Fri·Mar 1, 2024Friday·March 1, 2024

1. 01*

   QCD at Finite Temperature and Density -- Equation of State

   Jamie M. Karthein🇺🇸

   As an important set of thermodynamic quantities, knowledge of the equation of state over a broad range of temperatures and chemical potentials in the QCD phase diagram is crucial for our understanding of strongly-interacting matter. There is a good understanding from first-principles results in lattice QCD, perturbative QCD and chiral effective field theory about the equation of state. However, these approaches are valid in different regimes of the phase diagram, and therefore, a method of providing an equation of state that covers a full range of the phase diagram involves matching together these results with appropriate models in order to fill in the gaps between these regions. Furthermore, with such equations of state, important questions about QCD phase structure can begin to be addressed, such as whether there is a critical point in the QCD phase diagram. In this contribution to the proceedings, equations of state from first-principles and effective theories will be discussed in order to understand how QCD thermodynamics is affected by the presence of a critical point.

   hep-phnucl-thEPJ Web Conf.(2024)·1 citation
2. 02*

   B-mesons as essential probes of hot QCD matter

   Vinod Chandra🇮🇳 · Santosh K. Das🇮🇳

   This article elucidates the pivotal role of b-mesons and bottomonium states in exploring the existence and properties of hot QCD matter (commonly known as quark-gluon-plasma (QGP) produced within the crucible heavy-ion collision experiments). Owing to the complex and confounding nature of strong interaction force the direct detection of probing the hot QCD matter is not feasible. In light of this, investigating the dynamics of b-quarks and anti-quarks within the hot QCD medium emerges as an invaluable indirect probe. The impact of b-quarks and the mesons spans a spectrum of interesting domains regarding the physics of QCD at finite temperature, encompassing the QCD phase transition, color screening, quarkonia dissociation, heavy quark energy loss and collective flow, anisotropic aspects, and strongly coupled nature of hot QCD medium. These aspects underscore the indispensable nature of B-mesons in the quest to create and explore the complex nature of strong interaction force through the QGP/hot QCD matter. In this context, we mainly focus on works related to transport studies of b-mesons in hot QCD medium, lattice QCD, and effective field theory studies on bottomonium states, and finally, open quantum system frameworks to quarkonia to explore the properties of hot QCD medium in relativistic heavy-ion collision experiments.

   hep-phnucl-thEur.Phys.J.ST(2024)·7 citations
3. 03*

   Beauty-charm Meson Family with Coupled Channel Effects and Their Strong Decays

   Wei Hao🇨🇳 · Ruilin Zhu🇨🇳

   We systematically study the mass spectra and their two-body hadronic decays of the beauty-charm meson family considering the coupled channel effects. Our results can good explain the observed $B_c$ meson spectrum and the prediction of the mass spectrum for unobserved beauty-charm mesons can be tested in future experiments. For the coupled channel components, we predicted the $1S$ state in beauty-charm meson family is about $4\%$, while the $2S$, $1P$, $2P$, $1D$, and $2D$ states are about $14\%$, $10\%$, $33\%$, and $17\%$ respectively. For the $3S$, $2P$ and $2D$ states, the strong decay is allowed, The two-body hadronic decay widths of the $3^1{S}_0$, $3^3{S}_1$, $2^3{P}_2$ states are about 110 MeV, 69 MeV, and 3 MeV, respectively. While the two-body decay widths of the $2^3{D}_1$, $2D$, $2D^{\prime }$, and $2^3{D}_2$ states are 60 MeV, 149 MeV, 65 MeV, and 72 MeV, respectively.

   hep-phCPC(2024)·11 citations
4. 04*

   Electromagnetic properties of ${\Omega }_c^0$ resonances via light-cone QCD

   U. Özdem🇹🇷

   We systematically study the electromagnetic properties of controversial states whose internal structure is not elucidated and we try to offer a different point of view to unravel the internal structure of these states. Inspired by the ${\Omega }_c$ states observed by the LHCb Collaboration, we study the electromagnetic properties of the ${\Omega }_c$ states as the compact diquark-diquark-antiquark pentaquarks with both $J^P={\frac{1}{2}}^{-}$ and $J^P={\frac{3}{2}}^{-}$ in the context of the QCD light-cone sum rule model. From the obtained numerical results, we conclude that the magnetic dipole moments of the ${\Omega }_c$ states can reflect their inner structures, which can be used to distinguish their spin-parity quantum numbers. Measuring the magnetic moment of the ${\Omega }_c$ states in future experimental facilities can be very helpful for understanding the internal organization and identifying the quantum numbers of these states.

   hep-phhep-exhep-latEur.Phys.J.Plus(2024)·4 citations
5. 05*

   Neutrino Mixing and Resonant Leptogenesis in Inverse Seesaw and {\Delta}(54) Flavor Symmetry

   Hrishi Bora🇮🇳 · Ng. K. Francis🇮🇳 · Bikash Thapa🇮🇳 · Shawan Kumar Jha🇮🇳

   The current work involves augmenting the $\Delta (54)$ discrete flavor model by incorporating two Standard Model Higgs particles into the Inverse Seesaw mechanism. We introduced Weyl fermions and Vector like fermions, which are gauge singlets in the Standard Model and produces Majorana mass terms in our lagrangian. The resulting mass matrix deviates from the tribimaximal neutrino mixing pattern producing a non-zero reactor angle (${\theta }_{13}$) . We have determined the effective Majorana neutrino mass, which is the parameter of relevance in neutrinoless double beta decay investigations, using the model's limited six-dimensional parameter space. We additionally investigate the possibility of baryogenesis in the proposed framework via resonant leptogenesis. We have the non-zero value for resonantly enhanced CP asymmetry originating from the decay of right-handed neutrinos at the TeV scale, accounting for flavor effects. The evolution of lepton asymmetry is systematically analyzed by numerically solving a set of Boltzmann equations, leading to the determination of the baryon asymmetry with a magnitude of $|{\eta }_B|\approx 6\times 10^{-10}$. This outcome is achieved by selecting specific values for the right-handed neutrino mass $M_1=10$ TeV and mass splitting, $d\approx 10^{-8}$.

