Wed·Sep 6, 2023Wednesday·September 6, 2023

1. 01*

   Search for Lorentz-violation through sidereal effect at NO{\nu}A Experiment

   Shashank Mishra🇮🇳 · Saurabh Shukla🇮🇳 · Lakhwinder Singh🇮🇳 · Venktesh Singh🇮🇳

   Long-baseline neutrino oscillation experiments offer a unique laboratory to test the fundamental Lorentz symmetry, which is heart of both the standard model of particle and general relativity theory. Deviations from the standard neutrino oscillation or the sidereal modulation in neutrino events will smoking-gun experimental signature of Lorentz and CPT violation. In this study, we investigate the impact of the sidereal effect on standard neutrino oscillation measurements within the context of the NO{\nu}A experiment. Additionally, we assess the sensitivity of the NO{\nu}A experiment to detect Lorentz-violating interactions, taking into account the sidereal effect. Furthermore, we highlight potential of the NO{\nu}A experiment to set the new constraints on anisotropic Lorentz-violating parameters.

   hep-phPRD(2024)·10 citations
2. 02*

   On Coherence in Bragg-Primakoff Axion Photoconversion

   Adrian Thompson🇺🇸

   Axions and axion-like pseudoscalar particles with dimension-5 couplings to photons exhibit coherent Bragg-Primakoff scattering with ordered crystals at keV energy scales. This provides for a natural detection technique in searches for axions produce in the Sun's interior. I will motivate the utility of dark matter direct detection experiments in searching for solar axions, emphasizing the role crystal-based detector technologies. I present an updated theoretical treatment of the Bragg-Primakoff photoconversion process for keV pseudoscalars, and address simultaneously the effects of absorption of final state photons in crystals on the loss of coherence, which can lead to large suppressive corrections to the event rate sensitivity for this detection technique. However, I also show that the Borrmann effect of anomalous absorption significantly lifts the suppression. This phenomenon is studied in Ge, NaI, and CsI crystal experiments and its impact on the the projected sensitivities of SuperCDMS, LEGEND, and SABRE to the solar axion parameter space. Lastly, I investigate the future reach of multi-ton scale crystal detectors and discuss strategies to maximize the discovery potential of experimental efforts in this vein.

   hep-ph4 citations
3. 03*

   $2^{++}$ Tensor Di-Gluonium from Laplace Sum Rules at NLO

   S. Li (Dept. Phys, Univ. Saskatchewan, CA)🇨🇦 · S. Narison (LUPM, CNRS-In2P3, Univ. Montpellie, France)🇫🇷 · T. Steele (Dept. Phys, Univ. Saskatchewan, CA)🇨🇦 · D. Rabetiarivony (iHEPMAD, Univ. Antananarivo, Madagascar)🇲🇬

   We evaluate the next-to-leading (NLO) corrections to the perturbative (PT) and $<{\alpha }_s{G}^2>$ condensate and the LO constant term of the $<G^3>$ contributions to the $2^{++}$ tensor di-gluonium two-point correlator. Using these results into the inverse Laplace transform sum rules (LSR) moments and their ratio, we estimate the mass and coupling of the lowest ground state. We obtain\,: $M_T=3028(287)$ MeV and the renormalization group invariant (RGI) coupling ${\hat{f}}_T=224(33)$ MeV within a vacuum saturation estimate of the $D=8$ dimension gluon condensates ($k_G=1$). We study the effect of $k_G$ on the result and find: $M_T=3188(337)$ MeV and ${\hat{f}}_T$=245(32) MeV for $k_G=(3\pm 2)$. Our result does not favour the pure gluonia/glueball nature of the observed $f_2(2010,2300,2340)$ states.

   hep-phhep-exhep-latPLB(2024)·10 citations
4. 04*

   Constraining scotogenic dark matter and primordial black holes using gravitational waves

   Teruyuki Kitabayashi🇯🇵

   The lightest $Z_2$ odd particle in the scotogenic model, referred to as scotogenic dark matter (DM), is a widely studied candidate for DM. This scotogenic DM is generated through well-known thermal processes as well as via the evaporation of primordial black holes (PBHs). Recent reports suggested that the curvature fluctuations of PBHs during an epoch dominated by these entities in the early universe can serve as the source of so-called induced gravitational waves (GWs). In this study, we demonstrate that stringent constraints on the mass of scotogenic DM and PBHs can be obtained through the detection of induced GWs using future detectors.

