Tue·Apr 25, 2023Tuesday·April 25, 2023

1. 01*

   Measuring axion gradients with photon interferometry (MAGPI)

   Michael A. Fedderke🇺🇸 · Jedidiah O. Thompson🇺🇸 · Raphael Cervantes🇺🇸 · Bianca Giaccone🇺🇸 · Roni Harnik🇺🇸 · David E. Kaplan🇺🇸 · Sam Posen🇺🇸 · Surjeet Rajendran🇺🇸

   We propose a novel search technique for axions with a $CP$-violating monopole coupling ${\tilde{g}}_Q$ to bulk Standard Model charges $Q\in \{B,L,B-L\}$. Gradients in the static axion field configurations sourced by matter induce achromatic circular photon birefringence via the axion-photon coupling $g_{\varphi \gamma }$. Circularly polarized light fed into an optical or (open) radio-frequency (RF) Fabry-Pérot (FP) cavity develops a phase shift that accumulates up to the cavity finesse: the fixed axion spatial gradient prevents a cancellation known to occur for an axion dark-matter search. The relative phase shift between two FP cavities fed with opposite circular polarizations can be detected interferometrically. This time-independent signal can be modulated up to non-zero frequency by altering the cavity orientations with respect to the field gradient. Multi-wavelength co-metrology techniques can be used to address chromatic measurement systematics and noise sources. With Earth as the axion source, we project reach beyond current constraints on the product of couplings ${\tilde{g}}_Q{g}_{\varphi \gamma }$ for axion masses $m_{\varphi }\lesssim 10^{-5}\mathrm{eV}$. If shot-noise-limited sensitivity can be achieved, an experiment using high-finesse RF FP cavities could reach a factor of $\sim 10^5$ into new parameter space for ${\tilde{g}}_Q{g}_{\varphi \gamma }$ for masses $m_{\varphi }\lesssim 4\times 10^{-11}\mathrm{eV}$.

   hep-phphysics.ins-detphysics.opticsPRD(2024)·11 citations
2. 02*

   Scalar extensions of the SM and recent experimental anomalies

   Thomas Biekötter🇩🇪

   The Brout-Englert-Higgs mechanism describes the generation of masses of fundamental particles in the Standard Model (SM). It predicts the existence of one scalar particle with precisely predicted couplings to fermions and gauge bosons. Deviations from these predictions, such as the observation of additional scalar particles, would indicate non-minimal Higgs sectors and beyond-the-SM physics. We motivate extended scalar sectors based on theoretical and observational grounds and discuss their possible manifestations at colliders or gravitational-wave experiments. We explore smoking-gun signatures of electroweak baryogenesis at the LHC or a future $e^{+}{e}^{-}$ collider, and we examine their interplay with the observation of a primordial gravitational-wave background at LISA. We also consider the possibility of an additional Higgs boson at about 95 GeV motivated by excesses in diphoton and ditau final states observed by CMS. Finally, we discuss the impact of the CDF measurement of the $W$-boson mass on the parameter space of scalar extensions of the SM.

   hep-ph5 citations
3. 03*

   Initial state radiation in $e^{+}{e}^{-}$ annihilation

   Göran Fäldt🇸🇪

   In two earlier papers it was demonstrated that Lorentzian and Galilean symmetries could both be useful in the analysis of the annihilation reaction $e^{+}{e}^{-}\to \gamma \Lambda (\to p{\pi }^{-})\bar{\Lambda }(\to \bar{p}{\pi }^{+})$. It was also demonstrated that any pair of hyperon form factors would be acceptable, but that the $\{G_E,G_M\}$ pair would probably be the simplest one to handle.

   hep-ph0 citations
4. 04*

   Polarized $Z$ cross sections in Higgsstrahlung for the determination of anomalous $ZZH$ couplings