   hep-phJHEP(2026)·0 citations
6. 06*

   Light quarkonium hybrid mesons

   B. Barsbay🇹🇷 · K. Azizi🇮🇷 · H. Sundu🇹🇷

   We investigate the light quarkonium hybrid mesons of various spin-parities in QCD. Considering different interpolating currents made of the valence light quarks and single gluon, we calculate the mass and current coupling of the strange and nonstrange members of light hybrid mesons by including into computations the nonperturbative quark and gluon condensates up to ten dimensions in order to increase the accuracy of the results. The obtained results may be useful for future experimental searches of these hypothetical states. They can also be used in the calculations of different parameters related to the decays/interactions of light hybrid mesons to/with other states.

   hep-phhep-exhep-latPRD(2024)·15 citations
7. 07*

   Nuclear medium meson structures from the Schwinger proper-time Nambu--Jona-Lasinio model

   Geoffry Gifari🇮🇩 · Parada T. P. Hutauruk🇰🇷 · Terry Mart🇮🇩

   In this paper, we report the results of our study on the nuclear medium modifications of the meson electromagnetic form factors in the framework of the Nambu--Jona-Lasinio (NJL) model with the help of the Schwinger proper-time regularization scheme to tame the loop divergence and simulate the effect of QCD confinement. In our current approach, the meson structure and nuclear medium are constructed in the same NJL model at the quark level. We examine the free-space and in-medium charge radii of kaon and pion, the spacelike elastic electromagnetic form factors of kaon and pion, and their quark-sector form factors, which reflect their internal structures. By comparing our result to experimental data, we found that the free-space elastic electromagnetic form factors of the mesons are consistent with the data, while the in-medium elastic electromagnetic form factors of the mesons are found to decrease as the nuclear matter density increases, leading to a rise of meson charge radius, which is consistent with the prediction of other theoretical calculations. We also predict the axial nucleon coupling constant $g_A$ in nuclear medium computed via the Goldberger-Treiman relation (GTR), which is crucial for searching the neutrinoless double beta decay ($0\nu \beta \beta$).

   hep-phnucl-thPRD(2024)·17 citations
8. 08*

   Slicing Pomerons in ultraperipheral collisions using forward neutrons from nuclear breakup

   M. Alvioli (CNR IRPI, Perugia and INFN, Perugia)🇮🇹 · V. Guzey (Jyvaskyla U. and Helsinki Inst. of Phys.)🇫🇮 · M. Strikman (Penn State U.)🇺🇸

   We argue that measurements of forward neutrons from nuclear breakup in inclusive high energy photon-nucleus ($\gamma A$) scattering provide a novel way to study small-$x$ dynamics of QCD in heavy-ion ultraperipheral collisions (UPCs). Using models for hadronic fluctuations of the real photon and neutron emission in nuclear fragmentation, we calculate the distribution over the number of evaporation neutrons produced in $\gamma Pb$ collisions at the LHC. We show that it is correlated with the number of wounded nucleons (inelastic collisions) and, hence, can constrain the mechanism of nuclear shadowing and its $x$ dependence.

   hep-phhep-exnucl-exPRC(2024)·9 citations
9. 09*

   Cosmic Inflation, Dark Energy and Gravitational Waves

   Konstantinos Dimopoulos🇬🇧

   We briefly discuss cosmic inflation, which is the dominant paradigm for the generation of the large scale structure in the Universe and also for arranging for the initial conditions of the hot Big Bang. We then present quintessential inflation, which also accounts of the observed dark energy. We discuss how quintessential inflation can be successfully modelled in modified gravity in the Palatini formalism. Finally, we focus on the generation of primordial gravitational waves by inflation and how their spectrum can be enhanced when the early Universe goes through periods of stiff equation of state. This results in gravitational waves with a characteristic spectrum, which may well be observed in the near future, providing insights for the background theory.

   hep-phMoscow Univ.Phys.Bull.(2024)·0 citations
10. 10*

    Features of strangeness production in pp and heavy ion collisions

    A. Pop🇷🇴 · M. Petrovici🇷🇴

    Based on the existing experimental data for A-A collisions starting from the AGS energies up to the LHC ones, various systematics related to strange hadrons and anti-hadrons are presented. The ratio between the average transverse momentum and the square root of the total particle multiplicity per unit rapidity and unit transverse overlap area decreases with collision energy for a given centrality or with centrality for a given collision energy, thus supporting the predictions of CGC and percolation based approaches. The dependence on the square root of the total multiplicity per unit rapidity and unit transverse overlap area of the slope and offset extracted from the $⟨p_T⟩$-particle mass correlation and of the average transverse expansion velocity and kinetic freeze-out temperature parameters obtained from BGBW fits of the pT spectra for strange hadrons is compared to that for pions, kaons and protons. The detailed study of the entropy density dependence of the ratio of strange hadron yields per unit rapidity to the total particle multiplicity per unit rapidity, at different collision energies and centralities, reveals the necessity to study separately strange hadrons and anti-hadrons. The correlation between the ratio of the single- and multi- strange anti-hadron yield per unit rapidity to the total particle multiplicity per unit rapidity and the entropy density is presented as a function of the fireball size. A maximum is evidenced in the similar correlation established for combined and separate species of strange hadrons, at different centralities, in the region where a transition from the baryon-dominated matter to the meson-dominated one takes place. The position of this maximum does not depend on the mass of the corresponding strange hadron. Comparison with pp experimental data reveals another similarity between pp and Pb-Pb collisions at the LHC energies.

