Tue·Dec 26, 2023Tuesday·December 26, 2023

1. 01*

   Signatures of baryon junctions in semi-inclusive deep inelastic scattering

   David Frenklakh🇺🇸 · Dmitri E. Kharzeev🇺🇸 · Wenliang Li🇺🇸

   Local gauge invariance of the baryon wave function leads to the emergence of a baryon junction, where three (or $N$, in $SU(N)$ gauge theory) string operators merge. The existence of baryon junction dramatically affects the dynamics of baryon stopping at high energies, and the corresponding predictions are supported by the recent data from STAR Collaboration at the Relativistic Heavy Ion Collider. Here we outline the ways in which the baryon junctions can be tested in semi-inclusive deep inelasttic scattering at Jefferson Laboratory and the future Electron Ion Collider.

   hep-phhep-exnucl-thPLB(2024)·8 citations
2. 02*

   One-loop five-parton amplitudes in the NMRK limit

   Emmet P. Byrne🇬🇧

   We analyse the real part of one-loop five-parton amplitudes in the next-to-multi-Regge kinematic (NMRK) limit, to leading power, and to finite order in the dimensional regularisation parameter. To leading logarithmic (LL) accuracy, it is known that five-parton amplitudes in this limit are given to all-orders by a single factorised expression, in which the pair of partons which are not well-separated in rapidity are described by a two-parton emission vertex. In this study, we investigate the one-loop amplitudes at next-to-leading logarithmic (NLL) accuracy, and find that is has a more complex structure. In particular, it is found that the purely gluonic amplitudes are compatible with an analogous factorisation of individual colour structures. From the one-loop amplitudes we extract one-loop two-parton emission vertices, which are functions of a subset of the momenta of the amplitude. In the multi-Regge kinematic (MRK) limit, the vertices themselves factorise into the known one-loop single-parton emission vertices and Lipatov vertex, with rapidity dependence governed by the one-loop gluon Regge trajectory, as required by compatibility with the known MRK limit of amplitudes. The one-loop two-parton emission vertices are necessary ingredients for the construction of the next-to-next-to leading order (NNLO) jet impact factors in the BFKL framework.

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

   Leptogenesis, Dark Matter and Gravitational Waves from Discrete Symmetry Breaking

   Subhaditya Bhattacharya🇮🇳 · Niloy Mondal🇮🇳 · Rishav Roshan🇬🇧 · Drona Vatsyayan🇪🇸

   We analyse a model that connects the neutrino sector and the dark sector of the universe via a mediator $\Phi$, stabilised by a discrete $Z_4$ symmetry that breaks to a remnant $Z_2$ upon $\Phi$ acquiring a non-zero vacuum expectation value ($v_{\varphi }$). The model accounts for the observed baryon asymmetry of the universe via additional contributions to the canonical Type-I leptogenesis. The $Z_4$ symmetry breaking scale ($v_{\varphi }$) in the model not only establishes a connection between the neutrino sector and the dark sector, but could also lead to gravitational wave signals that are within the reach of current and future experimental sensitivities.

   hep-phJCAP(2024)·23 citations
4. 04*

   Consistent, multidimensional differential histogramming and summary statistics with YODA 2

   Andy Buckley🇬🇧 · Louie Corpe🇫🇷 · Matthew Filipovich🇬🇧 · Christian Gutschow🇬🇧 · Nick Rozinsky🇬🇧 · Simon Thor🇸🇪 · Yoran Yeh🇬🇧 · Jamie Yellen🇬🇧

   Histogramming is often taken for granted, but the power and compactness of partially aggregated, multidimensional summary statistics, and their fundamental connection to differential and integral calculus make them formidable statistical objects, especially when very large data volumes are involved. But expressing these concepts robustly and efficiently in high-dimensional parameter spaces and for large data samples is a highly non-trivial challenge -- doubly so if the resulting library is to remain usable by scientists as opposed to software engineers. In this paper we summarise the core principles required for consistent generalised histogramming, and use them to motivate the design principles and implementation mechanics of the re-engineered YODA histogramming library, a key component of physics data-model comparison and statistical interpretation in collider physics.

   hep-phstat.COSciPost Phys.Codeb.(2025)·27 citations
5. 05*

   Are There Correlations in the HAWC and IceCube High Energy Skymaps Outside the Galactic Plane?

