Tue·Oct 26, 2021Tuesday·October 26, 2021

1. 01*

   The energy dependence of the multiplicity moments at the LHC

   G. R. Germano🇧🇷 · F. S. Navarra🇧🇷

   In this work, from the experimental data we evaluate the first C-moments of the multiplicity distributions recently measured in proton-proton collisions at the LHC and compare them with the predictions of two models: the Kharzeev-Levin model and the Bialas-Praszalowicz model. We divide the data into three sets according to their phase space coverage: I: $p_T>100$ MeV and $|\eta |<0.5$; II: $p_T>100$ MeV and $|\eta |<2.4$ and II: $p_T>500$ MeV and $|\eta |<2.4$. The mean multiplicity grows with the energy according to a power law and the power is different for each set. The $C_n$ moments grow continuously with the energy, slowly in set I and faster in the other sets. Except for KL in set II, both models reproduce the main features of the data. The negative binomial parameter $k$ decreases continuously with the energy and there is no sign of change in this behavior.

   hep-phPRD(2022)·14 citations
2. 02*

   NNLO QCD corrections to $B$-meson mixing

   Vladyslav Shtabovenko🇩🇪

   We report on the calculation of next-to-next-to-leading order (NNLO) QCD corrections to the width difference $\Delta {\Gamma }_s$ in the neutral $B$-meson mixing process $B_s^0-{\bar{B}}_s^0$. These contributions represent an important step in the task of reducing the existing large perturbative errors in the theory prediction for $\Delta {\Gamma }_s$ and approaching the current experimental uncertainties. We explain the theoretical framework employed in this computation and point out important subtleties in the treatment of evanescent operators and the renormalization. Part of our new results is already available in the literature, while the remaining pieces are expected to be published later this year.

   hep-phPoS(2022)·0 citations
3. 03*

   Towards two- and three-loop QCD corrections to the width difference in $B_s-{\bar{B}}_s$ mixing

   Vladyslav Shtabovenko🇩🇪

   In this work we address the issue of large perturbative uncertainties in the theory prediction for $\Delta {\Gamma }_s$, the width difference in the $B_s^0-{\bar{B}}_s^0$ mixing process. To this aim we complete important steps towards the full analytic result for the previously unknown Wilson coefficients from the matching between $|\Delta B|=1$ and $|\Delta B|=2$ effective Hamiltonians at next-to-next-leading order (NNLO) in the strong coupling constant. We provide a thorough discussion of technical and conceptual difficulties behind this computation and give an outlook regarding the availability of the new NNLO theory prediction for $\Delta {\Gamma }_s$.

   hep-phSciPost Phys.Proc.(2022)·0 citations
4. 04*

   The doubly charmed strange tetraquark

   Marek Karliner🇮🇱 · Jonathan L. Rosner🇺🇸

   The LHCb experiment at CERN has discovered a doubly charmed isoscalar tetraquark $T_{cc}$ with the quantum numbers of $cc\bar{u}\bar{d}$ and mass of about 3875 MeV/$c^2$, decaying to $D^0{D}^0{\pi }^{+}$ through the intermediate channel $D^{\ast +}{D}^0$. We present a study of its strange companions with the quantum numbers of $cc\bar{q}\bar{s}$, where $q=u,d$ and isospin violation is neglected.

   hep-phPRD(2022)·23 citations
5. 05*

   QCD Sum Rules at High Temperature

   Thors Hans Hansson🇸🇪 · Ismail Zahed🇺🇸

   We generalize the sum rule approach to investigate the nonperturbative structure of QCD at high temperature. Salient features of the QCD phase above $T_c$ are discussed, and included in the form of power corrections or condensate insertions, in an operator product expansion of gauge invariant correlators. It is shown that for a plausible choice of condensates, QCD at high temperature exhibits color singlet excitations in the vector channels, as opposed to merely screened quarks and gluons.

   hep-phhep-lathep-thnucl-th1 citation
6. 06*

   Quark-Antiquark Effective Potential in Symplectic Quantum Mechanics

   R. R. Luz · Caroline S. R. Costa · G. X. A. Petronilo · A. E. Santana · R. G. G. Amorim · R. A. S. Paiva

   In this paper, we study within the structure of Symplectic Quantum Mechanics a bi-dimensional non-relativistic strong interaction system which represent the bound state of heavy quark-antiquark, where we consider a Cornell potential which consists of Coulomb-type plus linear potentials. First, we solve the Schrödinger equation in the phase space with the linear potential. The solution (ground state) is obtained and analyzed by means of the Wigner function related to Airy function for the $c\overline{c}$ meson. In the second case, to treat the Schrödinger-like equation in the phase space, a procedure based on the Bohlin transformation is presented and applied to the Cornell potential. In this case, the system is separated into two parts, one analogous to the oscillator and the other we treat using perturbation method. Then, we quantized the Hamiltonian with the aid of stars operators in the phase space representation so that we can determine through the algebraic method the eigenfunctions of the undisturbed Hamiltonian (oscillator solution), and the other part of the Hamiltonian was the perturbation method. The eigenfunctions found (undisturbed plus disturbed) are associated with the Wigner function via Weyl product using the representation theory of Galilei group in the phase space. The Wigner function is analyzed, the non-classicality of ground state and first excited state is studied by the non-classicality indicator or negativity parameter of the Wigner function for this system. In some aspects, we observe that the Wigner function offers an easier way to visualize the non-classic nature of meson system than the wavefunction does.

   hep-phhep-thAdv.High Energy Phys.(2022)·6 citations
7. 07*

   Exploring B-physics anomalies at colliders

   Jorge Alda🇪🇸 · Jaume Guasch🇪🇸 · Siannah Penaranda🇪🇸

   Several experimental measurements of $B$ meson decays, in tension with Standard Model predictions, exhibit large sources of Lepton Flavour Universality violation. We perform an analysis of the effects of the global fits to the Wilson coefficients assuming a model independent effective Hamiltonian approach, by including a proposal of different scenarios to include the New Physics contributions. Both the current fits at the LHC and the ILC projections are considered. We found that for a simultaneous analysis of predictions for the $R_{D^{(\ast )}}$ and $R_{K^{(\ast )}}$ observables, the scenarios with three non-universal Wilson coefficients are favoured.

   hep-phPoS(2022)·3 citations
8. 08*

   A semi-supervised approach to dark matter searches in direct detection data with machine learning

   Juan Herrero-Garcia🇪🇸 · Riley Patrick🇦🇺 · Andre Scaffidi🇮🇹

   The dark matter sector remains completely unknown. It is therefore crucial to keep an open mind regarding its nature and possible interactions. Focusing on the case of Weakly Interacting Massive Particles, in this work we make this general philosophy more concrete by applying modern machine learning techniques to dark matter direct detection. We do this by encoding and decoding the graphical representation of background events in the XENONnT experiment with a convolutional variational autoencoder. We describe a methodology that utilizes the `anomaly score' derived from the reconstruction loss of the convolutional variational autoencoder as well as a pre-trained standard convolutional neural network, in a semi-supervised fashion. Indeed, we observe that optimum results are obtained only when both unsupervised and supervised anomaly scores are considered together. A data set that has a higher proportion of anomaly score is deemed anomalous and deserves further investigation. Contrary to classical analyses, in principle all information about the events is used, preventing unnecessary information loss. Lastly, we demonstrate the reach of learning-focused anomaly detection in this context by comparing results with classical inference, observing that, if tuned properly, these techniques have the potential to outperform likelihood-based methods.

   hep-phJCAP(2022)·18 citations
9. 09*

   MiMeS: Misalignment Mechanism Solver

   Dimitrios Karamitros🇬🇧

   We introduce a C++ header-only library that is used to solve the axion equation of motion, MiMeS. MiMeS makes no assumptions regarding the cosmology and the mass of the axion, which allows the user to consider various cosmological scenarios and axion-like models. MiMeS also includes a convenient python interface that allows the library to be called without writing any code in C++, with minimal overhead.

