Nuclear Experiment
- [1] arXiv:2405.09577 [pdf, ps, html, other]
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Title: Controlling $^{229}$Th isomeric state population in a VUV transparent crystalTakahiro Hiraki, Koichi Okai, Michael Bartokos, Kjeld Beeks, Hiroyuki Fujimoto, Yuta Fukunaga, Hiromitsu Haba, Yoshitaka Kasamatsu, Shinji Kitao, Adrian Leitner, Takahiko Masuda, Guan Ming, Nobumoto Nagasawa, Ryoichiro Ogake, Martin Pimon, Martin Pressler, Noboru Sasao, Fabian Schaden, Thorsten Schumm, Makoto Seto, Yudai Shigekawa, Koutaro Shimizu, Tomas Sikorsky, Kenji Tamasaku, Sayuri Takatori, Tsukasa Watanabe, Atsushi Yamaguchi, Yoshitaka Yoda, Akihiro Yoshimi, Koji YoshimuraComments: 14 pages with 8 figures and 2 tablesSubjects: Nuclear Experiment (nucl-ex); Atomic Physics (physics.atom-ph)
The radioisotope Th-229 is renowned for its extraordinarily low-energy, long-lived nuclear first-excited state. This isomeric state can be excited by VUV lasers and the transition from the ground state has been proposed as a reference transition for ultra-precise nuclear clocks. Such nuclear clocks will find multiple applications, ranging from fundamental physics studies to practical implementations. Recent investigations extracted valuable constraints on the nuclear transition energy and lifetime, populating the isomer in stochastic nuclear decay of U-233 or Ac-229.
However, to assess the feasibility and performance of the (solid-state) nuclear clock concept, time-controlled excitation and depopulation of the $^{229}$Th isomer together with time-resolved monitoring of the radiative decay are imperative.
Here we report the population of the $^{229}$Th isomeric state through resonant X-ray pumping and detection of the radiative decay in a VUV transparent $^{229}$Th-doped CaF$_2$ crystal. The decay half-life is measured to $447\pm 25$ s, with a transition wavelength of $148.18 \pm 0.42$ nm and a radiative decay fraction consistent with unity. Furthermore, we report a new ``X-ray quenching'' effect which allows to de-populate the isomer on demand and effectively reduce the half-life by at least a factor 50. Such controlled quenching can be used to significantly speed up the interrogation cycle in future nuclear clock schemes.
Our results show that full control over the $^{229}$Th nuclear isomer population can be achieved in a crystal environment. In particular, non-radiative decay processes that might lead to a broadening of the isomer transition linewidth are negligible, paving the way for the development of a compact and robust solid-state nuclear clock. Further studies are needed to reveal the underlying physical mechanism of the X-ray quenching effect. - [2] arXiv:2405.10258 [pdf, ps, html, other]
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Title: The 3He(\vec n,p)3H parity-conserving asymmetryM. Viviani, S. Baeßler, L. Barrón-Palos, N. Birge, J.D. Bowman, J. Calarco, V. Cianciolo, C.E. Coppola, C.B. Crawford, G. Dodson, N. Fomin, I. Garishvili, M.T. Gericke, L. Girlanda, G.L. Greene, G.M. Hale, J. Hamblen, C. Hayes, E. B. Iverson, M.L. Kabir, A. Kievsky, L.E. Marcucci, M. McCrea, E. Plemons, A. Ramírez-Morales, P.E. Mueller, I. Novikov, S.I. Penttila, E.M. Scott, J. Watts, C. WickershamComments: 8 pages, 3 figuresSubjects: Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
Recently, the n$^3$He collaboration reported a measurement of the parity-violating (PV) proton directional asymmetry $A_{\mathrm {PV}} = (1.55\pm 0.97~\mathrm {(st\ at)} \pm 0.24~\mathrm {(sys)})\times 10^{-8}$ in the capture reaction of ${}^3$He$(\vec {n},{\mathrm p}){}^3$H at meV incident neutron energies. The result increased the limited inventory of precisely measured and calculable PV observables in few-body systems required to further understand the structure of hadronic weak interaction. In this letter, we report the experimental and theoretical investigation of a parity conserving (PC) asymmetry $A_{\mathrm {PC}}$ in the same reaction (the first ever measured PC observable at meV neutron energies). As a result of S- and P-wave mixing in the reaction, the $A_{\mathrm {PC}}$ is inversely proportional to the neutron wavelength $\lambda$. The experimental value is $(\lambda\times A_{\mathrm {PC}})\equiv\beta= (-1.97 \pm 0.28~\mathrm{(stat)}\pm 0.12~\mathrm{(sys)}) \times 10^{-6}$ Amstrongs. We present results for a theoretical analysis of this reaction by solving the four-body scattering problem within the hyperspherical harmonic method. We find that in the ${}^3$He$(\vec {n},{\mathrm p}){}^3$H reaction, $A_{\mathrm {PC}}$ depends critically on the energy and width of the close $0^-$ resonant state of ${}^4$He, resulting in a large sensitivity to the spin-orbit components of the nucleon-nucleon force and even to the three-nucleon force. The analysis of the accurately measured $A_{\mathrm {PC}}$ and $A_{\mathrm {PV}}$ using the same few-body theoretical models gives essential information needed to interpret the PV asymmetry in the ${}^3$He$(\vec {n}, {\mathrm p}){}^3$H reaction.
