Tue·Mar 21, 2023Tuesday·March 21, 2023

1. 01*

   Top quark effective couplings from top-pair tagged photoproduction in $\mathbf{p}{\mathbf{e}}^{-}$ collisions

   Antonio O. Bouzas🇲🇽 · F. Larios🇲🇽

   We summarize the quantitative results of our analysis [1] of top-pair photoproduction in semileptonic mode in $pe$ collisions at the LHeC and FCC-he. We define three photoproduction regions, based on the rapidity acceptance range of the electron tagger, that provide different degrees of sensitivity to top-quark effective couplings. We focus on the $t\bar{t}\gamma$ dipole couplings and the left-handed vector $tbW$ coupling, for which we determine limits at both energies in the different photoproduction regions. We find that the LHeC and FCC-he will yield tight direct bounds on top dipole moments, greatly improving on current direct limits from hadron colliders, and direct limits on the $tbW$ coupling as restrictive as those expected from the HL-LHC. We also consider indirect limits from $b\to s\gamma$ branching ratio and $CP$ asymmetry, that are well known to be very sensitive probes of top electromagnetic dipole moments.

   hep-phRev.Mex.Fis.Suppl.(2023)·0 citations
2. 02*

   Mass spectrum and decays of the first radial excitation axial vector meson nonet

   Xue-Chao Feng🇨🇳 · Ke-Wei Wei🇨🇳

   In this work, the mass spectrum of the first radial excitation axial vector meson nonet is considered in the framework of the nonrelativistic constituent quark model and Regge phenomenology. After that, we investigate the strong decay characteristics of these states within the ${}^3{P}_0$ model. The results are compared to values from other phenomenological models, and they may be beneficial in the prospective search for $2^3{P}_1$ meson nonets.

   hep-phInt.J.Mod.Phys.A(2023)·3 citations
3. 03*

   Indian Contributions to LHC Theory

   Sreerup Raychaudhuri🇮🇳

   Indian scientists began to work on the theoretical aspects of LHC physics from the early 1980s, at the same time when the rest of the world started taking interest in this then-futuristic topic. From this point grew a whole school of collider phenomenologists, who now form a significant fraction of the Indian high-energy physics community. This article briefly reviews the growth and contributions of the Indian school, on the way describing some of the physics ideas while placing the work in the international context, and proceeding thus, brings the story up to date in mid-2022.

   hep-phEur.Phys.J.ST(2023)·1 citation
4. 04*

   Impact of Dimension-8 SMEFT operators on Diboson Productions

   Céline Degrande🇧🇪 · Hao-Lin Li🇧🇪

   We for the first time identify all the dimension-8 (dim-8) SMEFT operators that can have an interference with the SM with $E^4/{\Lambda }^4$ enhancement in the high energy limit for the processes $q\bar{q}\to WW/WZ$. Our results therefore explicitly show that the non-interference observed for the dimension-six does not extend to dimension-eight. We compute the contributions of those dimension-8 operators to the cross-section at the 14 TeV Large Hadron Collider and compare the results with dimension-6 (dim-6) originated corrections at the order of dim-6-SM interference and dim-6 squared. We find one (two) dim-8 operator(s) can generate amplitudes of a similar order of magnitude compared with their dim-6 squared counterparts assuming unity dimensionless Wilson coefficients. During the study, new non-interference scenarios are found due to the selection rule of angular momentum as well as strong suppression due to the symmetric initial state for the proton-proton collider.

   hep-phJHEP(2023)·43 citations
5. 05*

   Shining massive light through a wall

   P. C. Malta

   A massive photon possesses a longitudinal polarization mode absent in its massless counterpart. Transverse and longitudinal modes follow different dispersion relations, the latter being much less attenuated than the former when passing through a conductor, suggesting the possibility of isolating longitudinal modes by shining intense light on a conducting wall. We calculate the transmission rates for normal incidence upon a semi-infinite medium and passage through a slab. For the second case we compare the expected photon fluxes with those measurable in current and future light-shining-through-a-wall experiments. Using a 1-MW microwave source as envisaged by the STAX project, a sensitivity at the level of $m_{\gamma }<9.6\times 10^{-11}eV/{\mathrm{c}}^2$ could be reached after a run time of an year, with a potential improvement by a factor of $\sim 10^4$ if radio waves of similar power are used.

