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Population pumping of vibrational and rotational quantum states in the triatomic hydrogen ion observed by electron-beam-assisted high-resolution spectroscopy

Marleen Maxton ¹, Lukas Berger ¹, Jonas Bechtel ¹, Lucia Enzmann ¹, Manfred Grieser ¹, Florian Grussie ¹, Jannis Himmelsbach ¹, Leonard W. Isberner ^2,1, Viviane C. Schmidt ^1,* et al.

Deepak Sharma ^3,1, Andreas Wolf ¹, Aigars Znotins ¹, Xavier Urbain ⁴, Oldřich Novotný ¹, and Holger Kreckel ^1,†

¹Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
²Columbia Astrophysics Laboratory, Columbia University, New York, New York 10027, USA
³Faculty of Physics, Weizmann Institute of Science, Rehovot 76100, Israel
⁴Institute of Condensed Matter and Nanosciences, Université Catholique de Louvain, 1348 Louvain-la-Neuve, Belgium

^*Present address: Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Innsbruck, Austria.
^†Contact author: holger.kreckel@mpi-hd.mpg.de

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Phys. Rev. Research 8, 043045 – Published 14 October, 2026

DOI: https://doi.org/10.1103/w9q1-yk99

Abstract

We present a technique to observe the optical manipulation of individual quantum states of $H_{3}^{+}$ ions stored inside a heavy-ion storage ring, where the excitation is detected by electron-beam-assisted action spectroscopy. The transitions addressed here are chosen to enable multicolor spectroscopy of states far above the energetic barrier, where this molecule—with a triangular ground state—can sample linear geometries. This region of the spectrum has so far been inaccessible due to extremely weak direct transition strengths from the ground vibrational level. Our experiments pave the way for spectroscopy of the simplest polyatomic molecule in a previously unexplored energetic territory, which would benchmark theoretical data crucial for the understanding of this fundamental molecular system. Our results also demonstrate laser pumping to vibrationally and rotationally excited states of $H_{3}^{+}$ , gaining model-dependent access to their relative dissociative electron recombination rates.

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References (100)

