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.

China

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 investigate the Klein-Gordon (KG) oscillators in a global monopole (GM) spacetime in Eddington-inspired Born-Infeld (EiBI) gravity and a Wu-Yang magnetic monopole (WYMM). We discuss the gravitational effects in the presence of Ricci scalar curvature <math altimg='si1.svg'><mi>R</mi><mo linebreak='goodbreak' linebreakstyle='after'>=</mo><msubsup><mrow><mi>R</mi></mrow><mrow><mi>&#965;</mi></mrow><mrow><mi>&#965;</mi></mrow></msubsup></math>. It is observed that the presence of the Ricci scalar curvature, effectively and manifestly, introduces a force field that makes the corresponding quantum mechanical repulsive core more repulsive. Similar effect is also observed for the EiBI-gravitational field. We reiterate and report that the corresponding bosonic KG-oscillator quantum mechanical system admits a solution in the form of confluent Heun functions, the truncation of which into a physically admissible polynomial is shown to be associated with some parametric correlations/conditions. The use of such conditions/correlations is mandatory and yields a set of allowed/restricted quantum mechanical orbital <italic>&#8467;</italic>-excitations, for all radial quantum numbers <math altimg='si2.svg'><msub><mrow><mi>n</mi></mrow><mrow><mi>r</mi></mrow></msub><mo>&#8805;</mo><mn>0</mn></math>. Our procedure is shown to be quite handy, in the sense that it allows one to retrieve results for KG-oscillators in GM-spacetime in different EiBI-gravity and Ricci scalar curvature settings.

Türkiye

Omar Mustafa

KG-oscillators in Eddington-inspired Born-Infeld gravity: Wu-Yang magnetic monopole and Ricci scalar curvature effects

The dark photon is a promising candidate for the dark matter which comprises most of the matter in our visible Universe. Via kinetic mixing with the Standard Model it can also be resonantly converted to photons in an electromagnetic cavity, offering novel experimental possibilities for the discovery and study of dark matter. We report the results of a pathfinder dark photon dark matter cavity search experiment performed at Hunan Normal University and the Institute of Physics, Chinese Academy of Sciences, representing the first stage of the Axion and dark Photon EXperiment program. Finding no statistically significant excess, we place an upper limit on the kinetic mixing parameter <math><mrow><mo>|</mo><mi>χ</mi><mo>|</mo><mo>&lt;</mo><mn>3.7</mn><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>13</mn></mrow></msup></mrow></math> around <math><mrow><msub><mrow><mi>m</mi></mrow><mrow><mi>A</mi></mrow></msub><mo>≃</mo><mn>29.5</mn><mtext> </mtext><mtext> </mtext><mi>μ</mi><mi>eV</mi></mrow></math> at 90% confidence level. This result exceeds other constraints on dark photon dark matter in this frequency range by roughly an order of magnitude.

