Thu·Mar 30, 2023Thursday·March 30, 2023

1. 01*

   Optimal Mass Variables for Semivisible Jets

   Kevin Pedro🇺🇸 · Prasanth Shyamsundar🇺🇸

   Strongly coupled hidden sector theories predict collider production of invisible, composite dark matter candidates mixed with standard model hadrons in the form of semivisible jets. Classical mass reconstruction techniques may not be optimal for these unusual topologies, in which the missing transverse momentum comes from massive particles and has a nontrivial relationship to the visible jet momentum. We apply the artificial event variable network, a semisupervised, interpretable machine learning technique that uses an information bottleneck, to derive superior mass reconstruction functions for several cases of resonant semivisible jet production. We demonstrate that the technique can extrapolate to unknown signal model parameter values. We further demonstrate the viability of conducting an actual search for new physics using this method, by applying the learned functions to standard model background events from quantum chromodynamics.

   hep-phSciPost Phys.Core(2023)·9 citations
2. 02*

   Vacuum birefringence and dichroism in a strong plane-wave background

   I. A. Aleksandrov🇷🇺 · V. M. Shabaev🇷🇺

   In the present study, we consider the effects of vacuum birefringence and dichroism in strong electromagnetic fields. According to quantum electrodynamics, the vacuum state exhibits different refractive properties depending on the probe photon polarization and one also obtains different probabilities of the photon decay via production of electron-positron pairs. Here we investigate these two phenomena by means of several different approaches to computing the polarization operator. The external field is assumed to be a linearly polarized plane electromagnetic wave of arbitrary amplitude and frequency. Varying the probe-photon energy and the field parameters, we thoroughly examine the validity of the locally-constant field approximation (LCFA) and techniques involving perturbative expansions in terms of the external-field amplitude. Within the latter approach, we develop a numerical method based on a direct evaluation of the weak-field Feynman diagrams, which can be employed for investigating more complex external backgrounds. It is demonstrated that the polarization operator depends on two parameters: classical nonlinearity parameter $\xi$ and the product $\eta =\omega q_0/m^2$ of the laser field frequency $\omega$ and the photon energy $q_0$ ($m$ is the electron mass). The domains of validity of the approximate techniques in the $\xi \eta$ plane are explicitly identified.

   hep-ph5 citations
3. 03*

   Spontaneous vacuum decay in low-energy collisions of heavy nuclei beyond the monopole approximation

   Popov R. V.🇷🇺 · Shabaev V. M.🇷🇺 · Maltsev I. A.🇷🇺 · Telnov D. A.🇷🇺 · Dulaev N. K.🇷🇺 · Tumakov D. A🇷🇺

   The problem of spontaneous vacuum decay in low-energy collisions of heavy nuclei is considered beyond the scope of the monopole approximation. The time-dependent Dirac equation is solved in a rotating coordinate system with $z$-axis directed along the internuclear line and the origin placed at the center of mass. The probabilities of electron-positron pair creation and the positron energy spectra are calculated in the approximation neglecting the rotational coupling. The two-center potential is expanded over spherical harmonics and the convergence with respect to the number of terms in this expansion is studied. The results show that taking into account the two-center potential instead of its spherically symmetric part preserves all the signatures of the transition to the supercritical regime that have been found in the framework of the monopole approximation and even enhances some of them.

   hep-phPRD(2023)·10 citations
4. 04*

   High-energy dipole scattering amplitude from evolution of low-energy proton light-cone wave functions

