Thu·Mar 27, 2025Thursday·March 27, 2025

1. 01*

   Observation of nuclear modification of energy-energy correlators inside jets in heavy ion collisions

   CMS Collaboration

   Energy-energy correlators are constructed by averaging the number of charged particle pairs within jets, weighted by the product of their transverse momenta, as a function of the angular separation of the particles within a pair. They are sensitive to a multitude of perturbative and nonperturbative quantum chromodynamics phenomena in high-energy particle collisions. Using lead-lead data recorded with the CMS detector, energy-energy correlators inside high transverse momentum jets are measured in heavy ion collisions for the first time. The data are obtained at a nucleon-nucleon center-of-mass energy of 5.02 TeV and correspond to an integrated luminosity of 1.70 nb${}^{-1}$. A similar analysis is done for proton-proton collisions at the same center-of-mass energy to establish a reference. The ratio of lead-lead to proton-proton energy-energy correlators reveals significant jet substructure modifications in the quark-gluon plasma. The results are compared to different models that incorporate either color coherence or medium response effects, where the two effects predict similar substructure modifications.

   nucl-exhep-exPLB(2025)·49 citations
2. 02*

   Nuclear recoil detection with color centers in bulk lithium fluoride

   Gabriela A. Araujo🇨🇭 · Laura Baudis🇨🇭 · Nathaniel Bowden🇺🇸 · Jordan Chapman🇺🇸 · Anna Erickson · Mariano Guerrero Perez · Adam A. Hecht · Samuel C. Hedges🇺🇸 · Patrick Huber🇺🇸 · Vsevolod Ivanov · Igor Jovanovic🇺🇸 · Giti A. Khodaparast and 10 other authors

   We present initial results on nuclear recoil detection based on the fluorescence of color centers created by nuclear recoils in lithium fluoride. We use gamma rays, fast and thermal neutrons, and study the difference in responses they induce, showing that this type of detector is rather insensitive to gamma rays. We use light-sheet fluorescence microscopy to image nuclear recoil tracks from fast and thermal neutron interactions deep inside a cubic-centimeter sized crystal and demonstrate automated feature extraction in three dimensions using machine learning tools. The number, size, and topology of the events agree with expectations based on simulations with TRIM. These results constitute the first step towards 10-1000g scale detectors with single-event sensitivity for applications such as the detection of dark matter particles, reactor neutrinos, and neutrons.

   nucl-exhep-exhep-phphysics.ins-detEPJC(2026)·8 citations
3. 03*

   Exploiting $\nu$-dependence of projected energy correlators in HICs

   Ankita Budhraja🇳🇱 · Balbeer Singh🇺🇸

   We extend the recently derived factorization formula for energy-energy correlators to study the analytic structure of general $\nu$-point projected energy correlators in heavy ion collisions. The $\nu$-point projected energy correlators (or, $\nu$-correlators) are an analytically continued family of the integer $N$-point projected energy correlators, which probe correlations between $N$ final-state particles. By tracking the largest separation ($\chi$) between the $N$ particles, in vacuum, their structure is closely related to the DGLAP splitting functions and exhibits a classical scaling behavior $\sim 1/\chi$ which is modified by resummation through the anomalous dimensions. We show that, in a thermal medium, the $\nu$-correlators display non-trivial angular scaling already at the leading order in perturbation theory. We find that for non-integer values, particularly $\nu <1$, medium-induced jet function is enhanced compared to $\nu >1$. This is particularly manifested in the ratios of $\nu$-correlators with respect to the two-point energy correlator which encode an intrinsic angular information for $\nu <1$ when compared to large $\nu$ values. Moreover, for small-$\nu$ values, the $\nu$-correlators appear to saturate at $\nu =0.01$. We further confirm our leading-order numerical computations against simulated events from JEWEL for the parton level production cross-section. Finally, we qualitatively discuss the effect of BFKL resummation for various values of $\nu$.

   ↳ hep-phnucl-exnucl-thPLB(2026)·10 citations
4. 04*

   Development and Characterization of a High-Resolution and High-Sensitivity Collinear Resonance Ionization Spectroscopy Setup

   H. R. Hu🇨🇳 · Y. F. Guo🇨🇳 · X. F. Yang🇨🇳 · Z. Yan🇨🇳 · W. C. Mei🇨🇳 · S. J. Chen🇨🇳 · Y. S. Liu🇨🇳 · P. Zhang🇨🇳 · S. W. Bai🇨🇳 · D. Y. Chen🇨🇳 · Y. C. Liu🇨🇳 · S. J. Wang🇨🇳 and 5 other authors

   With the recent implementation of a radio-frequency quadrupole (RFQ) cooler-buncher and a multi-step laser resonance ionization technique, our previously developed collinear laser spectroscopy setup has been successfully upgraded into a fully functional collinear resonance ionization spectroscopy system. The new system was fully characterized using a bunched ion beam at 30~keV, during which hyperfine structure spectra of ${}^{85,87}$Rb isotopes were measured. An overall efficiency exceeding 1:200 (one resonant ion detected for every 200 ions after the RFQ cooler-buncher) was achieved while maintaining a spectral resolution of 100 MHz. Under these conditions, the extracted hyperfine structure parameters and isotope shift for ${}^{85,87}$Rb show excellent agreement with the literature values. These results demonstrate the system's capability to perform high-resolution and high-sensitivity laser spectroscopy of neutron-rich Rb isotopes, which are expected to be produced at the Beijing Radioactive Ion-beam Facility at a rate of approximately 100 particles per second.

   ↳ physics.ins-detnucl-exphysics.acc-phSci.Bull.(2025)·6 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.