The solar steady emission in gamma rays is due to the interactions of Galactic cosmic rays with the solar atmosphere and with the low-energy solar photon field via inverse Compton scattering. The emission is sensitive to the magnetic field nearby the Sun and to the cosmic-ray transport in the magnetic field in the inner Solar System. Modeling the inverse Compton emission in the presence of a magnetic field is, therefore, crucial to better interpret the observations. In a previous work, we have presented a comprehensive calculation of the secondary productions due to the collision of cosmic rays with the solar atmosphere in the presence of magnetic fields. In this paper, we present a general approach to calculate the (anisotropic) inverse Compton scattering in a 3D Monte Carlo simulation, also in the presence of magnetic and electric fields. After a short review of the scattering process of photons with electrons, examples of inverse Compton emission are presented, including the predictions for the Sun.

Italy

M.N. Mazziotta

3D Monte Carlo calculation of the inverse Compton emission from the Sun and stars in the presence of magnetic and electric fields

We present the first lattice result of the near threshold $ \Lambda_c\Lambda_c $ scattering with $ I(J^P) = 0(0^+) $ . The calculation is performed on two $ N_f = 2+1 $ Wilson-Clover ensembles with pion mass $ m_\pi \sim 303 $ MeV and lattice spacing $ a = 0.07746 $ fm. Lüscher's finite volume method is utilized to extract the scattering parameters from the finite-volume spectrum. The coupled channel $ \Xi_{cc}N $ is ignored in the scattering analysis based on the observation that the energy levels computed from the $ \Lambda_c\Lambda_c $ and $ \Xi_{cc}N $ operators do not mix. The $ \Sigma_c\Sigma_c $ channel is not included either since the energy range explored in this study is well below its threshold. Our results indicate that the interaction in the $ \Lambda_c\Lambda_c $ single channel is repulsive, and the scattering length is determined to be $ a_0 = -0.21(4)(8) $ fm, where the first error is statistical and the second is systematic.

China

Hanyang Xing

Yiqi Geng

Chuan Liu

Liuming Liu

Peng Sun

Jiajun Wu

Zhicheng Yan

Ruilin Zhu

Lattice QCD study of Λ $\textit{c}$ Λ $\textit{c}$ scattering * Supported by NSFC (12293060, 12293061, 12293063, 12175279, 12435002, 12322503, 12175239). L. Liu also acknowledges the Strategic Priority Research Program of the Chinese Academy of Sciences with (XDB34030301) and Guangdong Major Project of Basic and Applied Basic Research (2020B0301030008). We also acknowledge the Science and Education Integration Young Faculty Project of University of Chinese Academy of Sciences (YSBR-101)

The discovery of solar neutrinos confirmed that the inner workings of the Sun generally match our theoretical understanding of the fusion process. Solar neutrinos have also played a role in discovering that neutrinos have mass and that they oscillate. We combine the latest solar neutrino data along with other oscillation data from reactors to determine the Sun's density profile. We derive constraints given the current data and show the anticipated improvements with more reactor neutrino data from JUNO constraining the true oscillation parameters and more solar neutrino data from DUNE which should provide a crucial measurement of <italic>hep</italic> neutrinos.

United States

Peter B. Denton

Charles Gourley

Determining the density of the sun with neutrinos

We present the first lattice QCD calculation of the quark transverse spin-momentum correlation, i.e., the T-odd Boer-Mulders function of the pion, using large-momentum effective theory. The calculation is done at three lattice spacings <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>a</mi><mo>=</mo><mo stretchy="false">{</mo><mn>0.098</mn><mo>,</mo><mn>0.085</mn><mo>,</mo><mn>0.064</mn><mo stretchy="false">}</mo><mtext> </mtext><mtext> </mtext><mi>fm</mi></mrow></math> and pion masses <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo>∼</mo><mn>350</mn><mtext> </mtext><mtext> </mtext><mi>MeV</mi></math>, with pion momenta up to 1.8 GeV. The matrix elements are renormalized in a state-of-the-art scheme and extrapolated to the continuum and infinite momentum limit. We have implemented the perturbative matching up to the next-to-next-to-leading order and carried out a renormalization-group resummation. Our results provide valuable input for phenomenological analyses of the Boer-Mulders single-spin asymmetry.