   hep-phComput.Phys.Commun.(2022)·13 citations
10. 10*

    A simple model to include initial-state and hot-medium effects in the computation of quarkonium nuclear modification factor

    Miguel Ángel Escobedo🇪🇸 · Elena G. Ferreiro🇪🇸

    Quarkonium suppression is one of the more useful observables to obtain information about the hot medium created in ultrarelativistic heavy-ion collisions. In this manuscript, we discuss a simple way to implement both the initial-state effects and the hot-medium evolution, and to compute the quarkonium nuclear modification factor if the survival probability for a bound state at a given energy density is known. Based on the Glauber model, the temperature of the evolving medium and the centrality dependence of the nuclear modification factor will be analysed.

    hep-phnucl-thPRD(2022)·6 citations
11. 11*

    Relativistic kinetic equation for dense gases from quantum field theory

    Jin Hu🇨🇳

    We derive the relativistic kinetic equation and collision kernel for dense gases of spin $0$ particles from quantum field theory based on the Wigner-function formalism. The formalism developed by Degroot can be used as an effective way for density expansion of the kinetic equation. The kinetic equation obtained in the lowest order in density recovers the Boltzmann equation with a nonlocal binary collision term. Keeping this expansion procedure, we derive the triple collision term, which can be seen as a relativistic extension of correspondent works on the transport research about dense gases in the non-relativistic cases. Considering the widespread practicability in different physical systems, the kinetic equation for dense gases we obtain shall be put into good use.

    hep-ph2 citations
12. 12*

    Oscillations in Modified Combinants of Hadronic Multiplicity Distributions

    P. Agarwal🇸🇬 · H. W. Ang🇸🇬 · Z. Ong🇸🇬 · A. H. Chan🇸🇬 · C. H. Oh🇸🇬

    Oscillations in modified combinants ($C_j$s) have been of interest to multiparticle production mechanisms since the 1990s. Recently, there has been a discussion on how these oscillations can be reproduced by compounding a binomial distribution with a negative binomial distribution. In this work, we explore a stochastic branching model based on a simple interaction term $\lambda \overline{\psi }\varphi \psi$ for partons and propose a hadronization scheme to arrive at the final multiplicity distribution. We study the effects that compounding our model with a binomial distribution has on $C_j$s and explore its physical implications. We find that there is a significant difference in the oscillations in $C_j$s between high energy $pp$ and $p\bar{p}$ scattering that our model can reproduce.

    hep-phSciPost Phys.Proc.(2022)·1 citation
13. 13*

    Production of charmed baryon ${\Lambda }_c(2860)$ via low energy antiproton-proton interaction

    Qing-Yong Lin🇨🇳 · Xiang Liu🇨🇳

    In the present work, we study the production problem of the charmed baryon ${\Lambda }_c(2860{)}^{+}$ at $\overline{\text{mbox}P}$ANDA. With the $J^P={\frac{3}{2}}^{+}$ assignment to ${\Lambda }_c(2860{)}^{+}$, an effective Lagrangian approach is adopted to calculate the cross section of $p\bar{p}\to {\Lambda }_c^{-}{\Lambda }_c(2860{)}^{+}$. The Dalitz plot analysis and the $D^{0}p$ invariant mass spectrum distribution are also given for the $p\bar{p}\to {\Lambda }_c^{-}{\Lambda }_c(2860{)}^{+}\to {\Lambda }_c^{-}p{D}^0$ process. The numerical results show that the total cross section may reach up to about 10 $\mu$b. With the designed luminosity of $\overline{\text{mbox}P}$ANDA ($2\times 10^{32}\text{mbox}{cm}^{-2}\text{mbox}{s}^{-1}$), about $10^8$ ${\Lambda }_c(2860)$ events can be expected per day by reconstructing the final $p{D}^0$.

    hep-phhep-exPRD(2022)·4 citations
14. 14*

    Toward establishing the low-lying $P$-wave excited ${\Sigma }_c$ baryon states

    Kai-Lei Wang🇨🇳 · Xian-Hui Zhong🇨🇳

    In this study, by combining the equal spacing rule with recent observations of ${\Omega }_c(X)$ and ${\Xi }_c(X)$ baryons, we predict the spectrum of the low-lying $\lambda$-mode $1P$-wave excited ${\Sigma }_c$ states. Furthermore, their strong decay properties are predicted using the chiral quark model and the nature of ${\Sigma }_c(2800)$ is investigated by analyzing the ${\Lambda }_c\pi$ invariant mass spectrum. The ${\Sigma }_c(2800)$ structure observed in the ${\Lambda }_c\pi$ mass spectrum was found to potentially arise from two overlapping $P$-wave ${\Sigma }_c$ resonances, ${\Sigma }_c(2813)3/2^{-}$ and ${\Sigma }_c(2840)5/2^{-}$. These resonances have similar decay widths of $\Gamma \sim 40$ MeV and predominantly decay into the ${\Lambda }_c\pi$ channel. The ${\Sigma }_c(2755)1/2^{-}$ state is likely to be a very narrow state with a width of $\Gamma \sim 15$ MeV, with its decays almost saturated by the ${\Lambda }_c\pi$ channel. Additionally, evidence of the ${\Sigma }_c(2755){\frac{1}{2}}^{-}$ resonance as a very narrow peak may be seen in the ${\Lambda }_c\pi$ invariant mass spectrum. The other two $P$-wave states, ${\Sigma }_c(2746){\frac{1}{2}}^{-}$ and ${\Sigma }_c(2796){\frac{3}{2}}^{-}$, are relatively narrow states with similar widths of $\Gamma \sim 30$ MeV and predominantly decay into ${\Sigma }_c\pi$ and ${\Sigma }_c^{\ast }\pi$, respectively. We hope our study can provide useful references for discovering these low-lying $P$-wave states in forthcoming experiments.

    hep-phCPC(2022)·14 citations
15. 15*

    Impact of $b\to s\ell \ell$ anomalies on rare charm decays in non-universal $Z^{\prime }$ models

    Ashutosh Kumar Alok🇮🇳 · Neetu Raj Singh Chundawat🇮🇳 · Dinesh Kumar🇮🇳

    In this work, we study the impact of $b\to s\ell \ell$, $B_s-\overline{B_s}$ mixing and neutrino trident measurements on observables in decays induced by $c\to u$ transition in the context of a non-universal $Z^{\prime }$ model which generates $C_9^{\mathrm{NP}}<0$ and $C_9^{\mathrm{NP}}=-C_{10}^{\mathrm{NP}}$ new physics scenarios at the tree level. We inspect the effects on $D^0\to {\pi }^0\nu \bar{\nu }$, $D^{+}\to {\pi }^{+}\nu \bar{\nu }$ and $B_c\to B^{+}\nu \bar{\nu }$ decays which are induced by the quark level transition $c\to u\nu \bar{\nu }$. The fact that the branching ratios of these decays are negligible in the standard model (SM) and the long distance effects are relatively smaller in comparison to their charged dileptons counterparts, they are considered to provide genuine null-tests of SM. Therefore the observation of these modes at the level of current as well as planned experimental sensitivities would imply unambiguous signature of new physics. Using the constraints on $Z^{\prime }$ couplings coming from a combined fit to $b\to s\ell \ell$, $\Delta M_s$ and neutrino trident data, we find that any meaningful enhancement over the SM value is ruled out in the considered framework. The same is true for $D-\bar{D}$ mixing observable $\Delta M_D$ along with $D^0\to {\mu }^{+}{\mu }^{-}$ and $D^{+}\to {\pi }^{+}{\mu }^{+}{\mu }^{-}$ decay modes which are induced through $c\to u{\mu }^{+}{\mu }^{-}$ transition.