Dong He

Jie Fan

Xin Gao

Yu Gao

Nick Houston

Zhongqing Ji

Yirong Jin

Chuang Li

Jinmian Li

Tianjun Li

Shi-hang Liu

Jia-Shu Niu

Zhihui Peng

Liang Sun

Zheng Sun

Jia Wang

Puxian Wei

Lina Wu

Zhongchen Xiang

Qiaoli Yang

Chi Zhang

Wenxing Zhang

Xin Zhang

Dongning Zheng

Ruifeng Zheng

Jian-yong Zhou

Dark photon constraints from a 7.139 GHz cavity haloscope experiment

We consider Klein–Gordon (KG) particles in a global monopole (GM) spacetime within Eddington-inspired Born–Infeld gravity (EiBI-gravity) and in a Wu–Yang magnetic monopole (WYMM). We discuss a set of KG-oscillators in such spacetime settings. We propose a textbook power series expansion for the KG radial wave function that allows us to retrieve the exact energy levels for KG-oscillators in a GM spacetime and a WYMM without EiBI-gravity. We, moreover, report some conditionally exact, closed form, energy levels (through some parametric correlations) for KG-oscillators in a GM spacetime and a WYMM within EiBI-gravity, and for massless KG-oscillators in a GM spacetime and a WYMM within EiBI-gravity under the influence of a Coulomb plus linear Lorentz scalar potential. We report the effects of the Eddington parameter  $$\kappa $$  <math> <mi>κ</mi> </math>  , GM-parameter  $$\alpha $$  <math> <mi>α</mi> </math>  , WYMM strength  $$\sigma $$  <math> <mi>σ</mi> </math>  , KG-oscillators’ frequency  $$\Omega $$  <math> <mi>Ω</mi> </math>  , and the coupling parameters of the Coulomb plus linear Lorentz scalar potential, on the spectroscopic structure of the KG-oscillators at hand. Such effects are studied over a vast range of the radial quantum number  $$n_r\ge 0$$  <math> <mrow> <msub> <mi>n</mi> <mi>r</mi> </msub> <mo>≥</mo> <mn>0</mn> </mrow> </math>   and include energy levels clustering at  $$\kappa&gt;&gt;1$$  <math> <mrow> <mi>κ</mi> <mo>&gt;</mo> <mo>&gt;</mo> <mn>1</mn> </mrow> </math>   (i.e., extreme EiBI-gravity), and at  $$|\sigma |&gt;&gt;1$$  <math> <mrow> <mo>|</mo> <mi>σ</mi> <mo>|</mo> <mo>&gt;</mo> <mo>&gt;</mo> <mn>1</mn> </mrow> </math>   (i.e., extreme WYMM strength).

Brazil

A. Soares

C. Pereira

R. Vitória

On the Klein–Gordon oscillators in Eddington-inspired Born-Infeld gravity global monopole spacetime and a Wu–Yang magnetic monopole

The leading-order chiral Lagrangian for the baryon octet and decuplet states coupled to Goldstone bosons and external sources contains six low-energy constants. Five of them are fairly well-known from phenomenology, but the sixth one is practically unknown. This coupling constant provides the strength of the (p-wave) coupling of Goldstone bosons to decuplet states. Its size and even sign are under debate. Quark models and quantum chromodynamics (QCD) for a large number of colors provide predictions, but some recent phenomenological analyses even suggest an opposite sign for the Delta-pion coupling. The Goldberger-Treiman relation connects this coupling constant to the axial charge of the Delta baryon. This suggests a Wu-type experiment to determine the unknown low-energy constant. While this is not feasible in the Delta sector because of the large hadronic width of the Delta, there is a flavor symmetry related process that is accessible; the weak semileptonic decay of the Omega baryon to a spin <math><mrow><mn>3</mn><mo>/</mo><mn>2</mn></mrow></math> cascade baryon. A broad research program is suggested that can pin down at least the rough size and the sign of the last unknown low-energy constant of the leading-order Lagrangian. It encompasses experimental measurements, in particular the forward-backward asymmetry of the semileptonic decay, together with a determination of the quark-mass dependences using lattice QCD for the narrow decuplet states and chiral perturbation theory to extrapolate to the Delta sector. Besides discussing the strategy of the research program, the present work provides a feasibility check based on a simple leading-order calculation.