   hep-phastro-ph.COPhys.Dark Univ.(2024)·2 citations
5. 05*

   Top-Quark Decay at Next-to-Next-to-Next-to-Leading Order in QCD

   Long Chen🇨🇳 · Xiang Chen🇨🇳 · Xin Guan🇨🇳 · Yan-Qing Ma🇨🇳

   We present the first complete high-precision QCD corrections to the inclusive decay width ${\mathrm{\Gamma }}_t$, the $W$-helicity fractions $f_{\mathrm{L},\mathrm{R},0}$ and semi-inclusive distributions for the top-quark decay process $t\to b+W^{+}+X_{\mathrm{QCD}}$ at NNNLO in the strong coupling constant ${\alpha }_s$. In particular, the pure NNNLO QCD correction decreases the ${\mathrm{\Gamma }}_t$ by about $0.8\%$ of the previous NNLO result at the top-quark pole mass scale, exceeding the error estimated by the usual scale-variation prescription. After taking into account all sources of errors, we get ${\mathrm{\Gamma }}_t=1.3148_{-0.005}^{+0.003}+0.027(m_t-172.69)\text{GeV}$, the error of which meets the request by future colliders. On the other hand, the NNNLO QCD effects on $f_{\mathrm{L},\mathrm{R},0}$ are found to be much smaller, at the level of one per-mille for the dominating $f_0$, predestining them to act as precision observables for the top-quark decay process.

   hep-phhep-exPRD(2026)·29 citations
6. 06*

   Insights from the magnetic field dependence of the muonium-to-antimuonium transition

   Takeshi Fukuyama🇯🇵 · Yukihiro Mimura🇯🇵 · Yuichi Uesaka🇯🇵

   The muonium-to-antimuonium transition experiment is about to be updated. Notably, the experiment at J-PARC in Japan can explore the magnetic field dependence of the transition probability. In this paper, we investigate the information that we can extract from the transition probabilities across different magnetic field strengths, while also taking into account a planned transition experiment at CSNS in China. There are two model-independent parameters in the transition amplitude, and we ascertain the feasibility of determining these parameters, including their relative physical phase, from experimental measurements. This physical phase can be related to the electron electric dipole moment, which is severely constrained by experiments. The underlying mediator responsible for the transition can be either doubly charged particles or neutral particles. In the former case, typical magnetic fields yield specific probability ratios, while the latter presents a range of the probability ratio. We investigate several models with neutral mediators, and elucidate that the probability ratio is linked to the sign of new physics contribution to the electron $g-2$. The pivotal role of the J-PARC transition experiment in shedding light on these insights is emphasized.

   hep-phPRD(2023)·5 citations
7. 07*

   Forward proton physics at LHC

   Rafał Staszewski🇵🇱

   Diffractive phenomena constitute a large fraction of interactions occurring in pp collisions at LHC. Because of the non-perturbative nature, their present understanding is still relatively poor and uncertain. One of the methods to study these processes is forward proton tagging. I will discuss the mechanism of diffractive processes, recent results, and potential implications. The proton tagging method can also be used for measurements of photon-induced processes, in particular, the photon-photon interactions. I will present the physics behind these processes, the experimental status and the lessons we can learn for the strong interactions and for the electroweak sector.

   hep-phhep-ex1 citation
8. 08*

   Testing Lorentz invariance violation using cosmogenic neutrinos

   M. A. Reyes🇪🇸 · D. Boncioli🇮🇹 · J. M. Carmona🇪🇸 · J. L. Cortés🇪🇸

   Secondary messengers such as neutrinos and photons are expected to be produced in interactions of ultra-high-energy cosmic rays (UHECRs) with extragalactic background photons. Their propagation could be altered by the effects of Lorentz invariance violation. In this work, we have developed an extension of the SimProp code that includes some Lorentz-violating scenarios affecting the propagation of neutrinos. We present the corresponding expected cosmogenic neutrino fluxes for three different astrophysical scenarios for the production of UHECRs. These results can be used to put constraints on the scale of Lorentz violation in the neutrino sector.

   hep-phastro-ph.HEPoS(2023)·2 citations
9. 09*

   Hadronization dynamics from the spectral representation of the gauge invariant quark propagator

   Caroline S. R. Costa🇺🇸 · Alberto Accardi🇺🇸 · Andrea Signori🇮🇹

   Using the spectral representation of the quark propagator we study the Dirac decomposition of the gauge invariant quark propagator, whose imaginary part describes the hadronization of a quark as this interacts with the vacuum. We then demonstrate the formal gauge invariance of the so-called jet mass, that is of the coefficient of the chiral-odd part of the gauge invariant propagator, that can be expressed in any gauge as the first moment of the chiral-odd quark spectral function. This is therefore revealed to be a \textit{bona fide} QCD observable encoding aspects of the dynamical mass generation in the QCD vacuum, and is furthermore experimentally measurable in specific twist-3 longitudinal-transverse asymmetries in DIS and in semi-inclusive electron-positron collisions. In light-like axial gauges, we also obtain a new sum rule for the spectral function associated with the gauge fixing vector. We finally present a gauge-dependent formula that connects the second moment of the chiral-even coefficient of the quark spectral function to invariant mass generation and final state rescattering in the hadronization of a quark. Finding twist-4 experimental observables sensitive to this quantity is left for future work.

   hep-phnucl-th0 citations
10. 10*

    A POWHEG generator for deep inelastic scattering

    Andrea Banfi🇬🇧 · Silvia Ferrario Ravasio🇨🇭 · Barbara Jäger🇩🇪 · Alexander Karlberg🇨🇭 · Felix Reichenbach🇩🇪 · Giulia Zanderighi🇩🇪

