We present a model-independent extraction of the $$\phi $$ – $$^{4}\textrm{He}$$ scattering length from near-threshold $$\phi $$ photoproduction on helium-4, based on LEPS Collaboration data for the coherent process $$\gamma + {}^{4}\textrm{He} \rightarrow \phi + {}^{4}\textrm{He}$$ and the Vector Meson Dominance framework. Assuming an energy-independent differential cross section, we extract the absolute value of the $$\phi -^4\!\textrm{He}$$ scattering length $$|\alpha _{\phi ^{4}\textrm{He}}| = (3.33 \pm 0.06) \times 10^{-4}~\textrm{fm}$$ from a fit at threshold $$t_{\text {thr}}$$ . This value is orders of magnitude smaller than those for $$\phi N$$ and $$\phi d$$ scattering length, indicating an inverse dependence of $$|\alpha _{VA}|$$ on the target nucleus mass. Our results provide new insight into the $$\phi $$ –nucleus interaction, supporting the notion of weak $$\phi $$ –nucleus coupling. We further explore the dependence of $$|\alpha _{VA}|$$ on the vector meson mass, the target atom mass, and the threshold energy. An approximate exponential suppression of $$|\alpha _{VA}|$$ is observed with increasing vector meson mass or target atom mass, indicating that heavier vector mesons or heavier target nuclei exhibit weaker couplings in vector meson–nucleus interactions.

China

Chengdong Han

Wei Kou

Rong Wang

Xurong Chen

First extraction of the $$\phi $$ - $$^{4}\textrm{He}$$ scattering length from near-threshold $$\phi $$ photoproduction on helium-4

Inclusive electron scattering at carefully chosen kinematics can isolate scattering from the high-momentum nucleons in short-range correlations (SRCs). SRCs are produced by the hard, short-distance interactions of nucleons in the nucleus, and because the two-nucleon (2N) SRCs arise from the same N-N interaction in all nuclei, the cross section in the SRC-dominated regime is identical up to an overall scaling factor. This scaling behavior has been used to identify SRC dominance and to measure the contribution of SRCs in a wide range of nuclei. We examine this scaling behavior over a range of momentum transfers using new data on 2H, 3H, and 3He, and find an expanded scaling region compared to heavy nuclei. Motivated by this improved scaling, we examine the 3H and 3He data in kinematics where three-nucleon SRCs may play an important role. The data for the largest struck nucleon momenta are consistent with isolation of scattering from three-nucleon SRCs, and suggest that the very highest momentum nucleons in 3He have a nearly isospin-independent momentum configuration.

United States

S. Li

S.N. Santiesteban

J. Arrington

R. Cruz-Torres

L. Kurbany

D. Abrams

Saudi Arabia

S. Alsalmi

Croatia

D. Androic

K. Aniol

T. Averett

C. Ayerbe Gayoso

J. Bane

S. Barcus

J. Barrow

A. Beck

Italy

V. Bellini

H. Bhatt

D. Bhetuwal

D. Biswas

D. Bulumulla

A. Camsonne

J. Castellanos

J. Chen

J.P. Chen

D. Chrisman

M.E. Christy

C. Clarke

S. Covrig

K. Craycraft

D. Day

D. Dutta

E. Fuchey

C. Gal

F. Garibaldi

T.N. Gautam

Japan

T. Gogami

J. Gomez

P. Guèye

A. Habarakada

T.J. Hague

J.O. Hansen

F. Hauenstein

W. Henry

D.W. Higinbotham

R.J. Holt

C.E. Hyde

K. Itabashi

M. Kaneta

A. Karki

A.T. Katramatou

C.E. Keppel

M. Khachatryan

V. Khachatryan

P.M. King

Israel

I. Korover

T. Kutz

N. Lashley-Colthirst

W.B. Li

H. Liu

N. Liyanage

E. Long

Canada

J. Mammei

P. Markowitz

R.E. McClellan

F. Meddi

D. Meekins

S. Mey-Tal Beck

R. Michaels

Slovenia

Germany

M. Mihovilovič

A. Moyer

S. Nagao

V. Nelyubin

D. Nguyen

M. Nycz

M. Olson

L. Ou

V. Owen

C. Palatchi

B. Pandey

A. Papadopoulou

S. Park

S. Paul

T. Petkovic

Ukraine

R. Pomatsalyuk

S. Premathilake

V. Punjabi

R.D. Ransome

P.E. Reimer

J. Reinhold

S. Riordan

J. Roche

Puerto Rico

V.M. Rodriguez

A. Schmidt

B. Schmookler

E.P. Segarra

Armenia

A. Shahinyan

S. Širca

K. Slifer

P. Solvignon

T. Su

Inclusive studies of two- and three-nucleon short-range correlations in 3H and 3He