   hep-phphysics.opticsPRD(2023)·2 citations
6. 06*

   A search for neutron-to-hidden-neutron oscillations in a ultra-cold neutron beam

   G. Ban🇫🇷 · J. Chen🇫🇷 · P.-J. Chiu🇨🇭 · B. Clément🇫🇷 · M. Guigue🇫🇷 · T. Jenke🇫🇷 · P. Larue🇫🇷 · T. Lefort🇫🇷 · O. Naviliat-Cuncic🇫🇷 · B. Perriolat🇫🇷 · G. Pignol🇫🇷 · S. Roccia🇫🇷 · W. Saenz-Arevalo🇫🇷 · P. Schmidt-Wellenburg🇨🇭

   Models that postulate the existence of hidden sectors address contemporary questions, such as the source of baryogenesis and the nature of dark matter. Among the possible mixing processes, neutron-to-hidden-neutron oscillations have been repeatedly tested with ultra-cold neutron storage and passing-through-wall experiments in the range of small ($\delta m<2$ peV) and large mass splitting ($\delta m>10$ neV), respectively. In this work, we present a new constraint in the oscillation parameter space derived from neutron disappearance in ultra-cold neutron beam experiments. The overall limit, which covers the intermediate mass-splitting range, is given by ${\tau }_{n{n}^{\prime }}>1$ s for $|\delta m|\in [2,69]$ peV (95\% C.L.).

   hep-phPRL(2023)·17 citations
7. 07*

   Impact of nuclear matrix element calculations for current and future neutrinoless double beta decay searches

   Federica Pompa🇪🇸 · Thomas Schwetz🇩🇪 · Jing-Yu Zhu🇩🇪

   Nuclear matrix elements (NME) are a crucial input for the interpretation of neutrinoless double beta decay data. We consider a representative set of recent NME calculations from different methods and investigate the impact on the present bound on the effective Majorana mass $m_{\beta \beta }$ by performing a combined analysis of the available data as well as on the sensitivity reach of future projects. A crucial role is played by the recently discovered short-range contribution to the NME, induced by light Majorana neutrino masses. Depending on the NME model and the relative sign of the long- and short-range contributions, the current $3\sigma$ bound can change between $m_{\beta \beta }<40$ meV and 600 meV. The sign-uncertainty may either boost the sensitivity of next-generation experiments beyond the region for $m_{\beta \beta }$ predicted for inverted mass ordering or prevent even advanced setups to reach this region. Furthermore, we study the possibility to distinguish between different NME calculations by assuming a positive signal and by combining measurements from different isotopes. Such a discrimination will be impossible if the relative sign of the long- and short-range contribution remains unknown, but can become feasible if $m_{\beta \beta }\gtrsim 40$ meV and if the relative sign is known to be positive. Sensitivities will be dominated by the advanced ${}^{76}$Ge and ${}^{136}$Xe setups assumed here, but NME model-discrimination improves if data from a third isotope is added, e.g., from ${}^{130}$Te or ${}^{100}$Mo.

   hep-phJHEP(2023)·9 citations
8. 08*

   Electromagnetic properties of ${\bar{D}}^{(\ast )}{\Xi }_c^{\prime }$, ${\bar{D}}^{(\ast )}{\Lambda }_c$, ${\bar{D}}_s^{(\ast )}{\Lambda }_c$ and ${\bar{D}}_s^{(\ast )}{\Xi }_c$ pentaquarks

   U. Özdem🇹🇷

   To elucidate the internal structure of exotic states is one of the central purposes of hadron physics. Motivated by this, we study the electromagnetic properties of ${\bar{D}}^{(\ast )}{\Xi }_c^{\prime }$, ${\bar{D}}^{(\ast )}{\Lambda }_c$, ${\bar{D}}_s^{(\ast )}{\Lambda }_c$ and ${\bar{D}}_s^{(\ast )}{\Xi }_c$ pentaquarks without strange, with strange and with double strange through QCD light-cone sum rules. We have also evaluated electric quadrupole and magnetic octupole moments of the ${\bar{D}}^{\ast }{\Xi }_c^{\prime }$, ${\bar{D}}^{\ast }{\Lambda }_c$, ${\bar{D}}_s^{\ast }{\Lambda }_c$ and ${\bar{D}}_s^{\ast }{\Xi }_c$ pentaquarks. The magnetic dipole moment is the leading-order response of a bound system to a soft external magnetic field. Thus, it ensures a prominent platform for the examination of the internal organizations of hadrons governed by the quark-gluon dynamics of QCD. We look forward to the present study stimulating the interest of experimentalists in investigating the electromagnetic properties of the hidden-charm pentaquarks.

