Tue·Jan 23, 2024Tuesday·January 23, 2024

1. 01*

   A closer look at post-decay $t\bar{t}$ entanglement

   J. A. Aguilar-Saavedra🇪🇸

   Top pair production is ideally suited to observe post-decay entanglement, thus providing a novel test of quantum mechanics. We provide top polarised decay amplitudes that can be used to compute semi-analytical predictions and, in particular, to better understand {\em why} the post-decay entanglement arises. We obtain predictions for the LHC, identifying general phase space regions where experimental measurements of $tW$ entanglement are feasible. We also give predictions for polarised $e^{+}{e}^{-}$ collisions, focusing on the possibility that the post-decay $tW$ entanglement is larger than the $t\bar{t}$ one.

   hep-phhep-exPRD(2024)·51 citations
2. 02*

   Study on the mixing of ${\Xi }_c$ and ${\Xi }_c^{\prime }$ by the transition ${\Xi }_b\to {\Xi }_c^{{(}^{\prime })}$

   Hong-Wei Ke🇨🇳 · Gang-Yang Fang🇨🇳 · Yan-Liang Shi🇺🇸

   Recently, the LHCb collaboration has observed the decays ${\Xi }_b^0\to {\Xi }_c^{+}{D}_s^{-}$ and ${\Xi }_b^{-}\to {\Xi }_c^0{D}_s^{-}$. They measured the relative branching fractions times the ratio of beauty-baryon production cross-sections $\mathcal{R}(\frac{{\Xi }_b^0}{{\Lambda }_b})\equiv \frac{\sigma ({\Xi }_b^0)}{\sigma ({\Lambda }_b^0)}\times \frac{B({\Xi }_b^0\to {\Xi }_c^{+}{D}_s^{-})}{B({\Lambda }_b^0\to {\Lambda }_c^{+}{D}_s^{-})}$ and $\mathcal{R}(\frac{{\Xi }_b^{-}}{{\Lambda }_b})\equiv \frac{\sigma ({\Xi }_b^{-})}{\sigma ({\Lambda }_b^0)}\times \frac{B({\Xi }_b^{-}\to {\Xi }_c^0{D}_s^{-})}{B({\Lambda }_b^0\to {\Lambda }_c^{+}{D}_s^{-})}$. Once the ratio $\frac{\sigma ({\Xi }_b^0)}{\sigma ({\Lambda }_b^0)}$ or $\frac{\sigma ({\Xi }_b^{-})}{\sigma ({\Lambda }_b^0)}$ is known, one can determine the relative branching fractions which can be used to exam the mixing of ${\Xi }_c$ and ${\Xi }_c^{\prime }$. In previous literature, ${\Xi }_c$ and ${\Xi }_c^{\prime }$ were assumed to belong to SU(3)${}_F$ antitriple and sextet, respectively. However, recent experimental measurements such as the ratio $\Gamma ({\Xi }_{cc}\to {\Xi }_c{\pi }^{+})/\Gamma ({\Xi }_{cc}\to {\Xi }_c^{\prime }{\pi }^{+})$ indicate the spin-flavor structures of ${\Xi }_c$ and ${\Xi }_c^{\prime }$ are a mixture of ${\Xi }_c^{\bar{3}}$ and ${\Xi }_c^6$. The exact value of mixing angle $\theta$ is still under debate. In theoretical models, the mixing angle was fitted to be about $16.27^{\circ }\pm 2.30^{\circ }$ or $85.54^{\circ }\pm 2.30^{\circ }$ based on decay channels ${\Xi }_{cc}\to {\Xi }_{cc}^{{(}^{\prime })}$. While in lattice calculation, a small angle ($1.2^{\circ }\pm 0.1^{\circ }$) is preferred. To address such discrepancy and test the mixing of ${\Xi }_c$ and ${\Xi }_c^{\prime }$, here we propose the analysis of semileptonic and non-leptonic decays of ${\Xi }_b\to {\Xi }_c$ and ${\Xi }_b\to {\Xi }_c^{{}^{\prime }}$. We calculate the decay rate of ${\Xi }_b\to {\Xi }_c$ and ${\Xi }_b\to {\Xi }_c^{{}^{\prime }}$ based on light-front quark model and study the effect of the mixing angle on the ratios of weak decays ${\Xi }_b\to {\Xi }_c$ and ${\Xi }_b\to {\Xi }_c^{{}^{\prime }}$.....

   hep-phhep-exPRD(2024)·12 citations
3. 03*

   $\pi$- and $K$-Mesons Properties for Large $N_f$

   Aftab Ahmad🇵🇰

   The restoration of dynamical chiral symmetry for a higher number of light-quark flavors $N_f$ implies suppression of the dynamically generated quark mass. The study of various larger values of $N_f$ may have a greater impact on the internal structure of light hadrons. In this work, we study the properties of the $\pi$- (pion) and $K$-meson (kaon), such as the mass, condensate, and leptonic decay constant, for various $N_f$. We use the symmetry-preserving vector-vector flavor-dependent contact interaction model of quark. The dynamical quark masses are calculated using the Schwinger-Dyson equation (SDE). The masses of pion ($m_{\pi }$) and kaon ($m_K$) for different values of $N_f$ and are determined using the homogeneous Bethe-Salpeter equation. For fixed $N_c=3$ and $N_f$ is increased, the dynamically generated quark mass $M_{u/d}$ ( mass of up and down quarks), strange quark mass ($M_s$), meson in-condensate ${\kappa }_{(\pi ,K)}^{1/3}$, and decay constant $f_{(\pi ,K)}$. monotonically decrease as a function of $N_f$, except for the pion and kaon mass $m_{(\pi ,K)}$, which increase above a critical value of $N_f$ around $8$. This is the region where chiral symmetry is restored and the pion and kaon behave as free particles, similar to thier behavior in the the presence of a heat bath. The results obtained for fixed $N_f=2$ and $N_c=3$ are fairly in decent agreement with experimentally calculated statistics and previous model calculations based on the Schwinger-Dyson equation (SDE) and Bethe-Salpeter equation (BSE).

   hep-phnucl-thInt.J.Theor.Phys.(2026)·2 citations
4. 04*

   Squeezed correlations of bosons with nonzero widths for expanding sources

   Yong Zhang🇨🇳 · Peng Ru🇨🇳

   We explore the squeezed back-to-back correlation (SBBC) and investigate how the squeezing effect influences the Hanbury Brown-Twiss (HBT) interferometry using an expanding Gaussian source with non-zero width. The SBBC and HBT of $D^0$ and $\varphi$ mesons with finite in-medium widths are studied. The expanding flow of the source may enhance the SBBC strength of $D^0{\bar{D}}^0$ and $\varphi \varphi$ in the low momentum region but suppress the SBBC in the larger momentum region. The squeezing effect suppresses the influence of flow on the HBT radii, which is significant for two identical bosons with large pair momentum or with large mass. Due to the squeezing effect, the relationship between the HBT radii and the pair momentum exhibits non-flow behavior for $D^0{D}^0$ pair. Likewise, non-flow behavior also appears in the HBT radii of $\varphi \varphi$ with large pair momentum. This phenomenon may bring new insights for studying the squeezing effect.