   Jason Kumar🇺🇸 · Carsten Rott🇺🇸 · Pearl Sandick🇺🇸 · Natalia Tapia-Arellano🇺🇸

   We use publicly-available data to perform a search for correlations of high energy neutrino candidate events detected by IceCube and high-energy photons seen by the HAWC collaboration. Our search is focused on unveiling such correlations outside of the Galactic plane. This search is sensitive to correlations in the neutrino candidate and photon skymaps which would arise from a population of unidentified point sources. We find no evidence for such a correlation, but suggest strategies for improvements with new data sets.

   hep-phastro-ph.HEPRD(2024)·2 citations
6. 06*

   Hyperorder net baryon number fluctuations in nuclear matter at low temperature

   Xinran Yang · Guoyun Shao · Weibo He

   We calculate the density fluctuations of net baryon number up to sixth order induced by the interactions of nuclear matter, and explore their relationship with the nuclear liquid-gas phase transition (LGPT), including the stable and metastable phase as well as the region far from the phase transition. The results show that dramatic density fluctuations exist in the vicinity of LGPT, and the hyperorder density fluctuations are more sensitive than the lower order ones to the interactions and structural properties of nuclear matter. The study also indicates that, even far away from the critical region of LGPT, the hadronic interactions can still lead to significant hyperorder density fluctuations. In combination with the chemical freeze-out line fitted from the experimental data, the derived results can be referred to investigate the chiral phase transition, nuclear LGPT, as well as the analysis of related experimental signals.

   hep-phnucl-thPRC(2024)·2 citations
7. 07*

   Schwinger dark matter production

   Mar Bastero-Gil🇪🇸 · Paulo B. Ferraz🇪🇸 · Lorenzo Ubaldi🇸🇮 · Roberto Vega-Morales🇪🇸

   Building on recently constructed inflationary vector dark matter production mechanisms as well as studies of magnetogenesis, we show that an inflationary dark Schwinger mechanism can generate the observed dark matter relic abundance for `dark electron' masses as light as $\sim 0.1$ eV and as heavy as $10^{12}$ GeV. The dark matter can interact very weakly via the exchange of light dark photons with a power spectrum which is peaked at very small scales, thus evading isocurvature constraints. This mechanism is viable even when (purely) gravitational particle production is negligible. Thus dark matter can be produced solely via the Schwinger effect during inflation including for light masses.

   hep-phJCAP(2024)·15 citations
8. 08*

   Axion-pion scattering at finite temperature in chiral perturbation theory and its influence in axion thermalization

   Jin-Bao Wang🇨🇳 · Zhi-Hui Guo🇨🇳 · Hai-Qing Zhou🇨🇳

   Axion-pion scattering amplitudes at finite temperatures are calculated within chiral perturbation theory up to the one loop level. Unitarization procedure is implemented to these amplitudes in order to extend the applicable range of energy and temperature. The influence of the thermal axion-pion scattering amplitudes on the $a\pi \to \pi \pi$ cross sections and the axion thermalization rate is investigated, with the emphasis on the comparison with the zero-temperature-amplitude case. A brief discussion on the cosmological implication of the axion thermalization rate, that is calculated by using the $a\pi \to \pi \pi$ amplitudes at finite temperatures, is also given. The thermal corrections to the axion-pion scattering amplitudes can cause around a $10\%$ shift of the determination of the axion decay constant $f_a$ and its mass $m_a$, comparing with the results by using the $a\pi \to \pi \pi$ amplitudes at zero temperature.

   hep-phPRD(2024)·9 citations
9. 09*

   Connecting Tribimaximal and Bitrimaximal Mixings

   Carlos Alvarado🇺🇸 · Janelly Bautista🇲🇽 · Alexander J. Stuart🇲🇽

   In this paper, we study the connection between the tribimaximal and bitrimaximal mixing patterns. In doing so, we are forced to work in a non-diagonal charged lepton basis. This leads to several relations that must hold between the lepton mixing angles. After a short discussion, we analyze the underlying flavor symmetry responsible for this prediction. Finally, we add CP violation to bitrimaximal mixing and study its effect on the flavor symmetry group.

