Tue·Feb 28, 2023Tuesday·February 28, 2023

1. 01*

   Generative Invertible Quantum Neural Networks

   Armand Rousselot🇩🇪 · Michael Spannowsky🇬🇧

   Invertible Neural Networks (INN) have become established tools for the simulation and generation of highly complex data. We propose a quantum-gate algorithm for a Quantum Invertible Neural Network (QINN) and apply it to the LHC data of jet-associated production of a Z-boson that decays into leptons, a standard candle process for particle collider precision measurements. We compare the QINN's performance for different loss functions and training scenarios. For this task, we find that a hybrid QINN matches the performance of a significantly larger purely classical INN in learning and generating complex data.

   hep-phcs.AIcs.LGquant-phSciPost Phys.(2024)·9 citations
2. 02*

   Finite volume effects in the extended linear sigma model via low momentum cutoff

   Győző Kovács🇭🇺 · Péter Kovács🇭🇺 · Pok Man Lo🇵🇱 · Krzysztof Redlich🇵🇱 · György Wolf🇭🇺

   Contrary to field theoretical calculations in the thermodynamic limit where the volume is assumed to be infinitely large, the heavy-ion collisions always carry the effects of finite size. A sufficiently small system size is expected to affect the thermodynamic quantities and the phase diagram of the strongly interacting matter. To study these effects one can take into account the finite spatial extent of the system within the framework of an effective model too, via the restriction of the momentum integrals using discretization or in a simplified case using a low momentum cutoff. We investigated the effects of the finite volume in a vector meson extended Polyakov quark-meson model and found a remarkable change in the thermodynamics and the phase transition, especially in the location of the critical endpoint.

   hep-phnucl-thPoS(2023)·5 citations
3. 03*

   Radiative decays of the spin-$2$ partner of $X(3872)$

   Pan-Pan Shi🇨🇳 · Jorgivan M. Dias🇨🇳 · Feng-Kun Guo🇨🇳

   It has been generally expected that the $X(3872)$ has a spin-2 partner, $X_2$, with quantum numbers $J^{PC}=2^{++}$. In the hadronic molecular model, its mass was predicted to be below the $D^{\ast }{\bar{D}}^{\ast }$ threshold, and the new structure reported in the $\gamma \psi (2S)$ invariant mass distribution by the Belle Collaboration with mass $M=(4014.3\pm 4.0\pm 1.5)$ MeV and decay width $\Gamma =(4\pm 11\pm 6)$ MeV, with a global significance of 2.8 $\sigma$, is a nice candidate for it. We consider the radiative decay widths for the $X_2\to \gamma \psi$ with $\psi =J/\psi ,\psi (2S)$ treating the $X_2$ as a $D^{\ast }{\bar{D}}^{\ast }$ shallow bound state, and estimate the events of $X_2$ in two-photon collisions that can be collected in the $\gamma J/\psi \to \gamma {\ell }^{+}{\ell }^{-}$ ($\ell =e,\mu$) final states at Belle. Based on the upper limit for the ratio of decay widths of $X(3872)\to \gamma \psi (2S)$ and $X(3872)\to \gamma J/\psi$ measured by BESIII, we predict the similar ratio $\Gamma (X_2\to \gamma \psi (2S))/\Gamma (X_2\to \gamma J/\psi )$ to be smaller than $1.0$. We suggest searching for the $X_2$ signal in the $\gamma J/\psi$ invariant mass distribution via two-photon fusions. The results will lead to insights into both the $X(3872)$ and the new structure observed by Belle.

   hep-phhep-exnucl-exnucl-thPLB(2023)·19 citations
4. 04*

   Effect of time-varying electromagnetic field on Wiedemann-Franz law in a hot hadronic matter

   Kamaljeet Singh🇮🇳 · Jayanta Dey🇮🇳 · Raghunath Sahoo🇮🇳 · Sabyasachi Ghosh🇮🇳

   We have estimated the electrical and thermal conductivity of a hadron resonance gas for a time-varying magnetic field, which is also compared with constant and zero magnetic field cases. Considering the exponential decay of electromagnetic fields with time, a kinetic theory framework can provide the microscopic expression of electrical and thermal conductivity in terms of relaxation and decay times. In the absence of the magnetic field, only a single time scale appears, and in the finite magnetic field case, their expressions carry two-time scales, relaxation time and cyclotron time period. Estimating the conductivities for HRG matter in three cases -- zero, constant, and time-varying magnetic fields, we have studied the validity of the Wiedemann-Franz law. We noticed that at a high-temperature domain, the ratio saturates at a particular value, which may be considered as Lorenz number of the hadron resonance gas. With respect to the saturation values, the deviation of the Wiedemann-Franz law has been quantified at the low-temperature domain. For the first time, the present work sketches this quantitative deviation of the Wiedemann-Franz law for hadron resonance gas at a constant and a time-varying magnetic field.

   hep-phhep-exnucl-exnucl-thPRD(2023)·23 citations
5. 05*

   Production and decay of polarized hyperon-antihyperon pairs

   Karin Schönning🇸🇪 · Varvara Batozskaya🇨🇳 · Patrik Adlarson🇸🇪 · Xiaorong Zhou🇨🇳

   Polarized hyperon-antihyperon pairs shed light on various unresolved puzzles in contemporary physics: How the strong interaction confines quarks into hadrons, how accurately the Standard Model describes microcosmos and even why our universe consists of so much more matter than antimatter. Thanks to their weak, parity violating decays, hyperons reveal their spin properties. This can be exploited e.g. the decomposition of the electromagnetic structure of hyperons, precision tests of flavour symmetry and searches for CP violation. At the BESIII experiment at BEPC-II, Beijing, China, hyperon-antihyperon pairs can be produced in abundance. Recently collected large data samples have triggered the development of new methods that provide unprecedented precision and a plethora of new results have emerged. When applied at future high-intensity facilities like PANDA and STCF, precision physics will be taken to a new level which can contribute to the solution to the aforementioned puzzles.