   Adrian Dumitru🇺🇸 · Heikki Mäntysaari🇫🇮 · Risto Paatelainen🇫🇮

   The forward scattering amplitude of a small dipole at high energies is given in the mean field approximation by the Balitsky-Kovchegov (BK) evolution equation. It requires an initial condition $N(r;x_0)$ describing the scattering of a dipole with size $r$ off the target that is probed at momentum fraction $x_0$. Rather than using ad hoc parameterizations tuned to high-energy data at $x\ll x_0$, here we attempt to construct an initial scattering amplitude that is consistent with low-energy, large-$x$ properties of the proton. We start from a non-perturbative three quark light-cone model wave function from the literature. We add $\mathcal{O}(g)$ corrections due to the emission of a gluon, and $\mathcal{O}(g^2)$ virtual corrections due to the exchange of a gluon, computed in light-cone perturbation theory with exact kinematics. We provide numerical data as well as analytic parameterizations of the resulting $N(r;x_0)$ for $x_0=0.01-0.05$. Solving the BK equation in the leading logarithmic (LL) approximation towards lower $x$, we obtain a fair description of the charm cross section in deeply inelastic scattering measured at HERA by fitting one parameter, the coupling constant ${\alpha }_s\simeq 0.2$. However, without the option to tune the initial amplitude at $x_0$, the fit of the high precision data results in ${\chi }^2/N_{\text{dof}}=2.3$ at $N_{\text{dof}}=38$, providing clear statistical evidence for the need of systematic improvement e.g. of the photon wave function, evolution equation, and initial condition.

   hep-phnucl-thPRD(2023)·15 citations
5. 05*

   Renormalon Subtraction in OPE by Dual Space Approach: Nonlinear Sigma Model and QCD

   Yuuki Hayashi🇯🇵 · Go Mishima🇯🇵 · Yukinari Sumino🇯🇵 · Hiromasa Takaura🇯🇵

   It is becoming more important to subtract renormalons efficiently from perturbative calculations, in order to achieve high precision QCD calculations. We propose a new framework ``Dual Space Approach" for renormalon separation, which enables subtraction of multiple renormalons simultaneously. Using a dual transform which suppresses infrared renormalons, we derive a one-parameter integral representation of a general observable. We investigate systematically how renormalons emerge and get canceled in the entire operator product expansion (OPE) of an observable, by applying the expansion-by-regions (EBR) method to this one-parameter integral expression. In particular we investigate in detail OPEs in a solvable model, the 2-dimensional $O(N)$ nonlinear $\sigma$ model, by the dual space approach. A nontrivial mechanism of renormalon cancellation in this model can be understood from an integration identity on which the EBR method is founded. We demonstrate that the dual space approach can be useful by a simulation study imitating the QCD case. Application of this method to QCD calculations is also discussed.

   hep-phhep-thJHEP(2023)·6 citations
6. 06*

   Type-II seesaw Complex Triplet Model: Phase Transition and A Global Fit Analysis

   Yong Du🇨🇳

   The type-II seesaw model can explain neutrino masses and address the baryon asymmetry problem of the Universe simultaneously. In this letter, we explore its phase transition and the resulting gravitational wave signals. We find a strong first-order electroweak phase transition generically prefers a relatively light triplet in the $300\sim 500$GeV range, which is ideal for collider searches and can generate gravitational waves within the sensitivity reach of BBO and Ultimate-DECIGO. While above $\sim$1TeV where a future 100TeV $pp$ collider will play a key role in model discovery, we integrate out the triplet and perform a global fit analysis of this model at various future colliders. A lower bound in the $10^{-3}\sim 10^{-2}$eV range on the triplet vacuum expectation value is obtained, which is comparable to or even better than that from current $\mu \to e\gamma$ experiments depending on the lightest neutrino mass.

   hep-phhep-exNucl.Part.Phys.Proc.(2023)·0 citations
7. 07*

   Coupling Sum Rules and Oblique Corrections in Gauge-Higgs Unification

   Yutaka Hosotani🇯🇵 · Shuichiro Funatsu🇯🇵 · Hisaki Hatanaka🇯🇵 · Yuta Orikasa🇨🇿 · Naoki Yamatsu🇹🇼

