Tue·Feb 27, 2024Tuesday·February 27, 2024

1. 01*

   MoEDAL search in the CMS beam pipe for magnetic monopoles produced via the Schwinger effect

   B. Acharya🇮🇹 · J. Alexandre🇬🇧 · S.C. Behera🇺🇸 · P. Benes🇨🇿 · B. Bergmann🇨🇿 · S. Bertolucci🇮🇹 · A. Bevan🇬🇧 · R. Brancaccio🇮🇹 · H. Branzas🇷🇴 · P. Burian🇨🇿 · M. Campbell🇨🇭 · S. Cecchini🇮🇹 and 55 other authors

   We report on a search for magnetic monopoles (MMs) produced in ultraperipheral Pb--Pb collisions during Run-1 of the LHC. The beam pipe surrounding the interaction region of the CMS experiment was exposed to 184.07 \textmu b${}^{-1}$ of Pb--Pb collisions at 2.76 TeV center-of-mass energy per collision in December 2011, before being removed in 2013. It was scanned by the MoEDAL experiment using a SQUID magnetometer to search for trapped MMs. No MM signal was observed. The two distinctive features of this search are the use of a trapping volume very close to the collision point and ultra-high magnetic fields generated during the heavy-ion run that could produce MMs via the Schwinger effect. These two advantages allowed setting the first reliable, world-leading mass limits on MMs with high magnetic charge. In particular, the established limits are the strongest available in the range between 2 and 45 Dirac units, excluding MMs with masses of up to 80 GeV at 95\% confidence level.

   nucl-exhep-exPRL(2024)·34 citations
2. 02*

   Existance of octupole correlation in 116Sn

   Prithwijita Ray🇺🇸 · H. Pai🇷🇴 · S. Chakraborty🇺🇸 · A. Mukherjee · S. Rajbanshi🇮🇳 · Sajad Ali🇮🇳 · G. Gangopadhyay · S. Bhattacharyya🇮🇳 · G. Mukherjee · C. Bhattacharya🇮🇳 · Soumik Bhattacharya🇮🇳 · R. Banik🇮🇳 and 7 other authors

   The negative parity states in 116Sn have been investigated in terms of octupole correlation. The same is probed by using the Indian National Gamma Array (INGA) facility at Variable Energy Cyclotron Centre, Kolkata using the reaction, 114Cd({\alpha},2n) 116Sn at 34 MeV energy. Three new {\gamma}-transitions relevant to the present investigation are reported and the spin-parities of the associated levels are assigned based on the DCO-ratios and polarisation measurements. The interband transitions between the positive parity ground band and the negative parity band are newly observed and the corresponding extracted ratio of transition probability, B(E1)/B(E2) indicated the existence of octupole correlation in these nuclei. The enhanced transition rates for E1 and E3 transitions between these opposite parity bands and corroboration of soft octupole deformation ultimately aid the onset of octupole excitation in this isotope.

   nucl-ex0 citations
3. 03*

   Cluster structure of 3$\alpha$+p states in ${}^{13}$N

   J. Bishop🇺🇸 · G.V. Rogachev🇺🇸 · S. Ahn🇰🇷 · M. Barbui🇺🇸 · S.M. Cha🇰🇷 · E. Harris🇺🇸 · C. Hunt🇺🇸 · C.H. Kim🇰🇷 · D. Kim🇰🇷 · S.H. Kim🇰🇷 · E. Koshchiy🇺🇸 · Z. Luo🇺🇸 and 7 other authors

   Background: Cluster states in ${}^{13}$N are extremely difficult to measure due to the unavailability of ${}^9$B+$\alpha$ elastic scattering data. Purpose: Using $\beta$-delayed charged-particle spectroscopy of ${}^{13}$O, clustered states in ${}^{13}$N can be populated and measured in the 3$\alpha$+p decay channel. Method: One-at-a-time implantation/decay of ${}^{13}$O was performed with the Texas Active Target Time Projection Chamber (TexAT TPC). 149 $\beta 3\alpha p$ decay events were observed and the excitation function in ${}^{13}$N reconstructed. Results: Four previously unknown $\alpha$-decaying excited states were observed in ${}^{13}$N at an excitation energy of 11.3 MeV, 12.4 MeV, 13.1 MeV and 13.7 MeV decaying via the 3$\alpha$+p channel. Conclusion: These states are seen to have a [${}^9\mathrm{B}(g.s)⨂\alpha$/ $p{+}^{12}\mathrm{C}(0_2^{+})$], [${}^9\mathrm{B}({\frac{1}{2}}^{+})⨂\alpha$], [${}^9\mathrm{B}({\frac{5}{2}}^{+})⨂\alpha$] and [${}^9\mathrm{B}({\frac{5}{2}}^{+})⨂\alpha$] structure respectively. A previously-seen state at 11.8 MeV was also determined to have a [$p{+}^{12}\mathrm{C}(g.s.)$/ $p{+}^{12}\mathrm{C}(0_2^{+})$] structure. The overall magnitude of the clustering is not able to be extracted however due to the lack of a total width measurement. Clustered states in ${}^{13}$N (with unknown magnitude) seem to persist from the addition of a proton to the highly $\alpha$-clustered ${}^{12}$C. Evidence of the ${\frac{1}{2}}^{+}$ state in ${}^9$B was also seen to be populated by decays from ${}^{13}$N${}^{\star }$.

