Thu·Sep 12, 2024Thursday·September 12, 2024

1. 01*

   Groomed Event Shapes at HERA and the sPHENIX TPC

   Henry T. Klest🇺🇸

   This thesis summarizes the work of the author in two directions, both aimed at the study of quantum chromodynamics (QCD). The first topic presented is a measurement of groomed event shapes using archived data collected by the H1 experiment at HERA. The data analysis methods and physics implications of the results are discussed, with the goal of improving the theoretical description of the hadronic final state in electron-hadron collisions before the construction of the Electron-Ion Collider (EIC). The second topic concerns the sPHENIX experiment, which is now installed at the Relativistic Heavy Ion Collider (RHIC). The sPHENIX physics program and apparatus will be discussed, along with a description of each of the subdetectors. Special attention will be dedicated to the operating principles, design, and construction of the time projection chamber (TPC).

   nucl-exhep-exhep-ph0 citations
2. 02*

   Bottom quark energy loss and hadronization with B${}^{+}$ and B${}_{\mathrm{s}}^0$ nuclear modification factors using pp and PbPb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV

   CMS Collaboration

   The production cross sections of B${}_{\mathrm{s}}^0$ and B${}^{+}$ mesons are reported in proton-proton (pp) collisions recorded by the CMS experiment at the CERN LHC with a center-of-mass energy of 5.02 TeV. The data sample corresponds to an integrated luminosity of 302 pb${}^{-1}$. The cross sections are based on measurements of the B${}_{\mathrm{s}}^0$ $\to$ J/$\psi ({\mu }^{+}{\mu }^{-})\varphi$(1020) (K${}^{+}$K${}^{-}$) and B${}^{+}$ $\to$ J/$\psi ({\mu }^{+}{\mu }^{-})$K${}^{+}$ decay channels. Results are presented in the transverse momentum ($p_{\mathrm{T}}$) range 7-50 GeV/$c$ and the rapidity interval $|y|$ $<$ 2.4 for the B mesons. The measured $p_{\mathrm{T}}$-differential cross sections of B${}^{+}$ and B${}_{\mathrm{s}}^0$ in pp collisions are well described by fixed-order plus next-to-leading logarithm perturbative quantum chromodynamics calculations. Using previous PbPb collision measurements at the same nucleon-nucleon center-of-mass energy, the nuclear modification factors, $R_{\mathrm{AA}}$, of the B mesons are determined. For $p_{\mathrm{T}}$ $<$ 10 GeV/$c$, both mesons are found to be suppressed in PbPb collisions (with $R_{\mathrm{AA}}$ values significantly below unity), with less suppression observed for the B${}_{\mathrm{s}}^0$ mesons. In this $p_{\mathrm{T}}$ range, the $R_{\mathrm{AA}}$ values for the B${}^{+}$ mesons are consistent with those for inclusive charged hadrons and D${}^0$ mesons. Below 10 GeV/$c$, both B${}^{+}$ and B${}_{\mathrm{s}}^0$ are found to be less suppressed than either inclusive charged hadrons or D${}^0$ mesons, with the B${}_{\mathrm{s}}^0$ $R_{\mathrm{AA}}$ value consistent with unity. The $R_{\mathrm{AA}}$ values found for the B${}^{+}$ and B${}_{\mathrm{s}}^0$ are compared to theoretical calculations, providing constraints on the mechanism of bottom quark energy loss and hadronization in the quark-gluon plasma, the hot and dense matter created in ultrarelativistic heavy ion collisions.

   nucl-exhep-exJHEP(2025)·10 citations
3. 03*

   ${}^{61}$Cr as a Doorway to the N = 40 Island of Inversion

   L. Lalanne🇧🇪 · M. Athanasakis-Kaklamanakis🇨🇭 · D. D. Dao🇫🇷 · Á. Koszorús🇧🇪 · Y. C. Liu🇨🇳 · R. Mancheva🇧🇪 · F. Nowacki🇫🇷 · J. Reilly🇬🇧 · C. Bernerd🇨🇭 · K. Chrysalidis🇨🇭 · T. E. Cocolios🇧🇪 · R. P. de Groote🇧🇪 and 15 other authors

   This paper reports on the measurement of the ground-state spin and nuclear magnetic dipole moment of ${}^{61}$Cr. The radioactive ion beam was produced at the CERN-ISOLDE facility and was probed using high-resolution resonance ionization laser spectroscopy with the CRIS apparatus. The present ground-state spin measurement $I=\frac{1}{2}$, differing from the previously adopted $I=(\frac{5}{2})$, has significant consequences on the interpretation of existing beta decay data and nuclear structure in the region. The structure and shape of ${}^{61}$Cr is interpreted with state-of-the-art Large-Scale Shell Model and Discrete-Non-Orthogonal Shell Model calculations. From the measured magnetic dipole moment $\mu {(}^{61}$Cr$)=+0.539(7){\mu }_N$ and the theoretical findings, its configuration is understood to be driven by 2 particle - 2 hole neutron excitations with an unpaired $1p_{1/2}$ neutron. This establishes the western border of the $N=40$ Island Of Inversion (IoI), characterized by 4 particle - 4 hole neutron components. We discuss the shape evolution along the Cr isotopic chain as a quantum phase transition at the entrance of the $N=40$ IoI.

   nucl-exnucl-thPRC(2025)·3 citations
4. 04*

   Unified and optimal frame choice for generalized parton distributions

   Jian-Wei Qiu🇺🇸 · Nobuo Sato🇺🇸 · Zhite Yu🇺🇸

   Reconstructing the internal three-dimensional quark and gluon structures of hadrons through generalized parton distributions (GPDs) from hard exclusive scattering processes is one of the most challenging tasks in nuclear and particle physics. In this paper, we introduce a new optimized reference frame that, for the first time, enables a unified view of all the reactions sensitive to GPDs and facilitates the interpretation of a variety of phase-space patterns that were previously hardly accessible and interpretable. Similarly to how the heliocentric description advanced our understanding of the solar system and gravitation, our new frame centers around a quasireal state, allows for a consistent separation of physical scales, and reveals a novel quantum interference mechanism.

