Fri·Sep 2, 2022Friday·September 2, 2022

1. 01*

   Prospects for heavy neutral SUSY Higgs scalars in the hMSSM and natural SUSY at LHC upgrades

   Howard Baer🇺🇸 · Vernon Barger🇺🇸 · Xerxes Tata🇺🇸 · Kairui Zhang🇺🇸

   We examine production and decay of heavy neutral SUSY Higgs bosons pp-> H,\ A -> \tau\bar{\tau} within the hMSSM and compare against a perhaps more plausible natural supersymmetry scenario dubbed m_h^{125}({\rm nat}) which allows for a natural explanation for m_{weak}\simeq m_{W,Z,h}\sim 100 GeV while maintaining m_h\simeq 125 GeV. We evaluate signal against various Standard Model backgrounds from \gamma ,Z ->\tau\bar{\tau}, t\bar{t} and vector boson pair production VV. We combine the transverse mass method for back-to-back (BtB) taus along with the ditau mass peak m_{\tau\tau} method for acollinear taus as our signal channels. This technique ultimately gives a boost to the signal significance over the standard technique of using just the BtB signal channel. We evaluate both the 95% CL exclusion and 5\sigma discovery reach in the m_A vs. \tan\beta plane for present LHC with 139 fb^{-1}, Run 3 with 300 fb^{-1} and high luminosity LHC (HL-LHC) with 3000 fb^{-1} of integrated luminosity. For \tan\beta =10, the exclusion limits range up to m_A\sim 1, 1.1 and 1.4 TeV, respectively. These may be compared to the range of m_A values gleaned from a statistical analysis of the string landscape wherein m_A can range up to ~8 TeV.

   hep-phSymmetry(2022)·20 citations
2. 02*

   SQM2022: Theoretical Summary

   Berndt Müller🇺🇸

   Written version of the theoretical summary lecture presented at the Strangeness in Quark Matter 2022 conference.

   hep-phnucl-thEPJ Web Conf.(2023)·2 citations
3. 03*

   Estimating the realistic start-up of spontaneous emission in the supercritical QED

   A.Krasnov🇷🇺 · K.Sveshnikov🇷🇺

   The scenario of spontaneous positron emission, caused by the supercritical Coulomb source with charge $Z$ and size $R$, is explored in essentially non-perturbative approach with emphasis on the vacuum energy ${\mathcal{E}}_{VP}$\footnote{Throughout the paper the abbreviation "VP"\, stands for "vacuum polarization"\,.}, considered as a function of $R$ with fixed $Z>Z_{cr,1}\simeq 170$. It is shown that in the supercritical region the behavior of ${\mathcal{E}}_{VP}(R)$ turns out to be quite different in dependence on the value of the Coulomb charge $Z$. In particular, spontaneous emission becomes a visible effect starting only from $Z\sim 300$. With further growth of $Z$ its intensity increases very rapidly, which opens up the possibility for unambiguous detection. For such $Z$ the appearing picture of spontaneous emission turns out to be well-established and quite transparent in terms of the resonance decay combined with vacuum shells formation. The intimate, but crucial role of ${\mathcal{E}}_{VP}(R)$ in the total energy balance in the system is outlined. The additional problems of spontaneous emission, caused by the lepton number conservation, are also discussed.

   hep-ph2 citations
4. 04*

   Softly broken symmetries in the 2HDM -- an invariant formulation

   Pedro M. Ferreira🇵🇹 · Bohdan Grzadkowski🇵🇱 · Odd Magne Ogreid🇳🇴 · Per Osland🇳🇴

   Soft breaking of a symmetry requires an invariance of the dimension-4 part of the Lagrangian and non-trivial variation of the lower-dimensional part. However, in general, separation between the dim-4 and lower-dimensional Lagrangian is not invariant with respect to basis transformations of fields. Therefore, a natural question of the physical meaning of soft symmetry breaking arises. This problem is addressed here in the framework of two-Higgs-Doublet Models (2HDM). It has been shown, within these models, that in spite of the ambiguity corresponding to the separation between dim-4 and the lower-dimension Lagrangian, implications of the soft symmetry breaking could be formulated in terms of observables, i.e., they are physical and measurable. There are six global symmetries that can be imposed on the scalar sector of the generic 2HDM. Necessary and sufficient tree-level conditions for soft breaking of all of them have been formulated in terms of observables.

