Thu·Dec 23, 2021Thursday·December 23, 2021

1. 01*

   Ultralight Millicharged Dark Matter via Misalignment

   Zachary Bogorad🇺🇸 · Natalia Toro🇺🇸

   We explore the cosmology and phenomenology of millicharged and millicharge-like dark matter with masses from 1 eV to 10 keV and charges of $10^{-18}$ to $10^{-14}$. Dark matter in this mass range cannot be thermally produced, but can arise from non-thermal mechanisms. We propose a concrete model employing a spontaneously broken approximate global symmetry, in which millicharged dark matter is produced via the misalignment mechanism. We show that this production mechanism is cosmologically consistent and compatible with the observed dark matter abundance. This model can be implemented using either fundamental scalars or hidden-sector quarks, and coupled either to the Standard Model photon or to a hidden photon. We then consider the phenomenology of light millicharged dark matter, regardless of its cosmological origin, and determine the parameter space consistent with existing experiments and observations. A significant part of the new parameter space we consider may be accessible in the near future through direct deflection experiments, measurements of the cosmic microwave background blackbody spectrum, and future constraints on plasma instabilities due to dark matter self-interaction.

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

   Bottomonium suppression and elliptic flow in heavy-ion collisions

   Michael Strickland🇺🇸

   In this proceedings contribution I review recent progress concerning the suppression of bottomonium production in the quark-gluon plasma. Making use of open quantum system methods applied to potential non-relativistic quantum chromodynamics one can show that the dynamics of heavy-quarkonium bound states satisfying the scale hierarchy 1/a_0 >> pi T ~ m_D >> E obey a Lindblad equation whose solution provides the quantum evolution of the heavy-quarkonium reduced density matrix. To solve the resulting Lindblad equation we use a quantum trajectories algorithm which allows one to include all possible angular momentum states of the quark-antiquark probe in a scalable manner. We solve the Lindblad equation using a tuned 3+1D dissipative hydrodynamics code for the background temperature evolution. We then consider a large number of Monte-Carlo sampled bottomonium trajectories embedded in this background. This allows us to extract the centrality- and p_T-dependence of the nuclear suppression factor R_AA[Upsilon] and elliptic flow v_2[Upsilon]. We find good agreement between our model predictions and available sqrt(s_NN) = 5.02 TeV Pb-Pb collision experimental data from the ALICE, ATLAS, and CMS collaborations.

   hep-phnucl-thRev.Mex.Fis.Suppl.(2022)·2 citations
3. 03*

   Experimental constraints on the properties of $P_c$ states

   T.J. Burns🇬🇧 · E.S. Swanson🇺🇸

   Using new experimental data on photoproduction and ${\Lambda }_b^0$ decays, we derive constraints on the properties of the LHCb $P_c$ states. We conclude that $P_c(4312)$, $P_c(4380)$ and $P_c(4440)$ can be described as ${\Sigma }_c\bar{D}$, ${\Sigma }_c^{\ast }\bar{D}$ and ${\Sigma }_c{\bar{D}}^{\ast }$ molecules, but that $P_c(4457)$ does not fit into the same picture. Based on the apparent absence of additional partner states, and the striking disparity between ${\Lambda }_c^{+}{\bar{D}}^0$ and ${\Lambda }_c^{+}{\bar{D}}^{\ast 0}$ decays, we conclude that $P_c(4440)$ has $3/2^{-}$ quantum numbers. Using heavy-quark symmetry we predict large experimental signals for $P_c$ states in ${\eta }_{c}p{K}^{-}$, ${\Lambda }_c^{+}{\bar{D}}^{\ast 0}{K}^{-}$, and ${\Sigma }_c^{(\ast )}\bar{D}{K}^{-}$. We also argue that current experimental data on photoproduction is almost at the level of sensitivity required to observe $P_c$ states.

   hep-phhep-exEPJA(2022)·25 citations
4. 04*

   Technically natural Higgs boson from Planck scale

   Martin Rosenlyst🇬🇧

   We propose UV complete (Partially) Composite Higgs models with compositeness scale up to the Planck scale assisted by a novel mechanism. This mechanism is based on softly breaking a global ${\mathbb{Z}}_2$ symmetry by technically natural small vacuum misalignment, dynamically triggering the electroweak symmetry breaking and Standard Model fermion mass generation. This mechanism can be present in various models based on vacuum misalignment. For concreteness, we demonstrate it in a minimal partially composite two-Higgs scheme, where the Higgs is a mixture of a composite and an elementary state, transforming odd under an ${\mathbb{Z}}_2$ symmetry. For this concrete model example, all the dimensionful fundamental parameters are approximately $\mathcal{O}(10^{18})$ GeV. We study the vacuum stability of this model by investigating the renormalization group running of the quartic coupling of the Higgs. Furthermore, the parameter space can already be searched by gravitational waves from a confinement-induced phase transition. Finally, the mass and mixing of the neutrinos may be naturally generated via loops of a second Higgs doublet, transforming even under the ${\mathbb{Z}}_2$ symmetry, which may be challenged by lattice calculations and a more accurate measurement of the top mass.

   hep-phhep-thPRD(2022)·15 citations
5. 05*

   Production of axion-like particles via vector boson fusion at future electron-positron colliders

   Chong-Xing Yue🇨🇳 · Hua-Ying Zhang🇨🇳 · Han Wang🇨🇳

   One kind of particularly interesting pseudoscalar particles, called axion-like particles (ALPs), have rich physical phenomenology at high- and low-energy collider experiments. After discussing most of single production channels of ALP at electron-positron colliders, we investigate the possibility of detecting this kind of new particles through the W${}^{+}$W${}^{-}$ fusion process e${}^{+}$e${}^{-}$ $\to$ ${\overline{\nu }}_e$${\nu }_{e}a$ $(\to \gamma \gamma )$ at the CLIC. The 3$\sigma$ and 5$\sigma$ bounds on the ALP parameter space at the three energy stages of the CLIC are obtained. We find that the bounds given by the CLIC are complementary to the existing experiments exclusion regions.

   hep-phEPJC(2022)·27 citations
6. 06*

   Parton distribution function uncertainties in theoretical predictions for far-forward tau neutrinos at the Large Hadron Collider

   Weidong Bai🇨🇳 · Milind Diwan🇺🇸 · Maria Vittoria Garzelli🇩🇪 · Yu Seon Jeong🇰🇷 · Fnu Karan Kumar🇺🇸 · Mary Hall Reno🇺🇸