   hep-phhep-exhep-latPLB(2023)·32 citations
9. 09*

   Investigate the strong coupling of $g_{XJ/\psi \varphi }$ in $X(4500)\to J/\psi \varphi$ by using the three-point sum rules and the light-cone sum rules

   Yiling Xie🇨🇳 · Hao Sun🇨🇳

   We assign $X(4500)$ as a D-wave tetraquark state and study the decay of $X(4500)$ $\to$ $J/\psi \varphi$. The mass and the decay constant of $X(4500)$ are calculated by using the SVZ sum rules. For the decay width of $X(4500)$ $\to$ $J/\psi \varphi$, we present the calculation within the framework of both the three-point sum rules and the light-cone sum rules. The strong coupling $g_{XJ/\psi \varphi }$ is obtained by considering the soft-meson approximation when we use the light-cone sum rules calculation. Both calculations show that the decay of $X(4500)$ $\to$ $J/\psi \varphi$ close to the total width of $X(4500)$ if we assign $X$(4500) as a D-wave tetraquark. In this paper, only the hidden-charm decay channel is considered. With these results and those from the open-charm decay channel, we are able to give a more rational conclusion when comparing with the total width of $X(4500)$. In the future, experiments will be more helpful in determining whether or not this structure of $X(4500)$ is appropriate.

   hep-phNPB(2024)·2 citations
10. 10*

    QCD Phase Diagrams via QHD and MIT-Based Models

    Carline Biesdorf🇧🇷 · Debora P. Menezes🇧🇷 · Luiz L. Lopes🇧🇷

    In this paper the QCD phase diagram is obtained by the crossing of two effective models: the MIT bag based models are used to describe quark matter and QHD type models to describe hadronic matter, being the use of the former something new to this kind of approach and the latter used with improved parameterizations as compared with previous calculations. We use the Gibbs' conditions to establish the crossing points of the pressure in function of the chemical potential obtained in both phases. We first analyze two-flavour symmetric matter constrained to both the freeze-out and the liquid-gas phase transition at the hadronic phase. Later we analyse the results for $\beta$-stable and charge neutral stellar matter and compare two different prescriptions: one that assumes flavour conservation, so that the quark phase is completely determined from the hadronic phase, a prescription never applied to finite temperatures before, and the other based on the Maxwell construction, where the quark phase is also $\beta$-stable. At the end, we compute the latent heat to find a signature of the critical end point.

    hep-phnucl-thBraz.J.Phys.(2023)·7 citations
11. 11*

    Transfer of spin to orbital angular momentum in the Bethe-Heitler process

    Shaohu Lei🇨🇳 · Shiyu Liu🇨🇳 · Weiqing Wang🇨🇳 · Zhigang Bu🇨🇳 · Baifei Shen🇨🇳 · Liangliang Ji🇨🇳

    According to the conservation of angular momentum, when a plane-wave polarized photon splits into a pair of electron-positron under the influence of the Coulomb field, the spin angular momentum (SAM) of the photon is converted into the angular momentum of the leptons. We investigate this process (the Bethe-Heitler process) by describing the final electron and positron with twisted states and find that the SAM of the incident photon is not only converted into SAM of the produced pair, but also into their orbital angular momentum (OAM), which has not been considered previously. The average OAM gained by the leptons surpasses the average SAM, while their orientations coincide. Both properties depend on the energy and open angle of the emitted leptons. The demonstrated spin-orbit transfer shown in the Bethe-Heitler process may exist in a large group of QED scattering processes.

    hep-phPRD(2023)·3 citations
12. 12*

    Interactions of electrical and magnetic charges and dark topological defects

    Akifumi Chitose🇯🇵 · Masahiro Ibe🇯🇵

    We consider a model of dark photon which appears as a result of the successive symmetry breaking SU(2)$\to$U(1)$\to {\mathbb{Z}}_2$, where various types of topological defects appear in the dark sector. In this paper, we study the interactions between QED charges and the dark topological defects through mixing between QED photon and dark photon. In particular, we extend our previous analysis by incorporating the magnetic mixing and $\theta$-terms. We also consider the dyons and dyonic beads in the dark sector. Notably, dark magnetic/dyonic beads are found to induce a QED Coulomb potential through the magnetic mixing despite finite mass of the dark photon.

