Wed·Dec 14, 2022Wednesday·December 14, 2022

1. 01*

   Light Scalars at FASER

   Shuailong Li · Huayang Song · Shufang Su · Wei Su

   FASER, the ForwArd Search ExpeRiment, is a currently operating experiment at the Large Hadron Collider (LHC) that can detect light long-lived particles produced in the forward region of the LHC interacting point. In this paper, we study the prospect of detecting light CP-even and CP-odd scalars at FASER and FASER 2. Considering a model-independent framework describing the most general interactions between a CP-even or CP-odd scalar and SM particles using the notation of coupling modifiers in the effective Lagrangian, we develop the general formalism for the scalar production and decay. We then analyze the FASER and FASER 2 reaches of light scalars in the large $\tan \beta$ region of the Type-I two Higgs double model as a case study, in which light scalars with relatively long lifetime could be accommodated. In the two benchmark scenarios we considered, the light (pseudo)scalar decay length varies in $(10^{-8},10^5)$ meters. Both FASER and FASER 2 can probe a large part of the parameter space in the large $\tan \beta$ region up to $10^5$, extending beyond the constraints of the other existing experiments.

   hep-phJHEP(2023)·29 citations
2. 02*

   Glueballs in Radiative $J/\psi$ Decays

   Eberhard Klempt🇩🇪

   The scalar glueball is observed in a coupled-channel analysis of the $S$-wave amplitude from BESIII data on radiative $J/\psi$ decays and further data. Ten scalar isoscalar resonances were required to fit the data. Five of them were interpreted as mainly-singlet, five as mainly-octet resonances in SU(3). The yield of resonances showed a striking peak with properties expected from a scalar glueball. The $D$ wave amplitude in the BESIII data on radiative $J/\psi$ decays reveales a high-mass structure which can be described by a single Breit-Wigner or by the sum of three $\varphi \varphi$ resonances interpreted as tensor glueballs a long time ago. The structure - and further tensor resonances observed in radiative $J/\psi$ decays - are tentatively interpreted as tensor glueball. In $J/\psi$ decays into $\gamma {\pi }^0{\pi }^0{\eta }^{\prime }$ several resonances are reported. The possibility is discussed that the pseudoscalar glueball might be hidden in these data.

   hep-phEPJ Web Conf.(2022)·0 citations
3. 03*

   Primary Observables for Indirect Searches at Colliders

   Spencer Chang🇺🇸 · Miranda Chen🇺🇸 · Da Liu🇺🇸 · Markus A. Luty🇺🇸

   We consider the complete set of observables for collider searches for indirect effects of new heavy physics. They consist of $SU(3{)}_{\mathrm{C}}\times U(1{)}_{\mathrm{EM}}$ invariant interaction terms/operators that parameterize deviations from the Standard Model. We show that, under very general assumptions, the leading deviations from the Standard Model are given by a finite number of `primary' operators, with the remaining operators given by `Mandelstam descendants' whose effects are suppressed by powers of Mandelstam variables divided by the mass scale $M$ of the heavy physics. We explicitly determine all 3 and 4-point primary operators relevant for Higgs signals at colliders by using the correspondence between on-shell amplitudes and independent operators. We give a detailed discussion of the methods used to obtain this result, including a new analytical method for determining the independent operators. The results are checked using the Hilbert series that counts independent operators. We also give a rough sketch of the phenomenology, including unitarity bounds on the interaction strengths and rough estimates of their importance for Higgs decays at the HL-LHC. These results motivate further exploration of Higgs decays to $Z\bar{f}f$, $W\bar{f}{f}^{\prime }$, $\gamma \bar{f}f$, and $Z\gamma \gamma$.

   hep-phhep-exhep-thJHEP(2023)·17 citations
4. 04*

   Exploring the vacuum structure of gravitationally induced neutrino masses

   Carlos Henrique de Lima🇨🇦 · Daniel Stolarski🇨🇦

   In this work, we explore the proposed mechanism in which the gravitational $\theta$ anomaly generates neutrino masses. We highlight that the leading renormalizable interactions of the neutrino condensate forbid the possibility of generating hierarchical masses consistent with observation. This conclusion still holds when Standard Model loop corrections are accounted for. We show that higher-dimensional operators can alleviate this problem. The higher-dimensional operators could be generated from the gravitational anomaly itself, but there is no clear way to know without a deeper understanding of the low-energy description of this mechanism. Because of that, we explore the possibility of new particles generating neutrino mass splittings. We show that both new particles that alter the scalar potential of the condensate or new particles in loops for the neutrino self-energy can solve this problem.

   hep-phhep-thPRD(2023)·8 citations
5. 05*

   $t\bar{t}b\bar{b}$ predictions at NLO in QCD and $b$-jet modelling

   Michele Lupattelli🇩🇪

   In this contribution we report on the latest theoretical predictions for $t\bar{t}b\bar{b}$. These results are obtained for the fully decayed final state $pp\to e^{+}{\nu }_e{\mu }^{-}{\nu }_{\mu }b\bar{b}b\bar{b}$ at next-to-leading order accuracy in QCD. We present predictions with full off-shell effects and in the Narrow Width Approximation. Specifically, we report on the size of the NLO QCD corrections and the size of the full off-shell effects. Finally, we study the nature of the $b$-jets present in the final state.

   hep-phPoS·0 citations
6. 06*

   Signal-background interference effects in Higgs-mediated diphoton production beyond NLO

   Piotr Bargiela🇬🇧 · Federico Buccioni🇬🇧 · Fabrizio Caola🇬🇧 · Federica Devoto🇬🇧 · Andreas von Manteuffel🇺🇸 · Lorenzo Tancredi🇩🇪