I. Manai, R. Horchani, H. Lignier, P. Pillet, D. Comparat, A. Fioretti, and M. Allegrini, Rovibrational cooling of molecules by optical pumping, Phys. Rev. Lett. 109, 183001 (2012).
G. Quéméner and P. S. Julienne, Ultracold molecules under control!, Chem. Rev. 112, 4949 (2012).
J. M. Hutson, Ultracold chemistry, Science 327, 788 (2010).
N. J. Fitch and M. R. Tarbutt, Laser-cooled molecules, Adv. At. Mol. Opt. Phys. 70, 157 (2021).
I. Kozyryev, L. Baum, K. Matsuda, B. L. Augenbraun, L. Anderegg, A. P. Sedlack, and J. M. Doyle, Sisyphus laser cooling of a polyatomic molecule, Phys. Rev. Lett. 118, 173201 (2017).
L. Baum, N. B. Vilas, C. Hallas, B. L. Augenbraun, S. Raval, D. Mitra, and J. M. Doyle, 1D magneto-optical trap of polyatomic molecules, Phys. Rev. Lett. 124, 133201 (2020).
Y. Zeng, A. Jadbabaie, A. N. Patel, P. Yu, T. C. Steimle, and N. R. Hutzler, Optical cycling in polyatomic molecules with complex hyperfine structure, Phys. Rev. A 108, 012813 (2023).
J. B. Dragan, I. O. Antonov, and B. C. Odom, Features of molecular structure beneficial for optical pumping, Phys. Rev. A 107, 033110 (2023).
M. V. Ivanov, T.-C. Jagau, G.-Z. Zhu, E. R. Hudson, and A. I. Krylov, In search of molecular ions for optical cycling: A difficult road, Phys. Chem. Chem. Phys. 22, 17075 (2020).
C.-Y. Lien, C. M. Seck, Y.-W. Lin, J. H. V. Nguyen, D. A. Tabor, and B. C. Odom, Broadband optical cooling of molecular rotors from room temperature to the ground state, Nat. Commun. 5, 4783 (2014).
P. R. Stollenwerk, B. C. Odom, D. L. Kokkin, and T. Steimle, Electronic spectroscopy of a cold ${SiO}^{+}$ sample: Implications for optical pumping, J. Mol. Spectrosc. 332, 26 (2017).
P. R. Stollenwerk, M. G. Kokish, A. G. S. de Oliveira-Filho, F. R. Ornellas, and B. C. Odom, Optical pumping of ${TeH}^{+}$ : Implications for the search for varying $m_{p} / m_{e}$ , Atoms 6, 53 (2018).
T. Schneider, B. Roth, H. Duncker, I. Ernsting, and S. Schiller, All-optical preparation of molecular ions in the rovibrational ground state, Nat. Phys. 6, 275 (2010).
S. Alighanbari, M. G. Hansen, V. I. Korobov, and S. Schiller, Rotational spectroscopy of cold and trapped molecular ions in the Lamb-Dicke regime, Nat. Phys. 14, 555 (2018).
S. Alighanbari, G. S. Giri, F. L. Constantin, V. I. Korobov, and S. Schiller, Precise test of quantum electrodynamics and determination of fundamental constants with ${HD}^{+}$ ions, Nature (London) 581, 152 (2020).
R. von Hahn, A. Becker, F. Berg, K. Blaum, C. Breitenfeldt, H. Fadil, F. Fellenberger, M. Froese, S. George, J. Göck, et al., The cryogenic storage ring CSR, Rev. Sci. Instrum. 87, 063115 (2016).
J. J. Thomson, Bakerian Lecture: Rays of positive electricity, Proc. R. Soc. Lond. A 89, 1 (1913).
T. Oka, Observation of the infrared spectrum of $H_{3}^{+}$ , Phys. Rev. Lett. 45, 531 (1980).
A. Carrington, J. Buttenshaw, and R. Kennedy, Observation of the infrared spectrum of $H_{3}^{+}$ at its dissociation limit, Mol. Phys. 45, 753 (1982).
F. Kemp, C. E. Kirk, and I. R. McNab, The infrared predissociation spectrum of $H_{3}^{+}$ , Philos. Trans. R. Soc. Lond. Ser. A 358, 2403 (2000).
E. Herbst and W. Klemperer, The formation and depletion of molecules in dense interstellar clouds, Astrophys. J. 185, 505 (1973).
W. D. Watson, The rate of formation of interstellar molecules by ion-molecule reactions, Astrophys. J. 183, L17 (1973).
