Wed·Apr 6, 2022Wednesday·April 6, 2022

1. 01*

   The flair of Higgsflare: Distinguishing electroweak EFTs with $W_L{W}_L\to n\times h$

   Raquel Gomez-Ambrosio (Univ. Milano Bicocca and INFN)🇮🇹 · Felipe J. Llanes-Estrada🇪🇸 · Alexandre Salas-Bernardez🇪🇸 · Juan J. Sanz-Cillero (Univ. Complutense de Madrid and IPARCOS)🇪🇸

   The electroweak symmetry-breaking sector is one of the most promising and uncharted parts of the Standard Model; but it seems likely that new electroweak physics may be out of reach of the present accelerator effort and the hope is to observe small deviations from the SM. Given that, Effective Field Theory becomes the logic method to use, and SMEFT has become the standard. However, the most general theory with the known particle content is HEFT, and whether SMEFT suffices should be investigated in future experimental efforts. Building on investigations by other groups that established geometric criteria to distinguish SMEFT from HEFT (useful for theorists examining specific beyond-SM completions), we seek more phenomenological understanding and present an analogous discussion aimed at a broader audience. We discuss various aspects of (multi-) Higgs boson production from longitudinal electroweak gauge bosons $W_L{W}_L\to n\times h$ in the TeV region as the necessary information to characterise the Flare function, $\mathcal{F}(h)$, that determines whether SMEFT or HEFT is needed. We also present tree-level amplitudes including contact and exchange channels, as well as a short discussion on accessing $\mathcal{F}(h)$ from the statistical limit of many bosons. We also discuss the status of the coefficients of its series expansion, its validity, whether its complex-$h$ extension can be used to predict or not a tell-tale zero, and how they relate to the dimension-6 and -8 SMEFT operators in the electroweak sector. We derive a set of new correlations among BSM corrections to the HEFT coefficients that help decide, from experimental data, whether we have a viable SMEFT. This analysis can be useful for machines beyond the LHC that could address the challenging final state with several Higgs bosons.

   hep-phhep-thPRD(2022)·51 citations
2. 02*

   $\bar{B}\to D^{(\ast )}\ell \bar{X}$ decays in effective field theory with massive right-handed neutrinos

   Alakabha Datta🇺🇸 · Hongkai Liu🇮🇱 · Danny Marfatia🇺🇸

   We calculate the complete differential decay distributions for the $B$ meson decays, $\bar{B}\to D^{(\ast )}\ell \bar{X}$, to a massive right-handed (RH) neutrino in the low-energy effective field theory (LEFT) framework. We find that a massive RH neutrino does not introduce any new angular structures compared to the massless case, but can cause significant distortions in angular observables. We study the phenomenology of low-energy four-fermion operators permitted by the standard model effective field theory (SMEFT) extended with RH neutrinos (SMNEFT). We show that to explain the positive value of the difference in forward-backward asymmetries, $\Delta A_{\text{FB}}\equiv A_{\text{FB}}^{\mu }-A_{\text{FB}}^e$, tentatively inferred from Belle data, the RH neutrino must be massive. We also make predictions for $q^2$ dependent angular observables to motivate future measurements.

   hep-phhep-exPRD(2022)·24 citations
3. 03*

   Cosmological phase transitions, gravitational waves and self-interacting dark matter in the singlet extension of MSSM

   Wenyu Wang🇨🇳 · Ke-Pan Xie🇺🇸 · Wu-Long Xu🇨🇳 · Jin Min Yang🇨🇳

   In the minimal supersymmetric standard model (MSSM) extended by a singlet superfield, when the coupling between the singlet sector and the MSSM sector is tiny, the singlet sector can be a quasi dark sector with supersymmetry (SUSY). We investigate the cosmological phenomena in this scenario and obtain the following observations: (i) In the parameter space solving the small cosmological scale anomalies via self-interacting singlino dark matter (SIDM), a first-order phase transition (FOPT) can readily happen but requires rather light dark matter below MeV; (ii) The corresponding parameter space indicated by FOPT and SIDM can be partially covered by detecting the phase-transition gravitational waves (GWs) at the near-future projects, such as LISA, TianQin and Taiji. Therefore, the recently developed GW astronomy could be a novel probe to such a SUSY scenario.

   hep-phastro-ph.COEPJC(2022)·16 citations
4. 04*

   Molecular states from ${\bar{B}}^{(\ast )}N$ interactions

   Zhong-Yi Jian🇨🇳 · Hong Qiang Zhu🇨🇳 · Feng Yang🇨🇳 · Qi-Hui Chen🇨🇳 · Yin Huang🇨🇳 · Jun He🇨🇳

   In 2019, two new structures ${\Lambda }_b(6146)$ and ${\Lambda }_b(6152)$ were observed by the LHCb Collaboration at the invariant mass spectrum of ${\Lambda }_b^0{\pi }^{+}{\pi }^{-}$, which aroused a hot discussion about their inner structures. The ${\Lambda }_b(6146)$ and ${\Lambda }_b(6152)$ might still be molecular states because their masses are close to threshold of a $\bar{B}$ meson and a nucleon. In this work, we perform a systematical investigation of possible heavy baryonic molecular states from the $\bar{B}N$ interaction. Since the $\bar{B}N$ channel strongly couples to the ${\bar{B}}^{\ast }N$ channel, the possible $\bar{B}N-{\bar{B}}^{\ast }N$ bound states are also studied. The interaction of the system considered is described by the $t$-channel $\sigma$, $\pi$, $\eta$ ,$\omega$, and $\rho$ mesons exchanges. By solving the non-relativistic Schrödinger equation with the obtained one-boson-exchange potentials, the ${\bar{B}}^{(\ast )}N$ bound states with different quantum numbers are searched. The calculation suggests that recently observed ${\Lambda }_b(6146)$ can be assigned as a $P$-wave $\bar{B}N$ molecular state with spin parity $J^P=3/2^{+}$ or a $\bar{B}N-{\bar{B}}^{\ast }N$ bound state. However, assignment of ${\Lambda }_b(6152)$ as an $F$-wave $\bar{B}N$ molecular is disfavored. The ${\Lambda }_b(6152)$ can be explained as meson-baryon molecular state with a small $\bar{B}N$ component. The calculation also predict the existence of two $S$-wave $\bar{B}N-{\bar{B}}^{\ast }N$ bound states that can be related to the experimentally observed ${\Lambda }_b(5912)$ and ${\Lambda }_b(5920)$.