    We present a new event generator for the simulation of both neutral- and charged-current deep inelastic scattering (DIS) at next-to-leading order in QCD matched to parton showers using the POWHEG method. Our implementation builds on the existing POWHEG BOX framework originally designed for hadron-hadron collisions, supplemented by considerable extensions to account for the genuinely different kinematics inherent to lepton-hadron collisions. In particular, we present new momentum mappings that conserve the special kinematics found in DIS, which we use to modify the POWHEG BOX implementation of the Frixione-Kunszt-Signer subtraction mechanism. We compare our predictions to fixed-order and resummed predictions, as well as to data from the HERA ep collider. Finally we study a few representative distributions for the upcoming Electron Ion Collider.

    hep-phhep-exJHEP(2024)·45 citations
11. 11*

    Dispersive analysis of the experimental data on the electromagnetic form factor of charged pions at spacelike momenta

    S. Simula🇮🇹 · L. Vittorio🇫🇷

    The experimental data on the electromagnetic form factor of charged pions available at spacelike momenta are analyzed using the Dispersive Matrix (DM) approach, which describes the momentum dependence of hadronic form factors without introducing any explicit parameterization and includes properly the constraints coming from unitarity and analyticity. The unitary bound is evaluated nonperturbatively making use of the results of lattice QCD simulations of suitable two-point correlation functions contributing to the HVP term of the muon. Thanks to the DM method we determine the pion charge radius from existing spacelike data in a completely model-independent way and consistently with the unitary bound, obtaining $<r_{\pi }{>}_{DM}=0.703\pm 0.027$ fm. This finding differs by $\simeq 1.6$ standard deviations from the latest PDG value $<r_{\pi }{>}_{PDG}=0.659\pm 0.004$ fm, which is dominated by the very precise results of dispersive analyses of timelike data coming from measurements of the cross section of the $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}$ process. We have analyzed the spacelike data using also traditional $z$-expansions, like the Boyd-Grinstein-Lebed (BGL) or Bourrely-Caprini-Lellouch (BCL) fitting functions and adopting a simple procedure that incorporates ab initio the non-perturbative unitary bound in the fitting process. We get $<r_{\pi }{>}_{BGL}=0.711\pm 0.039$ fm and $<r_{\pi }{>}_{BCL}=0.709\pm 0.028$ fm in nice agreement with the DM result. We have addressed also the issue of the onset of perturbative QCD by performing a sensitivity study of the pion form factor at large spacelike momenta, based only on experimental spacelike data and unitarity. Hence, although the leading pQCD behaviour is found to set in only at very large momenta, our DM bands may provide information about the pre-asymptotic effects related to the scale dependence of the pion distribution amplitude.

    hep-phhep-exhep-latPRD(2023)·23 citations
12. 12*

    R&D for Positron Sources at High-Energy Lepton Colliders

    Gudrid Moortgat-Pick🇩🇪 · Sabine Riemann🇩🇪 · Peter Sievers🇨🇭 · Carmen Tenholt🇩🇪

    Several designs for high-energy Lepton Colliders serving as Higgs factories but extendable to higher energies up to the TeV range are under discussion. The most mature design is the International Linear Collider (ILC), but also the Compact Linear Collider (CLIC) as well as the new concept of a Hybrid Asymmetric Linear Higgs Factory (HALHF) have a large physics potential. The first energy stage with $\sqrt{s}=250$~GeV requires high luminosity and polarized beams and imposes an effort for all positron source designs at high-energy colliders. In the baseline design of the ILC, an undulator-based source is foreseen for the positron source in order to match the physics requirements. In this contribution an overview is given about the undulator-based source, the target tests, the rotating target wheel design, as well as the pulsed solenoid and the new technology development of plasma lenses as optic matching devices.

    hep-phhep-exphysics.acc-ph0 citations
13. 13*

    Spectrum of the molecular tetraquarks: Unraveling the $T_{cs0}(2900)$ and $T_{c\bar{s}0}^a(2900)$

