Mon·Apr 3, 2023Monday·April 3, 2023

1. 01*

   Detecting Nanometer-Scale New Forces with Coherent Neutron Scattering

   Zachary Bogorad🇺🇸 · Peter W. Graham🇺🇸 · Giorgio Gratta🇺🇸

   Significant effort has been devoted to searching for new fundamental forces of nature. At short length scales (below approximately 10 nm), the strongest experimental constraints come from neutron scattering from individual nuclei in gases. The leading experiments at longer length scales instead measure forces between macroscopic test masses. We propose a hybrid of these two approaches: scattering neutrons off of a target that has spatial structure at nanoscopic length scales. Such structures will give a coherent enhancement to small-angle scattering, where the new force is most significant. This can considerably improve the sensitivity of neutron scattering experiments for new forces in the 0.1 - 100 nm range. We discuss the backgrounds due to Standard Model interactions and a variety of potential target structures that could be used, estimating the resulting sensitivities. We show that, using only one day of beam time at a modern neutron scattering facility, our proposal has the potential to detect new forces as much as two orders of magnitude beyond current laboratory constraints at the appropriate length scales.

   hep-phhep-exnucl-exPRD(2023)·8 citations
2. 02*

   Two-component model description of Bose-Einstein correlations in pp collisions at 13 TeV measured by the CMS Collaboration at the LHC

   Takuya Mizoguchi🇯🇵 · Seiji Matsumoto🇯🇵 · Minoru Biyajima🇯🇵

   Using the two-component model, we analyze Bose-Einstein correlations in pp collisions at the center-of-mass energy of 13 TeV, measured by the CMS Collaboration at the LHC, and compare results with the $\tau$-model. We utilize data described by the double ratios with an average pair transverse momentum $0\le k_T\le 1.0$ GeV and six intervals described by the reconstructed charged particle multiplicity as $N_{\mathrm{trk}}^{\mathrm{offline}}$. The estimated ranges are 1-4 fm for the magnitude of extension of emitting source expressed by the exponential function $\exp (-RQ)$ and 0.4-0.5 fm for that by the Gaussian distribution $\exp (-(RQ{)}^2))$, respectively. Moreover, we estimate the upper limits of the 3-pion BEC to test the two-component model and investigate the role of the long-range correlation.

   hep-phPRD(2023)·2 citations
3. 03*

   Description of the newly observed ${\Omega }_c^{\ast }$ states as molecular states

   Jingwen Feng🇨🇳 · Feng Yang🇨🇳 · Cai Cheng🇨🇳 · Yin Huang🇨🇳

   In this work, we study the strong decays of the newly observed ${\Omega }_c^{\ast }(3185)$ and ${\Omega }_c^{\ast }(3327)$ assuming that ${\Omega }_c^{\ast }(3185)$ and ${\Omega }_c^{\ast }(3327)$ as $S$-wave $D\Xi$ and $D^{\ast }\Xi$ molecular state, respectively. Since the ${\Omega }_c^{\ast }$ was observed in the ${\Xi }_c^{+}{K}^{-}$ invariant mass distributions, the partial decay width of ${\Omega }_c^{\ast }(3185)$ and ${\Omega }_c^{\ast }(3327)$ into ${\Xi }_c^{+}{K}^{-}$ through hadronic loops are evaluated with the help of the effective Lagrangians. Moreover, the decay channel of ${\Xi }_c^{{}^{\prime }}\bar{K}$ is also included. The decay process is described by the $t$-channel $\Lambda$, $\Sigma$ baryons and $D_s$, $D_s^{\ast }$ mesons exchanges, respectively. By comparison with the LHCb observation, the current results support the ${\Omega }_c^{\ast }(3327)$ with$J^P=3/2^{-}$ as pure $D^{\ast }\Xi$ molecule while the ${\Omega }_c^{\ast }(3327)$ with $J^P=1/2^{-}$ can not be well reproduced in the molecular state picture. In addition, the spin-parity $J^P=1/2^{-}$ $D\Xi$ molecular assumptions for the ${\Omega }_c^{\ast }(3185)$ can't be conclusively determined. It may be a meson-baryon molecule with a big $D\Xi$ component. Although the decay width of the ${\Omega }_c^{\ast }\to \bar{K}{\Xi }_c^{{}^{\prime }}$ is of the order several MeV, it can be well employed to test the molecule interpretations of ${\Omega }_c^{\ast }(3185)$ and ${\Omega }_c^{\ast }(3327)$.