   hep-phnucl-thEPJA(2023)·6 citations
5. 05*

   Parton energy loss at LHC tests for a strongly coupled medium

   Sourendu Gupta🇮🇳 · Rishi Sharma🇮🇳

   We construct a measure of transverse momentum loss of jets in nuclear collisions at LHC directly using measurements of jet cross sections in PbPb and pp collisions. The proposal is shown to be equivalent to R_AA and is equally straightforward to construct. Using data from the ATLAS collaboration at two different collision energies, we show that the proposed measure has small statistical uncertainties. We argue that systematic errors can be easily improved over our estimates by the experimental collaboration to such an extent that it directly probes whether the jet-medium interaction is due to a strongly interacting medium or a weakly interacting plasma. We argue that the current data may marginally favour a strongly interacting medium. On the other hand, assuming that the medium is weakly interacting, we are able to provide estimates of the jet quenching parameter qhat which are in rough agreement with previously reported estimates.

   hep-phhep-exnucl-exnucl-th0 citations
6. 06*

   $O({\alpha }_s)$ perturbative and nonperturbative corrections to polarized semileptonic ${\Lambda }_b$ decay distributions

   Martin Fischer🇩🇪 · Stefan Groote🇪🇪

   In this paper we calculate first order radiative QCD corrections to the decay process $b\to c{W}^{-}(\to {\ell }^{-}{\bar{\nu }}_{\ell })$ of a polarized bottom quark. Taking into account both the bottom and charm quark masses, the analytical expressions given in this paper allow for a detailed analysis of the differential decay rate of the polarized quark in dependence on the polar and azimuthal angles of the lepton pair and the angle of the polarization vector of the quark relative to the momentum direction of the $W$ boson. The results are given for different polarization states of the charged lepton. In addition, we calculated nonperturbative corrections and estimated their contribution.

   hep-phhep-exPRD(2022)·0 citations
7. 07*

   Trajectories and Radiation of Charged Particles in the Pulsar Magnetosphere

   Shan Chang🇨🇳 · Li Zhang🇨🇳 · Zejun Jiang🇺🇸 · Xiang Li🇨🇳

   Trajectories and radiation of the accelerating electrons are studied in the pulsar magnetosphere approximated as the electromagnetic field of the Deutsch's solutions. Because the electrons are accelerated rapidly to ultra-relativistic velocity near the neutron star surface, the electron velocity vector (and then its trajectory) is derived from the balance between Lorentz force and radiation reaction force, which makes the pitch angle between electron trajectories and magnetic field lines nonzero in most part of the magnetosphere. In such a case, the spectral energy distributions (SEDs) of synchro-curvature radiation for the accelerating electrons with a mono-energetic form are calculated. Our results indicate that: (i) the pitch angle is the function of electron position ($r,\theta ,\varphi$) in the open field line regions, and increases with increasing $r$ and $\theta$ as well as increasing the inclination angle; (ii) the radius of curvature becomes large along the particle trajectory, and (iii) the SED appears a double peak structure depending on the emission position, where the synchrotron radiation plays an important role in X-ray band and curvature radiation mainly works in GeV band, which is only determined by parameters $\alpha$ and $\zeta$

   hep-phastro-ph.HEMNRAS(2022)·3 citations
8. 08*

   Impossibility of obtaining a CP-violating Euler-Heisenberg effective theory from a viable modification of QED

   M. Ghasemkhani🇮🇷 · V. Rahmanpour🇮🇷 · R. Bufalo🇧🇷 · A. Soto🇬🇧

   In this paper, we examine the CP-violating term of the Euler-Heisenberg action. We focus in the aspects related with the generation of such a term from a QED-like model in terms of the effective action approach. In particular, we show that the generation of the CP-violating term is closely related with both of vector and axial fermionic bilinears. Although, these anomalous models are not a "viable" extension of QED, we argue that the CP-violating term in the photon sector is obtained only from this class of models, and not from any fundamental field theory.

   hep-phhep-thEPJC(2022)·3 citations
9. 09*

   Off-forward anomalous dimensions of non-singlet transversity operators

   S. Van Thurenhout🇩🇪

   We determine the anomalous dimension matrix for the transversity operator mixing into total derivative operators in the limit of a large number of quark flavors $n_f$ to fourth order in the strong coupling ${\alpha }_s$ in the $\overline{\text{MS}}$-scheme. This is achieved by using a consistency relation between the operator anomalous dimensions, which follows from the renormalization structure of the operators in the chiral limit.

   hep-phNPB(2022)·7 citations
10. 10*

    On the new and old physics in the interaction of a radiating electron with the extreme electromagnetic field

    M. Jirka🇨🇿 · P. V. Sasorov🇨🇿 · S. V. Bulanov🇨🇿

    We show that an all-optical configuration of the laser-electron collision in the ${\lambda }^3$ configuration based on 10 PW-class lasers presents a viable platform for reaching the range of parameters where a perturbative QED in strong external electromagnetic field breaks. This case is contingently referred to as a case of the nonperturbative QED; and this range of parameters is the intriguing goal from an experimental point of view because of a possible manifestation of a new physics of the interaction of a highly radiating particle with a strong electromagnetic field. We show that the strong field region can be reached by the electrons having the initial energy higher than 50 GeV. Our theoretical considerations are in agreement with three-dimensional particle-in-cell simulations. While increasing of the electron energy raises the number of electrons experiencing the strong field region, the observable signature of photon emission radiative correction in the strong field is expected to fade out when the electron energy surpasses the optimal value. This threshold of electron energy is identified and the parameters for achieving the nonperturbative limit of QED are provided.

    hep-phphysics.plasm-phPRD(2022)·3 citations
11. 11*

    Local and global polarization of $\Lambda$ hyperons across RHIC-BES energies: the roles of spin hall effect, initial condition and baryon diffusion