   ↳ hep-phhep-exhep-latnucl-ex+1PRD(2025)·5 citations
5. 05*

   Neutron skin and its effects in heavy-ion collisions

   Meng-Qi Ding🇨🇳 · De-Qing Fang🇨🇳 · Yu-Gang Ma🇨🇳

   Neutron skin is an exotic phenomena in unstable nuclei. The various effects in nuclear reactions caused by the neutron skin and also its relation with the properties of nuclear structure are reviewed in this article. Based on numerous studies with theoretical models, strong correlations have been found between the neutron skin thickness and neutron removal cross section, neutron/proton yield ratio, t/\ch{^3He} yield ratio, neutron-proton momentum difference, isoscaling parameter, photon production, reaction cross sections for neutron induced reactions, charge-changing cross sections difference of mirror nuclei, astrophysical $S$-factor, and other quantities in nuclear reactions induced by neutron-rich nuclei. Moreover, the relationships between neutron skin thickness and some properties of nuclear structure, such as $\alpha$-cluster formation, $\alpha$ decay, nuclear surface, nuclear temperature, and proton radii difference of mirror nuclei, have also been investigated. It also has been shown that the neutron skin plays a crucial role in relativistic heavy-ion collisions. Experimentally, an unstable nucleus with neutron skin can be generated by radioactive nuclear beam facilities, and the thickness of neutron skin could be extracted by measuring the sensitive probes, which further helps giving stringent constraints on the equation of state of asymmetric nuclear matter and properties of neutron stars.

   ↳ nucl-thnucl-exNucl.Sci.Tech.(2024)·29 citations
6. 06*

   Unraveling the Effects of Cluster Transfer-Induced Breakups on ${}^{12}$C Fragmentation in Hadron Therapy

   Arunima Dev T V · Anagha P. K · Midhun C.V · M.M Musthafa · Vafiya Thaslim T.T · Shaima Akbar · Swapna B · Nicemon Thomas · Antony Joseph · S. Ganesan

   The capability of standard Geant4 PhysicsLists to address the fragmentation of ${}^{12}$C${-}^{12}$C was assessed through a comparative analysis with experimental cross sections reported by Divay et al. and Dudouet et al. The standard PhysicsLists were found to be inadequate in explaining the fragmentation systematics. To address this limitation, the breakup component of fragmentation was systematically integrated into the standard PhysicsList, which successfully replicated the differential and double differential cross sections for $\alpha$ production. This breakup component was modeled using fresco CDCC-CRC calculations. This novel physics process was then incorporated into the Geant4 framework, facilitating the calculation of dose distributions in water and tissue. The application of this method demonstrated a precise reproduction of the dose deposited at the Bragg peak region, corroborating the experimental data from Liedner et al., thereby enhancing the accurate visibility of dose tailing.

   ↳ physics.med-phnucl-exnucl-thJ.Subatomic Part.Cosmol.(2026)·2 citations
7. 07*

   Minimizing Selection Bias in Inclusive Jets in Heavy-Ion Collisions with Energy Correlators

   Carlota Andres🇺🇸 · Jack Holguin🇬🇧 · Raghav Kunnawalkam Elayavalli🇺🇸 · Jussi Viinikainen🇺🇸

   The first-ever measurement of energy correlators within inclusive jets produced in heavy-ion collisions, revealed by the CMS Collaboration, shows a clear enhancement at large angles relative to the proton-proton (p-p) baseline. However, interpreting this enhancement is complicated due to selection bias from energy loss, which also distorts the energy correlator heavy-ion to p-p ratio in the hadronization region, hindering our understanding of parton/hadron dynamics in a colored medium. In this Letter, we introduce a new ratio of energy correlator observables that removes the leading effects of selection bias from the two-point energy correlator spectrum (E2C). Pythia and Herwig simulations show that the impact of selection bias in the E2C is reduced by an order of magnitude, while sensitivity to any other medium modifications is retained. This quantity can be obtained directly from the experimental measurements presented by CMS, as illustrated in the accompanying note.

   ↳ hep-phhep-exnucl-exnucl-thPRL(2025)·30 citations
8. 08*

   Minimizing Selection Bias in Inclusive Jets in Heavy-Ion Collisions with Energy Correlators -- arXiv note

   Carlota Andres🇺🇸 · Jack Holguin🇬🇧

   This note serves as a companion to a Letter, where we introduce a new energy correlator-based observable designed to minimize the impact of selection bias due to energy loss in inclusive jets in heavy-ion collisions. Here, we apply the method outlined in the Letter to the first-ever measurement of energy correlators in heavy-ion collisions, recently released by the CMS Collaboration.

   ↳ hep-phhep-exnucl-exnucl-th9 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.