New submissions for Friday, 17 May 2024 (showing 2 of 2 entries )
- [3] arXiv:2405.09807 (cross-list from nucl-th) [pdf, ps, html, other]
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Title: Three-body forces and Efimov physics in nuclei and atomsComments: 28 pages, 11 figuresSubjects: Nuclear Theory (nucl-th); Quantum Gases (cond-mat.quant-gas); Nuclear Experiment (nucl-ex)
This review article presents historical developments and recent advances in our understanding on the three-body forces and Efimov physics, from an interdisciplinary viewpoint encompassing nuclear physics and cold atoms. Theoretical attempts to elucidate the three-body force with the chiral effective field theory are explained, followed by an overview of experiments aimed at observing signatures of the nuclear three-body force. Some recent experimental and theoretical works in the field of cold atoms devoted to measuring and engineering three-body forces among atoms are also presented. As a phenomenon arising from the three-body effect, Efimov physics in both cold atoms and nuclear systems is reviewed.
- [4] arXiv:2405.09971 (cross-list from nucl-th) [pdf, ps, html, other]
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Title: A study of the fine-structure constant dependence of radiative capture in Halo-EFTComments: 17 pages, 14 figuresSubjects: Nuclear Theory (nucl-th); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th); Nuclear Experiment (nucl-ex)
We study the fine-structure constant dependence of the rates of some selected radiative capture reactions within the framework of so-called Halo Effective Field Theory in order to assess the adequacy of some assumptions made on the Coulomb penetrability. We find that this dependence deviates from that implied by a parameterization of the cross sections of this effect via a simple penetration factor. Some features of this fine-structure dependence are discussed, in particular its potential impact on the abundances of the light elements in primordial nucleosynthesis.
- [5] arXiv:2405.10278 (cross-list from nucl-th) [pdf, ps, html, other]
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Title: Locating the critical point for the hadron to quark-gluon plasma phase transition from finite-size scaling of proton cumulants in heavy-ion collisionsSubjects: Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
We perform a finite-size scaling analysis of net-proton number cumulants in Au+Au collisions at center-of-mass energies between $\sqrt{s_{\rm{NN}}} = 2.4$ GeV and 54.4 GeV to search for evidence of a critical point in the QCD phase diagram. In our analysis, we use both susceptibility and Binder cumulants which we extract from the second and fourth moments of the net-proton number distributions. We take measurements in different rapidity bin widths, corresponding to different subvolumes of the system, as probes of different length scales. We use model simulations to verify the applicability of this approach, then apply it to data and find evidence for a critical point near the baryon chemical potential of $\mu_{B} \approx 625$ MeV and temperature of $T \approx 140$ MeV. The Binder cumulants, also analyzed in varying rapidity bin widths, provide complementary evidence for a critical point in a similar region. This is the first analysis of experimental data to locate the critical point in a range consistent with theoretical predictions.