    Xiang-Yu Wu🇨🇳 · Cong Yi🇨🇳 · Guang-You Qin🇨🇳 · Shi Pu🇨🇳

    We perform a systematic study on the local and global spin polarization of $\Lambda$ and $\overline{\Lambda }$ hyperons in relativistic heavy-ion collisions at beam energy scan energies via the (3+1)-dimensional CLVisc hydrodynamics model with AMPT and SMASH initial conditions. Following the quantum kinetic theory, we decompose the polarization vector as the parts induced by thermal vorticity, shear tensor and the spin Hall effect (SHE). We find that the polarization induced by SHE and the total polarization strongly depends on the initial conditions. At $7.7$GeV, SHE gives a sizeable contribution and even flips the sign of the local polarization along the beam direction for AMPT initial condition, which is not observed for SMASH initial condition. Meanwhile, the local polarization along the out-of-plane direction induced by SHE with AMPT initial condition does not always increase with decreasing collision energies. Next, we find that the polarization along the beam direction is sensitive to the baryon diffusion coefficient, but the local polarization along the out-of-plane direction is not. Our results for the global polarization of $\Lambda$ and $\overline{\Lambda }$ agree well with the STAR data. Interestingly, the global polarization of $\overline{\Lambda }$ is not always larger than that of $\Lambda$ due to various competing effects. Our findings are helpful for understanding the polarization phenomenon and the detailed structure of quark-gluon plasma in relativistic heavy-ion collisions.

    hep-phnucl-exnucl-thPRC(2022)·78 citations
12. 12*

    Capture of Electroweak Multiplet Dark Matter in Neutron Stars

    Motoko Fujiwara🇯🇵 · Koichi Hamaguchi🇯🇵 · Natsumi Nagata🇯🇵 · Jiaming Zheng🇨🇳

    If dark matter has a sizable scattering cross section with nucleons, it can efficiently be captured by a neutron star. Its energy is then transferred to the neutron star as heat through the scattering and annihilation inside the star. This heating effect may be detectable via dedicated temperature observations of nearby old pulsars, providing an alternative method for dark matter searches. In this paper, we show that for electroweak multiplet dark matter this search strategy can probe the parameter region which is out of reach of future dark matter direct detection experiments. To see this systematically, we classify such dark matter candidates in terms of their electroweak charges and investigate the effect of ultraviolet physics by means of higher-dimensional effective operators. We then show that if the effect of ultraviolet physics is sizable, the dark matter-nucleon elastic scattering cross section becomes sufficiently large, whilst if it is suppressed, then the mass splittings among the components of the DM multiplet get small enough so that the inelastic scattering processes are operative. In any case, the electroweak multiplet dark matter particles are efficiently captured in neutron stars, making the search strategy with the temperature observation of old neutron stars promising.

    hep-phhep-exPRD(2022)·36 citations
13. 13*

    Linear power corrections to $e^{+}{e}^{-}$ shape variables in the three-jet region

    Fabrizio Caola🇬🇧 · Silvia Ferrario Ravasio🇬🇧 · Giovanni Limatola🇮🇹 · Kirill Melnikov🇩🇪 · Paolo Nason🇮🇹 · Melih Arslan Ozcelik🇩🇪

    We use an abelian model to study linear power corrections which arise from infrared renormalons and affect event shapes in $e^{+}{e}^{-}$ annihilation into hadrons. While previous studies explored power corrections in the two-jet region, in this paper we focus on the three-jet region, which is the most relevant one for the determination of the strong coupling constant. We show that for a broad class of shape variables, linear power corrections can be written in a factorised form, that involves an analytically-calculable function, that characterises changes in the shape variable when a soft parton is emitted, and a constant universal factor. This universal factor is proportional to the so-called Milan factor, introduced in earlier literature to describe linear power corrections in the two-jet region. We find that the power corrections in the two-jet and in the three-jet regions are different, a result which is bound to have important consequences for the determination of the strong coupling constant from event shapes. As a further illustration of the power of the approach developed in this paper, we provide explicit analytic expressions for the leading power corrections to the $C$-parameter and the thrust distributions in the $N$-jet region for arbitrary $N$, albeit in the abelian model.

    hep-phJHEP(2022)·49 citations
14. 14*

    Three-body molecules $\bar{D}{\bar{D}}^{\ast }{\Sigma }_c$- understanding the nature of $T_{cc}$, $P_c(4312)$, $P_c(4440)$ and $P_c(4457)$

    Ya-Wen Pan🇨🇳 · Tian-Wei Wu🇨🇳 · Ming-Zhu Liu🇨🇳 · Li-Sheng Geng🇨🇳

    The nature of the three pentaquark states, $P_c(4312)$, $P_c(4440)$ and $P_c(4457)$, discovered by the LHCb Collaboration in 2019, is still under debate, although the ${\bar{D}}^{(\ast )}{\Sigma }_c$ molecular interpretation seems to be the most popular. In this work, by adding a $\bar{D}$ meson into the ${\bar{D}}^{\ast }{\Sigma }_c$ pair, we investigate the mass and decay width of the three-body molecules $\bar{D}{\bar{D}}^{\ast }{\Sigma }_c$ and explore the correlation between the existence of the $\bar{D}{\bar{D}}^{\ast }{\Sigma }_c$ molecules with the existence of ${\bar{D}}^{(\ast )}{\Sigma }_c$ and ${\bar{D}}^{\ast }\bar{D}$ two-body molecules. The latter can be identified with the doubly charmed tetraquark state $T_{cc}$ recently discovered by the LHCb Collaboration. Based on the molecular nature of $P_c(4312)$, $P_c(4440)$, $P_c(4457)$, and $T_{cc}$, our results indicate that there exist two three-body bound states of $\bar{D}{\bar{D}}^{\ast }{\Sigma }_c$ with $I(J^P)=1(1/2^{+})$ and $I(J^P)=1(3/2^{+})$, and binding energies $37.24$ MeV and $29.63$ MeV below the $\bar{D}{\bar{D}}^{\ast }{\Sigma }_c$ mass threshold. In addition, we find that the mass splitting of these two three-body molecules are correlated to the mass splitting of $P_c(4440)$ and $P_c(4457)$, which offers a non-trivial way to reveal the molecular nature of these states. The partial widths of two $\bar{D}{\bar{D}}^{\ast }{\Sigma }_c$ molecules decaying into $J/\psi p\bar{D}$ and $J/\psi p{\bar{D}}^{\ast }$ are found to be several MeV. We recommend the experimental searches for the $\bar{D}{\bar{D}}^{\ast }{\Sigma }_c$ molecules in the $J/\psi p\bar{D}$ and $J/\psi p{\bar{D}}^{\ast }$ invariant mass distributions.