   In this paper we consider signal-background interference effects in Higgs-mediated diphoton production at the LHC. After reviewing earlier works that show how to use these effects to constrain the Higgs boson total decay width, we provide predictions beyond NLO accuracy for the interference and related observables, and study the impact of QCD radiative corrections on the Higgs width determination. In particular, we use the so-called soft-virtual approximation to estimate interference effects at NNLO in QCD. The inclusion of these effects reduce the NNLO prediction for the total Higgs cross-section in the diphoton channel by about 1.7%. We study in detail the impact of QCD corrections on the Higgs-boson line-shape and its implications for the Higgs width extraction. Assuming an experimental resolution of about 150~MeV on interference-induced modifications of the Higgs-boson line-shape, our NNLO analysis shows that one could constrain the Higgs-boson total width to about 10-20 times its Standard Model value.

   hep-phhep-exEPJC(2023)·13 citations
7. 07*

   Comparative study of the 1-2 exchange symmetries in neutrino frameworks with global and local validities

   Hisakazu Minakata🇺🇸

   A new picture ``one-resonance - one-symmetry'' has been proposed recently to reveal nature of the reparametrization symmetry in neutrino oscillation in matter and where it resides: Symmetry of $i\leftrightarrow j$ state-exchange type exists at around a resonance with $i$ and $j$ being the states which participate in the level crossing. Consistently, the 1-2 and 1-3 state exchange symmetries are identified at around the solar and atmospheric resonances, respectively, in the locally-valid frameworks. On the other hand, the Denton {\it et al.} (DMP) perturbation theory, a globally-valid framework, has the 1-2 exchange symmetry which is akin to the one in the aforementioned solar-resonance perturbation (SRP) theory. In our picture, the symmetry must be associated with the resonance, not the framework, and if so these two 1-2 symmetries must be identical to each other. We conduct a comparative study of the 1-2 symmetries possessed by SRP and DMP to confirm their identity. An almost identity is verified, but in a highly nontrivial way.

   hep-phActa Phys.Polon.B(2023)·2 citations
8. 08*

   Spherically Symmetric Noncommutative Spacetime via Exotic Atomic Transitions

   Junlin Wu🇨🇳 · Horan Tsui🇨🇳 · Bowen Tong🇨🇳 · Shin-Ted Lin🇨🇳 · Shu-Kui Liu🇨🇳 · Muhammed Deniz🇨🇳 · Henry T. Wong🇹🇼 · Qian Yue🇨🇳

   In discussing non-commutative spacetime, the generally studied $\theta$-Poincare model is inconsistent with bound states. In this Letter, we develop the formalism and study the phenomenology of another model ${\mathcal{B}}_{\chi \hat{n}}$ by the twisted permutation algebra and extend the Pauli Exclusion Principle(PEP) into non-commutative spacetime. The model also implies time quantization and can avoid UV/IR mixing. Applying it to atomic systems, we show that the model with newly induced phase factors can cause exotic transitions consisting of three electrons in the 1S orbit of atoms. The transition rate is derived, and the upper bound of non-commutative parameter $\chi$ is thus set by utilizing data from the low-energy and low-background experiments, where strongest constraint $\chi \le 4.05\times 10^{-30}$ eV${}^{-1}$ at 90\% C.L. is given by XENONnT, with the time quanta $\Delta t\sim 2.67\times 10^{-45}s$, equivalent to twenty times smaller than the Planck time.

   hep-ph0 citations
9. 09*

   Analytic result for the top-quark width at next-to-next-to-leading order in QCD

   Long-Bin Chen🇨🇳 · Hai Tao Li🇨🇳 · Jian Wang🇨🇳 · Yefan Wang🇨🇳

   We present the first full analytic results of next-to-next-to-leading order (NNLO) QCD corrections to the top-quark decay width $\Gamma (t\to Wb)$ by calculating the imaginary part of three-loop top-quark self-energy diagrams. The results are all expressed in terms of harmonic polylogarithms and valid in the whole region $0\le m_W^2\le m_t^2$. The expansions in the $m_W^2\to 0$ and $m_W^2\to m_t^2$ limits coincide with previous studies. Our results can also be taken as the exact prediction for the lepton invariant mass spectrum in semileptonic $b\to u$ decays. We also analytically compute the decay width including the off-shell $W$ boson effect up to NNLO in QCD for the first time. Combining these contributions with electroweak corrections and the finite $b$-quark mass effect, we determine the most precise top-quark width to be 1.331 GeV for $m_t=172.69$ GeV. The total theoretical uncertainties including those from renormalization scale choice, top-quark renormalization scheme, input parameters, and missing higher-order corrections are scrutinized and found to be less than $1\%$.

   hep-phhep-exPRD(2023)·25 citations
10. 10*

    Study of strange quark density fluctuations in Au+Au Collisions at $\sqrt{s_{NN}}$ = 7.7-200 GeV from AMPT Model