    Bo Wang🇨🇳 · Kan Chen🇨🇳 · Lu Meng🇩🇪 · Shi-Lin Zhu🇨🇳

    We relate the interactions of the ${\bar{D}}^{(\ast )}{K}^{\ast }$ and $D^{(\ast )}{K}^{\ast }$ systems to those of $D^{(\ast )}{D}^{(\ast )}$ and $D^{(\ast )}{\bar{D}}^{(\ast )}$ respectively, considering the residual strong interactions at the near-threshold energy is too weak to excite the strange quarks inside the hadrons. We propose an effective model to describe the low-energy S-wave interactions that are undertaken by the light $u$, $d$ quarks between two separated heavy hadrons. We find that the existence of molecules in the heavy-(anti)heavy sectors will naturally lead to the emergence of molecular states in ${\bar{D}}^{(\ast )}{K}^{\ast }$ and $D^{(\ast )}{K}^{\ast }$ systems. The recently observed $T_{cs0}(2900)$ and $T_{c\bar{s}0}^a(2900)$ can be well identified as the $0(0^{+})$ and $1(0^{+})$ partners of $T_{cc}(3875)$ and $Z_c(3900)$ in the charmed strange sector, respectively. We also predict their members under the {\it heavy} ($c$ and $s$) quark symmetry and SU(2) flavor symmetry. Most of them are very good molecule candidates, for example, (i) the $0(1^{+})$ states in $D^{\ast }{D}^{\ast }$, $\bar{D}{K}^{\ast }$, ${\bar{D}}^{\ast }{K}^{\ast }$; (ii) the $0^{(+)}(2^{+(+)})$ states in $D^{\ast }{\bar{D}}^{\ast }$, ${\bar{D}}^{\ast }{K}^{\ast }$, $D^{\ast }{K}^{\ast }$; (iii) the $1^{-}(0^{++})$ state in $D^{\ast }{\bar{D}}^{\ast }$ and $1(1^{+})$ state in $D^{\ast }{K}^{\ast }$. The $0^{+}(0^{++})$ state in $D\bar{D}$ and the $0(1^{+})$ state in $D{K}^{\ast }$ might also exist as virtual states, and the $0(1^{+})$ $D{K}^{\ast }$ can serve as a key to infer the existence of $0^{+}(0^{++})$ $D\bar{D}$. The $D_s\pi$ invariant mass spectrum of $T_{c\bar{s}0}^a(2900)$ is also studied within the coupled-channel approach, and the molecular interpretation of $T_{c\bar{s}0}^a(2900)$ is consistent with the experimental data. Searching for the predicted states in experiments is crucial to discriminate the different pictures for interpreting these near-threshold exotica.

    hep-phhep-exPRD(2024)·39 citations
14. 14*

    Understanding the first measurement of $\mathcal{B}(B\to K\nu \bar{\nu })$

    Lukas Allwicher🇨🇭 · Damir Becirevic🇫🇷 · Gioacchino Piazza🇫🇷 · Salvador Rosauro-Alcaraz🇫🇷 · Olcyr Sumensari🇫🇷

    Recently, Belle II reported on the first measurement of $\mathcal{B}(B^{\pm }\to K^{\pm }\nu \bar{\nu })$ which appears to be almost $3\sigma$ larger than predicted in the Standard Model. We point out the important correlation with $\mathcal{B}(B\to K^{\ast }\nu \bar{\nu })$ so that the measurement of that decay mode could help restraining the possible options for building the model of New Physics. We then try to interpret this new experimental result in terms of physics beyond the Standard Model by using SMEFT and find that a scenario with coupling only to $\tau$ can accommodate the current experimental constraints but fails in getting a desired $R_{D^{(\ast )}}^{\exp }/R_{D^{(\ast )}}^{\mathrm{SM}}$, unless one turns the other SMEFT operators that are not related to $b\to s\ell \ell$ or/and $b\to s\nu \nu$.

    hep-phPLB(2024)·100 citations
15. 15*

    Acceleration of a polarized neutron by internal weak nuclear forces

    M. Donaire🇪🇸

    It is proven that a polarized neutron gets accelerated by internal nuclear forces along the coherent rotation of its spin. The net force upon the neutron arises from the weak nuclear interactions between its quarks. It is the result of the simultaneous breaking of parity symmetry by the chiral interactions between the neutron's quarks, and of time-reversal symmetry along the inversion of their spins. The variation of the neutron's kinetic momentum is accompanied with the transfer of an equivalent momentum to the fields of the Z and W bosons that mediate the interactions, in the opposite direction. The effect is linear in Fermi's constant. Using the simplest hadron models, an upper bound of the order of meters per second is estimated for the velocity variation of the polarized neutron along the spin-flip process.

    hep-phnucl-th1 citation
16. 16*

    SU(3) parity doubling in cold neutron star matter

    Eduardo S. Fraga🇧🇷 · Rodrigo da Mata🇧🇷 · Jürgen Schaffner-Bielich🇩🇪

    We present a phenomenological model to investigate the chiral phase transition characterized by parity doubling in dense, beta equilibrated, cold matter. Our model incorporates effective interactions constrained by SU(3) relations and considers baryonic degrees of freedom. By constraining the model with astrophysical data and nuclear matter properties, we find a first-order phase transition within realistic values of the slope parameter L. The inclusion of the baryon octet and negative parity partners, along with a chiral-invariant mass $m_0$, allows for a non-massless chiral symmetric phase. Through exploration of parameter space, we identify parameter sets satisfying mass and radius constraints without requiring a partonic phase. The appearance of the parity partner of the nucleon, the N(1535) resonance, suppresses strangeness, pushing hyperonization to higher densities. We observe a mild first-order phase transition to the chirally restored phase, governed by $m_0$. Our calculations of surface tension highlight its strong dependence on $m_0$. The existence of mixed phases is ruled out since they become energetically too costly. We compare stars with metastable and stable cores using both branches of the equation of state. Despite limited lifespans due to low surface tension values, phase conversion and star contraction could impact neutron stars with masses around 1.3 solar masses or more. We discuss some applications of this model in its non-zero temperatures generalization and scenarios beyond beta equilibrium that can provide insights into core-collapse supernovae, proto-neutron star evolution, and neutron star mergers. Core-collapse supernovae dynamics, influenced by chiral symmetry restoration and exotic hadronic states, affect explosion mechanisms and nucleosynthesis.