   hep-phPRC(2024)·3 citations
5. 05*

   Heavy ion collisions from $\sqrt{s_{NN}}$ of 62.4 GeV down to 4 GeV in the EPOS4 framework

   K. Werner🇫🇷 · J. Jahan🇺🇸 · I. Karpenko🇨🇿 · T. Pierog🇩🇪 · M. Stefaniak🇺🇸 · D. Vintache🇫🇷

   The EPOS4 project is an attempt to construct a realistic model for describing relativistic collisions of different systems, from proton-proton ($pp$) to nucleus-nucleus ($AA$), at energies from several TeV per nucleon down to several GeV. We argue that a parallel scattering formalism (as in EPOS4) is relevant for primary scatterings in AA collisions above 4 GeV, whereas sequential scattering (cascade) is appropriate below. We present briefly the basic elements of EPOS4, and then investigate heavy ion collisions from 62.4 GeV down to 4 GeV, to understand how physics changes with energy, studying in particular the disappearance of the fluid component at low energies.

   hep-phnucl-thPRC(2025)·16 citations
6. 06*

   The $X(3872)$ to $\psi (2S)$ yield ratio in heavy-ion collisions

   L. M. Abreu🇧🇷 · F. S. Navarra🇧🇷 · H. P. L. Vieira🇧🇷

   In this work we evaluate the $X(3872)$ to $\psi (2S)$ yield ratio ($N_X/N_{\psi (2S)}$) in Pb Pb collisions, taking into account the interactions of the $\psi (2S)$ and $X(3872)$ states with light mesons in the hadron gas formed at the late stages of these collisions. We employ an effective Lagrangian approach to estimate the thermally-averaged cross sections for the production and absorption of the $\psi (2S)$ and use them in the rate equation to determine the time evolution of $N_{\psi (2S)}$. The multiplicity of these states at the end of mixed phase is obtained from the coalescence model. The multiplicity of $X(3872)$, treated as a bound state of $(D{\bar{D}}^{\ast }+c.c.)$ and also as a compact tetraquark, was already calculated in previous works. Knowing these yields, we derive predictions for the ratio ($N_X/N_{\psi (2S)}$) as a function of the centrality, of the center-of-mass energy and of the charged hadron multiplicity measured at midrapidity $[d{N}_{ch}/d\eta (\eta <0.5)]$. Finally, we make predictions for this ratio in Pb Pb collisions at $\sqrt{s_{NN}}=5.02$ TeV to be measured by the ALICE Collaboration in the Run 3.

   hep-phnucl-thPRD(2024)·9 citations
7. 07*

   A study of experimental sensitivities to proton parton distributions with xFitter

   Lucas Kotz🇺🇸

   In collider physics, parton distribution functions (PDFs) play a crucial role in computing theoretical cross sections for scattering reactions. This study explores how different experimental data sets influence extracted PDFs in CTEQ-TEA and MSHT NNLO PDF analyses. To gauge the impact of experimental data, including the HERA and ZEUS combined charm and beauty production, LHCb 7 TeV charm and beauty production, CMS 7 TeV W+c production, and CMS 13 TeV inclusive jets, I utilize the $L_2$ sensitivity statistical indicator in the Hessian framework as a visual representation of their respective impacts. This sensitivity quantifies the statistical pulls on individual data sets against the best-fit PDFs, facilitating the identification of tensions among competing data sets. Using the QCD fitting framework xFitter, I extract the necessary values for plotting $L_2$ sensitivities for ten distinct data sets implemented in the program, employing recent PDF sets from the CTEQ-TEA and MSHT groups. The computed $L_2$ sensitivities estimate the potential impact of the examined data sets.

   hep-ph2 citations
8. 08*

   Pair production of the singlet vector-like B quark at the CLIC

   Jin-Zhong Han🇨🇳 · Yao-Bei Liu🇨🇳 · Shi-Yu Xu🇨🇳

   Vector-like quarks~(VLQs) are a common feature of many scenarios of new physics beyond the Standard Model~(SM), which generally decay into a SM third-generation quark with a SM gauge boson, or a Higgs boson. The presence of a new exotic decay mode of VLQs will reduce the branching ratios of these standard decay modes and thus relax the current mass exclusion limits from LHC experiments. Based on a model-independent framework, we investigate the prospect of discovering the pair production of the weak-singlet VLQ-$B$ at the future 3-TeV Compact Linear Collider~(CLIC), by focusing on the final states including one $Z$ boson and four $b$-jets via two types of modes: $Z\to {\ell }^{+}{\ell }^{-}$ and $Z\to \nu \bar{\nu }$. By performing a rapid detector simulation of the signal and background events, and considering the initial state radiation and beamstrahlung effects, the exclusion limit at the 95\% confidence level and the $5\sigma$ discovery prospects are respectively obtained on the branching ratio of $B\to bZ$ and the VLQ-$B$ masses at the future 3-TeV CLIC with an integrated luminosity of 5 ab${}^{-1}$.

   hep-phEPJC(2024)·9 citations
9. 09*

   Pion-production cross sections in neutrino reactions for studying generalized parton distributions of the nucleon

   Xurong Chen🇨🇳 · S. Kumano🇨🇳 · R. Kunitomo🇯🇵 · Siyu Wu🇨🇳 · Ya-Ping Xie🇨🇳

   Gravitational form factors of hadrons provide information on mass and pressure distributions in the hadrons, and they have been investigated by generalized parton distributions (GPDs). The GPDs also contain information on internal compositions of hadron spins. Understanding on the origin of hadron masses, pressures, and spins is an important topic not only in hadron physics but also as fundamental physics, and it should be clarified by the GPD studies. The spacelike and timelike GPDs have been measured at charged-lepton accelerator facilities, for example, by the virtual Compton scattering and the two-photon process, respectively. In this work, we show the ${\pi }^{\pm }$ and ${\pi }^0$ production cross sections in neutrino (antineutrino) reactions $\nu (\bar{\nu })+N\to \ell +\pi +N^{\prime }$ for measuring the GPDs of the nucleon by using the theoretical formalism of Pire, Szymanowski, and Wagner. The ${\pi }^{\pm }$-production cross sections are useful for determining gluon GPDs, whereas the ${\pi }^0$ production probes quark GPDs. In particular, we show the roles of the pion- and rho-pole terms, the contribution from each GPD term ($H$, $E$, $\tilde{H}$, $\tilde{E}$), the effects of the gluon GPDs $H_g$ and $E_g$, and the effects of the reaction energy on the neutrino cross sections. The ${\pi }^0$-production cross section is sensitive to the quark GPDs including the pion- and rho-pole GPD terms in the Efremov-Radyushkin-Brodsky-Lepage region. These cross sections could be measured at Fermilab in future. The neutrino GPD studies will play a complementary role to the projects of charged-lepton and hadron reactions for determining the accurate GPDs.