    Junaid Tariq🇵🇰 · Sumaira Ikram🇵🇰 · M. U. Ashraf🇧🇪

    The strangeness production is an important observable to study the QCD phase diagram. The yield ratios of strange quark can be helpful to search for the QCD critical end point (CEP) and/or first-order phase transition. In this work, we studied the production of $K^{\pm }$, ${\Xi }^{-}({\bar{\Xi }}^{+})$, $\varphi$ and $\Lambda (\bar{\Lambda })$ in {\auau} collisions at {\sqrtsNN} = 7.7, 11.5, 14.5, 19.6, 27, 39, 54.4, 62.4, and 200 GeV from A Multi-Phase Transport model with string melting version (AMPT-SM). We calculated the invariant yield of these strange hadrons using a different set of parameters compared to those reported in earlier studies and also by varying the hadronic cascade time ($t_{max}$) in the AMPT-SM model. We also calculated the yield ratios, ${\mathcal{O}}_{K^{\pm }-{\Xi }^{-}({\bar{\Xi }}^{+})-\varphi -\Lambda (\bar{\Lambda })}$ which are reported as sensitive to the strange quark density fluctuations and found that the AMPT-SM model fails to describe the non-monotonic trend observed by the experimental data. The negative particle ratio are found to be higher than the ratio of positive particles which is consistent with the experimental data. A significant effect is also seen on these ratios by varying the $t_{max}$. For a crossover transition between the Quark-Gluon Plasma (QGP) and hadronic matter, the double yield ratios considered in the present study based on AMPT-SM model do not show any non-monotonic behaviors and thus providing a baseline for the search of CEP, because there is no first-order or second-order phase transition in the AMPT model. The more realistic equation of state based dynamical modeling is still required for the heavy-ion collisions in order to extract the definite physics conclusion about the non-monotonic energy dependence behavior.

    hep-phEPJA(2023)·2 citations
11. 11*

    Spin-orbit amplitudes for decays with arbitrary spin

    Xiao-yu Li🇨🇳 · Xiang-Kun Dong🇨🇳 · Hao-Jie Jing🇨🇳

    In this paper, we propose a method to construct the decay amplitudes in the orbital ($L$) and spin ($S$) coupling scheme for particles with arbitrary spins. For the $1\to 2$ decay with only massive particles involved, the angular dependence is completely encoded in the angular momentum part, and the spins of daughter particles are coupled in the rest frame of the mother particle, which contributes only a constant factor. For the sequential decay, the total amplitude is constructed by the two $1\to 2$ amplitudes evaluated in the rest frame of their own mother particles, and then they are transformed to the common frame, usually chosen as the laboratory frame, by certain Lorentz transformations. In this way, it is easy to add the amplitudes of possible different decay chains coherently. If massless particles show up in the final states, the polarizations are expressed in helicity basis and the amplitudes are modified correspondingly.

    hep-phhep-exNPA(2023)·4 citations
12. 12*

    An updated view on the ATOMKI nuclear anomalies

    Daniele Barducci🇮🇹 · Claudio Toni🇮🇹

    In view of the latest experimental results recently released by the ATOMKI collaboration, we critically re-examine the possible theoretical interpretation of the observed anomalies in terms of a new BSM boson $X$ with mass $\sim 17$MeV. To this end we employ a multipole expansion method and give an estimate for the range of values of the nucleon couplings to the new light state in order to match the experimental observations. Our conclusions identify the axial vector state as the most promising candidate, while other spin/parity assignments seems disfavored for a combined explanation. This results is however based on an order of magnitude estimate for the, currently unknown, axial nuclear matrix element of the ${}^{12}$C transition, that needs then to be evaluated before being able to draw a definite conclusion. Intriguingly, an axial vector state can also simultaneously accommodate other experimental anomalies, {\emph{i.e.}} the KTeV anomaly in ${\pi }^0\to e^{+}{e}^{-}$ decay while being compatible with the conflicting measurements of the anomalous magnetic moment of the electron $(g-2{)}_e$ and other constraints on the electron couplings of the $X$ boson. The PADME experiment will completely cover the relevant region of the parameter space, thus allowing for a strong test of the existence of the $X$ particle.

    hep-phhep-exJHEP(2023)·51 citations
13. 13*

    Muon-electron scattering at NNLO

    A. Broggio🇮🇹 · T. Engel🇨🇭 · A. Ferroglia🇺🇸 · M. K. Mandal🇮🇹 · P. Mastrolia🇮🇹 · M. Rocco🇨🇭 · J. Ronca🇮🇹 · A. Signer🇨🇭 · W. J. Torres Bobadilla🇩🇪 · Y. Ulrich🇬🇧 · M. Zoller🇨🇭

    We present the first calculation of the complete set of NNLO QED corrections for muon-electron scattering. This includes leptonic, non-perturbative hadronic, and photonic contributions. All fermionic corrections as well as the photonic subset that only corrects the electron or the muon line are included with full mass dependence. The genuine four-point two-loop topologies are computed as an expansion in the small electron mass, taking into account both, logarithmically enhanced as well as constant mass effects using massification. A fast and stable implementation of the numerically delicate real-virtual contribution is achieved by combining OpenLoops with next-to-soft stabilisation. All matrix elements are implemented in the McMule framework, which allows for the fully-differential calculation of any infrared-safe observable. This calculation is to be viewed in the context of the MUonE experiment requiring a background prediction at the level of 10 ppm. Our results thus represent a major milestone towards this ambitious precision goal.

    hep-phhep-exJHEP(2023)·40 citations
14. 14*

    Pinching instabilities in superconducting strings

    R. A. Battye🇬🇧 · S. J. Cotterill🇬🇧

    Superconducting cosmic strings can exhibit longitudinal, pinching instabilities in some regions of the parameter space. We make predictions about the onset of this instability using the thin string approximation (TSA) and develop an improved analysis that remains applicable for small wavelength perturbations, where the TSA breaks down. We use simulations of perturbed strings to assess the accuracy of the TSA, test the predictions of our new analysis and demonstrate an improvement over previous methods in the literature. Notably, it appears that the instabilities are typically present for a larger range of magnetic strings than previously expected, and we show examples of pinching instabilities also occurring in electric strings. However, both our simulations and predictions agree that strings near the chiral limit are free from pinching instabilities and in particular our results support our previously published claim that vortons can be stable to all classical perturbations if they are sufficiently large.