Sweden

Magnus Bertilsson

Stefan Leupold

Goldberger-Treiman relation and Wu-type experiment in the decuplet sector

We construct new three-family  $${{\mathcal {N}}}=1$$  <math> <mrow> <mi>N</mi> <mo>=</mo> <mn>1</mn> </mrow> </math>   supersymmetric Pati–Salam models from intersecting D6-branes with original gauge group  $$\textrm{U}(4)_C \times \textrm{USp}(2)_L \times \textrm{U}(2)_R$$  <math> <mrow> <mtext>U</mtext> <msub> <mrow> <mo>(</mo> <mn>4</mn> <mo>)</mo> </mrow> <mi>C</mi> </msub> <mo>×</mo> <mtext>USp</mtext> <msub> <mrow> <mo>(</mo> <mn>2</mn> <mo>)</mo> </mrow> <mi>L</mi> </msub> <mo>×</mo> <mtext>U</mtext> <msub> <mrow> <mo>(</mo> <mn>2</mn> <mo>)</mo> </mrow> <mi>R</mi> </msub> </mrow> </math>   on a Type IIA  $${\mathbb {T}}^6/({\mathbb {Z}}_2\times {\mathbb {Z}}_2)$$  <math> <mrow> <msup> <mrow> <mi>T</mi> </mrow> <mn>6</mn> </msup> <mo>/</mo> <mrow> <mo>(</mo> <msub> <mi>Z</mi> <mn>2</mn> </msub> <mo>×</mo> <msub> <mi>Z</mi> <mn>2</mn> </msub> <mo>)</mo> </mrow> </mrow> </math>   orientifold. We find that replacing a  $$\textrm{U}(2)$$  <math> <mrow> <mtext>U</mtext> <mo>(</mo> <mn>2</mn> <mo>)</mo> </mrow> </math>   with a  $$\textrm{USp}(2)$$  <math> <mrow> <mtext>USp</mtext> <mo>(</mo> <mn>2</mn> <mo>)</mo> </mrow> </math>   group severely restricts the number of three-generation supersymmetric models such that there are only five inequivalent models. Exchanging the left and right sectors, we obtain five dual models with gauge group  $$\textrm{U}(4)_C \times \textrm{U}(2)_L \times \textrm{USp}(2)_R$$  <math> <mrow> <mtext>U</mtext> <msub> <mrow> <mo>(</mo> <mn>4</mn> <mo>)</mo> </mrow> <mi>C</mi> </msub> <mo>×</mo> <mtext>U</mtext> <msub> <mrow> <mo>(</mo> <mn>2</mn> <mo>)</mo> </mrow> <mi>L</mi> </msub> <mo>×</mo> <mtext>USp</mtext> <msub> <mrow> <mo>(</mo> <mn>2</mn> <mo>)</mo> </mrow> <mi>R</mi> </msub> </mrow> </math>  . These ten models have different gauge coupling relations at string scale. The highest wrapping number is 4, and one of the models contains no filler O6-planes. Moreover, we discuss in detail the particle spectra, the composite particles through strong coupling dynamics, and the exotic particle decouplings. Also, we study how to realize the string-scale gauge coupling relations in some models.

Adeel Mansha

Mudassar Sabir

Three-family supersymmetric Pati–Salam models with symplectic groups from intersecting D6-branes

It is well-known that three-family supersymmetric Pati–Salam models from intersecting D6-branes, where either one or both of the  $$\textrm{U}(2)$$  <math> <mrow> <mtext>U</mtext> <mo>(</mo> <mn>2</mn> <mo>)</mo> </mrow> </math>   gauge factors are replaced by a  $$\textrm{USp}(2)$$  <math> <mrow> <mtext>USp</mtext> <mo>(</mo> <mn>2</mn> <mo>)</mo> </mrow> </math>   group, are quite scarce. In order to construct all such kind of models with generic additional gauge symmetries, we fix the observable sectors and study all the possible hidden sectors. Thus, we are able to completely determine all types of such kind of the inequivalent models on a  $$\mathbb {T}^6/(\mathbb {Z}_2\times \mathbb {Z}_2)$$  <math> <mrow> <msup> <mi>T</mi> <mn>6</mn> </msup> <mo>/</mo> <mrow> <mo>(</mo> <msub> <mi>Z</mi> <mn>2</mn> </msub> <mo>×</mo> <msub> <mi>Z</mi> <mn>2</mn> </msub> <mo>)</mo> </mrow> </mrow> </math>   orientifold from IIA string theory. We find the gauge coupling relations to be highly sensitive to the variations in the hidden sector. One of the models exhibits the gauge coupling unification for a particular solution at the string scale. In addition, we perform scan on the hidden sector variations for the models presented in  arXiv:2112.09632  , whose gauge coupling relations are still preserved. Thus, we fix the gap in the previous study and complete the model building for all the inequivalent models.

The hidden sector variations in the  $$\mathcal{N}=1$$  <math> <mrow> <mi>N</mi> <mo>=</mo> <mn>1</mn> </mrow> </math>   supersymmetric three-family Pati–Salam models from intersecting D6-branes

We have constructed all the three-family   <math> <mi>N</mi> </math>  $$ \mathcal{N} $$  = 1 supersymmetric Pati-Salam models from intersecting D6-branes, and obtained 33 independent models in total. But how to realize the string-scale gauge coupling relations in these models is a big challenge. We first discuss how to decouple the exotic particles in these models. In addition, we consider the adjoint chiral mulitplets for SU(4) C  and SU(2) L  gauge symmetries, the Standard Model (SM) vector-like particles from D6-brane intersections, as well as the vector-like particles from the   <math> <mi>N</mi> </math>  $$ \mathcal{N} $$  = 2 subsector. We show that the gauge coupling relations at string scale can be achieved via two-loop renormalization group equation running for all these supersymmetric Pati-Salam models. Therefore, we propose a concrete way to obtain the string-scale gauge coupling relations for the generic intersecting D-brane models.