    hep-phhep-exEPJC(2022)·11 citations
16. 16*

    Parton shower effects in $t\bar{t}{W}^{\pm }$ production at NLO QCD

    Manfred Kraus🇺🇸

    We present a selection of results from our recent study of $pp\to t\bar{t}{W}^{\pm }$ production matched to partons showers at NLO QCD at the LHC. Theoretical predictions are obtained at perturbative orders $\mathcal{O}({\alpha }_s^3\alpha )$ and $\mathcal{O}({\alpha }_s{\alpha }^3)$, where the different contributions are studied first separately at the inclusive level before being combined within a realistic two same-sign lepton signature. We investigate in detail uncertainties originating from missing higher-order corrections and from the parton-shower matching scheme employed.

    hep-phPoS(2022)·1 citation
17. 17*

    Charged and CP-violating Kink Solutions in the Two Higgs Doublet Model

    Kai Hong Law🇬🇧 · Apostolos Pilaftsis🇬🇧

    Minimal extensions of the Standard Model (SM), such as the so-called Two Higgs Doublet Model (2HDM), can possess several accidental discrete symmetries whose spontaneous breakdown in the early universe usually lead to the formation of domain walls. We extend an earlier work [arXiv:2006.13273] on this topic by studying in more detail the analytic properties of electrically charged and CP-violating kink solutions in the $Z_2$-symmetric 2HDM. We derive the complete set of equations of motion that describe the 1D spatial profile of both the 2HDM vacuum parameters and the would-be Goldstone bosons $G^{1,2,3}$ of the SM. These equations are then solved numerically using the gradient flow technique, and the results of our analysis are presented in different parametrizations of the Higgs doublets. In particular, we show analytically how an electrically charged profile should arise in 1D kink solutions when asymmetric boundary conditions are imposed on the Goldstone mode $G^2$ at spatial infinities, i.e. as $x\to \pm \infty$. If asymmetric boundary conditions are selected at $x\to \pm \infty$ for the Goldstone mode $G^3$ or the longitudinal mode $\theta$ corresponding to a would-be massive photon, the derived kink solutions are then shown to exhibit CP violation. Possible cosmological implications of the electrically charged and CP-violating domain walls in the 2HDM are discussed.

    hep-phhep-thPRD(2022)·16 citations
18. 18*

    BFKL phenomenology: resummation of high-energy logs in inclusive processes

    Francesco Giovanni Celiberto🇮🇹 · Michael Fucilla🇮🇹 · Dmitry Yu. Ivanov🇷🇺 · Mohammed M.A. Mohammed🇮🇹 · Alessandro Papa🇮🇹

    We present recent phenomenological studies, tailored on kinematic configurations typical of current and forthcoming analyses at the LHC, for two novel probe channels of the BFKL resummation of energy logarithms. Particular attention is drawn to the behavior of distributions differential in azimuthal angle and rapidity, where significant high-energy effects are expected.

    hep-phSciPost Phys.Proc.(2022)·25 citations
19. 19*

    Search for sterile neutrinos by shower events at a future neutrino telescope

    Yabin Wang🇯🇵 · Osamu Yasuda🇯🇵

    It is pointed out that searching for sterile neutrinos at high energy regions at a future IceCube-like facility has advantages compared with that of reactor or short baseline accelerator neutrino experiments, in which the size of the detector and energy resolution make it difficult to gain good sensitivity for a large mass-squared difference. In this study we show that it is possible to improve constraints on sterile neutrino mixing ${\theta }_{14}$ for 1 eV${}^2\lesssim \Delta m_{41}^2\lesssim$ 100 eV${}^2$ by looking for a dip in the shower events at an IceCube-like neutrino telescope whose volume is at least 10 times as large as that of IceCube and duration is 10 years. We also give an analytic expression for the oscillation probabilities in two cases where the condition of one mass scale dominance is satisfied.

    hep-phPTEP(2022)·3 citations
20. 20*

    Higher-order corrections to the kinetic mass definition for the bottom and the charm quarks

    Matteo Fael🇩🇪

    In these proceedings we discuss the relation between the kinetic and the on-shell schemes for the bottom and the charm quarks and present the methods for the calculation of the mass relation to higher orders in perturbative QCD. The bottom mass in the kinetic scheme is a pivotal input parameter in the inclusive determination of $|V_{cb}|$ from $B\to X_c\ell {\nu }_{\ell }$ decays. By combining the relation between the kinetic and the on-shell mass with well-know results for the $\overline{\mathrm{MS}}$-on-shell conversion, we obtain a prediction for $m_b^{\mathrm{kin}}$ based on precise determinations of ${\overline{m}}_b({\overline{m}}_b)$.

    hep-phSciPost Phys.Proc.(2022)·1 citation
21. 21*

    A full parametrization of the $9\times 9$ active-sterile flavor mixing matrix in the inverse or linear seesaw scenario of massive neutrinos

    He-chong Han🇨🇳 · Zhi-zhong Xing🇨🇳

    The inverse and linear seesaw scenarios are two typical extensions of the canonical seesaw mechanism, which contain much more sterile degrees of freedom but can naturally explain the smallness of three active neutrino masses at a sufficiently low energy scale (e.g., the TeV scale). To fully describe the mixing among three active neutrinos, three sterile neutrinos and three extra gauge-singlet neutral fermions in either of these two seesaw paradigms, we present the {\it first} full parametrization of the $9\times 9$ flavor mixing matrix in terms of 36 rotation angles and 36 CP-violating phases. The exact inverse and linear seesaw formulas are derived, respectively; and possible deviations of the $3\times 3$ active neutrino mixing matrix from its unitary limit are discussed by calculating the effective Jarlskog invariants and unitarity nonagons.

    hep-phNPB(2021)·17 citations
22. 22*

    Form factors and branching fraction calculations for $B_s\to D_s^{(\ast )}{\ell }^{+}{\nu }_{\ell }$ in view of LHCb observation

    Nakul R. Soni🇮🇳 · Aidos Issadykov🇷🇺 · Akshay N. Gadaria🇮🇳 · Zhomart Tyulemissov🇷🇺 · Janaki J. Patel🇮🇳 · Jignesh N. Pandya🇮🇳

    In light of the LHCb observations about the $B_s\to D_s^{(\ast )}\ell {\nu }_{\ell }$ semileptonic decays, we study these channels within the Standard Model framework of covariant confined quark model. The necessary transition form factors are computed in the entire dynamical range of momentum transfer squared with built-in infrared confinement. Our computed ratios of the decay widths from tau mode to muon mode for $D_s$ and $D_s^{\ast }$ mesons are found to be $R(D_s)=0.271\pm 0.069$ and $R(D_s^{\ast })=0.240\pm 0.038$. We further determine the ratio of the decay width from $D_s$ and $D_s^{\ast }$ channel for muon mode $\Gamma (B_s\to D_s{\mu }^{+}{\nu }_{\mu })/\Gamma (B_s\to D_s^{\ast }{\mu }^{+}{\nu }_{\mu })=0.451\pm 0.093$. Our results are in excellent agreement with the data from the latest LHCb experiments as well as lattice quantum chromodynamics simulations. We also compare the shape of differential decay distribution for $B_s\to D_s^{\ast }{\mu }^{+}{\nu }_{\mu }$ with the LHCb data and our results are in very good agreement throughout all the individual bins. Some other physical observables such as forward-backward asymmetry and longitudinal polarizations of leptons in the final state are also computed.

    hep-phEur.Phys.J.Plus(2023)·23 citations
23. 23*

    Heavy-flavored emissions in hybrid collinear/high-energy factorization

    Andrèe Dafne Bolognino🇮🇹 · Francesco Giovanni Celiberto🇮🇹 · Michael Fucilla🇮🇹 · Dmitry Yu. Ivanov🇷🇺 · Alessandro Papa🇮🇹