   hep-phPLB(2024)·0 citations
10. 10*

    Analysis of $B_s^0\to {\chi }_{c1}(3872){\pi }^{+}{\pi }^{-}$ decay

    Elnaz Amirkhanlou🇮🇷 · Behnam Mohammadi🇮🇷

    Recently, the LHCb collaboration has analyzed the decay of $B_s^0\to {\chi }_{c1}(3872)(\to J/\psi {\pi }^{+}{\pi }^{-}){\pi }^{+}{\pi }^{-}$ and reported the ratio of the branching fractions to the $B_s^0\to \psi (2S)(\to J/\psi {\pi }^{+}{\pi }^{-}){\pi }^{+}{\pi }^{-}$ decay. The results of this study have measured as a ratio of branching fractions as{\setlength\arraycolsep{.75pt} \begin{eqnarray} \mathcal{R}&=&\frac{\mathcal{B}r(B_s^0\rightarrow\chi_{c1}(3872)\pi^+\pi^-)\times\mathcal{B}r(\chi_{c1}(3872)\rightarrow J/\psi\pi^+\pi^-)}{\mathcal{B}r(B_s^0\rightarrow\psi(2S)\pi^+\pi^-)\times\mathcal{B}r(\psi(2S)\rightarrow J/\psi\pi^+\pi^-)}\nonumber\\&=&(6.8\pm1.1\pm0.2)\times10^{-2},\nonumber \end{eqnarray}} and{\setlength\arraycolsep{.75pt} \begin{eqnarray} \mathcal{B_X}&=&\mathcal{B}r(B_s^0\rightarrow\chi_{c1}(3872)\pi^+\pi^-)\times\mathcal{B}r(\chi_{c1}(3872)\rightarrow J/\psi\pi^+\pi^-)\nonumber\\&=&(1.6\pm0.3\pm0.1\pm0.3)\times10^{-6}.\nonumber \end{eqnarray}} For the first time, we calculated this branching fraction using factorization. According to our calculations, ratio of branching fractions to be $\mathcal{R}=(4.38\pm 1.36)\times 10^{-2}$ at $\mu =m_b/2$ and the products related to branching fractions have been estimated ${\mathcal{B}}_{\mathcal{X}}=(1.08\pm 0.62)\times 10^{-6}$ at $\mu =m_b$. The results are consistent with the experiment reported.

    hep-phIndian J.Phys.(2025)·0 citations
11. 11*

    Renormalization-Group Evolution for the Bottom-Meson Soft Function

    Yong-Kang Huang🇨🇳 · Yao Ji🇩🇪 · Yue-Long Shen🇨🇳 · Chao Wang🇨🇳 · Yu-Ming Wang🇨🇳 · Xue-Chen Zhao🇨🇳

    We determine for the first time the renormalization-group (RG) evolution equation for the $B$-meson soft function dictating the non-perturbative strong interaction dynamics of the long-distance penguin contributions to the exclusive $b\to q{\ell }^{+}{\ell }^{-}$ and $b\to q\gamma$ decays. The distinctive feature of the ultraviolet renormalization of this fundamental distribution amplitude consists in the novel pattern of mixing positive into negative support for an arbitrary initial condition. The exact solution to this integro-differential RG evolution equation of the bottom-meson soft function is then derived with the Laplace transform technique, allowing for the model-independent extraction of the desired asymptotic behaviour at large/small partonic momenta.

    hep-phhep-exhep-latPRL(2024)·17 citations
12. 12*

    Reanalysis of the top-quark pair production via the $e^{+}{e}^{-}$ annihilation near the threshold region up to N${}^3$LO QCD corrections

    Jiang Yan🇨🇳 · Xing-Gang Wu🇨🇳 · Zhi-Fei Wu🇨🇳 · Jing-Hao Shan🇨🇳 · Hua Zhou🇨🇳

    In this paper, we present an improved analysis of the top-quark pair production via the process $e^{+}{e}^{-}\to {\gamma }^{\ast }\to t\bar{t}$ near the threshold region up to next-to-next-to-next-to-leading order (N${}^3$LO) QCD corrections. Near the threshold region, the top-quark velocity $v$ tends to zero, leading to Coulomb singularity. To achieve a reasonable prediction in the threshold region, we reconstruct the analytical expression for the Coulomb-terms up to N${}^3$LO accuracy by using the PSLQ algorithm, whose numerical values agree well with the previous N${}^3$LO-level calculations. It is found that the N${}^3$LO series still has sizable renormalization scale dependence, and to improve the precision of the series, we apply the Principle of Maximum Conformality to eliminate such scale dependence. After that, the Coulomb part is resummed into a Sommerfeld-Gamow-Sakharov factor, which finally leads to a much more reasonable behavior near the threshold region.