   hep-phhep-exhep-latnucl-exEPJA(2024)·6 citations
10. 10*

    Deriving the QCD evolution equations under the Abelian decomposition scheme

    Yirui Yang🇨🇳 · Wei Kou🇨🇳 · Xiaopeng Wang🇨🇳 · Yanbing Cai🇨🇳 · Xurong Chen🇨🇳

    The Abelian decomposition of QCD reveals two types of gluons: color-neutral ``neurons" and color-carrying ``chromons". This classification does not alter the overall properties of QCD, but the investigation of different types of gluon dynamics is necessary. By employing the Cho-Duan-Ge decomposition theorem, we have derived dynamic evolution equations for two types of gluons by using the time-ordered perturbation theory. We propose that the new equations are compatible with the DGLAP equations, requiring only the separate contributions of neurons and chromons to be summed. Surprisingly, with the evolution to high $Q^2$, the ratio of the number of chromons to neurons is approximately 3:1 in small-$x$ region regardless of the inputs at evolution starting point. The new gluon dynamic equations reevaluate the gluon distribution functions and allow for a elaborate inverstigation of the distinct contributions of gluons in high-energy collisions.

    hep-phEPJC(2024)·1 citation
11. 11*

    Exploring the Truth and Beauty of Theory Landscapes with Machine Learning

    Konstantin T. Matchev🇺🇸 · Katia Matcheva🇺🇸 · Pierre Ramond🇺🇸 · Sarunas Verner🇺🇸

    Theoretical physicists describe nature by i) building a theory model and ii) determining the model parameters. The latter step involves the dual aspect of both fitting to the existing experimental data and satisfying abstract criteria like beauty, naturalness, etc. We use the Yukawa quark sector as a toy example to demonstrate how both of those tasks can be accomplished with machine learning techniques. We propose loss functions whose minimization results in true models that are also beautiful as measured by three different criteria - uniformity, sparsity, or symmetry.

    hep-phcs.LGPLB(2024)·9 citations
12. 12*

    Correlating $B\to K^{(\ast )}\nu \bar{\nu }$ and flavor anomalies in SMEFT

    Feng-Zhi Chen🇨🇳 · Qiaoyi Wen🇨🇳 · Fanrong Xu🇨🇳

    The recent measurement of $\mathcal{B}(B^{+}\to K^{+}\nu \bar{\nu })$ by Belle-II reveals a $2.8\sigma$ deviation from the Standard Model (SM) prediction. Combining this with a prior Belle measurement of $\mathcal{B}(B^0\to K^{\ast 0}\nu \bar{\nu })$, the upper bound of the ratio $\mathcal{B}(B^0\to K^{\ast 0}\nu \bar{\nu })/\mathcal{B}(B^{+}\to K^{+}\nu \bar{\nu })$ is notably smaller than the SM prediction. In this work, tensions are solved within the framework of Standard Model Effective Field Theory (SMEFT). Flavor observables, described by Low-Energy Effective Field Theory (LEFT) operators, are interconnected by SMEFT at the electroweak scale. Utilizing a set of only four SMEFT operators, the FCNC process $b\to s\nu \bar{\nu }$ is correlated with $b\to s{\ell }^{+}{\ell }^{-}$, $b\to u_i\ell \bar{\nu }$, $u_j\to s\ell \bar{\nu }$, $u_j\to u_i\nu \bar{\nu }$, and $u_j\to u_i{\ell }^{+}{\ell }^{-}$. Subsequently, we obtain the latest ranges of Wilson coefficients for these four operators through a global fit that accommodates flavor anomalies such as $R_{K^{(\ast )}}$, $R_{D^{(\ast )}}$, and $\mathcal{B}(B\to K^{(\ast )}\nu \bar{\nu })$. Our findings reveal that predictions for $\mathcal{B}(B^{+}\to {\tau }^{+}{\nu }_{\tau })$ and $\mathcal{B}(D_s^{+}\to {\tau }^{+}{\nu }_{\tau })$ align well with measured values from Belle and BESIII, based on the fitted coefficients. The predicted branching fraction for $B^0\to K^{\ast 0}\nu \bar{\nu }$ is $(1.42\pm 0.74)\times 10^{-5}$, closely approaching the current experimental upper limit. Anticipation surrounds the rare decay $B_s\to {\tau }^{+}{\tau }^{-}$, expected in the near future with a branching fraction on the order of $10^{-4}$.

    hep-phnucl-thEPJC(2024)·47 citations
13. 13*

    Radiative decays of X(3872) discriminate between the molecular and compact interpretations

    B. Grinstein🇺🇸 · L. Maiani🇮🇹 · A.D. Polosa🇮🇹

    Radiative decays X --> psi(1S) + gamma and X --> psi(2S) + gamma might be expected to have a ratio of branching fractions following the phase space volumes ratio. However data suggest the opposite, indicating a value for R=B(X --> psi^prime + gamma) / B(X --> psi +gamma) consistently larger than one. In this paper we present a calculation of R for both a compact Born-Oppenheimer cc-bar q-qbar state and a DD^* molecule. In the former case R~1 or larger is found, a value to be confronted with forthcoming high statistics data analyses. In the molecular picture, with D and D^* mesons described by the universal wave function used by Voloshin, Braaten and Kusunoki, we find that R would be of order 10^-2. A more precise experimental measure would be extremely helpful in clarifying the true nature of the X(3872).

    hep-phPRD(2024)·39 citations
14. 14*

    New physics search via angular distribution of $B\to D^{\ast }\ell {\nu }_{\ell }$ decay in the light of the new lattice data

    Tejhas Kapoor🇫🇷 · Zhuo-Ran Huang🇨🇳 · Emi Kou🇫🇷

    In this article, we investigate the potential of the angular distribution of the $B\to D^{\ast }\ell {\nu }_{\ell }$ process to search for new physics signals. The Belle collaboration has analysed it to constraint $V_{cb}$ and the $B\to D^{\ast }$ form factors, under the assumption of the Standard Model. With the newly released lattice QCD data, we can perform a simultaneous fit of the form factors, $V_{cb}$ as well as new physics parameters. We use the Belle data and the lattice data to constrain right-handed new physics. In addition, we also generate unbinned pseudo-dataset and perform a sensitivity study on more general new physics models, using the lattice data.