   hep-ph11 citations
4. 04*

   B-meson hadroproduction in the SACOT-$m_{\mathrm{T}}$ scheme

   Ilkka Helenius🇫🇮 · Hannu Paukkunen🇫🇮

   We apply the SACOT-$m_{\mathrm{T}}$ general-mass variable flavour number scheme (GM-VFNS) to the inclusive B-meson production in hadronic collisions at next-to-leading order in perturbative Quantum Chromodynamics. In the GM-VFNS approach one matches the fixed-order heavy-quark production cross sections, accurate at low transverse momentum ($p_{\mathrm{T}}$), with the zero-mass cross sections, accurate at high $p_{\mathrm{T}}$. The physics idea of the SACOT-$m_{\mathrm{T}}$ scheme is to do this by accounting for the finite momentum transfer required to create a heavy quark-antiquark pair throughout the calculation. We compare our results with the latest LHC data from proton-proton and proton-lead collisions finding a very good agreement within the estimated theoretical uncertainties. We discuss also scheme-related differences and their impact on the scale uncertainties.

   hep-phJHEP(2023)·25 citations
5. 05*

   Quantum Theory of Dark Matter Scattering

   Ayuki Kamada🇵🇱 · Takumi Kuwahara🇨🇳 · Ami Patel🇵🇱

   Dark matter self-scattering is one of key ingredients for small-scale structure of the Universe, while dark matter annihilation is important for the indirect measurements. There is a strong correlation between the velocity-dependent self-scattering cross section and the Sommerfeld enhancement factor for the dark matter annihilation cross section. In this study, we formulate a direct relation between them by the use of Watson's (initial state/final state) theorem and Omnès solution, and our formulation reproduces the Sommerfeld enhancement factor, which directly computed by solving the Schrödinger equation, from the scattering phase shift.

   hep-phJHEP(2023)·11 citations
6. 06*

   Maximal temperature of strongly-coupled dark sectors

   H. Kolesova🇳🇴 · M. Laine🇨🇭 · S. Procacci🇨🇭

   Taking axion inflation as an example, we estimate the maximal temperature ($T_{\max }^{}$) that can be reached in the post-inflationary universe, as a function of the confinement scale of a non-Abelian dark sector (${\Lambda }_{\mathrm{IR}}^{}$). Below a certain threshold ${\Lambda }_{\mathrm{IR}}^{}<{\Lambda }_0^{}\sim 2\times 10_{}^{-8}{m}_{\mathrm{pl}}^{}$, the system heats up to $T_{\max }^{}\sim {\Lambda }_0^{}>T_{\mathrm{c}}^{}$, and a first-order thermal phase transition takes place. On the other hand, if ${\Lambda }_{\mathrm{IR}}^{}>{\Lambda }_0^{}$, then $T_{\max }^{}\sim {\Lambda }_{\mathrm{IR}}^{}<T_{\mathrm{c}}^{}$: very high temperatures can be reached, but there is no phase transition. If the inflaton thermalizes during heating-up (which we find to be unlikely), or if the plasma includes light degrees of freedom, then heat capacity and entropy density are larger, and $T_{\max }^{}$ is lowered towards ${\Lambda }_0^{}$. The heating-up dynamics generates a gravitational wave background. Its contribution to $N_{\mathrm{eff}}^{}$ at GHz frequencies, the presence of a monotonic $\sim f_0^3$ shape at $(10_{}^{-4}-10_{}^2)$Hz frequencies, and the frequency domain of peaked features that may originate via first-order phase transitions, are discussed.

   hep-phastro-ph.COJHEP(2023)·12 citations
7. 07*

   Are we close to solving the puzzle of weak radiative hyperon decays?