    hep-phnucl-thPRD(2022)·16 citations
15. 15*

    Pattern of Global Spin Alignment of $\varphi$ and $K^{\ast 0}$ mesons in Heavy-Ion Collisions

    STAR Collaboration: M. S. Abdallah · B. E. Aboona · J. Adam · L. Adamczyk · J. R. Adams · J. K. Adkins · G. Agakishiev · I. Aggarwal · M. M. Aggarwal · Z. Ahammed · A. Aitbaev · I. Alekseev and 380 other authors

    Notwithstanding decades of progress since Yukawa first developed a description of the force between nucleons in terms of meson exchange, a full understanding of the strong interaction remains a major challenge in modern science. One remaining difficulty arises from the non-perturbative nature of the strong force, which leads to the phenomenon of quark confinement at distances on the order of the size of the proton. Here we show that in relativistic heavy-ion collisions, where quarks and gluons are set free over an extended volume, two species of produced vector (spin-1) mesons, namely $\varphi$ and $K^{\ast 0}$, emerge with a surprising pattern of global spin alignment. In particular, the global spin alignment for $\varphi$ is unexpectedly large, while that for $K^{\ast 0}$ is consistent with zero. The observed spin-alignment pattern and magnitude for the $\varphi$ cannot be explained by conventional mechanisms, while a model with a connection to strong force fields, i.e. an effective proxy description within the Standard Model and Quantum Chromodynamics, accommodates the current data. This connection, if fully established, will open a potential new avenue for studying the behaviour of strong force fields.

    hep-phnucl-exNature(2023)·230 citations
16. 16*

    Anisotropic tomography of heavy quark dissociation by using general propagator structure at finite magnetic field

    Ritesh Ghosh🇮🇳 · Aritra Bandyopadhyay🇨🇳 · Indrani Nilima🇮🇳 · Sabyasachi Ghosh🇮🇳

    In this work we have explored the imaginary part of the Heavy Quark (HQ) potential and subsequently the dissociation of heavy quarkonia at finite temperature and magnetic field. With respect to earlier investigations on this topic, present work contain three new ingredients. First one is considering all Landau level summation, for which present work can be applicable in entire magnetic field domain - from weak to strong. Second one is the general structure of the gauge boson propagator in a hot magnetized medium, which is used here in heavy quark potential problem first time. Third one is a rich anisotropic structure of the complex heavy quark potential, which explicitly depends on the longitudinal and transverse distance. By comparing with earlier references, we have attempted to display our new contributions by plotting heavy quark potential tomography and dissociation probability at finite temperature and magnetic field.

    hep-phnucl-thPRD(2022)·21 citations
17. 17*

    Learning new physics efficiently with nonparametric methods

    Marco Letizia🇮🇹 · Gianvito Losapio🇮🇹 · Marco Rando🇮🇹 · Gaia Grosso🇮🇹 · Andrea Wulzer🇮🇹 · Maurizio Pierini🇨🇭 · Marco Zanetti🇮🇹 · Lorenzo Rosasco🇮🇹

    We present a machine learning approach for model-independent new physics searches. The corresponding algorithm is powered by recent large-scale implementations of kernel methods, nonparametric learning algorithms that can approximate any continuous function given enough data. Based on the original proposal by D'Agnolo and Wulzer (arXiv:1806.02350), the model evaluates the compatibility between experimental data and a reference model, by implementing a hypothesis testing procedure based on the likelihood ratio. Model-independence is enforced by avoiding any prior assumption about the presence or shape of new physics components in the measurements. We show that our approach has dramatic advantages compared to neural network implementations in terms of training times and computational resources, while maintaining comparable performances. In particular, we conduct our tests on higher dimensional datasets, a step forward with respect to previous studies.

    hep-phcs.LGhep-exEPJC(2022)·42 citations
18. 18*

    ee$\in$MC: Simulation of ${\mathbf{e}}^{+}{\mathbf{e}}^{-}\to {\mu }^{+}{\mu }^{-}(\gamma )$ and ${\mathbf{e}}^{+}{\mathbf{e}}^{-}\to {\tau }^{+}{\tau }^{-}(\gamma )$ Events

    Ian M. Nugent🇨🇦

    We present a new Monte-Carlo generator, {\tt ee$\in$MC}, for the simulation of $e^{+}{e}^{-}\to {\mu }^{+}{\mu }^{-}(\gamma )$, $e^{+}{e}^{-}\to {\tau }^{+}{\tau }^{-}(\gamma )$ and $\tau$ lepton decays which is suitable for $e^{+}{e}^{-}$ colliders from threshold up to energy of $\sim 10.58GeV$. The $e^{+}{e}^{-}\to {\mu }^{+}{\mu }^{-}(\gamma )$, $e^{+}{e}^{-}\to {\tau }^{+}{\tau }^{-}(\gamma )$ interactions are computed up to the exact LO matrix element where the running of ${\alpha }_{QED}$ includes both the LO leptonic and hadronic vacuum polarization. Infra-red divergences are investigated within the Yennie-Frautschi-Suura Exponentiation formalism, where several well-known approximations and a formulation based on the exact LO contribution to the soft and virtual photons are applied. The simulation of the $\tau$ lepton consists of the leptonic decay modes at Born level and theoretical models based on Flux-Tube Breaking Models and Chiral Resonance Lagrangian Models as well as experimental models for the majority of semi-leptonic decay modes. This includes hadronic models for investigating the origin of low mass scalar sector recently observed in decays of the $\tau$ lepton and their association with the origin of the constituent-quark mass through Chiral-symmetry Breaking.

    hep-phhep-ex6 citations
19. 19*

    Study of the rare decay $J/\psi \to 2\gamma +hadrons$ at the BESIII

    Feng Zhang🇨🇳 · Jian-Xiong Wang🇨🇳

    Two-photon radiative decay process $J/\psi \to 2\gamma +hadrons$ is studied, and the main contribution processes $J/\psi \to 2\gamma +ggg$ and $J/\psi \to 2\gamma +q\bar{q}$ are calculated. With the specific condition at the BESIII, this rare decay process and the main background process $e^{+}{e}^{-}\to \gamma \gamma +hadrons(q\bar{q})$ are investigated. The results show that the ratio of signal to background can reach 1.24 with the optimized selection criteria at the BESIII. In addition, a few distributions of the signal and background are presented. All the results show that the signal is large enough to be measured in the experiment.