T. Oka, $H_{3}^{+}$ , the ideal probe for in situ measurement of the Galactic cosmic rays, Philos. Trans. R. Soc. A 377, 20180402 (2019).
I. Labbé, P. van Dokkum, E. Nelson, R. Bezanson, K. A. Suess, J. Leja, G. Brammer, K. Whitaker, E. Mathews, M. Stefanon, and B. Wang, A population of red candidate massive galaxies ∼600 Myr after the Big Bang, Nature (London) 616, 266 (2023).
A. Ferrara, A. Pallottini, and P. Dayal, On the stunning abundance of super-early, luminous galaxies revealed by JWST, Mon. Not. R. Astron. Soc. 522, 3986 (2023).
A. Pandey, O. Dulieu, and N. Bouloufa-Maafa, An alternate pathway for $H_{2}$ formation in the early universe: A physical process to account for the presence and coevolution of the luminous galaxies and supermassive black holes at the high redshifts, arXiv:2603.08662.
M. Quack, Detailed symmetry selection rules for reactive collisions, Mol. Phys. 34, 477 (1977).
C. M. Lindsay and B. J. McCall, Comprehensive evaluation and compilation of $H_{3}^{+}$ spectroscopy, J. Mol. Spectrosc. 210, 60 (2001).
T. R. Geballe and T. Oka, Detection of $H_{3}^{+}$ in interstellar space, Nature (London) 384, 334 (1996).
B. J. McCall, T. R. Geballe, K. H. Hinkle, and T. Oka, Detection of $H_{3}^{+}$ in the diffuse interstellar medium toward Cygnus OB2 No. 12, Science 279, 1910 (1998).
P. Drossart, J.-P. Maillard, J. Caldwell, S. J. Kim, J. K. G. Watson, W. A. Majewski, J. Tennyson, S. Miller, S. K. Atreya, J. T. Clarke, J. H. Waite, and R. Wagener, Detection of $H_{3}^{+}$ on Jupiter, Nature (London) 340, 539 (1989).
T. R. Geballe, M.-F. Jagod, and T. Oka, Detection of $H_{3}^{+}$ infrared emission lines in Saturn, Astrophys. J. Lett. 408, L109 (1993).
T. R. Geballe, M. Goto, T. Usuda, T. Oka, and B. J. McCall, The interstellar medium of IRAS 08572+3915 NW: $H_{3}^{+}$ and warm high-velocity CO, Astrophys. J. 644, 907 (2006).
B. J. McCall, A. J. Huneycutt, R. J. Saykally, T. R. Geballe, N. Djuric, G. H. Dunn, J. Semaniak, O. Novotny, A. Al-Khalili, A. Ehlerding, F. Hellberg, S. Kalhori, A. Neau, R. Thomas, F. Österdahl, and M. Larsson, An enhanced cosmic-ray flux towards $ζ$ Persei inferred from a laboratory study of the $H_{3}^{+} − e^{-}$ recombination rate, Nature (London) 422, 500 (2003).
S. Miller, J. Tennyson, T. R. Geballe, and T. Stallard, Thirty years of $H_{3}^{+}$ astronomy, Rev. Mod. Phys. 92, 035003 (2020).
J. L. Gottfried, B. J. McCall, and T. Oka, Near-infrared spectroscopy of $H_{3}^{+}$ above the barrier to linearity, J. Chem. Phys. 118, 10890 (2003).
R. Röhse, W. Kutzelnigg, R. Jaquet, and W. Klopper, Potential energy surface of the $H_{3}^{+}$ ground state in the neighborhood of the minimum with microhartree accuracy and vibrational frequencies derived from it, J. Chem. Phys. 101, 2231 (1994).
J. L. Gottfried, Near-infrared spectroscopy of $H_{3}^{+}$ above the barrier to linearity, Phil. Trans. R. Soc. A 364, 2917 (2006).
S. Schlemmer, T. Kuhn, E. Lescop, and D. Gerlich, Laser excited $N_{2}^{+}$ in a 22-pole ion trap, Int. J. Mass Spectrom. 185–187, 589 (1999).
J. Mikosch, H. Kreckel, R. Wester, R. Plašil, J. Glosík, D. Gerlich, D. Schwalm, and A. Wolf, Action spectroscopy and temperature diagnostics of $H_{3}^{+}$ by chemical probing, J. Chem. Phys. 121, 11030 (2004).