   Kumar Rao🇮🇳 · Saurabh D. Rindani🇮🇳 · Priyanka Sarmah🇮🇳 · Balbeer Singh🇮🇳

   The production of a Higgs boson in association with a $Z$ at an electron-positron collider is one of the cleanest methods for the measurement of the couplings of the Higgs boson. In view of the large production cross section at energies a little above the threshold, it seems feasible to make a more detailed study of the process by measuring the cross sections for polarized $Z$ in order to measure possible anomalous $ZZH$ couplings. We show that certain combinations of cross sections in $e^{+}{e}^{-}\to ZH$ with different $Z$ polarizations help to enhance or isolate the effect of one of the two kinds of anomalous $ZZH$ couplings possible on general grounds of CP and Lorentz invariance. These combinations can be useful to get information on the $ZZH$ coupling in the specific contexts of an effective field theory, two-Higgs-doublet models, and composite Higgs models, in a relatively model-independent fashion. We find in particular that the longitudinal helicity fraction of the $Z$ is expected to be insensitive to anomalous couplings, and would be close to its value in the standard model in the scenarios we consider. We also discuss the sensitivity of the proposed measurements to the anomalous couplings, including longitudinal beam polarizations, which suppress backgrounds, and can improve the sensitivity if appropriately chosen.

   hep-phPLB(2023)·3 citations
5. 05*

   QCD one-loop correction to Higgs boson decay into quarkonium-pair

   I. N. Belov🇮🇹 · A. V. Berezhnoy🇷🇺 · E. A. Leshchenko🇷🇺 · A.K. Likhoded🇷🇺

   Rare decays of the Higgs boson into quarkonia-pairs are studied within the framework of NRQCD approach. The main decay mechanisms and their interference are studied in detail. One-loop corrections to the widths of these decays are taken into account for the first time.

   hep-phPRD(2023)·4 citations
6. 06*

   The LBK theorem to all orders

   Tim Engel🇩🇪

   We study the soft limit of one-photon radiation at next-to-leading power (NLP) in the framework of heavy-quark effective theory (HQET) to all orders in perturbation theory. We establish the soft theorem that for unpolarised scattering the radiative contribution up to NLP is entirely determined by the non-radiative amplitude. This generalises the Low-Burnett-Kroll (LBK) theorem for QED to all orders. All hard matching corrections can be calculated by applying the LBK differential operator to the non-radiative amplitude. The virtual corrections in the effective theory vanish beyond one loop, resulting in a one-loop exact soft function. As a first, non-trivial application we calculate the real-virtual-virtual electron-line corrections to muon-electron scattering at NLP in the soft limit.

   hep-phhep-thJHEP(2023)·28 citations
7. 07*

   Gauge choice for organizing infrared singularities in QCD

   Zoltan Nagy🇩🇪 · Davison E. Soper🇺🇸

   We explore the features of interpolating gauge for QCD. This gauge, defined by Doust and by Baulieu and Zwanziger, interpolates between Feynman gauge or Lorenz gauge and Coulomb gauge. We argue that it could be useful for defining the splitting functions for a parton shower beyond order $\text{as}$ or for defining the infrared subtraction terms for higher order perturbative calculations.

   hep-phhep-thPRD(2023)·1 citation
8. 08*

   Quantum Science and the Search for Axion Dark Matter

   Alexander O. Sushkov🇺🇸

   The dark matter puzzle is one of the most important open problems in modern physics. The ultra-light axion is a well-motivated dark matter candidate, conceived to resolve the strong-CP problem of quantum chromodynamics. Numerous precision experiments are searching for the three non-gravitational interactions of axion-like dark matter. Some of the searches are approaching fundamental quantum limits on their sensitivity. This Perspective describes several approaches that use quantum engineering to circumvent these limits. Squeezing and single-photon counting can enhance searches for the axion-photon interaction. Optimization of quantum spin ensemble properties is needed to realize the full potential of spin-based searches for the electric-dipole-moment and the gradient interactions of axion dark matter. Several metrological and sensing techniques, developed in the field of quantum information science, are finding natural applications in this area of experimental fundamental physics.