   In GUT inspired $SO(5)\times U(1{)}_X\times SU(3{)}_C$ gauge-Higgs unification (GHU) in the Randall-Sundrum warped spacetime, the $W$ and $Z$ couplings of all 4D fermion modes become nontrivial. The $W$ and $Z$ couplings of zero-mode quarks and leptons slightly deviate from those in the SM, and the couplings take the matrix form in the space of Kaluza-Klein (KK) states. In particular, the 4D couplings and mass spectra in the KK states depend on the Aharonov-Bohm phase ${\theta }_H$ in the fifth dimension. Nevertheless there emerge three astonishing sum rules among those coupling matrices, which guarantees the finiteness of certain combinations of corrections to vacuum polarization tensors. We confirm by numerical evaluation that the equality in the sum rules holds with 5 to 7 digits accuracy. Based on the sum rules we propose improved oblique parameters in GHU. Oblique corrections due to fermion 1-loop diagrams are found to be small.

   hep-phPTEP(2023)·4 citations
8. 08*

   Axion Like Particle Search at Higgs Factories

   Kingman Cheung🇹🇼 · C.J. Ouseph🇹🇼

   We study the potential of the future Higgs factories, including the ILC, CEPC, and FCC-ee with $\sqrt{s}$ = 240-250 GeV on discovering axion-like particles (ALPs) through various production channels in the leptonic final states, $e^{+}{e}^{-}\to f\bar{f}a$, where $f=e,\mu ,\nu$. We show that the $e^{+}{e}^{-}\to e^{+}{e}^{-}a$ with $a\to \gamma \gamma$ provides the best bounds for the $g_{a\gamma \gamma }$ and $g_{aZZ}$ couplings, while $e^{+}{e}^{-}\to \nu \bar{\nu }a$, with $a\to \gamma \gamma$ offers the best bounds for the $g_{aZZ}$ and $g_{aZ\gamma }$ couplings. The $e^{+}{e}^{-}\to {\mu }^{+}{\mu }^{-}a$ with $a\to \gamma \gamma$ provides intermediate sensitivity to the $g_{aZZ}$ coupling. Our estimates of the bounds for the $g_{a\gamma \gamma }$, $g_{aZ\gamma }$, and $g_{aZZ}$ couplings as a function of ALP mass ($M_a$) ranging from 0.1 GeV to 100 GeV provide valuable insights for future experiments aiming to detect ALPs. We find that $g_{a\gamma \gamma }$ around $1.5\times 10^{-4}\mathrm{Ge}{\mathrm{V}}^{-1}$ for $M_a=0.1-6$ GeV is currently not ruled out by any other experiments.

   hep-phhep-exPRD(2023)·19 citations
9. 09*

   Quark mixing angles and weak CP-violating phase vs quark masses: potential approach

   Boris Altshuler🇷🇺

   It is shown that following experimentally viable expressions for quark mixing angles ${\theta }_{12}$, ${\theta }_{23}$, ${\theta }_{13}$ and CP-violating phase $\delta$: $\sin {\theta }_{12}=\sqrt{m_d/|m_s|}$, $\sin {\theta }_{23}=2|m_s|/m_b$, $\sin {\theta }_{13}\approx 2m_d/m_b$, $\tan \delta =m_b^2{m}_c/6m_t{m}_s^2$ may be derived as stable points of certain 4-th power in $V_{CKM}$ flavor-invariant potentials built with traces of 3x3 quark up and down mass matrices and the Jarlskog invariant. There is no fine-tuning, potentials' dimensionless constants are the integer numbers not above 10.