    hep-phastro-ph.COhep-thPRD(2023)·6 citations
15. 15*

    Oblique corrections from triplet quarks

    Francisco Albergaria🇵🇹 · Luís Lavoura🇵🇹 · Jorge C. Romão🇵🇹

    We present general formulas for the oblique-correction parameters $S$, $T$, $U$, $V$, $W$, and $X$ in an extension of the Standard Model having arbitrary numbers of singlet, doublet, and triplet quarks with electric charges $-4/3$, $-1/3$, $2/3$, and $5/3$ that mix with the standard quarks of the same charge.

    hep-phJHEP(2023)·3 citations
16. 16*

    The third peak structure in the double $J/\psi$ spectrum

    PengYu Niu🇨🇳 · Zhenyu Zhang🇨🇳 · Qian Wang🇨🇳 · Meng-Lin Du🇨🇳

    Recently, the CMS and ATLAS collaborations have reported their $J/\psi J/\psi$ and $J/\psi {\psi }^{\prime }$ invariant mass distributions, respectively, for searching for fully charmed tetraquarks. Both of them reported the existence of a peak structure around $7.2\text{gev}$. In this article, we exhibit the role of the ${\eta }_c(2S){\eta }_c(2S)$ channel, which is close to this peak position, by studying the $J/\psi J/\psi$ and $J/\psi {\psi }^{\prime }$ invariant mass distributions for the potential quantum numbers $J^{PC}=0^{++}$ or $2^{++}$ by considering both the coherence and incoherence with the background contribution. All these frameworks can describe the experimental data very well, however with different pole structures. For instance, in the case of $2^{++}$ description of these structures, there always exists a pole slightly below the $J/\psi J/\psi$ threshold. For the $0^{++}$ case, a similar pole can also be found below the $J/\psi J/\psi$ threshold however with a much lower mass. More importantly, the number of the poles is found to be case-dependent. For the $0^{++}$ ($2^{++}$) case, the peak structure around $7.2\text{gev}$ can (cannot) be produced due to the presence (absence) of the ${\eta }_c(2S){\eta }_c(2S)$ channel. Although the pole positions are case-dependent, the relation between the peak structure in the $J/\psi J/\psi$ invariant mass distribution and the dip structure in the $J/\psi {\psi }^{\prime }$ invariant mass distribution around $7.2\text{gev}$ is unambiguous. We suggest experimentalists to detailed scan both the $J/\psi J/\psi$ and the $J/\psi {\psi }^{\prime }$ invariant mass distributions, especially around $7.2\text{gev}$ to probe the nature of the third fully charmed state.

    hep-phSci.Bull.(2023)·27 citations
17. 17*

    Bubble nucleation and gravitational wave from holography

    Yidian Chen🇨🇳 · Danning Li🇨🇳 · Mei Huang🇨🇳

    We investigate the bounce solution in the holographic QCD and electroweak models with first-order phase transition. The strength parameter $\alpha$, inverse duration time $\beta /H$, and bubble wall velocity $v_w$ in the gravitational wave power spectra are calculated by holographic bounce solution. In contrast to the results of field theory, we find the parameter $\alpha$ is about $\mathcal{O}(1)$ and $\beta /H$ is about $10^4$, which imply that the phase transition is fast and strong. The critical, nucleation and percolation temperatures of the phase transition are close to each other in the holographic model. In addition, the velocity $v_w$ is found to be less than the sound speed of the plasma $c_s=1/\sqrt{3}$, which corresponds to the deflagration scenario. For QCD phase transition, the gravitational wave power spectrum can reach $10^{-13}-10^{-14}$ around the peak frequency of 0.01 Hz, which can be detected by BBO and Ultimate-DECIGO. For electroweak phase transition, the gravitational wave power spectrum can reach $10^{-12}-10^{-16}$ around the peak frequency $1-10$ Hz. Moreover, the primordial black hole is not favorable for formation due to the large parameter $\beta /H$ and small velocity $v_w$.

    hep-phJHEP(2023)·15 citations
18. 18*

    Deciphering Colour Building Blocks of Massive Multiparton Amplitudes at 4-loops and beyond

    Neelima Agarwal · Sourav Pal🇮🇳 · Aditya Srivastav🇮🇳 · Anurag Tripathi🇮🇳

    The soft function in non-abelian gauge theories exponentiate, and their logarithms can be organised in terms of the collections of Feynman diagrams called Cwebs. The colour factors that appear in the logarithm are controlled by the web mixing matrices. Direct construction of the diagonal blocks of Cwebs using the new concepts of Normal ordering, basis Cweb and Fused-Web was recently carried out in~\cite{Agarwal:2022wyk}. In this article we establish correspondence between the boomerang webs introduced in ~\cite{Gardi:2021gzz} and non-boomerang Cwebs. We use this correspondence together with Uniqueness theorem and Fused web formalism introduced in ~\cite{Agarwal:2022wyk} to obtain the diagonal blocks of four general classes of Cwebs to all orders in perturbation theory which also cover all the four loop Boomerang Cwebs connecting four Wilson lines. We also fully construct the mixing matrix of a special Cweb to all orders in perturbation theory.