The Gamow shell model (GSM) framework is extended to the study of weakly bound hypernuclei. As an initial application, we investigate the neutron-rich He hyper-isotopes from <math altimg='si1.svg'><msubsup><mrow /><mrow><mi mathvariant='normal'>&#923;</mi></mrow><mrow><mn>6</mn></mrow></msubsup></math>He to <math altimg='si2.svg'><msubsup><mrow /><mrow><mi mathvariant='normal'>&#923;</mi></mrow><mrow><mn>9</mn></mrow></msubsup></math>He, accurately treating the unbound or loosely bound character of hypernuclear many-body states. The energy spectra, calculated using a phenomenological Hamiltonian with an effective <italic>YN</italic> interaction, show good agreement with available experimental data. In particular, neutron-emitting resonant states are predicted for the neutron-rich nuclei 5&#8722;8He and the hypernucleus <math altimg='si1.svg'><msubsup><mrow /><mrow><mi mathvariant='normal'>&#923;</mi></mrow><mrow><mn>6</mn></mrow></msubsup></math>He. Furthermore, neutron densities exhibit the long-range character of weakly bound and resonant states. This study demonstrates that GSM is a practical tool for describing the complex structure of hypernuclei, especially for those close to drip lines.

Xin Li

Nicolas Michel

Jianguo Li

Xian-Rong Zhou

Gamow shell model description of neutron-rich He hyper-isotopes

We investigate Λ production in the ( <math altimg='si146.svg'><msup><mrow><mi>&#960;</mi></mrow><mrow><mo linebreak='badbreak' linebreakstyle='after'>+</mo></mrow></msup></math>, <math altimg='si3.svg'><msup><mrow><mi>K</mi></mrow><mrow><mo linebreak='badbreak' linebreakstyle='after'>+</mo></mrow></msup></math>) reaction on a 6Li target at <math altimg='si4.svg'><msub><mrow><mi>p</mi></mrow><mrow><msup><mrow><mi>&#960;</mi></mrow><mrow><mo linebreak='badbreak' linebreakstyle='after'>+</mo></mrow></msup></mrow></msub><mo linebreak='goodbreak' linebreakstyle='after'>=</mo><mn>1.05</mn></math> GeV/ <italic>c</italic>, using the distorted-wave impulse approximation (DWIA) with the Fermi-averaged <math altimg='si5.svg'><msup><mrow><mi>&#960;</mi></mrow><mrow><mo linebreak='badbreak' linebreakstyle='after'>+</mo></mrow></msup><mi>n</mi><mo stretchy='false'>&#8594;</mo><msup><mrow><mi>K</mi></mrow><mrow><mo linebreak='badbreak' linebreakstyle='after'>+</mo></mrow></msup><mi mathvariant='normal'>&#923;</mi></math> amplitudes. The calculated spectrum is in good agreement with the experimental data, suggesting that <math altimg='si1.svg'><mmultiscripts><mrow><mi mathvariant='normal'>He</mi></mrow><mprescripts /><mrow><mi mathvariant='normal'>&#923;</mi></mrow><mrow><mn>4</mn></mrow></mmultiscripts></math>- <italic>d</italic> configurations play a key role in describing the &#923; continuum states of <math altimg='si23.svg'><msubsup><mrow /><mrow><mi mathvariant='normal'>&#923;</mi></mrow><mrow><mn>6</mn></mrow></msubsup></math>Li near and above the <math altimg='si8.svg'><mmultiscripts><mrow><mi mathvariant='normal'>He</mi></mrow><mprescripts /><none /><mrow><mn>3</mn></mrow></mmultiscripts><mo linebreak='goodbreak' linebreakstyle='after'>+</mo><mi>d</mi><mo linebreak='goodbreak' linebreakstyle='after'>+</mo><mi mathvariant='normal'>&#923;</mi></math> threshold. Our analysis shows that the <math altimg='si1.svg'><mmultiscripts><mrow><mi mathvariant='normal'>He</mi></mrow><mprescripts /><mrow><mi mathvariant='normal'>&#923;</mi></mrow><mrow><mn>4</mn></mrow></mmultiscripts></math> hypernucleus as a hyperfragment is prominently produced through <italic>D</italic>-wave resonances with <math altimg='si9.svg'><msup><mrow><mi>J</mi></mrow><mrow><mi>P</mi></mrow></msup><mo linebreak='goodbreak' linebreakstyle='after'>=</mo><msup><mrow><mn>3</mn></mrow><mrow><mo linebreak='badbreak' linebreakstyle='after'>+</mo></mrow></msup></math>, <math altimg='si10.svg'><msup><mrow><mn>2</mn></mrow><mrow><mo linebreak='badbreak' linebreakstyle='after'>+</mo></mrow></msup></math>, and <math altimg='si11.svg'><msup><mrow><mn>1</mn></mrow><mrow><mo linebreak='badbreak' linebreakstyle='after'>+</mo></mrow></msup></math> in the <math altimg='si108.svg'><mmultiscripts><mrow><mi mathvariant='normal'>He</mi></mrow><mprescripts /><mrow><mi mathvariant='normal'>&#923;</mi></mrow><mrow><mn>4</mn></mrow></mmultiscripts><mo linebreak='goodbreak' linebreakstyle='after'>+</mo><mi>d</mi></math> channel at a large momentum transfer <math altimg='si13.svg'><mi>q</mi><mo>&#8771;</mo><mn>360</mn></math>&#8211;400 MeV/ <italic>c</italic>. These findings provide theoretical evidence for the production of a <math altimg='si1.svg'><mmultiscripts><mrow><mi mathvariant='normal'>He</mi></mrow><mprescripts /><mrow><mi mathvariant='normal'>&#923;</mi></mrow><mrow><mn>4</mn></mrow></mmultiscripts></math> hyperfragment via a cluster-like mechanism in the 6Li( <math altimg='si146.svg'><msup><mrow><mi>&#960;</mi></mrow><mrow><mo linebreak='badbreak' linebreakstyle='after'>+</mo></mrow></msup></math>, <math altimg='si3.svg'><msup><mrow><mi>K</mi></mrow><mrow><mo linebreak='badbreak' linebreakstyle='after'>+</mo></mrow></msup></math>) reaction.