    hep-phastro-ph.HEnucl-thPRD(2023)·17 citations
17. 17*

    Majorana neutrinos in the triple gauge boson coupling $ZZ{Z}^{\ast }$

    Héctor Novales-Sánchez🇲🇽 · Mónica Salinas🇲🇽

    Confirmed by the measurement of neutrino oscillations, neutrino mass is recognized as a genuine manifestation of physics beyond the Standard Model, while its originating mechanism remains a mystery. Moreover, the proper field-theory description of neutrinos, whether they are Majorana or Dirac type, must be linked to such a mechanism. The present work addresses the calculation, estimation, and analysis of one-loop contributions from virtual Majorana neutrinos, light and heavy as well, to the neutral gauge boson coupling $ZZZ$, which participates in $Z$-boson pair production from $e^{+}{e}^{-}$ collisions. This task is carried out in the framework defined by a seesaw variant in which light neutrinos remain massless at tree level, then becoming massive radiatively. The $ZZ{Z}^{\ast }$ coupling, with $Z^{\ast }$ an off-shell $Z$ boson, is defined by two form factors, namely, $f_4$, characterizing CP-odd effects, and $f_5$, which is CP-even. Constraints from the Large Hadron Collider on both these quantities are currently $\mathcal{O}(10^{-4})$. Our calculation yields CP-nonpreserving contributions to $ZZZ$, which are absent in the framework of the sole Standard Model. Our estimations show that the $f_4$ contribution might be as large as $\mathcal{O}(10^{-7})$ for heavy-neutrino masses $\sim 1\mathrm{TeV}$. CP-even contributions $f_5$ are also generated, which are, in general, larger than their CP-odd counterparts. We estimate them to be as large as $\mathcal{O}(10^{-4})$ at a center-of-mass energy of $500\mathrm{GeV}$, in $e^{+}{e}^{-}$ collisions.

    hep-phPRD(2023)·6 citations
18. 18*

    Cosmological Implications of Kalb-Ramond-Like-Particles

    Christian Capanelli🇨🇦 · Leah Jenks🇺🇸 · Edward W. Kolb🇺🇸 · Evan McDonough🇨🇦

    The Kalb-Ramond field is an antisymmetric, rank-two tensor field which most notably appears in the context of string theory, but has largely been unexplored in the context of cosmology. In this work, motivated by the Kalb-Ramond field in string theory, and antisymmetric tensor fields that emerge in effective field theories ranging from particle physics to condensed matter, we study the primordial production of interacting massive Kalb-Ramond-like-particles (KRLPs). KRLPs contain features of both dark photon and axion models, which can be appreciated via their duality properties. While the massless non-interacting KRLP is dual to a pseudoscalar, and the massive non-interacting KRLP is dual to a pseudovector, the interacting massive KRLP can be distinguished from its scalar and vector counterparts. We study early-universe production of KRLPs via the freeze-in mechanism, considering a `dark photon-like' interaction, an `axion-like' interaction, and a `Higgs portal' interaction, as well as production via cosmological gravitational particle production. We find that as a dark matter candidate, KRLPs can be produced by all of the above mechanisms and account for the relic density of dark matter today for a wide range of masses. Finally, we comment on the potential to obtain both warm and cold dark matter subcomponents, and speculate on observational and experimental prospects.

    hep-phastro-ph.COhep-thJHEP(2024)·39 citations
19. 19*

    Dark Matter (H)eats Young Planets

    Djuna Croon🇬🇧 · Juri Smirnov🇬🇧

    We study the effect of dark matter annihilation on the formation of Jovian planets. We show that dark matter heat injections can slow or halt Kelvin-Helmholtz contraction, preventing the accretion of hydrogen and helium onto the solid core. The existence of Jupiter in our solar system can therefore be used to infer constraints on dark matter with relatively strong interaction cross sections. We derive novel constraints on the cross section for both spin-dependent and spin-independent dark matter. We highlight the possibility of a positive detection using future observations by JWST, which could reveal strongly varying planet morpholoiges close to our Galactic Center.

    hep-phastro-ph.EPastro-ph.HEJCAP(2024)·18 citations
20. 20*

    Nucleon axial-vector form factor and radius from future neutrino experiments

    Roberto Petti🇺🇸 · Richard J. Hill🇺🇸 · Oleksandr Tomalak🇺🇸

    Precision measurements of antineutrino elastic scattering on hydrogen from future neutrino experiments offer a unique opportunity to access the low-energy structure of protons and neutrons. We discuss the determination of the nucleon axial-vector form factor and radius from antineutrino interactions on hydrogen that can be collected at the future Long-Baseline Neutrino Facility, and study the sources of theoretical and experimental uncertainties. The projected accuracy would improve existing measurements by $1$ order of magnitude and be competitive with contemporary lattice-QCD determinations, potentially helping to resolve the corresponding tension with measurements from (anti)neutrino elastic scattering on deuterium. We find that the current knowledge of the nucleon vector form factors could be one of the dominant sources of uncertainty. We also evaluate the constraints that can be simultaneously obtained on the absolute ${\bar{\nu }}_{\mu }$ flux normalization.