   hep-phquant-phPRX Quantum(2023)·35 citations
9. 09*

   Imprint of PBH domination on gravitational waves generated by cosmic strings

   Debasish Borah🇮🇳 · Suruj Jyoti Das🇮🇳 · Rishav Roshan🇰🇷 · Rome Samanta🇨🇿

   We study the effect of an ultra-light primordial black hole (PBH) dominated phase on the gravitational wave (GW) spectrum generated by a cosmic string (CS) network formed as a result of a high-scale $U(1)$ symmetry breaking. A PBH-dominated phase leads to tilts in the spectrum via entropy dilution and generates a new GW spectrum from PBH density fluctuations, detectable at ongoing and planned near-future GW detectors. The combined spectrum has a unique shape with a plateau, a sharp tilted peak over the plateau, and a characteristic fall-off, which can be distinguished from the one generated in the combination of CS and any other matter domination or new exotic physics. We discuss how ongoing and planned future experiments can probe such a unique spectrum for different values of $U(1)$ breaking scale and PBH parameters such as initial mass and energy fraction.

   hep-phastro-ph.COPRD(2023)·19 citations
10. 10*

    Charmless Semileptonic Baryonic $B_{u,d,s}$ Decays

    Chun-Khiang Chua🇹🇼

    We study ${\bar{B}}_q\to {\mathbf{B}\bar{\mathbf{B}}}^{\prime }l\bar{\nu }$ and ${\bar{B}}_q\to {\mathbf{B}\bar{\mathbf{B}}}^{\prime }\nu \bar{\nu }$ decays with all low lying octet and decuplet baryons using a topological amplitude approach. In tree induced ${\bar{B}}_q\to {\mathbf{B}\bar{\mathbf{B}}}^{\prime }l\bar{\nu }$ decay modes, we need 2 tree and 1 annihilation amplitudes in octet-anti-octet decay modes, 1 tree amplitude in octet-anti-decuplet decay modes, 1 tree amplitude in decuplet-anti-octet decay modes and 1 tree and 1 annihilation amplitudes in decuplet-anti-decuplet decay modes. In loop induced ${\bar{B}}_q\to {\mathbf{B}\bar{\mathbf{B}}}^{\prime }\nu \bar{\nu }$ decay modes, similar numbers of penguin-box and penguin-box-annihilation amplitudes are needed. Relations on these semileptonic baryonic $B_q$ decay amplitudes are found. Furthermore, the ratios of loop topological amplitudes and tree topological amplitudes are fixed by known CKM factors and loop functions. The observed $B^{-}\to p\bar{p}{\mu }^{-}\bar{\nu }$ differential rate exhibits threshold enhancement, which is expected to hold in all other semileptonic baryonic modes. The threshold enhancement squeezes the phase space and leads to very large SU(3) breaking effects in the decay rates. They are estimated using the measured $B^{-}\to p\bar{p}{\mu }^{-}\bar{\nu }$ differential rate and model calculations. Modes with relatively unsuppressed rates and good detectability are identified. These modes can be searched experimentally in near future and the rate estimations can be improved when more modes are discovered. Ratios of rates of some loop induced ${\bar{B}}_q\to {\mathbf{B}\bar{\mathbf{B}}}^{\prime }\nu \bar{\nu }$ decays and tree induced ${\bar{B}}_q\to {\mathbf{B}\bar{\mathbf{B}}}^{\prime }l\bar{\nu }$ decays are predicted and can be checked experimentally. They can be tests of the SM. Some implications on ${\bar{B}}_q\to {\mathbf{B}\bar{\mathbf{B}}}^{\prime }{l}^{+}{l}^{-}$ decays are also given.

    hep-phhep-exPRD(2023)·1 citation
11. 11*

    The Hierarchy Problem and the Top Yukawa

    Andreas Bally🇩🇪 · Yi Chung🇩🇪 · Florian Goertz🇩🇪

    In this talk, an alternative to top partner solutions and its consequences on phenomenology are discussed. The hierarchy problem from the top loop contribution is solved by mitigating the top Yukawa coupling at high scales. In this scenario, the new degrees of freedom appearing at the cut-off scale of the top loop should then be some new top-philic particles instead of traditional top partners. The idea can be directly tested through measurements in top physics, including $t\bar{t}h$, $t\bar{t}$ differential cross section, and $t\bar{t}t\bar{t}$ cross section.