    hep-phhep-exhep-latJHEP(2025)·11 citations
15. 15*

    Chiral perturbation theory with vector mesons and the pion form factors

    Tae-Sun Park🇰🇷

    The chiral perturbation theory (ChPT) of pions is extended to include vector mesons as well as pertinent degrees of freedom. By counting the typical momentum scale of vector mesons as order of $Q$ and vector meson masses as of the order of ${\Lambda }_{\chi }$, a consistent theory could be obtained. The explicit renormalization procedure of the theory is presented for the form factors of the pion up to one-loop accuracy. The resulting theory prediction for the form factors is in good agreement with the experimental data for a wide range of momentum transfers. The vector-meson dominance mechanism is also discussed in the systematic framework of ChPT.

    hep-phnucl-th2 citations
16. 16*

    The Bayes factor surface for searches for new physics

    Andrew Fowlie🇨🇳

    The Bayes factor surface is a new way to present results from experimental searches for new physics. Searches are regularly expressed in terms of phenomenological parameters - such as the mass and cross-section of a weakly interacting massive particle. Bayes factor surfaces indicate the strength of evidence for or against models relative to the background only model in terms of the phenomenological parameters that they predict. They provide a clear and direct measure of evidence, may be easily reinterpreted, but do not depend on choices of prior or parameterization. We demonstrate the Bayes factor surface with examples from dark matter, cosmology, and collider physics.

    hep-phastro-ph.COhep-exphysics.data-anEPJC(2024)·16 citations
17. 17*

    Axions and Primordial Magnetogenesis: the Role of Initial Axion Inhomogeneities

    Filippo Anzuini🇦🇺 · Angelo Maggi🇬🇧

    The relic density of dark matter in the $\Lambda$CDM model restricts the parameter space for a cosmological axion field, constraining the axion decay constant, the initial amplitude of the axion field and the axion mass. It is shown via lattice simulations how the relic density of axion-like particles with masses close to the one of the QCD axion is affected by axion-gauge field interactions and by initial axion inhomogeneities. For pre-inflationary axions, once the Hubble parameter becomes smaller than the axion mass, the latter starts to oscillate, and part of its energy density is spent producing gauge fields via parametric resonance. If the gauge fields are dark photons and Standard Model photons, the energy density of dark photons becomes higher than the one of the axion, while the high conductivity of the primordial plasma damps the oscillations of the photon field. Such a scenario allows for the production of small-scale, primordial magnetic fields, and it is found that the relic density of axions with a low decay constant are within the bounds set by the $\Lambda$CDM model, while GUT-scale axions are far too abundant. It is also shown that initial inhomogeneities of the axion field can change substantially the gauge field production, boosting or suppressing (depending on the axion parameters and couplings) the magnetogenesis mechanism with respect to an homogeneous axion field. It is found that when the axion mass is far lighter than the QCD axion model and the initial axion field is inhomogeneous, weak but cosmologically relevant magnetic field seeds can be generated on scales of the order of $0.1$ kpc.

    hep-phJCAP(2024)·3 citations
18. 18*

    The 3-3-1 model with exotic electric charges, right-handed neutrinos with type-I+II seesaw mechanism and its effects on LFV

    Abrar Ahmad🇵🇰 · Shakeel Mahmood🇵🇰 · Farida Tahir🇵🇰 · Wasi Uz Zaman🇵🇰 · Fizza Atif🇵🇰

    In this research, we propose a modified version of the 3-3-1 model, incorporating a type I+II seesaw mechanism and Z4 discrete symmetry, as a framework for investigating lepton flavor-violating (LFV) decays. This model successfully yields the left-handed neutrinos mass square difference in the eV scale, with specific values of mass square differences; and generates mixing angles that align with experimental data. Furthermore, we develop SARAH and SPheno algorithms tailored for our modified model, enabling us to estimate the magnitude of LFV observables. Our calculations indicate favorable results for various LFV branching ratios. These findings demonstrate improved agreement with experimental measurements compared to previously reported results, which typically fall within the range of 10^-2 to 10^-6.

    hep-phBraz.J.Phys.(2025)·0 citations
19. 19*

    Fried-Yennie gauge in pseudo-QED

    Ana Mizher🇧🇷 · Alfredo Raya🇲🇽 · Khépani Raya🇪🇸

    The Fried-Yennie gauge is a covariant gauge for which the mass-shell renormalization procedure can be performed without introducing spurious infrared divergences to the theory. It is usually applied in calculations in regular Quantum-Electrodynamics (QED), but it is particularly interesting to be employed in the framework of pseudo-QED (PQED), where fermions are constrained to 2+1 dimensions while external fields interacting with these fermions live in the bulk of a 3+1 space. In this context, the gauge parameter can be adjusted to match the power of the external momentum in the denominator of the photon propagator, simplifying the infrared region without the need of a photon mass. In this work we apply for the first time this machinery to PQED, generalizing the procedure to calculate the self energy in arbitrary dimensions, allowing of course for different dimensionality of fermions and gauge fields.

    hep-phcond-mat.othercond-mat.str-elEntropy(2024)·4 citations
20. 20*

    Plasmon-enhanced Direct Detection Method for Boosted sub-MeV Dark Matter

    Zheng-Liang Liang🇨🇳 · Liangliang Su🇨🇳 · Lei Wu🇨🇳 · Bin Zhu🇨🇳

    Plasmon, a collective mode of electronic excitation in solid-state detectors, provides a novel way to detect light dark matter (DM). In this work, we present the conditions of DM to produce plasmon resonance, requiring relativistic velocities for light DM, and generalize the collective excitation framework to account for relativistic DM. As a demonstration, we consider the cosmic ray boosted DM (CRDM) and find that the plasmon resonance can be significantly enhanced in the scenario with a light mediator. Utilizing the first data from SENSEI experiment with the skipper-CCDs at SNOLAB, we obtain a new strong limit on the sub-MeV DM-electron scattering cross section.

    hep-phPRL(2025)·33 citations
21. 21*

    ${\Lambda }_b\to P\ell$ factorization in QCD

    Lei-Yi Li🇨🇳 · Cai-Dian Lü🇨🇳 · Jin Wang🇨🇳 · Yan-Bing Wei🇨🇳

    We calculate the form factors for the baryon number violation processes of a heavy-flavor baryon decaying into a pseudoscalar meson and a lepton. In the framework of the Standard Model effective field theory, the leptoquark operators at the bottom quark scale, whose matrix elements define the form factors, are derived by integrating out the high energy physics. Under the QCD factorization approach, the form factors of the baryon number violation processes at leading power can be factorized into the convolution of the long-distance hadron wave functions as well as the short-distance hard and jet functions representing the hard scale and hard-collinear scale effects, separately. Based on measurements of the baryon number violation processes by LHCb, we further impose constraints on the new physics constants of leptoquark operators.