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

    Quark-antiquark states of the lightest scalar mesons within the Nambu-Jona-Lasinio model with flavor-dependent coupling constants

    Fabio L. Braghin🇧🇷

    The quark antiquark components of the U(3) lightest scalar meson nonet are investigated by considering the Nambu-Jona-Lasinio model with flavor-dependent coupling constants that were derived by considering (non-perturbative) gluon exchange.The strange quark effective mass ($M_s^{\ast }$) is varied such that the strangeness content of these scalar mesons can be analyzed further. The neutral states $S_0$, $S_8$ and $S_3$, are adopted as the most relevant quark-antiquark components respectively of the $\sigma (500)$, $f_0(980)$ and $A_0^0(980)$ mesons. As a result, the mass hierarchy between states $S_0$ and $S_8$, and $K_0^{\ast }(700)-A_0(980)$ mesons, can be respectively inverted and corrected for quite low values of the strange quark constituent mass. Besides that, for some particular values of $M_s^{\ast }$, the masses of $\sigma (500)$ and $f_0(980)$ can also be obtained by considering the mixing coupling constant $G_{08}$. However, the masses of all the nine mesons are not described simultaneously in a self-consistent procedure and this goes along with the need of non-quark-antiquark states to completely describe their masses. A neutral-meson mixing matrix is defined and the leading mixing angle is found by fitting a correct value of the $\sigma (500)$-$f_0(980)$ mass difference. Two different estimates for the strengths of the mixings $A_0^0\to f_0$ and $f_0\to A_0^0$ are proposed, leading to somewhat different behaviors. Firstly, by assuming leading transitions to intermediary flavor eigenstates and secondly by considering a dynamical evolution. Results may be in good agreement with experimental values from BESS-III depending on the value of the strange quark effective mass.

    hep-phnucl-thJ.Phys.G(2023)·13 citations
20. 20*

    NNLO jet production in neutral and charged current polarized deep inelastic scattering

    Ignacio Borsa🇦🇷 · Daniel de Florian🇦🇷 · Iván Pedron🇦🇷

    We perform the calculation of the fully differential single-jet production in longitudinally polarized deep inelastic scattering (DIS) at the next-to-next-to-leading order (NNLO) accuracy, featuring both neutral current and charged current processes. The computation is done with the projection-to-Born method (P2B), using the next-to-leading order (NLO) dijet calculation and the NNLO DIS structure functions as its main ingredients. We also analyze its phenomenological consequences in the kinematics of the future Electron-Ion Collider (EIC).

    hep-phPRD(2023)·16 citations
21. 21*

    Probing displaced top quark signature at the LHC Run 3

    Jeremy Andrea🇫🇷 · Daniel Bloch🇫🇷 · Eric Conte🇫🇷 · Douja Darej🇫🇷 · Robin Ducrocq🇫🇷 · Emery Nibigira🇺🇸

    In the context of prospective studies for searches of new physics at the LHC Run 3, this paper investigates the relevance of using top quarks produced from new long-lived particles, and detected in the tracker volume of the ATLAS and CMS experiments. Such a signature, referred to as displaced top quarks, leads to final states containing displaced vertices and a high multiplicity of displaced jets and tracks, thanks to the top quark decays. Therefore, it is a possible powerful tool for searching for new long-lived particles. Three simplified models based on supersymmetry are explicitly designed for the study of this signature. They differ according to the nature of the long-lived heavy particle which produces at least one top quark: electrically neutral or charged, coloured or non-coloured long-lived particle. For each model, a wide region of parameter space, consistent with a reasonable number of displaced top quarks decaying in a typical tracker volume has been probed. From this study, promising benchmarks are defined and experimental guidelines are suggested.

    hep-phEPJC(2023)·1 citation
22. 22*

    Higgs-dilaton model revisited: can dilaton act as QCD axion?

    Aleksandr I. Belokon🇷🇺 · Anna Tokareva🇬🇧

    The Standard Model Lagrangian has an approximate scale symmetry in the high-energy limit. This observation can be included in the fundamental principle of the ultimate theory of Nature as the requirement of the exact quantum scale invariance. In this setup, all low-energy particle phenomenology can be obtained as a result of the spontaneous breaking of scale symmetry leading to the presence of the extra massless scalar field -- the dilaton. We explore the scenario in which this field is capable of solving the strong CP-problem in QCD in a similar way as in QCD axion models. The dilaton, playing the role of the axion, is coupled to the QCD sector and acquires a mass term due to non-perturbative breaking of scale symmetry. We show that the dilaton can form dark matter after the low-scale inflation. As a proof of concept, we construct a model of Higgs-driven inflation consistently realising the axion-like dilaton dark matter production compatible with the CMB data.

    hep-phgr-qchep-thPRD(2023)·5 citations
23. 23*

    Aspects of Inflation and Cosmology in Non-Minimally Coupled and $R^2$ Palatini Gravity

    Kit Lloyd-Stubbs🇬🇧

    This thesis presents research exploring aspects of inflation and cosmology in the context of inflation models in which an inflaton is non-minimally coupled to the Ricci scalar, or is considered in conjunction with a term quadratic in the Ricci scalar. We consider a ${\varphi }^2$ Palatini inflation model in $R^2$ gravity and investigate whether this model can overcome some of the problems of the original ${\varphi }^2$ chaotic inflation model. We investigate the compatibility of this model with the observed CMB when treated as an effective theory of inflation in quantum gravity by examining the constraints on the model parameters arising due to Planck-suppressed potential corrections and reheating. Additionally, we consider two possible reheating channels and assess their viability in relation to the constraints on the size of the coupling to the $R^2$ term. We present an application of the Affleck-Dine mechanism, in which quadratic $B$-violating potential terms generate the asymmetry, with a complex inflaton as the Affleck-Dine field. We derive the $B$ asymmetry generated in the inflaton condensate analytically and numerically. We use the present-day asymmetry to constrain the size of the $B$-violating mass term and derive an upper bound on the inflaton mass in order for the Affleck-Dine dynamics to be compatible with non-minimally coupled inflation in the metric and Palatini formalisms. We demonstrate the existence of a new class of inflatonic Q-balls in a non-minimally coupled Palatini inflation model, through an analytical derivation of the Q-ball equation and numerical confirmation of the existence of solutions, and derive a range of the inflaton mass squared within which the model can inflate and produce Q-balls. We derive analytical estimates of the properties of these Q-balls, explore the effects of curvature, and discuss observational signatures of the model.