    hep-ph6 citations
12. 12*

    QCD bound states in motion

    Paul Hoyer🇫🇮

    I consider the frame dependence of QCD bound states in the presence of a confining, spatially constant gluon field energy density. The states are quantized at equal time in $A^0=0$ (temporal) gauge. I derive the frame dependence of the wave functions, and demonstrate the Lorentz covariance of the electromagnetic (transition) form factors for states of any spin. The wave functions of $J^{PC}=0^{-+}$ states with CM momentum $P\ne 0$ are considered in some detail, verifying their local normalizability and the expected frame dependence of the bound state energy.

    hep-phnucl-thPRD(2023)·2 citations
13. 13*

    Investigating the impact of extra resonance states in the van der Waals Hadron Resonance Gas Model

    Nachiketa Sarkar🇮🇳

    We investigate, in addition to the experimentally established hadrons, how the inclusion of extra resonance states, through the Hagedorn mass spectrum (HS) or Quark Model (QM) predicated states, affects the thermodynamic and transport quantities of the hadronic system in the van der Waals hadron resonance gas (VDWHRG) model. We found that the VDWHRG model with the HS provides the most accurate description of the lattice QCD results, both at zero and finite chemical potential. Moreover, the inclusion of these extra states has a significant impact on the van der Waals (VDW) parameters, which, in turn, affect the thermodynamic and transport quantities as well as the likely position of the liquid-gas phase transition critical point in the QCD phase diagram. Additionally, we infer that there is a strong correlation between the van der Waals parameters and the chemical potential. Overall, our study sheds light on the importance of considering extra resonance states and proper tuning of the VDW parameters in the VDWHRG model to enhance the accuracy and reliability of the model in the context of Ultra-relativistic heavy-ion physics.

    hep-phnucl-th3 citations
14. 14*

    Electroweak superpartner production at 13.6 TeV with Resummino

    J. Fiaschi🇬🇧 · B. Fuks🇫🇷 · M. Klasen🇩🇪 · A. Neuwirth🇩🇪

    Due to the greater experimental precision expected from the currently ongoing LHC Run 3, equally accurate theoretical predictions are essential. We update the documentation of the Resummino package, a program dedicated to precision cross section calculations for the production of a pair of sleptons, electroweakinos, and leptons in the presence of extra gauge bosons, and for the production of an associated electroweakino-squark or electroweakino-gluino pair. We detail different additions that have been released since the initial version of the program a decade ago, and then use the code to investigate the impact of threshold resummation corrections at the next-to-next-to-leading-logarithmic accuracy. As an illustration of the code we consider the production of pairs of electroweakinos and sleptons at the LHC for centre-of-mass energies ranging up to 13.6 TeV and in simplified model scenarios. We find slightly increased total cross section values, accompanied by a significant decrease of the associated theoretical uncertainties. Furthermore, we explore the dependence of the results on the squark masses.

    hep-phEPJC(2023)·29 citations
15. 15*

    Diquark and chiral condensate in a self-consistent NJL-type model

    Wen-Li Yuan🇨🇳 · Jingyi Chao🇨🇳 · Ang Li🇨🇳

    In this work, a modified two-flavor NJL-type model is utilized, in which the contact current-current interaction is Fierz-transformed into quark-antiquark interactions and quark-quark interactions, which are directly related to the chiral condensate and diquark condensate, respectively. Under mean-field approximation, the chiral condensate and the diquark condensate are studied on the same footing. We discuss in detail the competition between the chiral condensate and the diquark condensate, which are exclusively paired with u and d quarks, while also investigating the order of the chiral phase transition through an analysis of the resulting chiral susceptibility.