   hep-phJHEP(2023)·10 citations
5. 05*

   New types of instability and CP violation in electroweak theory

   M. Yoshimura🇯🇵

   It is known that the Schwinger mechanism of vector-like QED theory is afflicted by a logarithmic singularity under background electromagnetic field due to a hypothetical massless charged fermion. We extend singularity analysis to a more realistic case of the chiral electroweak theory, to show that the effective lagrangian under background gauge field at zero temperature exhibits a similar instability proportional to $\ln (1/m_{\nu }^2)$ with $m_{\nu }$ a small neutrino mass. Moreover, the effective lagrangian of chiral fermion loop contains CP violating pieces proportional to background gauge fields in odd powers of ${\vec{E}}_Z\cdot {\vec{B}}_Z$ or $({\vec{E}}_{W^{+}}\cdot {\vec{B}}_{W^{-}}+{\vec{E}}_{W^{-}}\cdot {\vec{B}}_{W^{+}})/2$. This brings in a new source of CP violation and time-reversal symmetry violation in the standard particle theory independent of the Kobayashi-Maskawa phase of quark mass mixing matrix. The effective action in thermal equilibrium at finite temperature $T$ is then calculated under background SU(2)$\times$U(1) gauge fields in the spontaneously broken phase. An even more singular power-law behavior $\propto (m_{\nu }T{)}^{-5/2}$ is found and it contains CP violating term as well. The case of Majorana neutrino satisfies almost all necessary conditions to generate a large lepton number asymmetry, though not necessarily convertible to a baryon asymmetry due to lower cosmic temperatures at which this may occur.

   hep-phastro-ph.COhep-exhep-th0 citations
6. 06*

   Amplitude/Operator Basis in Chiral Perturbation Theory

   Ian Low🇺🇸 · Jing Shu🇨🇳 · Ming-Lei Xiao🇺🇸 · Yu-Hui Zheng🇨🇳

   We establish a systematic construction of the on-shell amplitude/operator basis for Chiral Perturbation Theory (ChPT) in $D=4$ spacetime dimensions and with an arbitrary number of flavors $N_f$. For kinematic factors, we employ spinor-helicity variables to construct the soft blocks, which are local amplitudes satisfying the Adler's zero condition, as well as to take into account the reduction in the kinematic basis due to the Gram determinant, which arises at $O(p^{10})$ when the number of multiplicity $N$ in an amplitude becomes large: $N>D$. For flavor factors, we include group-theoretic relations at small $N_f$, $N_f\le N$, which decreases the flavor basis. The result is obtained by adapting the Young tensor method of constructing the operator basis for generic effective field theories to the case of non-linearly realized symmetries. Working in the massless quark limit, we present purely mesonic operators for both even- and odd-parity at $O(p^6)$ and $O(p^8)$ for $N=6$ and arbitrary $N_f$, and establish a direct correspondence between the amplitude basis and the operator basis. Furthermore, the redundancy due to the Gram determinant is studied at $O(p^{10})$ for $N=6,8$ and 10.

   hep-phhep-thnucl-thJHEP(2023)·17 citations
7. 07*

   Heavy-Flavor-Conserving Hadronic Weak Decays of Charmed and Bottom Baryons: an Update

   Hai-Yang Cheng🇹🇼 · Chia-Wei Liu🇨🇳 · Fanrong Xu🇨🇳

   This paper serves as an update of the previous work entitled ``Heavy-Flavor-Conserving Hadronic Weak Decays of Charmed and Bottom Baryons". We make an improvement on the bag wave functions by removing the center-of-mass motion of the bag. All the baryon matrix elements are now calculated under the same framework without introducing new parameters. The matrix elements of 4-quark operators are found to be nearly twice larger than the previous ones. The calculated branching fractions of ${\Xi }_c^0\to {\Lambda }_c^{+}{\pi }^{-}$ and ${\Xi }_b^{-}\to {\Lambda }_b^0{\pi }^{-}$ are both in agreement with current experimental results. For the yet-to-be-measured heavy-flavor-conserving decays, we find $\mathcal{B}({\Xi }_c^{+}\to {\Lambda }_c^{+}{\pi }^0)=(13.8\pm 1.4)\times 10^{-3}$, $\mathcal{B}({\Xi }_b^0\to {\Lambda }_b^0{\pi }^0)=(2.6\pm 0.3)\times 10^{-3}$, $\mathcal{B}({\Omega }_c^0\to {\Xi }_c^{+}{\pi }^{-})=(2.0\pm 0.2)\times 10^{-3}$ and $\mathcal{B}({\Omega }_c^0\to {\Xi }_c^0{\pi }^0)=(1.1\pm 0.1)\times 10^{-3}$. They are all accessible to LHCb, Belle and Belle II and can be tested in the near future.