   hep-phhep-exCPC(2023)·14 citations
6. 06*

   New type of hydrogenlike charm-pion or charm-kaon matter

   Si-Qiang Luo🇨🇳 · Zhan-Wei Liu🇨🇳 · Xiang Liu🇨🇳

   Borrowing the structures of the hydrogen atom, molecular ion, and diatomic molecule, we predict the nature of a new type of hydrogenlike charm-pion or charm-kaon matter that could be obtained by replacing the proton and electron in hydrogen matter with a charmed meson and a pion or a kaon, respectively. We find that the spectra of the atom, molecular ion, and diatomic molecule can be obtained simultaneously with the Coulomb potential for the hydrogen, the charm-pion, and the charm-kaon systems. The predicted charm-pion matter also allows us to explore the mass shift mediated by the strong interaction. For the charm-pion and charm-kaon systems, the strong interactions could lead to binding energy shifts. Our calculations suggests that the binding energy shifts in charm-pion systems are in the order of several to tens of eV. For the charm-kaon systems, the results are in the order of tens to hundreds of eV. Exploring hydrogenlike charm-pion matter must lead to new demands for high-precision experiments.

   hep-phhep-exnucl-exnucl-thPRD(2023)·7 citations
7. 07*

   The leptonic di-flavor and di-number violation processes at high energy ${\mu }^{\pm }{\mu }^{\pm }$ colliders

   Jin-Lei Yang🇨🇳 · Chao-Hsi Chang🇨🇳 · Tai-Fu Feng🇨🇳

   The leptonic di-flavor violation (LFV) processes ${\mu }^{\pm }{\mu }^{\pm }\to e^{\pm }{e}^{\pm }$, ${\mu }^{\pm }{\mu }^{\pm }\to {\tau }^{\pm }{\tau }^{\pm }$ and the leptonic di-number violation (LNV) processes ${\mu }^{\pm }{\mu }^{\pm }\to W_i^{\pm }{W}_j^{\pm }$ ($i,j=1,2$) at the same-sign high energy ${\mu }^{\pm }{\mu }^{\pm }$ colliders are studied. The new physics (NP) factors that may play roles in these processes are highlighted by cataloging them into three types. Taking into account the experimental constraints, the processes at ${\mu }^{\pm }{\mu }^{\pm }$ colliders are computed and the results are presented properly. The results lead to the conclusion that observing the NP factors through the LFV and LNV processes at TeV-energy ${\mu }^{\pm }{\mu }^{\pm }$ colliders has significant advantages that cannot be achieved elsewhere. Therefore, in developing the techniques of muon acceleration and collisions, the option of building the same-sign muon high-energy colliders should be considered seriously too.

   hep-phCPC(2024)·26 citations
8. 08*

   Schwinger Pair Production in QCD from Flavor-Dependent Contact Interaction Model of Quarks

   Aftab Ahmad🇵🇰 · Akif Farooq🇵🇰

   We study the Schwinger mechanism in QCD i.e., the quark-antiquark pair production rate $\Gamma$ in the presence of pure electric field strength $eE$, for a higher number of colors $N_c$ and flavors $N_f$. In this context, our unified formalism is based on the Schwinger-Dyson equations, flavor-dependent symmetry preserving vector-vector contact interaction model of quarks, and an optimal time regularization scheme. For fixed $N_c=3$ and $N_f=2$, the dynamically quark mass decreases as we increase $eE$ and near at and above the pseudo-critical electric field $e{E}_c$, the chiral symmetry is restored and quarks becomes unconfined. The pair production rate $\Gamma$ becomes stable and grows quickly above $e{E}_c$. For fixed $N_c=3$ and upon increasing $N_f$ the dynamical mass suppresses and as a result, the $e{E}_c$ reduces to its smaller values, the pair production rate $\Gamma$ tends to initiates and grows quickly for smaller values of $e{E}_c$. In contrast, for fixed $N_f=2$ and upon increasing $N_c$, the dynamical chiral symmetry is restored for larger and larger values of $e{E}_c$ and at $N_c\ge 4$, the transition changes from smooth cross-over to the first order at some critical endpoint ($N_{c,p},e{E}_{c,p}$). Consequently, the quark-antiquark production rate $\Gamma$ needs higher values of $e{E}_c$ for the stable and quick growth as we increase $N_c$. Our findings are satisfactory and in agreement with already predicted results for pair production rate (for fixed $N_c=3$ and $N_f=2$) by other reliable effective models of QCD.

   hep-phBraz.J.Phys.(2024)·8 citations
9. 09*

   Radiative Meson and Glueball Decays in the Witten-Sakai-Sugimoto Model

   Florian Hechenberger🇦🇹 · Josef Leutgeb🇦🇹 · Anton Rebhan🇦🇹

   We calculate radiative decay rates of mesons and glueballs in the top-down holographic Witten-Sakai-Sugimoto model with finite quark masses. After assessing to what extent this model agrees or disagrees with experimental data, we present its predictions for so far undetermined decay channels. Contrary to widespread expectations, we obtain sizeable two-photon widths of scalar, tensor, and pseudoscalar glueballs, suggesting in particular that the observed two-photon rate of the glueball candidate $f_0(1710)$ is not too large to permit a glueball interpretation, but could be even much higher. We also discuss the so-called exotic scalar glueball, which in the Witten-Sakai-Sugimoto model is too broad to match either of the main glueball candidates $f_0(1500)$ and $f_0(1710)$, but might be of interest with regard to the alternative scenario of the so-called fragmented scalar glueball. Employing the exotic scalar glueball for the latter, much smaller two-photon rates are predicted for the ground-state glueball despite a larger total width; relatively large two-photon rates would then apply to the excited scalar glueball described by the predominantly dilatonic scalar glueball. In either case, the resulting contributions to the muon $g-2$ from hadronic light-by-light scattering involving glueball exchanges are small compared to other single meson exchanges, of the order of $\lesssim 10^{-12}$.

   hep-phPRD(2023)·22 citations
10. 10*

    Automatic detection of boosted Higgs boson and top quark jets in an event image

    Sang Kwan Choi🇨🇳 · Jinmian Li🇨🇳 · Cong Zhang🇨🇳 · Rao Zhang🇨🇳

    We build a deep neural network based on the Mask R-CNN framework to detect the Higgs jets and top quark jets in any event image. We propose an algorithm to assign the top quark final states at the ground truth level so that the network can be trained in a supervised manner. A new jet branch is added to the network, which uses constituent information to predict the four-momenta of the original parton, thus intrinsically implementing the pileup mitigation. The network can predict both the shapes and the momenta of target jets. We show that the network surpasses the LorentzNet in top and Higgs tagging and the PELICAN network in momentum regression for certain cases, in terms of reconstruction efficiency and accuracy. We also show that the performance of the network does not degrade much when applied to events of a process different from the trained one and to events with overlapping jets.