    hep-phhep-thPRD(2023)·5 citations
13. 13*

    Reconstruction of baryon number distributions

    Chuang Huang🇨🇳 · Yang-yang Tan🇨🇳 · Rui Wen🇨🇳 · Shi Yin🇨🇳 · Wei-jie Fu🇨🇳

    The maximum entropy method (MEM) and the Gaussian process (GP) regression, which are both well-suited for the treatment of inverse problems, are used to reconstruct net-baryon number distributions based on a finite number of cumulants of the distribution. Baryon number distributions across the chiral phase transition are reconstructed. It is found that with the increase of the order of cumulants, distribution in the long tails, i.e., far away from the central number, would become more and more important. We also reconstruct the distribution function based on the experimentally measured cumulants at the collision energy $\sqrt{s_{NN}}=7.7$ GeV. Given the sizable error of the fourth-order cumulant measured in experiments, the calculation of MEM shows that with the increasing fourth-order cumulant, there is another peak in the distribution function developed in the region of large baryon number. This unnaturalness observed in the reconstructed distribution function might in turn be used to constrain the cumulants measured in experiments.

    hep-phnucl-thCPC(2023)·4 citations
14. 14*

    Comprehensive study of Lorentz invariance violation in atmospheric and long-baseline experiments

    Deepak Raikwal🇮🇳 · Sandhya Choubey🇸🇪 · Monojit Ghosh🇭🇷

    In this paper, we have presented a comprehensive study of Lorentz Invariance Violation (LIV) in the context of atmospheric neutrino experiment ICAL and long-baseline experiments T2HK and DUNE. Our study consists of the full parameter space of the LIV parameters (isotropic), i.e., six CPT violating LIV parameters ($a_{\alpha \beta }$) and six CPT conserving LIV parameters ($c_{\alpha \beta }$). In this study, our objective is to calculate the upper bound on all the LIV parameters with respect to the individual experiments and their combination. Our results show that DUNE gives the best sensitivity for the parameters $a_{ee}$, $a_{e\mu }$, $a_{e\tau }$ and $a_{\mu \tau }$ in its 7 years of running whereas ICAL gives the best sensitivity on $a_{\mu \mu }$, $a_{\mu \tau }$, $c_{ee}$, $c_{\mu \mu }$, $c_{\tau \tau }$ and $c_{\mu \tau }$ in its 10 years of running. For $a_{\tau \tau }$, the sensitivity of DUNE and ICAL is similar. The combination of T2HK, DUNE and ICAL, gives the best sensitivity for $a_{e\mu }$ and $a_{ee}$ with respect to all the existing bounds in the literature. For the CPT even diagonal parameters (isotropic) $c_{ee}$ and $c_{\mu \mu }$, our work provides the first ever bounds.

    hep-phhep-exPRD(2023)·13 citations
15. 15*

    Modular $A_4$ symmetry in 3+1 active-sterile neutrino masses and mixings

    Mayengbam Kishan Singh🇮🇳 · S. Robertson Singh🇮🇳 · N. Nimai Singh🇮🇳

    Motivated by the significance of modular symmetry in generating neutrino masses and flavor mixings, we apply the modular $A_4$ symmetry in a 3+1 scheme of active-sterile neutrino mixings. Neutrino oscillation observables in the 3$\sigma$ range are successfully reproduced through the vacuum expectation value of the modulus $\tau$. We also study phenomenologies related to the effective neutrino masses $m_{\beta }$ in tritium beta decay and $m_{\beta \beta }$ in neutrinoless double beta decay. Mixings between active neutrinos and eV scale sterile neutrino are analyzed in detail. The model also predicts the Dirac CP-violating phase ${\delta }_{CP}$ and Majonara phases $\alpha$ and $\beta$. The best-fit values of the neutrino mixing angles and ratios of two mass-squared differences are determined using minimum ${\chi }^2$ analysis. The best-fit values of the neutrino oscillation observables are predicted as ${\sin }^2{\theta }_{23}=0.573,$ ${\sin }^2{\theta }_{12}=0.300,$ ${\sin }^2{\theta }_{13}=0.022$ and $r=0.172$ for NH while ${\sin }^2{\theta }_{23}=0.550,$ ${\sin }^2{\theta }_{12}=0.303,$ ${\sin }^2{\theta }_{13}=0.022$ and $r=0.171$ for IH. We also observe that the predictions of effective neutrino mass parameters in the 3+1 scheme are significantly different from the three neutrino paradigm.