H. Kreckel, D. Bing, S. Reinhardt, A. Petrignani, M. Berg, and A. Wolf, Chemical probing spectroscopy of $H_{3}^{+}$ above the barrier to linearity, J. Chem. Phys. 129, 164312 (2008).
M. Berg, A. Wolf, and A. Petrignani, Visible transitions from ground state $H_{3}^{+}$ measured with high-sensitivity action spectroscopy, Philos. Trans. R. Soc. A 370, 5028 (2012).
M. Pavanello, L. Adamowicz, A. Alijah, N. F. Zobov, I. I. Mizus, O. L. Polyansky, J. Tennyson, T. Szidarovszky, A. G. Császár, M. Berg, A. Petrignani, and A. Wolf, Precision measurements and computations of transition energies in rotationally cold triatomic hydrogen ions up to the midvisible spectral range, Phys. Rev. Lett. 108, 023002 (2012).
P. Jusko, C. Konietzko, S. Schlemmer, and O. Asvany, Frequency comb assisted measurement of fundamental transitions of cold $H_{3}^{+}, H_{2} D^{+}$ and $D_{2} H^{+}$ , J. Mol. Spectrosc. 319, 55 (2016).
M. Berblinger, E. Pollak, and C. Schlier, Bound states embedded in the continuum of $H_{3}^{+}$ , J. Chem. Phys. 88, 5643 (1988).
J. M. Gomez Llorente and E. Pollak, A classical trajectory study of the photodissociation spectrum of $H_{3}^{+}$ , J. Chem. Phys. 90, 5406 (1989).
J. R. Henderson and J. Tennyson, Calculated spectrum for near-dissociation $H_{3}^{+}$ : A first attempt, Mol. Phys. 89, 953 (1996).
G. D. Carney and R. N. Porter, $H_{3}^{+}$ : Geometry dependence of electronic properties, J. Chem. Phys. 60, 4251 (1974).
G. D. Carney and R. N. Porter, $H_{3}^{+}$ : Ab initio calculation of the vibration spectrum, J. Chem. Phys. 65, 3547 (1976).
J. Tennyson and B. T. Sutcliffe, The ab initio calculation of the vibrational-rotational spectrum of triatomic systems in the close-coupling approach, with KCN and $H_{2} Ne$ as examples, J. Chem. Phys. 77, 4061 (1982).
B. T. Sutcliffe and J. Tennyson, A generalized approach to the calculation of ro-vibrational spectra of triatomic molecules, Mol. Phys. 58, 1053 (1986).
S. Miller and J. Tennyson, First principles calculation of the molecular constants of $H_{3}^{+}, H_{2} D^{+}, D_{2} H^{+}$ , and $D_{3}^{+}$ , J. Mol. Spectrosc. 126, 183 (1987).
W. Meyer, P. Botschwina, and P. Burton, Ab initio calculation of near-equilibrium potential and multipole moment surfaces and vibrational frequencies of $H_{3}^{+}$ and its isotopomers, J. Chem. Phys. 84, 891 (1986).
L. Kao, T. Oka, S. Miller, and J. Tennyson, A table of astronomically important ro-vibrational transitions for the $H_{3}^{+}$ molecular ion, Astrophys. J. Suppl. Ser. 77, 317 (1991).
Z. Bačić and J. C. Light, Theoretical methods for rovibrational states of floppy molecules, Annu. Rev. Phys. Chem. 40, 469 (1989).
L. Neale, S. Miller, and J. Tennyson, Spectroscopic properties of the $H_{3}^{+}$ molecule: A new calculated line list, Astrophys. J. 464, 516 (1996).
B. M. Dinelli, O. L. Polyansky, and J. Tennyson, Spectroscopically determined Born-Oppenheimer and adiabatic surfaces for $H_{3}^{+}, H_{2} D^{+}, D_{2} H^{+}$ , and $D_{3}^{+}$ , J. Chem. Phys. 103, 10433 (1995).
S. C. O. Glover and D. W. Savin, Is $H_{3}^{+}$ cooling ever important in primordial gas? Mon. Not. R. Astron. Soc. 393, 911 (2009).
H. Kreckel, S. Krohn, L. Lammich, M. Lange, J. Levin, M. Scheffel, D. Schwalm, J. Tennyson, Z. Vager, R. Wester, A. Wolf, and D. Zajfman, Vibrational and rotational cooling of $H_{3}^{+}$ , Phys. Rev. A 66, 052509 (2002).
