The high-density region of the QCD phase diagram displays an intricate competition between color superconductivity and the QCD Kondo effect due to color exchange in quark matter containing a single heavy quark impurity. We explore the characteristic impurity-induced superconducting subgap states arising in such systems by generalizing the surrogate model solver, recently considered in the context of condensed matter physics [<a href="http://dx.doi.org/10.1103/PhysRevB.108.L220506">Phys. Rev. B 108, L220506 (2023)</a>]. The method consists of approximating the full superconducting bulk by only a small number of effective levels whose parameters are chosen so as to best reproduce the Matsubara frequency dependence of the impurity-bulk hybridization function. We numerically solve a surrogate QCD Kondo model describing a quantum impurity color exchange coupled to a two-color two-flavor superconducting bulk. The results directly indicate the presence of multiple phase transitions as the coupling of the impurity to the bulk is increased, due to the interplay between various overscreened states. The methods introduced here are straightforward enough to be extended to more realistic QCD scenarios.

Romania

Virgil V. Baran

Denmark

Jens Paaske

Yu-Shiba-Rusinov states in color-superconducting quark matter

We study $ \cos2\phi $ azimuthal asymmetry in doubly longitudinally polarized proton-proton Drell-Yan collisions within the transverse momentum dependent factorization framework. The asymmetry arises from the convolution of the longitudinal transversity distribution $ h_{1L}^{\perp} $ for both protons. Using the Bacchetta-Delcarro-Pisano-Radici-Signori parameterization for the nonperturbative Sudakov form factor and the Wandzura-Wilczek approximation for collinear $ h_{1L}^{\perp} $ , we predict the double spin asymmetry $ A_{LL}^{\cos2\phi} $ at RHIC and NICA kinematics. Our results demonstrate sensitivity to sea quark distributions, with the asymmetry reaching up to 25% for maximal sea quark contributions. These predictions highlight the potential of polarized Drell-Yan measurements to probe sea quark dynamics and advance our understanding of nucleon structures.

China

Hui Li

Ting Hu

Liang-Liang Liu

Xiao-Yu Wang

Zhun Lu

Asymmetry ${{\boldsymbol A}_{\boldsymbol{LL}}^{\bf\cos2\boldsymbol\phi}} $ in the polarized proton-proton Drell-Yan process within TMD factorization * Hui Li is supported by Fundamental Research Program of Shanxi Province (202203021222224) and Natural Science Foundation of Shanxi Normal University (JCYJ2023021). Xiao-Yu Wang is supported by the Natural Science Foundation of Henan Province (242300421377, 232300421140)

We study the transverse momentum ( $p_T$ ) differential anisotropic flow and flow fluctuation in Pb+Pb collisions at $\sqrt{s_{_{NN}}}$ =5.02 TeV at the LHC. A (3+1)-dimensional CLVisc hydrodynamics framework with fluctuating TRENTO (or AMPT) initial conditions is utilized to simulate the space-time evolution of the quark-gluon plasma (QGP) medium. The effects of shear viscosity and the sub-nucleon structure on anisotropic flow and flow fluctuation are analyzed. Our result shows that shear viscosity tends to suppress both flow coefficients ( ${v_2\{2}\}$ , ${v_2\{4\}}$ , and ${\langle v_2\rangle}$ ) and flow fluctuation ( ${\sigma_{v_2}}$ ) owing to its smearing effect on local density fluctuation. The flow coefficients appear to be insensitive to the sub-nucleon structure, whereas the flow fluctuation ${\sigma_{v_2}}$ tends to be suppressed by the sub-nucleon structure in central collisions but enhanced in peripheral collisions. After taking into account the sub-nucleon structure effect, our numerical result can qualitatively describe the relative flow fluctuations ( ${v_2\{4\}/v_2\{2\}}$ , $F({v_2})$ ) measured by the ALICE Collaboration at the LHC. We further investigate the effects of shear viscosity, sub-nucleon structure, and initial condition model on the flow angle and flow magnitude decorrelations ( ${A_2^f}$ , ${M_2^f}$ ) using the four-particle correlation method. We find that the flow decorrelation effect is typically stronger in central collisions than in peripheral collisions. The flow angle decorrelation is found to be insensitive to the shear viscosity and sub-nucleon structure, whereas the flow magnitude decorrelation shows quite different behaviors when using the TRENTO and AMPT initial condition models. Our study sheds light on the anisotropic flow, transport properties, and initial structure of the QGP created in high-energy nuclear collisions.

Germany

Jie Zhu

Canada

Xiang-Yu Wu

Guang-You Qin

Anisotropic flow, flow fluctuation, and flow decorrelation in relativistic heavy-ion collisions: the roles of sub-nucleon structure and shear viscosity * Supported in part by the Natural Science Foundation of China (12225503, 11890710, 11890711, 11935007). Zhu Jie is supported in part by the China Scholarship Council (202306770009). Wu Xiang-Yu is supported in part by the National Science Foundation within the framework of the JETSCAPE collaboration (OAC-2004571) and in part by the Natural Sciences and Engineering Research Council of Canada. Some of the calculations were performed in the Nuclear Science Computing Center at Central China Normal University (NSC$^{3}$), Wuhan, Hubei, China.