   hep-phhep-exPRD(2022)·18 citations
8. 08*

   $B$-anomalies in a twin Pati-Salam theory of flavour including the 2022 LHCb $R_{K^{(\ast )}}$ analysis

   Mario Fernández Navarro🇬🇧 · Stephen F. King🇬🇧

   We perform a comprehensive phenomenological analysis of the twin Pati-Salam theory of flavour, focussing on the parameter space relevant for interpreting the $B$-anomalies via vector leptoquark $U_1$ exchange. This model provides a very predictive framework in which the $U_1$ couplings and the Yukawa couplings find a common origin via mixing of chiral quarks and leptons with vector-like fermions, providing a direct link between the $B$-anomalies and the fermion masses and mixing. We propose and study a simplified model with three vector-like fermion families, in the massless first family approximation, and show that the second and third family charged fermion masses and mixings and the $B$-anomalies can be simultaneously explained and related. The model has the proper flavour structure to be compatible with all low-energy observables, and leads to predictions in promising observables such as $\tau \to 3\mu$, $\tau \to \mu \gamma$ and $B\to K^{(\ast )}\nu \bar{\nu }$ at Belle II and LHCb. The model also predicts a rich spectrum of TeV scale gauge bosons and vector-like fermions, all accessible to the LHC. In this updated version we have included an extended analysis considering the new 2022 LHCb data on $R_{K^{(\ast )}}$, which has slightly shifted the preferred parameter space with respect to the 2021 case. The model can still explain the $R_{D^{(\ast )}}$ anomalies at 1$\sigma$ in a narrow window, however we expect small deviations from the SM on the $R_{K^{(\ast )}}$ ratios, to be tested in the future via more precise measurements by the LHCb collaboration. We also predict $\Delta R_D=\Delta R_{D^{\ast }}$, with future measurements shifting the world averages to slightly smaller central values.

   hep-phJHEP(2023)·46 citations
9. 09*

   $H\to \gamma \gamma$ to all orders in ${\alpha }_s$ in the large-${\beta }_0$ limit of QCD

   D. Boito🇧🇷 · G. das Neves🇧🇷 · J. Piclum🇩🇪

   In this note, we present the result for the QCD corrections to the decay of the Higgs boson into two photons in the large-${\beta }_0$ limit of QCD, providing the first two terms in the heavy-top expansion. From our results, one can easily read off the exact leading-$n_f$ QCD contributions in analytic form to all orders in the strong coupling, ${\alpha }_s$, where $n_f$ is the number of massless quarks, and identify the leading renormalon singularities. We give explicit results for the leading-$n_f$ coefficients at 6 and 7 loops and use the large-${\beta }_0$ result to speculate about the size of yet unknown (but small) higher-order contributions to the QCD series.

   hep-phPRD(2022)·5 citations
10. 10*

    Heavy quark contribution to the electromagnetic properties of the nucleon

    Stanley J. Brodsky🇺🇸 · Valery E. Lyubovitskij🇩🇪 · Ivan Schmidt🇨🇱

    Quantum chromodynamics (QCD) predicts the existence of both nonperturbative intrinsic and perturbative extrinsic heavy quark contributions to the fundamental structure of hadrons. The existence of intrinsic charm at the 3-standard-deviation level in the proton has recently been established from structure function measurements by the NNPDF Collaboration. Here we revisit the physics of intrinsic heavy quarks using light-front holographic QCD (LFHQCD) - a novel comprehensive approach to hadron structure which provides detailed predictions for dynamical properties of the hadrons, such as form factors, distribution amplitudes, structure functions, etc. We will extend this nonperturbative light-front QCD approach to study the heavy quark-antiquark contribution to the electromagnetic properties of nucleon. Our framework is based on a study of the eigenfunctions of the QCD light-front Hamiltonian, the frame-independent light-front wave functions (LFWFs) underlying hadron dynamics. We analyze the heavy quark content in the proton, induced either directly by the nonperturbative $|uud+Q\bar{Q}⟩$ Fock state or by the $|uud+g⟩$ Fock state, where the gluon splits into a heavy quark-antiquark pair. The specific form of these LFWFs are derived from LFHQCD. Using these LFWFs, we construct light-front representations for the heavy quark-antiquark asymmetry, the electromagnetic form factors of nucleons induced by heavy quarks, including their magnetic moments and radii.