    hep-phhep-exnucl-exnucl-thPRD(2024)·18 citations
21. 21*

    Status of next-generation ${\Lambda }_b\to p,\Lambda ,{\Lambda }_c$ form-factor calculations

    Stefan Meinel🇺🇸

    I present preliminary results of next-generation lattice-QCD calculations of the ${\Lambda }_b\to p$, ${\Lambda }_b\to \Lambda$, and ${\Lambda }_b\to {\Lambda }_c$ form factors based on RBC/UKQCD gauge-field ensembles with 2+1 flavors of domain-wall fermions. Compared to the work published in 2015 and 2016, the new calculations include three additional ensembles (one with 139 MeV pion mass, one with 0.073 fm lattice spacing, and one with another volume) and were performed with a more accurate tuning of the charm and bottom anisotropic clover action parameters.

    ↳ hep-lathep-phPoS(2024)·12 citations
22. 22*

    Starobinsky inflation with a quadratic Weyl tensor

    Antonio De Felice🇯🇵 · Ryodai Kawaguchi🇯🇵 · Kotaro Mizui🇯🇵 · Shinji Tsujikawa🇯🇵

    In Starobinsky inflation with a Weyl squared Lagrangian $-\alpha C^2$, where $\alpha$ is a coupling constant, we study the linear stability of cosmological perturbations on a spatially flat Friedmann-Lemaître-Robertson-Walker background. In this theory, there are two dynamical vector modes propagating as ghosts for $\alpha >0$, whose condition is required to avoid tachyonic instabilities of vector perturbations during inflation. The tensor sector has four propagating degrees of freedom, among which two of them correspond to ghost modes. However, the tensor perturbations approach constants after the Hubble radius crossing during inflation, and hence the classical instabilities are absent. In the scalar sector, the Weyl curvature gives rise to a ghost mode coupled to the scalaron arising from the squared Ricci scalar. We show that two gauge-invariant gravitational potentials, which are both dynamical in our theory, are subject to exponential growth after the Hubble radius crossing. There are particular gauge-invariant combinations like the curvature perturbations whose growth is suppressed, but it is not possible to remove the instability of other propagating degrees of freedom present in the perturbed metric. This violent and purely classical instability present in the scalar sector makes the background unviable. Furthermore, the presence of such classical instability makes the quantization of the modes irrelevant, and the homogeneous inflationary background is spoiled by the Weyl curvature term.

    ↳ gr-qcastro-ph.COhep-phhep-thPRD(2023)·20 citations
23. 23*

    Far-from-equilibrium bulk-viscous transport coefficients in neutron star mergers

    Yumu Yang🇺🇸 · Mauricio Hippert🇺🇸 · Enrico Speranza🇺🇸 · Jorge Noronha🇺🇸

    We investigate the weak-interaction-driven bulk-viscous transport properties of $npe$ matter in the neutrino transparent regime. Previous works assumed that the induced bulk viscosity correction to pressure, near beta equilibrium, is linear in deviations from the equilibrium charge fraction. We show that this is not always true for (some) realistic equations of state at densities between one and three times saturation density. This nonlinear nature of the perturbation around equilibrium motivates a far-from-beta-equilibrium description of bulk-viscous transport in neutron star mergers, which can be precisely achieved using a new Israel-Stewart formulation with resummed bulk and relaxation time transport coefficients. The computation of these transport coefficients depends on out-of-beta-equilibrium pressure corrections, which can be computed for a given equation of state. We calculate these coefficients for equations of state that satisfy the latest constraints from multi-messenger observations from LIGO/VIRGO and NICER. We show that varying the nuclear symmetry energy $J$ and its slope $L$ can significantly affect the transport coefficients and the nonlinear behavior of the out-of-equilibrium pressure corrections. Therefore, having better constraints on $J$ and $L$ will directly impact our understanding of bulk-viscous processes in neutron star mergers.

    ↳ nucl-thastro-ph.HEhep-phPRC(2024)·39 citations
24. 24*

    Reconstruction of Unstable Heavy Particles Using Deep Symmetry-Preserving Attention Networks

    Michael James Fenton🇺🇸 · Alexander Shmakov🇺🇸 · Hideki Okawa🇨🇳 · Yuji Li🇨🇳 · Ko-Yang Hsiao🇹🇼 · Shih-Chieh Hsu🇺🇸 · Daniel Whiteson🇺🇸 · Pierre Baldi🇺🇸

    Reconstructing unstable heavy particles requires sophisticated techniques to sift through the large number of possible permutations for assignment of detector objects to the underlying partons. Anapproach based on a generalized attention mechanism, symmetry preserving attention networks (SPA-NET), has been previously applied to top quark pair decays at the Large Hadron Collider which produce only hadronic jets. Here we extend the SPA-NET architecture to consider multiple input object types, such as leptons, as well as global event features, such as the missing transverse momentum. Inaddition, we provide regression and classification outputs to supplement the parton assignment. We explore the performance of the extended capability of SPA-NET in the context of semi-leptonic decays of top quark pairs as well as top quark pairs produced in association with a Higgs boson. We find significant improvements in the power of three representative studies: a search for ttH, a measurement of the top quark mass, and a search for a heavy Z' decaying to top quark pairs. We present ablation studies to provide insight on what the network has learned in each case.