    hep-phPLB(2024)·8 citations
13. 13*

    Phenomenological study of the angle between jet axes in heavy-ion collisions

    Jin-Wen Kang🇨🇳 · Sa Wang🇨🇳 · Lei Wang🇨🇳 · Ben-Wei Zhang🇨🇳

    This paper presents a phenomenological study on the angle between the Standard and the Winner-Take-All (WTA) jet axes ($\Delta R_{\mathrm{axis}}^{\mathrm{WTA}-\mathrm{Std}}$) in high-energy nuclear collisions. The $p$+$p$ baseline is provided by the Pythia8 event generator. The in-medium jet propagation is simulated by the linear Boltzmann transport (LBT) model, which considers both the elastic and inelastic jet-medium interactions. Our theoretical results calculated by the LBT model show that the $\Delta R_{\mathrm{axis}}^{\mathrm{WTA}-\mathrm{Std}}$ distribution in Pb+Pb at $\sqrt{s}=5.02$ TeV is narrower than that in $p$+$p$, which agrees well with the recent ALICE measurements. The narrowing of $\Delta R_{\mathrm{axis}}^{\mathrm{WTA}-\mathrm{Std}}$ seems to violate the $p_T$-broadening nature of the jet quenching effect, usually explained by the influence of "selection bias". However, the physical details still need to be fully understood. Utilizing a matching-jet method to track the jet evolution in the QGP to remove the selection bias in the Monte Carlo simulations, we observe that the $\Delta R_{\mathrm{axis}}^{\mathrm{WTA}-\mathrm{Std}}$ distribution becomes broader due to the jet-medium interactions. At the same time, by rescaling the quark/gluon-jet fractions in Pb+Pb collisions to be the same as that in $p$+$p$, we find that the fraction change may not significantly influence the modification pattern of jet $\Delta R_{\mathrm{axis}}^{\mathrm{WTA}-\mathrm{Std}}$. On the other hand, the selected jet sample in A+A collisions has a significantly narrower initial $\Delta R_{\mathrm{axis}}^{\mathrm{WTA}-\mathrm{Std}}$ distribution than the $p$+$p$ baseline, and such a biased comparison between $p$+$p$ and A+A conceals the actual jet-broadening effect in the experimental measurements. The investigations presented in this paper will deepen our understanding of the relationship between the actual intra-jet modifications in the QGP and the experimental observations.

    hep-phhep-exnucl-thPRC(2025)·8 citations
14. 14*

    The $z_g$ distribution for heavy flavour jets in dense quark-gluon plasma

    Boris Blok (Technion)🇮🇱 · Chang Wu (Technion)🇮🇱

    We study the $z_g$ distribution for heavy flavour, i.e. bottom and charm quark, jets propagating through the dense QCD medium. We extend the late emission approximation for Armesto-Salgado-Wiedemann (ASW) formula to heavy flavours. % We consider both the normalised and $N_{\mathrm{jet}}$ normalised $z_g$ distributions, and the ratio of the latter distributions to the vacuum ones, called the R ratio. We demonstrate that since there is no collinear singularity in the medium, there is no principal need to use the Sudakov safety technique for medium-induced emission (MIE). We see that contrary to the vacuum case, the normalised $z_g$ distribution is sensitive to the dead cone angle value. In particular, for the case of $N_{jet}$ normalised distribution with ${\theta }_g\le {\theta }_{cut}$, it is possible to directly probe the dead cone gluons in the medium. Our results can be useful to guide the experimental measurements of the heavy flavour jet substructure in dense QCD medium.

    hep-phhep-exnucl-exnucl-thPRD(2025)·6 citations
15. 15*

    Thermal Relic Right-Handed Neutrino Dark Matter

    Yu Cheng🇨🇳 · Jie Sheng🇨🇳 · Tsutomu T. Yanagida🇨🇳

    It is known that two heavy Majorana right-handed neutrinos are sufficient to generate the baryon asymmetry in the present universe. Thus, it is interesting to identify the third right-handed neutrino $N$ with the dark matter. We impose a new discrete symmetry $Z_2$ on this dark matter neutrino to stabilize it. However, the $U(1{)}_{B-L}$ gauge boson $A^{\prime }$ couples to the right-handed neutrino $N$. If the $B-L$ breaking scale $V_{B-L}$ is sufficiently low, the dark matter neutrino $N$ can be in the thermal bath. We find that the thermal relic $N$ can explain the dark matter abundance for the $B-L$ breaking scale $V_{B-L}\sim O(10)$TeV. After considering all the constraints from the existing experiments, a narrow mass region of the thermal produced right-handed neutrino dark matter $N$ is still surviving.

    hep-phPLB(2024)·5 citations
16. 16*

    Revisiting Metastable Cosmic String Breaking

    Akifumi Chitose🇯🇵 · Masahiro Ibe🇯🇵 · Yuhei Nakayama🇯🇵 · Satoshi Shirai🇯🇵 · Keiichi Watanabe🇯🇵