    hep-phPRD(2022)·5 citations
11. 11*

    Characterising Dark Matter-induced neutrino potentials

    Gabriel M. Salla🇧🇷

    In this paper we explore interactions between neutrinos and Dark Matter. In particular, we study how the propagation of astrophysical neutrinos can be modified by computing the most general potential generated by the galactic DM background. We use on-shell techniques to compute this potential in a completely model independent way and obtain an expression valid for any Dark Matter mass and spin. Afterwards, we use this expression to analyse under what circumstances such potential can be important at the phenomenological level, and we find that under some assumptions only ultra light scalar Dark Matter could be of any relevance to oscillation experiments.

    hep-phEPJC(2023)·7 citations
12. 12*

    On the Suppression of the Dark Matter-Nucleon Scattering Cross Section in the SE${}_6$SSM

    Roman Nevzorov🇷🇺

    In the E6 inspired $U(1{)}_N$ extension of the minimal supersymmetric (SUSY) standard model (MSSM) a single discrete ${\tilde{Z}}_2^H$ symmetry permits suppressing rapid proton decay and non-diagonal flavour transitions. If matter parity and ${\tilde{Z}}_2^H$ symmetry are preserved this SUSY model (SE4-6$SSM) may involve two dark matter candidates. In this article we study a new modification of the SE6SSM in which the cold dark matter is composed of gravitino and the lightest neutral exotic fermion. We argue that in this case the dark matter-nucleon scattering cross section can be considerably smaller than the present experimental limit.

    hep-phastro-ph.COgr-qchep-thSymmetry(2022)·8 citations
13. 13*

    Connecting Seesaw Effective Field Theory to Full Theory via Flavor Invariants

    Bingrong Yu🇨🇳 · Shun Zhou🇨🇳

    The canonical seesaw models are one of the simplest and most natural scenarios that can account simultaneously for neutrino masses and matter-antimatter asymmetry in our universe. Below the seesaw scale, one can integrate out the heavy degrees of freedom to construct the seesaw effective field theory (SEFT). In this talk, we investigate the connection between the full seesaw model and the low-energy SEFT from a brand-new perspective: the invariant theory. Using the powerful tool of Hilbert series, we demonstrate the intimate relation between the flavor space of the SEFT and that of its ultraviolet theory. Through the matching of flavor invariants, it is revealed that the precise measurements of dimension-five and dimension-six operators in the SEFT at low energies are powerful enough to probe the full seesaw model, including CP violation necessary for successful leptogenesis.

    hep-phhep-thPoS(2022)·0 citations
14. 14*

    Longitudinal momentum fraction of heavy-flavor mesons in jets in high-energy nuclear collisions

    Yao Li🇨🇳 · Sa Wang🇨🇳 · Ben-Wei Zhang🇨🇳

    Heavy-flavor jets are powerful tools to gain insight into the in-medium partonic energy-loss mechanisms and the quark-gluon plasma's (QGP) transport properties in high-energy nuclear collisions. In this work we present the first theoretical study of the longitudinal momentum fraction $z_{||}$ carried by heavy-flavor mesons in jets in Pb+Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV. The p+p baseline is provided by POWHEG+PYTHIA8, which matches the next-to-leading-order hard processes with the parton shower. We employ a Monte Carlo transport model, which considers the collisional and radiative partonic energy loss, to simulate the evolution of heavy-flavor jets in the expanding QGP medium. We observe steeper $z_{||}$ distributions of ${\mathrm{B}}^0$ jets compared to those of ${\mathrm{D}}^0$ jets at the same kinematics region in p+p collisions, which may be a hint of the harder jet fragmentation function of b jets compared to c jets in vacuum. In A+A collisions, it is shown that the jet quenching effect would generally decrease the values of $z_{||}$. We have made a systematical study on how several factors, including jet $p_{\mathrm{T}}$, jet radius $R$, and collision centrality, would influence the medium modification of $z_{||}$ distributions of a ${\mathrm{D}}^0$ jet. In addition, we predict visibly stronger nuclear modifications of ${\mathrm{B}}^0$-jet $z_{||}$ distributions compared to a ${\mathrm{D}}^0$ jet within the same $p_{\mathrm{T}}$ windows as a result of the much steeper initial $z_{||}$ distribution of the ${\mathrm{B}}^0$ jet in vacuum.

    hep-phnucl-thPRC(2023)·15 citations
15. 15*

    Comment on "Damping of neutrino oscillations, decoherence and the lengths of neutrino wave packets''