   hep-phInt.J.Mod.Phys.A(2023)·2 citations
10. 10*

    $Z,W^{\pm }$ rapidity distributions at NNLL and beyond

    Goutam Das🇩🇪

    In this article, we have studied threshold effects on rapidity distributions of massive gauge bosons ($Z,W^{\pm }$) in the Standard Model at the Large Hadron Collider. By exploiting the universal behavior of soft gluon emissions in the threshold region, we resum the large threshold logarithms arising in the rapidity distribution at next-to-next-to leading logarithmic accuracy and match them to next-to-next-to leading order in QCD. We adapt the double Mellin approach to resum both threshold variables corresponding to partonic threshold and rapidity consistently within the standard QCD framework. Furthermore, we have studied in detail the numerical impact of these threshold effects on the rapidity distribution of massive gauge bosons and found a better perturbative convergence in the resummed rapidity spectrum. As a by-product, we also provide all the perturbative ingredients to extend the analysis to next-to-next-to-next-to leading logarithmic accuracy. As a first application of these third order ingredients, we have estimated their effects by matching them with the third order soft-virtual results. Our results will be useful to understand and possibly constrain parton distributions using the rapidity spectrum.

    hep-ph10 citations
11. 11*

    T violation and the dark sector

    R. Vilela Mendes🇵🇹

    It is argued, as a working hypothesis, that "normal" and dark matter interactions can only be T and CP violating. One way to implement this idea is to consider that time reversal in dark matter is implemented, not by an antiunitary operator, but by a unitary operator. It is shown how this occurs naturally in the context of complex spacetime with an extended symmetry group.

    hep-phastro-ph.HEMod.Phys.Lett.A(2023)·4 citations
12. 12*

    Investigating the potential of $R_{K^{(\ast )}}^{\tau \mu }$ to probe lepton flavor universality violation

    Ashutosh Kumar Alok🇮🇳 · Neetu Raj Singh Chundawat🇮🇳 · Arindam Mandal🇮🇳

    In this work we study the potential of the lepton flavor ratios $R_K^{\tau \mu }\equiv \Gamma (B\to K{\tau }^{+}{\tau }^{-})/\Gamma (B\to K{\mu }^{+}{\mu }^{-})$ and $R_{K^{\ast }}^{\tau \mu }\equiv \Gamma (B\to K^{\ast }{\tau }^{+}{\tau }^{-})/\Gamma (B\to K^{\ast }{\mu }^{+}{\mu }^{-})$ to probe lepton flavor universality (LFU) violation in $\tau -\mu$ sector. We show that these ratios can deviate from their SM values even if the new physics couplings are universal in nature, i.e., having equal couplings to $e$, $\mu$ and $\tau$ leptons. Therefore in order to utilize these observables to probe LFU violation, we need to compare the allowed range of $R_{K^{(\ast )}}^{\tau \mu }$ for class of solutions with only universal couplings to leptons and solutions having both universal and non-universal components. For the current $b\to s\ell \ell$ ($\ell =e,\mu$) data, we find that these two class of solutions can be discriminated provided the measured value of $R_{K^{\ast }}^{\tau \mu }$ is greater than the SM prediction.

    hep-phhep-exPLB(2023)·12 citations
13. 13*

    Yet another QFT model of neutrino oscillations

    Walter Grimus🇦🇹

    We consider a quantum field theory (QFT) model of neutrino oscillations in vacuum that attempts to take into account that the neutrino source particle and the neutrino detection particle both interact with their respective environments by collisions. Our model is minimal in a twofold sense. Firstly we simply assume that neutrino production and detection take place in between collisions in time intervals $\Delta t$ and $\tau$, respectively. Secondly, we only introduce the two wave packets that are absolutely necessary which are those of the neutrino source and the neutrino detection particle. Within this model we find that, for all practical purposes, there are no decoherence effects in the neutrino oscillation amplitude and oscillations occur in space not in time. Moreover, our model leads to the correct time correlation between neutrino production and detection and to a factorization of the event rate of the compound neutrino production--detection process into decay rate, oscillation probability and detection cross section.