   New experiments to measure neutrinos in the far-forward region at the Large Hadron Collider (LHC) are under design or already in preparation. Two of them, FASER$\nu$ and SND@LHC, are expected to be active during Run 3 and have the potential to detect neutrinos that come from high-energy collisions in one of the LHC interaction points, extracted along the direction tangent to the beam line. Tau neutrinos and antineutrinos come predominantly from $D_s^{\pm }$ production in $pp$ collisions, followed by the leptonic decay of these mesons. Neutrino pseudorapidities in the range of $\eta >6.9$ and $\eta >8.9$ are relevant to these future experiments. At such pseudorapidities at high energies, theoretical predictions for the flux of tau neutrinos rely on parton distribution functions (PDFs) in a combination of very small and large parton$-x$ values. We evaluate PDF uncertainties in a next-to-leading order (NLO) QCD calculation of the flux of ${\nu }_{\tau }$ + ${\bar{\nu }}_{\tau }$ produced by $D_s^{\pm }$ decay in the far forward region at the LHC. The theoretical uncertainty associated with the 40 PDF sets of the PROSA19 group amounts to $\pm (20-30)$\% for the (${\nu }_{\tau }$ + ${\bar{\nu }}_{\tau }$) number of charged-current (CC) events. Scale uncertainties are much larger, resulting in a range of CC event predictions from $\sim 70\%$ lower to $\sim 90\%$ higher than the central prediction. A comparison of the predictions with those obtained using as input the central PDFs from the 3-flavour NLO PDF sets of the CT14, ABMP16 and NNPDF3.1 collaborations show that far-forward neutrino energy distributions vary by as much as a factor of $\sim 2-4$ relative to the PROSA19 predictions at TeV neutrino energies. The Forward Physics Facility in the high luminosity LHC era will provide data capable of constraining NLO QCD evaluations with these PDF sets.

   hep-phhep-exnucl-exnucl-thJHEP(2022)·36 citations
7. 07*

   SMEFTs living on the edge: determining the UV theories from positivity and extremality

   Cen Zhang🇨🇳

   We study the "inverse problem" in the context of the Standard Model Effective Field Theory (SMEFT): how and to what extend can one reconstruct the UV theory, given the measured values of the operator coefficients in the IR? The main obstacle of this problem is the degeneracies in the space of coefficients: a given SMEFT truncated at a finite dimension can be mapped to infinitely many UV theories. We discuss these degeneracies at the dimension-8 level, and show that positivity bounds play a crucial role in the inverse problem. In particular, the degeneracies either vanish or become significantly limited for SMEFTs that live on or close to the positivity bounds. The UV particles of these SMEFTs, and their properties such as spin, charge, other quantum numbers, and interactions with the SM particles, can often be uniquely determined, assuming dimension-8 coefficients are measured. The allowed region for SMEFTs, which forms a convex cone, can be systematically constructed by enumerating its generators. We show that a geometric notion, extremality, conveniently connects the positivity problem with the inverse problem. We discuss the implications of a SMEFT living on an extremal ray, on a $k$-face, and on the vertex of the positive cone. We also show that the information of the dimension-8 coefficients can be used to set exclusion limits on all individual UV states that interact with the SM, independent of specific model assumptions. Our results indicate that the dimension-8 operators encode much more information about the UV than one would naively expect, which can be used to reverse engineer the UV physics from the SMEFT.

   hep-phhep-exhep-thJHEP(2022)·54 citations
8. 08*

   Consequences of $b\to s{\mu }^{+}{\mu }^{-}$ anomalies on $B\to K^{(\ast )}\nu \bar{\nu }$, $B_s\to (\eta ,{\eta }^{\prime })\nu \bar{\nu }$ and $B_s\to \varphi \nu \bar{\nu }$ decay observables

   N Rajeev🇮🇳 · Rupak Dutta🇮🇳

   The long persistent discrepancies in $b\to s\ell \ell$ quark level transitions continue to be the ideal platform for an indirect search of new physics that lies beyond the SM. The measurements of $R_K$, $R_{K^{\ast }}$, $P_5^{\prime }$, $\mathcal{B}(B_s\to \varphi {\mu }^{+}{\mu }^{-})$ and $\mathcal{B}(B_s\to {\mu }^{+}{\mu }^{-})$ persistently deviate from the standard model expectations. Similarly, the new tests of lepton flavor universality performed using the isospin partners such as $B^0\to K_S^0\ell \ell$ and $B^{+}\to K^{+\ast }\ell \ell$ exhibit the same pattern of deviation in $R_{K_S^0}$ and $R_{K^{\ast +}}$ with the existing results. Motivated by these anomalies we search for the patterns of new physics in the family of flavor changing neutral decays with neutral leptons in the final state undergoing $b\to s\nu \bar{\nu }$ quark level transitions. There are close relations between $b\to s\ell \ell$ and $b\to s\nu \bar{\nu }$ transitions not only in standard model but also in various beyond the standard model scenarios. For beyond the standard model physics under the $\mathrm{S}{\mathrm{U}}_{\mathrm{L}}(2)$ gauge symmetry one can relate the left handed charged leptons to the neutrinos. Moreover, there are several advantages of studying $b\to s\nu \bar{\nu }$ transitions over $b\to s\ell \ell$ as they are free from various hadronic uncertainties beyond the form factors such as the non-factorizable corrections and photonic penguin contributions. Hence, we explore the consequences of $b\to s{\mu }^{+}{\mu }^{-}$ anomalies on $B\to K^{(\ast )}\nu \bar{\nu }$, $B_s\to (\eta ,{\eta }^{\prime })\nu \bar{\nu }$ and $B_s\to \varphi \nu \bar{\nu }$ decay observables in SMEFT platform within various 1D and 2D new physics scenarios.

   hep-phPRD(2022)·20 citations
9. 09*

   Road map through the desert with scalars

   Ubaldo Cavazos Olivas🇵🇱 · Kamila Kowalska🇵🇱 · Dinesh Kumar🇮🇳

   In the context of the gauge coupling unification, we present a comprehensive analysis of the extensions of the Standard Model with vector-like fermions and scalars. We find 145 models that satisfy the unification condition, which are distinguishable by the number of new particles in the spectrum and by their transformation properties under the gauge symmetry group of the Standard Model. For all models we derive lower bounds on the exotic fermion and scalar masses, stemming from the measurement of the strong gauge coupling scale dependence, from the heavy stable charged particle searches, and from the electroweak precision tests. We also discuss the potential of testing the unification scenarios at the future 100 TeV collider and in the proton decay experiments. We show that many models can already be excluded based on the current data, while many others will be entirely probed in the coming years.

   hep-phJHEP(2022)·6 citations
10. 10*

    Effects of weak magnetic field and finite chemical potential on the transport of charge and heat in hot QCD matter

    Shubhalaxmi Rath🇮🇳 · Sadhana Dash🇮🇳

    We have studied the effects of weak magnetic field and finite chemical potential on the transport of charge and heat in hot QCD matter by estimating their respective response functions, such as the electrical conductivity (${\sigma }_{\mathrm{el}}$), the Hall conductivity (${\sigma }_{\mathrm{H}}$), the thermal conductivity (${\kappa }_0$) and the Hall-type thermal conductivity (${\kappa }_1$). The expressions of charge and heat transport coefficients are obtained by solving the relativistic Boltzmann transport equation in the relaxation time approximation at weak magnetic field and finite chemical potential. The interactions among partons are incorporated through their thermal masses. We have observed that ${\sigma }_{\mathrm{el}}$ and ${\kappa }_0$ decrease and ${\sigma }_{\mathrm{H}}$ and ${\kappa }_1$ increase with the magnetic field in the weak magnetic field regime. On the other hand, the presence of a finite chemical potential increases these transport coefficients. The effects of weak magnetic field and finite chemical potential on aforesaid transport coefficients are found to be more conspicuous at low temperatures, whereas at high temperatures, they have only a mild dependence on magnetic field and chemical potential. We have found that the presence of finite chemical potential further extends the lifetime of the magnetic field. Furthermore, we have explored the effects of weak magnetic field and finite chemical potential on the Knudsen number, the elliptic flow coefficient and the Wiedemann-Franz law.

    hep-phhep-thnucl-thEPJA(2023)·21 citations
11. 11*

    Can sub-GeV dark matter coherently scatter on the electrons in the Atom?