We study the proton lifetime in the SO(10) Grand Unified Theory (GUT), which has the left–right (LR) symmetric gauge theory below the GUT scale. In particular, we focus on the minimal model without the bi-doublet Higgs field in the LR symmetric model, which predicts the LR-breaking scale at around $$10^{10-12}$$ <math><msup><mn>10</mn><mrow><mn>10</mn><mo>-</mo><mn>12</mn></mrow></msup></math> GeV. The Wilson coefficients of the proton decay operators turn out to be considerably larger than those in the minimal SU(5) GUT model especially when the Standard Model Yukawa interactions are generated by integrating out extra vector-like multiplets. As a result, we find that the proton lifetime can be within the reach of the Hyper-Kamiokande experiment even when the GUT gauge-boson mass is in the $$10^{16}$$ <math><msup><mn>10</mn><mn>16</mn></msup></math> –$$10^{17}$$ <math><msup><mn>10</mn><mn>17</mn></msup></math> GeV range. We also show that the mass of the extra vector-like multiplets can be generated by the Peccei–Quinn symmetry breaking in a consistent way with the axion dark matter scenario.

France

Yuta Hamada

Japan

Masahiro Ibe

Yu Muramatsu

Kin-ya Oda

Norimi Yokozaki

Proton decay and axion dark matter in SO(10) grand unification via minimal left–right symmetry

Using the vector exchange interaction in the local hidden gauge approach, which in the light quark sector generates the chiral Lagrangians and has produced realistic results for 
					 and the hidden charm pentaquark states, we study the meson-baryon interactions in the coupled channels that lead to the 
					 and 
					 excited states of the molecular type. We obtain seven states of the 
					 type with energies between 
					 and 
					 MeV, and one 
					 state at 
					 MeV.
				

Brazil

J. M. Dias

Qi-Xin Yu

Wei-Hong Liang

Zhi-Feng Sun

Ju-Jun Xie

Spain

E. Oset

Ξbb and Ωbbb molecular states Partly supported by the National Natural Science Foundation of China (11975083, 11947413, 11847317, 11565007, 11735003, 1191101015). Q. X Yu acknowledges the support from the National Natural Science Foundation of China (11775024, 11575023, 11805153) and China Scholarship Council. Partly supported by the Spanish Ministerio de Economia y Competitividad and European FEDER funds (FIS2017- 84038-C2-1-P B, FIS2017-84038-C2-2-P B), and the Generalitat Valenciana in the program Prometeo II-2014/068, and the project Severo Ochoa of IFIC, SEV-2014-0398

In the standard model (SM), the Cabibbo-Kobayashi-Maskawa (CKM) matrix is the only origin of flavor violations (FVs). On the other hand, in general, there are a lot of sources of the FVs in a physics beyond the SM, through the diagonalizing matrices which make Yukawa matrices diagonal. Although most of the diagonalizing matrices are unknown ones, grand unified theories (GUTs) can fix these matrices. In particular, if we consider a GUT model based on the SO(10) group, these diagonalizing matrices are strongly related to each other because of the matter unification. However, this unification causes the problem on the realization of measured SM fermion masses and mixing angles. Up to now, many people showed that supersymmetric (SUSY) threshold corrections can solve this problem, especially unfavorable fermion mass relations. In this paper, we show that how these SUSY threshold corrections affect unknown diagonalizing matrices. Since these contributions are also related to the FVs induced by SUSY particles, we can estimate the maximal effect to the diagonalizing matrices. We found that the (1, 3) and (3, 1) elements of diagonalizing matrices for quarks can be as large as the corresponding mixing angle of the CKM matrix. Moreover, we found that the higher SUSY scale can predict the larger mixing angles, although strong cancellation between the Higgs mass parameters is needed to realize the electroweak symmetry breaking.

Yoshihiro Shigekami

SUSY threshold corrections to quark and lepton mixing inspired by SO (10) GUT models

Recently, several <math><mi>B</mi></math>-physics experiments report interesting anomalies in the semi-leptonic decays of <math><mi>B</mi></math>-mesons, such as the excess in the <math><msub><mi>R</mi><msup><mi>D</mi><mrow><mo>(</mo><mo>*</mo><mo>)</mo></mrow></msup></msub></math> measurements. These anomalies seem to suggest intriguing hints of lepton flavor nonuniversality, and the <math><mi>R</mi></math>-parity violating (RPV) interactions are candidates for explaining this nonuniversality. In this paper, we discuss the RPV interactions for resolving the <math><msub><mi>R</mi><msup><mi>D</mi><mrow><mo>(</mo><mo>*</mo><mo>)</mo></mrow></msup></msub></math> anomaly with the grand unified theory (GUT) assumption. To solve the <math><msub><mi>R</mi><msup><mi>D</mi><mrow><mo>(</mo><mo>*</mo><mo>)</mo></mrow></msup></msub></math> anomaly, it is known that large RPV couplings and around 1 TeV sfermion masses are required. At the same time, large RPV couplings are conducive to realize the bottom-tau Yukawa unification which appears in the GUT models. On the other hand, there are problems for realizing favorable sfermion masses in the constrained minimal supersymetric standard model. To resolve these problems, we show that two nonuniversalities, the nonuniversal sfermion masses and the nonuniversal gaugino masses, are favorable.