    Heavy-flavored emissions have been always considered as an excellent channel to test properties of Quantum chromodynamics (QCD) at present and future colliders. Among different regimes, in which heavy-flavor production can be investigated, we focus our attention on the semi-hard one, where $s\gg \{Q^2\}\gg {\Lambda }_{QCD}$ ($s$ is the squared center-of-mass energy, $\{Q^2\}$ a (set of) hard scale(s) characteristic of the process and ${\Lambda }_{QCD}$ the QCD mass scale). Here, we build predictions in a hybrid collinear/high-energy factorization, in which the standard collinear description is supplemented by the Balitsky-Fadin-Kuraev-Lipatov resummation of large energy logarithms. The definition and the study of observables sensitive to high-energy dynamics in the context of heavy-flavor physics has the double advantage of (i) allowing to get a stabilization of the BFKL series under higher-order corrections and (ii) providing us with an auxiliary tool to investigate heavy-flavor production in wider kinematical ranges. Hence, we propose a scientific program on heavy-flavor physics at high-energy with the goal of considering both open (heavy-jet) and bound states ($\Lambda$ baryons, heavy-light mesons and quarkonia).

    hep-ph11 citations
24. 24*

    Impacts of (inverse) magnetic catalysis on screening masses of neutral pions and sigma mesons in hot and magnetized quark matter

    Bing-kai Sheng🇨🇳 · Xinyang Wang🇨🇳 · Lang Yu🇨🇳

    We investigate the screening masses of neutral pions and sigma mesons in hot and magnetized quark matter in the framework of a two-flavor lattice-improved Nambu-Jona-Lasinio (NJL) model with a magnetic field dependent coupling constant, which is determined by utilizing the results from lattice QCD simulations. Since such model can well reproduce inverse magnetic catalysis (IMC), by comparing with the standard NJL model, we systemically analyze the impacts of IMC on the temperature and magnetic field dependences of the longitudinal and transverse screening masses of the chiral partners, i.e. {\pi}^0 and {\sigma} mesons, as well as the screening mass differences between them. Particularly, it is found that the eB dependences of two alternative (pseudo)critical temperatures for the chiral transition defined by {\sigma}-{\pi}^0 meson screening mass differences are consistent with that defined by the quark condensate.

    hep-phnucl-thPRD(2022)·25 citations
25. 25*

    CP violation in the Higgs sector at ILC

    T. Agatonović-Jovin🇷🇸 · N. Vukašinović🇷🇸 · I. Božović-Jelisavčić🇷🇸 · G. Kačarević🇷🇸 · M. Radulović🇷🇸 · J. Stevanović🇷🇸 · G. Milutinović-Dumbelović🇷🇸 · I. Smiljanić🇷🇸

    CP violation is one of Sakharov's conditions for the matter-antimatter asymmetry of the Universe. The experimentally observed size of CP violation is insufficient to account for this. Is CP violated in the Higgs sector? Could the SM-like Higgs boson be a mixture of CP even and CP odd states of an extended Higgs sector? With what precision could such effects be measured at future electron-positron colliders? These questions will be discussed in the light of the latest studies at ILC.

    hep-phPoS(2022)·1 citation
26. 26*

    Direct numerical evaluation of multi-loop integrals without contour deformation

    Roberto Pittau🇪🇸 · Bryan Webber🇬🇧

    We propose a method for computing numerically integrals defined via $iϵ$ deformations acting on single-pole singularities. We achieve this without an explicit analytic contour deformation. Our solution is then used to produce precise Monte Carlo estimates of multi-scale multi-loop integrals directly in Minkowski space. We corroborate the validity of our strategy by presenting several examples ranging from one to three loops. When used in connection with four-dimensional regularization techniques, our treatment can be extended to ultraviolet and infrared divergent integrals.

    hep-phhep-thEPJC(2022)·14 citations
27. 27*

    Colouring the Higgs boson

    Andy Buckley🇬🇧 · Giuseppe Callea🇬🇧 · Andrew J. Larkowski🇺🇸 · Simone Marzani🇮🇹

    The jet colour ring is a novel colour tagger observable designed to separate the decay of a colour-singlet into two jets from a two-jet background in a different colour configuration. Simulation studies in the case of the production of a boosted Higgs boson decaying in two b-quarks and an associate electroweak boson, showed notable discriminator powers when comparing the jet colour ring performances with other observables. These results are opening a wide scenario for further studies.

    hep-phSciPost Phys.Proc.(2022)·1 citation
28. 28*

    Dark Radiation in Spectator Axion-Gauge Models

    Mitsuru Kakizaki🇯🇵 · Masahito Ogata🇯🇵 · Osamu Seto🇯🇵

    In the framework of axion-gauge fields models, primordial gravitational wave perturbations could be generated during the inflationary epoch from not only the quantum fluctuation of gravitons but also the dynamics of hidden gauge fields coupled with an axion field. We investigate the evolution of the axion and the gauge field of an additional hidden SU(2) gauge group and those energy densities during and after the inflation. We show that the extra radiation component of the hidden gauge bosons produced by the axion decay can be sizable in the cases where the gauge fields sourced additional gravitational waves is subdominant. We point out that future measurements of the dark radiation energy, such as CMB-S4, can impose significant constraints on this cosmological scenario.

    hep-phastro-ph.COPTEP(2022)·6 citations
29. 29*

    Determining the Neutrino Mass Eigenstates and the effective Majorana Mass

    Z.B. Todorovic🇷🇸

    This paper aims at solving several open questions in current neutrino physics: the neutrino mass hierarchy, the Dirac CP-violating phase, the absolute mass of neutrinos, the nature of neutrinos (Dirac or Majorana), the Majorana matrix, and the absolute value of the effective Majorana neutrino mass. In the research presented in this paper, we have shown that the precise definition of the mass splittings between neutrino mass eigenstates, done in the latest analysis of experimental data, can be of crucial importance for defining the nature of neutrino mass hierarchy. The Standard Model has three generations of fundamental matter particles. Three generations of the charged lepton mass show a hierarchical structure. Owing to that, there is a belief and it is considered that neutrinos may follow such a hierarchical structure. In our calculations, we have also included the latest data obtained, based on the processing of measurement results, which showed that even with such data, obtained results favor the normal neutrino mass hierarchy. As for the individual neutrino mass calculated in this paper, in today's neutrino physics it is only known that the neutrino mass scale is bounded only from above, and both the Dirac and the Majorana character of neutrinos are compatible with all observations. Among some of the questions resolved in this paper, which are related to the properties of neutrinos, a positive answer was also given to the question of whether light neutrinos are self-conjugate particles or not.

    hep-phJHEP Grav.Cosmol.(2022)·2 citations
30. 30*

    $VH+\text{jet}$ production in hadron-hadron collisions up to order ${\alpha }_s^3$ in perturbative QCD

    R. Gauld🇳🇱 · A. Gehrmann-De Ridder🇨🇭 · E. W. N. Glover🇬🇧 · A. Huss🇨🇭 · I. Majer🇨🇭

    We present precise predictions for the hadronic production of an on-shell Higgs boson in association with a leptonically decaying gauge boson and a jet up to order ${\alpha }_s^3$. We include the complete set of NNLO QCD corrections to both charged- and neutral-current Drell-Yan type contributions, as well as the previously known leading heavy quark loop induced contributions which involve a direct Higgs-quark coupling. As an application, we study a range of differential observables in proton-proton collisions at $\sqrt{s}=13\text{TeV}$ for both the charged- and neutral-current production modes. For each Higgs production process, we assess the improvement in the theoretical uncertainty for both the exclusive ($n_{\text{jet}}=1$) and inclusive ($n_{\text{jet}}\ge 1$) jet categories. We find that the inclusion of the NNLO corrections to the Drell-Yan type contributions is essential in stabilising the predictions and in reducing the theoretical uncertainty for both inclusive and exclusive jet production for all three modes. This is particularly true in the kinematical regimes associated with low to medium values of the transverse momentum of the produced vector boson and where the differential cross sections are the largest. For the neutral-current process, we find that the heavy quark loop induced contributions have their largest phenomenological impact (an increase in the size of the NNLO corrections, a distortion of the distribution shape and an enlargement of the left over remaining uncertainties) in kinematical regions associated to large values of $p_{T,Z}$ (typically above $150\text{GeV}$) where the cross sections are smaller.