   Rui-Xiang Shi🇨🇳 · Li-Sheng Geng🇨🇳

   The BESIII experiment at the Beijing Electron Positron collider, run as a ``hyperon factory'', recently reported the first measurement of the asymmetry parameter of the $\Lambda \to n\gamma$ decay and updated its branching fraction, which differs from the PDG average by 5.6 sigma. We highlight the impact of this new measurement on our understanding of the puzzle of weak radiative hyperon decays and pinpoint what needs to be done in the future.

   hep-phhep-exhep-latSci.Bull.(2023)·6 citations
8. 08*

   Probing darK Matter Using free leptONs: PKMUON

   Alim Ruzi🇨🇳 · Chen Zhou🇨🇳 · Xiaohu Sun🇨🇳 · Dayong Wang🇨🇳 · Siguang Wang🇨🇳 · Yong Ban🇨🇳 · Yajun Mao🇨🇳 · Qite Li🇨🇳 · Qiang Li🇨🇳

   We propose a new method to detect sub-GeV dark matter, through their scatterings from free leptons and the resulting kinematic shifts. Specially, such an experiment can detect dark matter interacting solely with muons. The experiment proposed here is to directly probe muon-philic dark matter, in a model-independent way. Its complementarity with the muon on target proposal, is similar to, e.g. XENON/PandaX and ATLAS/CMS on dark matter searches. Moreover, our proposal can work better for relatively heavy dark matter such as in the sub-GeV region. We start with a small device of a size around 0.1 to 1 meter, using atmospheric muons to set up a prototype. Within only one year of operation, the sensitivity on cross section of dark matter scattering with muons can already reach ${\sigma }_D\sim 10^{-19(-20,-18)}{\mathrm{cm}}^2$ for a dark mater ${\mathrm{M}}_{\mathrm{D}}=100(10,1000)$ MeV. We can then interface the device with a high intensity muon beam of $10^{12}$/bunch. Within one year, the sensitivity can reach ${\sigma }_D\sim 10^{-27(-28,-26)}{\mathrm{cm}}^2$ for ${\mathrm{M}}_{\mathrm{D}}=100(10,1000)$ MeV.

   hep-phastro-ph.HEhep-exInt.J.Mod.Phys.A(2023)·7 citations
9. 09*

   A sensitivity study of triboson production processes to dimension-6 EFT operators at the LHC

   Riccardo Bellan🇮🇹 · Saptaparna Bhattacharya🇺🇸 · Giacomo Boldrini🇮🇹 · Flavia Cetorelli🇮🇹 · Pietro Govoni🇮🇹 · Andrea Massironi🇮🇹 · Alberto Mecca🇮🇹 · Cristiano Tarricone🇮🇹 · Antonio Vagnerini🇮🇹

   We present the first parton-level study of anomalous effects in triboson production in both fully and semi-leptonic channels in proton-proton collisions at 13 TeV at the Large Hadron Collider (LHC). The sensitivity to anomalies induced by a minimal set of bosonic dimension-6 operators from the Warsaw basis is evaluated with specific analyses for each final state. A likelihood-based strategy is employed to assess the most sensitive kinematic observables per channel, where the contribution of Effective Field Theory operators is parameterized at either the linear or quadratic level. The impact of the mutual interference terms of pairs of operators on the sensitivity is also examined. This benchmark study explores the complementarity and overlap in sensitivity between different triboson measurements and paves the way for future analyses at the LHC experiments. The statistical combination of the considered final states allows setting stringent bounds on five bosonic Wilson coefficients.

   hep-phhep-exJHEP(2023)·11 citations
10. 10*

    Isospin-conserving hadronic decay of the $D_{s1}(2460)$ into $D_s{\pi }^{+}{\pi }^{-}$

    Meng-Na Tang🇨🇳 · Yong-Hui Lin🇩🇪 · Feng-Kun Guo🇨🇳 · Christoph Hanhart🇩🇪 · Ulf-G. Meißner🇩🇪