    hep-phastro-ph.COgr-qchep-th0 citations
24. 24*

    How relevant are top loops in VBS at the LHC?

    Carlos Quezada-Calonge🇪🇸 · Antonio Dobado🇪🇸 · Juan José Sanz-Cillero🇪🇸

    We present the contributions to the imaginary part of the $W^{+}{W}^{-}$ elastic scattering from top and bottom quark one-loop diagrams. The computation is performed within the context of HEFT, where we compare them with the boson-loop corrections. We argue that the often neglected (top and bottom) fermion contributions may in fact be relevant.

    hep-phNucl.Part.Phys.Proc.(2023)·3 citations
25. 25*

    New solutions in supergravity: A phenomenological study at the LHC

    Robin Ducrocq🇫🇷

    Supersymmetry and supergravity extend the standard model by introducing a new symmetry between fermions and bosons. Experimental data imply that supergravity must be broken. Among several mechanisms of supersymmetry breaking, gravity mediated supersymmetry breaking is central in this thesis. These mechanisms have the main feature to generate the so-called soft SUSY breaking terms. Recently, new solutions have been identified, leading to the usual soft breaking terms together with additional hard breaking terms. These new solutions are characterized by a new singlet chiral superfield with a non-standard behaviour. Along the line of these new solutions, two models with two singlet fields were identified: one leading to hard breaking terms called S2MSSM and one with only soft breaking terms called N2MSSM. In the S2MSSM, we study the effects of the hard breaking terms on the Higgs boson mass through radiative corrections. A comparison between the N2MSSM and the NMSSM through the fine-tuning of the electroweak scale is investigated. We also perform an analysis of a long-lived stop squark signature at the LHC in the MSSM with Gauge Mediated Supersymmetry Breaking.

    hep-phhep-th1 citation
26. 26*

    Phenomenological and cosmological implications of a scotogenic three-loop neutrino mass model

    Asmaa Abada🇫🇷 · Nicolás Bernal🇦🇪 · Antonio E. Cárcamo Hernández🇨🇱 · Sergey Kovalenko🇨🇱 · Téssio B. de Melo🇨🇱 · Takashi Toma🇯🇵

    We propose a scotogenic model for generating neutrino masses through a three-loop seesaw. It is a minimally extended inert doublet model with a spontaneously broken global symmetry $U(1{)}^{\prime }$ and a preserved ${\mathbb{Z}}_2$ symmetry. The three-loop suppression allows the new particles to have masses at the TeV scale without fine-tuning the Yukawa couplings. The model leads to a rich phenomenology while satisfying all the current constraints imposed by neutrinoless double-beta decay, charged-lepton flavor violation, and electroweak precision observables. The relatively large Yukawa couplings lead to sizable rates for charged lepton flavor violation processes, well within future experimental reach. The model could also successfully explain the $W$ mass anomaly and provides viable fermionic or scalar dark matter candidates.

    hep-phJHEP(2023)·13 citations
27. 27*

    Lectures on the string landscape and the Swampland

    Nathan Benjamin Agmon🇺🇸 · Alek Bedroya🇺🇸 · Monica Jinwoo Kang🇺🇸 · Cumrun Vafa🇺🇸

    We provide an overview of the string landscape and the Swampland program. Our review of the string landscape covers the worldsheet and spacetime perspectives, including vacua and string dualities. We then review and motivate the Swampland program from the lessons learned from the string landscape. These lecture notes are aimed to be self-contained and thus can serve as a starting point for researchers interested in exploring these ideas. These notes are an expanded version of two courses "The String Landscape and the Swampland" taught by C.~Vafa at Harvard University in 2018 with a focus on the landscape, written by M.~J.~Kang with additional material from N.~B.~Agmon, and in 2022 with a focus on the Swampland, written by A.~Bedroya.

    ↳ hep-thhep-ph287 citations
28. 28*

    Parametric Resonances in Axionic Cosmic Strings

    Jose J. Blanco-Pillado🇪🇸 · Daniel Jiménez-Aguilar🇪🇸 · Jose M. Queiruga🇪🇸 · Jon Urrestilla🇪🇸

    In this letter we uncover a new parametric resonance of axionic cosmic strings. This process is triggered by the presence on the string of internal mode excitations that resonantly amplify the amplitude of transverse displacements of the string. We study this process by running numerical simulations that demonstrate the existence of this phenomenon in a $(3+1)$ dimensional lattice field theory and compare the results with the analytic expectations for the effective Lagrangian of the amplitude of these modes and their interactions. Finally, we also analyze the massless and massive radiation produced by these excited strings and comment on its relevance for the interpretation of the results of current numerical simulations of axionic cosmic string networks.