    Metastable cosmic strings appear in models of new physics with a two-step symmetry breaking $G\to H\to 1$, where ${\pi }_1(H)\ne 0$ and ${\pi }_1(G)=0$. They decay via the monopole-antimonopole pair creation inside. Conventionally, the breaking rate has been estimated by an infinitely thin string approximation, which requires a large hierarchy between the symmetry breaking scales. In this paper, we reexamine it by taking into account the finite sizes of both the cosmic string and the monopole. We obtain a robust lower limit on the tunneling factor $e^{-S_B}$ even for regimes the conventional estimate is unreliable. In particular, it is relevant to the cosmic string interpretation of the gravitational wave signals recently reported by pulsar timing array experiments.

    hep-phastro-ph.COhep-thJHEP(2024)·26 citations
17. 17*

    Probing scalar, Dirac, Majorana and vector DM through spin-0 electron-specific mediator at the electron fixed-target experiments

    I. V. Voronchikhin🇷🇺 · D. V. Kirpichnikov🇷🇺

    We discuss the thermal target curves of Majorana, Dirac, scalar and vector light dark matter (DM) that are associated with the freeze-out mechanism via the annihilation into $e^{+}{e}^{-}$ pair through the electron-specific spin-0 mediator of dark matter. We also discuss the mechanism to produce the regarding DM mediator in the electron (positron) fixed-target experiments such as NA64e and LDMX. We derive the corresponding experimental reaches of the NA64e and LDMX that are complementary to the DM thermal target parameter space.

    hep-phPRD(2024)·4 citations
18. 18*

    Dark matter production accompanied by gravitational wave signals during cosmological phase transitions

    Shuocheng Xu🇨🇳 · Ruiyu Zhou🇨🇳 · Wei Cheng🇨🇳 · Xuewen Liu🇨🇳

    We investigate the temperature-dependent production of feebly interacting massive dark matter particle (FIMP DM) within a $Z_2$ model, incorporating two $Z_2$-odd scalar fields. In specific parameter regions, three distinct mechanisms individually dominate the production of the FIMP DM. These mechanisms include the semi-production process, commonly known as the ``exponential growth'' process, the production from pair annihilations of the bath particles, and the three-body decay process. It is crucial to consider the thermal history during the evolution of FIMPs, as it involves multiple phase transitions occurring prior to the freeze-in of dark matter. Consequently, the scalar masses experience thermal variations, leading to a distinctive evolutionary trajectory for FIMPs when compared to scenarios without accounting for the thermal effects. Notably, the unique pattern of FIMP evolution is accompanied by the production of gravitational waves, presenting promising opportunities for detection using forthcoming interferometers.

    hep-phEPJC(2024)·4 citations
19. 19*

    Present and future of CosmoLattice

    Daniel G. Figueroa🇪🇸 · Adrien Florio🇺🇸 · Francisco Torrenti🇪🇸

    We discuss the present state and planned updates of CosmoLattice, a cutting-edge code for lattice simulations of non-linear dynamics of scalar-gauge field theories in an expanding background. We first review current capabilities of the code, including the simulation of interacting singlet scalars and of Abelian and non-Abelian scalar-gauge theories. We also comment on new features recently implemented, such as the simulation of gravitational waves from scalar and gauge fields. Secondly, we discuss new extensions of CosmoLattice that we plan to release publicly. On the one hand, we comment on new physics modules, which include axion-gauge interactions $\varphi F\tilde{F}$, non-minimal gravitational couplings ${\varphi }^{2}R$, creation and evolution of cosmic defect networks, and magneto-hydro-dynamics (MHD). On the other hand, we discuss new technical features, including evolvers for non-canonical interactions, arbitrary initial conditions, simulations in 2+1 dimensions, and higher accuracy spatial derivatives.

    ↳ astro-ph.COgr-qchep-lathep-ph+1Rept.Prog.Phys.(2024)·21 citations
20. 20*

    Feeding plankton to whales: high-redshift supermassive black holes from tiny black hole explosions

    Yifan Lu🇺🇸 · Zachary S. C. Picker🇺🇸 · Alexander Kusenko🇺🇸

    Recent observations of the high-redshift universe have uncovered a significant number of active galactic nuclei, implying that supermassive black holes (SMBHs) would have to have been formed at much earlier times than expected. Direct collapse of metal-free gas clouds to SMBHs after recombination could help explain the early formation of SMBHs, but this scenario is stymied by the fragmentation of the clouds due to efficient molecular hydrogen cooling. We show that a subdominant population of tiny, evaporating primordial black holes, with significant clustering in some gas clouds, can heat the gas sufficiently so that molecular hydrogen is not formed, and direct collapse to to black holes is possible even at high redshifts.