    hep-phnucl-thPRD(2023)·14 citations
16. 16*

    Two-body hadronic decays of Xi^{0}_c in light front approach

    Hang Liu🇨🇳 · Chang Yang🇨🇳

    In this study, we investigate the nonleptonic decays of the charmed-baryon Xi^ {0} _ c induced by the c -> u(d\bar{d})/(s\bar{s}) transition. Utilizing the factorization assumption, we decompose the decay amplitudes in terms of transition form factors which are then calculated within the light-front quark model. We employ helicity amplitudes to analyze the nonleptonic decay modes of the charmed-baryon Xi^ {0} _c and derive benchmark results for decay widths and branching fractions. Our calculations suggest that the branching fractions for some of these rare nonleptonic decays are at the order of 10^ {-4} - 10^ {-3}, which are likely to be detectable at experiments such as LHCb or BESIII. The potential data accumulated in the future may help to further our understanding of the decay mechanism in the presence of charm quarks.

    hep-phPRD(2023)·3 citations
17. 17*

    Renormalization of Very Special Relativity gauge theories

    Jorge Alfaro🇨🇱

    Mandelstam-Leibbrandt(ML) regularization of Very Special Relativity (VSR) amplitudes in momentum space depends on two fixed null vectors $n_{\mu },{\bar{n}}_{\mu }$ besides external momenta. ML is known to preserve gauge invariance and naive power counting. The second null vector ${\bar{n}}_{\mu }$ destroys the $Sim(2)$ symmetry of the VSR model. We devise a systematic procedure to take the ${\bar{n}}_{\mu }->0$ limit to recover the lost $Sim(2)$ symmetry. The procedure produces $Sim(2)$ and gauge invariant loop amplitudes. We show how to use this method to remove unphysical terms from the Non Relativistic Potential of Very Special Relativity Quantum Electrodynamics(VSR QED) with a massive photon. Then we compute the one loop renormalization of VSR QED. Finally we derive the anomalous magnetic moment of the electron, modified by neutrino and photon mass; and comments on the phenomenological implications.

    hep-phhep-thJHEP(2023)·8 citations
18. 18*

    Improving the Composition of Ultra High Energy Cosmic Rays with Ground Detector Data

    Blaž Bortolato🇸🇮 · Jernej F. Kamenik🇸🇮 · Michele Tammaro🇸🇮

    We show that the maximum shower depth distributions of Ultra-High Energy Cosmic Rays (UHECRs), as measured by fluorescence telescopes, can be augmented by building a mapping to observables collected by surface detectors. The resulting statistical improvement of such augmented dataset depends in a universal way on the strength of the correlation exhibited by the mapping. Building upon the publicly available data on "golden hybrid" events from the Pierre Auger Observatory we project possible improvements in the inferred composition of UHECRs for a range of possible mappings with varying correlation strengths.

    ↳ astro-ph.HEhep-phPRD(2024)·2 citations
19. 19*

    Shimmering gravitons in the gamma-ray sky

    Sabir Ramazanov🇨🇿 · Rome Samanta🇨🇿 · Georg Trenkler🇨🇿 · Federico R. Urban🇨🇿

    What is the highest energy at which gravitons can be observed? We address this question by studying graviton-to-photon conversion - the inverse-Gertsenshtein effect - in the magnetic field of the Milky Way. We find that above $\sim 1\text{mbox}PeV$ the effective photon mass grows large enough to quench the conversion rate. For sub-PeV energies, the induced photon flux is comparable to the sensitivity of LHAASO to a diffuse $\gamma$-ray background, but only for graviton abundances of order ${\Omega }_{\text{gw}}{h}_0^2\sim 1$. In the future, owing to a better understanding of $\gamma$-ray backgrounds, larger effective areas and longer observation times, sub-PeV shimmering gravitons with a realistic abundance of ${\Omega }_{\text{gw}}{h}_0^2\sim 0.01$ could be detected. We show how such a large abundance is achieved in a cosmologically-motivated scenario of post-recombination superheavy dark matter decay. Therefore, the sub-PeV range might be the ultimate energy frontier at which gravitons can be observed.