    B.J.P. Jones🇺🇸

    We point out three apparent inconsistencies in the treatment of oscillation coherence from reactor neutrino and source neutrino experiments in recent paper "Damping of neutrino oscillations, decoherence and the lengths of neutrino wave packets''. First, that the dependence of the oscillation probability upon the subsequent interactions of entangled recoil particles implies causality violations and in some situations superluminal signaling; second, that integrating over a non-orthogonal basis for the entangled recoil leads to unphysical effects; and third, that the question of what interactions serve to measure the position of the initial state particle remains ambiguous. These points taken together appear to undermine the claim made therein that the effects of wave packet separation must be strictly unobservable in reactor and radioactive source based neutrino experiments.

    hep-ph14 citations
16. 16*

    New Opportunities for Detecting Axion-Lepton Interactions

    Wolfgang Altmannshofer🇺🇸 · Jeff A. Dror🇺🇸 · Stefania Gori🇺🇸

    We revisit the theory and constraints on axion-like particles (ALPs) interacting with leptons. We clarify some subtleties in the constraints on ALP parameter space and find several new opportunities for ALP detection. We identify a qualitative difference between weak-violating and weak-preserving ALPs, which dramatically change the current constraints due to possible "energy enhancements" in various processes. This new understanding leads to additional opportunities for ALP detection through charged meson decays (e.g., ${\pi }^{+}\to e^{+}\nu a$, $K^{+}\to e^{+}\nu a$) and $W$ boson decays. The new bounds impact both weak-preserving and weak-violating ALPs and have implications for the QCD axion and addressing experimental anomalies using ALPs.

    hep-phhep-exPRL(2023)·54 citations
17. 17*

    Charting the Higgs self-coupling boundaries

    Gauthier Durieux🇨🇭 · Matthew McCullough🇨🇭 · Ennio Salvioni🇮🇹

    Could new physics first manifest itself in Higgs self-coupling measurements? In other words, how large could deviations in the Higgs self-coupling be, if other Higgs and electroweak measurements are compatible with Standard Model predictions? Using theoretical arguments supported by concrete models we derive a bound on the ratio of self-coupling to single-Higgs coupling deviations in ultraviolet completions of the Standard Model where parameters are not fine-tuned. Broadly speaking, a one-loop hierarchy is allowed. We thus stress that self-coupling measurements at the LHC and future colliders probe uncharted parameter space, presenting discovery potential even in the absence of emerging hints in single-Higgs coupling measurements. For instance, if other observables show less than two-sigma deviations by the end of the LHC programme, the Higgs self-coupling deviations could still exceed 200% in the models discussed, without introducing fine-tuning of ultraviolet parameters.

    hep-phhep-exJHEP(2022)·39 citations
18. 18*

    Strongest atomic physics bounds on Non-Commutative Quantum Gravity Models

    Kristian Piscicchia🇮🇹 · Andrea Addazi🇨🇳 · Antonino Marciano🇨🇳 · Massimiliano Bazzi🇮🇹 · Michael Cargnelli🇦🇹 · Alberto Clozza🇮🇹 · Luca De Paolis🇮🇹 · Raffaele Del Grande🇮🇹 · Carlo Guaraldo🇮🇹 · Mihail Antoniu Iliescu🇮🇹 · Matthias Laubenstein🇮🇹 · Johann Marton🇦🇹 and 9 other authors

    Investigations of possible violations of the Pauli Exclusion Principle represent critical tests of the microscopic space-time structure and properties. Space-time non-commutativity provides a class of universality for several Quantum Gravity models. In this context the VIP-2 Lead experiment sets the strongest bounds, searching for Pauli Exclusion Principle violating atomic-transitions in lead, excluding the $\theta$-Poincaré Non Commutative Quantum Gravity models far above the Planck scale for non-vanishing ${\theta }_{\mu \nu }$ ``electric-like'' components, and up to $6.9\cdot 10^{-2}$ Planck scales if ${\theta }_{0i}=0$.

    ↳ hep-thgr-qchep-phPRL(2022)·25 citations
19. 19*

    Charged Lepton Flavor Violation

    Sacha Davidson🇫🇷 · Bertrand Echenard🇺🇸 · Robert H. Bernstein🇺🇸 · Julian Heeck🇺🇸 · David G. Hitlin🇮🇳

    This reports summarizes the activities of the Charged Lepton Flavor Violation group of the 2022 Community Summer Study. Charged lepton flavor violating reactions provide unique information on the scale and dynamics of flavor generation, and more generally a wide range of New Physics scenarios, complementing direct searches performed at collider and neutrino physics experiments. These processes already probe mass scales up to thousands of TeV, and an observation would be an unambiguous signature of physics beyond the Standard Model. We review the current status and future experimental opportunities in muon, tau and heavy state transitions, with a focus on US-led initiatives.