C. Hill, S. N. Yurchenko, and J. Tennyson, Temperature-dependent molecular absorption cross sections for exoplanets and other atmospheres, Icarus 226, 1673 (2013).
A. Petrignani, M. H. Berg, F. Grussie, A. Wolf, I. I. Mizus, O. L. Polyansky, J. Tennyson, N. F. Zobov, M. Pavanello, and L. Adamowicz, Communication: Visible line intensities of the triatomic hydrogen ion from experiment and theory, J. Chem. Phys. 141, 241104 (2014).
M. Pavanello, L. Adamowicz, A. Alijah, N. F. Zobov, I. I. Mizus, O. L. Polyansky, J. Tennyson, T. Szidarovszky, and A. G. Császár, Calibration-quality adiabatic potential energy surfaces for $H_{3}^{+}$ and its isotopologues, J. Chem. Phys. 136, 184303 (2012).
I. I. Mizus, A. Alijah, N. F. Zobov, L. Lodi, A. A. Kyuberis, S. N. Yurchenko, J. Tennyson, and O. L. Polyansky, ExoMol molecular line lists—XX. A comprehensive line list for $H_{3}^{+}$ , Mon. Not. R. Astron. Soc. 468, 1717 (2017).
C. A. Bowesman, I. I. Mizus, N. F. Zobov, O. L. Polyansky, J. Sarka, B. Poirier, M. Pezzella, S. N. Yurchenko, and J. Tennyson, Exomol line lists—L: High-resolution line lists of $H_{3}^{+}, H_{2} D^{+}, D_{2} H^{+}$ , and $D_{3}^{+}$ , Mon. Not. R. Astron. Soc. 519, 6333 (2023).
H. Kreckel, M. Motsch, J. Mikosch, J. Glosík, R. Plašil, S. Altevogt, V. Andrianarijaona, H. Buhr, J. Hoffmann, L. Lammich, et al., High-resolution dissociative recombination of cold $H_{3}^{+}$ and first evidence for nuclear spin effects, Phys. Rev. Lett. 95, 263201 (2005).
H. Kreckel, O. Novotný, K. N. Crabtree, H. Buhr, A. Petrignani, B. A. Tom, R. D. Thomas, M. H. Berg, D. Bing, M. Grieser, C. Krantz, M. Lestinsky, M. B. Mendes, C. Nordhorn, R. Repnow, J. Stützel, A. Wolf, and B. J. McCall, High-resolution storage-ring measurements of the dissociative recombination of $H_{3}^{+}$ using a supersonic expansion ion source, Phys. Rev. A 82, 042715 (2010).
A. Petrignani, S. Altevogt, M. H. Berg, D. Bing, M. Grieser, J. Hoffmann, B. Jordon-Thaden, C. Krantz, M. B. Mendes, O. Novotný, S. Novotny, D. A. Orlov, R. Repnow, T. Sorg, J. Stützel, A. Wolf, H. Buhr, H. Kreckel, V. Kokoouline, and C. H. Greene, Resonant structure of low-energy $H_{3}^{+}$ dissociative recombination, Phys. Rev. A 83, 032711 (2011).
A. Znotins, A. Faure, C. H. Greene, M. Grieser, F. Grussie, L. W. Isberner, Á. Kálosi, V. Kokoouline, D. Müll, D. Paul, M. Pezzella, D. W. Savin, S. Schippers, J. Tennyson, A. Wolf, O. Novotný, and H. Kreckel, Electron recombination of rotationally cold $D_{2} H^{+}$ ions, Nat. Commun. 16, 7738 (2025).
A. Znotins, A. Faure, C. H. Greene, M. Grieser, F. Grussie, L. W. Isberner, A. Kálosi, V. Kokoouline, D. Müll, D. Paul, M. Pezzella, D. W. Savin, S. Schippers, J. Tennyson, A. Wolf, O. Novotný, and H. Kreckel, Dissociative electron recombination and rotational cooling of the deuterated triatomic hydrogen ions $H_{2} D^{+}$ and $D_{2} H^{+}$ , Phys. Rev. A 112, 052819 (2025).
S. Krohn, H. Kreckel, L. Lammich, M. Lange, J. Levin, D. Schwalm, D. Strasser, R. Wester, A. Wolf, and D. Zajfman, Electron induced vibrational deexcitation of the molecular ions $H_{2}^{+}$ and $D_{2}^{+}$ , in Dissociative Recombination of Molecular Ions with Electrons, edited by S. L. Guberman (Springer US, Boston, MA, 2003), pp. 127–138.
