code added for neutrino experiments (Nick Carrara, DUNE/UCDavis)
• Annoying warning for negative NR yield in GXe removed (Matthew Szydagis, LZ/UAlbany)

New Physics:

• NONE! (same validation table as v2.3.6 release)

Version 2.3.6 Apr 11, 2022 (vertical cosmics; Geant field in any direction)

Code Quality and/or Miscellaneous Bug Fixes:

• Geant4.9.11 & C++17 compatibility achieved (Paola Ferrario, PETALO/Basque Foundation for Science)
• Multiple scatter code warning addressed: unused variable (Greg Rischbieter, LZ/UAlbany)

New Physics:

• Perfectly vertical MIP tracks now work, and use latest beta model (Greg Rischbieter, LZ/UAlbany)
• Field in G4 in any direction not just vertical but e.g. radial OK, ala (n)EXO and PETALO (Paola Ferrario)

Version 2.3.5 Feb 9, 2022 (dE/dx yields func for muons + loopNEST, >=2 scatters exec)

Code Quality and/or Miscellaneous Bug Fixes:

• random exponential smarter sampling for small ranges especially for Kr83m times (Scott Kravitz, LZ/LBNL)
• D-D energy spectrum user-settable, serving as example for any NR calibrations (Greg Rischbieter, LZ/UAlbany)
• New truncated Gauss option, w/ truncation at 0 in 1st usage to solve S2 corner case (Scott Kravitz, LZ/LBNL)

New Physics:
(Matthew Szydagis, LZ/UAlbany and Greg Rischbieter)

• dE/dx-based yield code moved (execNEST->NEST.cpp) for accessibility. Muons, MIPs, LIPs; random positions
• Initial or average dE/dx allowed, and use of ESTAR or custom power law, with variation around a mean dE/dx
• loopNEST for ER restored, with 1st-principles mod TIB model of recombination parameters for sustainability
• New multiple scatter tool allows for creation of 2+ ER-like/NR-like scatters, or mixed for inelastic, Migdal, etc.

Version 2.3.0 Nov 11, 2021 (e-EE, binom rand, Pb-206, Kr83m)

New Physics:

• Carried over from v2.3 beta: A new binomial random number generator (C++ default library), e- EE models, beta model with new yields and fluctuations, non-beta-ER (XELDA).
• New beta model is default regardless of E-field, but old one is still accessible
• ER model (betas and gammas weighted) is its own function, callable
• Pb-206 ion coming off wall from alpha decay has correct Ly and Qy versus field (Thomas-Imel box model for recomb)
• The electron extraction efficiency model now includes “optimistic” high e- EE Aprile/PandaX fits (activatable with EPS_GAS negative)

Code Quality and/or Miscellaneous Bug Fixes:

• C++11 => 17 default, README updated with all new versioning requirements, but old gcc and cmake versions requested to allow backwards-compatibility with nestpy. std::clamp still doesn’t work, so similar function written by hand
• 1.1 => 1.08 for increasing Qy to match new Zurich W-value measurement, but with new more logical variable names both deep in code and in detector file for user, and with one factor universal in NEST.cpp; general variable renaming for greater clarity
• Numerous cosmetic and aesthetic changes to code, including unused variable removal, while spacing and tabbing made Google clang-format (with shell script for that now included with NEST), if/else Mac dangle warning addressed
• Kr83m yields same but code overhauled to allow min versus max time separation flexibility and easier data comparison, with bug squashed where wrong error message got replayed
• NEST is now ~30% faster, cf. v2.2.4, at least when using gcc 7+, despite the new binomial fluctuation function!

Human Credits:

• Chris, Sophia, Kirsten, Nishat, Greg R., Robert James, Jacob McLaughlin, anyone else I (Matthew) forgot to thank. LZ + XENON + nEXO.