   nucl-exPRC(2024)·9 citations
4. 04*

   In-beam test results of an RPC-based module for position-sensitive neutron detectors with timing readout

   G. Canezin · L. M. S. Margato · A. Morozov🇷🇺 · A. Blanco🇵🇹 · J. Saraiva🇵🇹 · L. Lopes🇧🇷 · P. Fonte🇵🇹 · Chung Chuan Lai🇸🇪 · Per-Olof Svensson🇸🇪 · G. Markaj🇨🇭 · Florian M. Piegsa🇨🇭

   Recently we have proposed a new concept of a thermal neutron detector based on resistive plate chambers and 10B4C solid neutron converters, enabling to readout with high resolution in both the 3D position of neutron capture and the neutron time of flight (ToF). In this paper, we report the results of the first beam tests conducted with a new neutron RPC detection module, coupled to the position readout units of a new design. The main focus is on the measurements of the neutron ToF and identification of the converter layer where the neutron is captured, giving the position along the beam direction.

   ↳ physics.ins-detnucl-exJINST(2024)·0 citations
5. 05*

   Ab initio description of monopole resonances in light- and medium-mass nuclei: II. Ab initio PGCM calculations in ${}^{46}$Ti, ${}^{28}$Si and ${}^{24}$Mg

   Andrea Porro🇩🇪 · Thomas Duguet🇫🇷 · Jean-Paul Ebran🇫🇷 · Mikael Frosini🇫🇷 · Robert Roth🇩🇪 · Vittorio Somà🇫🇷

   Giant resonances (GRs) are a striking manifestation of collective motions in atomic nuclei. The present paper is the second in a series of four dedicated to the use of the projected generator coordinate method (PGCM) for the ab initio determination of the isoscalar giant monopole resonance (GMR) in closed- and open-shell mid-mass nuclei. While the first paper was dedicated to quantifying various uncertainty sources, the present paper focuses on the first applications to three doubly-open shell nuclei, namely ${}^{46}$Ti, ${}^{28}$Si and ${}^{24}$Mg. In particular, the goal is to investigate from an ab initio standpoint (i) the coupling of the GMR with the giant quadrupole resonance (GQR) in intrinsically-deformed nuclei, (ii) the possible impact of shape coexistence and shape mixing on the GMR, (iii) the GMR based on shape isomers and (iv) the impact of anharmonic effects on the monopole response. The latter is studied by comparing PGCM results to those obtained via the quasi-particle random phase approximation (QRPA), the traditional many-body approach to giant resonances, performed in a consistent setting. Eventually, PGCM results for sd-shell nuclei are in excellent agreement with experimental data, which is attributed to the capacity of the PGCM to capture the important fragmentation of the monopole response in light, intrinsically-deformed systems. Still, the comparison to data in ${}^{28}$Si and ${}^{24}$Mg illustrates the challenge (and the potential benefit) of extracting unambiguous experimental information.

   ↳ nucl-thnucl-exEPJA(2024)·19 citations
6. 06*

   Improved Limits on $n\to n^{\prime }$ Transformation from the Spallation Neutron Source

   Francisco M. Gonzalez🇺🇸 · Cary Rock🇺🇸 · Leah J. Broussard🇺🇸 · Lisa DeBeer-Schmitt🇺🇸 · Matthew J. Frost🇺🇸 · Lawrence Heilbronn🇺🇸 · Erik B. Iverson🇺🇸 · Yuri Kamyshkov🇺🇸 · Michael Kline🇺🇸 · David Milstead🇸🇪 · Devyn Powers🇺🇸 · James Rogers🇺🇸 · Valentina Santoro🇸🇪 · Shaun Vavra🇺🇸