    hep-phhep-exJHEP(2022)·30 citations
31. 31*

    The multicomponent dark matter structure and its possible observed manifestations

    V. Beylin🇷🇺 · V. Kuksa🇷🇺 · M. Bezuglov🇷🇺 · D. Sopin🇷🇺

    In the framework of hypercolor extension of the Standard Model having vectorlike hyperquarks and two stable dark matter candidates originated from different hyper-currents, we consider some effects which result from reactions with participation of the dark matter components. Namely, there are decays of charged hyperpions into leptons and neutral component, annihilation and transitions of heavy dark matter candidates into the light ones. In the last case, low energy photon radiation from intermediate charged states is possible. This type of the dark matter luminescence is analyzed in more detail.

    hep-ph0 citations
32. 32*

    Intermittency in pp collisions at $\sqrt{s}=$ 0.9, 7 and 8 TeV from the CMS collaboration

    Z. Ong🇸🇬 · P. Agarwal🇸🇬 · H.W. Ang🇸🇬 · A.H. Chan🇸🇬 · C.H. Oh🇸🇬

    The intermittency-type fluctuations as outlined by Bialas and Peschanski in the 1980s is analysed in $pp$ collisions at $\sqrt{s}=$ 0.9, 7 and 8 TeV from the CMS collaboration at CERN. Our preliminary analysis shows that the intermittency exponents in the bin-averaged scaled factorial moments decrease in magnitude with increasing collision energy at the TeV scale, which suggests that the cascading nature of multiparticle production described by the $\alpha$-model is weakening. We outline possible areas planned for future studies.

    hep-phhep-exSciPost Phys.Proc.(2022)·5 citations
33. 33*

    Sea quark contributions to the electromagnetic form factors of $\Sigma$ hyperons

    Mingyang Yang🇨🇳 · Ping Wang🇨🇳

    We study the sea quark contributions to the electromagnetic form factors of $\Sigma$ baryons with nonlocal chiral effective theory. Both octet and decuplet intermediate states are included in the one loop calculation. $G_{{\Sigma }^{-}}^u$ and $G_{{\Sigma }^{+}}^d$ could be priority observables for the examination of sea quark contributions to baryon structure because these quantities are much larger than the strange form factors of nucleon. It will be less difficult for lattice simulation to determine the sign of these pure sea quark contributions unambiguously. In ${\Sigma }^0$, the light sea quark form factors $G_{{\Sigma }^0}^u$ and $G_{{\Sigma }^0}^d$ are identical. Since the light sea quark form factors in proton are different, it will be more meaningful to compare lattice result of the light sea quark form factors in ${\Sigma }^0$ with that obtained from effective field theory.

    hep-phPRD(2022)·1 citation
34. 34*

    Hadron Production in terms of Green's Functions in Non-Equilibrium Matter

    A.V.Koshelkin🇷🇺

    Following the quark-hadron duality concept, we show that the number of hadrons generated in the deconfinement matter is entirely determined by the exact non-equilibrium Green's functions of partons in the medium and the vertex function governing the probability of the confinement-deconfinement phase transition. In such an approach, compactifying the standard (3+1) chromodynamics into $QC{D}_{xy}+QC{D}_{zt}$, the rate of the hadrons produced in particle collisions is derived in the explicit form provided that the hadronization is the first order phase transition. The pion production is found to be in good agreement to the experimental results on the pion yield in pp collisions.

    hep-phhep-thnucl-thSciPost Phys.Proc.(2022)·0 citations
35. 35*

    Radiative Semileptonic $\bar{B}$ Decays

    Michele Papucci🇺🇸 · Tanner Trickle🇺🇸 · Mark B. Wise🇺🇸

    We consider the form factors for the radiative semileptonic decays $\bar{B}(v)\to D^{(\ast )}(v^{\prime })\ell {\bar{\nu }}_{\ell }\gamma$ in the kinematic region where the photon momentum, $k$, is small enough that heavy quark symmetry (HQS) can be applied without the radiated photon changing the heavy quark velocity (i.e., $v^{(\prime )}\cdot k<m_{(b,c)}$). We find that HQS is remarkably powerful, leaving only four new undetermined form factors at leading order in $1/m_{(b,c)}$. In addition, one of them is fixed in terms of the leading order Isgur-Wise function in the kinematic region, $v^{(\prime )}\cdot k<{\Lambda }_{\text{QCD}}$.

    hep-phhep-exJHEP(2022)·7 citations
36. 36*

    Resonant excitation of the axion field during the QCD phase transition

    Pierre Sikivie🇺🇸 · Wei Xue🇺🇸

    We find that the adiabatic fluctuations produced in the primordial plasma by cosmological inflation resonantly excite the axion field during the QCD phase transition by pumping axions from low momentum modes to modes with momentum up to of order $\sqrt{3}m$ where $m$ is the axion mass. We derive the momentum distribution of the excited axions. The fraction of cold axions that get excited is of order one if the axion mass is larger than a few $\mu$eV. The effect occurs whether inflation happens before or after the Peccei-Quinn phase transition.

    hep-phastro-ph.COPRD(2022)·15 citations
37. 37*

    Disentangling Jet Modification in Jet Simulations and in Z+Jet Data

    Jasmine Brewer🇨🇭 · Quinn Brodsky🇺🇸 · Krishna Rajagopal🇺🇸

    We study the impact of selection biases on jet structure and substructure observables and separate these effects from effects caused by jet quenching. We use the angular separation $\Delta R$ of the hardest splitting in a jet as the primary example observable. We first conduct a simplified Monte Carlo study in which it is possible to identify the same jet after quenching in a heavy ion collision and as it would have been if it had formed in vacuum. We select a sample of jets by placing a cut on their quenched $p_T$ and, as is possible only in a Monte Carlo study, compare to the same jets unquenched, and see that the $\Delta R$ distribution seems to be unmodified. However, if we select a sample of jets formed in vacuum by placing a cut on their unquenched $p_T$ and compare to those same jets after quenching, we see a significant enhancement in the number of jets with large $\Delta R$, primarily due to the soft particles in the jet that originate from the wake in the droplet of quark-gluon plasma excited by the parton shower. We confirm that the jets contributing to this enhancement are those jets which lost the most energy, which were not included in the sample selected after quenching; jets selected after quenching are those which lose a small fraction of their energy. Next, we employ a method that is available to experimentalists: in a sample of jets with a recoiling $Z$ boson, we show that selecting jets based on the jet $p_T$ after quenching yields a $\Delta R$ distribution that appears unmodified while selecting a sample of jets produced in association with a $Z$ boson whose (unmodified) $p_T$ is above some cut yields a significant enhancement in the number of jets with large $\Delta R$. We again confirm that this is due to particles from the wake, and that the jets contributing to this enhancement are those which have lost a significant fraction of their energy.

    hep-phnucl-thJHEP(2022)·50 citations
38. 38*

    Ultra-High Energy Proton-Proton Collision in the Laboratory System as the Source of Proton, Neutrino and Gamma Spectra in Astrophysics