    hep-phhep-exPRD(2023)·11 citations
11. 11*

    Gravitational waves from first-order phase transition in an electroweakly interacting vector dark matter model

    Tomohiro Abe🇯🇵 · Katsuya Hashino🇯🇵

    We discuss gravitational waves in an electroweakly interacting vector dark matter model. In the model, the electroweak gauge symmetry is extended to SU(2)${}_0\times$ SU(2)${}_1\times$SU(2)${}_2\times$ U(1)${}_Y$ and spontaneously broken into SU(2)${}_L\times$ U(1)${}_Y$ at TeV scale. The model has an exchange symmetry between SU(2)${}_0$ and SU(2)${}_2$. This symmetry stabilizes some massive vector bosons associated with the spontaneous symmetry breaking described above, and an electrically neutral one is a dark matter candidate. In the previous study, it was found that the gauge couplings of SU(2)${}_0$ and SU(2)${}_1$ are relatively large to explain the measured value of the dark matter energy density via the freeze-out mechanism. With the large gauge couplings, the gauge bosons potentially have a sizable effect on the scalar potential. In this paper, we focus on the phase transition of SU(2)${}_0\times$ SU(2)${}_1\times$ SU(2)${}_2\to$ SU(2)${}_L$. We calculate the effective potential at finite temperature and find that the phase transition is first-order and strong in a wide range of the parameter space. The strong first-order phase transition generates gravitational waves. We calculate the gravitational wave spectrum and find that it is possible to detect the gravitational waves predicted in the model by future space-based gravitational wave interferometers. We explore the regions of the parameter space probed by the gravitational wave detection. We find that the gravitational wave detection can probe the region where the mass of $h^{\prime }$, a CP-even scalar in the model, is a few TeV.

    hep-phPTEP(2024)·12 citations
12. 12*

    Study of jet substructure modification by differential girth at the LHC

    Si-Yu Tang🇨🇳 · Wei Zhang🇨🇳 · Wen-Di Deng🇨🇳 · Cheng-De Tian🇨🇳 · Fan Yang🇨🇳 · Ren-Zhuo Wan🇨🇳

    Jet substructure observables are crucial for exploring the effects of the hot, dense medium and differentiating between quark and gluon jets. In this paper, we investigate the modification of jet shape by calculating the differential girth at LHC energies, ranging from pp to Pb--Pb collisions. The differential girth distribution exhibits a wave-like pattern, which offers a better explanation for the radial spreading of jet energy and large-angle radiation effects. We fit the differential girth distribution with a sine wave function to obtain the amplitude, angular frequency, initial phase, and offset distance parameters as a function of jet radius. The results clearly differentiate between pp and heavy-ion collisions, with varying dependencies on centrality and collision energy. Our findings shed new light on the understanding of radial jet energy loss in the QGP (quark-gluon plasma) medium, and provide additional potential observables for measuring jet shape at the LHC in the future.

    hep-ph1 citation
13. 13*

    Real and virtual photons within basis light-front quantization

    Sreeraj Nair🇨🇳 · Chandan Mondal🇨🇳 · Xingbo Zhao🇨🇳 · Asmita Mukherjee🇮🇳 · James P. Vary🇺🇸

    We compute the structure function, transverse momentum dependent parton distributions (TMDs), and generalized parton distributions (GPDs) for the physical photon from the light-front quantum electrodynamics (QED) Hamiltonian, determined for its constituent bare photon and electron-positron Fock components within the Basis Light-Front Quantization framework. After performing nonperturbative renormalization, we obtain a good quality description of the perturbative QED properties of the photon, as well as good agreement with the experimental data for the photon's structure function. We also investigate the TMDs and GPDs of the space-like and the time-like virtual photon by incorporating a nonzero photon mass.

    hep-phPRD(2023)·12 citations
14. 14*

    Three-particle distribution in B meson and charm-quark loops in FCNC B decays

    Dmitri Melikhov🇷🇺

    We discuss a nonfactorizable (NF) contribution of a charm loop to the FCNC $B$-decay amplitude given through the three-particle Bethe-Salpeter amplitude (3BS) of the $B$-meson. This 3BS contains one heavy-quark field and two light fields (a light quark and a gluon). Our discussion is aimed at clarifying properties of the $B$-meson 3BS necessary to describe properly charm-loop contributions to the amplitudes of FCNC $B$-decays. We demonstrate that the dominant contribution of nonfactorizable charm to FCNC $B$-decay amplitude is given in the heavy-quark limit by a convolution of some hard kernel and the $B$-meson 3BS in a "double-collinear" light cone (LC) configuration: one of the light degrees of freedom $\varphi (x)$, $x^2=0$, lies on the $(+)$-direction of the LC, whereas another light degree of freedom ${\varphi }^{\prime }(x^{\prime })$, $x^{\prime 2}=0$ lies on the $(-)$-direction. We show the emergence of new constraints on the distribution amplitudes which parametrize the 3BS in this double-collinear configuration.

    hep-phPRD(2023)·7 citations
15. 15*

    Accommodating Hints of New Heavy Scalars in the Framework of the Flavor-Aligned Two-Higgs-Doublet Model