Toru Harada

Yoshiharu Hirabayashi

Evidence for <math altimg='si1.svg'><mmultiscripts><mrow><mi mathvariant='normal'>He</mi></mrow><mprescripts /><mrow><mi mathvariant='normal'>&#923;</mi></mrow><mrow><mn>4</mn></mrow></mmultiscripts></math> hyperfragment production in the 6Li( <italic>&#960;</italic> +, <italic>K</italic> +) reaction

Observations of anomalous angular correlations in electron-positron pairs produced from excited states of <math xmlns="http://www.w3.org/1998/Math/MathML"><mmultiscripts><mi>He</mi><mprescripts></mprescripts><none></none><mn>4</mn></mmultiscripts><mo>,</mo><mo> </mo><mmultiscripts><mi>Be</mi><mprescripts></mprescripts><none></none><mn>8</mn></mmultiscripts></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML"><mmultiscripts><mi mathvariant="normal">C</mi><mprescripts></mprescripts><none></none><mn>12</mn></mmultiscripts></math> nuclei have been suggested as being due to the creation and subsequent decay of a new light particle of mass <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mo>∼</mo><mn>17</mn><mspace width="0.16em"></mspace><mi>MeV</mi></mrow></math>. 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 <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mmultiscripts><mi>He</mi><mprescripts></mprescripts><none></none><mrow><mn>4</mn></mrow></mmultiscripts></mrow></math> nuclear wave function dubbed the “hexadiquark.” We calculate the invariant <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup></mrow></math> mass spectrum for the electromagnetic transition from a new excitation of <math xmlns="http://www.w3.org/1998/Math/MathML"><mmultiscripts><mi>He</mi><mprescripts></mprescripts><none></none><mn>4</mn></mmultiscripts></math>, 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 <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msup><mi>E</mi><mo>*</mo></msup><mo>=</mo><mn>17.9</mn><mo>±</mo><mn>1</mn><mspace width="0.16em"></mspace><mi>MeV</mi></mrow></math> 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 <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mn>6</mn><mi>C</mi></msub></math> interactions of <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mrow><mi>SU</mi><mo>(</mo><mn>3</mn><mo>)</mo></mrow><mi>C</mi></msub></math> 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 <math xmlns="http://www.w3.org/1998/Math/MathML"><mmultiscripts><mi>He</mi><mprescripts></mprescripts><none></none><mn>4</mn></mmultiscripts></math> and other <math xmlns="http://www.w3.org/1998/Math/MathML"><mi>α</mi></math>-cluster nuclei.