South Korea

Rui Sun

String-scale gauge coupling relations in the supersymmetric Pati-Salam models from intersecting D6-branes

All the possible three-family  $${\mathcal N}=1$$  <math> <mrow> <mi>N</mi> <mo>=</mo> <mn>1</mn> </mrow> </math>   supersymmetric Pati–Salam models constructed with intersecting D6-branes from Type IIA orientifolds on  $$T^6/(\mathbb {Z}_2\times \mathbb {Z}_2)$$  <math> <mrow> <msup> <mi>T</mi> <mn>6</mn> </msup> <mo>/</mo> <mrow> <mo>(</mo> <msub> <mi>Z</mi> <mn>2</mn> </msub> <mo>×</mo> <msub> <mi>Z</mi> <mn>2</mn> </msub> <mo>)</mo> </mrow> </mrow> </math>   are recently presented in  arXiv:2112.09632  . Taking models with largest wrapping number 5 and approximate gauge coupling unification at GUT scale as examples, we show string scale gauge coupling unification can be realized through two-loop renormalization group equation running by introducing seven pairs of vector-like particles from  $${\mathcal N}=2$$  <math> <mrow> <mi>N</mi> <mo>=</mo> <mn>2</mn> </mrow> </math>   sector. The number of these introduced vector-like particles are fully determined by the brane intersection numbers while there are two D6-brane parallel to each other along one two-torus. We expect this will solve the gauge coupling unification problem in the generic intersecting brane worlds by introducing vector-like particles that naturally included in the  $${\mathcal N}=2$$  <math> <mrow> <mi>N</mi> <mo>=</mo> <mn>2</mn> </mrow> </math>   sector.

Weikun He

The final model building for the supersymmetric Pati–Salam models from intersecting D6-branes

We propose the generic no-scale inflation inspired from string theory compactifications. We consider the Kähler potentials with an inflaton field <math><mrow><mi>φ</mi></mrow></math>, as well as one, two, and three Kähler moduli. Also, we consider the renormalizable superpotential of <math><mi>φ</mi></math> in general. We study the spectral index and tensor-to-scalar ratio in details, and find the viable parameter spaces which are consistent with the Planck and BICEP/Keck experimental data on the cosmic microwave background (CMB). The spectral index is <math><msub><mi>n</mi><mi>s</mi></msub><mo>≃</mo><mn>1</mn><mi>−</mi><mn>2</mn><mo>/</mo><mi>N</mi><mo>∼</mo><mn>0.965</mn></math> for all models, and the tensor-to-scalar ratio <math><mi>r</mi></math> is <math><mi>r</mi><mo>≃</mo><mn>12</mn><mo>/</mo><msup><mi>N</mi><mn>2</mn></msup></math>, <math><mn>83</mn><mo>/</mo><msup><mi>N</mi><mn>4</mn></msup></math> and <math><mn>4</mn><mo>/</mo><msup><mi>N</mi><mn>2</mn></msup></math> for the one, two and three moduli models, respectively. The particular <math><mi>r</mi></math> for two moduli model comes from the contributions of the non-negligible higher order term in potential. In the three moduli model, the scalar potential is similar to the global supersymmetry, but the Kähler potential is different. The E model with <math><mi>α</mi><mo>=</mo><mn>1</mn></math> and T model with <math><mi>α</mi><mo>=</mo><mn>1</mn><mo>/</mo><mn>3</mn></math> can be realized in the one modulus model and the three moduli model, respectively. Interestingly, the models with quadratic and quartic potentials still satisfy the current tight bound on <math><mi>r</mi></math> after embedding into no-scale supergravity.

Generic no-scale inflation inspired from string theory compactifications