    Joseph M. Connell🇺🇸 · Pedro Ferreira🇵🇹 · Howard E. Haber🇺🇸

    Searches for new neutral Higgs bosons of an extended Higgs sector at the LHC can be interpreted in the framework of the two-Higgs doublet model. By employing generic flavor-aligned Higgs-fermion Yukawa couplings, we propose an analysis that uses experimental data to determine whether flavor alignment is a consequence of a symmetry that is either exact or at most softly broken. We illustrate our proposal in two different scenarios based on a few 3 sigma (local) excesses observed by the ATLAS and CMS Collaborations in their searches for heavy scalars. In Scenario 1, an excess of events is interpreted as $A\to ZH\to {\ell }^{+}{\ell }^{-}b\bar{b}$ (where $\ell =e$ or $\mu$), with the CP-odd and CP-even neutral scalar masses given by $m_A=610$ GeV and $m_H=290$ GeV, respectively. In Scenario 2, an excess of events in the production of $t\bar{t}$ and ${\tau }^{+}{\tau }^{-}$ final states is interpreted as decays of a CP-odd scalar of mass $m_A=400$ GeV. Scenario 1 is consistent with Type-I Yukawa interactions, which can arise in a 2HDM subject to a softly-broken ${\mathbb{Z}}_2$ discrete symmetry. Scenario 2 is inconsistent with a symmetry-based flavor alignment, but can be consistent with more general flavor-aligned Higgs-fermion Yukawa couplings.

    hep-phPRD(2023)·14 citations
16. 16*

    Resurgence analysis of the Adler function at order $1/N_f^2$

    Eric Laenen🇳🇱 · Coenraad Marinissen🇳🇱 · Marcel Vonk🇳🇱

    We compute non-perturbative contributions to the Adler function, the derivative of the vacuum polarization function in gauge theory, using resurgence methods and Borel-summed gauge field propagators. At 2-loop, to order $1/N_f$, we construct the full 2-parameter transseries and perform the sum over the non-perturbative sectors. We then introduce a convolution-based method to derive the transseries structure of product series, which can also be used to study higher orders in the expansion in $1/N_f$. We compute 3-loop planar diagrams, at order $1/N_f^2$, and for each diagram study the asymptotic behavior and resulting non-perturbative information in the transseries. A structure emerges that, from a resurgence point of view, is quite different from toy models hitherto studied. We study in particular the first and second non-perturbative sectors, their relation to UV and IR renormalons, and how their presence influences the perturbative expansions in neighbouring sectors. Finally, finding that many non-perturbative sectors have asymptotic series, we derive relations among all of them, thus providing an interesting new perspective on the alien lattice for the Adler function.

    hep-phhep-thmath-phmath.MPJHEP(2023)·12 citations
17. 17*

    Isolated photon production in $pp$ collisions at forward rapidities and high multiplicity events

    Yuri N. Lima🇧🇷 · André V. Giannini🇧🇷 · Victor P. Goncalves🇧🇷

    The production of isolated photons in high multiplicity events is investigated considering the Color Glass Condensate (CGC) formalism. The associated cross-section for proton - proton collisions is estimated considering three distinct solutions of the Balitsky - Kovchegov (BK) equation and predictions for the normalized photon yield as a function of the multiplicities of co - produced charged particles are presented. We predict the increasing of the yield with the multiplicity, with the slope being smaller for larger rapidities. As the isolated photon production is not affected by the fragmentation process, a future experimental investigation of this process in current high energy hadronic colliders is ideal to test the treatment of high multiplicity events using the CGC formalism, previously applied only for the production of hadronic final states.

    hep-phhep-exnucl-exnucl-thEPJA(2024)·7 citations
18. 18*

    $B_c^{-}\to J/\psi (\to {\mu }^{+}{\mu }^{-}){\tau }^{-}(\to {\pi }^{-}{\nu }_{\tau },{\rho }^{-}{\nu }_{\tau },{\ell }^{-}{\bar{\nu }}_{\ell }{\nu }_{\tau }){\bar{\nu }}_{\tau }$ decays with visible final-state kinematics

    Xin-Qiang Li🇨🇳 · Xin Xu🇨🇳 · Ya-Dong Yang🇨🇳 · Dong-Hui Zheng🇨🇳

    The semitauonic $B_c^{-}\to J/\psi {\tau }^{-}{\bar{\nu }}_{\tau }$ decay is optimal to scrutinize possible new physics effects in $b\to c{\tau }^{-}{\bar{\nu }}_{\tau }$ transitions as indicated by the current data on $R(D^{(\ast )})$ anomalies. In this work, we study the $B_c^{-}\to J/\psi {\tau }^{-}{\bar{\nu }}_{\tau }$ decay with both polarized $\tau$ and $J/\psi$. Their subsequent decays, with $J/\psi \to {\mu }^{+}{\mu }^{-}$ as well as ${\tau }^{-}\to {\pi }^{-}{\nu }_{\tau }$, ${\tau }^{-}\to {\rho }^{-}{\nu }_{\tau }$ and ${\tau }^{-}\to {\ell }^{-}{\bar{\nu }}_{\ell }{\nu }_{\tau }$, are exploited to extract the energy and angular distributions of the charged final-state particles in the processes. Starting with the most general effective Hamiltonian relevant for the $b\to c{\tau }^{-}{\bar{\nu }}_{\tau }$ transitions, including all possible Lorentz structures of the dimension-six operators with both left- and right-handed neutrinos, we first derive the five-fold differential decay rate in terms of the visible final-state kinematics. From this distribution, we then construct in total 34 normalized observables, among which nine refer to the CP-violating triple product asymmetries that vanish within the Standard Model. We also construct five new observables based on the combinations of these normalized observables that can only be attributed to the right-handed neutrinos. On the other hand, considering the low statistics of the fully differential distribution, we introduce some integrated observables with only one kinematic variable left, which are more promising to be measured due to the largely increased statistics. The sensitivities of all these observables to the different new physics scenarios are investigated in detail. Finally, assuming an ideal circumstance, we give an estimate of the statistical uncertainties of the nine CP-conserving observables at LHCb and found that ${\tau }^{-}\to {\pi }^{-}{\nu }_{\tau }$ has the highest analyzing power among the three $\tau$ decay channels.

    hep-phhep-exJHEP(2023)·6 citations
19. 19*

    About Fractional Analytic QCD

    A.V. Kotikov🇷🇺 · I.A. Zemlyakov🇷🇺

    We present a brief overview of fractional analytic QCD, basically following the results recently obtained in Refs. [1,2].

    hep-ph7 citations
20. 20*

    Mixing effects of $\eta -{\eta }^{\prime }$ in ${\Lambda }_b\to \Lambda {\eta }^{{(}^{\prime })}$ decays