    ↳ hep-thastro-ph.COgr-qchep-phJCAP(2023)·12 citations
29. 29*

    Hybrid stars within the framework of the Sigma-Omega-Rho model combined with the MIT and NJL models

    Reza Karimi🇮🇷 · H. R. Moshfegh🇮🇷

    In this paper, we investigate the structure of hybrid stars consisting of hadrons (neutrons, protons, sigmas, lambdas), leptons (electrons, muons), and quarks (up, down, strange). We use a relativistic mean-field (RMF) model namely the Sigma-omega-rho model for the hadronic phase and the MIT bag model as well as the NJL model for the quark phase. In addition, Maxwell and Gibbs conditions are employed to investigate the hadron-Quark phase transition. Finally, by obtaining the mass-radius relation, $M(M_{sun})⩽2.07$ is predicted for such hybrid stars.

    ↳ nucl-thastro-ph.HEhep-phNPA(2023)·5 citations
30. 30*

    The Boltzmann equation and equilibrium thermodynamics in Lorentz-violating theories

    Robertus Potting🇵🇹

    In this work we adapt the foundations of relativistic kinetic theory and the Boltzmann equation to particles with Lorentz-violating dispersion relations. The latter are taken to be those associated to two commonly considered sets of coefficients in the minimal Standard-Model Extension. We treat both the cases of classical (Maxwell-Boltzmann) and quantum (Fermi-Dirac and Bose-Einstein) statistics. It is shown that with the appropriate definition of the entropy current, Boltzmann's H-theorem continues to hold. We derive the equilibrium solutions and then identify the Lorentz-violating effects for various thermodynamic variables, as well as for Bose-Einstein condensation. Finally, a scenario with non-elastic collisions between multiple species of particles corresponding to chemical or nuclear reactions is considered.

    ↳ cond-mat.stat-mechhep-phEur.Phys.J.Plus(2023)·1 citation
31. 31*

    Precision cosmology with primordial GW backgrounds in presence of astrophysical foregrounds

    Davide Racco🇺🇸 · Davide Poletti🇮🇹

    The era of Gravitational-Wave (GW) astronomy will grant the detection of the astrophysical GW background from unresolved mergers of binary black holes, and the prospect of probing the presence of primordial GW backgrounds. In particular, the low-frequency tail of the GW spectrum for causally-generated primordial signals (like a phase transition) offers an excellent opportunity to measure unambiguously cosmological parameters as the equation of state of the universe, or free-streaming particles at epochs well before recombination. We discuss whether this programme is jeopardised by the uncertainties on the astrophysical GW foregrounds that coexist with a primordial background. We detail the motivated assumptions under which the astrophysical foregrounds can be assumed to be known in shape, and only uncertain in their normalisation. In this case, the sensitivity to a primordial signal can be computed by a simple and numerically agile procedure, where the optimal filter function subtracts the components of the astrophysical foreground that are close in spectral shape to the signal. We show that the degradation of the sensitivity to the signal in presence of astrophysical foregrounds is limited to a factor of a few, and only around the frequencies where the signal is closer to the foregrounds. Our results highlight the importance of modelling the contributions of eccentric or intermediate-mass black hole binaries to the GW background, to consolidate the prospects to perform precision cosmology with primordial GW backgrounds.

    ↳ astro-ph.COgr-qchep-phJCAP(2023)·16 citations
32. 32*

    Effective Field Theory for Compact Binary Dynamics

    Walter D. Goldberger🇺🇸

    I review the effective field theory (EFT) description of gravitating compact objects. The focus is on kinematic regimes where gravity is perturbative, in particular the adiabatic inspiral phase relevant to gravitational wave detection. For such configurations, there is a hierarchy of length scales which all play a role in the dynamics, ranging from the gravitational radius, to the size of the objects, to their typical orbital separation, and finally the wavelength of the radiation emitted by the system. To disentangle these scales, and to achieve manifest power counting in the expansion parameter, it is necessary to construct a tower of EFTs of gravity, each coupled to distinct line defect localized degrees of freedom. I describe the relevant effective theories at each scale as well as the matching between these theories across each physical threshold. While the main applications of these methods are to classical dynamics, quantum gravity effects, e.g. Hawking graviton exchange, can be systematically incorporated if the momentum transfers are small compared to the Planck mass.

    ↳ hep-thgr-qchep-ph41 citations
33. 33*

    A Search for Coincident Neutrino Emission from Fast Radio Bursts with Seven Years of IceCube Cascade Events

    R. Abbasi · M. Ackermann · J. Adams · N. Aggarwal · J. A. Aguilar · M. Ahlers · J.M. Alameddine · A. A. Alves Jr. · N. M. Amin · K. Andeen · T. Anderson · G. Anton and 375 other authors

    This paper presents the results of a search for neutrinos that are spatially and temporally coincident with 22 unique, non-repeating Fast Radio Bursts (FRBs) and one repeating FRB (FRB121102). FRBs are a rapidly growing class of Galactic and extragalactic astrophysical objects that are considered a potential source of high-energy neutrinos. The IceCube Neutrino Observatory's previous FRB analyses have solely used track events. This search utilizes seven years of IceCube's cascade events which are statistically independent of the track events. This event selection allows probing of a longer range of extended timescales due to the low background rate. No statistically significant clustering of neutrinos was observed. Upper limits are set on the time-integrated neutrino flux emitted by FRBs for a range of extended time-windows.