H. Buhr, H. B. Pedersen, S. Altevogt, V. M. Andrianarijaona, H. Kreckel, L. Lammich, S. Novotny, D. Strasser, J. Hoffmann, M. Lange, M. Lestinsky, M. B. Mendes, M. Motsch, O. Novotný, D. Schwalm, X. Urbain, D. Zajfman, and A. Wolf, Electron collisions with $^{4} {He}_{2}^{+}$ at the TSR, J. Phys.: Conf. Ser. 192, 012013 (2009).
A. Petrignani, W. J. van der Zande, P. C. Cosby, F. Hellberg, R. D. Thomas, and M. Larsson, Vibrationally resolved rate coefficients and branching fractions in the dissociative recombination of $O_{2}^{+}$ , J. Chem. Phys. 122, 014302 (2005).
H. Hus, F. Youssif, A. Sen, and J. B. A. Mitchell, Merged-beam studies of the dissociative recombination of $H_{3}^{+}$ ions with low internal energy, Phys. Rev. A 38, 658 (1988).
M. Larsson, B. McCall, and A. Orel, The dissociative recombination of $H_{3}^{+}$ — A saga coming to an end? Chem. Phys. Lett. 462, 145 (2008).
V. Kokoouline, C. H. Greene, and B. D. Esry, Mechanism for the destruction of $H_{3}^{+}$ ions by electron impact, Nature (London) 412, 891 (2001).
V. Kokoouline and C. H. Greene, Theory of dissociative recombination of $D_{3 h}$ triatomic ions applied to $H_{3}^{+}$ , Phys. Rev. Lett. 90, 133201 (2003).
S. F. dos Santos, V. Kokoouline, and C. H. Greene, Dissociative recombination of $H_{3}^{+}$ in the ground and excited vibrational states, J. Chem. Phys. 127, 124309 (2007).
C. Jungen and S. T. Pratt, Jahn-Teller interactions in the dissociative recombination of $H_{3}^{+}$ , Phys. Rev. Lett. 102, 023201 (2009).
B. M. Dinelli, S. Miller, and J. Tennyson, Bands of $H_{3}^{+}$ up to $4 ν_{2}$ : Rovibrational transitions from first principles calculations, J. Mol. Spectrosc. 153, 718 (1992).
A. Znotins, F. Grussie, A. Wolf, X. Urbain, and H. Kreckel, An approach for multi-color action spectroscopy of highly excited states of $H_{3}^{+}$ , J. Mol. Spectrosc. 378, 111476 (2021).
X. Urbain, A. Dochain, R. Marion, T. Launoy, and J. Loreau, Photodissociation as a probe of the $H_{3}^{+}$ avoided crossing seam, Philos. Trans. R. Soc. A 377, 20180399 (2019).
L. Berger, F. Grussie, F. Nuesslein, O. Novotný, A. Znotins, J. Fréreux, X. Urbain, and H. Kreckel, Characterization of a simple gas expansion ion source for intense pulses of subthermal molecular ions, Rev. Sci. Instrum. 96, 013301 (2025).
F. Merkt, K. Höveler, and J. Deiglmayr, Reactions of $H_{2}$ , HD, and $D_{2}$ with $H_{2}^{+}, {HD}^{+}$ , and $D_{2}^{+}$ : Product-channel branching ratios and simple models, J. Phys. Chem. Lett. 13, 864 (2022).
H. Kreckel, J. Tennyson, D. Schwalm, D. Zajfman, and A. Wolf, Rovibrational relaxation model for $H_{3}^{+}$ , New J. Phys. 6, 151 (2004).
H. Poth, Electron cooling: Theory, experiment, application, Phys. Rep. 196, 135 (1990).
D. Paul, M. Grieser, F. Grussie, R. von Hahn, L. W. Isberner, Á. Kálosi, C. Krantz, H. Kreckel, D. Müll, D. A. Neufeld, D. W. Savin, S. Schippers, P. Wilhelm, A. Wolf, M. G. Wolfire, and O. Novotný, Experimental determination of the dissociative recombination rate coefficient for rotationally cold ${CH}^{+}$ and its implications for diffuse cloud chemistry, Astrophys. J. 939, 122 (2022).
N. Jain, Á. Kálosi, F. Nuesslein, D. Paul, P. Wilhelm, S. G. Ard, M. Grieser, R. von Hahn, M. C. Heaven, E. Miliordos, D. Maffucci, N. S. Shuman, A. A. Viggiano, A. Wolf, and O. Novotný, Near-thermo-neutral electron recombination of titanium oxide ions, J. Chem. Phys. 158, 144305 (2023).