    ↳ astro-ph.HEastro-ph.COhep-phhep-thJCAP(2023)·27 citations
20. 20*

    Initial Vorticities of Quark-Gluon Matter in Heavy-ion Collisions

    An-Ke Lei🇨🇳 · Du-Juan Wang🇨🇳 · Dai-Mei Zhou🇨🇳 · Ben-Hao Sa🇨🇳 · Laszlo Pal Csernai🇳🇴 · Larissa V. Bravina🇳🇴

    We calculate four types of initial vorticities in Au+Au collisions at energies $\sqrt{S_{NN}}$ = 5--200 GeV using a microscopic transport model PACIAE. Our simulation shows the non-monotonic dependence of the initial vorticities on the collision energies. The energy turning point is around 10-15 GeV for different vorticities but not sensitive to impact parameter.

    ↳ nucl-thhep-phhep-thIJMPE(2023)·0 citations
21. 21*

    Multi-messenger signals of heavy axionlike particles in core-collapse supernovae: two-dimensional simulations

    Kanji Mori🇯🇵 · Tomoya Takiwaki🇯🇵 · Kei Kotake🇯🇵 · Shunsaku Horiuchi🇺🇸

    Core-collapse supernovae are a useful laboratory to probe the nature of exotic particles. If axionlike particles (ALPs) are produced in supernovae, they can affect the transfer of energy and leave traces in observational signatures. In this work, we present results from two-dimensional supernova models including the effects of the production and the absorption of ALPs that couple with photons. It is found that the additional heating induced by ALPs can enhance the diagnostic energy of explosion, E_diag. For example, for moderate ALP-photon coupling, we find explosion energies ~0.6*10^51 erg compared to our reference model without ALPs of ~0.4*10^51 erg in the first ~0.5 s postbounce explored in this work. Our findings indicate that when the coupling constant is sufficiently high, the neutrino luminosities and mean energies are decreased because of the additional cooling of the proto-neutron star via ALPs. The gravitational wave amplitude is also reduced because the mass accretion on the proto-neutron star is suppressed. Although the ALP-photon coupling can foster explodability, including enhancing the explosion energy closer to recent observations, more long-term simulations in spatially three-dimension are needed to draw robust conclusions

    ↳ astro-ph.HEhep-phPRD(2023)·19 citations
22. 22*

    Dark Universe Phenomenology from Yukawa Potential?

    Kimet Jusufi (State U., Tetova)🇲🇰 · Genly Leon (Catolica del Norte U. and DUT, Durban)🇿🇦 · Alfredo D. Millano (Catolica del Norte U.)🇿🇦

    We argue that the effect of cold dark matter in the cosmological setup can be explained by the coupling between the baryonic matter particles in terms of the long-range force having a graviton mass $m_g$ via the Yukawa gravitational potential. Such a quantum-corrected Yukawa-like gravitational potential is characterized by the coupling parameter $\alpha$, the wavelength parameter $\lambda$, which is related to the graviton mass via $m_g=\hslash /(\lambda c)$, that determines the range of the force and, finally, a Planck length quantity $l_0$ that makes the potential regular at the centre. The corrected Friedmann equations are obtained using Verlinde's entropic force interpretation of gravity based on the holographic scenario and the equipartition law of energy. The parameter $\alpha$ modifies Newton's constant as $G_{\mathrm{eff}}\to G(1+\alpha )$. We argue that dark matter is an apparent effect as no dark matter particle exists in this picture. Furthermore, the dark energy is also related to graviton mass and $\alpha$; in particular, we point out that the cosmological constant can be viewed as a self-interaction effect between gravitons. We further show that there exists a precise correspondence with Verlinde's emergent gravity theory, and due to the long-range force, the theory can be viewed as a non-local gravity theory. To this end, we performed the phase space analyses and estimated $\lambda \simeq 10^3$[Mpc] and $\alpha \in (0.0385,0.0450)$, respectively. Finally, from these values, for the graviton mass, we get $m_g\simeq 10^{-68}$ kg, and cosmological constant $\Lambda \simeq 10^{-52}{\mathrm{m}}^{-2}$. Further, we argue how this theory reproduces the MOND phenomenology on galactic scales via the acceleration of Milgrom $a_0\simeq 10^{-10}m/{\mathrm{s}}^2$.