    Zhou Rui🇨🇳 · Jia-Ming Li🇨🇳 · Chao-Qi Zhang🇨🇳

    We perform a thorough analysis of the $\eta -{\eta }^{\prime }$ mixing effects on the ${\Lambda }_b\to \Lambda {\eta }^{{(}^{\prime })}$ decays based on the perturbative QCD (PQCD) factorization approach. Branching ratios, up-down and direct $CP$ asymmetries are computed by considering four popular mixing schemes, such as $\eta -{\eta }^{\prime }$, $\eta -{\eta }^{\prime }-{\eta }_c$, $\eta -{\eta }^{\prime }-G$, and $\eta -{\eta }^{\prime }-G-{\eta }_c$ mixing formalism, where $G$ represents the physical pseudoscalar gluball. The PQCD predictions with the four mixing schemes does not change much for the $\eta$ channel but changes significantly for the ${\eta }^{\prime }$ one. In particular, the value of $\mathcal{B}({\Lambda }_b\to \Lambda {\eta }^{{}^{\prime }})$ in the $\eta -{\eta }^{\prime }-G-{\eta }_c$ mixing scheme exceeds the present experimental bound by a factor of 2, indicates the related mixing angles may be overestimated. Because of the distinctive patterns of interference between $S$-wave and $P$-wave amplitudes, the predicted up-down asymmetries for the two modes differ significantly. The obvious discrepancies among different theoretical analyses should be clarified in the future. The direct $CP$ violations are predicted to be at the level of a few percent mainly due to the tree contributions of the strange and nonstrange amplitudes suffer from the color suppression and CKM suppression. Finally, as a byproduct, we investigate the ${\Lambda }_b\to \Lambda {\eta }_c$ process, which has a large branching ratio of order $10^{-4}$, promising to be measured by the LHCb experiment. Our findings are useful for constraining the mixing parameters, comprehending the ${\eta }^{{(}^{\prime })}$ configurations, and instructing experimental measurements.

    hep-phPRD(2023)·4 citations
21. 21*

    Modular J-PET with Improved o-Ps Detection Efficiency for CPT Tests

    Neha Chug🇵🇱 · Aleksander Gajos🇵🇱

    J-PET is a photon detector built of plastic scintillators, which already has been commissioned for CPT studies in the decays of positronium. In the first experiment, J-PET has achieved a sensitivity to CPT violation at a level of 10^{-4}, and now it aims to reach a level of 10^{-5}. This will be done by enhancing the three-photon registration efficiency for ortho-positronium decays using a new layer of densely packed plastic scintillators termed Modular J-PET. We present the simulation studies performed for different experimental detection setups to be used for the next CPT test with the Modular J-PET detector.

    hep-phhep-exnucl-exphysics.ins-det2 citations
22. 22*

    A scheme to fix multiple solutions in amplitude analyses

    Yuanning Gao🇨🇳 · Tianze Rong🇨🇳 · Zhenwei Yang🇨🇳 · Chenjia Zhang🇨🇳 · Yanxi Zhang🇨🇳

    Decays of unstable heavy particles usually involve the coherent sum of several amplitudes, like in a multiple slit experiment. Dedicated amplitude analysis techniques have been widely used to resolve these amplitudes for better understanding of the underlying dynamics. For special cases, where two spin-1/2 particles and two (pseudo-)scalar particles are present in the process, multiple equivalent solutions are found due to intrinsic symmetries in the summed probability density function. In this paper, the problem of multiple solutions is discussed and a scheme to overcome this problem is proposed by fixing some free parameters. Toys are generated to validate the strategy. A new approach to align helicities of initial- and final-state particles in different decay chains is also introduced.

    hep-phhep-exCPC(2024)·3 citations
23. 23*

    The Spectrum of Low-$p_T$ $J/\psi$ in Heavy-Ion Collisions in a Statistical Two-Body Fractal Model

    Huiqiang Ding🇨🇳 · Luan Cheng🇨🇳 · Tingting Dai🇨🇳 · Enke Wang🇨🇳 · Wei-Ning Zhang🇨🇳

    We establish a statistical two-body fractal (STF) model to study the spectrum of $J/\psi$. $J/\psi$ serves as a reliable probe in heavy-ion collisions. The distribution of $J/\psi$ in hadron gas is influenced by flow, quantum and strong interaction effects. Previous models have predominantly focused on one or two of these effects while neglecting the others, resulting in the inclusion of unconsidered effects in the fitted parameters. Here, we study the issue from a new point of view by analyzing the fact that all three effects induce a self-similarity structure, involving a $J/\psi$-$\pi$ two-meson state and a $J/\psi$, $\pi$ two-quark state, respectively. We introduce modification factor $q_{TBS}$ and $q_2$ into the probability and entropy of charmonium. $q_{TBS}$ denotes the modification of self-similarity on $J/\psi$, $q_2$ denotes that of self-similarity and strong interaction between \emph{c }and $\bar{c}$ on quarks. By solving the probability and entropy equations, we derive the values of $q_{TBS}$ and $q_2$ at various collision energies and centralities. Substituting the value of $q_{TBS}$ into distribution function, we successfully obtain the transverse momentum spectrum of low-$p_T$ $J/\psi$, which demonstrates good agreement with experimental data. The STF model can be employed to investigate other mesons and resonance states.

    hep-phnucl-thEntropy(2023)·2 citations
24. 24*

    Charmonium production in a thermalizing heat bath

    Taesoo Song🇩🇪 · Joerg Aichelin🇫🇷 · Elena Bratkovskaya🇩🇪

    Using the Remler formalism for the creation of composed particles, we study charmonium production both in thermalized and thermalizing boxes, which contain charm and anticharm quarks. The thermalizing box studies include the lowering of the box temperature, the spatial diffusion of charm and anticharm quarks, which are initially confined in the central region, as well as the combination of both, what imitates heavy-ion collisions. Comparing numerical and analytical results we demonstrate that the rate of the original Remler formalism has to be supplemented by two rates to obtain, for $t\to \infty$, results, which are consistent with the statistical model predictions: i) a rate, which takes into account the temperature dependence of the Wigner density of the quarkonium during the expansion and, in the case that a heavy quark potential is not implemented in the Monte Carlo approach, ii) a rate which comes from the change of the relative distance between the heavy quark and antiquark. These results provide the basis for future applications of the Remler formalism to heavy-ion collisions.

    hep-phnucl-thPRC(2023)·10 citations
25. 25*

    Quark mass dependence of the low-lying charmed mesons at one loop in HH$\chi$PT

    F. Gil-Domínguez🇪🇸 · R. Molina🇪🇸

    We study the light and heavy quark mass dependence of the low-lying charmed mesons in the framework of one-loop HH$\chi$PT. The low energy constants are determined by analyzing the available lattice data from different LQCD simulations. Model selection tools are implemented to determine the relevant parameters as required by data with a higher precision. Discretization and other effects due to the charm quark mass setting are discussed.