    hep-phPRC(2025)·1 citation
11. 11*

    Charged Lepton Flavor Violation in the B-L symmetric SSM

    Xing-Xing Dong🇨🇳 · Shu-Min Zhao🇨🇳 · Jia-Peng Huo🇨🇳 · Tong-Tong Wang🇨🇳 · Tai-Fu Feng🇨🇳

    Charged lepton flavor violation (CLFV) represents a clear new physics (NP) signal beyond the standard model (SM). In this work, we investigate CLFV processes $l_j^{-}\to l_i^{-}\gamma$ utilizing mass insertion approximation(MIA) in the minimal supersymmetric extension of the SM with local B-L gauge symmetry (B-LSSM). The MIA method can provide a set of simple analytic formulae for the form factors and the associated effective vertices, so that the movement of the CLFV decays $l_j^{-}\to l_i^{-}\gamma$ with the sensitive parameters will be intuitively analyzed. Considering the SM-like Higgs boson mass and the muon anomalous dipole moment (MDM) within $4\sigma$, $3\sigma$ and $2\sigma$ regions, we discuss the corresponding constraints on the relevant parameter space of the model.

    hep-phPRD(2024)·6 citations
12. 12*

    Photon-Odderon interference in exclusive ${\chi }_c$ charmonium production at the Electron-Ion Collider

    Sanjin Benić🇭🇷 · Adrian Dumitru🇺🇸 · Abhiram Kaushik🇭🇷 · Leszek Motyka🇵🇱 · Tomasz Stebel🇵🇱

    Exclusive $C=+1$ scalar, axial-vector, and tensor quarkonium production in high-energy electron-proton scattering requires a $C$-odd $t$-channel exchange of a photon or a three gluon ladder. We derive the expressions for the corresponding amplitudes. The relative phase of the photon vs. three gluon exchange amplitudes is determined by the sign of the light-front matrix element of the eikonal color current operator $d^{abc}{J}^{+a}{J}^{+b}{J}^{+c}$ at moderate $x$, and is not affected by small-$x$ QCD evolution. Model calculations predict constructive interference, which is particularly strong for momentum transfer $|t|\sim 1$~GeV${}^2$ where the cross section for ${\chi }_{cJ}$ production exceeds that for pure photon exchange by up to a factor of 4. We find that exclusive ${\chi }_{cJ}$ electroproduction at the Electron-Ion Collider should occur with well measurable rates and measurements of these processes should allow to find an evidence of the perturbative Odderon exchange. We also compute the total electroproduction cross section as a function of energy and provide first estimates of the number of ${\chi }_{cJ}$ events per month at the Electron-Ion Collider design luminosity.

    hep-phPRD(2024)·19 citations
13. 13*

    Study of Long Range Force in P2SO and T2HKK

    Priya Mishra🇮🇳 · Rudra Majhi🇮🇳 · Sambit Kumar Pusty🇮🇳 · Monojit Ghosh🇭🇷 · Rukmani Mohanta🇮🇳

    In this paper we have studied the sensitivity of the future long-baseline neutrino experiments P2SO and T2HKK to the long-range force (LRF). In the context of these two experiments, our aim is to study: (i) the capability to put bounds on the LRF parameters, (ii) effect of LRF in the measurement of standard oscillation parameters and (iii) capability to constrain the mass of the new gauge boson and the value of new coupling constant, that gives rise to LRF due to matter density in Sun. In our study, we find that among the different neutrino experiments, the best bound on the LRF parameters including mass of the new gauge boson and the value of new coupling constant will come from the P2SO experiment. Our study also shows that LRF has non-trivial effect on the determination of the standard neutrino oscillation parameters except the precision of $\Delta m_{31}^2$. For this parameter, the precision remains unaltered in the presence of LRF for both these experiments.

    hep-phJHEP(2024)·7 citations
14. 14*

    Magnetic catalysis and diamagnetism from pion fluctuations

    Jie Mei🇨🇳 · Rui Wen🇨🇳 · Shijun Mao🇨🇳 · Mei Huang🇨🇳 · Kun Xu🇨🇳

    In the framework of Nambu--Jona-Lasinio model beyond mean field approximation, the effects of pion fluctuations on (inverse) magnetic catalysis and magnetic susceptibility are studied. The negative magnetic susceptibility at low temperature is observed when contributions from both neutral and charged pions are taken into account. In weak field approximation, it is observed that at finite temperature, the magnetic inhibition effect in the chiral limit, resulting from the difference between the transverse and longitudinal velocities of neutral pions, converts to weak magnetic catalysis when considering a non-zero current quark mass. Moreover, the magnetic catalysis is amplified by the charged pions.

    hep-phPRD(2024)·18 citations
15. 15*

    Deciphering the Belle II data on $B\to K\nu \bar{\nu }$ decay in the (dark) SMEFT with minimal flavour violation