    ↳ gr-qchep-phhep-thPhys.Dark Univ.(2023)·30 citations
23. 23*

    Infrared fixed point and anomalous dimensions in a composite Higgs model

    Anna Hasenfratz🇺🇸 · Ethan T. Neil🇺🇸 · Yigal Shamir🇮🇱 · Benjamin Svetitsky🇮🇱 · Oliver Witzel🇩🇪

    We use lattice simulations and the continuous renormalization-group method, based on the gradient flow, to study a candidate theory of composite Higgs and a partially composite top. The model is an SU(4) gauge theory with four Dirac fermions in each of the fundamental and two-index antisymmetric representations. We find that the theory has an infrared fixed point at $g^2\simeq 15.5$ in the gradient flow scheme. The mass anomalous dimension of each representation is large at the fixed point. On the other hand, the anomalous dimensions of top-partner operators do not exceed 0.5 at the fixed point. This may not be large enough for a phenomenologically successful model of partial compositeness.

    ↳ hep-lathep-phPRD(2023)·31 citations
24. 24*

    Cluster formation near midrapidity -- can the mechanism be identified experimentally?

    V. Kireyeu🇷🇺 · G. Coci🇩🇪 · S. Glaessel🇩🇪 · J. Aichelin🇫🇷 · C. Blume🇩🇪 · E. Bratkovskaya🇩🇪

    The formation of weakly bound clusters in the hot and dense environment at midrapidity is one of the surprising phenomena observed experimentally in heavy-ion collisions from a low center of mass energy of a few GeV up to a ultra-relativistic energy of several TeV. Three approaches have been advanced to describe the cluster formation: coalescence at kinetic freeze-out, cluster formation during the entire heavy-ion collision by potential interaction between nucleons and deuteron production by hadronic reactions. We identify experimental observables, which can discriminate these production mechanisms for deuterons.

    ↳ nucl-thhep-exhep-phPRC(2024)·19 citations
25. 25*

    Colour-Flavour Locked Quark Stars in Light of the Compact Object in HESS J1731-347 and the GW190814 Event

    P.T. Oikonomou🇬🇷 · Ch.C. Moustakidis🇬🇷

    The central compact object within HESS J1731- 347 possesses unique mass and radius properties that renders it a compelling candidate for a self-bound star. In this research, we examine the capability of quark stars composed of colour superconducting quark matter to explain the latter object by using its marginalised posterior distribution and imposing it as a constraint on the relevant parameter space. Namely, we investigate quark matter for $N_f=2,3$ in the colour superconducting phase, incorporating perturbative QCD corrections, and we derive their properties accordingly. The utilised thermodynamic potential of this work possesses an MIT bag model formalism with the parameters being established as flavour-independent. In this instance, we conclude the favour of 3-flavour over 2-flavour colour superconducting quark matter, isolating our interest on the former. The parameter space is further confined due to the additional requirement for a high maximum mass ($M_{\text{TOV}}\ge 2.6M_{\odot }$), accounting for GW$190814$'s secondary companion. We pay a significant attention on the speed of sound and the trace anomaly (proposed as a measure of conformality [\href{https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.129.252702}{10.1103/PhysRevLett.129.252702}]). We conclude that it is possible for colour-flavour locked quark stars to reach high masses without violating the conformal bound or the $⟨\Theta {⟩}_{{\mu }_B}\ge 0$ if the quartic coefficient value ${\alpha }_4$ does not exceed an upper limit which is solely dependent on the established $M_{\text{TOV}}$. For $M_{\text{TOV}}=2.6M_{\odot }$, we find that the limit reads ${\alpha }_4\le 0.594$. Lastly, a further study takes place on the agreement of colour-flavour locked quark stars with additional astrophysical objects including the GW$170817$ and GW$190425$ events, followed by a relevant discussion.