    ↳ hep-excs.LGhep-phCommun.Phys.(2024)·21 citations
25. 25*

    Dark Matter Velocity Distributions: Comparing Numerical Simulations to Analytic Results

    Katharena Christy🇺🇸 · Jason Kumar🇺🇸 · Louis E. Strigari🇺🇸

    We test the consistency of dark matter velocity distributions obtained from dark matter-only numerical simulations with analytic predictions, using the publicly available Via Lactea 2 dataset as an example. We find that, well inside the scale radius, the velocity distribution obtained from numerical simulation is consistent with a function of a single integral of motion -- the energy -- and moreover is consistent with the result obtained from Eddington inversion. This indicates that the assumptions underlying the analytic result, namely, spherical symmetry, isotropy, and a static potential, are sufficiently accurate to govern the coarse properties of the velocity distribution in the inner regions of the halo. We discuss implications for the behavior of the high-velocity tail of the distribution, which can dominate dark matter annihilation from a $p$- or $d$-wave state.

    ↳ astro-ph.COhep-phPRD(2024)·5 citations
26. 26*

    Generalization of Instanton-Induced Inflation and Dynamical Compactification

    Jeongwon Ho🇰🇷 · Kyung Kiu Kim🇰🇷 · Seoktae Koh🇰🇷 · Hyun Seok Yang🇰🇷

    It was shown that Yang-Mills instantons on an internal space can trigger the expansion of our four-dimensional universe as well as the dynamical compactification of the internal space. We generalize the instanton-induced inflation and dynamical compactification to general Einstein manifolds with positive curvature and also to the FLRW metric with spatial curvature. We explicitly construct Yang-Mills instantons on all Einstein manifolds under consideration and find that the homogeneous and isotropic universe is allowed only if the internal space is homogeneous. We then consider the FLRW metric with spatial curvature as a solution of the eight-dimensional Einstein-Yang-Mills theory. We find that open universe $(k=-1)$ admits bouncing solutions unlike the other cases $(k=0,+1)$.

    ↳ hep-thgr-qchep-phJHEP(2023)·3 citations
27. 27*

    Constraints on Axion-like Particles from Observations of Mrk 421 using the $\mathrm{C}{\mathrm{L}}_{\mathrm{s}}$ Method

    Lin-Qing Gao🇨🇳 · Xiao-Jun Bi🇨🇳 · Jun-Guang Guo🇨🇳 · Wenbin Lin🇨🇳 · Peng-Fei Yin🇨🇳

    Axion-like particles (ALPs) may undergo mixing with photons in the presence of astrophysical magnetic fields, leading to alterations in the observed high energy $\gamma$-ray spectra. In this study, we investigate the ALP-photon oscillation effect using the spectra of the blazar Mrk 421 over 15 observation periods measured by Major Atmospheric Gamma Imaging Cherenkov Telescopes (MAGIC) and Fermi Large Area Telescope (Fermi-LAT). Compared with previous studies, we generate mock data under the ALP hypothesis and employ the $\mathrm{C}{\mathrm{L}}_{\mathrm{s}}$ method to set constraints on the ALP parameters. This method is widely utilized in high energy experiments and avoids the exclusion of specific parameter regions where distinguishing between the null and ALP hypotheses is challenging. We find that the ALP-photon coupling $g_{a\gamma }$ is constrained to be smaller than $\sim 2\times 10^{-11}$ GeV${}^{-1}$ for ALP masses ranging from $10^{-9}$ eV to $10^{-7}$ eV at the 95\% confidence level. We also present the constraints derived from the TS distribution under the null hypothesis, which is commonly utilized in previous astrophysical ALP studies. Our results reveal that the combined constraints of all the periods obtained from both methods are consistent. However, the $\mathrm{C}{\mathrm{L}}_{\mathrm{s}}$ method remains effective in cases where the latter method fails to provide constraints for specific observation periods.

    ↳ astro-ph.HEhep-phPRD(2024)·15 citations
28. 28*

    Multi-messenger signatures of delayed choked jets in tidal disruption events

    Mainak Mukhopadhyay🇺🇸 · Mukul Bhattacharya🇺🇸 · Kohta Murase🇺🇸

    Recent radio observations and coincident neutrino detections suggest that some tidal disruption events (TDEs) exhibit late-time activities, relative to the optical emission peak, and these may be due to delayed outflows launched from the central supermassive black hole. We investigate the possibility that jets launched with a time delay of days to months, interact with a debris that may expand outwards. We discuss the effects of the time delay and expansion velocity on the outcomes of jet breakout and collimation. We find that a jet with an isotropic-equivalent luminosity of $\lesssim 5\times 10^{45}erg/s$ is likely to be choked for a delay time of $\sim 3$ months. We also study the observational signatures of such delayed choked jets. The jet-debris interaction preceding the breakout would lead to particle acceleration and the resulting synchrotron emission can be detected by current and near-future radio, optical and X-ray telescopes, and the expanding jet-driven debris could explain late-time radio emission. We discuss high-energy neutrino production in delayed choked jets, and the time delay can significantly alleviate the difficulty of the hidden jet scenario in explaining neutrino coincidences.