    O.I. Piskounova🇷🇺

    This paper is dedicated to the study how HE particle spectra, which are measured in cosmic ray physics and astrophysics, are influenced by the specifics of collider spectrum of protons.LHC experiments are providing us with the proton spectra at very high energy (VHE) measured in center-of-mass system. A QCD phenomenological study of previous years gave us the Quark-Gluon String Model for the modeling of baryon and meson production spectra in full kinematical range from centrally produced hadrons up to very forward ones. In 1990, I have applied the method for the recalculation the collider distribution of neutral pions for the description of gamma spectrum from supernova that was measured in the laboratory system. Here, I used the same method. The main statement of this study is that the features of leading spectra of cosmic protons, neutrinos and gamma are to be formed already in first collision of UHE proton at the power source of cosmic particles. The specifics of collider spectrum of protons are as following: the growing distribution at the central rapidity's, which reflects in the "knee" of cosmic proton spectrum, and the triple-Pomeron peak at the end of c.m.s. spectrum that leads to the enhancements in spectra of leading cosmic protons, neutrinos, gamma-photons, and as I assume, positrons too. These conclusions desire for more experimental facts to be collected and new observations to be made.

    hep-phPoS(2022)·0 citations
39. 39*

    Generative Networks for Precision Enthusiasts

    Anja Butter🇩🇪 · Theo Heimel🇩🇪 · Sander Hummerich🇩🇪 · Tobias Krebs🇩🇪 · Tilman Plehn🇩🇪 · Armand Rousselot🇩🇪 · Sophia Vent🇩🇪

    Generative networks are opening new avenues in fast event generation for the LHC. We show how generative flow networks can reach percent-level precision for kinematic distributions, how they can be trained jointly with a discriminator, and how this discriminator improves the generation. Our joint training relies on a novel coupling of the two networks which does not require a Nash equilibrium. We then estimate the generation uncertainties through a Bayesian network setup and through conditional data augmentation, while the discriminator ensures that there are no systematic inconsistencies compared to the training data.

    hep-phcs.LGSciPost Phys.(2023)·90 citations
40. 40*

    Photon interactions with superconducting topological defects

    Richard A. Battye🇬🇧 · Dominic G. Viatic🇬🇧

    Using a toy model for the interactions between a defect-forming field and the photon field where the photon becomes massive in the defect core (motivated by recent work on defects in the 2HDM), we study the impact on photon propagation in the background of the defect. We find that, when the photon frequency (in natural units) is much lower than the symmetry breaking scale, domain walls reflect most of an incoming photon signal leading to potential interesting astrophysical signals. We also adapt the calculations for vortices and monopoles. We find that the case of strings is very similar to the standard case for massive scalar particles, but in the case of monopoles the cross-section is proportional to the geometrical area of the monopole.

    hep-phastro-ph.COPLB(2021)·10 citations
41. 41*

    Neutron-Mirror Neutron oscillations in Matter

    Yuri Kamyshkov🇺🇸 · James Ternullo🇺🇸 · Louis Varriano🇺🇸 · Zurab Berezhiani🇮🇹

    The possibility that a neutron can be transformed to a hidden sector particle remains intriguingly open. Proposed theoretical models conjecture that the hidden sector can be represented by a mirror sector, and the neutron n can oscillate into its sterile mirror twin n', exactly or nearly degenerate in mass with n. Oscillations n - n' can take place in vacuum and in the environment of the regular matter and the magnetic field where only neutron will be subject of interaction with the environment. We describe the propagation of the oscillating n - n' system as a particle of the cold neutron beam passing through the dense absorbing materials in connection with the possible regeneration type of experiments where the effect of n -> n' -> n transformation can be observed.

    hep-phnucl-exnucl-thSymmetry(2022)·19 citations
42. 42*

    Cosmological "constant" in a universe born in the metastable false vacuum state

    Krzysztof Urbanowski🇵🇱

    The cosmological constant $\Lambda$ is a measure of the energy density of the vacuum. Therefore properties of the energy of the system in the metastable vacuum state reflect properties of $\Lambda =\Lambda (t)$. We analyze properties of the energy, $E(t)$, of a general quantum system in the metastable state in various phases of the decay process: In the exponential phase, in the transition phase between the exponential decay and the later phase, where decay law as a function of time $t$ is in the form of powers of $1/t$, and also in this last phase. We found that this energy having an approximate value resulting from the Weisskopf--Wigner theory in the exponential decay phase is reduced very fast in the transition phase to its asymptotic value $E(t)\simeq E_{min}+{\alpha }_2/t^2+\dots$ in the late last phase of the decay process. (Here $E_{min}$ is the minimal energy of the system). This quantum mechanism reduces the energy of the system in the unstable state by a dozen or even several dozen orders or more. We show that if to assume that a universe was born in metastable false vacuum state then according to this quantum mechanism the cosmological constant $\Lambda$ can have a very great value resulting from the quantum field theory calculations in the early universe in the inflationary era, $\Lambda \simeq {\Lambda }_{qft}$, and then it can later be quickly reduced to the very, very small values.

    ↳ gr-qcastro-ph.COhep-phquant-phEPJC(2022)·8 citations
43. 43*

    Thermal QCD with external imaginary electric fields on the lattice

    Gergely Endrodi🇩🇪 · Gergely Marko🇩🇪

    We study QCD at finite temperature in the presence of imaginary electric fields. In particular, we determine the electric susceptibility, the leading coefficient in the expansion of the QCD pressure in the imaginary field. Unlike for magnetic fields, at nonzero temperature this coefficient requires a non-trivial separation of genuine electric field-related effects and spurious effects related to the chemical potential, which becomes an unphysical gauge parameter in this setting. Our results are based on lattice simulations with stout improved dynamical staggered quarks at physical quark masses.

    ↳ hep-lathep-phhep-thnucl-thPoS(2022)·8 citations
44. 44*

    Unit conversions and collected numbers in cosmology

    Eemeli Tomberg🇪🇪

    This note collects together useful unit conversions and numerical values from early universe cosmology. It is a quick reference that can be used to make easy order-of-magnitude estimates. Included are tables for unit conversions, the thermal history of the universe, and collected properties of astronomical objects. The note also introduces a modifiable Mathematica package NaturalUnits (newest version 2.0), which makes it easy to convert between natural and physical units.

    ↳ astro-ph.COhep-ph14 citations
45. 45*

    Hawking-Like Radiation as Tunneling from a Cosmological Black Hole in Modified Gravity: Semiclassical Approximation and Beyond

    Sara Saghafi🇮🇷 · Kourosh Nozari🇮🇷

    Hawking radiation as a quantum phenomenon is generally attributed to the existence of the event horizon of a black hole. However, we demonstrate in this paper that there is indeed ingoing Hawking-like radiation associated with apparent horizons of the first cosmological black hole solution in the framework of Scalar-Tensor-Vector Gravity (STVG) theory living in the Friedmann-Lema\^ıtre-Robertson-Walker (FLRW) background. Such radiation can be attributed also to the cosmological apparent horizon of the FLRW universe and even to the cosmological event horizon of de Sitter spacetime. We see how STVG theory as a good theory for explaining black holes both on local and global scales affect the Hawking effect. Based on semiclassical approximation, we follow Hamilton-Jacobi and Parikh-Wilczek tunneling methods, respectively with and without back-reaction effects. We find out that back-reaction effects make a correlation between the emission modes in Parikh-Wilczek tunneling formalism, which can address the information paradox. We obtain the corresponding Hawking-like temperature as a function of inverse powers of apparent horizons radiuses of the cosmological black hole in STVG theory. We analyze the influence of the STVG parameter associated with a deviation of the STVG theory from General Theory of Relativity (GR) on both apparent horizons and the Hawking-like temperature of the cosmological black hole. We show that increasing the STVG parameter results in appearing the Hawking-like temperature in later cosmic times with some smaller values. Also, we follow the Hamilton-Jacobi approach beyond semiclassical approximation to involve all quantum correction terms in the deduced semiclassical outcomes for the cosmological black hole in the STVG theory.