    ↳ hep-lathep-phPLB(2023)·7 citations
26. 26*

    Prospects of Searches for Anomalous Hadronic Higgs Boson Decays at the LHeC

    Subhasish Behera🇩🇪 · Manuel Hageluken🇩🇪 · Matthias Schott🇩🇪

    The future Large Hadron Electron Collider (LHeC) would enable collisions of an intense electron beam with either protons or heavy ions at the High Luminosity-Large Hadron Collider (HL- LHC). With a center of mass energy greater than a TeV and a high luminosity, the LHeC would be a new-generation collider for deep-inelastic scattering (DIS) and a significant facility for precise Higgs physics, complementing pp and electron-positron colliders. Anomalous hadronic decay signatures of the Higgs Boson, such as those into three or more partons, are challenging to detect at the LHC due to high background rates, but they may be observable at the LHeC. This paper presents the expected sensitivity of the LHeC for the decay channels $H\to 3jets$ and $H\to 4jets$, assuming an integrated luminosity of 1 ab${}^{-1}$. Our analysis indicates that upper limits on the branching ratio of the Higgs Boson of 0.35 and 0.17 at 95% confidence limit for these processes are possible.

    ↳ hep-exhep-ph0 citations
27. 27*

    A Bouncing Cosmology from VECROs

    Robert Brandenberger🇨🇦 · Gabrielle A. Mitchell (McGill University)🇨🇦

    We argue that, in the same way that in a black hole space-time VECROs will form in order to cancel the gravitational effects of a collapsing mass shell and prevent the formation of a singularity, in a contracting universe a gas of VECROs will form to hold up the contraction, prevent a Big Crunch singularity, and lead to a nonsingular cosmological bounce.

    ↳ hep-thastro-ph.COgr-qchep-phEPJC(2023)·6 citations
28. 28*

    A Time Projection Chamber to Search for Feebly Interacting Bosons via Proton Induced Nuclear Reactions

    Martin Sevior🇦🇺 · Michael Baker🇦🇺 · Lindsey Bignell🇦🇺 · Catalina Curceanu🇮🇹 · Jackson T.H. Dowie🇦🇺 · Tibor Kibedi🇦🇺 · David Jamieson🇦🇺 · Andrew Stuchbery🇦🇺 · Andrea Thamm🇦🇺 · Martin White🇦🇺

    We propose a new Time Projection Chamber particle detector (TPC) to search for the existence of feebly-interacting bosons and to investigate the existence of the X17 boson, proposed by the ATOMKI group to explain anomalous results in the angular distributions of electron-positron pairs created in proton-induced nuclear reactions. Our design will provide 200 times greater sensitivity than ATOMKI and the program of research will also provide world-leading limits on feebly interacting bosons in the mass range of 5 - 25 MeV.

    ↳ hep-exhep-ph4 citations
29. 29*

    Practicing carpe diem in the journey of studying physics: A brief review of the scientific contribution of Ru-Keng Su

    Shaoyu Yin🇨🇳 · Wei-Liang Qian🇨🇳 · Ping Wang🇨🇳 · Bin Wang🇨🇳 · Rong-Gen Cai🇨🇳

    We briefly review the scientific contributions of the late Prof. Ru-Keng Su in his academic life. In the area of intermediate and high-energy nuclear physics, Su explored various topics in high-energy nuclear physics and particle physics, inclusively about the finite temperature field theory, effective models for nuclear and quark matter, soliton, and quasiparticle models, among others. In gravity and cosmology, Su's research primarily embraces black hole thermodynamics, quasinormal modes, cosmological microwave background radiation, modified theories of gravity, and AdS/CFT correspondence and its applications. Besides, many aspects of Su's distinguished impact on the Chinese academic physics community are discussed. We also summarize the biographical and academic career of Su. This article is an elaborated version of the memorial article that will be published in \href{https://www.mdpi.com/journal/symmetry}{\it symmetry}.

    ↳ physics.hist-phhep-phnucl-th0 citations
30. 30*

    Thin and thick bubble walls I: vacuum phase transitions

    Ariel Mégevand🇦🇷 · Federico Agustín Membiela🇦🇷

    This is the first in a series of papers where we study the dynamics of a bubble wall beyond usual approximations, such as the assumptions of spherical bubbles and infinitely thin walls. In this paper, we consider a vacuum phase transition. Thus, we describe a bubble as a configuration of a scalar field whose equation of motion depends only on the effective potential. The thin-wall approximation allows obtaining both an effective equation of motion for the wall position and a simplified equation for the field profile inside the wall. Several different assumptions are involved in this approximation. We discuss the conditions for the validity of each of them. In particular, the minima of the effective potential must have approximately the same energy, and we discuss the correct implementation of this approximation. We consider different improvements to the basic thin-wall approximation, such as an iterative method for finding the wall profile and a perturbative calculation in powers of the wall width. We calculate the leading-order corrections. Besides, we derive an equation of motion for the wall without any assumptions about its shape. We present a suitable method to describe arbitrarily deformed walls from the spherical shape. We consider concrete examples and compare our approximations with numerical solutions. In subsequent papers, we shall consider higher-order finite-width corrections, and we shall take into account the presence of the fluid.