    Biao-Feng Hou🇨🇳 · Xin-Qiang Li🇨🇳 · Meng Shen🇨🇳 · Ya-Dong Yang🇨🇳 · Xing-Bo Yuan🇨🇳

    Recently, the Belle II collaboration announced the first measurement of $\mathcal{B}(B^{+}\to K^{+}\nu \bar{\nu })$, which is found to be about $2.7\sigma$ higher than the SM prediction. We decipher the data with two new physics scenarios: the underlying $b\to s\nu \bar{\nu }$ transition is, besides the SM contribution, further affected by heavy new mediators that are much heavier than the EW scale, or amended by an additional decay channel with undetected light final states like dark matter or axion-like particles. These two scenarios can be most conveniently analyzed in the SMEFT and the dark SMEFT (DSMEFT) framework, respectively. We consider the flavour structures of the resulting effective operators to be either generic or satisfy the minimal flavour violation (MFV) hypothesis, both for the quark and lepton sectors. In the first scenario, once the MFV is assumed, only one SM-like low-energy effective operator induced by the SMEFT dim-6 operators can account for the Belle II excess, the parameter space of which is, however, excluded by the Belle upper bound on $\mathcal{B}(B^0\to K^{\ast 0}\nu \bar{\nu })$. In the second scenario, it is found that the Belle II excess can be accommodated by 22 of the DSMEFT operators involving one or two scalar, fermionic, or vector dark matters as well as ALPs. These operators also receive dominant constraints from the $B^0\to K^{\ast 0}+$inv and $B_s\to$inv decays. In the MFV hypothesis, the number of viable operators is reduced to 14, and the $B^{+}\to {\pi }^{+}+$inv and $K^{+}\to {\pi }^{+}+$inv decays start to put further constraints. Within the parameter space allowed by all the current experimental data, the $q^2$ distributions (and $F_L$) of the $B\to K^{(\ast )}+$inv decays are studied for each viable operator. In addition, we, for the first time, calculate systematically the longitudinal polarization fraction $F_L$ of $K^{\ast }$ in the $B\to K^{\ast }+$inv decays within the DLEFT.

    hep-phhep-exJHEP(2024)·59 citations
16. 16*

    FKS subtraction for quarkonium production at NLO

    Ajjath A H🇫🇷 · Hua-Sheng Shao🇫🇷 · Lukas Simon🇫🇷

    We extend the local infrared-divergence subtraction formalism, originally proposed by Frixione, Kunszt and Signer (FKS), to calculate short-distance (differential) cross section for any inclusive process involving a quarkonium particle in non-relativistic QCD (NRQCD) factorisation at next-to-leading order (NLO) accuracy in the strong coupling constant ${\alpha }_s$. The new formulas are generally applicable to the production of an S- or P-wave quarkonium state in association with any number of elementary particles. The main new ingredients derived in this paper are the local and integrated soft counterterms for the colour-singlet and colour-octet P-wave bound states. It, therefore, paves the way to the automation of the NLO calculations for heavy quarkonium inclusive and associated production processes.

    hep-phJHEP(2024)·9 citations
17. 17*

    Minimal SU(5) theory on the edge: the importance of being effective

    Goran Senjanović🇩🇪 · Michael Zantedeschi🇨🇳

    It is well known that the minimal renormalizable $SU(5)$ grand unified theory is ruled out: it predicts same masses of down quarks and charged leptons, the gauge couplings do not unify and neutrinos are massless. We show here that all this can be cured simultaneously by the addition of higher-dimensional effective operators. However, the theory lives on the edge since the unification scale turns out as low as roughly $10^{14}$GeV, threatening proton longevity. If the lower bound on the proton lifetime was to be increased by an order of magnitude, the usual desert in energies between the weak and unification scales would be populated. We also revisit two minimal extensions of this theory that offer a dynamical seesaw origin of neutrino mass, and discuss the resulting consequences.

    hep-phhep-thPRD(2024)·16 citations
18. 18*

    Revisiting $O(N)$ $\sigma$ model at unphysical pion masses and high temperatures

    Yuan-Lin Lyu🇨🇳 · Qu-Zhi Li🇨🇳 · Zhiguang Xiao🇨🇳 · Han-Qing Zheng🇨🇳

    Roy-equation analyses on lattice data of $\pi \pi$ scattering phase shifts at $m_{\pi }=391$MeV reveals that the lowest $f_0$ meson becomes a bound state under this condition. In addition, there is a pair of complex poles below threshold generated by crossing symmetry [X.-H. Cao et al., Phys. Rev. D 108, 034009 (2023)]. We use the $N/D$ method to partially recover crossing symmetry of the $O(N)$ $\sigma$ model amplitude at leading order of $1/N$ expansion, and qualitatively reproduce the pole structure and pole trajectories with varying pion masses as revealed by Roy-equation analyses. The $\sigma$ pole trajectory with varying temperature is also discussed and found to be similar to its properties when varying $m_{\pi }$. As the temperature increases, the complex $\sigma$ poles firstly move from the second Riemann sheet to the real axis becoming two virtual state poles, and then one virtual state pole moves to the first sheet turning into a bound state pole and finally tends to the pion pole position at high temperature which is as expected from the chiral symmetry restoration. Our results provide further evidences that the lowest $f_0$ state extracted from experiments and lattice data plays the role of $\sigma$ meson in the spontaneous breaking of chiral symmetry. Finally, we also briefly discuss the problems of the effective potential in the situation when $m_{\pi }$ and temperature get large.

    hep-phhep-lathep-thnucl-thPRD(2024)·7 citations
19. 19*

    New Physics with PeV Astrophysical Neutrino Beams

    Ibrahim Safa🇺🇸

    Astrophysical neutrinos allow us to access energies and baselines that cannot be reached by human-made accelerators, offering unique probes of new physics phenomena. This thesis aims to address the challenges currently facing searches for Beyond Standard Model (BSM) physics in the high-energy universe using astrophysical neutrinos, particularly in the contexts of flavor measurements and connections with dark matter.

    hep-phhep-ex0 citations
20. 20*

    Hard-scattering approach to strongly hindered electric dipole transitions between heavy quarkonia