   Conversions between neutrons $n$ and Dark Matter candidate sterile neutrons $n^{\prime }$ have been proposed as a mechanism for Baryon Number $\mathcal{B}$ violation. In the case that there is a small mass difference $\Delta m$ between the $n$ and the $n^{\prime }$ states, oscillations can be induced by compensating for $\Delta m$ with a magnetic field. A search for such neutron oscillations was performed at the Spallation Neutron Source by looking for anomalous neutron transmission through a strongly absorbing cadmium wafer inside of a $6.6$~T magnet. The approach described here saw no regenerated neutrons above background, which provides an improved limit for neutron - sterile neutrons transformations for a range of $\Delta m$ between $0.1$~neV and $1000$~neV.

   ↳ hep-exnucl-exPRD(2024)·10 citations
7. 07*

   Achieving a Near-Ideal Silicon Crystal Neutron Interferometer using Sub-Micron Fabrication Techniques

   M. G. Huber🇨🇦 · I. Taminiau · D. G. Cory · B. Heacock🇺🇸 · D. Sarenac · R. Valdillez🇺🇸 · D. A. Pushin🇨🇦

   Perfect-crystal neutron interferometry which is analogous to Mach-Zehnder interferometry, uses Bragg diffraction to form interfering neutron paths. The measured phase shifts can be used to probe many types of interactions whether it be nuclear, electromagnetic, gravitational, or topological in nature. For a perfect-crystal interferometer to preserve coherence, the crystal must possess a high degree of dimensional tolerance as well as being relatively defect-free with minimal internal stresses. In the past, perfect-crystal neutron interferometers have been produced by a two step process. First, a resin diamond wheel would be used to remove excess material and shape the interferometer. Afterword, the crystal would be etched in order to remove surface defects and elevate strains. This process has had limitations in terms of repeatability and in maximizing the final contrast, or fringe visibility, of the interferometer. We have tested various fabrication and post-fabrication techniques on a single perfect-crystal neutron interferometer and measured the interferometer's performance at each step. Here we report a robust, repeatable non-etching fabrication process with high final contrast. For the interferometer used in this work, we achieved contrasts of greater than 90% several separate times and ultimately finished with an interferometer that has 92% contrast and a uniform phase distribution.

   ↳ physics.ins-detnucl-exPRResearch(2024)·3 citations
8. 08*

   Ultra-High precision Compton polarimetry at 2 GeV

   A. Zec🇺🇸 · S. Premathilake🇺🇸 · J. C. Cornejo🇺🇸 · M. M. Dalton🇺🇸 · C. Gal🇺🇸 · D. Gaskell🇺🇸 · M. Gericke🇨🇦 · I. Halilovic🇨🇦 · H. Liu🇨🇳 · J. Mammei🇨🇦 · R. Michaels🇺🇸 · C. Palatchi🇺🇸 and 4 other authors

   We report a high precision measurement of electron beam polarization using Compton polarimetry. The measurement was made in experimental Hall A at Jefferson Lab during the CREX experiment in 2020. A total uncertainty of dP/P=0.36% was achieved detecting the back-scattered photons from the Compton scattering process. This is the highest accuracy in a measurement of electron beam polarization using Compton scattering ever reported, surpassing the ground-breaking measurement from the SLAC Large Detector (SLD) Compton polarimeter. Such uncertainty reaches the level required for the future flagship measurements to be made by the MOLLER and SoLID experiments.

   ↳ physics.ins-detnucl-exPRC(2024)·8 citations
9. 09*

   Measurement of beauty-quark production in pp collisions at $\sqrt{s}=13$ TeV via non-prompt D mesons