    ↳ gr-qcastro-ph.COhep-phJCAP(2023)·9 citations
31. 31*

    Interactions of $\pi K$, $\pi \pi K$ and $KK\pi$ systems at maximal isospin from lattice QCD

    Zachary T. Draper🇺🇸 · Andrew D. Hanlon🇺🇸 · Ben Hörz🇩🇪 · Colin Morningstar🇺🇸 · Fernando Romero-López🇺🇸 · Stephen R. Sharpe🇺🇸

    We study the interactions of systems of two and three nondegenerate mesons composed of pions and kaons at maximal isospin using lattice QCD, specifically ${\pi }^{+}{K}^{+}$, ${\pi }^{+}{\pi }^{+}{K}^{+}$ and $K^{+}{K}^{+}{\pi }^{+}$. Utilizing the stochastic LapH method, we determine the spectrum of these systems on two CLS $N_f=2+1$ ensembles with pion masses of $200$ MeV and $340$ MeV, and include many levels in different momentum frames. We constrain the K matrices describing two- and three-particle interactions by fitting the spectrum to the results predicted by the finite-volume formalism, including up to $p$ waves. This requires also results for the ${\pi }^{+}{\pi }^{+}$ and $K^{+}{K}^{+}$ spectrum, which have been obtained previously on the same configurations. We explore different fitting strategies, comparing fits to energy shifts with fits to energies boosted to the rest frame, and also comparing simultaneous global fits to all relevant two- and three-particle channels to those where we first fit two-particle channels and then add in the three-particle information. We provide the first determination of the three-particle K matrix in ${\pi }^{+}{\pi }^{+}{K}^{+}$ and $K^{+}{K}^{+}{\pi }^{+}$ systems, finding statistically significant nonzero results in most cases. We include $s$ and $p$ waves in the K matrix for ${\pi }^{+}{K}^{+}$ scattering, finding evidence for an attractive $p$-wave scattering length. We compare our results to Chiral Perturbation Theory, including an investigation of the impact of discretization errors, for which we provide the leading order predictions obtained using Wilson Chiral Perturbation Theory.

    ↳ hep-lathep-phnucl-thJHEP(2023)·48 citations
32. 32*

    Evidence of Hexadecapole Deformation in Uranium-238 at the Relativistic Heavy Ion Collider

    Wouter Ryssens🇧🇪 · Giuliano Giacalone🇩🇪 · Björn Schenke🇺🇸 · Chun Shen🇺🇸

    There is strong evidence of the failure of hydrodynamic simulations of the quark-gluon plasma (QGP) to reproduce data on the elliptic flow of particles in relativistic collisions of ${}^{238}$U nuclei at the BNL Relativistic Heavy Ion Collider (RHIC). We demonstrate that this failure is caused by an inappropriate implementation of well-deformed ions, such as ${}^{238}$U, in the hydrodynamic framework. Past studies have identified the deformation of the nuclear surface with that of the nuclear volume, though these are different concepts. In particular, a volume quadrupole moment can be generated by both a surface hexadecapole and a surface quadrupole moment. This feature was so far neglected in the modeling of heavy-ion collisions, and is particularly relevant for nuclei like ${}^{238}$U, which is both quadrupole- and hexadecapole-deformed. With rigorous input from Skyrme density functional calculations, we show that correcting for such effects in the implementation of nuclear deformations in hydrodynamic simulations restores agreement with BNL RHIC data. This brings consistency to the results of nuclear experiments across energy scales, and demonstrates the impact of the hexadecapole deformation of ${}^{238}$U on high-energy collisions.

    ↳ nucl-thhep-exhep-phnucl-exPRL(2023)·90 citations
33. 33*

    Constraints on fundamental physical constants from bio-friendly viscosity and diffusion

    K. Trachenko🇬🇧

    The problem of understanding fundamental physical constants was discussed in particle physics, astronomy and cosmology. Here, I show that a new insight comes from condensed matter physics and liquid physics in particular: fundamental constants have a bio-friendly window constrained by bio-friendly viscosity and diffusion setting the motion in essential life processes in and across cells. I also show that bounds on viscosity, diffusion and the fundamental velocity gradient in a biochemical machine can all be varied while keeping the fine-structure constant and the proton-to-electron mass ratio intact, with no implication for the production of heavy nuclei in stars. This leads to a conjecture of multiple tuning and an evolutionary mechanism.

    ↳ cond-mat.softcond-mat.stat-mechhep-phhep-thSci.Adv.(2023)·3 citations
34. 34*

    Universe bouncing its way to inflation

    Manjeet Kaur🇮🇳 · Debottam Nandi🇮🇳 · Debajyoti Choudhury🇮🇳 · T. R. Seshadri🇮🇳

    Cosmological models with inflation and those with bounce have their own strengths and weaknesses. Here we construct a model in which a phase of bounce is followed by a viable inflationary phase. This incorporates several advantages of both and hence, is a more viable model for cosmic evolution. We explore scenarios wherein the bouncing phase smoothly transits to an inflationary one, with the pivot scale leaving the Hubble horizon during the latter era, thereby maintaining consistency with observations. Staying within the ambit of Einstein-Hilbert gravity augmented by the inflaton, we ensure a pre-inflationary bounce by introducing a second scalar field that helps engineer the requisite violation of the null energy condition. Potential ghost instabilities can be mitigated by invoking a non-trivial coupling between the two scalar fields.

    ↳ astro-ph.COgr-qchep-phInt.J.Mod.Phys.D(2024)·4 citations
35. 35*

    The radio shut-off, glitch, and X-ray burst in 1E 1547.0-5408 interpreted through magnetic reconfiguration

    Arthur G. Suvorov🇪🇸

    A short X-ray burst was observed from the radio-loud magnetar 1E 1547.0-5408 in 2022 April. Unusually however, the source stopped showing radio pulsations $\gtrsim 3$weeks prior to the burst. After recovery, radio timing revealed that the object had also undergone a modest glitch. A model for the overall event is constructed where an initially mild perturbation adjusts the magnetic geometry near the polar caps, leading to shallow fractures. Crustal ejecta or particles leaking from a pair-plasma fireball pollute the magnetospheric gaps, shutting off the pulsar mechanism, but the energy release is not yet large enough to noticeably enhance the X-ray flux. This perturbation gradually ramps, eventuating in a large-scale energy redistribution which fuels the burst. The star's mass quadrupole moment changes in tandem, issuing a glitch. Some quantitative estimates for the magnetic reconfiguration under this interpretation are provided, based on a quasi-static model where the fluid evolves through a sequence of hydromagnetic equilibria.