    ↳ astro-ph.GAastro-ph.COhep-phPRD(2024)·19 citations
21. 21*

    Cosmological constraints from combined probes with the three-point statistics of galaxies at one-loop precision

    Simon Spaar🇨🇭 · Pierre Zhang🇨🇭

    We present cosmological constraints from a joint analysis including the power spectrum and bispectrum of BOSS galaxies based on the Effective Field Theory of Large-Scale Structure predictions at one-loop order, in combination with CMB data from Planck, Supernovae from Pantheon+, and BAO from eBOSS and 6dF/MGS. Limits on $\Lambda$CDM parameters are in good agreement, and on average $\sim 5-10\%$ tighter, compared to former results including similar datasets but no bispectrum. Moreover, we find that galaxies at the three-point level with one-loop precision are decisive for the dark energy equation of state, constrained to be $w=-0.975\pm 0.019$ at $68\%$CL. This value, consistent at $\sim 1.3\sigma$ with a cosmological constant, represents an improvement of about $140\%$ with respect to former determination. Our analyses illustrate the importance of beyond-two-point statistics at the highest reachable scales in constraining cosmological parameters, and in particular departure from $\Lambda$CDM.

    ↳ astro-ph.COhep-phhep-thPRD(2025)·15 citations
22. 22*

    Mass and Isospin Breaking Effects in the Skyrme Model and in Holographic QCD

    Lorenzo Bartolini🇨🇳 · Stefano Bolognesi🇮🇹 · Sven Bjarke Gudnason🇨🇳 · Tommaso Rainaldi🇺🇸

    We discuss how the quark masses and their mass splitting affect the baryons in the Skyrme model as well as the Witten-Sakai-Sugimoto (WSS) model. In both cases baryons are described by solitonic objects, i.e. Skyrmions and instantons, respectively. After the quantization of their zeromodes the nucleons become quantum states of a rotor. We show how the quark mass affects the moment of inertia and we provide a semi-analytic approach valid in the small-mass limit. Additionally, we show how the two lightest quarks' mass splitting affects the moments of inertia of the Skyrmion and induces an isospin breaking effect. This effect turns out not to be enough to split the degeneracy in the neutron-proton multiplet, but it splits some of the states in the Delta multiplet. Unlike the basic Skyrme model, the WSS model already includes vector mesons and another mechanism to transfer isospin breaking from quark masses to the solitons is known. We compute the splitting of the moment of inertia in the small-mass limit in the WSS model and combine the two effects on the spectrum of baryons, in particular the Deltas.

    ↳ hep-thhep-phPRD(2024)·4 citations
23. 23*

    Constraints on sterile neutrinos and the cosmological tensions

    Supriya Pan🇮🇳 · Osamu Seto🇯🇵 · Tomo Takahashi🇯🇵 · Yo Toda🇯🇵

    We investigate cosmological bounds on sterile neutrino masses in the light of the Hubble and $S_8$ tensions. We argue that non-zero masses for sterile neutrinos are inferred at 2$\sigma$ level in some extended models such as varying dark energy equation of state, when a direct measurement of the Hubble constant $H_0$ and weak lensing measurement of dark energy survey (DES) are taken into account. Furthermore, the Hubble and $S_8$ tensions are also reduced in such a framework. We also consider the case where a non-flat Universe is allowed and show that a slightly open Universe may be favored in models with sterile neutrinos in the context of the cosmological tensions.

    ↳ astro-ph.COhep-phPRD(2024)·18 citations
24. 24*

    Sphaleron rate as an inverse problem: a novel lattice approach

    Claudio Bonanno🇪🇸 · Francesco D'Angelo🇮🇹 · Massimo D'Elia🇮🇹 · Lorenzo Maio🇮🇹 · Manuel Naviglio🇮🇹

    We compute the sphaleron rate on the lattice. We adopt a novel strategy based on the extraction of the spectral density via a modified version of the Backus-Gilbert method from finite-lattice-spacing and finite-smoothing-radius Euclidean topological charge density correlators. The physical sphaleron rate is computed by performing controlled continuum limit and zero-smoothing extrapolations both in pure gauge and, for the first time, in full QCD.