    ↳ hep-exhep-ph61 citations
20. 20*

    Imprints of clustering in multiplicity fluctuations

    A. Bazgir🇵🇱 · V.Z. Reyna Ortiz🇵🇱 · M. Rybczynski🇵🇱 · U. Shah🇵🇱 · Z. Wlodarczyk🇵🇱

    In this paper, we investigate the multiplicity fluctuations of charged particles observed in high-energy nuclear collisions and relate them to the size of hadronizing systems which happen during such processes. We use the average multiplicities $⟨N⟩$ and variances $Var\left(N\right)$ of multiplicity distributions of charged particles produced in centrality selected collisions of relativistic heavy-ion nuclei to evaluate the dynamic variable $\Omega$ and study its dependence on the size of colliding nuclei. We connect the observed system-size dependence of multiplicity fluctuations with the clustering phenomena and the finiteness of the hadronizing sources and the thermal bath.

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

    Directed flow in relativistic resistive magneto-hydrodynamic expansion for symmetric and asymmetric collision systems

    Kouki Nakamura🇯🇵 · Takahiro Miyoshi🇯🇵 · Chiho Nonaka🇯🇵 · Hiroyuki R. Takahashi🇯🇵

    We construct a dynamical model for high-energy heavy-ion collision based on the relativistic resistive magneto-hydrodynamic framework. Using our newly developed (3+1)-dimensional relativistic resistive magneto-hydrodynamics code, we investigate magneto-hydrodynamic expansion in symmetric and asymmetric collision systems as a first application to high-energy heavy-ion collisions. As a realistic initial condition for electromagnetic fields, we consider the solutions of the Maxwell equations with the source term of point charged particles moving in the direction of the beam axis, including finite constant electrical conductivity of the medium. We evaluate the directed flow in the symmetric and asymmetric collisions at RHIC energy. We find a significant effect of finite electrical conductivity on the directed flow in the asymmetric collision system. We confirm that a certain amount of energy transfer by dissipation associated with Ohmic conduction occurs in the asymmetric collision system because of asymmetry of the electric field produced by two different colliding nuclei. Because this energy transfer makes the pressure gradient of the medium flatter, the growth of directed flow decreases.

    ↳ nucl-thhep-phnucl-exPRC(2023)·18 citations
22. 22*

    Dress code for infrared safe scattering in QED

    Hayato Hirai🇯🇵 · Sotaro Sugishita🇯🇵

    We study the $S$-matrix and inclusive cross-section for general dressed states in quantum electrodynamics. We obtain an infrared factorization formula of the $S$-matrix elements for general dressed states. It enables us to study what dressed states lead to infrared-safe $S$-matrix elements. The condition for dressed states can be interpreted as the memory effect which is nothing but the conservation law of the asymptotic symmetry. We derive the generalized soft photon theorem for general dressed states. We also compute inclusive cross-section using general dressed states. It is necessary to use appropriate initial and final dressed states to evaluate interference effects, which cannot be computed correctly by using Fock states due to the infrared divergence.

    ↳ hep-thgr-qchep-phPTEP(2023)·13 citations
23. 23*

    Instability of bubble expansion at zero temperature

    Wen-Yuan Ai🇬🇧 · Juan S. Cruz🇩🇰 · Bjorn Garbrecht🇩🇪 · Carlos Tamarit🇩🇪

    In the context of false vacuum decay at zero temperature, it is well known that bubbles expand with uniform proper acceleration. We show that this uniformly accelerating expansion suffers from an instability related to the bubble size. This can be observed in Minkowski spacetime as a tachyonic mode in the spectrum of fluctuations for the energy functional in the reference frame in which the uniformly accelerating bubble wall appears static. In such a frame, arbitrary small perturbations cause an amplifying departure from the static wall solution. This implies that the nucleated bubble is not a critical point of the energy functional in the rest frame of nucleation but becomes one in the accelerating frame. The aforementioned instability for vacuum bubbles can be related to the well-known instability for the nucleated critical static bubbles during finite-temperature phase transitions in the rest frame of the plasma. It is therefore proposed that zero-temperature vacuum decays as seen from accelerating frames have a dual description in terms of finite-temperature phase transitions.

    ↳ hep-thhep-phPRD(2023)·8 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.