    hep-ph5 citations
14. 14*

    Heavy quarkonium with finite three momentum near $T_c$

    HyungJoo Kim🇰🇷 · Seokwoo Yeo🇰🇷 · Sungtae Cho🇰🇷 · Su Houng Lee🇰🇷

    We investigate the non-trivial 3-momentum effects on the masses of heavy quarkonium states that are moving in a hot medium using QCD sum rules. For all charmonium states, we observe a negative mass shift near $T_c$ that is less than 3$\%$ at a momentum of 1$\mathrm{GeV}$. Specifically, we first investigate the difference between the longitudinal and transverse modes of both $J/\psi$ and ${\chi }_{c1}$. We find that the transverse mode of the $J/\psi$ experiences larger modification than the longitudinal mode, while the ${\chi }_{c1}$ has the opposite behavior. By comparing the ${\eta }_c$ and ${\chi }_{c0}$, and also the unpolarized $J/\psi$ and ${\chi }_{c1}$, we recognize that the P-wave particles have stronger momentum dependencies on their masses than the S-wave ones. We also find ${\rm Y}$(1S) has negligible 3-momentum dependence compared to the charmonium states, e.g. less than 0.01$\%$ even at 1.4$T_c$ and at a momentum of 4$\mathrm{GeV}$.

    hep-phhep-exnucl-thPRD(2023)·3 citations
15. 15*

    Effects of finite volume and magnetic fields on thermodynamic properties of quark matter and fluctuations of conserved charges

    Nisha Chahal🇮🇳 · Suneel Dutt🇮🇳 · Arvind Kumar🇮🇳

    In the current work, we present the influence of finite volume and magnetic field on the thermodynamic properties of isospin asymmetric quark matter using the Polyakov loop extended chiral SU(3) quark mean field (PCQMF) model at finite chemical potential and temperature. Within the PCQMF model, we use the scalar and vector field values in mean-field approximation to obtain the thermodynamic properties: pressure density, entropy density and energy density. The susceptibilities of conserved charges for strongly interacting matter for different system sizes as well as for different values of the magnetic field have been studied. A sizable shift in phase boundary towards the higher values of quark chemical potential (${\mu }_q$) and temperature (T) has been observed for decreasing values of system volume as well as an opposite shift towards lower temperature and quark chemical potential for increasing magnetic field. We observe an enhancement in fluctuations of conserved charges in the regime of the transition temperature. These studies may have a significant role in understanding the thermodynamic observables extracted from heavy-ion collisions data.

    hep-phnucl-thPRC(2023)·17 citations
16. 16*

    The Standard Model effective field theory at work

    Gino Isidori🇨🇭 · Felix Wilsch🇨🇭 · Daniel Wyler🇨🇭

    The striking success of the Standard Model in explaining precision data and, at the same time, its lack of explanations for various fundamental phenomena, such as dark matter or the baryon asymmetry of the universe, suggests new physics at an energy scale much larger than the electroweak scale. In the absence of a short-range-long-range conspiracy, the Standard Model can be viewed as the leading term of an effective "remnant" theory (referred to as the SMEFT) of a more fundamental structure. Over the last years, many aspects of the SMEFT have been investigated and it has become a standard tool to analyze experimental results in an integral way. In this article, after briefly presenting the salient features of the Standard Model, we review the construction of the SMEFT. We discuss the range of its applicability and bounds on its coefficients imposed by general theoretical considerations. Since new physics models are likely to exhibit exact or approximate accidental global symmetries, especially in the flavor sector, we also discuss their implications for the SMEFT. The main focus of our review is the phenomenological analysis of experimental results. We show explicitly how to use various effective field theories to study the phenomenology of theories beyond the Standard Model. We give a detailed description of the matching procedure and the use of the renormalization group equations, allowing to connect multiple effective theories valid at different energy scales. Explicit examples from low-energy experiments and from high-$p_T$ physics illustrate the workflow. We also comment on the non-linear realization of the electroweak symmetry breaking and its phenomenological implications.

    hep-phRMP(2024)·229 citations
17. 17*

    Effect of Coriolis force on the shear viscosity of quark matter: A nonrelativistic description