    Ji-Heng Guo🇨🇳 · Yu-Xuan Sun🇨🇳 · Wenyu Wang🇨🇳 · Ke-Yun Wu🇨🇳

    A novel detection of sub-GeV dark matter is proposed in the paper. The electron cloud is boosted by the dark matter and emits an electron when it is dragged back by the heavy nucleus, namely the coherent scattering of the electron cloud of the atom. The survey in the X-ray diffraction shows that the atomic form factors are much more complicate than the naive consideration. The results of the relativistic Hartree-Fock(RHF) method give non-trivial shapes of the atoms. The detailed calculation of the recoil of the electron cloud, the kinetics, the fiducial cross section and the corresponding calculation of detection rate are given analytically. The numerical results show that the limits of the RHF form factors are much stringent than the recoil of a single electron, almost 4 orders stronger, and also gives tight limitations comparing to the Migdal effect below about several hundred MeV. The physical picture and the corresponding results are promising and need further explorations.

    hep-phastro-ph.COphysics.atom-phCommun.Theor.Phys.(2023)·6 citations
12. 12*

    Imaging nuclear modifications on parton distributions with triple-differential dijet cross sections in proton-nucleus collisions

    Shuwan Shen🇨🇳 · Peng Ru🇨🇳 · Ben-Wei Zhang🇨🇳

    Dijet production in proton-nucleus ($p$A) collisions at the LHC provides invaluable information on the underlying parton distributions in nuclei, especially the gluon distributions. Triple-differential dijet cross sections enable a well-controlled kinematic scan (over momentum fraction $x$ and probing scale $Q^2$) of the nuclear parton distribution functions (nPDFs), i.e., $f_i^{\text{A}}(x,Q^2)$. In this work, we study several types of triple-differential cross sections for dijet production in proton-proton ($pp$) and proton-lead ($p$Pb) collisions at the LHC, to next-to-leading order within the framework of perturbative quantum chromodynamics (pQCD). Four sets of nPDF parametrizations, EPPS16, nCTEQ15, TUJU19, and nIMParton16 are employed in the calculations for $p$Pb collisions. We show that the observable nuclear modification factor $R_{p\text{Pb}}$ of such cross sections can serve as a nice image of the nuclear modifications on parton distributions, quantified by the ratio $r_i^{\text{A}}(x,Q^2)=f_i^{\text{A,proton}}(x,Q^2)/f_i^{\text{proton}}(x,Q^2)$. Considerable differences among the $R_{p\text{Pb}}$ predicted by the four nPDF sets can be observed and intuitively understood. Future measurements of such observables are expected to not only constrain the nPDF parametrizations, but also help confirm various nuclear effects, e.g., shadowing, anti-shadowing, EMC, and Fermi motion in different regions of $x$ and their variations with probing scale $Q^2$.

    hep-phnucl-thPRD(2022)·5 citations
13. 13*

    Scalar Triplet Leptogenesis with a CP violating phase

    Sreerupa Chongdar🇮🇳 · Sasmita Mishra🇮🇳

    We study baryogenesis through leptogenesis via decay of triplet scalars embedded in the Standard Model. We consider two triplets scenario where the vacuum expectation value developed by one of the triplets is complex. The coupling of the triplet Higgs with the Standard Model leptons and Higgs scalar allows two decay channels, with branching ratios $B_L$ and $B_{\varphi }$, respectively. It is known that the hierarchy between the two branching ratios ($B_L\gg B_{\varphi }$ or $B_{\varphi }\gg B_L$), is sensitive to the generation of adequate CP violation and efficiency of leptogenesis. Working in a hierarchical limit of branching ratios and requiring adequate CP violation, we find the mass of the lightest triplet can be as low as $1\times 10^{10}$ GeV. In the temperature regime $\left[10^9,10^{12}\right]$ GeV, flavor effects, especially two-flavor effects become important in the study of leptogenesis. In two-flavored regime we study flavor effects in leptogenesis. It is observed that adequate baryon asymmetry can not be obtained for purely flavored leptogenesis, which corresponds to the hierarchical branching ratios, $B_L\gg B_{\varphi }$. But the hierarchy in the other way $B_{\varphi }\gg B_L$ still allows successful baryogenesis through leptogenesis. The phase of the complex vacuum expectation value of the triplet scalar is constrained by requiring non-zero CP violation. Considering the mass scale of triplet scalars as TeV scale, we also study resonant leptogenesis in the light of TeV scale physics.

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

    Models with two Higgs doublets and a light pseudoscalar:a portal to dark matter and the possible $(\mathbf{g}-2{)}_{\mu }$ excess

    Giorgio Arcadi🇮🇹 · Abdelhak Djouadi🇪🇸 · Farinaldo Queiroz🇧🇷

    In the context of a two-Higgs doublet model, supplemented by an additional light pseudoscalar Higgs boson and a stable isosinglet fermion, we consider the possibility of addressing simultaneously the discrepancy from the standard expectation of the anomalous magnetic moment of the muon recently measured at Fermilab and the longstanding problem of the dark matter in the universe which can be accounted for by a thermal weakly interacting massive particle. We show that it is indeed possible, for a range of masses and couplings of the new light pseudoscalar and the fermionic states, to explain at the same time the two features while satisfying all other constraints from astroparticle physics and collider searches, including the constraints from flavor physics.

    hep-phPLB(2022)·12 citations
15. 15*

    NNLO nuclear parton distribution functions with electroweak-boson production data from the LHC

    Ilkka Helenius🇫🇮 · Marina Walt🇩🇪 · Werner Vogelsang🇩🇪

    We present new sets of nuclear parton distribution functions (nPDFs) at next-to-leading order and next-to-next-to-leading order in perturbative QCD. Our analyses are based on deeply inelastic scattering data with charged-lepton and neutrino beams on nuclear targets, and experimental data from measurements of $W^{\pm },Z$ boson production in p+Pb collisions at the LHC. In addition, a set of proton baseline PDFs is fitted within the same framework and with the same theoretical assumptions. The results of our global QCD analysis are compared to existing nPDF sets and to the previous nPDF set TUJU19 which was based on DIS data only. Our work is performed using an open-source tool, xFitter, and the required extensions of the code are discussed as well. We find good agreement with the data included in the fit and a lower value for ${\chi }^2/N_{\mathrm{dp}}$ when performing the fit at next-to-next-to-leading order. We apply the resulting nuclear PDFs to electroweak-boson production in Pb+Pb collisions at the LHC and compare the results to the most recent data from ATLAS and CMS.