Cross submissions for Friday, 17 May 2024 (showing 3 of 3 entries )
- [6] arXiv:2311.09985 (replaced) [pdf, ps, html, other]
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Title: Measurement of forward charged hadron flow harmonics in peripheral PbPb collisions at $\sqrt{s_{NN}}=5.02$ TeV with the LHCb detectorLHCb collaboration: R. Aaij, A.S.W. Abdelmotteleb, C. Abellan Beteta, F. Abudinén, T. Ackernley, B. Adeva, M. Adinolfi, P. Adlarson, C. Agapopoulou, C.A. Aidala, Z. Ajaltouni, S. Akar, K. Akiba, P. Albicocco, J. Albrecht, F. Alessio, M. Alexander, A. Alfonso Albero, Z. Aliouche, P. Alvarez Cartelle, R. Amalric, S. Amato, J.L. Amey, Y. Amhis, L. An, L. Anderlini, M. Andersson, A. Andreianov, P. Andreola, M. Andreotti, D. Andreou, A. Anelli, D. Ao, F. Archilli, M. Argenton, S. Arguedas Cuendis, A. Artamonov, M. Artuso, E. Aslanides, M. Atzeni, B. Audurier, D. Bacher, I. Bachiller Perea, S. Bachmann, M. Bachmayer, J.J. Back, A. Bailly-reyre, P. Baladron Rodriguez, V. Balagura, W. Baldini, J. Baptista de Souza Leite, M. Barbetti, I. R. Barbosa, R.J. Barlow, S. Barsuk, W. Barter, M. Bartolini, F. Baryshnikov, J.M. Basels, G. Bassi, B. Batsukh, A. Battig, A. Bay, A. Beck, M. Becker, F. Bedeschi, I.B. Bediaga, A. Beiter, S. Belin, V. Bellee, K. Belous, I. Belov, I. Belyaev, G. Benane, G. Bencivenni, E. Ben-Haim, A. Berezhnoy, R. Bernet, S. Bernet Andres, H.C. Bernstein, C. Bertella, A. Bertolin, C. Betancourt, F. Betti, J. Bex, Ia. Bezshyiko, J. Bhom, M.S. Bieker, N.V. Biesuz, P. Billoir, A. Biolchini, M. Birch, F.C.R. Bishop, A. Bitadze, A. Bizzeti, M.P. Blago, T. Blake, F. Blanc, J.E. BlankComments: All figures and tables, along with any supplementary material and additional information, are available at this https URL (LHCb public pages)Journal-ref: Phys. Rev. C 109 (2024) 054908Subjects: Nuclear Experiment (nucl-ex); High Energy Physics - Experiment (hep-ex)
Flow harmonic coefficients, $v_n$, which are the key to studying the hydrodynamics of the quark-gluon plasma (QGP) created in heavy-ion collisions, have been measured in various collision systems and kinematic regions and using various particle species. The study of flow harmonics in a wide pseudorapidity range is particularly valuable to understand the temperature dependence of the shear viscosity to entropy density ratio of the QGP. This paper presents the first LHCb results of the second- and the third-order flow harmonic coefficients of charged hadrons as a function of transverse momentum in the forward region, corresponding to pseudorapidities between 2.0 and 4.9, using the data collected from PbPb collisions in 2018 at a center-of-mass energy of $5.02$ TeV. The coefficients measured using the two-particle angular correlation analysis method are smaller than the central-pseudorapidity measurements at ALICE and ATLAS from the same collision system but share similar features.
- [7] arXiv:2312.06572 (replaced) [pdf, ps, html, other]
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Title: Evidence for an excess of charged over neutral $K$ meson production in high-energy collisions of atomic nucleiNA61/SHINE Collaboration: H. Adhikary, P. Adrich, K.K. Allison, N. Amin, E.V. Andronov, I.-C. Arsene, M. Bajda, Y. Balkova, D. Battaglia, A. Bazgir, S. Bhosale, M. Bielewicz, A. Blondel, M. Bogomilov, Y. Bondar, A. Brandin, W. Brylinski, J. Brzychczyk, M. Buryakov, A.F. Camino, M. Cirkovic, M. Csanád, J. Cybowska, T. Czopowicz, C. Dalmazzone, N. Davis, A. Dmitriev, P. von Doetinchem, W. Dominik, J. Dumarchez, R. Engel, G.A. Feofilov, L. Fields, Z. Fodor, M. Friend, M. Gazdzicki, O. Golosov, V. Golovatyuk, M. Golubeva, K. Grebieszkow, F. Guber, S.N. Igolkin, S. Ilieva, A. Ivashkin, A. Izvestnyy, N. Kargin, N. Karpushkin, E. Kashirin, M. Kiełbowicz, V.A. Kireyeu, R. Kolesnikov, D. Kolev, Y. Koshio, V.N. Kovalenko, S. Kowalski, B. Kozłowski, A. Krasnoperov, W. Kucewicz, M. Kuchowicz, M. Kuich, A. Kurepin, A. László, M. Lewicki, G. Lykasov, V.V. Lyubushkin, M. Mackowiak-Pawłowska, Z. Majka, A. Makhnev, B. Maksiak, A.I. Malakhov, A. Marcinek, A.D. Marino, H.-J. Mathes, T. Matulewicz, V. Matveev, G.L. Melkumov, A. Merzlaya, Ł. Mik, S. Morozov, Y. Nagai, T. Nakadaira, M. Naskret, S. Nishimori, A. Olivier, V. Ozvenchuk, O. Panova, V. Paolone, O. Petukhov, I. Pidhurskyi, R. Płaneta, P. Podlaski, B.A. Popov, B. Pórfy, D.S. Prokhorova, D. Pszczel, S. Puławski, J. Puzovic, R. Renfordt, L. RenComments: The paper includes updates based on the final results of $K^+$ and $K^-$ yields published in Eur. Phys. J.C 84 (2024) 4, 416Subjects: Nuclear Experiment (nucl-ex); High Energy Physics - Experiment (hep-ex)
Collisions of atomic nuclei at relativistic velocities produce new particles, predominantly mesons containing one valence quark and one valence anti-quark. These particles are produced in strong interactions, which preserve an approximate symmetry between up ($u$) and down ($d$) quarks. In the case of $K$ meson production, if this symmetry were exact, it would result in equal numbers of charged ($K^+$ and $K^-$) and neutral ($K^0$ and $\overline K^0$) mesons in the final state. In this Letter, we report a measurement of the relative abundance of charged over neutral $K$ meson production in collisions of argon and scandium nuclei at a center-of-mass energy of 11.9 GeV per nucleon pair. We find that production of $\mathit{K^+}$ and $\mathit{K^-}$ mesons at mid-rapidity is $(18.4\pm 6.1)\%$ higher than that of the neutral $K$ mesons. The origin of this unexpected excess remains to be elucidated.