    The internal structure of the charm-strange mesons $D_{s0}^{\ast }(2317)$ and $D_{s1}(2460)$ are subject of intensive studies. Their widths are small because they decay dominantly through isospin-breaking hadronic channels $D_{s0}^{\ast }(2317{)}^{+}\to D_s^{+}{\pi }^0$ and $D_{s1}(2460{)}^{+}\to D_s^{\ast +}{\pi }^0$. The $D_{s1}(2460)$ can also decay into the hadronic final states $D_s^{+}\pi \pi$, conserving isospin. In that case there is, however, a strong suppression from phase space. We study the transition $D_{s1}(2460{)}^{+}\to D_s^{+}{\pi }^{+}{\pi }^{-}$ in the scenario that the $D_{s1}(2460)$ is a $D^{\ast }K$ hadronic molecule. The $\pi \pi$ final state interaction is taken into account through dispersion relations. We find that the ratio of the partial widths of the $\Gamma (D_{s1}(2460{)}^{+}\to D_s^{+}{\pi }^{+}{\pi }^{-})/\Gamma (D_{s1}(2460{)}^{+}\to D_s^{\ast +}{\pi }^0)$ obtained in the molecular picture is consistent with the existing experimental measurement. More interestingly, we demonstrate that the ${\pi }^{+}{\pi }^{-}$ invariant mass distribution shows a double bump structure, which can be used to disentangle the hadronic molecular picture from the compact state picture for the $D_{s1}(2460{)}^{+}$. Predictions on the $B_{s1}^0\to B_s^0{\pi }^{+}{\pi }^{-}$ are also made.

    hep-phhep-exCommun.Theor.Phys.(2023)·20 citations
11. 11*

    Soft pattern of Rutherford scattering from heavy target mass expansion

    Yu Jia🇨🇳 · Jia-Yue Zhang🇨🇳

    We investigate the soft behavior of the tree-level Rutherford scattering process. We consider two types of Rutherford scattering, a low-energy massless point-like projectile (say, a spin-$\frac{1}{2}$ or spin-$0$ electron) to hit a static massive composite target particle carrying various spins (up to spin-$2$), and a slowly-moving light projectile hits a heavy static composite target. For the first type, the unpolarized cross sections in the laboratory frame are found to exhibit universal forms in the first two orders of $1/M$ expansion, yet differ at the next-to-next-to-leading order (though some terms at this order still remain to be universal or depend on the target spin in a definite manner). For the second type, at the lowest order in electron velocity expansion, through all orders in $1/M$, the unpolarized cross section is universal (also not sensitive to the projectile spin). The universality partially breaks down at relative order-$v^2/M^2$, though some terms at this order are still universal or depend on the target spin in a specific manner. We also employ the effective field theory approach to reproduce the soft behavior of the differential cross sections for the target particle being a composite Dirac fermion.

    hep-phCPC(2025)·1 citation
12. 12*

    The Importance of Flavor in SMEFT Electroweak Precision Fits

    Luigi Bellafronte🇪🇸 · Sally Dawson🇺🇸 · Pier Paolo Giardino🇪🇸

    Effective field theory tools are essential for exploring non-Standard Model physics at the LHC in the absence of the discovery of new light particles. Predictions for observables are typically made at the lowest order in the QCD and electroweak expansions in the Standard Model effective field theory (SMEFT) and often ignore the effects of flavor. Here, we present results for electroweak precision observables (EWPOs)at the next-to-leading order QCD and electroweak expansions (NLO) of the SMEFT with an arbitrary flavor structure for the fermion operators. Numerical NLO SMEFT fits toEWPOs have a strong dependence on the assumed flavor structures and we demonstrate this using various popular assumptions for flavor symmetries.

    hep-phJHEP(2023)·49 citations
13. 13*

    Sensitivity to Supernovae Average ${\nu }_x$ Temperature with Neutral Current Interactions in DUNE

    Darcy A. Newmark🇺🇸 · Austin Schneider🇺🇸

    We explore a novel method for measuring the average temperature of the ${\nu }_x$ component in Type-II core-collapse supernovae. By measuring neutral current incoherent neutrino-Argon interactions in DUNE we can obtain spectral information for the combination of all active neutrino species. Combining this all-neutrino spectral information with detailed charged current measurements of the electron neutrino and electron anti-neutrino fluxes from DUNE and Hyper-Kamiokande, we can infer the average temperature for the remaining neutrino species in the ${\nu }_x$ component to within a factor two for most cases and to 30% for a small range of average ${\nu }_x$ temperatures. Due to the limited energy range of the emitted photons from incoherent neutral current interactions on Argon, the ${\nu }_x$ temperature reconstruction demonstrates a degeneracy in the one and two sigma credible regions. Furthermore, while large uncertainties on the NC cross-section penalize this measurement, we examined the efficacy of constraining NC cross-section uncertainties on improving ${\nu }_x$ measurements. We found that if additional measurements of B(M1$\uparrow$) 1${}^{+}$ excited state transitions in Argon are able to reduce correlated cross section uncertainties from 15% to 7%, the size of the $1\sigma$ allowed regions for $T_{{\nu }_x}$ becomes sample size limited, and approaches the case where there are no uncertainties on the cross-section.