    Cho Win Aung🇮🇳 · Ashutosh Dwibedi🇮🇳 · Jayanta Dey🇮🇳 · Sabyasachi Ghosh🇮🇳

    Shear viscosity becomes anisotropic in a rotating medium. It is discovered here that for rotating thermalized quantum systems such as those created in relativistic heavy-ion collisions, the coeffficient of shear viscosity breaks up into five independent components. Similar phenomena were also discovered for quark-gluon plasma in the presence of the magnetic field. Like the Lorentz force at a finite magnetic field, the Coriolis force also creates anisotropic viscosity at nonzero rotation. As a first approach, for simplicity, the calculations are done in the nonrelativistic prescription, with a future proposal to extend it toward a relativistic description. Introducing the Coriolis force term in relaxation time approximated Boltzmann transport equation, we have found different effective relaxation times along the parallel, perpendicular, and Hall directions in terms of actual relaxation time and rotating time period. Comparing the present formalism with the finite magnetic field picture, we have shown the equivalence of roles between the rotating and cyclotron time periods, where the rotating time period is inverse of twice the angular velocity.

    ↳ nucl-thcond-mat.stat-mechhep-phPRC(2024)·11 citations
18. 18*

    Stringy Threshold Corrections in D-brane Systems

    Satoshi Iso🇯🇵 · Noriaki Kitazawa🇯🇵 · Takao Suyama🇯🇵

    We investigate string amplitudes by using the partial modular transformation which we introduced in our previous works. This enables us to extract stringy threshold corrections from the full string amplitudes and interpret them in terms of the Wilsonian effective field theory in a natural way. We calculate mass shifts and wave function renormalizations for massless scalar fields on brane-antibrane systems. We find that the mass shift can be exponentially small and negative. We also propose a strategy for realizing a hierarchical mass spectrum on D-branes.

    ↳ hep-thhep-phPRD(2023)·0 citations
19. 19*

    Dimensionally-dependent uncertainty relations, or why we (probably) won't see micro-black holes at the LHC, even if large extra dimensions exist

    Matthew J. Lake🇩🇪 · Shi-Dong Liang🇨🇳 · Anucha Watcharapasorn🇹🇭

    We present a simple gedanken experiment in which a compact object traverses a spacetime with three macroscopic spatial dimensions and $n$ compact dimensions. The compactification radius is allowed to vary, as a function of the object's position in the four-dimensional space, and we show that the conservation of gravitational self-energy implies the dimensional dependence of the mass-radius relation. In spacetimes with extra dimensions that are compactified at the Planck scale, no deviation from the four-dimensional result is found, but, in spacetimes with extra dimensions that are much larger than the Planck length, energy conservation implies a deviation from the normal Compton wavelength formula. The new relation restores the symmetry between the Compton wavelength and Schwarzschild radius lines on the mass-radius diagram and precludes the formation of black holes at TeV scales, even if large extra dimensions exist. We show how this follows, intuitively, as a direct consequence of the increased gravitational field strength at distances below the compactification scale. Combining these results with the heuristic identification between the Compton wavelength and the minimum value of the position uncertainty, due to the Heisenberg uncertainty principle, suggests the existence of generalised, higher-dimensional uncertainty relations. These relations may be expected to hold for self-gravitating quantum wave packets, in higher-dimensional spacetimes, with interesting implications for particle physics and cosmology in extra-dimensional scenarios.

    ↳ gr-qchep-phFront.Astron.Space Sci.(2023)·2 citations
20. 20*

    Scalar spectral functions from the spectral fRG

    Jan Horak🇩🇪 · Friederike Ihssen🇩🇪 · Jan M. Pawlowski🇩🇪 · Jonas Wessely🇩🇪 · Nicolas Wink🇩🇪

    We compute non-perturbative spectral functions in a scalar ${\varphi }^4$-theory in three spacetime dimensions via the spectral functional renormalisation group. This approach allows for the direct, manifestly Lorentz covariant computation of correlation functions in Minkowski spacetime, including a physical on-shell renormalisation. We present numerical results for the spectral functions of the two- and four-point correlation functions for different values of the coupling parameter. These results agree very well with those obtained from another functional real-time approach, the spectral Dyson-Schwinger equation.

