Fri·Oct 15, 2021Friday·October 15, 2021

1. 01*

   Electroweak Symmetry Breaking and WIMP-FIMP Dark Matter

   Subhaditya Bhattacharya🇮🇳 · Sreemanti Chakraborti🇫🇷 · Dipankar Pradhan🇮🇳

   Electroweak Symmetry Breaking (EWSB) is known to produce a massive universe that we live in. However, it may also provide an important boundary for freeze-in or freeze-out of dark matter (DM) connected to Standard Model via Higgs portal as processes contributing to DM relic differ across the boundary. We explore such possibilities in a two-component DM framework, where a massive $U(1{)}_X$ gauge boson DM freezes-in and a scalar singlet DM freezes-out, that inherits the effect of EWSB for both the cases in a correlated way. Amongst different possibilities, we study two sample cases; first when one DM component freezes in and the other freezes out from thermal bath both necessarily $before$ EWSB and the second, when both freeze-in and freeze-out occur $after$ EWSB. We find some prominent distinctive features in the available parameter space of the model for these two cases, after addressing relic density and the recent most direct search constraints from XENON1T, some of which can be borrowed in a model independent way.

   hep-phJHEP(2022)·19 citations
2. 02*

   Pion and Kaon Distribution Amplitudes up to twist-3 in the QCD Instanton Vacuum

   Arthur Kock🇺🇸 · Ismail Zahed🇺🇸

   We discuss the pion and kaon distribution amplitudes up to twist-3 in the context of the random instanton vacuum (RIV). We construct explicitly the pertinent quasi-pion and quasi-kaon distributions in the RIV, and analyze them in leading order in the diluteness factor, at a resolution fixed by the inverse instanton size. The distribution amplitudes (DA) follow from the large momentum limit. The results at higher resolution are discussed using QCD evolution, and compared to their asymptotic limits and some lattice results.

   hep-phPRD(2021)·11 citations
3. 03*

   Structure of Stellar Remnants with Coupling to a Light Scalar

   Christina Gao🇺🇸 · Albert Stebbins🇺🇸

   In this paper we study how a Yukawa coupling of the Standard Model fermions to a light scalar field effects the stellar structure of cold stellar remnants such as neutron stars. We elucidate the stellar structure phenomenology using a simple model of a massive scalar coupled to a single dominant fermion with no other interactions. For a broad scalar mass range ($10^{-10}\mathrm{eV}\ll m_{\varphi }\ll 10^3\mathrm{eV}$ for neutron stars) we show that the equation-of-state and stellar structure depends only the effective coupling $\mathfrak{g}=\frac{g_f{m}_f}{m_{\varphi }}$, where $g_f$ is the Yukawa coupling, $m_f$ the fermion mass and $m_{\varphi }$ is the scalar kinematic mass at nuclear densities. If $\mathfrak{g}>\mathcal{O}(1)$ the Yukawa coupled matter exhibits various anomalous behaviors including hydrodynamic instability, negative pressure, distinct phases (soft and hard) of matter with sharp phase boundaries between them and with vacuum. These anomalies can lead to stars consisting of only soft, only hard or hybrid of soft and hard matter. These stars can have varying signs of the slope of the mass-radius relation, anomalously large and small masses, gaps in allowed radii, multiple radii for the same mass, very thin crusts and radiate anomalously large amounts of energy when they form (in the form of neutrinos for neutron stars). To the extent that these anomalies have not and/or will not be observed limits the effective coupling to $\mathfrak{g}<\mathcal{O}(1)$. We argue this phenomenology is generic to realistic models of stars with Yukawa coupled matter.

   hep-phJCAP(2022)·11 citations
4. 04*

   Spectral representation of neutrino propagator in media and off-shell spin properties

   A.E.Kaloshin🇷🇺 · D.M.Voronin🇷🇺

   We construct a spectral representation of neutrino propagator in matter moving with constant velocity, or in constant homogenious magnetic field. In both cases there exists definite 4-axis $z$ of complete polarization, such that corresponding spin projectos commute with propagator. As a result, all eigenvalues of propagator and dispersion laws are classified accoding to spin projection on this axis.