    hep-phPRD(2023)·7 citations
14. 14*

    Connecting $(g-2{)}_{\mu }$ to neutrino mass in the extended neutrinophilic 2HDM

    A. L. Cherchiglia🇧🇷 · G. De Conto🇧🇷 · C. C. Nishi🇧🇷

    One simple way to lower the scale of the seesaw mechanism that generates neutrino masses is to attribute part of their smallness to a suppressed vacuum expectation value of a second Higgs doublet as in the neutrinophilic 2HDM or in the type IB seesaw model. On that structure we add one charged singlet scalar to induce a chirally enhanced contribution to $(g-2{)}_{\mu }$ with the same righthanded neutrinos of the seesaw. We discuss the interplay of generating the necessary contribution to the latter with lepton flavor violation which is also necessarily brought to low scale. We show that it is possible to explain $(g-2{)}_{\mu }$ even for heavy neutrino masses of order of a few TeV.

    hep-phJHEP(2023)·8 citations
15. 15*

    On the Relations between Fermion Masses and Isospin Couplings in the Microscopic Model

    Bodo Lampe🇩🇪

    Quark and lepton masses and mixings are considered in the framework of the microscopic model. The most general ansatz for the interactions among tetrons leads to a Hamiltonian $H_T$ involving Dzyaloshinskii-Moriya (DM), Heisenberg and torsional isospin forces. Diagonalization of the Hamiltonian provides for 24 eigenvalues which are identified as the quark and lepton masses. While the masses of the third and second family arise from DM and Heisenberg type of isospin interactions, light family masses are related to torsional interactions among tetrons. Neutrino masses turn out to be special in that they are given in terms of tiny isospin non-conserving DM, Heisenberg and torsional couplings. The approach not only leads to masses, but also allows to calculate the quark and lepton eigenstates, an issue, which is important for the determination of the CKM and PMNS mixing matrices. Compact expressions for the eigenfunctions of $H_T$ are given. The almost exact isospin conservation of the system dictates the form of the lepton states and makes them independent of all the couplings in $H_T$. Much in contrast, there is a strong dependence of the quark states on the coupling strengths, and a promising hierarchy between the quark families shows up.

    hep-phFortsch.Phys.(2024)·0 citations
16. 16*

    Polarization Formalism for ALP-induced X-ray Emission from Magnetars

    Jean-François Fortin🇨🇦 · Kuver Sinha🇺🇸

    Missions like NASA's Imaging X-ray Polarimetry Explorer (IXPE) are poised to provide an unprecedented view of the Universe in polarized X-rays. Polarization probes physical anisotropies, a fact exploited by particle physicists to look for the anisotropic $a\mathbf{E}\cdot \mathbf{B}$ operator in the axion-like-particle (ALP) Lagrangian. Such studies have typically focused on polarization in the radio and microwaves, through local or cosmic birefringence effects. To such polarization studies we add X-rays emanating from magnetars -- a class of neutron stars with near-critical strength magnetic fields -- that are important targets for IXPE. ALPs produced in the neutron star core convert to X-rays in the magnetosphere; such X-rays are polarized along the direction parallel to the dipolar magnetic field at the point of conversion. We develop the full theoretical formalism for ALP-induced polarization in the presence of dipolar magnetic fields. For uncorrelated photon and ALP production mechanisms, we completely disentangle the ALP contributions to the Stokes parameters in terms of the ALP intensity, the ALP-to-photon conversion probability, and the ALP-induced birefringence. In the proper limit, our results demonstrate that the inclusion of ALPs suppresses the observed degree of circular polarization compared to its pure astrophysical value. Our results can also be used to impose limits on ALP couplings with IXPE polarization data from magnetars 4U 0142+61 and 1RXS J170849.0-400910, the subject of upcoming work.