    hep-phPRD(2024)·6 citations
22. 22*

    A new look at $b\to s$ observables in 331 models

    Francesco Loparco🇮🇹

    Flavour changing neutral current (FCNC) processes are described by loop diagrams in the Standard Model (SM), while in 331 models, based on the gauge group $\text{SU}(3{)}_C\times \text{SU}(3{)}_L\times \text{U}(1{)}_X$, they are dominated by tree-level exchanges of a new heavy neutral gauge boson $Z^{\prime }$. Exploiting this feature, observables related to FCNC decays of $K$, $B_d$ and $B_s$ mesons can be considered in several variants of 331 models. The variants are distinguished by the value of a parameter $\beta$ that plays a key role in this framework. Imposing constraints on the $\Delta F=2$ observables, we select possible ranges for the mass of the $Z^{\prime }$ boson in correspondence to the values $\beta =\pm k/\sqrt{3}$, with $k=1,2$. The results are used to determine the impact of 331 models on $b\to s$ processes and on the correlations among them, in the light of new experimental data recently released.

    hep-phhep-exhep-latParticles(2024)·12 citations
23. 23*

    Unraveling Generalized Parton Distributions Through Lorentz Symmetry and Partial DGLAP Knowledge

    P. Dall'Olio🇪🇸 · F. De Soto🇪🇸 · C. Mezrag🇫🇷 · J.M. Morgado Chávez🇫🇷 · H. Moutarde🇫🇷 · J. Rodríguez-Quintero🇪🇸 · P. Sznajder🇵🇱 · J. Segovia🇪🇸

    Relying on the polynomiality property of generalized parton distributions, which roots on Lorentz covariance, we prove that it is enough to know them at vanishing- and low-skewness within the DGLAP region to obtain a unique extension to their entire support up to a D-term. We put this idea in practice using two methods: Reconstruction using artificial neural networks and finite-elements methods. We benchmark our results against standard models for generalized parton distributions. In agreement with the formal expectation, we obtain a very accurate reconstructions for a maximal value of the skewness as low as 20% of the longitudinal momentum fraction. This result might be relevant for reconstruction of generalized parton distribution from experimental and lattice QCD data, where computations are for now, restricted in skewness.

    hep-phnucl-thPRD(2024)·12 citations
24. 24*

    Discrete symmetries tested at 10${}^{-4}$ precision using linear polarization of photons from positronium annihilations

    Paweł Moskal🇵🇱 · Eryk Czerwiński🇵🇱 · Juhi Raj🇵🇱 · Steven D. Bass🇵🇱 · Ermias Y. Beyene🇵🇱 · Neha Chug🇵🇱 · Aurélien Coussat🇵🇱 · Catalina Curceanu🇮🇹 · Meysam Dadgar🇵🇱 · Manish Das🇵🇱 · Kamil Dulski🇮🇹 · Aleksander Gajos🇵🇱 and 29 other authors

    Discrete symmetries play an important role in particle physics with violation of CP connected to the matter-antimatter imbalance in the Universe. We report the most precise test of P, T and CP invariance in decays of ortho-positronium, performed with methodology involving polarization of photons from these decays. Positronium, the simplest bound state of an electron and positron, is of recent interest with discrepancies reported between measured hyperfine energy structure and theory at the level of $10^{-4}$ signaling a need for better understanding of the positronium system at this level. We test discrete symmetries using photon polarizations determined via Compton scattering in the dedicated J-PET tomograph on an event-by-event basis and without the need to control the spin of the positronium with an external magnetic field, in contrast to previous experiments. Our result is consistent with QED expectations at the level of 0.0007 and one standard deviation.

    hep-phnucl-exNature Commun.(2024)·37 citations
25. 25*

    Construction of a next-to-next-to-next-to-leading order approximation for heavy flavour production in deep inelastic scattering with quark masses

    Niccolò Laurenti🇮🇹

    The subject of this thesis is the construction of an approximation for the next-to-next-to-next-to leading order (N^3LO) deep inelastic scattering (DIS) massive coefficient function of the gluon for F2 in heavy quark pair production. Indeed, this object is one of the ingredients needed for the construction of any variable flavour number (factorization) scheme at O(alphas^3). The construction of such scheme is crucial for the improvement of the accuracy of the extraction of the parton distribution functions from the experimental data, that in turn will provide an improvement of the accuracy of all the theoretical predictions in high energy physics. Despite the function we are interested in is not known exactly, its expansion in some kinematic limits is available. In particular the high-scale limit (Q^2 >> m^2), high-energy limit (z->0, where z is the argument of the coefficient function) and threshold limit (z->zmax=1/(1+4m^2/Q^2)) of the exact coefficient function are all known, with the exception of some terms that we will provide in approximate form. Therefore, combining these limits in a proper way, we will construct an approximation for the unknown term of the N^3LO gluon coefficient function, that describes the exact curve in the whole range of z. Since other approximations for the N^3LO gluon coefficient functions are present in the literature, we will conclude by comparing our final approximate coefficient functions with such approximations. We will show a comparison both for the NNLO, whose exact function is known, and for the N^3LO. With our approach, we expect our results to be more accurate than previous approximations, thus providing a sufficient precision for a complete description of DIS at N^3LO and the consequent determination of N^3LO PDFs.

    hep-ph4 citations
26. 26*

    Threshold photoproduction of ${\eta }_c$ and ${\eta }_b$ using holographic QCD

    Florian Hechenberger🇦🇹 · Kiminad A. Mamo🇺🇸 · Ismail Zahed🇺🇸

    We discuss the possibility that threshold photoproduction of ${\eta }_{c,b}$ may be sensitive to the pseudovector $1^{+-}$ glueball exchange. We use the holographic construction to identify the pseudovector glueball with the Kalb-Ramond field, minimally coupled to bulk Dirac fermions. We derive the holographic C-odd form factor and its respective charge radius. Using the pertinent Witten diagrams, we derive and analyze the differential photoproduction cross section for ${\eta }_{c,b}$ in the threshold regime, including the interference from the dual bulk photon exchange with manifest vector dominance. The possibility of measuring this process at current and future electron facilities is discussed.

    hep-phnucl-thPRD(2024)·8 citations
27. 27*

    Towards a more complete description of hybrid leptogenesis

    Rohan Pramanick🇮🇳 · Tirtha Sankar Ray🇮🇳 · Arunansu Sil🇮🇳

    Hybrid leptogenesis framework combining type I and type II seesaw mechanism for neutrino mass necessarily include scattering topologies involving both the scalar triplet and the right handed neutrino. We demonstrate that a systematic inclusion of these mixed scatterings can significantly alter the evolution of the number densities exhibiting up to a factor ten deviation in the predicted asymmetry as demonstrated by our benchmark scenarios. We provide quantitative constraints on the degeneracy of the seesaw scales where the complete analysis becomes numerically significant, limiting the validity of leptogenesis being dominated by the lightest seesaw species only.