    Cai-Ping Jia🇨🇳 · Yu Jia🇨🇳 · Junliang Lu🇨🇳 · Zhewen Mo🇨🇳 · Jia-Yue Zhang🇺🇸

    The conventional wisdom in dealing with electromagnetic transition between heavy quarkonia is the multipole expansion, when the emitted photon has a typical energy of order quarkonium binding energy. Nevertheless, in the case when the energy carried by the photon is of order typical heavy quark momentum, the multipole expansion doctrine is expected to break down. In this work, we apply the "hard-scattering" approach originally developed to tackle the strongly hindered magnetic dipole ($M1$) transition [Y.~Jia {\it et al.}, Phys. \ Rev. \ D. 82, 014008 (2010)] to the strongly hindered electric dipole ($E1$) transition between heavy quarkonia. We derive the factorization formula for the strongly hindered $E1$ transition rates at the lowest order in velocity and ${\alpha }_s$ in the context of the non-relativistic QCD (NRQCD), and conduct a detailed numerical comparison with the standard predictions for various bottomonia and charmonia $E1$ transition processes.

    hep-phhep-exPRD(2024)·0 citations
21. 21*

    Neutrino zeromodes on electroweak strings in light of topological insulators

    Minoru Eto🇯🇵 · Yu Hamada🇩🇪 · Ryusuke Jinno🇯🇵 · Muneto Nitta🇯🇵 · Masatoshi Yamada🇨🇳

    We examine neutrino zeromode solutions on the electroweak $Z$-string and their effect on the stability of the string in the standard model and its extensions. We propose using topological invariants constructed from the momentum (and real) space topology of Green's functions, often used for investigating edge modes in condensed matter physics. We analyze the standard model and then examine type-I and type-II extensions of the neutrino sector as well as their hybrid. Based on this analysis, we also comment on proposals in the literature to stabilize the $Z$-string.

    hep-phcond-mat.mes-hallhep-thJHEP(2024)·6 citations
22. 22*

    Investigation of full-charm and full-bottom pentaquark states

    K. Azizi🇮🇷 · Y. Sarac🇹🇷 · H. Sundu🇹🇷

    The continuous advancement of experimental techniques and investigations has led to observations of various exotic states in particle physics. Each addition to this family of states not only raises expectations for future discoveries but also focuses attention on such potential new states. Building upon this motivation and inspired by recent observations of various traditional and exotic particles containing an increased number of heavy quarks, our study provides a spectroscopic search for potential pentaquark states with spin-parity ${\frac{3}{2}}^{-}$ and composed entirely of charm or bottom quarks. We predict the masses for full-charm and full-bottom pentaquark states as $m=7628\pm 112$~MeV and $m=21982\pm 144$~MeV, respectively. We also compute the current couplings of these states to vacuum, which are main inputs in investigations of their various possible decays.

    hep-phhep-exhep-latEPJC(2024)·8 citations
23. 23*

    Observational Probes of the Neutron Star Equation of State with Hyperons, Bosonic Dark Matter, and Quark Matter

    Mahboubeh Shahrbaf🇵🇱 · Davood Rafiei Karkevandi🇮🇷 · Alexander Ayriyan🇵🇱 · Stefan Typel🇩🇪

    Context. The presence of dark matter in neutron stars is of growing interest due to its potential impact on the structure and observable properties of these objects. Among the various candidates, the hypothetical sexaquark has emerged as a promising bosonic dark matter particle, potentially forming under extreme conditions in neutron star cores. Aims. We investigate whether a hybrid neutron star model that includes hyperons, bosonic dark matter (in the form of sexaquarks), and deconfined quark matter can satisfy all current observational constraints. We particularly focus on identifying the range of sexaquark masses consistent with mass-radius measurements and the tidal deformability limit. Methods. We used the DD2Y-T model for the hadronic phase, which includes hyperons, and a nonlocal Nambu-Jona-Lasinio model for the deconfined quark phase. The phase transition was modeled as a smooth crossover using the replacement interpolation construction method. Sexaquark-baryon interactions were introduced via an effective mass shift representing repulsion. We incorporated the full set of current observational data, including NICER measurements of PSRs J0437-4715 and newly published J0614-3329 data, and performed a Bayesian analysis to constrain the sexaquark mass. Results. Our results show that the presence of the sexaquark softens the equation of state, enabling the hybrid model to satisfy both the radius and tidal deformability constraints around the canonical 1.4 M_\odot neutron stars. We find that hybrid EOSs with a sexaquark mass around 1900 MeV are in agreement with all available constraints, including those from HESS J1731-347 and PSR J0952-0607, which represent the lowest and highest mass neutron stars observed to date. The Bayesian analysis favors a sexaquark mass range of 1885-1935 MeV, supporting the potential relevance of this exotic particle in neutron star interiors.

    ↳ nucl-thhep-phAstron.Astrophys.(2026)·17 citations
24. 24*

    Relativistic fluctuations in stochastic fluid dynamics

    Xin An🇵🇱 · Gokce Basar🇺🇸 · Mikhail Stephanov🇺🇸 · Ho-Ung Yee🇺🇸

    The state-of-the-art theoretical formalism for a covariant description of non-Gaussian fluctuation dynamics in relativistic fluids is discussed.

    ↳ hep-thcond-mat.stat-mechhep-phnucl-thEPJ Web Conf.(2024)·1 citation
25. 25*

    A direct probe of $\Lambda$ potential in nuclear medium

    Gao-Chan Yong🇨🇳

    Using the Liège intranuclear-cascade model together with the ablation model ABLA, an investigation is conducted into the effects of $\Lambda$ potential in $\Lambda$-nucleus and $\Lambda$-hypernucleus-nucleus collisions across various beam energies. The findings show that the angle and transverse-momentum distributions of scattered $\Lambda$ hyperon, the scattering cross section of the $\Lambda$ hyperon in $\Lambda$-nucleus collisions as well as the rapidity distribution of $\Lambda$ hyperon in $\Lambda$-hypernucleus-nucleus collisions are significantly influenced by the strength of the $\Lambda$ potential in these scattering reactions across various beam energies. These demonstrations, unhindered by the uncertainties of $\Lambda$ and hypernuclei productions in nuclear medium, allow for a direct investigation of the $\Lambda$ potential, especially its momentum dependence. The criticality of probing the $\Lambda$ potential is closely associated with the resolution of the "hyperon puzzle" in neutron stars.