   hep-ph0 citations
5. 05*

   Smooth interpolation between thermal Born and LPM rates

   J. Ghiglieri🇫🇷 · M. Laine🇨🇭

   In a weakly coupled ultrarelativistic plasma, $1+n\leftrightarrow 2+n$ scatterings, with $n\ge 0$, need sometimes to be summed to all orders, in order to determine a leading-order interaction rate. To implement this "LPM resummation", kinematic approximations are invoked. However, in cosmological settings, where the temperature changes by many orders of magnitude and both small and large momenta may play a role, such approximations are not always justified. We suggest a procedure to smoothly interpolate between LPM-resummed $1+n\leftrightarrow 2+n$ and Born-level $1\leftrightarrow 2$ results, rendering the outcome applicable to a broader range of masses and momenta. The procedure is illustrated for right-handed neutrino production from a Standard Model plasma, and dilepton production from a QCD plasma.

   hep-phJHEP(2022)·15 citations
6. 06*

   Simple BSM explanations of $a_{\mu }$ in light of the FNAL muon $g-2$ measurement

   Peter Athron🇨🇳 · Csaba Balázs🇦🇺 · Douglas Jacob🇦🇺 · Wojciech Kotlarski🇩🇪 · Dominik Stöckinger🇩🇪 · Hyejung Stöckinger-Kim🇩🇪

   Now that the Fermilab muon $g-2$ experiment has released the results of its Run-1 data, which agrees with the results of the Brookhaven experiment, one can examine the potential of simple extensions to explain the combined $4.2\sigma$ discrepancy between the SM prediction and experiment. This proceeding examines a single-, two-, and three-field extension of the standard model and examines their ability to explain the muon $g-2$ anomaly, and where possible, produce a dark matter candidate particle with the observed relic density. This is based on work carried out for Ref. [1]. It is found that one can only explain the $a_{\mu }$ discrepancy whilst avoiding dark matter and collider constraints when the contributions from BSM fields benefit from a chirality flip enhancement. However, in general without small couplings and/or large masses, these models can be heavily constrained by collider and dark matter experiments.

   hep-phPoS(2022)·3 citations
7. 07*

   Dilepton production rate near the critical temperature of color superconductivity

   Toru Nishimura🇯🇵 · Masakiyo Kitazawa🇯🇵 · Teiji Kunihiro🇯🇵

   We investigate modification of the dilepton production rate by the diquark fluctuations that form well-developed collective modes near the critical temperature of color superconductivity. Through the analysis of the photon self-energy called the Aslamasov-Larkin, Maki-Thompson and density of states terms in the theory of metalic superconductivity, it is shown that the collective mode in the diquark channel affects the photon self-energy significantly and thereby gives rise to an anomalous enhacement of the dilepton production rate in the low invariant-mass region.

   hep-phPoS(2022)·0 citations
8. 08*

   A dark matter solution for the XENON1T electron excess and the galactic center 511 keV line

   Yasaman Farzan🇮🇷

   The excess of the 511 keV line from the Milky Way galactic bulge, confirmed by the INTEGRAL detector, is a longstanding mystery. The morphology of the line appears to be proportional to the square of the dark matter density, hinting towards a dark matter origin. On the other hand, in 2020, XENON1T has reported an excess of electrons with a recoil energy of $2-4$ keV. We present a model based on a dark matter of a few MeV mass that decays into a pair of pico-charged particles with a lifetime much larger than the age of the Universe. The magnetic field of the galaxy accumulates these relativistic pico-charged particles whose scattering on the electrons can explain the signal reported by XENON1T. The annihilation of the pico-charged particles in the galactic bulge leads to $e^{-}{e}^{+}$ production and therefore to an excess of the 511 keV line. We review the present observational bounds and the strategies to test the model.