    hep-phCPC(2022)·0 citations
20. 20*

    Heavy quark potential and LQCD based quark condensate at finite magnetic field

    Indrani Nilima🇮🇳 · Aritra Bandyopadhyay🇨🇳 · Ritesh Ghosh🇮🇳 · Sabyasachi Ghosh🇮🇳

    In the present work, we have studied heavy quarkonia potential in hot and magnetized quark gluon plasma. Inverse magnetic catalysis (IMC) effect is incorporated within the system through the magnetic field modified Debye mass by modifying the effective quark masses. We have obtained the real and imaginary part of the heavy quark potential in this new scenario. After the evaluation of the binding energy and the decay width we comment about the dissociation temperatures of the heavy quarkonia in presence of magnetic field.

    hep-phnucl-thEPJC(2023)·17 citations
21. 21*

    Neutron Star Heating in Dark Matter Models for the Muon $g-2$ Discrepancy

    Koichi Hamaguchi🇯🇵 · Natsumi Nagata🇯🇵 · Maura E. Ramirez-Quezada🇯🇵

    The observed value of the muon magnetic dipole moment, which deviates from the Standard Model prediction by $4.2\sigma$, can be explained in models with weakly-interacting massive particles (WIMPs) coupled to muons. However, a considerable range of parameter space of such models will remain unexplored in the future LHC experiments and dark matter (DM) direct searches. In this work we discuss the temperature observation of neutron stars (NSs) as a promising way to probe such models given that WIMPs are efficiently captured by NSs through DM-muon or spin-dependent DM-nucleon scattering. The captured WIMPs eventually annihilate in the star core and heat the NS. This effect can be observed in old NSs as it keeps the NS surface temperature at a few thousand K at most, which is much higher than the predicted values of the standard NS cooling theory for NSs older than $\sim 10^7$ years. We consider two classes of representative models, where the DM couples or does not couple to the Higgs field at tree level, and show that the maximal DM heating is realized in both scenarios.

    hep-phJHEP(2022)·17 citations
22. 22*

    Investigation of the bottom analog of the Zcs(3985) state

    Xuejie Liu🇨🇳 · Dianyong Chen🇨🇳 · Hongxia Huang🇨🇳 · Jialun Ping🇨🇳 · Xiaoyun Chen🇨🇳 · Youchang Yang🇨🇳

    Motivated by the recent discovery of the hidden charm exotic state with strangeness by the BESIII and LHCb Collaborations, we study the $S$ wave strange hidden bottom tetraquark in two kinds of quark models. Both meson-meson and diquark-antidiquark configurations are taken into account. The numerical results indicate that there is no bound state in both quark models. However, several resonance states have been predicted. Three resonance states with $I(J^P)=\frac{1}{2}(0^{+})$ are found, the energy ranges of which are $10479\sim 10550$, $10528\sim 10632$, and $10597\sim 10681$ MeV, respectively. Three resonance states with $I(J^P)=\frac{1}{2}(1^{+})$ are predicted to be located in $10491\sim 10675$, $10502\sim 10679$, and $10522\sim 10723$ MeV, respectively. Moreover, there also exist a resonance with $I(J^P)=\frac{1}{2}(2^{+})$ and the mass is estimated to be $10531\sim 10680$ MeV. All these predicted states in the present work should be accessible for the further experiments in LHCb

    hep-phSCPMA(2023)·9 citations
23. 23*

    Constraints on Multi-Field Inflation from the BOSS Galaxy Survey

    Giovanni Cabass🇺🇸 · Mikhail M. Ivanov🇺🇸 · Oliver H. E. Philcox🇺🇸 · Marko Simonović🇨🇭 · Matias Zaldarriaga🇺🇸

    We use redshift-space galaxy clustering data from the BOSS survey to constrain local primordial non-Gaussianity (LPNG). This is of particular importance due to the consistency relations, which imply that a detection of LPNG would rule out all single-field inflationary models. Our constraints are based on the consistently analyzed redshift-space galaxy power spectra and bispectra, extracted from the public BOSS data with optimal window-free estimators. We use a complete perturbation theory model including all one-loop power spectrum corrections generated by LPNG. Our constraint on the amplitude of the local non-Gaussian shape is $f_{\mathrm{NL}}^{\mathrm{local}}=-33\pm 28$ at 68\%\,CL, yielding no evidence for primordial non-Gaussianity. The addition of the bispectrum tightens the $f_{\mathrm{NL}}^{\mathrm{local}}$ constraints from BOSS by $20\%$, and allows breaking of degeneracies with non-Gaussian galaxy bias. These results set the stage for the analysis of future surveys, whose larger volumes will yield significantly tighter constraints on LPNG.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2022)·194 citations
24. 24*

    Double $J/\psi$ production in pion-nucleon scattering at COMPASS

    G.D. Alexeev · M.G. Alexeev · A. Amoroso · V. Andrieux · V. Anosov · K. Augsten · W. Augustyniak · C.D.R. Azevedo · B. Badelek · M. Ball · J. Barth · R. Beck and 183 other authors

    We present the study of the production of double $J/\psi$ mesons using COMPASS data collected with a 190 GeV/$c$ ${\pi }^{-}$ beam scattering off NH${}_3$, Al and W targets. Kinematic distributions of the collected double $J/\psi$ events are analysed, and the double $J/\psi$ production cross section is estimated for each of the COMPASS targets. The results are compared to predictions from single- and double-parton scattering models as well as the pion intrinsic charm and the tetraquark exotic resonance hypotheses. It is demonstrated that the single parton scattering production mechanism gives the dominant contribution that is sufficient to describe the data. An upper limit on the double intrinsic charm content of pion is evaluated. No significant signatures that could be associated with exotic tetraquarks are found in the double $J/\psi$ mass spectrum.