    ↳ astro-ph.HEhep-phJCAP(2023)·7 citations
17. 17*

    The cosmological constant is probably still zero

    Yang Liu🇬🇧 · Antonio Padilla🇬🇧 · Francisco G. Pedro🇮🇹

    We consider a wide class of four-dimensional effective field theories in which gravity is coupled to multiple four-forms and their dual scalar fields, with membrane sources charged under the corresponding three-form potentials. Four-form flux, quantised in units of the membrane charges, generically generates a landscape of vacua with a range of values for the cosmological constant that is scanned through membrane nucleation. We list various ways in which the landscape can be made sufficiently dense to be compatible with observations of the current vacuum without running into the empty universe problem. Further, we establish the general criteria required to ensure the absolute stability of the Minkowski vacuum under membrane nucleation and the longevity of those vacua that are parametrically close by. This selects the current vacuum on probabilistic grounds and can even be applied in the classic model of Bousso and Polchinski, albeit with some mild violation of the membrane weak gravity conjecture. We present other models where the membrane weak gravity conjecture is not violated but where the same probabilistic methods can be used to tackle the cosmological constant problem.

    ↳ hep-thastro-ph.COgr-qchep-phJHEP(2023)·9 citations
18. 18*

    Stringy scaling of n-point Regge string scattering amplitudes

    Sheng-Hong Lai🇹🇼 · Jen-Chi Lee🇹🇼 · Yi Yang🇹🇼

    We discover a stringy scaling behavior for a class of n-point Regge string scattering amplitudes (RSSA). The number of independent kinematics variables is found to be reduced by dim M.

    ↳ hep-thhep-phmath-phmath.MPJHEP(2023)·5 citations
19. 19*

    Mass varying dark matter and its cosmological signature

    Anirban Das🇰🇷 · Subinoy Das🇮🇳 · Shiv K. Sethi🇮🇳

    Nontrivial dark sector physics continues to be an interesting avenue in our quest to the nature of dark matter. In this paper, we study the cosmological signatures of mass-varying dark matter where its mass changes from zero to a nonzero value in the early Universe. We compute the changes in various observables, such as, the linear matter power spectrum and the cosmic microwave background anisotropy power spectrum. We explain the origin of the effects and point out a qualitative similarity between this model and a warm dark matter cosmology with no sudden mass transition. Finally, we do a simple analytical study to estimate the constraint on the parameters of this model from the Lyman-$\alpha$ forest data.

    ↳ astro-ph.COhep-phPRD(2023)·9 citations
20. 20*

    Inflationary gravitational wave background as a tail effect

    Niko Jokela🇫🇮 · K. Kajantie🇫🇮 · M. Laine🇨🇭 · Sami Nurmi🇫🇮 · Miika Sarkkinen🇫🇮

    The free propagator of a massless mode in an expanding universe can be written as a sum of two terms, a lightcone and a tail part. The latter describes a subluminal (time-like) signal. We show that the inflationary gravitational wave background, influencing cosmic microwave background polarization, and routinely used for constraining inflationary models through the so-called $r$ ratio, originates exclusively from the tail part.

    ↳ gr-qcastro-ph.COhep-phPRD(2023)·2 citations
21. 21*

    Could compact stars in globular clusters constrain dark matter?

    Raghuveer Garani🇮🇹 · Nirmal Raj🇮🇳 · Javier Reynoso-Cordova🇮🇹

    The dark matter content of globular clusters, highly compact gravity-bound stellar systems, is unknown. It is also generally unknow*able*, due to their mass-to-light ratios typically ranging between 1$-$3 in solar units, accommodating a dynamical mass of dark matter at best comparable to the stellar mass. That said, recent claims in the literature assume densities of dark matter around 1000 GeV/cm${}^3$ to set constraints on its capture and annihilation in white dwarfs residing in the globular cluster M4, and to study a number of other effects of dark matter on compact stars. Motivated by these studies, we use measurements of stellar kinematics and luminosities in M4 to look for a dark matter component via a spherical Jeans analysis; we find no evidence for it, and set the first empirical limits on M4's dark matter distribution. Our density upper limits, a few $\times 10^4$ GeV/cm${}^3$ at 1 parsec from the center of M4, do not negate the claims (nor confirm them), but do preclude the use of M4 for setting limits on non-annihilating dark matter kinetically heating white dwarfs, which require at least $10^5$ GeV/cm${}^3$ densities. The non-robust nature of globular clusters as dynamical systems, combined with evidence showing that they may originate from molecular gas clouds in the absence of dark matter, make them unsuitable as laboratories to unveil dark matter's microscopic nature in current or planned observations.