    hep-phPRD(2024)·5 citations
28. 28*

    Femtoscopy between $\pi$, $K$ and $p$ in different heavy-ion collisions at $\sqrt{s_{NN}}$ = 39 GeV

    Ting-Ting Wang🇨🇳 · Yu-Gang Ma🇨🇳 · Song Zhang🇨🇳

    Momentum correlation functions between $\pi$, $K$ and $p$ are calculated for several heavy-ion collision systems, namely ${}_5^{10}\text{B}{+}_5^{10}\text{B}$, ${}_8^{16}\text{O}{+}_8^{16}\text{O}$, ${}_{20}^{40}\text{Ca}{+}_{20}^{40}\text{Ca}$ and ${}_{79}^{197}\text{Au}{+}_{79}^{197}\text{Au}$ in central collisions as well as ${}_{79}^{197}\text{Au}{+}_{79}^{197}\text{Au}$ collision in different centralities at center of mass energy $\sqrt{s_{NN}}$ = 39 GeV within the framework of A Multi-Phase Transport (AMPT) model complemented by the Lednick$\acute{y}$ and Lyuboshitz analytical method. The results present the centrality and system-size dependence of the momentum correlation functions among pairs of $\pi$, $K$ and $p$, from which the emission source-size can be deduced. It is found that the deduced source sizes increase with the decreasing of centrality for Au + Au system or with the increasing of system-size in central collisions with different nuclear size. In addition, through the momentum correlation functions of nonidentical particle pairs gated on velocity, the average emission sequence of non-identical particles can be indicated. The results illustrate that in the small relative momentum region, protons are emitted in average earlier than ${\pi }^{+}$ and $K^{+}$, and $K^{+}$ are emitted averagely earlier than ${\pi }^{+}$. Furthermore, it seems that larger interval of the average emission order among them is exhibited for smaller collision systems. The present study sheds light on the dynamics of light particle emission at RHIC energy.

    hep-phnucl-exnucl-th1 citation
29. 29*

    Early Matter Domination at Colliders: Long Live the Glueball!

    Fady Bishara🇩🇪 · Filippo Sala🇮🇹 · Kai Schmidt-Hoberg🇩🇪

    We prove that collider searches for long-lived particles (LLPs) can test the dynamics responsible for matter domination in the early universe. In this letter we concentrate on the specific example of glueballs from a GeV-scale confining dark sector and compute the dilution of cosmological relics induced by their decay. We then show that searches for long-lived glueballs from Higgs decays test increasing values of dilution at ATLAS and CMS, CODEX-b, ANUBIS and MATHUSLA. We identify the general features that make models of early matter domination discoverable via LLPs at colliders. Our study provides a quantitative physics motivation to test longer lifetimes.

    hep-phastro-ph.COPLB(2025)·3 citations
30. 30*

    Relevance of one-loop SMEFT matching in the 2HDM

    Supratim Das Bakshi🇪🇸 · Sally Dawson🇺🇸 · Duarte Fontes🇺🇸 · Samuel Homiller🇺🇸

    The Two-Higgs Doublet Model (2HDM) is a well understood alternative to the Standard Model of particle physics. If the new particles included in the 2HDM are at an energy scale much greater than the weak scale, the theory can be matched to the Standard Model Effective Field Theory (SMEFT). We compute for the first time the complete one-loop matching at dimension-6. We compare its numerical impact with that of tree-level matching at dimension-8 by performing a global fit to single Higgs and precision electroweak measurements, and we emphasize the importance of comparing one-loop SMEFT results with corresponding one-loop results in the full 2HDM model. In the SMEFT, we consider the relative importance of both one-loop matching and the inclusion of renormalization group evolution. Our results demonstrate the necessity of studying the impact of various expansions to quantify the uncertainties of the SMEFT matching.

    hep-phPRD(2024)·15 citations
31. 31*

    Dark matter from phase transition generated PBH evaporation with gravitational waves signatures

    Debasish Borah🇮🇳 · Suruj Jyoti Das🇰🇷 · Indrajit Saha🇮🇳

    We study the possibility of generating dark matter (DM) purely from ultra-light primordial black hole (PBH) evaporation with the latter being produced from a first order phase transition (FOPT) in the early Universe. If such ultra-light PBH leads to an early matter domination, it can give rise to a doubly peaked gravitational wave (GW) spectrum in Hz-kHz ballpark with the low frequency peak generated from PBH density fluctuations being within near future experimental sensitivity. In the sub-dominant PBH regime, the FOPT generated GW spectrum comes within sensitivity due to absence of entropy dilution. In both the regimes, PBH mass from a few kg can be probed by GW experiments like BBO, ET, CE, UDECIGO etc. while DM mass gets restricted to the superheavy ballpark in the PBH dominance case. Apart from distinct DM mass ranges in the two scenarios, GW observations can differentiate by measuring their distinct spectral shapes.

    hep-phastro-ph.COPRD(2024)·22 citations
32. 32*

    Even SIMP miracles are possible

    Xiaoyong Chu🇦🇹 · Marco Nikolic🇦🇹 · Josef Pradler🇦🇹

    Strongly interacting massive particles $\pi$ have been advocated as prominent dark matter candidates when they regulate their relic abundance through odd-numbered $3\pi \to 2\pi$ annihilation. We show that successful freeze-out may also be achieved through even-numbered interactions $XX\to \pi \pi$ once bound states $X$ among the particles of the low-energy spectrum exist. In addition, $X$-formation hosts the potential of also catalyzing odd-numbered $3\pi \to 2\pi$ annihilation processes, turning them into effective two-body processes $\pi X\to \pi \pi$. Bound states are often a natural consequence of strongly interacting theories. We calculate the dark matter freeze-out and comment on the cosmic viability and possible extensions. Candidate theories can encompass confining sectors without a mass gap, glueball dark matter, or ${\varphi }^3$ and ${\varphi }^4$ theories with strong Yukawa or self-interactions.