    ↳ hep-exhep-phPLB(2023)·4 citations
25. 25*

    Investigation of $K^{+}{K}^{-}$ pairs in the effective mass region near $2m_K$

    B. Adeva🇪🇸 · L. Afanasyev🇷🇺 · A. Anania🇮🇹 · S. Aogaki🇷🇴 · A. Benelli🇨🇿 · V. Brekhovskikh🇷🇺 · T. Cechak🇨🇿 · M. Chiba🇯🇵 · P. Chliapnikov🇷🇺 · D. Drijard🇨🇭 · A. Dudarev🇷🇺 · D. Dumitriu🇷🇴 and 44 other authors

    The DIRAC experiment at CERN investigated in the reaction $\mathrm{p}(24\mathrm{GeV}/c)+\mathrm{Ni}$ the particle pairs $K^{+}{K}^{-},{\pi }^{+}{\pi }^{-}$ and $p\bar{p}$ with relative momentum $Q$ in the pair system less than 100 MeV/c. Because of background influence studies, DIRAC explored three subsamples of $K^{+}{K}^{-}$ pairs, obtained by subtracting -- using time-of-flight (TOF) technique -- background from initial $Q$ distributions with $K^{+}{K}^{-}$ sample fractions more than 70\%, 50\% and 30\%. The corresponding pair distributions in $Q$ and in its longitudinal projection $Q_L$ were analyzed first in a Coulomb model, which takes into account only Coulomb final state interaction (FSI) and assuming point-like pair production. This Coulomb model analysis leads to a $K^{+}{K}^{-}$ yield increase of about four at $Q_L=0.5$ MeV/c compared to 100 MeV/c. In order to study contributions from strong interaction, a second more sophisticated model was applied, considering besides Coulomb FSI also strong FSI via the resonances $f_0(980)$ and $a_0(980)$ and a variable distance $r^{\ast }$ between the produced $K$ mesons. This analysis was based on three different parameter sets for the pair production. For the 70\% subsample and with best parameters, $3680\pm 370$ $K^{+}{K}^{-}$ pairs was found to be compared to $3900\pm 410$ $K^{+}{K}^{-}$ extracted by means of the Coulomb model. Knowing the efficiency of the TOF cut for background suppression, the total number of detected $K^{+}{K}^{-}$ pairs was evaluated to be around $40000\pm 10\%$, which agrees with the result from the 30\% subsample. The $K^{+}{K}^{-}$ pair number in the 50\% subsample differs from the two other values by about three standard deviations, confirming -- as discussed in the paper -- that experimental data in this subsample is less reliable.

    ↳ hep-exhep-phPRD(2022)·1 citation
26. 26*

    Calculations of $p(n,\gamma )d$ reaction in chiral effective field theory

    Weijie Du🇺🇸 · Soham Pal🇺🇸 · Mamoon Sharaf🇺🇸 · Peng Yin🇨🇳 · Shiplu Sarker🇺🇸 · Andrey M. Shirokov🇷🇺 · James P. Vary🇺🇸

    We present a calculation of the radiative capture cross section $p(n,\gamma )d$ in the low-energy range, where the $M1$ reaction channel dominates. Employing the LENPIC nucleon-nucleon interaction up to the fifth order (N4LO) that is regularized by the semi-local coordinate space regulators, we obtain the initial and final state wave functions, and evaluate the phase shifts of the scattering state and deuteron properties. We derive the transition operator from the chiral effective field theory up to the next-to-next-to leading order (N2LO), where we also regularize the transition operator using regulators consistent with those of the interactions. We compute the capture cross sections and the results show a converging pattern with the chiral-order expansion of the nucleon-nucleon interaction, where the regulator dependence of the results is weak when higher-order nucleon-nucleon interactions are employed. We quantify the uncertainties of the cross-section results due to the chiral-order truncation. The chirally complete and consistent cross-section results are performed up to N2LO and they compare well with the experiments and other theoretical predictions.

    ↳ nucl-thastro-ph.SRhep-phPRC(2022)·12 citations
27. 27*

    Testing multiflavored ULDM models with SPARC

    Lauren Street🇺🇸 · Nickolay Y. Gnedin🇺🇸 · L.C.R. Wijewardhana🇺🇸

    We perform maximum likelihood estimates (MLEs) for single and double flavor ultralight dark matter (ULDM) models using the Spitzer Photometry and Accurate Rotation Curves (SPARC) database. These estimates are compared to MLEs for several commonly used cold dark matter (CDM) models. By comparing various CDM models we find, in agreement with previous studies, that the Burkert and Einasto models tend to perform better than other commonly used CDM models. We focus on comparisons between the Einasto and ULDM models and analyze cases for which the ULDM particle masses are: free to vary; and fixed. For each of these analyses, we perform fits assuming the soliton and halo profiles are: summed together; and matched at a given radius. When we let the particle masses vary, we find a negligible preference for any particular range of particle masses, within $10^{-25}\text{eV}\le m\le 10^{-19}\text{eV}$, when assuming the summed models. For the matched models, however, we find that almost all galaxies prefer particles masses in the range $10^{-23}\text{eV}\lesssim m\lesssim 10^{-20}\text{eV}$. For both double flavor models we find that most galaxies prefer approximately equal particle masses. We find that the summed models give much larger variances with respect to the soliton-halo (SH) relation than the matched models. When the particle masses are fixed, the matched models give median and mean soliton and halo values that fall within the SH relation bounds, for most masses scanned. When the particle masses are fixed in the fitting procedure, we find the best fit results for the particle mass $m=10^{-20.5}\text{eV}$ (for the single flavor models) and $m_1=10^{-20.5}\text{eV}$, $m_2=10^{-20.2}\text{eV}$ for the double flavor, matched model. We discuss how our study will be furthered using a reinforcement learning algorithm.

    ↳ astro-ph.COastro-ph.GAhep-phPRD(2022)·16 citations
28. 28*

    Unexciting non-Abelian electric fields

    Tanmay Vachaspati🇺🇸

    Electric fields in QED are known to discharge due to Schwinger pair production of charged particles. Corresponding electric fields in non-Abelian theory are known to discharge due to the production of gluons. Yet electric flux tubes in QCD ought to be stable to the production of charged gluons as they confine quarks. We resolve this conundrum by finding electric field configurations in pure non-Abelian gauge theory in which the Schwinger process is absent and the electric field is protected against quantum dissipation. We comment on the implications for QCD flux tubes.