    ↳ gr-qchep-phGen.Rel.Grav.(2023)·15 citations
46. 46*

    Lattice study of the confinement/deconfinement transition in rotating gluodynamics

    V.V. Braguta🇷🇺 · A.Yu. Kotov🇩🇪 · D.D. Kuznedelev🇷🇺 · A.A. Roenko🇷🇺

    We study the influence of relativistic rotation on the confinement/deconfinement phase transition in gluodynamics by means of lattice simulations. The simulation is performed in the reference frame which rotates with the system under investigation, where rotation is reduced to external gravitational field. The Polyakov loop and its susceptibility are calculated for various lattice parameters and values of angular velocities which are characteristic for heavy-ion collision experiments. Different types of boundary conditions (open, periodic, Dirichlet) are imposed in directions, orthogonal to rotation axis. It is shown, that the critical temperature of the confinement/deconfinement transition in gluodynamics grows quadratically with increasing angular velocity. This conclusion does not depend on the boundary conditions used in our study and we believe that this is universal property of gluodynamics. We also present first results of the study of the phase diagram of rotating QCD matter with fermions. The results indicate, that effect of the rotation on fermions is opposite to gluons: it leads to the decrease of the critical temperature.

    ↳ hep-lathep-phhep-thPoS(2022)·24 citations
47. 47*

    AdS/QCD oddball masses and Odderon Regge trajectory from a twist-five operator approach

    Eduardo Folco Capossoli🇧🇷 · J. P. Morais Graça🇧🇷 · Henrique Boschi-Filho🇧🇷

    In this work, we consider a massive gauge boson field in AdS${}_5$ dual to odd glueball states with twist-5 operator in 4D Minkowski spacetime. Introducing an IR cutoff we break the conformal symmetry of the boundary theory allowing us to calculate the glueball masses with odd spins using Dirichlet and Neumann boundary conditions. Then, from these masses we construct the corresponding Regge trajectories associated with the odderon. Our results are compatible with the ones in the literature.

    ↳ hep-thhep-phPRD(2022)·7 citations
48. 48*

    Regulating loops in de Sitter spacetime

    Akhil Premkumar🇺🇸

    Perturbative quantum field theory (QFT) calculations in de Sitter space are riddled with contributions that diverge over time. These contributions often arise from loop integrals, which are notoriously hard to compute in de Sitter. We discuss an approach to evaluate loop integrals that contribute to equal-time correlators of a scalar field theory in a fixed de Sitter background. Our method is based on the Mellin-Barnes representation of correlation functions, which allows us to regulate loop divergences by adjusting the masses of the fields, or by gently deforming the underlying de Sitter spacetime. The resulting expressions have a similar structure as a standard answer from dimensional regularization in flat space QFT. These features of the regulator are illustrated with two examples, worked out in detail. Along the way, we illuminate the physical origin of these divergences and their interpretation with the machinery of the dynamical renormalization group. Our approach regulates the IR divergences of massless and massive particles in the same way. For massless scalars, the loop corrections can be incorporated as systematic improvements to the stochastic inflation framework, allowing for a more precise description of the IR dynamics of such fields in de Sitter.

    ↳ hep-thhep-phPRD(2024)·43 citations
49. 49*

    The ubiquity of black holes in modern physics

    Jorge V. Rocha🇵🇹

    This is a translation of an article written originally in Portuguese for the journal Gazeta de Física, in a special edition celebrating the 2020 Nobel prize in physics. The text targets a broad audience and focuses on the key ideas and developments in an entirely non-technical fashion, requiring from the reader only a keen interest in theoretical physics. The aim is to explain in an accessible way -- employing only basic and intuitive concepts -- the huge influence black holes have had in modern theoretical physics. Among the various topics covered, string theory and the AdS/CFT correspondence, extra dimensions, the quark-gluon plasma and holographic superconductors are highlighted.

    ↳ physics.pop-phgr-qchep-phhep-th0 citations
50. 50*

    Constraints on small-scale primordial density fluctuation from cosmic microwave background through dark matter annihilation

    Masahiro Kawasaki🇯🇵 · Hiromasa Nakatsuka🇯🇵 · Kazunori Nakayama🇯🇵

    The cosmic microwave background (CMB) observation by the Planck satellite precisely determines primordial curvature fluctuations on larger scales than $\mathcal{O}(1)\mathrm{Mpc}$, while the small-scale curvature fluctuation is still less constrained. The constraint on small-scale fluctuations is highly improved if we assume the standard thermal relic dark matter scenario. When small-scale fluctuations are large enough, dense regions collapse to form small halos even in a redshift $z\gtrsim 10^3$, which is called ultracompact minihalos. These minihalos enhance the annihilation of the dark matter and it is constrained by observations such as extragalactic gamma rays and the CMB. We revisit the effect of minihalos formed by the small-scale density fluctuations and calculate the ionization history modified by the dark matter annihilation. We perform the Markov Chain Monte Carlo method to constrain the size of small-scale curvature fluctuations by the CMB power spectrum. It is found that the constraint from the CMB power spectrum is comparable to that from the extragalactic gamma rays. We confirm that our constraint mainly comes from the energy injection in early time ($z\gtrsim 100$) and hence it is independent of the uncertainty of minihalo properties in the late time.

    ↳ astro-ph.COhep-phJCAP(2022)·11 citations
51. 51*

    Relativistic star perturbations in Horndeski theories with a gauge-ready formulation

    Ryotaro Kase🇯🇵 · Shinji Tsujikawa🇯🇵

    We present a general framework for studying the relativistic star perturbations on a static and spherically symmetric background in full Horndeski theories. We take a perfect fluid into account as a form of the Schutz-Sorkin action. Our formulation is sufficiently versatile in that the second-order actions of perturbations in odd- and even-parity sectors are derived without choosing particular gauge conditions, so they can be used for any convenient gauges at hand. The odd-parity sector contains one dynamical gravitational degree of freedom coupled to a time-independent four velocity of the fluid. In the even-parity sector there are three dynamical perturbations associated with gravity, scalar field, and matter sectors, whose equations of motion are decoupled from other nondynamical perturbations. For high radial and angular momentum modes, we obtain the propagation speeds of all dynamical perturbations and show that the perfect fluid in the even-parity sector has a standard sound speed affected by neither gravity nor the scalar field. Our general stability conditions and perturbation equations of motion can be directly applied to the stabilities of neutron stars and black holes as well as the calculations of their quasi-normal frequencies.

    ↳ gr-qchep-phhep-thPRD(2022)·36 citations
52. 52*

    Lattice pure gauge compact QED in the Landau gauge: the photon propagator, the phase structure and the presence of Dirac strings

    Lee C. Loveridge🇵🇹 · Orlando Oliveira🇵🇹 · Paulo J. Silva🇵🇹

    In this work we investigate the lattice Landau gauge photon propagator together with the average number of Dirac strings in the compact formulation of QED for the pure gauge version of the theory as a function of the coupling constant. Their $\beta$ dependence show that these two quantities can be used to identify the confinement-deconfinement transition and that the nature of this transition is first order. Our results show that in the confined phase the propagator is always finite, the theory has a mass gap and the number of Dirac strings present in the configuration is two orders of magnitude larger than in the deconfined phase. Furthermore, in the deconfined phase where $\beta \ge 1.0125$ the theory becomes massless, there are essentially no Dirac strings and the photon propagator diverges when the limit $p\to 0^{+}$ is taken. Our results illustrate the importance of the topological structures in the dynamics of the two phases.

    ↳ hep-lathep-phPRD(2021)·9 citations
53. 53*

    Constraining exotic compact stars composed of bosonic and fermionic dark matter with gravitational wave events

    Stephan Wystub🇩🇪 · Yannick Dengler🇩🇪 · Jan-Erik Christian🇩🇪 · Jürgen Schaffner-Bielich🇩🇪

    We investigate neutron star-black hole (NS-BH) merger candidates as a test for compact exotic objects. Using the events GW190814, GW200105 and GW200115 measured by the LIGO-Virgo collabration, which represent a broad profile of the masses in the NS mass spectrum, we demonstrate the constraining power for the parameter spaces of compact stars consisting of dark matter for future measurements. We consider three possible cases of dark matter stars: self-interacting, purely bosonic or fermionic dark matter stars, stars consisting of a mixture of interacting bosonic and fermionic matter, as well as the limiting case of selfbound stars. We find that the scale of those hypothetical objects are dominated by the one of the strong interaction. The presence of fermionic dark matter requires a dark matter particle of the GeV mass scale, while the bosonic dark matter particle mass can be arbitrarily large or small. In the limiting case of a selfbound linear equation of state, we find that the vacuum energy of those configurations has to be similar to the one of QCD.