    ↳ hep-thhep-phPRD(2024)·23 citations
21. 21*

    Fast radio burst energy function in the presence of $\mathrm{D}{\mathrm{M}}_{\mathrm{host}}$ variation

    Ji-Guo Zhang🇺🇸 · Yichao Li🇺🇸 · Jia-Ming Zou · Ze-Wei Zhao🇺🇸 · Jing-Fei Zhang🇺🇸 · Xin Zhang🇺🇸

    Fast radio bursts (FRBs) have been found in great numbers, but the physical mechanism of these sources is still a mystery. The redshift evolutions of the FRB energy distribution function and the volumetric rate shed light on the origin of FRBs. However, such estimations rely on the dispersion measurement (DM)-redshift ($z$) relationship. A few FRBs that have been detected recently show large excess DMs beyond the expectation from the cosmological and Milky Way contributions, which indicates large spread of DMs from their host galaxies. In this work, we adopt two lognormal-distributed ${\mathrm{DM}}_{\mathrm{host}}$ models and estimate the energy function using the non-repeating FRBs selected from the Canadian Hydrogen Intensity Mapping Experiment (CHIME)/FRB Catalog 1. By comparing the lognormal-distributed ${\mathrm{DM}}_{\mathrm{host}}$ models to a constant ${\mathrm{DM}}_{\mathrm{host}}$ model, the FRB energy function results are consistent within the measurement uncertainty. We also estimate the volumetric rate of the non-repeating FRBs in three different redshift bins. The volumetric rate shows that the trend is consistent with the stellar-mass density redshift evolution. Since the lognormal-distributed ${\mathrm{DM}}_{\mathrm{host}}$ model increases the measurement errors, the inference of FRBs tracking the stellar-mass density is nonetheless undermined.

    ↳ astro-ph.HEastro-ph.COgr-qchep-phUniverse(2024)·15 citations
22. 22*

    Dynamically screened strongly quantized electron transport in binary neutron-star merger

    Sreemoyee Sarkar🇮🇳 · Souvik Priyam Adhya🇵🇱

    We examine electron-transport coefficients in magnetized hot and dense electron-ion plasma relevant in binary neutron star merger simulation. We calculate electrical and thermal conductivities in low density, high temperature, highly magnetized plasma of binary neutron star mergers where quantum oscillatory behavior of electrons emerge. For pronounced thermodynamic effects, we consider zeroth Landau level population of electrons for the calculation of conductivity. We solve Boltzmann equation in presence of magnetic field to obtain the dissipative components of electrical and thermal conductivities. The dissipative coefficients are formulated considering frequency dependent dynamical screening in the quantized electron-ion scattering rate. Numerical estimations show that the effect of dynamical screening of photon propagator on electrical and thermal conductivities is pronounced. We observe that dynamical screening reduces the maxima of both the electrical and thermal conductivities by factors of thirty one and twenty respectively leading to a reduction in the corresponding time scales of these coefficients. The common scaling factor between electrical and thermal conductivity is also observed to follow cubic relationship with temperature violating Wiedemann-Franz law.

    ↳ nucl-thastro-ph.HEhep-phEPJC(2023)·4 citations
23. 23*

    New insights on $\nu$-DM Interactions

    Philippe Brax🇫🇷 · Carsten van de Bruck🇬🇧 · Eleonora Di Valentino🇬🇧 · William Giarè🇬🇧 · Sebastian Trojanowski🇵🇱

    We revisit the possibility of using cosmological observations to constrain models that involve interactions between neutrinos and dark matter. We show that small-scale measurements of the cosmic microwave background with a few per cent accuracy are critical to uncover unique signatures from models with tiny couplings that would require a much higher sensitivity at lower multipoles, such as those probed by the Planck satellite. We analyze the high-multipole data released by the Atacama Cosmology Telescope, both independently and in combination with Planck and Baryon Acoustic Oscillation measurements, finding a compelling preference for a non-vanishing coupling, ${\log }_{10}{u}_{\nu \text{DM}}=-5.20_{-0.74}^{+1.2}$ at 68% CL. This aligns with other CMB-independent probes, such as Lyman-$\alpha$. We illustrate how this coupling could be accounted for in the presence of dark matter interactions with a sterile neutrino.