Germany

Lisa Walter

Jun Hua

Sebastian Lahrtz

Lingquan Ma

Andreas Schäfer

Hai-Tao Shu

Yushan Su

Wei Wang

Xiaonu Xiong

Yi-Bo Yang

Jian-Hui Zhang

Qi-An Zhang

Quark transverse spin-momentum correlation of the pion from lattice QCD: The Boer-Mulders function

In this study, we investigate the $R^2$ corrections to the dissociation of heavy quarkonium in the Gauss-Bonnet gravitational background. We analyze the impact of the Gauss-Bonnet parameter $\lambda_{\rm GB}$ on the spectral function of charmonium and bottomonium and examine the effect of $\lambda_{\rm GB}$ on the dissociation of heavy quarkonium. Our results show that $\lambda_{\rm GB}$ reduces the peak height and increases the peak width of the spectral function, suggesting that $\lambda_{\rm GB}$ enhances the dissociation of heavy quarkonium. We also discuss the variation in the dissociation of heavy quarkonium with the ratio of shear viscosity to entropy density and observe that the dissociation is easier in more perfect plasma. Additionally, we observe that the temperature decreases the peak height and widens the peak, thereby accelerating the dissociation.

Zhou-Run Zhu

Manman Sun

Rui Zhou

Jinzhong Han

$\textit{R}$ $^{2}$ corrections to holographic heavy quarkonium dissociation * Rui Zhou supported by the Science and Technology Development Plan Project of Henan Province, China (242102230085), the National Natural Science Foundation of China (12404470), the High Level Talents Research and Startup Foundation Projects for Doctors of Zhoukou Normal University, China (ZKNUC2023017). Manman Sun supported by the National Natural Science Foundation of China (12305076). Zhou-Run Zhu supported by the High Level Talents Research and Startup Foundation Projects for Doctors of Zhoukou Normal University, China (ZKNUC2023018)

The Sun is not quite a perfect sphere, and its oblateness, thought to be induced through its rotation, has been measured using optical observations of its radius. Its gravitational quadrupole moment can then be deduced using solar models, or through helioseismology, and it can also be determined from measurements of its gravitational effects on Mercury’s orbit. The various assessments do not appear to agree, with the most complete and precise orbital assessments being in slight excess of other determinations. This may speak to the existence of a nonluminous disk or ring, where we also note evidence for a circumsolar dust ring within Mercury’s orbit from the Solar TErrestrial RElations Observatory (STEREO) mission. Historically, too, a protoplanetary disk may have been key to reconciling the Sun’s metallicity with its neutrino yield. The distribution of the nonluminous mass within Mercury’s orbit can modify the relative size of the optical and orbital quadrupole moments in different ways. We develop how we can use these findings to limit the mass of a dark disk, ring, or halo in the immediate vicinity of the Sun, and we note how future observational studies of the inner Solar System can not only refine these constraints but can also help to identify and to assess the mass of its dark-matter component.

Brazil

Gustavo F.S. Alves

Susan Gardner

Pedro Machado

Mohammadreza Zakeri

Does the Sun have a dark disk?

We report a lattice QCD calculation of the parton distribution function (PDF) of a deuteronlike dibaryon system using large-momentum effective theory. The calculation is done on three Wilson-clover ensembles with a fixed lattice spacing <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>a</mi><mo>=</mo><mn>0.105</mn><mtext> </mtext><mtext> </mtext><mi>fm</mi></mrow></math> and two pion masses. The lattice matrix elements are computed at proton momenta up to 2.46 GeV, with the signal of high-momentum modes being improved by applying the momentum smearing technique. The state-of-the-art renormalization, matching, and extrapolation are then applied to obtain the final result of the light-cone PDF. A comparison between the result of the dibaryon system and the sum of the proton and neutron PDFs is also given.

Chen Chen

Fei Yao

Kuan Zhang

Parton distribution function of a deuteronlike dibaryon system from lattice QCD

We report on the first global analysis of transverse-momentum dependent helicity distributions of the proton. The analysis is performed at next-to-leading order with the evolution factor at next-to-next-to-leading-logarithmic accuracy. Nonzero signals are determined for up and down quarks, and their <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>k</mi><mi>T</mi></msub></math>-integrated polarization is consistent with analyses in collinear factorization, while the distributions of other flavors are loosely constrained by existing data. With increasing transverse momentum, quarks at large <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>x</mi></math> become less polarized while those at small <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>x</mi></math> become more polarized.