    ↳ nucl-thhep-exhep-phnucl-exPLB(2024)·4 citations
26. 26*

    Weak Lensing Constraints on Dark Matter-Baryon Interactions with $N$-Body Simulations and Machine Learning

    Chi Zhang🇨🇳 · Lei Zu🇨🇳 · Hou-Zun Chen🇨🇳 · Yue-Lin Sming Tsai🇨🇳 · Yi-Zhong Fan🇨🇳

    We investigate the elastic scattering cross section between dark matter and protons using the DES Year 3 weak lensing data. This scattering induces a dark acoustic oscillation structure in the matter power spectra. To address non-linear effects at low redshift, we utilize principal component analysis alongside a limited set of $N$-body simulations, improving the reliability of our matter power spectrum prediction. We further perform a robust Markov Chain Monte Carlo analysis to derive the upper bounds on the DM-proton elastic scattering cross-section, assuming different velocity dependencies. Our results, presented as the first Frequentist upper limits, are compared with the ones obtained by Bayesian approach. Compared with the upper limits derived from the Planck cosmic microwave background data, our findings from DES Year 3 data exhibit improvements of up to a factor of five. In addition, we forecast the future sensitivities of the China Space Station Telescope, the upcoming capabilities of this telescope could improve the current limits by approximately one order of magnitude.

    ↳ astro-ph.COastro-ph.HEhep-phJCAP(2024)·6 citations
27. 27*

    Hadron-quark phase transition in the neutron star with vector MIT bag model and Korea-IBS-Daegu-SKKU functional

    Debashree Sen🇰🇷 · Hana Gil🇰🇷 · Chang Ho Hyun🇰🇷

    Employing the Korea-IBS-Daegu-SKKU (KIDS) density functional for the hadron phase and the MIT bag model with vector (vBag) model for the quark phase, we obtain hadron-quark phase transition in neutron stars considering Maxwell construction. The structural properties of the resultant hybrid stars are computed for three different values of bag constant ($B$) in the range $B^{1/4}=$(145$-$160 MeV). We study the effects of symmetry energy ($J$) on the hybrid star properties with the different KIDS model and found that $J$ has important influence not only on the transition properties like the transition mass, transition radius and jump in density due to phase transition, but also on the stability of the hybrid stars. The vector repulsion of the quark phase via the parameter $G_V$ has profound influence in obtaining reasonable hybrid star configurations, consistent with the recent astrophysical constraints on the structural properties of compact stars. Within the aforesaid range of $B$, the value of $G_V$ is constrained to be 0.3 $\lesssim G_V\lesssim$ 0.4 in order to obtain reasonable hybrid star configurations.

    ↳ nucl-thhep-phFront.Astron.Space Sci.(2024)·6 citations
28. 28*

    Induced Gravitational Wave interpretation of PTA data: a complete study for general equation of state

    Guillem Domènech🇩🇪 · Shi Pi🇨🇳 · Ao Wang🇨🇳 · Jianing Wang🇨🇳

    We thoroughly study the induced gravitational wave interpretation of the possible gravitational wave background reported by PTA collaborations, considering the unknown equation of state $w$ of the early universe. We perform a Bayesian analysis of the NANOGrav data using the publicly available \textsc{PTArcade} code together with \textsc{SIGWfast} for the numerical integration of the induced gravitational wave spectrum. We focus on two cases: a monochromatic and a log-normal primordial spectrum of fluctuations. For the log-normal spectrum, we show that, while the results are not very sensitive to $w$ when the GW peak is close to the PTA window, radiation domination is out of the $2\sigma$ contours when only the infra-red power-law tail contributes. For the monochromatic spectrum, the $2\sigma$ bounds yield $0.1\lesssim w\lesssim 0.9$ so that radiation domination is close to the central value. We also investigate the primordial black hole (PBH) counterpart using the peak formalism. We show that, in general terms, a larger width and stiffer equation of state alleviates the overproduction of PBHs. No PBH overproduction requires $w\gtrsim 0.42$ up to 2-$\sigma$ level for the monochromatic spectrum. Furthermore, including bounds from the cosmic microwave background, we find in general that the mass range of the PBH counterpart is bounded by $10^{-5}{M}_{\odot }\lesssim M_{\mathrm{PBH}}\lesssim 10^{-1}{M}_{\odot }$. Lastly, we find that the PTA signal can explain the microlensing events reported by OGLE for $0.42\lesssim w\lesssim 0.50$. Our work showcases a complete treatment of induced gravitational waves and primordial black holes for general $w$ for future data analysis.

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2024)·71 citations
29. 29*

    Bosonic dark matter dynamics in hybrid neutron stars

    Zakary Buras-Stubbs🇵🇹 · Ilídio Lopes🇵🇹

    This research studies the intricate interplay between dark and baryonic matter within hybrid neutron stars enriched by anisotropic bosonic dark matter halos. Our modelling, guided by the equation of state with a free parameter, reveals diverse mass-radius correlations for these astronomical objects. A pivotal result is the influence of dark matter characteristics - whether condensed or dispersed - on the observable attributes of neutron stars based on their masses. Our investigation into anisotropic models, which offer a notably authentic representation of dark matter anisotropy, reveals a unique low-density core halo profile, distinguishing it from alternative approaches. Insights gleaned from galactic clusters have further refined our understanding of the bosonic dark matter paradigm. Observational constraints derived from the dynamics of galaxy clusters have been fundamental in defining the dark matter particle mass to lie between 0.05 GeV and 0.5 GeV and the scattering length to range from 0.9 fm to 3 fm. Using terrestrial Bose-Einstein condensate experiments, we have narrowed down the properties of bosonic dark matter, especially in the often overlooked 3 to 30 GeV mass range. Our findings fortify the understanding of dark and baryonic matter synergies in hybrid neutron stars, establishing a robust foundation for future astrophysical pursuits.