    hep-phInt.J.Mod.Phys.A(2024)·7 citations
16. 16*

    On massive neutral lepton scattering on nucleus

    V.A.Bednyakov🇷🇺

    The paper presents a theoretical approach to the description of the relativistic scattering of a massive (neutral) lepton on a nucleus, in which the latter retains its integrity. The measurable cross section of this process includes the elastic (or coherent) contribution, when the nucleus remains in its original quantum state and the inelastic (incoherent) contribution, when the nucleus goes into another (excited) quantum state. Transition from the elastic scattering regime to the inelastic scattering regime is regulated automatically by the dependence of the form factors on the momentum transferred to the nucleus. At small momentum transfers elastic scattering dominates. AS the transferred momentum increases, the contribution of the inelastic scattering increases, and the latter becomes dominant at sufficiently large transferred momenta. The scattering of massive (anti)neutrinos interacting with nucleons through the $V\mp A$ currents of the Standard Model is considered in detail. Because of the nonzero masses, an additional channel arises for elastic and inelastic scattering of these (anti)neutrinos on nuclei due to the possibility of changing the helicity of these (anti)neutrinos. The expressions obtained for the cross sections are applicable to any precision data analysis involving neutrinos and antineutrinos, especially when non-zero neutrino masses can be taken into account. These expressions can also be used in the analysis of experiments on direct detection of (neutral) massive weakly interacting relativistic dark matter particles since, unlike the generally accepted case, they simultaneously take into account both elastic and inelastic interactions of the particles. The presence of an "inelastic signal" with its characteristic signature may be the only registrable evidence of interaction of the dark matter particle with the nucleus.

    hep-phPhys.Part.Nucl.(2023)·2 citations
17. 17*

    Flow fluctuations and kinetic freeze-out of identified hadrons at energies available at the CERN Super Proton Synchrotron

    Sudhir Pandurang Rode🇷🇺 · Partha Pratim Bhaduri🇮🇳 · Amaresh Jaiswal🇮🇳

    We investigate the effect of flow fluctuations, incorporated in non boost-invariant blast-wave model, on kinetic freeze-out parameters of identified hadrons in low energy relativistic heavy-ion collisions. For the purpose of this study, we use the transverse momentum spectra of the identified hadrons produced in central Pb--Pb collisions, at SPS energies ranging from ${\mathrm{E}}_{\mathrm{Lab}}=20A-158A$ GeV, and analyze them within a modified non boost-invariant blast wave model. We perform simultaneous fits of the transverse momentum spectra for light hadrons (${\pi }^{-}$, $K^{\pm }$, $p$) and heavy strange hadrons ($\Lambda$, $\bar{\Lambda }$, $\varphi$, ${\Xi }^{\pm }$, ${\Omega }^{\pm }$) seperately. We also fit the transverse momentum spectra of charmonia ($J/\Psi$, ${\Psi }^{\prime }$) at ${\mathrm{E}}_{\mathrm{Lab}}=158A$ GeV. Our findings suggest that the inclusion of flow fluctuations enhances kinetic freeze-out temperature in case of light and heavy strange hadrons and reduces the corresponding transverse flow velocities. Moreover, we find that the kinetic freeze-out parameters of the charmonia at ${\mathrm{E}}_{\mathrm{Lab}}=158A$ GeV are least affected by inclusion of flow fluctuations. Based on this, we make predictions which can provide further insights on the role of flow fluctuations in relativistic heavy-ion collisions.

    hep-phPRC(2023)·3 citations
18. 18*

    Revisiting Puffy Dark Matter with Novel Insights: Partial Wave Analysis

    Wenyu Wang🇨🇳 · Wu-Long Xu🇨🇳 · Jin Min Yang🇨🇳 · Bin Zhu🇨🇳

    We present a comprehensive study on the self-interaction cross-section of puffy dark matter (DM) particles, which have a significant intrinsic size compared to their Compton wavelength. For such puffy DM self-interaction cross-section in the resonant and classical regimes, our study demonstrates the significance of the Yukawa potential and the necessity of partial wave analysis: (i) Due to the finite-size effect of puffy DM particles, the new Yukawa potential of puffy DM is found to enlarge the Born-effective regime for the self-interaction cross-section, compared with the point-like DM; (ii) Our partial wave analysis shows that depending on the value of the ratio between $R_{\chi }$ (radius of a puffy DM particle) and $1/m_{\varphi }$ (force range), the three regimes (Born-effective, resonant and classical) for puffy DM self-interaction cross-section can be very different from the point-like DM; (iii) We find that to solve the small-scale anomalies via self-interacting puffy DM, the Born-effective and the resonant regimes exist for dwarf galaxies, while for the cluster and Milky Way galaxy the non-Born regime is necessary.