    ↳ astro-ph.HEhep-phMNRAS(2024)·13 citations
29. 29*

    Implications of correlations and fluctuations in small systems

    Debasish Das🇮🇳

    The small collision systems like p+p and p+A collisions have shown new features like A+A collisions in the relativistic regime. These new aspects in small systems which have altered our research and understanding on the two-particle correlation measurements have been provided. Additionally, a critical observation of the fluctuation measurements provides new ways to infer such novel happening in the small collision systems. The ongoing and future endeavors towards the new measurements are also discussed.

    ↳ nucl-exhep-exhep-phnucl-thInt.J.Mod.Phys.A(2022)·1 citation
30. 30*

    Disentangling the primordial nature of stochastic gravitational wave backgrounds with CMB spectral distortions

    Bryce Cyr🇬🇧 · Thomas Kite🇬🇧 · Jens Chluba🇬🇧 · J. Colin Hill🇺🇸 · Donghui Jeong🇺🇸 · Sandeep Kumar Acharya🇬🇧 · Boris Bolliet🇬🇧 · Subodh P. Patil🇳🇱

    The recent detection of a stochastic gravitational wave background (SGWB) at nanohertz frequencies by pulsar timing arrays (PTAs) has sparked a flurry of interest. Beyond the standard interpretation that the progenitor is a network of supermassive black hole binaries, many exotic models have also been proposed, some of which can potentially offer a better fit to the data. We explore how the various connections between gravitational waves and CMB spectral distortions can be leveraged to help determine whether a SGWB was generated primordially or astrophysically. To this end, we present updated $k$-space window functions which can be used for distortion parameter estimation on enhancements to the primordial scalar power spectrum. These same enhancements can also source gravitational waves (GWs) directly at second order in perturbation theory, so-called scalar-induced GWs (SIGWs), and indirectly through the formation of primordial black holes (PBHs). We perform a mapping of scalar power spectrum constraints into limits on the GW parameter space of SIGWs for $\delta$-function features. We highlight that broader features in the scalar spectrum can explain the PTA results while simultaneously producing a spectral distortion (SD) within reach of future experiments. We additionally update PBH constraints from $\mu$- and $y$-type spectral distortions. Refined treatments of the distortion window functions widen existing SD constraints, and we find that a future CMB spectrometer could play a pivotal role in unraveling the origin of GWs imprinted at or below CMB anisotropy scales.

    ↳ astro-ph.COgr-qchep-phMNRAS(2024)·60 citations
31. 31*

    Holography of Linear Dilaton Spacetimes from the Bottom Up

    Sylvain Fichet🇧🇷 · Eugenio Megias🇪🇸 · Mariano Quiros🇪🇸

    The linear dilaton background is the keystone of a string-derived holographic correspondence beyond AdS${}_{d+1}$/CFT${}_d$. This motivates an exploration of the $(d+1)$-dimensional linear dilaton spacetime (LD${}_{d+1}$) and its holographic properties from the low-energy viewpoint. We first notice that the LD${}_{d+1}$ space has simple conformal symmetries, that we use to shape an effective field theory (EFT) on the LD background. We then place a brane in the background to study holography at the level of quantum fields and gravity. We find that the holographic correlators from the EFT feature a pattern of singularities at certain kinematic thresholds. We argue that such singularities can be used to bootstrap the putative $d$-dimensional dual theory using techniques analogous to those of the Cosmological Bootstrap program. Turning on finite temperature, we study the holographic fluid emerging on the brane in the presence of a bulk black hole. We find that the holographic fluid is pressureless for any $d$ due to a cancellation between Weyl curvature and dilaton stress tensor, and verify consistency with the time evolution of the theory. From the fluid thermodynamics, we find a universal temperature and Hagedorn behavior for any $d$. This matches the properties of a CFT${}_2$ with large $T\overline{T}$ deformation, and of little string theory for $d=6$. Both the fluid equation of state and the spectrum of quantum fluctuations suggest that the $d$-dimensional dual theory arising from LD${}_{d+1}$ is generically gapped.

    ↳ hep-thgr-qchep-phPRD(2024)·18 citations
32. 32*

    More solutions for the Wheeler-DeWitt equation in a flat FLRW minisuperspace

    Chia-Min Lin🇨🇳

    This work proposes more solutions for the Wheeler-DeWitt equation in a flat FLRW minisuperspace. We study quantum cosmology in the framework of the de Broglie-Bohm interpretation and investigate the quantum cosmological effects throughout the evolution of the universe. In a particular solution, the tendency for a scalar field to roll down the potential is balanced by the quantum force, and a Minkowski spacetime is obtained.

    ↳ gr-qcastro-ph.COhep-phhep-thGen.Rel.Grav.(2024)·1 citation

* 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.