    ↳ astro-ph.HEhep-phnucl-thMNRAS(2023)·17 citations
54. 54*

    Lensing Signatures of a Slowly-Accelerated Black Hole

    Amjad Ashoorioon🇮🇷 · Mohammad Bagher Jahani Poshteh🇮🇷 · Robert B. Mann🇨🇦

    Accelerating black holes, connected to cosmic strings could evolve to supermassive black holes. However, if they are going to take part in structure formation and resides at the center of galaxies, their acceleration should be small. This slow acceleration does not change the shadow or image position in gravitational lensing effect significantly. However we show that the time delay associated to these images change significantly. This is in contrast with when the theory governing the strong gravitational field around the black hole is different from general relativity, where not only the differential time delays but the angular position of images would be different. We conclude that, if the observed angular position of images are compatible with the prediction of general relativity, a possible deviation in the differential time delays between the observed values and those predicted by general relativity, could be due to the acceleration of the black hole.

    ↳ gr-qcastro-ph.COhep-phhep-thPRD(2023)·12 citations
55. 55*

    Characterization of the background spectrum in DAMIC at SNOLAB

    A. Aguilar-Arevalo🇲🇽 · D. Amidei🇺🇸 · I. Arnquist🇺🇸 · D. Baxter🇺🇸 · G. Cancelo🇺🇸 · B.A. Cervantes Vergara🇲🇽 · A.E. Chavarria🇺🇸 · N. Corso🇺🇸 · E. Darragh-Ford🇺🇸 · M.L. Di Vacri🇺🇸 · J.C. D'Olivo🇲🇽 · J. Estrada🇺🇸 and 22 other authors

    We construct the first comprehensive radioactive background model for a dark matter search with charge-coupled devices (CCDs). We leverage the well-characterized depth and energy resolution of the DAMIC at SNOLAB detector and a detailed GEANT4-based particle-transport simulation to model both bulk and surface backgrounds from natural radioactivity down to 50 eV${}_{\text{ee}}$. We fit to the energy and depth distributions of the observed ionization events to differentiate and constrain possible background sources, for example, bulk ${}^3$H from silicon cosmogenic activation and surface ${}^{210}$Pb from radon plate-out. We observe the bulk background rate of the DAMIC at SNOLAB CCDs to be as low as $3.1\pm 0.6$ counts kg${}^{-1}$ day${}^{-1}$ keV${}_{\text{ee}}^{-1}$, making it the most sensitive silicon dark matter detector. Finally, we discuss the properties of a statistically significant excess of events over the background model with energies below 200 eV${}_{\text{ee}}$.

    ↳ hep-exhep-phphysics.ins-detPRD(2022)·48 citations
56. 56*

    Predictions and postdictions for relativistic lead and oxygen collisions with Trajectum

    Govert Nijs🇺🇸 · Wilke van der Schee🇨🇭

    We introduce a global analysis of relativistic heavy ion collisions using Trajectum of a significantly higher precision and including a new option to vary the normalization of the centrality estimator. We use the posterior distribution of our parameters to generate a set of high statistics samples that allows us to make precise predictions including statistical and systematic uncertainties estimated from the model parameter distribution. The results are systematically compared with experiment whereby we also include many observables not included in the global analysis. This includes in particular (extremely) ultracentral anisotropic flow and mean transverse momentum, whereby we find satisfactory agreement with experiment where data is available. Lastly, we compute spectra and anisotropic flow for oxygen-oxygen collisions performed at RHIC and to be performed at the LHC and comment on how these collisions may inform us on properties of the Quark-Gluon-Plasma.

    ↳ nucl-thhep-phnucl-exPRC(2022)·79 citations
57. 57*

    New Roads to the Small-Scale Universe: Measurements of the Clustering of Matter with the High-Redshift UV Galaxy Luminosity Function

    Nashwan Sabti🇬🇧 · Julian B. Muñoz🇺🇸 · Diego Blas🇪🇸

    The epochs of cosmic dawn and reionisation present promising avenues for understanding the role of dark matter (DM) in our cosmos. The first galaxies that populated the Universe during these eras resided in DM halos that were much less massive than their counterparts today. Consequently, observations of such galaxies can provide us with a handle on the clustering of DM in an otherwise currently inaccessible regime. In this work, we use high-redshift UV galaxy luminosity-function (UV LF) data from the Hubble Space Telescope to study the clustering properties of DM at small scales. In particular, we present new measurements of the matter power spectrum at wavenumbers $0.5{\mathrm{Mpc}}^{-1}<k<10{\mathrm{Mpc}}^{-1}$ to roughly 30% precision, obtained after marginalising over the unknown astrophysics. These new data points cover the uncharted redshift range $4\le z\le 10$ and encompass scales beyond those probed by Cosmic-Microwave-Background and large-scale-structure observations. This work establishes the UV LF as a powerful tool to probe the nature of DM in a different regime than other cosmological and astrophysical data sets.

    ↳ astro-ph.COastro-ph.GAhep-phApJL(2022)·78 citations
58. 58*

    The Four-Loop $\mathcal{N}=4$ SYM Sudakov Form Factor

    Roman N. Lee🇷🇺 · Andreas von Manteuffel🇺🇸 · Robert M. Schabinger🇺🇸 · Alexander V. Smirnov🇷🇺 · Vladimir A. Smirnov🇷🇺 · Matthias Steinhauser🇩🇪

    We present the Sudakov form factor in full color $\mathcal{N}=4$ supersymmetric Yang-Mills theory to four loop order and provide uniformly transcendental results for the relevant master integrals through to weight eight.

    ↳ hep-thhep-phJHEP(2022)·22 citations
59. 59*

    GALLUMI: A Galaxy Luminosity Function Pipeline for Cosmology and Astrophysics

    Nashwan Sabti🇬🇧 · Julian B. Muñoz🇺🇸 · Diego Blas🇪🇸

    Observations of high-redshift galaxies have provided us with a rich tool to study the physics at play during the epoch of reionisation. The luminosity function (LF) of these objects is an indirect tracer of the complex processes that govern galaxy formation, including those of the first dark-matter structures. In this work, we present an extensive analysis of the UV galaxy LF at high redshifts to extract cosmological and astrophysical parameters. We provide a number of phenomenological approaches in modelling the UV LF and take into account various sources of uncertainties and systematics in our analysis, including cosmic variance, dust extinction, scattering in the halo-galaxy connection, and the Alcock-Paczyński effect. Using UV LF measurements from the Hubble Space Telescope together with external data on the matter density, we derive the large-scale matter clustering amplitude to be ${\sigma }_8=0.76_{-0.14}^{+0.12}$, after marginalising over the unknown astrophysical parameters. We find that with current data this result is only weakly sensitive to our choice of astrophysical modelling, as well as the calibration of the underlying halo mass function. As a cross check, we run our analysis pipeline with mock data from the IllustrisTNG hydrodynamical simulations and find consistent results with their input cosmology. In addition, we perform a simple forecast for future space telescopes, where an improvement of roughly 30% upon our current result is expected. Finally, we obtain constraints on astrophysical parameters and the halo-galaxy connection for the models considered here. All methods discussed in this work are implemented in the form of a versatile likelihood code, GALLUMI, which we make public.

    ↳ astro-ph.COastro-ph.GAhep-phPRD(2022)·56 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.