   hep-ph1 citation
9. 09*

   Hide-and-seek with cosmic tau neutrinos

   Yasaman Farzan🇮🇷

   We first revisit the possibility of preserving the original flavor ratio of high energy cosmic neutrino flux by turning on a coupling between these neutrinos and ultra-light dark matter. We discuss the bound that can be set on such a coupling from the recent ${\nu }_{\tau }$ observation by ICECUBE and outline the implications of the coupling for the EeV range cosmic neutrino flux to be observed by upcoming neutrino detectors. We then focus on the $3+1$ scheme when the active sterile oscillation length is of order of 1000~km for EeV range cosmic neutrinos. We show that within this scenario, the probability of survival of an active neutrino passing through the Earth can be sizable, despite the fact that the mean free path of the EeV neutrinos is much smaller than the Earth radius. This opens up the possibility to have neutrino events similar to the two anomalous events reported by ANITA.

   hep-phastro-ph.HEPoS(2022)·2 citations
10. 10*

    Probing a Finite Unified Theory with Reduced Couplings at Future Colliders

    S.Heinemeyer🇪🇸 · J. Kalinowski🇵🇱 · W. Kotlarski🇩🇪 · M. Mondragón🇲🇽 · G. Patellis🇬🇷 · N. Tracas🇩🇪 · G. Zoupanos🇬🇷

    The search for relations among parameters that are renormalization group invariant to all orders in perturbation theory constitutes the basis of the reduction of couplings idea. Reduction of couplings can be achieved in $N=1$ Grand Unified Theories, few of which can become even all-loop finite. We review the basic idea and a resulting theory in which successful reduction of couplings has been achieved, namely the all-loop finite $N=1$ supersymmetric $SU(5)$ model. We present three benchmark scenarios and investigate their observability at existing and future hadron colliders. The supersymmetric spectrum is found to be beyond the reach of the 14 TeV HL-LHC. In turn, it is found that large parts of the predicted spectrum can be tested at the 100 TeV FCC-hh, but the higher mass regions remain out of reach.

    hep-phPoS(2022)·2 citations
11. 11*

    The IDM and THDMa -- current constraints and future prospects

    Tania Robens🇭🇷

    We discuss two models that extend the Standard Model by additional particles, leading to additional scalar states, and also providing dark matter candidates. We briefly review the current constraints and comment on production cross sections at present and future collider facilities.

    hep-phPoS(2022)·4 citations
12. 12*

    Bloch-Nordsieck restoration in llbar -> qqbar

    Franziska Reiner🇦🇹 · Axel Maas🇦🇹

    Usually, the Bloch-Nordsieck theorem is expected to be violated in weak interactions, as the corresponding asymptotic states are not weak singlets. However, a manifest gauge-invariant approach replaces the asymptotic states with composite states, and thereby restores the Bloch- Nordsieck theorem. The Froehlich-Morchio-Strocchi mechanism ensures that this is in agreement with existing phenomenology. We outline the necessary steps of this construction.

    hep-phPoS(2022)·4 citations
13. 13*

    The $Z_{cs}(3985)$ structure, if a triangle/kinematic singularity, would disappear when heated in Heavy Ion Collisons

    Felipe J. Llanes-Estrada🇪🇸 · Luciano M. Abreu🇧🇷

    Triangle and other kinematic singularities are very sensitive to the precise masses and widths of the intervening particles. Therefore, the effect that the heavy-ion collision medium can have on those masses and widths, as captured by finite-temperature field theory and reported in the literature, may erase the singularity from the spectrum if the effect is large enough and the loop completes before the hot gas freezes out. A very timely example is provided by the $Z_{cs}(3985)$ structure recently reported by BES-III in a $(D_s^{-}{D}^{\ast 0}+D_s^{\ast -}{D}^0)$ spectrum recoiling against a $K^{+}$. If a new hadron, this would be a clear exotic $c\bar{c}s\bar{u}$ tetraquark candidate, the first of a charmonium-like family with strangeness: to accept this, alternative explanations first need to be tested and discarded. As shown in figure 1, the mass spectrum recoiling against the kaon is near the $m_{D_s^{\ast -}}+m_{D^0}$ threshold, whereas the production cross-section seems to peak around that for $\sqrt{s(e^{-}{e}^{+})}=m_{D_{s2}^{\ast +}}+m_{D_s^{\ast -}}$. Therefore, this structure may well be caused by a triangle with the three charmed mesons $D_{s2}^{\ast +}/D_s^{\ast -}/D^0$ running in the loop, with the amplitude enhanced at the two thresholds. If so, the structure would be erased from the spectrum in Heavy Ion Collisions, whereas a hadron would continue to exist although with a mass decreased by a few percent as computed by other authors.