    ↳ astro-ph.COhep-phMNRAS(2023)·16 citations
24. 24*

    Mixed Graviton and Scalar Bispectra in the EFT of Inflation: Soft Limits and Boostless Bootstrap

    Diptimoy Ghosh🇮🇳 · Kushan Panchal🇮🇳 · Farman Ullah🇮🇳

    Boostless Bootstrap techniques have been applied by many in the literature to compute pure scalar and graviton correlators. In this paper, we focus primarily on mixed graviton and scalar correlators. We start by developing an EFT of Inflation (EFToI) with some general assumptions, clarifying various subtleties related to power counting. We verify explicitly the soft limits for mixed correlators, showing how they are satisfied for higher derivative operators beyond the Maldacena action. We clarify some confusion in the literature related to the soft limits for operators that modify the power spectra of gravitons or scalars. We then proceed to apply the boostless bootstrap rules to operators that do not modify the power spectra. Towards the end, we give a prescription that gives correlators for states that are Bogolyubov transforms of the Bunch-Davies vacuum, directly once we have the correlator for the Bunch-Davies vacuum. This enables us to bypass complicated in-in calculations for Bogolyubov states.

    ↳ hep-thgr-qchep-phJHEP(2023)·18 citations
25. 25*

    Constraining the dark matter contribution of $\gamma$ rays in Cluster of galaxies using Fermi-LAT data

    Mattia Di Mauro🇮🇹 · Judit Pérez-Romero🇪🇸 · Miguel A. Sánchez-Conde🇪🇸 · Nicolao Fornengo🇮🇹

    Clusters of galaxies are the largest gravitationally-bound systems in the Universe. Their dynamics are dominated by dark matter (DM), which makes them among the best targets for indirect DM searches. We analyze 12 years of data collected by the Fermi Large Area Telescope (Fermi-LAT) in the direction of 49 clusters of galaxies selected for their proximity to the Earth and their high X-ray flux, which makes them the most promising targets. We first create physically motivated models for the DM density around each cluster considering different assumptions for the substructure distribution. Then we perform a combined search for a $\gamma$-ray signal in the {\it Fermi}-LAT data between 500 MeV and 1 TeV. We find a signal of $\gamma$ rays potentially associated with DM that is at a statistical significance of $2.5\sigma -3.0\sigma$ when considering a slope for the subhalo mass distribution $\alpha =1.9$ and minimum mass of $M_{\min }=10^{-6}$ $M_{\odot }$. The best-fit DM mass and annihilation cross-sections for a $b\bar{b}$ annihilation channel are $m_{\chi }=40-60$ GeV and $⟨\sigma v⟩=(2-4)\times 10^{-25}$ cm${}^3$/s. When we consider $\alpha =2.0$ and $M_{\min }=10^{-9}$ $M_{\odot }$, the best-fit of the cross section reduces to $⟨\sigma v⟩=(4-10)\times 10^{-26}$ cm${}^3$/s. For both DM substructure models there is a tension between the values of $⟨\sigma v⟩$ that we find and the upper limits obtained with the non-detection of a $\gamma$-ray flux from Milky Way dwarf spheroidal galaxies. This signal is thus more likely associated with $\gamma$ rays produced in the intracluster region by cosmic rays colliding with gas and photon fields.

    ↳ astro-ph.HEastro-ph.COhep-phPRD(2023)·36 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.