Ke Yang

Tianbo Liu

Yuxiang Zhao

Bo-Qiang Ma

First Extraction of Transverse-Momentum Dependent Helicity Distributions

We present the determination of the charm quark mass, the masses, and decay constants of charmed mesons using thirteen <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>2</mn><mo>+</mo><mn>1</mn></mrow></math> flavor gauge ensembles at five different lattice spacings <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>a</mi><mo>∈</mo><mo stretchy="false">[</mo><mn>0.05</mn><mo>,</mo><mn>0.11</mn><mo stretchy="false">]</mo><mtext> </mtext><mtext> </mtext><mi>fm</mi></math>, 8 pion masses <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>π</mi></msub><mo>∈</mo><mo stretchy="false">(</mo><mn>130</mn><mo>,</mo><mn>360</mn><mo stretchy="false">)</mo><mtext> </mtext><mtext> </mtext><mi>MeV</mi></math>, and several values of the strange quark mass, which allows us to do the chiral and continuum extrapolation. These ensembles are generated through the stout smeared clover fermion action and Symanzik gauge actions with the tadpole improvement. By absorbing the discretization errors into the masses and field normalization of the charm quark, we manage to suppress the discretization error of the charmed meson mass and all the S-wave open charmed meson decay constants to a few percent or even less at lattice spacing <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>a</mi><mo>∼</mo><mn>0.1</mn><mtext> </mtext><mtext> </mtext><mi>fm</mi></math>. Moreover, discretization errors for other quantities are also significantly reduced. The continuum extrapolated charm quark mass, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>c</mi></msub><mo stretchy="false">(</mo><msub><mi>m</mi><mi>c</mi></msub><mo stretchy="false">)</mo><mo>=</mo><mn>1.2933</mn><mo stretchy="false">(</mo><mn>72</mn><mo stretchy="false">)</mo><mo stretchy="false">(</mo><mn>95</mn><mo stretchy="false">)</mo><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math> in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mover accent="true"><mi>MS</mi><mo stretchy="true">¯</mo></mover></math> scheme, is determined using QED-subtracted <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>D</mi><mi>s</mi></msub></math> meson mass and nonperturbative renormalization. Predictions of the open and close charm mesons using this charm quark mass agree with the experimental values at 0.1–0.5% level uncertainty. We obtained <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>D</mi><mrow><mo stretchy="false">(</mo><mi>s</mi><mo stretchy="false">)</mo></mrow></msub></math> decay constants and also by far the most precise <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>D</mi><mrow><mo stretchy="false">(</mo><mi>s</mi><mo stretchy="false">)</mo></mrow><mo>*</mo></msubsup></math> decay constants <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>f</mi><msup><mi>D</mi><mo>*</mo></msup></msub><mo>=</mo><mn>0.2292</mn><mo stretchy="false">(</mo><mn>26</mn><mo stretchy="false">)</mo><mo stretchy="false">(</mo><mn>17</mn><mo stretchy="false">)</mo><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>f</mi><msubsup><mi>D</mi><mi>s</mi><mo>*</mo></msubsup></msub><mo>=</mo><mn>0.2691</mn><mo stretchy="false">(</mo><mn>30</mn><mo stretchy="false">)</mo><mo stretchy="false">(</mo><mn>03</mn><mo stretchy="false">)</mo><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math>.

Hai-Yang Du

Bolun Hu

Mengchu Cai

Ying Chen

Heng-Tong Ding

Xiangyu Jiang

Yu Meng

Ji-Hao Wang

Dian-Jun Zhao

Charmed meson masses and decay constants in the continuum limit from the tadpole improved clover ensembles

A new thermal regime of QCD, featuring decoupled scale-invariant infrared glue, has been proposed to exist both in pure-glue (N f =0) and “real-world” (N f =2+1 at physical quark masses) QCD. In this IR phase, elementary degrees of freedom flood the infrared, forming a distinct component independent from the bulk. This behavior necessitates non-analyticities in the theory. In pure-glue QCD, such non-analyticities have been shown to arise via Anderson-like mobility edges in Dirac spectra (λ IR = 0, ±λ A ≠ 0), as manifested in the dimension function d IR(λ). Here, we present the first evidence, based on lattice QCD calculation at a=0.105 fm, that this mechanism is also at work in real-world QCD, thus supporting the existence of the proposed IR regime in nature. An important aspect of our results is that, while at T = 234 MeV we find a dimensional jump between zero modes and lowest near-zero modes very close to unity (d IR = 3 to d IR ≃ 2), similar to the IR phase of pure-glue QCD, at T = 187 MeV we observe a continuous λ-dependence. This suggests that thermal states just above the chiral crossover are non-analytically (in T) connected to thermal state at T = 234 MeV, supporting the key original proposition that the transition into the IR regime occurs at a temperature strictly above the chiral crossover.