    hep-phnucl-thPoS(2022)·5 citations
14. 14*

    NLO electroweak and QCD corrections to off-shell ttW production at the LHC

    Ansgar Denner🇩🇪 · Giovanni Pelliccioli🇩🇪

    The foreseen luminosities for the next LHC runs will enable precise differential measurements of the associated production of top-antitop pairs with a W boson. Therefore, providing accurate theory predictions for this process is needed for realistic final states. We present the first combination of NLO electroweak and QCD corrections to off-shell ttW${}^{+}$ production in the three-charged-lepton channel, including non-resonant effects, full spin-correlations and interferences. Such radiative corrections comprise the electroweak and QCD corrections to the leading QCD order, and the QCD corrections to the leading electroweak order.

    hep-phhep-exSciPost Phys.Proc.(2022)·2 citations
15. 15*

    Addressing the Muon Anomalies With Muon-Flavored Leptoquarks

    Admir Greljo🇨🇭 · Peter Stangl🇨🇭 · Anders Eller Thomsen🇨🇭

    Significant deviations from Standard Model (SM) predictions have been observed in $b\to s{\mu }^{+}{\mu }^{-}$ decays and in the muon $g-2$. Scalar leptoquark extensions of the SM are known to be able to address these anomalies, but generically give rise to lepton flavor violation (LFV) or even proton decay. We propose new muon flavored gauge symmetries as a guiding principle for leptoquark models that preserve the global symmetries of the SM and explain the non-observation of LFV. A minimal model is shown to easily accommodate the anomalies without encountering other experimental constraints. This talk is mainly based on Ref. [1].

    hep-phPoS(2022)·0 citations
16. 16*

    Holographic QCD and the muon anomalous magnetic moment

    Josef Leutgeb🇦🇹 · Jonas Mager🇦🇹 · Anton Rebhan🇦🇹

    We review the recent progress made in using holographic QCD to study hadronic contributions to the anomalous magnetic moment of the muon, in particular the hadronic light-by-light scattering contribution, where the short-distance constraints associated with the axial anomaly are notoriously difficult to satisfy in hadronic models. This requires the summation of an infinite tower of axial vector mesons, which is naturally present in holographic QCD models, and indeed takes care of the longitudinal short-distance constraint due to Melnikov and Vainshtein. Numerically the results of simple hard-wall holographic QCD models point to larger contributions from axial vector mesons than assumed previously, while the predicted contributions from pseudo-Goldstone bosons agree nicely with data-driven approaches.

    hep-phhep-thEPJC(2021)·20 citations
17. 17*

    Effective range expansion for narrow near-threshold resonances

    Vadim Baru🇩🇪 · Xiang-Kun Dong🇨🇳 · Meng-Lin Du🇪🇸 · Arseniy Filin🇩🇪 · Feng-Kun Guo🇨🇳 · Christoph Hanhart🇩🇪 · Alexey Nefediev🇷🇺 · Juan Nieves🇪🇸 · Qian Wang🇨🇳

    We discuss some general features of the effective range expansion, the content of its parameters with respect to the nature of the pertinent near-threshold states and the necessary modifications in the presence of coupled channels, isospin violations and unstable constituents. As illustrative examples, we analyse the properties of the ${\chi }_{c1}(3872)$ and $T_{cc}^{+}$ states supporting the claim that these exotic states have a predominantly molecular nature.

    hep-phhep-exhep-latnucl-thPLB(2022)·91 citations
18. 18*

    Ultra-high-energy neutrino scattering in an anomalous U(1) effective field theory