- [8] arXiv:2206.14441 (replaced) [pdf, ps, html, other]
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Title: Quantum Chromodynamics Resolution of the ATOMKI Anomaly in ${\rm {^4He}}$ Nuclear TransitionsComments: Experimental signatures of the model added, 9 pages, 3 figures, comments welcomeSubjects: High Energy Physics - Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
Observations of anomalous angular correlations in electron-positron pairs produced from excited states of $^{4}$He, $^{8}$Be and $^{12}$C nuclei have been suggested as due to the creation and subsequent decay of a new light particle of mass $\sim$17 MeV. In this work, we investigate the possibility that the source of the observed signals is a set of new excitation channels created by the 12-quark hidden-color Fock state within the ${\rm {^4He}}$ nuclear wavefunction dubbed the "hexadiquark." We calculate the invariant $e^+e^-$ mass spectrum for the electromagnetic transition from a new excitation of $^{4}$He, estimating its differential and total decay width. We find that we can fit the shape of the anomalous signal with the QCD Fock state at excitation energy $\rm E^{*} = 17.9 \pm 1$ MeV and a Gaussian form factor for the electromagnetic decay. We address the physical issues with the fit parameters using properties of the hexadiquark state, in particular the three weakly repulsive $\rm 6_C$ interactions of $\rm SU(3)_C$ between diquark pairs. Experimental tests of our model are described in detail. In light of this work, we emphasize the need for independent experimental confirmation or refutation of the ATOMKI results as well as dedicated experiments to search for the proposed new excitations of ${\rm ^4He}$ and other $\alpha$-cluster nuclei.
- [9] arXiv:2405.06839 (replaced) [pdf, ps, html, other]
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Title: Results from the CsI Calorimeter onboard the 2023 ComPair Balloon FlightDaniel Shy, Richard S. Woolf, Clio Sleator, Bernard Phlips, J. Eric Grove, Eric A. Wulf, Mary Johnson-Rambert, Mitch Davis, Emily Kong, Thomas Caligiure, A. Wilder Crosier, Aleksey Bolotnikov, Nicholas Cannady, Gabriella A. Carini, Regina Caputo, Jack Fried, Priyarshini Ghosh, Sean Griffin, Elizabeth Hays, Sven Herrmann, Carolyn Kierans, Nicholas Kirschner, Iker Liceaga-Indart, Zachary Metzler, Julie McEnery, John Mitchell, A. A. Moiseev, Lucas Parker, Alfred Dellapenna, Jeremy S. Perkins, Makoto Sasaki, Adam J. Schoenwald, Lucas D. Smith, Janeth Valverde, Sambid Wasti, Anna ZajczykSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Nuclear Experiment (nucl-ex)
The ComPair gamma-ray telescope is a technology demonstrator for a future gamma-ray telescope called the All-sky Medium Energy Gamma-ray Observatory (AMEGO). The instrument is composed of four subsystems, a double-sided silicon strip detector, a virtual Frisch grid CdZnTe calorimeter, a CsI:Tl based calorimeter, and an anti-coincidence detector (ACD). The CsI calorimeter's goal is to measure the position and energy deposited from high-energy events. To demonstrate the technological readiness, the calorimeter has flown onboard a NASA scientific balloon as part of the GRAPE-ComPair mission and accumulated around 3 hours of float time at an altitude of 40 km. During the flight, the CsI calorimeter observed background radiation, Regener-Pfotzer Maximum, and several gamma-ray activation lines originating from aluminum.