    ↳ astro-ph.HEastro-ph.GAhep-phJCAP(2023)·17 citations
22. 22*

    Scale-Invariant Model for Gravitational Waves and Dark Matter

    Alexandros Karam🇪🇪 · Maciej Kierkla🇵🇱 · Bogumiła Świeżewska🇵🇱

    We have conducted a revised analysis of the first-order phase transition that is associated with symmetry breaking in a classically scale-invariant model that has been extended with a new $SU(2)$ gauge group. By incorporating recent developments in the understanding of supercooled phase transitions, we were able to calculate all of its features and significantly limit the parameter space. We were also able to predict the gravitational wave spectra generated during this phase transition and found that this model is well-testable with LISA. Additionally, we have made predictions regarding the relic dark matter abundance. Our predictions are consistent with observations but only within a narrow part of the parameter space. We have placed significant constraints on the supercool dark matter scenario by improving the description of percolation and reheating after the phase transition, as well as including the running of couplings. Finally, we have also analyzed the renormalization-scale dependence of our results.

    ↳ astro-ph.COhep-phhep-thPoS(2023)·1 citation
23. 23*

    New Angles on Fast Calorimeter Shower Simulation

    Sascha Diefenbacher🇩🇪 · Engin Eren🇩🇪 · Frank Gaede🇩🇪 · Gregor Kasieczka🇩🇪 · Anatolii Korol🇩🇪 · Katja Krüger🇩🇪 · Peter McKeown🇩🇪 · Lennart Rustige🇩🇪

    The demands placed on computational resources by the simulation requirements of high energy physics experiments motivate the development of novel simulation tools. Machine learning based generative models offer a solution that is both fast and accurate. In this work we extend the Bounded Information Bottleneck Autoencoder (BIB-AE) architecture, designed for the simulation of particle showers in highly granular calorimeters, in two key directions. First, we generalise the model to a multi-parameter conditioning scenario, while retaining a high degree of physics fidelity. In a second step, we perform a detailed study of the effect of applying a state-of-the-art particle flow-based reconstruction procedure to the generated showers. We demonstrate that the performance of the model remains high after reconstruction. These results are an important step towards creating a more general simulation tool, where maintaining physics performance after reconstruction is the ultimate target.

    ↳ physics.ins-dethep-exhep-phphysics.data-anMach.Learn.Sci.Tech.(2023)·48 citations
24. 24*

    Hydrodynamical constraints on bubble wall velocity

    Tomasz Krajewski🇵🇱 · Marek Lewicki🇵🇱 · Mateusz Zych🇵🇱

    Terminal velocity reached by bubble walls in first order phase transitions is an important parameter determining both primordial gravitational-wave spectrum and production of baryon asymmetry in models of electroweak baryogenesis. We developed a numerical code to study the real-time evolution of expanding bubbles and investigate how their walls reach stationary states. Our results agree with profiles obtained within the so-called bag model with very good accuracy, however, not all such solutions are stable and realised in dynamical systems. Depending on the exact shape of the potential there is always a range of wall velocities where no steady state solutions exist. This behaviour in deflagrations was explained by hydrodynamical obstruction where solutions that would heat the plasma outside the wall above the critical temperature and cause local symmetry restoration are forbidden. For even more affected hybrid solutions causes are less straight forward, however, we provide a simple numerical fit allowing one to verify if a solution with a given velocity is allowed simply by computing the ratio of the nucleation temperature to the critical one for the potential in question.