    ↳ astro-ph.HEhep-phnucl-thPRD(2023)·53 citations
26. 26*

    Constraining the onset density for the QCD phase transition with the neutrino signal from core-collapse supernovae

    Noshad Khosravi Largani🇵🇱 · Tobias Fischer🇵🇱 · Niels Uwe F. Bastian🇵🇱

    The occurrence of a first-order hadron-quark matter phase transition at high baryon densities is investigated in astrophysical simulations of core-collapse supernovae, to decipher yet incompletely understood properties of the dense matter equation of state (EOS) using neutrinos from such cosmic events. It is found that the emission of a nonstandard second neutrino burst, dominated by electron antineutrinos, is not only a measurable signal for the appearance of deconfined quark matter but also reveals information about the state of matter at extreme conditions encountered at the supernova (SN) interior. To this end, a large set of spherically symmetric SN models is investigated, studying the dependence on the EOS and the stellar progenitor. General relativistic neutrino-radiation hydrodynamics is employed featuring three-flavor Boltzmann neutrino transport and a microscopic hadron-quark hybrid matter EOS class. Therefore, the DD2 relativistic mean-field hadronic model is employed, and several variations of it, and the string-flip model for the description of deconfined quark matter. The resulting hybrid model covers a representative range of onset densities for the phase transition and latent heats. This facilitates the direct connection between intrinsic signatures of the neutrino signal and properties of the EOS. In particular, a set of linear relations has been found empirically. These potentially provide a constraint for the onset density of a possible QCD phase transition from the future neutrino observation of the next galactic core-collapse SN, if a millisecond electron anti-neutrino burst is present around or less than 1s.

    ↳ astro-ph.HEhep-phApJ(2024)·22 citations
27. 27*

    How an era of kination impacts substructure and the dark matter annihilation rate

    M. Sten Delos🇩🇪 · Kayla Redmond🇺🇸 · Adrienne L. Erickcek🇺🇸

    An era of kination occurs when the Universe's energy density is dominated by a fast-rolling scalar field. Dark matter that is thermally produced during an era of kination requires larger-than-canonical annihilation cross sections to generate the observed dark matter relic abundance. Furthermore, dark matter density perturbations that enter the horizon during an era of kination grow linearly with the scale factor prior to radiation domination. We show how the resulting enhancement to the small-scale matter power spectrum increases the microhalo abundance and boosts the dark matter annihilation rate. We then use gamma-ray observations to constrain thermal dark matter production during kination. The annihilation boost factor depends on the minimum halo mass, which is determined by the small-scale cutoff in the matter power spectrum. Therefore, observational limits on the dark matter annihilation rate imply a minimum cutoff scale for a given dark matter particle mass and kination scenario. For dark matter that was once in thermal equilibrium with the Standard Model, this constraint establishes a maximum allowed kinetic decoupling temperature for the dark matter. This bound on the decoupling temperature implies that the growth of perturbations during kination cannot appreciably boost the dark matter annihilation rate if dark matter was once in thermal equilibrium with the Standard Model.

    ↳ astro-ph.COhep-phPRD(2023)·11 citations
28. 28*

    Stochastic Description of Near-Horizon Fluctuations in Rindler-AdS

    Yiwen Zhang🇺🇸 · Kathryn M. Zurek🇺🇸

    We study quantum spacetime fluctuations near light-sheet horizons associated with a Rindler wedge in AdS spacetime, in the context of AdS/CFT. In particular, we solve the vacuum Einstein equation near the light-sheet horizon, augmented with the Ansatz of a quantum source smeared out in a Planckian width along one of the light-cone directions. Such a source, whose physical interpretation is of gravitational shockwaves created by vacuum energy fluctuations, alters the Einstein equation to a stochastic partial differential equation taking the form of a Langevin equation. By integrating fluctuations along the light sheet, we find an accumulated effect in the round-trip time of a photon to traverse the horizon of the Rindler wedge that depends on both the $d$-dimensional Newton constant $G_N^{(d)}$ and the AdS curvature $L$, in agreement with previous literature utilizing different methods.

    ↳ hep-thgr-qchep-phPRD(2023)·18 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.