    Chuan-Hung Chen🇹🇼 · Cheng-Wei Chiang🇹🇼 · Chun-Wei Su🇹🇼

    A unique characteristic of exponentially growing scattering amplitude arises in an anomalous Abelian effective field theory when an extremely light Dirac neutrino mass is introduced to break the symmetry. We show that the low energy effective Lagrangian can be made explicitly gauge invariant with the help of a nonlinear representation of the Goldstone or Stueckelberg field. We study the peculiar feature of exponential growth in the ultra-high-energy neutrino-nucleon inelastic scattering. It is found that the inelastic scattering cross section is highly sensitive to the ratio of gauge coupling to the gauge boson mass, $g_X/m_X$. When the IceCube measurement of ultra-high-energy neutrinos, which is consistent with the standard model prediction up to $E_{\nu }\sim 6$ PeV, is taken into account, the inferred constraint on $g_X/m_X$ is more severe than that obtained from the events of mono-lepton$+$missing transverse energy at the LHC. A muon collider with a collision energy of $10$ TeV can be a good environment other than hadron colliders to probe the novel effect.

    hep-phastro-ph.HEhep-exPLB(2022)·2 citations
19. 19*

    $J/\psi$ polarization in semi-inclusive DIS at low and high transverse momentum

    Umberto D'Alesio🇮🇹 · Luca Maxia🇮🇹 · Francesco Murgia🇮🇹 · Cristian Pisano🇮🇹 · Sangem Rajesh🇮🇹

    We study the polar and azimuthal decay angular distributions of $J/\psi$ mesons produced in semi-inclusive, deep-inelastic electron-proton scattering. For the description of the quarkonium formation mechanism, we adopt the framework of nonrelativistic QCD, with the inclusion of the intermediate color-octet channels that are suppressed at most by a factor $v^4$ in the velocity parameter $v$ relative to the leading color-singlet channel. We put forward factorized expressions for the helicity structure functions in terms of transverse momentum dependent gluon distributions and shape functions, which are valid when the $J/\psi$ transverse momentum is small with respect to the hard scale of the process. By requiring that such expressions correctly match with the collinear factorization results at high transverse momentum, we determine the perturbative tails of the shape functions and find them to be independent of the $J/\psi$ polarization. In particular, we focus on the $\cos 2\varphi$ azimuthal decay asymmetry, which originates from the distribution of linearly polarized gluons inside an unpolarized proton. We therefore suggest a novel experiment for the extraction of this so-far unknown parton density that could be performed, in principle, at the future Electron-Ion Collider.

    hep-phJHEP(2022)·25 citations
20. 20*

    Leading-Color Two-Loop Amplitudes for Four Partons and a W Boson in QCD

    S. Abreu🇨🇭 · F. Febres Cordero🇺🇸 · H. Ita🇩🇪 · M. Klinkert🇩🇪 · B. Page🇨🇭 · V. Sotnikov🇩🇪

    We present the leading-color two-loop QCD corrections for the scattering of four partons and a $W$ boson, including its leptonic decay. The amplitudes are assembled from the planar two-loop helicity amplitudes for four partons and a vector boson decaying to a lepton pair, which are also used to determine the planar two-loop amplitudes for four partons and a $Z/{\gamma }^{\ast }$ boson with a leptonic decay. The analytic expressions are obtained by setting up a dedicated Ansatz and constraining the free parameters from numerical samples obtained within the framework of numerical unitarity. The large linear systems that must be solved to determine the analytic expressions are constructed to be in Vandermonde form. Such systems can be very efficiently solved, bypassing the bottleneck of Gaussian elimination. Our results are expressed in a basis of one-mass pentagon functions, which opens the possibility of their efficient numerical evaluation.

    hep-phJHEP(2022)·93 citations
21. 21*

    Enhancement of charm CP violation due to nearby resonances

    Stefan Schacht🇬🇧 · Amarjit Soni🇺🇸

    Quantitative understanding of CP violation is extremely important as naturalness reasoning strongly suggests that new physics should be accompanied by beyond the Standard Model CP-odd phases. In 2019 LHCb made the first $5\sigma$ discovery of CP violation in the charm system, leading to the new world average $\Delta a_{CP}^{\mathrm{dir}}=-0.00161\pm 0.00028$. While some calculations have found this observation as requiring new physics, we suggest that scalar resonances nearby to $m_{D^0}$, in particular, $f_0(1710)$ and/or $f_0(1790)$ cause enhancements for CP violation within the SM. Thereby, our calculations based on the Standard Model suggest compatibility with the LHCb observations for now. However, experimental information especially on $f_0(1790)$ is rather sparse limiting our accuracy and further data on these resonances is strongly advocated.