    ↳ hep-lathep-phPoS(2024)·3 citations
25. 25*

    Observational constraints on extended Proca-Nuevo gravity and cosmology

    Fotios K. Anagnostopoulos🇬🇷 · Emanuel N. Saridakis🇬🇷

    We confront massive Proca-Nuevo gravity with cosmological observations. The former is a non-linear theory involving a massive spin-1 field, that can be extended incorporating operators of the Generalized Proca class, and when coupled to gravity it can be covariantized in a way that exhibits consistent and ghost-free cosmological solutions, without experiencing instabilities and superluminalities at the perturbative level. When applied at a cosmological framework it induces extra terms in the Friedmann equations, however due to the special non-linear construction the field is eliminated in favor of the Hubble function. Thus, the resulting effective dark energy sector is dynamical, however it contains the same number of free parameters with the $\Lambda$CDM concordance model. We use data from Supernovae Ia (SNIa) and Cosmic Chronometers (CC) observations and we construct the corresponding likelihood-contours for the free parameters. Interestingly enough, application of various information criteria, such as AIC, BIC and DIC, shows that the scenario of massive Proca-Nuevo gravity, although having exactly the same number of free parameters with $\Lambda$CDM paradigm, it is more efficient in fitting the data. Finally, the reconstructed dark-energy equation-of-state parameter shows statistical compatibility with the model-independent, data-driven reconstructed one.

    ↳ astro-ph.COgr-qchep-phJCAP(2024)·8 citations
26. 26*

    The imprint of conservation laws on correlated particle production

    Peter Braun-Munzinger🇩🇪 · Krzysztof Redlich🇵🇱 · Anar Rustamov🇩🇪 · Johanna Stachel🇩🇪

    The study of event-by-event fluctuations of net-baryon number in a subspace of full phase space is a promising direction for deciphering the structure of strongly interacting matter created in head-on collisions of relativistic heavy nuclei. Such fluctuations are generally suppressed by exact baryon number conservation. Moreover, the suppression is stronger if baryon number is conserved locally. In this report we present a conceptually new approach to quantify correlations in rapidity space between baryon-antibaryon, baryon-baryon, and antibaryon-antibaryon pairs and demonstrate their impact on net-baryon number fluctuations. For the special case of Gaussian rapidity distributions, we use the Cholesky factorization of the covariance matrix, while the general case is introduced by exploiting the well-known Metropolis and Simulated Annealing methods. The approach is based on the use of the canonical ensemble of statistical mechanics for baryon number and can be applied to study correlations between baryons as well as strange and/or charm hadrons. It can also be applied to describe relativistic nuclear collisions leading to the production of multi-particle final states. One application of our method is the search for formation of proton clusters at low collision energies emerging as a harbinger of the anticipated first-order chiral phase transition. In a first step, the results obtained are compared to the recent measurements from the CERN ALICE collaboration. Such investigations are key to explore the phase diagram of strongly interacting matter and baryon production mechanisms at energy scales from several GeV to several TeV.

    ↳ nucl-thhep-phnucl-exJHEP(2024)·25 citations
27. 27*

    Measurements of ${\Lambda }_{\mathrm{c}}^{+}/{\mathrm{D}}^0$ ratio as a function of multiplicity at midrapidity at $\sqrt{s_{\text{NN}}}=5.02\text{TeV}$

    Oveis Sheibani (on behalf of ALICE collaboration)🇺🇸

    In this contribution, the measurement of prompt ${\Lambda }_{\mathrm{c}}^{+}/{\mathrm{D}}^0$ ratio as a function of multiplicity in p--Pb collisions at mid-rapidity at $\sqrt{s_{\text{NN}}}=5.02\text{TeV}$ is discussed. By performing this measurement as a function of multiplicity in pp and p--Pb collisions, we can evaluate the $p_{\mathrm{T}}$-differential baryon to meson enhancement and compare them to results in ${\mathrm{e}}^{-}{\mathrm{e}}^{+}$ and ${\mathrm{e}}^{-}\mathrm{p}$ collisions, where lower ${\Lambda }_{\mathrm{c}}^{+}/{\mathrm{D}}^0$ ratios at low and intermediate $p_{\mathrm{T}}$ have been observed, with the origin of this different behavior being still debated. In these measurements, we aim to compare the p--Pb results to pp collisions to investigate the possible effects of cold nuclear matter on charm-baryon production, and to Pb--Pb collisions for investigating the impact of quark--gluon plasma on charm quark hadronization.