   ALICE Collaboration

   The $p_{\mathrm{T}}$-differential production cross sections of non-prompt ${\mathrm{D}}^0$, ${\mathrm{D}}^{+}$, and ${\mathrm{D}}_{\mathrm{s}}^{+}$ mesons originating from beauty-hadron decays are measured in proton$-$proton collisions at a centre-of-mass energy $\sqrt{s}=13$ TeV. The measurements are performed at midrapidity, $|y|<0.5$, with the data sample collected by ALICE from 2016 to 2018. The results are in agreement with predictions from several perturbative QCD calculations. The fragmentation fraction of beauty quarks to strange mesons divided by the one to non-strange mesons, $f_{\mathrm{s}}/(f_{\mathrm{u}}+f_{\mathrm{d}})$, is found to be $0.114\pm 0.016(stat.)\pm 0.006(syst.)\pm 0.003(\mathrm{BR})\pm 0.003(extrap.)$. This value is compatible with previous measurements at lower centre-of-mass energies and in different collision systems in agreement with the assumption of universality of fragmentation functions. In addition, the dependence of the non-prompt D meson production on the centre-of-mass energy is investigated by comparing the results obtained at $\sqrt{s}=5.02$ and 13 TeV, showing a hardening of the non-prompt D-meson $p_{\mathrm{T}}$-differential production cross section at higher $\sqrt{s}$. Finally, the $\mathrm{b}\overline{\mathrm{b}}$ production cross section per unit of rapidity at midrapidity is calculated from the non-prompt ${\mathrm{D}}^0$, ${\mathrm{D}}^{+}$, ${\mathrm{D}}_{\mathrm{s}}^{+}$, and ${\Lambda }_{\mathrm{c}}^{+}$ hadron measurements, obtaining $\mathrm{d}\sigma /\mathrm{d}y=75.2\pm 3.2(stat.)\pm 5.2(syst.{)}_{-3.2}^{+12.3}(extrap.)\mu \mathrm{b}.$

   ↳ hep-exnucl-exJHEP(2024)·21 citations
10. 10*

    Shell-model study of $\log ft$ values for ${}^{139,140,141}$Ba $\to$ ${}^{139,140,141}$La transitions

    Shweta Sharma🇮🇳 · Praveen C. Srivastava🇮🇳

    In the present work, beta-decay properties such as $\log ft$ values and half-lives have been systematically studied corresponding to Ba isotopes using large-scale shell-model calculations. An extensive comparison of beta decay results corresponding to ${}^{141}$Ba$\to$ ${}^{141}$La using shell-model calculations is made with the recently available experimental data. In addition, we have also calculated the nuclear and beta decay properties corresponding to ${}^{139}$Ba$\to$ ${}^{139}$La and ${}^{140}$Ba$\to$ ${}^{140}$La transitions. The model-space considered here is $Z=50-82$ and $N=82-126$ with ${}^{132}$Sn core, and the interaction employed here is jj56pnb interaction. The beta decay results using shell-model calculations for all the mentioned isotopes are compared with the available experimental data. This is the first theoretical interpretation corresponding to recent experimental data.

    ↳ nucl-thnucl-exNPA(2024)·1 citation
11. 11*

    Hexadecapole deformation of ${}^{238}$U from relativistic heavy-ion collisions using a nonlinear response coefficient

    Hao-jie Xu🇨🇳 · Jie Zhao🇨🇳 · Fuqiang Wang🇺🇸

    The hexadecapole deformation (${\beta }_4$) of the ${}^{238}$U nucleus has not been determined because its effect is overwhelmed by those from the nucleus' large quadrupole deformation (${\beta }_2$) in nuclear electric transition measurements. In this Letter, we identify the nonlinear response of the hexadecapole anisotropy to ellipticity in relativistic ${}^{238}$U+ ${}^{238}$U collisions that is solely sensitive to ${\beta }_4$ and insensitive to ${\beta }_2$. We demonstrate this by state-of-the-art hydrodynamic calculations and discuss the prospects of discovering the ${\beta }_4$ of ${}^{238}$U in heavy-ion data at the Relativistic Heavy Ion Collider.

    ↳ nucl-thnucl-exPRL(2024)·36 citations
12. 12*

    Medium-induced photon bremsstrahlung in neutrino-nucleus, antineutrino-nucleus, and electron-nucleus scattering from multiple QED interactions

    Oleksandr Tomalak🇺🇸 · Ivan Vitev🇺🇸

    Interactions of charged leptons with nuclei and the naive tree-level kinematics of these processes are affected by radiation of photons induced by the QED nuclear medium. We evaluate cross-section modifications at leading orders of the number of correlated interactions inside the nucleus, known as the opacity expansion. We derive results for soft and collinear types of the bremsstrahlung at the first three orders in opacity and generalize them to higher orders. We present the leading in opacity energy spectra of soft and collinear photons and radiative energy loss inside the nucleus for experiments with lepton kinematics in the GeV energy range. At leading power of the Glauber soft-collinear effective field theory, the soft radiation is further resummed to all orders both in opacity and in the electromagnetic coupling constant. We find that the soft and collinear medium-induced radiation is vacuumlike, and additional corrections are power suppressed. Despite the negligible modification to the induced photon spectra, the nuclear medium-induced radiation sizably affects the broadening of charged leptons in the direction orthogonal to their propagation.

    ↳ hep-phhep-exnucl-exnucl-thPRD(2024)·8 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.