Á. Kálosi, L. Gamer, M. Grieser, R. von Hahn, L. W. Isberner, J. I. Jäger, H. Kreckel, D. A. Neufeld, D. Paul, D. W. Savin, S. Schippers, V. C. Schmidt, A. Wolf, M. G. Wolfire, and O. Novotný, Dissociative recombination of rotationally cold ${OH}^{+}$ and its implications for the cosmic ray ionization rate in diffuse clouds, Astrophys. J. Lett. 955, L26 (2023).
Á. Kálosi, M. Grieser, L. W. Isberner, H. Kreckel, Å. Larson, D. A. Neufeld, A. E. Orel, D. Paul, D. W. Savin, S. Schippers, V. C. Schmidt, A. Wolf, M. G. Wolfire, and O. Novotný, Dissociative recombination of rotationally cold ${ArH}^{+}$ , Phys. Rev. A 110, 022816 (2024).
A. E. Siegman, Lasers (University Science Books, Mill Valley, CA, 1986).
T. Furtenbacher, A. G. Császár, and J. Tennyson, MARVEL: Measured active rotational-vibrational energy levels, J. Mol. Spectrosc. 245, 115 (2007).
M. Goto, B. J. McCall, T. R. Geballe, T. Usuda, N. Kobayashi, H. Terada, and T. Oka, Absorption line survey of $H_{3}^{+}$ toward the Galactic center sources I. GCS 3-2 and GC IRS3, Publ. Astron. Soc. Jpn. 54, 951 (2002).
T. Oka, T. R. Geballe, M. Goto, T. Usuda, Benjamin, J. McCall, and N. Indriolo, The central 300 pc of the Galaxy probed by infrared spectra of $H_{3}^{+}$ and CO. I. Predominance of warm and diffuse gas and high $H_{2}$ ionization rate, Astrophys. J. 883, 54 (2019).
J. Le Bourlot, E. Roueff, F. Le Petit, F. Kehrein, A. Oetjens, and H. Kreckel, Understanding the temperatures of $H_{3}^{+}$ and $H_{2}$ in diffuse interstellar sightlines, Mol. Phys. 122, e2182612 (2024).
U. Hechtfischer, Z. Amitay, P. Forck, M. Lange, J. Linkemann, M. Schmitt, U. Schramm, D. Schwalm, R. Wester, D. Zajfman, and A. Wolf, Near-threshold photodissociation of cold ${CH}^{+}$ in a storage ring, Phys. Rev. Lett. 80, 2809 (1998).
A. Hirota, R. Igosawa, N. Kimura, S. Kuma, K. C. Chartkunchand, P. M. Mishra, M. Lindley, T. Yamaguchi, Y. Nakano, and T. Azuma, Radiative cooling dynamics of isolated $N_{2} O^{+}$ ions in a cryogenic electrostatic ion storage ring, Phys. Rev. A 102, 023119 (2020).
A. P. O’Connor, A. Becker, K. Blaum, C. Breitenfeldt, S. George, J. Göck, M. Grieser, F. Grussie, E. A. Guerin, R. von Hahn, et al., Photodissociation of an internally cold beam of ${CH}^{+}$ ions in a cryogenic storage ring, Phys. Rev. Lett. 116, 113002 (2016).
Á. Kálosi, M. Grieser, R. von Hahn, U. Hechtfischer, C. Krantz, H. Kreckel, D. Müll, D. Paul, D. W. Savin, P. Wilhelm, A. Wolf, and O. Novotný, Laser probing of the rotational cooling of molecular ions by electron collisions, Phys. Rev. Lett. 128, 183402 (2022).
L. H. Andersen, A. P. Rasmussen, H. B. Pedersen, and N. Klinkby, Time-resolved cryogenic action spectroscopy of dipole-bound states in phenoxide, Phys. Rev. Lett. 134, 193002 (2025).
H. Kreckel, 2026, “H3+ Spectroscopy in the Cryogenic Storage Ring”, Edmond, V1, 2026, https://doi.org/10.17617/3.LPUACU.

Phys. Rev. Research 8, 043045– Published 14 October, 2026

Vol. 8, Iss. 4 — October - December 2026

Received 30 March 2026
Accepted 19 August 2026

DOI: https://doi.org/10.1103/w9q1-yk99

Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Open access publication funded by Max Planck Society.

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Population pumping of vibrational and rotational quantum states in the triatomic hydrogen ion observed by electron-beam-assisted high-resolution spectroscopy

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