    ↳ nucl-exhep-exhep-ph2 citations
28. 28*

    Saturation of nuclear matter in the relativistic Brueckner Hatree-Fock approach with a leading order covariant chiral nuclear force

    Wei-Jiang Zou🇨🇳 · Jun-Xu Lu🇨🇳 · Peng-Wei Zhao🇨🇳 · Li-Sheng Geng🇨🇳 · Jie Meng🇨🇳

    Nuclear saturation is a crucial feature in nuclear physics that plays a fundamental role in understanding various nuclear phenomena, ranging from properties of finite nuclei to those of neutron stars. However, a proper description of nuclear saturation is highly nontrivial in modern nonrelativistic~\textit{ab initio}~studies because of the elusive three-body forces. In this letter, we calculate the equation of state for nuclear matter in the relativistic Brueckner-Hartree-Fock (RBHF) framework with the leading order covariant chiral nuclear force. We show that a simultaneous description of the nucleon-nucleon scattering data and the saturation of the symmetric nuclear matter can be achieved. In this regard, the relativistic effects nicely explain the saturation of nuclear matter. As a result, the present study based on the covariant chiral nuclear force shows that in the RBHF framework, one can achieve saturation with a leading order covariant chiral nuclear force with only two-body forces, in contrast to the vast majorities of studies in the non-relativistic framework, where the next-to-next-to-leading order two-body and three-body chiral forces are needed. This study sets the foundation for studying nuclear saturation with the covariant chiral force in the RBHF framework, which allows for a systematic understanding of one of the key features of nuclear physics more microscopically.

    ↳ nucl-thhep-phnucl-exPLB(2024)·18 citations
29. 29*

    Probing Gauss-Bonnet-Corrected Inflation with Gravitational Waves

    Kamil Mudrunka🇨🇿 · Kazunori Nakayama🇯🇵

    The low energy effective action of quantum gravity may include the higher curvature terms such as the Gauss-Bonnet term. The inflaton dynamics may be affected by the Gauss-Bonnet term if there is an inflaton-Gauss-Bonnet coupling. We show that an inflation model with a simple power law potential is made viable if it is coupled to the Gauss-Bonnet term since the prediction on the scalar spectral index and the tensor-to-scalar ratio are modified. We further point out that such a model predicts huge amount of gravitational waves at the high frequency range around 100GHz--100THz through the perturbative inflaton decay into gravitons induced by the Gauss-Bonnet term. Thus the spectrum of high frequency gravitational background is a unique feature of the inflation models with a Gauss-Bonnet correction.

    ↳ astro-ph.COgr-qchep-phJCAP(2024)·10 citations
30. 30*

    Time Scales in Many-Body Fast Neutrino Flavor Conversion

    Ramya Bhaskar🇺🇸 · Alessandro Roggero🇮🇹 · Martin J. Savage🇺🇸

    Time scales associated with many-body fast neutrino flavor conversions in core-collapse supernova are explored in the context of an effective two-flavor model with axial symmetry. We present a preliminary study of time scales obtained from a linear stability analysis and from the distributions of Loschmidt echo crossing times (intimately connected to dynamical phase transitions in non-equilibrium systems) determined by time evolution with the exact many-body Hamiltonian. Starting from a tensor-product initial state describing systems of $N$ neutrinos, with $N/2$ electron-type and $N/2$ heavy-type, with uniform angular distributions, the Loschmidt echo crossing times, $t_{{\mathcal{L}}_{\times }}$, are found to exhibit two distinct time scales that are exponentially separated. The second peak structure at longer times, effectively absent for $N=4$, develops with increasing $N$. When re-scaled in terms of $\log t_{{\mathcal{L}}_{\times }}$, the distributions are found to become increasingly well described by the sum of two stable distributions. The distribution of Loschmidt echo crossing times differs somewhat from the results of the (numerical) linear stability analysis, which exhibits a peak at finite frequency and a second peak consistent with zero frequency. The exact analysis suggests that the zero-frequency instability manifests itself as a modest flavor-conversion time scale.

    ↳ nucl-thhep-ph8 citations
31. 31*

    Recent developments from Feynman integrals

    Robin Marzucca🇨🇭 · Andrew J. McLeod🇬🇧 · Ben Page🇨🇭 · Sebastian Pögel🇩🇪 · Xing Wang🇩🇪 · Stefan Weinzierl🇩🇪

    This talk reviews recent developments in the field of analytical Feynman integral calculations. The central theme is the geometry associated to a given Feynman integral. In the simplest case this is a complex curve of genus zero (aka the Riemann sphere). In this talk we discuss Feynman integrals related to more complicated geometries like curves of higher genus or manifolds of higher dimensions. In the latter case we encounter Calabi-Yau manifolds. We also discuss how to compute these Feynman integrals.

    ↳ hep-thhep-phActa Phys.Polon.Supp.(2024)·2 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.