    ↳ astro-ph.HEhep-phApJ(2023)·14 citations
34. 34*

    The $\eta \to {\gamma }^{\ast }{\gamma }^{\ast }$ transition form factor and the hadronic light-by-light $\eta$-pole contribution to the muon $g-2$ from lattice QCD

    Constantia Alexandrou🇨🇾 · Simone Bacchio🇨🇾 · Sebastian Burri🇨🇭 · Jacob Finkenrath🇨🇾 · Andrew Gasbarro🇨🇭 · Kyriakos Hadjiyiannakou🇨🇾 · Karl Jansen🇩🇪 · Gurtej Kanwar🇨🇭 · Bartosz Kostrzewa🇩🇪 · Konstantin Ottnad🇩🇪 · Marcus Petschlies🇩🇪 · Ferenc Pittler🇨🇾 · Carsten Urbach🇩🇪 · Urs Wenger🇨🇭

    We calculate the double-virtual $\eta \to {\gamma }^{\ast }{\gamma }^{\ast }$ transition form factor ${\mathcal{F}}_{\eta \to {\gamma }^{\ast }{\gamma }^{\ast }}(q_1^2,q_2^2)$ from first principles using a lattice QCD simulation with $N_f=2+1+1$ quark flavors at the physical pion mass and at one lattice spacing and volume. The kinematic range covered by our calculation is complementary to the one accessible from experiment and is relevant for the $\eta$-pole contribution to the hadronic light-by-light scattering in the anomalous magnetic moment $a_{\mu }=(g-2)/2$ of the muon. From the form factor calculation we extract the partial decay width $\Gamma (\eta \to \gamma \gamma )=323(85{)}_{\text{stat}}(22{)}_{\text{syst}}$ eV and the slope parameter $b_{\eta }=1.19(36{)}_{\text{stat}}(16{)}_{\text{syst}}$ GeV${}^{-2}$. For the $\eta$-pole contribution to $a_{\mu }$ we obtain $a_{\mu }^{\eta -\text{pole}}=13.2(5.2{)}_{\text{stat}}(1.3{)}_{\text{syst}}\cdot 10^{-11}$.

    ↳ hep-lathep-phPRD(2023)·39 citations
35. 35*

    The V-QCD baryon : numerical solution and baryon spectrum

    M. Järvinen🇰🇷 · E. Kiritsis🇫🇷 · F. Nitti🇫🇷 · E. Préau🇫🇷

    The single baryon solution of V-QCD is numerically computed. The spectrum of spin and isospin modes is also computed by quantizing the light fluctuations around the baryon. It is shown that there is a partial restoration of chiral symmetry at the baryon center.

    ↳ hep-thhep-lathep-phnucl-thJHEP(2023)·19 citations
36. 36*

    Path Integral for Mixed Tunneling, Polychronic Tunneling and Quantum Gravity

    Yutaro Shoji🇮🇱

    Quantum tunneling in a many-body system is much more non-trivial than that in a one-body system. The most characteristic phenomenon is the mixed tunneling, which has been studied in many fields for decades. For instance, let us consider a system where there are two coupled particles and only one of them feels a potential barrier. Quantum tunneling of such a system is not described by either Euclidean or Lorentzian time evolution and the exponent of the WKB wave function becomes complex. Recently, a similar phenomenon, polychronic tunneling, has been proposed in quantum gravity, which enhances the decay rate of a meta-stable vacuum by many orders of magnitude. In this paper, we present path integral formalism that is applicable to such systems. The formalism can be directly extended to quantum gravity and has some implications on the problem of time in quantum gravity. We also discuss a possible relation to the conventional path integral.

    ↳ hep-thhep-phquant-ph1 citation
37. 37*

    Imaging Topological Solitons: the Microstructure Behind the Shadow

    Pierre Heidmann🇺🇸 · Ibrahima Bah🇺🇸 · Emanuele Berti🇺🇸

    We study photon geodesics in topological solitons that have the same asymptotic properties as Schwarzschild black holes. These are coherent states in string theory corresponding to pure deformations of spacetime through the dynamics of compact extra dimensions. We compare these solutions with Schwarzschild black holes by computing null geodesics, deriving Lyapunov exponents, and imaging their geometries as seen by a distant observer. We show that topological solitons are remarkably similar to black holes in apparent size and scattering properties, while being smooth and horizonless. Incoming photons experience very high redshift, inducing phenomenological horizon-like behaviors from the point of view of photon scattering. Thus, they provide a compelling case for real-world gravitational solitons and topological alternatives to black holes from string theory.

    ↳ gr-qchep-phhep-thPRD(2023)·33 citations
38. 38*

    Investigating the effect of Milky Way dwarf spheroidal galaxies extension on dark matter searches with Fermi-LAT data

    Mattia Di Mauro🇮🇹 · Martin Stref🇫🇷 · Francesca Calore🇫🇷

    Satellite galaxies of the Milky Way with high mass-to-light ratios and little baryon content, i.e. dwarf spheroidal galaxies (dSphs), are among the most promising targets to detect or constrain the nature of dark matter (DM) through its final annihilation products into high-energy photons. Previously, the assumption that DM emission from dSphs is point-like has been used to set strong constraints on DM candidates using data from the Fermi Large Area Telescope (LAT). However, due to their high DM densities and proximity, dSphs actually have sufficient angular extension to be detected by the Fermi-LAT. Here, we assess, for the first time, the impact of accounting for angular extension in the search for gamma-ray DM signals towards known dSphs with Fermi-LAT. We show that, depending on the dSph under consideration, limits on the DM cross section can be weakened by up to a factor of 2-2.5, while the impact on the stacked, i.e. combined, limits is at most 1.5-1.8 depending on the annihilation channel. This result is of relevance when comparing dSphs limits to other multi-messenger DM constraints and for testing the DM interpretation of anomalous "excesses".

    ↳ astro-ph.HEhep-phPRD(2022)·33 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.