    hep-phhep-exPLB(2022)·50 citations
22. 22*

    $Z$ mediated Flavour Changing Neutral Currents with a Fourth Vector-Like Family

    A. E. Cárcamo Hernández🇨🇱 · S. F. King🇬🇧 · H. Lee🇬🇧

    We discuss $Z$ mediated flavour changing neutral currents within a model where the hierarchical quark and lepton masses are explained via a fourth vector-like family, together with a scalar sector consisting of two Higgs doublets augmented by a gauge singlet scalar field that spontaneously breaks an extra global $U(1{)}^{\prime }$ symmetry. The $Z$ mediated flavor violating interactions arise from the mixings between the SM fermions and the vector-like fermions, where the mixing is discussed in an analytic approximation and also exactly numerically. We first discuss charged lepton flavor violating (CLFV) $\tau \to \mu \gamma ,\tau \to 3\mu$ and $Z\to \mu \tau$ decays and find that they cannot significantly constrain the masses of charged vector-like leptons. However, the $790\text{GeV}$ mass bound arising from collider searches on vector-like lepton doublets can set further constraints on the model parameter space. We also consider rare $t\to cZ$ decays as well as unitarity violation in the CKM mixing in order to constrain the quark sector of the model under consideration.

    hep-phPRD(2022)·12 citations
23. 23*

    Cosmological evolution in Weyl conformal geometry

    D. M. Ghilencea🇷🇴 · T. Harko🇷🇴

    We discuss the cosmological evolution of the Weyl conformal geometry and its associated Weyl quadratic gravity. The Einstein gravity (with a positive cosmological constant) is recovered in the spontaneously broken phase of Weyl gravity; this happens after the Weyl gauge field (${\omega }_{\mu }$) of scale symmetry, that is part of the Weyl geometry, becomes massive by Stueckelberg mechanism and then decouples. This breaking is a natural result of the cosmological evolution of Weyl geometry, in the absence of matter. Of particular interest in the analysis is the special limiting case of Weyl integrable geometry. Both this case and the general one provide an accelerated expansion of the Universe, controlled by the scalar mode of the ${\tilde{R}}^2$ term in the action and by ${\omega }_0$. Their comparison to the $\Lambda$CDM model shows a very good agreement to this model for the (dimensionless) Hubble function $h(z)$ and the deceleration $q(z)$ for redshift $z\le 3$. Therefore, the Weyl conformal geometry and its associated Weyl quadratic gravity provide an interesting alternative to the $\Lambda$CDM model and to the Einstein gravity.

    ↳ gr-qcastro-ph.COhep-phhep-th21 citations
24. 24*

    Muon to positron conversion

    MyeongJae Lee🇰🇷 · Michael MacKenzie🇺🇸

    Lepton flavor violation (LFV) has been discovered in the neutrino sector by neutrino oscillation experiments. The minimally extended Standard Model (SM) to include neutrino masses allows LFV in the charged sector (CLFV) at the loop-level, but at rates that are too small to be experimentally observed. Lepton number violation (LNV) is explicitly forbidden even in the minimally extended SM, where the observation of a LNV process would be unambiguous evidence of physics beyond the SM. The search for the LNV and CLFV process ${\mu }^{-}+N(A,Z)\to e^{+}+N^{\prime }(A,Z-2)$ (referred to as ${\mu }^{-}\to e^{+}$ conversion) is a complementary LNV channel to neutrinoless double beta decay searches, sensitive to potential flavor effects in the neutrino mass generation mechanism. A theoretical motivation for ${\mu }^{-}\to e^{+}$ conversion is presented along with a review of the status of past ${\mu }^{-}\to e^{+}$ conversion experiments and future prospects. Special attention is taken to understanding an uncertain and potentially dominant background for these searches, radiative muon capture, and its potential impacts on current and future ${\mu }^{-}\to e^{+}$ searches.