    ↳ astro-ph.HEastro-ph.COhep-phPRD(2024)·28 citations
30. 30*

    Bogoliubov phonons in a Bose-Einstein condensate from the one-loop perturbative renormalization group

    Niklas Rasch · Aleksandr N. Mikheev🇩🇪 · Thomas Gasenzer🇩🇪

    Wilson's renormalization-group approach to the weakly-interacting single-component Bose gas is discussed within the symmetry-broken, condensate phase. Extending upon the work by Bijlsma and Stoof [Phys. Rev. A 54, 5085 (1996), see http://doi.org/10.1103/PhysRevA.54.5085 ], wave-function renormalization of the temporal derivative contributions to the effective action is included in order to capture sound-like quasiparticle excitations with wave lengths larger than the healing-length scale. By means of a suitable rescaling scheme we achieve convergence of the coupling flows, which serve as a means to determine the condensate depletion in accordance with Bogoliubov theory, as well as the interaction-induced shift of the critical temperature.

    ↳ cond-mat.quant-gashep-phSciPost Phys.Core(2024)·0 citations
31. 31*

    Fast neutrino flavor conversions in a supernova: Emergence, evolution, and effects

    Zewei Xiong🇩🇪 · Meng-Ru Wu🇹🇼 · Manu George🇹🇼 · Chun-Yu Lin🇹🇼 · Noshad Khosravi Largani🇵🇱 · Tobias Fischer🇵🇱 · Gabriel Martínez-Pinedo🇩🇪

    Fast flavor conversions (FFCs) of neutrinos, which can occur in core-collapse supernovae (CCSNe), are multiangle effects. They depend on the angular distribution of the neutrino's electron lepton number (ELN). In this work, we present a comprehensive study of the FFCs by solving the multienergy and multiangle quantum kinetic equations with an extended set of collisional weak processes based on a static and spherically symmetric CCSN matter background profile. We investigate the emergence and evolution of FFCs in models featuring different ELN angular distributions, considering scenarios with two and three neutrino flavors. The spectrogram method is utilized to illustrate the small-scale spatial structure, and we show that this structure of neutrino flavor coherence and number densities in the nonlinear regime is qualitatively consistent with the dispersion relation analysis. On the coarse-grained level, we find that different asymptotic states can be achieved following the FFCs depending on the locations and shapes of the ELN distributions, despite sharing a common feature of the elimination of the ELN angular crossing. While equilibration among different neutrino flavors may be achieved immediately after the prompt FFCs, it is not a general outcome of the asymptotic state, as subsequent feedback effects from collisional neutrino-matter interactions come into play, particularly for cases where FFCs occur inside the neutrinosphere. The impacts of FFCs and the feedback effect on the net neutrino heating rates, the equilibrium electron fraction of CCSN matter, and the free-streaming neutrino energy spectra are quantitatively assessed. Other aspects including the impact of the vacuum term and the coexistence with other type of flavor instabilities are also discussed.

    ↳ astro-ph.HEhep-phPRD(2024)·49 citations
32. 32*

    Viscoelastic response and anisotropic hydrodynamics in Weyl semimetals

    A. A. Herasymchuk · E. V. Gorbar🇺🇦 · P. O. Sukhachov

    We study viscoelastic response in Weyl semimetals with broken time-reversal symmetry. The principal finding is that topology and anisotropy of the Fermi surface are manifested in the viscoelasticity tensor of the electron fluid. In the dynamic (interband) part of this tensor, the anisotropy leads to a qualitatively different, compared with isotropic models, scaling with frequency and the Fermi energy. The components of the viscosity tensor determined by the Fermi-surface properties agree in the Kubo and kinetic formalisms; the latter, however, misses the anomalous Hall viscosity originating from filled states below the Fermi surface. The anisotropy of the dispersion relation is also manifested in the acceleration and relaxation terms of the hydrodynamic equations providing means to probe the anisotropy in transport experiments.

    ↳ cond-mat.mes-hallcond-mat.str-elhep-phPRB(2024)·0 citations
33. 33*

    Infinite Order Hydrodynamics: An Analytical Example

    Lorenzo Gavassino🇺🇸

    We construct a kinetic model for matter-radiation interactions whose hydrodynamic gradient expansion can be computed analytically up to infinite order in derivatives, in the fully nonlinear regime, and for arbitrary flows. The frequency dependence of the opacity of matter is chosen to mimic the relaxation time of a self-interacting scalar field. In this way, the transient sector simulates that of a realistic quantum field theory. The gradient series is found to diverge for most flows, in agreement with previous findings. We identify, for the model at hand, the mechanism at the origin of the divergence, and we provide a successful regularization scheme. Additionally, we propose a universal qualitative framework for predicting the breakdown of the gradient expansion of an arbitrary microscopic system undergoing a given flow. This framework correctly recovers all previously known instances of gradient expansion divergence. As a new prediction, we show that the gradient expansion diverges when the energy-dependent mean free path is unbounded above.

    ↳ nucl-thastro-ph.HEgr-qchep-ph+1PRL(2024)·12 citations
34. 34*

    Trans-series from condensates

    Marcos Marino🇨🇭 · Ramon Miravitllas🇨🇭

    The Shifman-Vainshtein-Zakharov (SVZ) sum rules provide a method to obtain trans-series expansions in many quantum field theories, in which exponentially small corrections are calculated by combining the operator product expansion with the assumption of vacuum condensates. In some solvable models, exact expressions for trans-series can be obtained from non-perturbative results, and this makes it possible to test the SVZ method by comparing its predictions to these exact trans-series. In this paper we perform such a precision test in the example of the fermion self-energy in the Gross-Neveu model. Its exact trans-series expansion can be extracted from the large $N$ solution, at the first non-trivial order in $1/N$. It is given by an infinite series of exponentially small corrections involving factorially divergent power series in the 't Hooft parameter. We show that the first two corrections are associated to two-quark and four-quark condensates, and we reproduce the corresponding power series exactly, and at all loops, by using the SVZ method. In addition, the numerical values of the condensates can be extracted from the exact result, up to order $1/N$.