    hep-phPRD(2022)·68 citations
16. 16*

    A 96 GeV Higgs Boson in the 2HDM plus Singlet

    S. Heinemeyer🇪🇸 · C. Li🇩🇪 · F. Lika🇩🇪 · G. Moortgat-Pick🇩🇪 · S. Paasch🇩🇪

    We discuss a $\sim 3\sigma$ signal (local) in the light Higgs-boson search in the diphoton decay mode at $\sim 96$ GeV as reported by CMS, together with a $\sim 2\sigma$ excess (local) in the $b\bar{b}$ final state at LEP in the same mass range. We interpret this possible signal as a Higgs boson in the 2 Higgs Doublet Model type II with an additional Higgs singlet, which can be either complex (2HDMS) or real (N2HDM). We find that the lightest CP-even Higgs boson of the two models can equally yield a perfect fit to both excesses simultaneously, while the second lightest state is in full agreement with the Higgs-boson measurements at $125$ GeV, and the full Higgs-boson sector is in agreement with all Higgs exclusion bounds from LEP, the Tevatron and the LHC as well as other theoretical and experimental constraints. We derive bounds on the 2HDMS and N2HDM Higgs sectors from a fit to both excesses and describe how this signal can be further analyzed at future $e^{+}{e}^{-}$ colliders, such as the ILC. We analyze in detail the anticipated precision of the coupling measurements of the $96$ GeV Higgs boson at the ILC. We find that these Higgs-boson measurements at the LHC and the ILC cannot distinguish between the two Higgs-sector realizations.

    hep-phPRD(2022)·103 citations
17. 17*

    New physics in $s\to d$ semileptonic transitions: rare hyperon vs. kaon decays

    Li-Sheng Geng🇨🇳 · Jorge Martin Camalich🇪🇸 · Rui-Xiang Shi🇨🇳

    We investigate the potential of rare hyperon decays to probe the short distance structure in the $s\to d\nu \bar{\nu }$ and $s\to d{\ell }^{+}{\ell }^{-}$ transitions. Hyperon decays into neutrinos ($B_1\to B_2\nu \bar{\nu }$) can be reliably predicted by using form factors determined in baryon chiral perturbation theory. Their decay rates are sensitive to different short-distance operators, as compared to their kaon counterparts, and the corresponding branching fractions are in the range of $10^{-14}\sim 10^{-13}$ in the standard model. In the context of the low-energy effective theory, we find that the anticipated BESIII measurements of the $B_1\to B_2\nu \bar{\nu }$ decays would lead to constraints on new physics in the purely axial vector $\bar{d}{\gamma }_{\mu }{\gamma }_{5}s$ current that are stronger than the present limits from their kaon siblings $K\to \pi \pi \nu \bar{\nu }$. On the other hand, although hyperon decays into charged leptons are dominated by long-distance hadronic contributions, angular observable such as the leptonic forward-backward asymmetry is sensitive to the interference between long- and short-distance contributions. We discuss the sensitivity to new physics of a potential measurement of this observable in comparison with observables in the kaon decays $K_L\to {\mu }^{+}{\mu }^{-}$ and $K^{+}\to {\pi }^{+}{\mu }^{+}{\mu }^{-}$. We conclude that the current kaon bounds are a few orders of magnitude better than those that could be obtained from ${\Sigma }^{+}\to p{\mu }^{+}{\mu }^{-}$ except for two scenarios with new physics in the $(\bar{d}{\gamma }^{\mu }s)(\bar{\ell }{\gamma }_{\mu }{\gamma }_5\ell )$ and $(\bar{d}{\gamma }^{\mu }{\gamma }_{5}s)(\bar{\ell }{\gamma }_{\mu }\ell )$ currents. Finally, we point out that the loop effects from renormalization group evolution are important in this context, when relating the low-energy effective field theory to new physics models in the UV.

    hep-phhep-exJHEP(2022)·20 citations
18. 18*

    Addendum to "Invisible Higgs decay width versus dark matter direct detection cross section in Higgs portal dark matter models"

    Seungwon Baek🇰🇷 · Pyungwon Ko🇰🇷 · Wan-Il Park🇰🇷

    This article is an addendum to Ref.~\cite{Baek:2014jga}. Here, we discuss the invisible Higgs decay width ${\Gamma }_h^{\mathrm{inv}}$ in the Higgs portal vector dark matter (VDM) model in the limit $m_V\to 0^{+}$. In the effective field theory (EFT) approach where the VDM mass is attributed to the Stückelberg mechanism, $({\Gamma }_h^{\mathrm{inv}}{)}_{\mathrm{EFT}}$ is divergent, which is unphysical and puzzling. On the other hand $({\Gamma }_h^{\mathrm{inv}}{)}_{\mathrm{UV}}$ becomes finite in a UV completion, where the VDM mass is generated by the dark Higgs mechanism. Then we can take the limit $m_V\to 0^{+}$ by taking either {\it (i)} the dark gauge coupling $g_X\to 0^{+}$ with a fixed dark Higgs vacuum expectation value $v_{\Phi }$, or {\it (ii)} $v_{\Phi }\to 0^{+}$ with a fixed $g_X$. Such a difference in the behavior of ${\Gamma }_h^{\mathrm{inv}}$ in the massless VDM limit demonstrates another limitation of EFT for the Higgs portal VDM, and the importance of gauge-invariant and renormalizable models for the Higgs portal VDM.

    hep-phhep-exPRD(2022)·8 citations
19. 19*

    Indirect detection of long-lived particles in a rich dark sector with a dark vector portal

    Krzysztof Jodłowski🇵🇱 · Leszek Roszkowski🇵🇱 · Sebastian Trojanowski🇵🇱

    Simplified models of light new physics provide a convenient benchmark for experimental searches for new physics signatures, including dark matter (DM). However, additional detection modes can arise in less simplified and more realistic scenarios where new degrees of freedom are invoked. In this study, we introduce a non-minimal model based on a popular dark photon portal to DM where the mediator mass is obtained by interactions with the dark Higgs boson which acts as a long-lived particle. We further add to this scenario a new heavy DM species secluded from the Standard Model. In this model, which involves light and heavy particles in the dark sector, we find some new interesting phenomenological features that lead to complementary probes in intensity frontier searches for light long-lived particles, indirect detection searches for dark matter, and cosmic microwave background surveys. We also find possible non-local effects in the DM indirect detection searches that could significantly affect the usual detection strategies.

    hep-phastro-ph.COPRD(2023)·4 citations
20. 20*

    Testing the molecular nature of $\varphi (2170)$

    A. Martínez Torres🇧🇷 · Brenda B. Malabarba🇧🇷 · Xiu-Lei Ren🇩🇪 · K. P. Khemchandani🇧🇷

    In this talk we show our recent results on the decay widths of $\varphi (2170)$ to final states formed by an anti-Kaon and a Kaonic resonance, in particular, $K(1460)$, $K_1(1270)$ and $K_1(1400)$, considering a molecular description for $\varphi (2170)$. Branching fraction ratios are obtained and compared with the recent results found by the BESIII collaboration, finding compatible results.

    hep-phnucl-thRev.Mex.Fis.Suppl.(2022)·0 citations
21. 21*

    Gravitational Wave Imprints of Left-Right Symmetric Model with Minimal Higgs Sector