    ↳ hep-exhep-phUniverse(2022)·17 citations
25. 25*

    Noether charges: the link between empirical significance of symmetries and non-separability

    Henrique Gomes🇬🇧

    A fundamental tenet of gauge theory is that physical quantities should be gauge-invariant. This prompts the question: can gauge symmetries have physical significance? On one hand, the Noether theorems relate conserved charges to symmetries, endowing the latter with physical significance, though this significance is sometimes taken as indirect. But for theories in spatially finite and bounded regions, the standard Noether charges are not gauge-invariant. I here argue that gauge-\emph{variance} of charges is tied to the nature of the non-locality within gauge theories. I will flesh out these links by providing a chain of (local) implications: `local conservation laws'$\Rightarrow$ `conserved regional charges' $\iff$ `non-separability' $\iff$ `direct empirical significance of symmetries'.

    ↳ physics.hist-phhep-phhep-thPublished in: The Physics and Philosophy …·1 citation
26. 26*

    Supernova Preshock Neutronization Burst as a Probe of Non-Standard Neutrino Interactions

    Xu-Run Huang🇨🇳 · Shuai Zha🇨🇳 · Lie-Wen Chen🇨🇳

    Core-collapse supernova (CCSN) provides a unique astrophysical site for studying neutrino-matter interactions. Prior to the shock-breakout neutrino burst during the collapse of the iron core, a preshock ${\nu }_e$ burst arises from the electron capture of nuclei and it is sensitive to the low-energy coherent elastic neutrino-nucleus scattering (CE$\nu$NS) which dominates the neutrino opacity. Since the CE$\nu$NS depends strongly on the non-standard neutrino interactions (NSI) which are completely beyond the standard model and yet to be determined, the detection of the preshock burst thus provides a clean way to extract the NSI information. Within the spherically symmetric general-relativistic hydrodynamic simulation for the CCSN, we investigate the NSI effects on the preshock burst. We find that the NSI can maximally enhance the peak luminosity of the preshock burst almost by a factor of three, reaching a value comparable with that of the shock-breakout burst. Future detection of the preshock burst will have critical implications on astrophysics, neutrino physics and physics beyond the standard model.

    ↳ astro-ph.HEhep-phnucl-exnucl-thApJL(2021)·6 citations
27. 27*

    Comments on the Transplanckian Censorship Conjecture

    Michael Dine🇺🇸 · Yan Yu🇺🇸

    We consider some aspects of the Transplanckian Censorship Conjecture, which states that for theories of quantum gravity which yield a quintessence universe, there is a limit on the lifetime of the state not too different than the current Hubble horizon. We consider some aspects of tunneling in the presence of time-varying fields, and note that lifetimes can be parameterically quite large. We consider what it might mean to find a quintessence potential in string theory, and argue that such states are likely to have very long lifetimes.

    ↳ hep-thhep-phJHEP(2023)·3 citations
28. 28*

    Progress in $x$-dependent partonic distributions from lattice QCD

    Krzysztof Cichy🇵🇱

    We review the latest progress in lattice QCD calculations of the partonic structure of hadrons. This structure is, in particular, described in terms of $x$-dependent distributions, the simplest of which are the standard parton distribution functions (PDFs). The lattice calculations rely on matrix elements probing spatial correlations between partons in a boosted hadron, that can be matched to light-cone correlations defining the relevant distributions. We discuss the recent theoretical and practical refinements of this strategy, as well as new exploratory directions. The latter include generalized parton distributions (GPDs), distributions beyond leading twist, flavor-singlet distributions and transverse-momentum dependent PDFs (TMDs). We also shortly consider the potential future impact of lattice data on phenomenology.