    ↳ hep-thhep-phSciPost Phys.(2025)·19 citations
35. 35*

    Testing gravitational waveforms in full General Relativity

    Fabio D'Ambrosio🇨🇭 · Francesco Gozzini🇩🇪 · Lavinia Heisenberg🇩🇪 · Henri Inchauspé🇩🇪 · David Maibach🇩🇪 · Jann Zosso🇨🇭

    We perform a comprehensive analysis of state-of-the-art waveform models, focusing on their predictions concerning kick velocity and inferred gravitational wave memory. In our investigation we assess the accuracy of waveform models using energy-momentum balance laws, which were derived in the framework of full, non-linear General Relativity. The numerical accuracy assessment is performed for precessing as well as non-precessing scenarios for models belonging to the \textit{EOB}, \textit{Phenom}, and \textit{Surrogate} families. We analyze the deviations of these models from each other and from Numerical Relativity waveforms. Our analysis reveals statistically significant deviations, which we trace back to inaccuracies in modelling subdominant modes and inherent systematic errors in the chosen models. We corroborate our findings through analytical considerations regarding the mixing of harmonic modes in the computed kick velocities and inferred memories.

    ↳ gr-qcastro-ph.COhep-phhep-thJCAP(2025)·8 citations
36. 36*

    Cutting-Edge Tools for Cutting Edges

    Ruth Britto🇮🇪 · Claude Duhr🇩🇪 · Holmfridur S. Hannesdottir🇺🇸 · Sebastian Mizera🇺🇸

    We review different notions of cuts appearing throughout the literature on scattering amplitudes. Despite similar names, such as unitarity cuts or generalized cuts, they often represent distinct computations and distinct physics. We consolidate this knowledge, summarize how cuts are used in various computational strategies, and explain their relations to other quantities including imaginary parts, discontinuities, and monodromies. Differences and nuances are illustrated on explicit examples.

    ↳ hep-thhep-ph34 citations
37. 37*

    A Model for Pair Production Limit Cycles in Pulsar Magnetospheres

    Takuya Okawa🇺🇸 · Alexander Y. Chen🇹🇼

    It was recently proposed that the electric field oscillation as a result of self-consistent $e^{\pm }$ pair production may be the source of coherent radio emission from pulsars. Direct Particle-in-Cell (PIC) simulations of this process have shown that the screening of the parallel electric field by this pair cascade manifests as a limit cycle, as the parallel electric field is recurrently induced when pairs produced in the cascade escape from the gap region. In this work, we develop a simplified time-dependent kinetic model of $e^{\pm }$ pair cascades in pulsar magnetospheres that can reproduce the limit-cycle behavior of pair production and electric field screening. This model includes the effects of a magnetospheric current, the escape of $e^{\pm }$, as well as the dynamic dependence of pair production rate on the plasma density and energy. Using this simple theoretical model, we show that the power spectrum of electric field oscillations averaged over many limit cycles is compatible with the observed pulsar radio spectrum.

    ↳ astro-ph.HEhep-phApJ(2024)·5 citations
38. 38*

    Sudden breakdown of effective field theory near cool Kerr-Newman black holes

    Gary T. Horowitz🇺🇸 · Maciej Kolanowski🇺🇸 · Grant N. Remmen🇺🇸 · Jorge E. Santos🇬🇧

    It was recently shown that (near-)extremal Kerr black holes are sensitive probes of small higher-derivative corrections to general relativity. In particular, these corrections produce diverging tidal forces on the horizon in the extremal limit. We show that adding a black hole charge makes this effect qualitatively stronger. Higher-derivative corrections to the Kerr-Newman solution produce tidal forces that scale inversely in the black hole temperature. We find that, unlike the Kerr case, for realistic values of the black hole charge large tidal forces can arise before quantum corrections due to the Schwarzian mode become important, so that the near-horizon behavior of the black hole is dictated by higher-derivative terms in the effective theory.

    ↳ hep-thastro-ph.HEgr-qchep-phJHEP(2024)·43 citations
39. 39*

    Late-Time constraints on Interacting Dark Energy: Analysis independent of $H_0$, $r_d$ and $M_B$

    David Benisty🇩🇪 · Supriya Pan🇮🇳 · Denitsa Staicova🇧🇬 · Eleonora Di Valentino🇬🇧 · Rafael C. Nunes🇧🇷

    We investigated a possible interaction between cold dark matter and dark energy, corresponding to a well-known interacting dark energy model discussed in the literature within the context of resolving the Hubble tension. We put constraints on it in a novel way, by creating new likelihoods with an analytical marginalization over the Hubble parameter $H_0$, the sound horizon $r_d$, and the supernova absolute magnitude $M_B$. Our aim is to investigate the impacts on the coupling parameter of the interacting model, $\xi$, and the equation of state of dark energy $w$ and the matter density parameter ${\Omega }_{m,0}$. The late-time cosmological probes used in our analysis include the PantheonPlus (calibrated and uncalibrated), cosmic chronometers, and baryon acoustic oscillation samples and the Pantheon for comparison. Through various combinations of these datasets, we demonstrate hints of an up to $2\sigma$ deviation from the standard $\Lambda$ cold dark matter model.

    ↳ astro-ph.COgr-qchep-phhep-thAstron.Astrophys.(2024)·75 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.