    Lukáš Gráf🇩🇪 · Sudip Jana🇩🇪 · Ajay Kaladharan🇺🇸 · Shaikh Saad🇨🇭

    We study the gravitational wave imprints of left-right symmetric model equipped with universal seesaw mechanism allowing for the natural generation of hierarchical masses of the Standard Model fermions. The scalar sector of this model is the minimal one, consisting of only two Higgs doublets. Following the construction of the full thermal potential for this model, we perform a scan of the entire parameter space and identify the region in which the cosmic phase transition associated with the left-right symmetry breaking gives gravitational wave signals detectable by a variety of planned space-based interferometers. Then we also discuss the relevant collider implications of this beyond the Standard Model scenario.

    hep-phastro-ph.COhep-exJCAP(2022)·24 citations
22. 22*

    Searching for new physics from SMEFT and leptoquarks at the P2 experiment

    Ingolf Bischer🇩🇪 · P. S. Bhupal Dev🇺🇸 · Werner Rodejohann🇩🇪 · Xun-Jie Xu🇨🇳 · Yongchao Zhang🇨🇳

    The P2 experiment aims at high-precision measurements of the parity-violating asymmetry in elastic electron-proton and electron-${}^{12}$C scatterings with longitudinally polarized electrons. We discuss here the sensitivity of P2 to leptoquarks, which within the P2 energy range can be described in the language of Standard Model Effective Field Theory (SMEFT). We give the expected P2 limits on the SMEFT operators and on the leptoquark parameters, which will test energy scales up to 15 TeV. In many cases those limits exceed current constraints from LHC and atomic parity violation (APV) experiments. We also demonstrate that degeneracies of different SMEFT operators can partially be resolved by use of APV experiments and different targets (protons and ${}^{12}$C) at P2. Moreover, we show that P2 could confirm or resolve potential tensions between the theoretical and experimental determinations of the weak charge of ${}^{133}$Cs.

    hep-phhep-exPRD(2022)·5 citations
23. 23*

    NLO electroweak and QCD corrections to the production of a photon with three charged lepton plus missing energy at the LHC

    Huanfeng Cheng🇺🇸 · Doreen Wackeroth🇺🇸

    Electroweak (EW) triboson production processes with at least one heavy gauge boson are of increasing interest at the Large Hadron Collider (LHC) as direct precision probes of one of the least-tested sectors of the Standard Model (SM), the quartic couplings of the EW gauge bosons. These processes therefore offer promising opportunities for searches for indirect signals of Beyond-the-SM (BSM) physics. In this paper, we present results for fiducial cross sections at next-to-leading-order (NLO) EW and NLO QCD to $pp\to e^{+}{\nu }_e{\mu }^{+}{\mu }^{-}\gamma$ at the 13 TeV LHC. This signature includes the triboson production process $pp\to W^{+}Z\gamma$ with leptonic decays, $W^{+}\to e^{+}{\nu }_e$ and $Z\to {\mu }^{+}{\mu }^{-}$. The computation is based on the complete set of leading-order (LO) contributions of $\mathcal{O}({\alpha }^5)$ and on NLO EW and NLO QCD cross sections of $\mathcal{O}({\alpha }^6)$ and $\mathcal{O}({\alpha }^5{\alpha }_{\text{s}})$, respectively, and thus off-shell effects, spin correlations and non-resonance contributions are fully taken into account. We construct a Monte Carlo framework which provides total and differential cross sections for a chosen set of basic analysis cuts. We find that while NLO EW corrections enhance the fiducial LO total cross section by only $1\%$, they can significantly change some distributions in certain kinematic regions. For example, the relative NLO EW corrections to the muon transverse momentum distribution at 500 GeV amounts to $-20\%$. To illustrate how missing NLO EW corrections could masquerade as BSM physics, we show examples for the impact of dimension-8 operators in the SM Effective Field Theory framework on selected kinematic distributions.

    hep-phPRD(2022)·7 citations
24. 24*

    $Z_2$ Non-Restoration and Composite Higgs: Singlet-Assisted Baryogenesis w/o Topological Defects

    Andrei Angelescu🇩🇪 · Florian Goertz🇩🇪 · Aika Tada🇩🇪

    Simple scalar-singlet extensions of the Standard Model with a (spontaneously broken) $Z_2$ symmetry allow for a strong first order electroweak phase transition, as sought in order to realize electroweak baryogenesis. However they generically also lead to the emergence of phenomenologically problematic domain walls. Here we present a framework with a real scalar singlet that features a different thermal history that avoids this problem by never restoring the $Z_2$ symmetry in the early universe. This is accomplished by considering $D>4$ operators that emerge on general grounds, understanding the model as the low energy tail of a more complete theory, like for example in composite Higgs scenarios. Sticking to the latter framework, we present a concrete $SO(6)/SO(5)$ composite realization of the idea. To this end, we additionally provide a complete classification of the structure of the Higgs potential (and the Yukawa couplings) in $SO(6)/SO(5)$ models with fermions in the $1,6,15$ or $20^{\prime }$ of $SO(6)$.

    hep-phhep-thJHEP(2022)·6 citations
25. 25*

    LHC Signatures of $\tau$-Flavoured Vector Leptoquarks

    Jordan Bernigaud🇩🇪 · Monika Blanke🇩🇪 · Ivo de Medeiros Varzielas🇵🇹 · Jim Talbert🇩🇰 · José Zurita🇪🇸

    We consider the phenomenological signatures of Simplified Models of Flavourful Leptoquarks, whose Beyond-the-Standard Model (SM) couplings to fermion generations occur via textures that are well motivated from a broad class of ultraviolet flavour models (which we briefly review). We place particular emphasis on the study of the vector leptoquark ${\Delta }_{\mu }$ with assignments $\left(3,1,2/3\right)$ under the SM's gauge symmetry, $SU(3{)}_C\times SU(2{)}_L\times U(1{)}_Y$, which has the tantalising possibility of explaining both ${\mathcal{R}}_{K^{(\star )}}$ and ${\mathcal{R}}_{D^{(\star )}}$ anomalies. Upon performing global likelihood scans of the leptoquark's coupling parameter space, focusing in particular on models with tree-level couplings to a single charged lepton species, we then provide confidence intervals and benchmark points preferred by low(er)-energy flavour data. Finally, we use these constraints to further evaluate the (promising) Large Hadron Collider (LHC) detection prospects of pairs of $\tau$-flavoured ${\Delta }_{\mu }$, through their distinct (a)symmetric decay channels. Namely, we consider direct third-generation leptoquark and jets plus missing-energy searches at the LHC, which we find to be complementary. Depending on the simplified model under consideration, the direct searches constrain the ${\Delta }_{\mu }$ mass up to 1500-1770 GeV when the branching fraction of ${\Delta }_{\mu }$ is entirely to third-generation quarks (but are significantly reduced with decreased branching ratios to the third generation), whereas the missing-energy searches constrain the mass up to 1150-1700 GeV while being largely insensitive to the third-generation branching fraction.