    ↳ astro-ph.COhep-phPRD(2023)·38 citations
25. 25*

    Speeding up Madgraph5 aMC@NLO through CPU vectorization and GPU offloading: towards a first alpha release

    Andrea Valassi🇨🇭 · Taylor Childers🇺🇸 · Laurence Field🇨🇭 · Stephan Hageböck🇨🇭 · Walter Hopkins🇺🇸 · Olivier Mattelaer🇧🇪 · Nathan Nichols🇺🇸 · Stefan Roiser🇨🇭 · David Smith🇨🇭 · Jorgen Teig🇨🇭 · Carl Vuosalo🇺🇸 · Zenny Wettersten🇨🇭

    The matrix element (ME) calculation in any Monte Carlo physics event generator is an ideal fit for implementing data parallelism with lockstep processing on GPUs and vector CPUs. For complex physics processes where the ME calculation is the computational bottleneck of event generation workflows, this can lead to large overall speedups by efficiently exploiting these hardware architectures, which are now largely underutilized in HEP. In this paper, we present the status of our work on the reengineering of the Madgraph5_aMC@NLO event generator at the time of the ACAT2022 conference. The progress achieved since our previous publication in the ICHEP2022 proceedings is discussed, for our implementations of the ME calculations in vectorized C++, in CUDA and in the SYCL framework, as well as in their integration into the existing MadEvent framework. The outlook towards a first alpha release of the software supporting QCD LO processes usable by the LHC experiments is also discussed.

    ↳ physics.comp-phhep-exhep-phJ.Phys.Conf.Ser.(2026)·21 citations
26. 26*

    Searching for dark matter subhalos in the Fermi-LAT catalog with Bayesian neural networks

    Anja Butter🇩🇪 · Michael Krämer🇩🇪 · Silvia Manconi🇩🇪 · Kathrin Nippel🇩🇪

    About a third of the $\gamma$-ray sources detected by the Fermi Large Area Telescope (Fermi-LAT) remain unidentified, and some of these could be exotic objects such as dark matter subhalos. We present a search for these sources using Bayesian neural network classification methods applied to the latest 4FGL-DR3 Fermi-LAT catalog. We first simulate the $\gamma$-ray properties of dark matter subhalos using models from N-body simulations and semi-analytical approaches to the subhalo distribution. We then assess the detectability of this sample in the 4FGL-DR3 catalog using the Fermi-LAT analysis tools. We train our Bayesian neural network to identify candidate dark matter subhalos among the unidentified sources in the 4FGL-DR3 catalog. Our results allow us to derive conservative bounds on the dark matter annihilation cross section by excluding unidentified sources classified as astrophysical-like by our networks. We estimate the number of candidate dark matter subhalos for different dark matter masses and provide a publicly available list for further investigation. Our bounds on the dark matter annihilation cross section are comparable to previous results and become particularly competitive at high dark matter masses.

    ↳ astro-ph.HEhep-phJCAP(2023)·8 citations
27. 27*

    The shadow and gamma-ray bursts of a Schwarzschild black hole in asymptotic safety

    Yuxuan Shi🇨🇳 · Hongbo Cheng🇨🇳

    We research on the neutrino pair annihilation $\nu +\overline{\nu }⟶e^{-}+e^{+}$ around a massive source in asymptotic safety. Since neutrinos and photons have the same geodesic equation around black holes, we can estimate the radius where the neutrinos will be released by obtaining a series of trajectory curves with various correction values $\xi$. The black hole shadow radius is influenced by the correction parameter $\xi$. The black hole shadow radius decreases with increasing the $\xi$. The ratio $\frac{\dot{Q}}{{\dot{Q}}_{Newt}}$ corresponding to the energy deposition per unit time over that in the Newtonian case is derived and calculated. We find that the quantum corrections to the black hole spacetime affect the emitted energy rate ratio for the annihilation. It is interesting that the more considerable quantum effect reduces the ratio value slightly. Although the energy conversion is damped because of the quantum correction, the energy deposition rate is enough during the neutrino-antineutrino annihilation. The corrected annihilation process can become a source of gamma ray burst. We also investigate the derivative $\frac{\mathrm{d}\dot{Q}}{\mathrm{d}r}$ relating to the star's radius $r$ to show that the quantum effect for the black hole will drop the ratio. The more manifest quantum gravity influence leads the weaker neutrino pair annihilation.

    ↳ gr-qchep-phhep-thCommun.Theor.Phys.(2025)·13 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.