    ↳ hep-lathep-phPoS(2022)·60 citations
29. 29*

    BD-$\Lambda$CDM and Running Vacuum Models: Theoretical background and current observational status

    Javier de Cruz Perez🇺🇸 · Joan Sola Peracaula🇪🇸 · Adria Gomez-Valent🇪🇸 · Cristian Moreno-Pulido

    We present an analysis of the Brans-Dicke cosmological model with a cosmological constant and cold dark matter (BD-$\Lambda$CDM). We find that the BD-$\Lambda$CDM is favored by the overall cosmological data (SNIa+BAO+$H(z)$+LSS+CMB) when it is compared with the standard model of cosmology. The BD-$\Lambda$CDM model can be viewed from the GR perspective as a Running Vacuum Model (RVM) with a time evolving vacuum energy density. Due to this fact and also to its time evolving effective gravitational coupling, the model can alleviate the ${\sigma }_8$ and the $H_0$ tensions at a time. We also present the results for different types of RVM's when they are tested in the light of the cosmological data and we show that a mild dynamics for the vacuum energy density can help to smooth out the aforementioned tensions, thus improving the performance of $\Lambda$CDM model.

    ↳ astro-ph.COgr-qchep-phhep-th15 citations
30. 30*

    The Gravity of Classical Fields: And Its Effect on the Dynamics of Gravitational Systems

    Rodrigo Vicente🇵🇹

    Classical fields are ubiquitous in theoretical physics. They find applications in almost all areas of physics, from condensed matter and particle physics to cosmology and astrophysics. Scalar fields, in particular, can give rise to confined structures, such as boson stars, oscillatons or Q-balls. These objects are interesting hypothetical new "dark matter stars", but also good descriptions of dark matter cores when the fields are ultralight. In this thesis, we study the dynamical response of such confined bosonic structures when excited by external matter (stars, planets or black holes) in their vicinities. Such perturbers can either be piercing through the bosonic configuration or undergoing periodic motion at its center (e.g., binaries). Our setup can also efficiently describe the interaction between a moving massive black hole and the surrounding environment. It also depicts dark matter depletion as a reaction to an inspiralling binary within a dark matter core. Our results provide a complete picture of the interaction between black holes or stars and the ultralight dark matter core environment where they may live in. This thesis also deals with several classical field environmental effects on the motion (or, ultimately, the survival) of compact objects, like black holes.

    ↳ gr-qcastro-ph.GAastro-ph.HEhep-ph0 citations
31. 31*

    Hydrodynamic Gradient Expansion Diverges beyond Bjorken Flow

    Michal P. Heller🇩🇪 · Alexandre Serantes🇵🇱 · Michał Spaliński🇵🇱 · Viktor Svensson🇩🇪 · Benjamin Withers🇬🇧

    The gradient expansion is the fundamental organising principle underlying relativistic hydrodynamics, yet understanding its convergence properties for general nonlinear flows has posed a major challenge. We introduce a simple method to address this question in a class of fluids modelled by Israel-Stewart--type relaxation equations. We apply it to (1+1)-dimensional flows and provide numerical evidence for factorially divergent gradient expansions. This generalises results previously only obtained for (0+1)-dimensional comoving flows, notably Bjorken flow. We also demonstrate that the only known nontrivial case of a convergent hydrodynamic gradient expansion at the nonlinear level relies on Bjorken flow symmetries and becomes factorially divergent as soon as these are relaxed. Finally, we show that factorial divergence can be removed using a momentum space cutoff, which generalises a result obtained earlier in the context of linear response.

    ↳ hep-thhep-phnucl-thphysics.flu-dynPRL(2022)·27 citations
32. 32*

    Logarithmic Extensions to Inflation Universality Classes

    Eric V. Linder🇺🇸

    The values of, and connection between, the cosmological observables of the primordial power spectrum tilt $n_s$ and the inflationary tensor to scalar ratio $r$ are key guideposts to the physics of inflation. Universality classes can be defined for the tilt from the scale free value proportional to $1/N$, where $N$ is the number of e-folds. We examine the consequences of a $\ln N$ next to leading order correction rather than an expansion in $1/N$, or introducing a new parameter. While nominally this can lower $r$ for some too-high $r$ simple inflation models (e.g. large field models), there is an interesting cancellation preventing such models from coming back into favor. On the other branch of the universality class, near Starobinsky inflation, $r$ can be raised, making it easier to detect.

    ↳ astro-ph.COhep-phhep-th1 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.