    hep-phJHEP(2022)·15 citations
26. 26*

    Gearing up for the next generation of LFV experiments, via on-shell methods

    Joan Elias Miro🇮🇹 · Clara Fernandez🇪🇸 · Mehmet Asim Gumus🇮🇹 · Alex Pomarol🇪🇸

    Lepton Flavor Violating (LFV) observables such as $\mu \to e\gamma$, $\mu \to 3e$ and $\mu N\to eN$ are among the best probes for new physics at the TeV scale. In the near future the bounds on these observables will improve by many orders of magnitude. In this work we use the SM EFT to understand the impact of these measurements. The precision reach is such that the interpretation of the bounds requires an analysis of the dimension-six operator mixing up to the two-loop level. Using on-shell amplitude techniques, which make transparent many selection rules, we classify and calculate the different operator mixing chains. At the leading order, on-shell techniques allow to calculate anomalous dimensions of SM EFT operators from the product of tree-level amplitudes, even for two-loop renormalization group mixings. We illustrate the importance of our EFT approach in models with extra vector-like fermions.

    hep-phhep-thJHEP(2022)·26 citations
27. 27*

    Vacuum (meta-)stability in the $\mu \nu$SSM

    Thomas Biekötter🇩🇪 · Sven Heinemeyer🇪🇸 · Georg Weiglein🇩🇪

    We perform an analysis of the vacuum stability of the neutral scalar potential of the $\mu$-from-$\nu$ Supersymmetric Standard Model ($\mu \nu$SSM). As an example scenario, we discuss the alignment-without-decoupling limit of the $\mu \nu$SSM, for which the required conditions on the Higgs sector are derived. We demonstrate that in this limit large parts of the parameter space feature unphysical minima that are deeper than the electroweak minimum. In order to estimate the lifetime of the electroweak vacuum, we calculate the rates for the tunneling process into each unphysical minimum. We find that in many cases the resulting lifetime is longer than the age of the universe, such that the considered parameter region is not excluded. On the other hand, we also find parameter regions in which the electroweak vacuum is short-lived. We investigate how the different regions of stability are related to the presence of light right-handed sneutrinos. Accordingly, a vacuum stability analysis that accurately takes into account the possibility of long-lived metastable vacua is crucial for a reliable assessment of the phenomenological viability of the parameter space of the $\mu \nu$SSM and its resulting phenomenology at the (HL)-LHC.

    hep-phEPJC(2022)·9 citations
28. 28*

    Top-pair production at the LHC with MiNNLO${}_{\mathrm{PS}}$

    Javier Mazzitelli🇩🇪 · Pier Francesco Monni🇨🇭 · Paolo Nason🇮🇹 · Emanuele Re🇫🇷 · Marius Wiesemann🇩🇪 · Giulia Zanderighi🇩🇪

    We consider the production of a pair of heavy quarks and illustrate the derivation of the MiNNLO method to match next-to-next-to-leading order calculations with parton showers (NNLO+PS) for this class of processes. As a first application, we construct an event generator for the fully differential simulation of hadronic top-quark pair production at NNLO+PS and discuss all details of its implementation in a parton shower Monte Carlo framework. We present new phenomenological results for the Large Hadron Collider obtained by including the tree-level decays of the top quarks, while accounting for spin-correlation effects. A comprehensive comparison to LHC measurements shows an excellent description of experimental data across multiple hadronic and leptonic particle-level observables. The computer code is available for download within the POWHEG-BOX.

    hep-phhep-exJHEP(2022)·97 citations
29. 29*

    Antiproton production with a fixed target and search for superheavy particles at the LHC

    A. B. Kurepin (1)🇷🇺 · N. A. Kurepin (2)🇷🇺 · K. A. Skazytkin (2) ((1) Institute for Nuclear Research, Moscow, Russia (2) Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Moscow, Russia)🇷🇺

    A proposal for an experiment to measure the cross section of antiproton production in a proton-nuclear collision in a kinematically forbidden region for nucleon-nucleon interaction on a fixed LHC target is considered. It is shown that this process can be separated from the kinematically allowed production process using the existing detectors of the ALICE facility at a proton energy of 7 TeV with a fixed nuclear target. Assuming the scale dependence of the cross section, the data obtained can be used to estimate the subthreshold cross section for the production of superheavy particles with a mass of several tens of TeV in the LHC lead nucleus beam.

    hep-phhep-exJ.Mod.Phys.(2022)·0 citations
30. 30*

    Dense and Hot QCD at Strong Coupling

    Tuna Demircik🇰🇷 · Christian Ecker🇩🇪 · Matti Järvinen🇰🇷

    We present a novel framework for the equation of state of dense and hot Quantum Chromodynamics (QCD), which focuses on the region of the phase diagram relevant for neutron star mergers and core-collapse supernovae. The model combines predictions from the gauge/gravity duality with input from lattice field theory, QCD perturbation theory, chiral effective theory and statistical modeling. It is therefore, by construction, in good agreement with theoretical constraints both at low and high densities and temperatures. The main ingredients of our setup are the non-perturbative V-QCD model based on the gauge/gravity duality, a van der Waals model for nucleon liquid, and the DD2 version of the Hempel-Schaffner-Bielich statistical model of nuclear matter. By consistently combining these models, we also obtain a description for the nuclear to quark matter phase transition and its critical endpoint. The parameter dependence of the model is represented by three (soft, intermediate and stiff) variants of the equation of state, all of which agree with observational constraints from neutron stars and their mergers. We discuss resulting constraints for the equation of state, predictions for neutron stars and the location of the critical point.

    hep-phastro-ph.HEgr-qchep-th+1PRX(2022)·66 citations
31. 31*

    A Faster Growth of Perturbations in an Early Matter Dominated Epoch: Primordial Black Holes and Gravitational Waves

    Subinoy Das🇮🇳 · Anshuman Maharana🇮🇳 · Francesco Muia🇬🇧

    We present a scenario for fast growth of cosmological perturbations; $\delta (t)\sim a(t{)}^s$, $a(t)$ being the scale factor, with $s>10$ for the numerical examples reported in this article. The basic ingredients of the scenario are an early matter dominated era and the dark fermion which experiences a scalar mediated force during the epoch. Both of these arise in string/supergravity models. The fast growth occurs for sub-horizon density perturbations of the dark fermion. The fast growth has a rich set of phenomenological implications. We outline implications for the formation of primordial black holes and the production of gravitational waves. Primordial black holes in the sub-lunar mass range (which are ideal dark matter candidates) can be produced. Gravitational waves can be produced in a wide range of frequencies due to second order scalar perturbations and due to evaporation and merger of primordial black holes.

    ↳ astro-ph.COhep-phhep-thMNRAS(2022)·11 citations
32. 32*

    Quintessential inflation and nonlinear effects of the tachyonic trap mechanism

    Mindaugas Karčiauskas🇪🇸 · Stanislav Rusak🇪🇸 · Alejandro Saez🇪🇸

    With the help of the tachyonic trapping mechanism one can potentially solve a number of problems affecting quintessential inflation models. In this mechanism we introduce a trapping field with a spontaneous symmetry breaking potential. When the quintessential inflaton passes the critical point, a sudden burst of particle production is able to reheat the Universe and trap the inflaton away from theminimum of its potential. However, self-interactions of the trapping field suppress particle production and reduce the efficiency of this process. We develop a method to compute the magnitude of the suppression and explore the parameter space in which the mechanism can be applied effectively.