    ↳ hep-thhep-lathep-phPRD(2022)·9 citations
29. 29*

    Optical Spectral Variations of a Large Sample of Fermi Blazars

    Zhang Bing-Kai🇺🇸 · Zhao Xiao-Yun🇨🇳 · Wu Qi🇨🇳

    We have investigated the optical spectral behavior of a large sample of Fermi blazars (40 FSRQs and 13 BL Lacs), and found two new universal optical spectral behaviors. In the low state the optical spectrum gradually becomes softer (steeper) or harder (flatter) but more and more slowly when the brightness increases, and then tends to stable in the high state, which are briefly named the redder-stable-when-brighter (RSWB) and bluer-stable-when-brighter (BSWB) behaviors, respectively. 34 FSRQs and 7 BL Lacs exhibit clear RSWB behavior, and 2 FSRQs and 5 BL Lacs show distinct BSWB behavior, which mean that FSRQs favor more RSWB than BSWB behavior, while BL Lacs have no clear preference among both behaviors. We have put forward a unified nonlinear formula to quantitatively characterize the optical spectral behaviors of FSRQs and BL Lacs, which can fit both kinds of behaviors very well. We argue that the RSWB and BSWB behaviors originate from the same mechanism, and they are the universal optical spectral behaviors for blazars. The frequently observed redder-when-brighter (RWB) and bluer-when-brighter (BWB) trends can be considered to be the approximations of the behaviors of RSWB and BSWB, respectively. The rarely observed stable-when-brighter (SWB) trend can also be viewed as an approximation or a special case of the RSWB or BSWB behavior. We have developed a model with two constant-spectral-index components which can not only explain well both two kinds of optical spectral behaviors, but also successfully interpret the differential behaviors between FSRQs and BL Lacs.

    ↳ astro-ph.HEastro-ph.GAhep-phAstrophys.J.Supp.(2022)·9 citations
30. 30*

    Effect of nucleon effective mass and symmetry energy on the neutrino mean free path in a neutron star

    Parada T. P. Hutauruk🇰🇷 · Hana Gil🇰🇷 · Seung-il Nam🇰🇷 · Chang Ho Hyun🇰🇷

    The Korea-IBS-Daegu-SKKU energy density functional (KIDS-EDF) models, constructed from the perturbative expansion of the energy density in nuclear matter, have been successfully and widely applied in describing the properties of finite nuclei and infinite nuclear matter. In the present work, we extend the applications of the KIDS-EDF models to investigate the implications of the nucleon effective mass and nuclear symmetry energy for the properties of neutron stars (NSs) and neutrino interaction with the NS constituent matter in the linear response approximation (LRA). At fixed neutrino energy and momentum transfer, we analyze the total differential cross section of neutrino, the neutrino mean free path (NMFP), and the NS mass-radius (M-R) relations. Remarkable results are given by the KIDS0-m*87 and SLy4 models, in which $M_n^{\ast }/M\lesssim 1$, and their NMFPs are quite higher in comparison with those obtained from the KIDS0, KIDS-A, and KIDS-B models, which result in $M_n^{\ast }/M\gtrsim 1$. For the KIDS0, KIDS-A, and KIDS-B models, we obtain $\lambda \lesssim R_{\text{NS}}$, indicating that these models could predict the slow NS cooling and neutrino trapping in NSs. In contrast, the KIDS0-m*87 and SLy4 models yield $\lambda \gtrsim R_{\text{NS}}$ and thus we expect faster NS cooling and a small possibility of neutrino trapping within NSs. We also calculate the NMFP as a function of the neutrino energy and the nuclear matter density and find that the NMFP decreases as the density and neutrino energy increase, which is consistent with the result obtained in the Brussels-Montreal Skyrme (BSk17 and BSk18) models at saturation density.

    ↳ nucl-thastro-ph.HEhep-phPRC(2022)·17 citations
31. 31*

    Gravity at the Tip of the Throat

    Bruno Valeixo Bento🇬🇧 · Dibya Chakraborty🇲🇽 · Susha Parameswaran🇬🇧 · Ivonne Zavala🇬🇧

    We study the gravitational signatures that arise from compactifying Type IIB supergravity on a compact space containing a Klebanov-Strassler warped throat. After reviewing the dimensional reduction of the 10d graviton and explicitly obtaining the equations of motion for the 4d tensor $h_{\mu \nu }$, vector $h_{\mu n}$ and scalar $h_{mn}$ modes, we find the masses and wavefunctions of the Kaluza-Klein tower of spin-2 states. We explore how the masses and wavefunctions depend on the balance between the strength of the warping and the size of the bulk, and how these relate to the range and strength of the interactions which correct the Newtonian gravitational potential. By computing the modified Newtonian potential for sources on a brane somewhere along the throat, and applying consistency constraints on the Klebanov-Strassler parameters, we obtain predictions for the phenomenological parameter space. In the case of a fully warped throat, and depending on where the brane is along the throat, these predictions are narrow in range and consistent with current observational and experimental constraints. We also begin an exploration of gravitational wave signatures of KK gravitons in warped throats, finding that strong warping can bring the corresponding frequencies down to the windows of current and proposed experiments.

    ↳ hep-thgr-qchep-phJHEP(2022)·12 citations
32. 32*

    Properties of low-lying charmonia and bottomonia from lattice QCD + QED

    J. Koponen🇩🇪 · B. Galloway🇬🇧 · D. Hatton🇬🇧 · C. T. H. Davies🇬🇧 · G. P. Lepage🇺🇸 · A. T. Lytle🇺🇸

    The precision of lattice QCD calculations has been steadily improving for some time and is now approaching, or has surpassed, the 1% level for multiple quantities. At this level QED effects, i.e. the fact that quarks carry electric as well as color charge, come into play. In this report we will summarise results from the first lattice QCD+QED computations of the properties of ground-state charmonium and bottomonium mesons by the HPQCD Collaboration.

    ↳ hep-lathep-phRev.Mex.Fis.Suppl.(2022)·2 citations
33. 33*

    Elucidation of 'Cosmic Coincidence'

    Meir Shimon🇮🇱

    In the standard cosmological model the dark energy (DE) and nonrelativistic (NR) matter densities are observationally determined to be comparable at the present time, in spite of their greatly different evolution histories. This `cosmic coincidence' enigma -- also referred to as the `why now? problem' -- relies, by its very definition, on the implicit prior expectation for our `typicality' in the cosmic (expanding) spacetime volume. Otherwise, this conundrum does not exist in the first place. It is shown here that this apparent coincidence could be explained as a non-anthropic observational selection effect: for us to be typical observers in the comoving (static) spacetime volume, the cosmic energy budget must contain a non-vanishing DE component. In addition, it is shown that irrespective of the cosmological initial conditions and assuming no `new physics', the Universe is most likely to be observed at a time when the conformal Hubble radius, ${\mathcal{H}}^{-1}$, attains a maximum. The latter takes place at the epoch when ${\rho }_{DE}$ and ${\rho }_m$, the energy densities of DE and NR matter, respectively, are comparable. Specifically, our presumed `typicality' along the conformal timeline, coupled to a few other plausible assumptions, implies that $R\equiv {\rho }_{DE}/{\rho }_m$ is `sampled' from a Beta Prime probability distribution function. A priori 68\% (95\%) confidence range for the ratio is $0.20<R<3.46$ ($0.033<R<17.20$), with an expectation value of $\bar{R}=3.5$. These are in agreement with the observationally inferred value, $R_{obs}=2.23$.