    hep-phastro-ph.HEPRL(2024)·19 citations
33. 33*

    A Closer Look in the Mirror: Reflections on the Matter/Dark Matter Coincidence

    Arushi Bodas🇺🇸 · Manuel A. Buen-Abad🇺🇸 · Anson Hook🇺🇸 · Raman Sundrum🇺🇸

    We argue that the striking similarity between the cosmic abundances of baryons and dark matter, despite their very different astrophysical behavior, strongly motivates the scenario in which dark matter resides within a rich dark sector parallel in structure to that of the standard model. The near cosmic coincidence is then explained by an approximate ${\mathbb{Z}}_2$ exchange symmetry between the two sectors, where dark matter consists of stable dark neutrons, with matter and dark matter asymmetries arising via parallel WIMP baryogenesis mechanisms. Taking a top-down perspective, we point out that an adequate ${\mathbb{Z}}_2$ symmetry necessitates solving the electroweak hierarchy problem in each sector, without our committing to a specific implementation. A higher-dimensional realization in the far UV is presented, in which the hierarchical couplings of the two sectors and the requisite ${\mathbb{Z}}_2$-breaking structure arise naturally from extra-dimensional localization and gauge symmetries. We trace the cosmic history, paying attention to potential pitfalls not fully considered in previous literature. Residual ${\mathbb{Z}}_2$-breaking can very plausibly give rise to the asymmetric reheating of the two sectors, needed to keep the cosmological abundance of relativistic dark particles below tight bounds. We show that, despite the need to keep inter-sector couplings highly suppressed after asymmetric reheating, there can naturally be order-one couplings mediated by TeV scale particles which can allow experimental probes of the dark sector at high energy colliders. Massive mediators can also induce dark matter direct detection signals, but likely at or below the neutrino floor.

    hep-phastro-ph.COJHEP(2024)·21 citations
34. 34*

    A Cosmological Tachyon Collider: Enhancing the Long-Short Scale Coupling

    Ciaran McCulloch🇬🇧 · Enrico Pajer🇬🇧 · Xi Tong🇬🇧

    The squeezed limit of the primordial curvature bispectrum is an extremely sensitive probe of new physics and encodes information about additional fields active during inflation such as their masses and spins. In the conventional setup, additional fields are stable with a positive mass squared, and hence induce a decreasing signal in the squeezed limit, making a detection challenging. Here we consider a scalar field that is temporarily unstable by virtue of a transient tachyonic mass, and we construct models in which it is embedded consistently within inflation. Assuming IR-finite couplings between the tachyon and the inflaton, we find an exchange bispectrum with an enhanced long-short scale coupling that grows in the squeezed limit parametrically faster than local non-Gaussianity. Our approximately scale-invariant signal can be thought of as a cosmological tachyon collider. In a sizeable region of parameter space, the leading constraint on our signal comes from the cross correlation of $\mu$-type spectral distortions and temperature anisotropies of the microwave background, whereas temperature and polarization bispectra are less sensitive probes. By including anisotropic spectral distortions in the analysis, future experiments such as CMB-S4 will further reduce the allowed parameter space.

    ↳ hep-thastro-ph.COgr-qchep-phJHEP(2024)·38 citations
35. 35*

    Introduction to the second edition of "The Supersymmetric World"

    M. Shifman🇺🇸

    The first Edition of this book was released in 2000, just before the symposium ``Thirty Years of Supersymmetry'' was held at the William I. Fine Theoretical Physics Institute (FTPI) of the University of Minnesota. Founders and trailblazers of supersymmetry descended on FTPI, as well as a large crowd of younger theorists deeply involved in research in this area. Since then 23 years have elapsed and significant changes happened in supersymmetry (SUSY). Its history definitely needs an update. Such an update is presented below. The Second Edition of the revised collection will be released in 2024.

    ↳ physics.hist-phhep-ph0 citations
36. 36*

    Determination of the Energy Eigenvalues of the Varshni-Hellmann Potential

    N. Tazimi🇮🇷

    In this paper, we solve the bound state problem for Varshni-Hellmann potential via a useful technique. In our technique, we obtain the bound state solution of the Schrodinger equation for the Varshni-Hellmann potential via ansatz method. We obtain the energy eigenvalues and the corresponding eigen-functions. Also, the behavior of the energy spectra for both the ground and the excited state of the two body systems is illustrated graphically. The similarity of our results to the accurate numerical values is indicative of the efficiency of our technique.

    ↳ quant-phhep-phhep-thAdv.High Energy Phys.(2024)·1 citation
37. 37*

    Localization mechanism of $q-$form field on the brane-world by coupling with gravity

    Yong-Tao Lu🇨🇳 · Heng Guo🇨🇳 · Qun Wei🇨🇳 · Chun-E Fu🇨🇳

    It is known that the scalar fields can be trapped on branes of different types, and the $U(1)$ gauge vector fields can be localized on the thick de Sitter brane, or the thick Minkowski brane via coupling with gravity. The Kalb-Ramond fields can be localized on the Minkowski brane and the thick de-Sitter brane, with certain couplings. In this paper, with considering a coupling mechanism between the kinetic term of the $q-$form fields and the background spacetime, we investigate the localization of Kaluza-Klein modes for the $q-$form fields in $D-$dimensional spacetime. Concrete $q-$form fields are discussed within five-dimensional brane models with typical spacetime geometries: Minkowski, de Sitter, and Anti-de Sitter. In the Minkowski brane case, the zero modes of various $q-$form fields can be localized on the brane. In the de Sitter brane case, the zero mode of the $U(1)$ gauge vector fields can be localized on the brane. Lastly in the Anti-de Sitter brane case, the zero mode of the Kalb-Ramond fields can be localized on the brane. For the massive Kaluza-Klein modes of these $q-$form fields, they could be localized or quasi-localized on the brane of different types. Besides, subtle and detailed behaviors of the Kaluza-Klein modes for $q-$form fields are observed: the zero modes could be localized on both sides of the brane, and the massive modes could be localized or quasi-localized at the brane position.

    ↳ hep-thgr-qchep-phPRD(2025)·6 citations
38. 38*

    Hadronic vacuum polarization in the muon $g-2$: The short-distance contribution from lattice QCD

    Simon Kuberski🇨🇭 · Marco Cè🇮🇹 · Georg von Hippel🇩🇪 · Harvey B. Meyer🇩🇪 · Konstantin Ottnad🇩🇪 · Andreas Risch🇩🇪 · Hartmut Wittig🇩🇪

    We present results for the short-distance window observable of the hadronic vacuum polarization contribution to the muon $g-2$, computed via the time-momentum representation (TMR) in lattice QCD. A key novelty of our calculation is the reduction of discretization effects by a suitable subtraction applied to the TMR kernel function, which cancels the leading $x_0^4$-behaviour at short distances. To compensate for the subtraction, one must substitute a term that can be reliably computed in perturbative QCD. We apply this strategy to our data for the vector current collected on ensembles generated with $2+1$ flavours of O($a$)-improved Wilson quarks at six values of the lattice spacing and pion masses in the range $130-420$MeV. Our estimate at the physical point contains a full error budget and reads $(a_{\mu }^{\mathrm{hvp}}{)}^{\mathrm{SD}}=68.85(14{)}_{\mathrm{stat}}(42{)}_{\mathrm{syst}}\cdot 10^{-10}$, which corresponds to a relative precision of 0.7\%. We discuss the implications of our result for the observed tensions between lattice and data-driven evaluations of the hadronic vacuum polarization.