Quan-Yi Hu

Xin-Qiang Li

Ya-Dong Yang

<math><mi>R</mi></math>-parity violating solutions to the <math><mrow><msub><mrow><mi>R</mi></mrow><mrow><msup><mrow><mi>D</mi></mrow><mrow><mo>(</mo><mo>*</mo><mo>)</mo></mrow></msup></mrow></msub></mrow></math> anomaly and their GUT-scale unifications

In this paper, we discuss the multi-Higgs doublet models, that could be effectively induced by the extended Standard Model (SM). In particular, we focus on the phenomenology in the supersymmetric model with left-right (LR) symmetry, where the down-type and the up-type Yukawa couplings are unified and the Yukawa coupling matrices are expected to be hermitian. In this model, several Higgs doublets are introduced to realize the realistic fermion mass matrices, and the heavy Higgs doublets have flavor changing couplings with quarks and leptons. The LR symmetry is assumed to break down at high energy to realize the Type-I seesaw mechanism. The supersymmetry breaking scale is expected to be around 100 TeV to achieve the 125 GeV Higgs. In such a setup, the flavor-dependent interaction of the Higgs fields becomes sizable, so that we especially discuss the flavor physics induced by the heavy Higgs fields in our work. Our prediction depends on the structure of neutrinos, e.g., the neutrino mass ordering. We demonstrate how the flavor structure of the SM affects the flavor violating couplings. In our analysis, we mainly focus on the four-fermi interaction induced by the scalar exchanging, and we propose a simple parameterization for the coefficients. Then, we find the correlations among the flavor observables and, for instance, see that our prediction for the μ → 3e process could be covered by the future experiment, in one case where the neutrino mass hierarchy is normal.

Syuhei Iguro

Yuji Omura

Flavor physics in the multi-Higgs doublet models induced by the left-right symmetry

Flavor symmetries are useful to realize fermion flavor structures in the standard model (SM). In particular, the discrete <math><mrow><msub><mrow><mi>A</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></math> symmetry is used to realize lepton flavor structures, and some scalars—called flavons—are introduced to break this symmetry. In many models, flavons are assumed to be much heavier than the electroweak scale. However, our previous work showed that a flavon mass around 100 GeV is allowed by experimental constraints in the <math><msub><mi>A</mi><mn>4</mn></msub></math> symmetric model with a residual <math><msub><mi>Z</mi><mn>3</mn></msub></math> symmetry. In this paper, we discuss collider searches for such a light flavon <math><msub><mi>φ</mi><mi>T</mi></msub></math>. We find that electron-photon collisions at the International Linear Collider have advantages for searching for these signals. In electron-photon collisions, flavons are produced as <math><msup><mi>e</mi><mo>−</mo></msup><mi>γ</mi><mo>→</mo><msup><mi>l</mi><mo>−</mo></msup><msub><mi>φ</mi><mi>T</mi></msub></math> and decay into two charged leptons. Then, we analyze signals of the flavor-conserving final state <math><msup><mi>τ</mi><mo>+</mo></msup><msup><mi>τ</mi><mo>−</mo></msup><msup><mi>e</mi><mo>−</mo></msup></math> and the flavor-violating final states <math><msup><mi>τ</mi><mo>+</mo></msup><msup><mi>μ</mi><mo>−</mo></msup><msup><mi>μ</mi><mo>−</mo></msup></math> and <math><msup><mi>μ</mi><mo>+</mo></msup><msup><mi>τ</mi><mo>−</mo></msup><msup><mi>τ</mi><mo>−</mo></msup></math> by carrying out numerical simulations. For the former final state, SM background can be strongly suppressed by imposing cuts on the invariant masses of final-state leptons. For the latter final states, SM background is extremely small, because in the SM there are no such flavor-violating final states. We then find that sufficient discovery significance can be obtained, even if flavons are heavier than the lower limits from flavor physics.

South Korea

Takaaki Nomura

Yusuke Shimizu

Hiroshi Yokoya

Light flavon signals at electron-photon colliders

Recent discovery of neutrino large mixings implies the large mixings in the diagonalizing matrices of 5¯ fields in SU(5) grand unified theory (GUT), while the diagonalizing matrices of 10 fields of SU(5) are expected to have small mixings like Cabibbo–Kobayashi–Maskawa matrix. We calculate the predictions of flavor changing nucleon decays (FCND) in SU(5) , SO(10) , and E6 GUT models which have the above features for mixings. We found that FCND can be the main decay mode and play an important role to test GUT models.

Nobuhiro Maekawa

Flavor changing nucleon decay