    ↳ astro-ph.COgr-qchep-ph2 citations
34. 34*

    Krylov Complexity in Quantum Field Theory

    Kiran Adhikari🇩🇪 · Sayantan Choudhury🇮🇳 · Abhishek Roy🇮🇳

    In this paper, we study the Krylov complexity in quantum field theory and make a connection with the holographic "Complexity equals Volume" conjecture. When Krylov basis matches with Fock basis, for several interesting settings, we observe that the Krylov complexity equals the average particle number showing that complexity scales with volume. Using similar formalism, we compute the Krylov complexity for free scalar field theory and find surprising similarities with holography. We also extend this framework for field theory where an inverted oscillator appears naturally and explore its chaotic behavior.

    ↳ hep-thcond-mat.stat-mechgr-qchep-ph+1NPB(2023)·91 citations
35. 35*

    Constraints from $\Lambda$ hypernuclei on the $\Lambda NN$ content of the $\Lambda$-nucleus potential

    E. Friedman🇮🇱 · A. Gal🇮🇱

    A depth of $D_{\Lambda }\approx -28$ MeV for the $\Lambda$-nucleus potential was confirmed in 1988 by studying $\Lambda$ binding energies deduced from $({\pi }^{+},K^{+})$ spectra measured across the periodic table. Modern two-body hyperon-nucleon interaction models require additional interaction terms, most likely $\Lambda NN$ three-body terms, to reproduce $D_{\Lambda }$. In this work we apply a suitably constructed $\Lambda$-nucleus density dependent optical potential to binding energy calculations of observed $1s_{\Lambda }$ and $1p_{\Lambda }$ states in the mass range $12\le A\le 208$. The resulting $\Lambda NN$ contribution to $D_{\Lambda }$, about 14 MeV repulsion at symmetric nuclear matter density ${\rho }_0=0.17$ fm${}^{-3}$, makes $D_{\Lambda }$ increasingly repulsive at $\rho \gtrsim 3{\rho }_0$, leading possibly to little or no $\Lambda$ hyperon content of neutron-star matter. This suggests in some models a stiff equation of state that may support two solar-mass neutron stars.

    ↳ nucl-thhep-phnucl-exPLB(2023)·38 citations
36. 36*

    Splitting of elliptic flow in a tilted fireball

    Tribhuban Parida🇮🇳 · Sandeep Chatterjee🇮🇳

    The splitting of elliptic flow measured in different regions of the momentum space of produced hadrons has been recently studied in transport models and proposed as a sensitive probe of the angular momentum carried by the fireball produced in a relativistic heavy ion collision. The initial state angular momentum also gives rise to rapidity odd directed flow which has been measured. We consider a relativistic hydrodynamic framework with the initial matter distribution suitably calibrated to describe the observed directed flow and apply it to study the spilt in the elliptic flow. Our study suggests that the split in the elliptic flow is mostly driven by directed and triangular flows and may be used to constrain models of initial state rapidity distribution of matter in the fireball.

    ↳ nucl-thhep-exhep-phnucl-exPRC(2022)·11 citations
37. 37*

    Proof of a three-loop relation between the Regge limits of four-point amplitudes in N=4 SYM and N=8 supergravity

    Stephen G. Naculich🇺🇸 · Theodore W. Wecker🇺🇸

    A previously proposed all-loop-orders relation between the Regge limits of four-point amplitudes of N=4 supersymmetric Yang-Mills theory and N=8 supergravity is established at the three-loop level. We show that the Regge limit of known expressions for the amplitudes obtained using generalized unitarity simplifies in both cases to a (modified) sum over three-loop ladder and crossed-ladder scalar diagrams. This in turn is consistent with the result obtained using the eikonal representation of the four-point gravity amplitude. A possible exact three-loop relation between four-point amplitudes is also considered.

    ↳ hep-thhep-phJHEP(2022)·1 citation
38. 38*

    Eliminating Primary Beam Effect in Foreground Subtraction of Neutral Hydrogen Intensity Mapping Survey with Deep Learning

    Shulei Ni🇺🇸 · Yichao Li🇺🇸 · Li-Yang Gao🇺🇸 · Xin Zhang🇨🇳

    In the neutral hydrogen (HI) intensity mapping (IM) survey, the foreground contamination on the cosmological signals is extremely severe, and the systematic effects caused by radio telescopes themselves further aggravate the difficulties in subtracting foreground. In this work, we investigate whether the deep learning method, concretely the 3D U-Net algorithm here, can play a crucial role in foreground subtraction when considering the systematic effect caused by the telescope's primary beam. We consider two beam models, i.e., the Gaussian beam model as a simple case and the Cosine beam model as a sophisticated case. The traditional principal component analysis (PCA) method is employed as a comparison and, more importantly, as the preprocessing step for the U-Net method to reduce the sky map dynamic range. We find that in the case of the Gaussian beam, the PCA method can effectively clean the foreground. However, the PCA method cannot handle the systematic effect induced by the Cosine beam, and the additional U-Net method can improve the result significantly. In order to show how well the PCA and U-Net methods can recover the HI signals, we also derive the HI angular power spectra, as well as the HI 2D power spectra, after performing the foreground subtractions. It is found that, in the case of Gaussian beam, the concordance with the original HI map using U-Net is better than that using PCA by $27.4\%$, and in the case of Cosine beam, the concordance using U-Net is better than that using PCA by $144.8\%$. Therefore, the U-Net based foreground subtraction can efficiently eliminate the telescope primary beam effect and shed new light on recovering the HI power spectrum for future HI IM experiments.

    ↳ astro-ph.IMgr-qchep-phApJ(2022)·29 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.