    ↳ astro-ph.COhep-phPRD(2022)·10 citations
33. 33*

    Hubble distancing: Focusing on distance measurements in cosmology

    Kylar L. Greene🇺🇸 · Francis-Yan Cyr-Racine🇺🇸

    The Hubble-Lemaitre tension is currently one of the most important questions in cosmology. Most of the focus so far has been on reconciling the Hubble constant value inferred from detailed cosmic microwave background measurement with that from the local distance ladder. This emphasis on one number -- namely $H_0$ -- misses the fact that the tension fundamentally arises from disagreements of distance measurements. To be successful, a proposed cosmological model must accurately fit these distances rather than simply infer a given value of $H_0$. Using the newly developed likelihood package `distanceladder', which integrates the local distance ladder into MontePython, we show that focusing on $H_0$ at the expense of distances can lead to the spurious detection of new physics in models which change late-time cosmology. As such, we encourage the observational cosmology community to make their actual distance measurements broadly available to model builders instead of simply quoting their derived Hubble constant values.

    ↳ astro-ph.COhep-phJCAP(2022)·16 citations
34. 34*

    Search for a light Higgs boson in single-photon decays of ${\rm Y}(1S)$ using ${\rm Y}(2S)\to {\pi }^{+}{\pi }^{-}{\rm Y}(1S)$ tagging method

    Belle Collaboration: S. Jia🇨🇳 · C. P. Shen🇨🇳 · I. Adachi🇯🇵 · H. Aihara🇯🇵 · S. Al Said🇸🇦 · D. M. Asner🇺🇸 · H. Atmacan🇺🇸 · T. Aushev🇷🇺 · R. Ayad🇸🇦 · V. Babu🇩🇪 · P. Behera🇮🇳 · K. Belous🇷🇺 and 200 other authors

    We search for a light Higgs boson ($A^0$) decaying into a ${\tau }^{+}{\tau }^{-}$ or ${\mu }^{+}{\mu }^{-}$ pair in the radiative decays of ${\rm Y}(1S)$. The production of ${\rm Y}(1S)$ mesons is tagged by ${\rm Y}(2S)\to {\pi }^{+}{\pi }^{-}{\rm Y}(1S)$ transitions, using 158 million ${\rm Y}(2S)$ events accumulated with the Belle detector at the KEKB asymmetric energy electron-positron collider. No significant $A^0$ signals in the mass range from the ${\tau }^{+}{\tau }^{-}$ or ${\mu }^{+}{\mu }^{-}$ threshold to 9.2 GeV/$c^2$ are observed. We set the upper limits at 90\% credibility level (C.L.) on the product branching fractions for ${\rm Y}(1S)\to \gamma A^0$ and $A^0\to {\tau }^{+}{\tau }^{-}$ varying from $3.8\times 10^{-6}$ to $1.5\times 10^{-4}$. Our results represent an approximately twofold improvement on the current world best upper limits for the ${\rm Y}(1S)\to \gamma A^0(\to {\tau }^{+}{\tau }^{-})$ production. For $A^0\to {\mu }^{+}{\mu }^{-}$, the upper limits on the product branching fractions for ${\rm Y}(1S)\to \gamma A^0$ and $A^0\to {\mu }^{+}{\mu }^{-}$ are at the same level as the world average limits, and vary from $3.1\times 10^{-7}$ to $1.6\times 10^{-5}$. The upper limits at 90\% C.L. on the Yukawa coupling $f_{{\rm Y}(1S)}$ and mixing angle $\sin {\theta }_{A^0}$ are also given.

    ↳ hep-exhep-phPRL(2022)·17 citations
35. 35*

    Quintessential inflation: A tale of emergent and broken symmetries

    Dario Bettoni🇪🇸 · Javier Rubio🇵🇹

    Quintessential inflation provides a unified description of inflation and dark energy in terms of a single scalar degree of freedom, the cosmon. We present here a comprehensive overview of this appealing paradigm, highlighting its key ingredients and keeping a reasonable and homogeneous level of details. After summarizing the cosmological evolution in a simple canonical case, we discuss how quintessential inflation can be embedded in a more general scalar-tensor formulation and its relation to variable gravity scenarios. Particular emphasis is placed on the role played by symmetries. In particular, we discuss the evolution of the cosmon field in terms of ultraviolet and infrared fixed points potentially appearing in quantum gravity formulations and leading to the emergence of scale invariance in the early and late Universe. The second part of the review is devoted to the exploration of the phenomenological consequences of the paradigm. First, we discuss how direct couplings of the cosmon field to matter may affect neutrinos masses and primordial structure formation. Second, we describe how Ricci-mediated couplings to spectator fields can trigger the spontaneous symmetry breaking of internal symmetries such as, but not limited to, global U(1) or $Z_2$ symmetries, and affect a large variety of physical processes in the early Universe.

    ↳ astro-ph.COgr-qchep-phGalaxies(2022)·58 citations
36. 36*

    Reliability Analysis of the Results of the Known Experiments on Measuring of the Sachs Form Factor Ratio Using the Rosenbluth Technique. Polarization of the Final Proton in the $e\vec{p}\to e\vec{p}$ Elastic Process

    M. V. Galynskii🇧🇾

    A criterion for assessing the reliability of measurements of the Sachs form factor ratio using the Rosenbluth technique is proposed and applied to an analysis of three known experiments (Andivahis1994, Walker1994, Qattan2005) and a recent experiment on the CEBAF accelerator upgraded to 12 GeV at JLab (arXiv:2103.01842 [nucl-ex]). Based on the results of the JLab polarization experiments on measuring the ratio ${\mu }_p{G}_E/G_M$ in the $\vec{e}p\to e\vec{p}$ process, in the kinematics of the SANE Collaboration experiment (2020) on the measurement of double spin asymmetry in the $\vec{e}\vec{p}\to ep$ process numerical calculations are performed for the $Q^2$ dependence of polarization transferred to the proton in the $e\vec{p}\to e\vec{p}$ process when the initial proton at rest is partially polarized along the direction of motion of the detected recoil proton.

    ↳ nucl-exhep-phPhys.Part.Nucl.Lett.(2022)·3 citations
37. 37*

    Introductory Notes on Non-linear Electrodynamics and its Applications

    Dmitri P. Sorokin🇮🇹

    In 1933-1934 Born and Infeld constructed the first non-linear generalization of Maxwell's electrodynamics that turned out to be a remarkable theory in many respects. In 1935 Heisenberg and Euler computed a complete effective action describing non-linear corrections to Maxwell's theory due to quantum electron-positron one-loop effects. Since then, these and a variety of other models of non-linear electrodynamics proposed in the course of decades have been extensively studied and used in a wide range of areas of theoretical physics including string theory, gravity, cosmology and condensed matter (CMT). In these notes I will overview general properties of non-linear electrodynamics and particular models which are distinguished by their symmetries and physical properties, such as a recently discovered unique non-linear modification of Maxwell's electrodynamics which is conformal and duality invariant. I will also sketch how non-linear electromagnetic effects may manifest themselves in physical phenomena (such as vacuum birefringence), in properties of gravitational objects (e.g. charged black holes) and in the evolution of the universe, and can be used, via gravity/CMT holography, for the description of properties of certain conducting and insulating materials.