    ↳ hep-lathep-phJHEP(2024)·78 citations
39. 39*

    The N(1440) Roper resonance in the nuclear model with explicit mesons

    D.V.Fedorov🇩🇰

    We show that the N(1440) Roper resonance naturally appears in the nuclear model with explicit mesons as a structure in the continuum spectrum of the physical proton which in this calculation is made of a bare nucleon dressed with a pion cloud.

    ↳ nucl-thhep-phFew Body Syst.(2024)·2 citations
40. 40*

    The Scavenger Hunt for Quasar Samples to Be Used as Cosmological Tools

    Maria Giovanna Dainotti🇯🇵 · Giada Bargiacchi🇮🇹 · Aleksander Łukasz Lenart · Salvatore Capozziello🇮🇹

    Although the $\Lambda$ Cold Dark Matter model is the most accredited cosmological model, information at high redshifts ($z$) between type Ia supernovae ($z=2.26$) and the Cosmic Microwave Background ($z=1100$) is crucial to validate this model further. To this end, we have discovered a sample of 1132 quasars up to $z=7.54$ exhibiting a reduced intrinsic dispersion of the relation between ultraviolet and X-ray fluxes, ${\delta }_{\mathrm{F}}=0.22$ vs. ${\delta }_{\mathrm{F}}=0.29$ ($24\%$ less), than the original sample. This gold sample, once we correct the luminosities for selection biases and redshift evolution, enables us to determine the matter density parameter ${\Omega }_M$ with a precision of 0.09. Unprecedentedly, this quasar sample is the only one that, as a standalone cosmological probe, yields such tight constraints on ${\Omega }_M$ while being drawn from the same parent population of the initial sample.

    ↳ astro-ph.COhep-phGalaxies(2024)·20 citations
41. 41*

    Toward QCD on Quantum Computer: Orbifold Lattice Approach

    Georg Bergner🇩🇪 · Masanori Hanada🇬🇧 · Enrico Rinaldi🇯🇵 · Andreas Schafer🇩🇪

    We propose an orbifold lattice formulation of QCD suitable for quantum simulations. We show explicitly how to encode gauge degrees of freedom into qubits using noncompact variables, and how to write down a simple truncated Hamiltonian in the coordinate basis. We show that SU(3) gauge group variables and quarks in the fundamental representation can be implemented straightforwardly on qubits, for arbitrary truncation of the gauge manifold.

    ↳ hep-thhep-lathep-phnucl-th+1JHEP(2024)·35 citations
42. 42*

    Effective Abelian Lattice Gauge Field Theories for scalar-matter-monopole interactions

    K. Farakos🇬🇷 · G. Koutsoumbas🇬🇷 · Nick E. Mavromatos🇬🇷

    We present a gauge and Lorentz invariant effective field theory model for the interaction of a charged scalar matter field with a magnetic monopole source, described by an external magnetic current. The quantum fluctuations of the monopole field are described effectively by a strongly-coupled ``dual'' $U_{\mathrm{d}}(1)$ gauge field, which is independent of the electromagnetic $U_{\mathrm{em}}(1)$ gauge field. The effective interactions of the charged matter with the monopole source are described by a gauge invariant mixed Chern-Simons-like (Pontryagin-density) term between the two $U(1)$ gauge fields. The latter interaction coupling is left free, and a Lattice study of the system is performed with the aim of determining the phase structure of this effective theory. Our study shows that, in the spontaneously-broken-symmetry phase, the monopole source triggers, via the mixed Chern-Simons term, which is non-trivial in its presence, the generation of a dynamical singular configuration (magnetic-monopole-like) for the respective gauge fields. The scalar field also behaves in the broken phase in a way similar to that of the scalar sector of the `t Hooft-Polyakov monopole.

    ↳ hep-thhep-lathep-phPRD(2024)·7 citations
43. 43*

    Bayesian analysis of nontrivial features in the speed of sound inside neutron stars in light of astrophysical and pQCD constraints

    Debora Mroczek🇺🇸

    Functional forms of the neutron star Equation of State (EoS) are required to extract the viable EoS band from neutron star observations. Realistic nuclear EoS, containing deconfined quarks or hyperons, present nontrivial features in the speed of sound such as bumps, kinks, and plateaus. Using modified Gaussian processes to model EoS with nontrivial features, we show in a fully Bayesian analysis incorporating measurements from X-ray sources, gravitational wave observations, and perturbative QCD results that these features are compatible with current constraints. We find nontrivial behavior in the EoS plays a role in understanding the possible phase structure of neutron stars at densities around 2 $n_{\mathrm{sat}}$.

    ↳ nucl-thhep-phEPJ Web Conf.(2024)·1 citation
44. 44*

    A discrete model for Gell-Mann matrices

    Robert A. Wilson🇬🇧

    I propose a discrete model for the Gell-Mann matrices, which allows them to participate in discrete symmetries of three generations of four types of elementary fermions, in addition to their usual role in describing a continuous group $SU(3)$ of colour symmetries. This model sheds new light on the mathematical (rather than physical) necessity for `mixing' between the various gauge groups $SU(3)$, $SU(2)$ and $U(1)$ of the Standard Model. In particular it shows how the anti-Hermitian version of Pauli matrices can act non-trivially on a unitary version of the Gell-Mann matrices, which leads to a non-trivial mixing between the weak and strong nuclear forces. The unitary version of the Gell-Mann matrices can in turn act non-trivially on a quaternionic version of Dirac matrices, which leads to a non-trivial mixing between the strong force and the shape of spacetime defined by the Dirac matrices. Hence this model implies a mixing between the electro-weak-strong forces on the one hand and gravity, as described by General Relativity, on the other. This mixing in turn implies the necessity for both general relativistic corrections to the Standard Model of Particle Physics, and quantum corrections to General Relativity. Contrary to general expectation, both types of corrections seem to be large enough to be tested experimentally.

    ↳ math.GRhep-ph5 citations
45. 45*

    The earliest phase of relativistic heavy-ion collisions

    Margaret E. Carrington🇨🇦 · Stanislaw Mrowczynski🇵🇱

    According to the Color Glass Condensate approach to relativistic heavy-ion collisions, the earliest phase of the collision is a glasma which is made of highly populated gluon fields that can be treated classically. Using a proper time expansion we study analytically various properties of the glasma. In particular, we compute the glasma energy-momentum tensor which allows us to obtain the energy density, longitudinal and transverse pressure, collective flow, and angular momentum. We also study the role of the glasma in jet quenching by computing collisional energy loss and transverse momentum broadening.

    ↳ nucl-thhep-phActa Phys.Polon.B(2024)·4 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.