Valery Kubarovsky

Jennifer Rittenhouse West

Stanley J. Brodsky

Quantum chromodynamics resolution of the ATOMKI anomaly in <math xmlns="http://www.w3.org/1998/Math/MathML"><mmultiscripts><mi>He</mi><mprescripts></mprescripts><none></none><mn>4</mn></mmultiscripts></math> nuclear transitions

Superfluid <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mmultiscripts><mrow><mi>He</mi></mrow><mprescripts></mprescripts><none></none><mrow><mn>4</mn></mrow></mmultiscripts></mrow></math> is an ideal candidate for the direct detection of light dark matter via nuclear recoils thanks to its low nuclear mass and the possibility to reach a low-detection-energy threshold by exploiting the generated quasiparticles. The design of future detectors based on this target, such as the DELight experiment, requires a proper understanding of the formation and partitioning of the signal for different energy depositions from various sources. This work presents an overview of the physical processes involved in the energy deposition of recoiling electrons and ions, and it describes a Monte Carlo approach to the partitioning of the signal into different channels. Despite an overall good agreement with existing literature, differences in the region of interest for light dark matter searches below 200 eV are observed.

Francesco Toschi

Axel Brunold

Lea Burmeister

Klaus Eitel

Christian Enss

Eleanor Fascione

Torben Ferber

Rahel Gabriel

Lena Hauswald

Felix Kahlhoefer

Sebastian Kempf

Markus Klute

Belina von Krosigk

Sebastian Lindemann

United Kingdom

Benedikt Maier

Marc Schumann

Melih Solmaz

Kathrin Valerius

Friedrich Carl Wagner

Signal partitioning in superfluid <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mmultiscripts><mrow><mi>He</mi></mrow><mprescripts></mprescripts><none></none><mn>4</mn></mmultiscripts></mrow></math>: A Monte Carlo approach

Precise direct cosmic-ray (CR) measurements provide an important probe to study the energetic particle sources in our Galaxy, and the interstellar environment through which these particles propagate. Uncertainties on hadronic models, ion-nucleon cross sections in particular, are currently the limiting factor toward obtaining more accurate CR ion flux measurements with calorimetric space-based experiments. We present an energy-dependent measurement of the inelastic cross section of protons and helium-4 nuclei (alpha particles) on a <math><mrow><msub><mrow><mi>Bi</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></math><math><msub><mtext>Ge</mtext><mn>3</mn></msub><msub><mi>O</mi><mn>12</mn></msub></math> target, using 88 months of data collected by the DAMPE space mission. The kinetic energy range per nucleon of the measurement points ranges from 18 GeV to 9 TeV for protons, and from <math><mrow><mn>5</mn><mtext> </mtext><mi>GeV</mi><mo>/</mo><mi>n</mi></mrow></math> to <math><mrow><mn>3</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi><mo>/</mo><mi>n</mi></mrow></math> for helium-4 nuclei. Our results lead to a significant improvement of the CR flux normalization. In the case of helium-4, these results correspond to the first cross section measurements on a heavy target material at energies above <math><mrow><mn>10</mn><mtext> </mtext><mi>GeV</mi><mo>/</mo><mi>n</mi></mrow></math>.

F. Alemanno

Q. An

Switzerland

P. Azzarello

F. C. T. Barbato

P. Bernardini

X. J. Bi

I. Cagnoli

M. S. Cai

E. Casilli

E. Catanzani

J. Chang

D. Y. Chen

J. L. Chen

Z. F. Chen

P. Coppin

M. Y. Cui

T. S. Cui

Y. X. Cui

H. T. Dai

A. De Benedittis

I. De Mitri

F. de Palma

A. Di Giovanni

Q. Ding

T. K. Dong

Z. X. Dong

G. Donvito

D. Droz

J. L. Duan

K. K. Duan

R. R. Fan

Y. Z. Fan

F. Fang

K. Fang

C. Q. Feng

L. Feng

J. M. Frieden

P. Fusco

M. Gao

F. Gargano

K. Gong

Hadronic cross section measurements with the DAMPE space mission using 20 GeV-10 TeV cosmic-ray protons and <math><mrow><mmultiscripts><mrow><mi>He</mi></mrow><mprescripts></mprescripts><none></none><mrow><mn>4</mn></mrow></mmultiscripts></mrow></math>