    ↳ astro-ph.HEhep-phMNRAS(2023)·6 citations
36. 36*

    Proton Charge Radius from Lepton Scattering

    Weizhi Xiong🇨🇳 · Chao Peng🇺🇸

    Protons are bound states of the strong interaction governed by Quantum Chromodynamics (QCD). Its charge radius ($r_E^p$) is an important quantity as it characterizes the spatial distribution of the proton's charge, which is carried by the quarks. On the other hand, the proton charge radius is an essential physical input for the bound-state Quantum Electrodynamic (QED) calculations for the hydrogen atomic energy levels. Nevertheless, the large discrepancy between $r_E^p$ measurements from muonic hydrogen spectroscopy, and those from $ep$ elastic scattering and ordinary hydrogen spectroscopy, have been puzzling physicists for over a decade. Tremendous efforts, in both theoretical and experimental sides, have been dedicated to providing various insights into this puzzle, yet certain issues still remain unresolved, particularly in the field of lepton scatterings. This review will focus on $r_E^p$ measurements using lepton scatterings, the recent theoretical and experimental developments in this field, as well as future experiments using this technique.

    ↳ nucl-exhep-exhep-phnucl-thUniverse(2023)·27 citations
37. 37*

    Rapidity scan with multistage hydrodynamic and statistical thermal models

    Lipei Du🇨🇦 · Han Gao🇨🇦 · Sangyong Jeon🇨🇦 · Charles Gale🇨🇦

    We calibrate a (3+1)-dimensional multistage hybrid framework using the measured pseudo-rapidity distribution of charged particles and rapidity distribution of net protons for central Au+Au collisions at $\sqrt{s_{\mathrm{NN}}}=7.7,19.6,62.4,200$ GeV. We then study the thermodynamic properties of the nuclear matter along the beam direction, and the phase diagram regions probed by the hadronization process near the chemical freeze-out. Using the rapidity-dependent thermal yields of identified particles with full rapidity coverage from the hybrid framework, we apply different scenarios of the statistical thermal model to extract the thermodynamic parameters at the freeze-out, with the known system properties from the hybrid model as a closure test. We find significant theoretical uncertainties in the thermal models when applied to regions away from midrapidity. We also propose a thermal model inspired by the hybrid approach that includes thermal smearing and longitudinal flow for the nuclear matter created at low beam energies.

    ↳ nucl-thhep-phnucl-exPRC(2024)·27 citations
38. 38*

    Bayesian parameter estimation on boson-star binary signals with a coherent inspiral template and spin-dependent quadrupolar corrections

    Massimo Vaglio🇮🇹 · Costantino Pacilio🇮🇹 · Andrea Maselli🇮🇹 · Paolo Pani🇮🇹

    Compact boson star binaries are hypothetical sources for ground-based and space gravitational-wave detectors. Their signal would be a messenger for novel fundamental fields and could shed light on the dark matter. In this work, we further develop our analysis in Phys. Rev. D 102, 083002 (2020), aimed at constraining the properties of these objects with future observations. We use a coherent waveform template for the inspiral stage of boson star binaries with large quartic self interactions, including tidal deformability and the nonlinear dependence of the quadrupole moments on the spin in terms of the fundamental couplings of the scalar field theory. Performing a Bayesian analysis, we investigate the ability of a third-generation gravitational-wave detector such as the Einstein Telescope to distinguish these exotic sources from black holes and infer constraints on the fundamental couplings of the model.

    ↳ gr-qcastro-ph.HEhep-phPRD(2023)·23 citations
39. 39*

    Electromagnetic modeling and science reach of DMRadio-m${}^3$

    DMRadio Collaboration: A. AlShirawi🇺🇸 · V. Ankel🇺🇸 · C. Bartram🇺🇸 · J. Begin🇺🇸 · C. Bell🇺🇸 · J. N. Benabou🇺🇸 · L. Brouwer🇺🇸 · S. Chaudhuri🇺🇸 · H. -M. Cho🇺🇸 · J. Corbin🇺🇸 · W. Craddock🇺🇸 · S. Cuadra🇺🇸 and 35 other authors

    DMRadio-m${}^3$ is an experiment that is designed to be sensitive to KSVZ and DFSZ QCD axion models in the 10--200\,MHz (41 neV$/c^2$ -- 0.83 $\mu$eV/$c^2$) range. The experiment uses a solenoidal dc magnetic field to convert an axion dark-matter signal to an ac electromagnetic response in a coaxial copper pickup. The current induced by this axion signal is measured by dc SQUIDs. In this work, we present the electromagnetic modeling of the response of the experiment to an axion signal over the full frequency range of DMRadio-m${}^3$, which extends from the low-frequency, lumped-element limit to a regime where the axion Compton wavelength is only a factor of two larger than the detector size. With these results, we determine the live time and sensitivity of the experiment. The primary science goal of sensitivity to DFSZ axions across 30--200 MHz can be achieved with a $3\sigma$ live scan time of 2.9 years.

    ↳ hep-exastro-ph.COhep-phphysics.ins-detPRD(2025)·32 citations
40. 40*

    On the equivalence of the Pais-Uhlenbeck oscillator model and two non-Hermitian Harmonic Oscillators

    Frieder Kleefeld (Collab. of CeFEMA, IST, Lisbon, Portugal)🇵🇹

    A system of two independent Bosonic Harmonic Oscillators is converted into the respective fourth-order derivative Pais-Uhlenbeck oscillator model. The conversion procedure displays transparently how the quantization of the fourth-order derivative Pais-Uhlenbeck oscillator has to be performed in order not to suffer from the divergence problems of the vacuum state and path integrals as conjectured most recently by P. D. Mannheim in his article ``Determining the normalization of the quantum field theory vacuum, with implications for quantum gravity" [arXiv:2301.13029 [hep-th]]. In order to make the case we present the construction of the path integral, generating functionals and vacuum persistence amplitudes for PT-symmetry completed systems in Quantum Mechanics and Quantum Field Theory and discuss some implications to Quantum Field Theory and Particle Physics.

    ↳ quant-phhep-phhep-th4 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.