    ↳ hep-thcond-mat.str-elgr-qchep-ph+1Fortsch.Phys.(2022)·215 citations
38. 38*

    New constraint on Early Dark Energy from Planck and BOSS data using the profile likelihood

    Laura Herold🇩🇪 · Elisa G. M. Ferreira🇯🇵 · Eiichiro Komatsu🇩🇪

    A dark energy-like component in the early universe, known as early dark energy (EDE), is a proposed solution to the Hubble tension. Currently, there is no consensus in the literature as to whether EDE can simultaneously solve the Hubble tension and provide an adequate fit to the data from the cosmic microwave background (CMB) and large-scale structure of the universe. In this work, we deconstruct the current constraints from the Planck CMB and the full-shape clustering data of the Baryon Oscillation Spectroscopic Survey (BOSS) to understand the origin of different conclusions in the literature. We use two different analyses, a grid sampling and a profile likelihood, to investigate whether the current constraints suffer from volume effects upon marginalization and are biased towards some values of the EDE fraction, $f_{\mathrm{EDE}}$. We find that $f_{\mathrm{EDE}}$ allowed by the data strongly depends on the particular choice of the other parameters of the model and that several choices of these parameters prefer larger values of $f_{\mathrm{EDE}}$ than in the Markov Chain Monte Carlo analysis. This suggests that volume effects are the reason behind the disagreement in the literature. Motivated by this, we use a profile likelihood to analyze the EDE model and compute a confidence interval for $f_{\mathrm{EDE}}$, finding $f_{\mathrm{EDE}}=0.072\pm 0.036$ ($68\%$ C.L.). This confidence interval is not subject to volume effects; thus, our approach yields more robust constraints on EDE and provides a powerful tool to understand whether EDE is a possible solution to the Hubble tension.

    ↳ astro-ph.COgr-qchep-phhep-thApJL(2022)·150 citations
39. 39*

    3+1d Boundaries with Gravitational Anomaly of 4+1d Invertible Topological Order for Branch-Independent Bosonic Systems

    Zheyan Wan🇨🇳 · Juven Wang🇺🇸 · Xiao-Gang Wen🇺🇸

    We study bosonic systems on a spacetime lattice defined by path integrals of commuting fields. We introduce branch-independent bosonic (BIB) systems, whose path integral is independent of the branch structure of the spacetime simplicial complex, even for a spacetime with boundaries. In contrast, a generic lattice bosonic (GLB) system's path integral may depend on the branch structure. We find the invertible topological order characterized by the Stiefel-Whitney cocycle (e.g., 4+1d w${}_2$w${}_3$) to be nontrivial for BIB systems, but this topological order and a trivial gapped tensor product state belong to the same phase for GLB systems. The invertible topological orders in GLB systems are not classified by the oriented cobordism. The branch dependence on a lattice may be related to the orthonormal frame of smooth manifolds and the framing anomaly of continuum field theories. The branch structure on a discretized lattice may be related to a frame structure on a smooth manifold that trivializes any Stiefel-Whitney classes. We construct BIB systems to realize the w${}_2$w${}_3$ topological order, and its 3+1d gapped or gapless boundaries. A 3+1d ${\mathbb{Z}}_2$ gauge theory with (1) fermionic ${\mathbb{Z}}_2$ gauge charge particle trivializes w${}_2$ and (2) fermionic ${\mathbb{Z}}_2$ gauge flux line trivializes w${}_3$. In particular, if the flux loop's worldsheet is unorientable, then an orientation-reversal 1d worldline corresponds to a fermion worldline carrying no ${\mathbb{Z}}_2$ gauge charge. Spin and Spin${}^c$ structures trivialize the w${}_2$w${}_3$ global pure gravitational anomaly to zero (which helps to construct 3+1d ${\mathbb{Z}}_2$ and all-fermion U(1) gauge theories), but the Spin${}^h$ and Spin${\times }_{{\mathbb{Z}}_2}$Spin$(n\ge 3)$ structures modify the w${}_2$w${}_3$ into a global mixed gauge-gravitational anomaly, which helps to constrain Grand Unifications (e.g., $n=10,18$) or construct new models.

    ↳ cond-mat.str-elhep-lathep-phhep-th+1PRB(2022)·13 citations
40. 40*

    Slow-roll inflation in Palatini $F(R)$ gravity

    Christian Dioguardi🇪🇪 · Antonio Racioppi🇪🇪 · Eemeli Tomberg🇪🇪

    We study single field slow-roll inflation in the presence of $F(R)$ gravity in the Palatini formulation. In contrast to metric $F(R)$, when rewritten in terms of an auxiliary field and moved to the Einstein frame, Palatini $F(R)$ does not develop a new dynamical degree of freedom. However, it is not possible to solve analytically the constraint equation of the auxiliary field for a general $F(R)$. We propose a method that allows us to circumvent this issue and compute the inflationary observables. We apply this method to test scenarios of the form $F(R)=R+\alpha R^n$ and find that, as in the previously known $n=2$ case, a large $\alpha$ suppresses the tensor-to-scalar ratio $r$. We also find that models with $F(R)$ increasing faster than $R^2$ for large $R$ suffer from numerous problems.

    ↳ gr-qcastro-ph.COhep-phJHEP(2022)·42 citations
41. 41*

    Bound on Quantum Fluctuations in Gravitational Waves from LIGO-Virgo

    Mark P. Hertzberg🇺🇸 · Jacob A. Litterer🇺🇸

    We derive some of the central equations governing quantum fluctuations in gravitational waves, making use of general relativity as a sensible effective quantum theory at large distances. We begin with a review of classical gravitational waves in general relativity, including the energy in each mode. We then form the quantum ground state and coherent state, before then obtaining an explicit class of squeezed states. Since existing gravitational wave detections arise from merging black holes, and since the quantum nature of black holes remains puzzling, one can be open-minded to the possibility that the wave is in an interesting quantum mechanical state, such as a highly squeezed state. We compute the time and space two-point correlation functions for the quantized metric perturbations. We then constrain its amplitude with LIGO-Virgo observations. Using existing LIGO-Virgo data, we place a bound on the (exponential) squeezing parameter of the quantum gravitational wave state of $\zeta <41$.

    ↳ gr-qcastro-ph.COhep-phhep-th+1JCAP(2023)·24 citations
42. 42*

    A Measurement of the Cosmic Expansion Within our Lifetime

    Fulvio Melia🇺🇸

    The most exciting future observation in cosmology will feature a monitoring of the cosmic expansion in real time, unlike anything that has ever been attempted before. This campaign will uncover crucial physical properties of the various constituents in the Universe, and perhaps answer a simpler question concerning whether or not the cosmic expansion is even accelerating. An unambiguous yes/no response to this query will significantly impact cosmology, of course, but also the standard model of particle physics. Here, we discuss -- in a straightforward way -- how to understand the so-called `redshift drift' sought by this campaign, and why its measurement will help us refine the standard-model parameters if the answer is `yes.' A `no' answer, on the other hand, could be more revolutionary, in the sense that it might provide a resolution of several long-standing problems and inconsistencies in our current cosmological models. An outcome of zero redshift drift, for example, would obviate the need for a cosmological constant and render inflation completely redundant.

    ↳ gr-qcastro-ph.COhep-phEur.J.Phys.·7 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.