    hep-phastro-ph.HEhep-thJHEP(2023)·6 citations
19. 19*

    $W$ Boson Mass and Grand Unification via the Type-$\mathrm{I}\mathrm{I}$ Seesaw-like Mechanism

    Yusuke Shimizu🇯🇵 · Shonosuke Takeshita🇯🇵

    We propose an SU(5) GUT model extended with two additional pairs of $10$ representation vector-like fermions. The CDF collaboration $W$ boson mass anomaly is explained by using the VEV of a real $\mathrm{SU}(2{)}_{\mathrm{L}}$ triplet scalar coming from the $24$ representation Higgs. The vector-like fermions are decomposed partly into vector-like quark doublets. Those vector-like quark doublets acquire mass from two sources; through the Yukawa interaction with the real $\mathrm{SU}(2{)}_{\mathrm{L}}$ triplet via a type-$\mathrm{I}\mathrm{I}$ seesaw-like mechanism. And, they acquire mass from the $24$ representation Higgs. We assume that the mass for the vector-like quark doublets is expressed in terms of the real triplets mass. By combining the constraints on the vector-like quark masses with those on the heavy Higgs boson masses, we can obtain the narrow allowed mass ranges for the vector-like quark doublet and the real triplet. Therefore, our model can be tested in searches for these particles in the near future. In addition, the two additional pairs of vector-like fermions allow the SM gauge couplings to unify successfully at $M_{\mathrm{GUT}}\approx 5.1\times 10^{15}$~GeV. Our model is also testable by the future Hyper-Kamiokande experiment via the proton decay lifetime ${\tau }_p(p\to {\pi }^0{e}^{+})<1.0\times 10^{35}$~years.

    hep-phNPB(2023)·12 citations
20. 20*

    Leptogenesis and Neutrinoless Double Beta Decay in the Scotogenic Hybrid Textures of Neutrino Mass Matrix

    Ankush🇮🇳 · Rishu Verma🇮🇳 · Sahil Kumar🇨🇳 · B. C. Chauhan🇮🇳

    In our recent work we identify the hybrid textures of neutrino mass matrix which simultaneously account for dark matter (DM) and neutrinoless double beta decay ($0\nu \beta \beta$). We also obtained the bounds on dark matter mass and effective Majorana mass $|M_{ee}|$. In this work we look for those hybrid textures which altogether accounts for DM, $0\nu \beta \beta$ and leptogenesis. We have found correlation of baryon asymmetry of universe $Y$ with dark matter mass $M_1$ and effective Majorana mass $|M_{ee}|$. We use experimental bounds on relic density of dark matter ($\Omega h^2$) and baryon asymmetry of universe to identify the hybrid textures. We found that out of five hybrid textures which simultaneously satisfies the physics observations of the DM and $0\nu \beta \beta$ only three hybrid textures altogether satisfy the DM, $0\nu \beta \beta$ and leptogenesis. It is interesting to note that these three hybrid textures gives lower bound to the effective Majorana mass $|M_{ee}|$ which can be probed in current and future experiments like SuperNEMO, KamLAND-Zen, NEXT, and nEXO (5 year) have sensitivity reaches of 0.05 eV, 0.045 eV, 0.03 eV, and 0.015 eV, respectively.

    hep-phJCAP(2023)·3 citations
21. 21*

    Geometric Poisson distribution of photons produced in the ultrarelativistic hadronic collisions

    Rahul R Nair🇵🇱 · Grzegorz Wilk🇵🇱 · Zbigniew Włodarczyk🇵🇱

    We show that the multiplicity distribution of photons produced with enhanced void probability in inelastic proton-proton collisions at $\sqrt{s}=$ 900 GeV, 2.76 TeV, and 7 TeV, measured at forward rapidities by the ALICE experiment at LHC, can be described by the geometric Poisson distribution. The traditionally used negative binomial distribution fails to reproduce the enhanced void probability and the shape of the modified combinants simultaneously. Our findings are relevant for the theoretical modeling of photon production processes in high-energy hadronic collisions.

    hep-phEPJA(2023)·2 citations
22. 22*

    Electroweak baryogenesis via top-charm mixing

    Shinya Kanemura🇯🇵 · Yushi Mura🇯🇵

    We investigate a scenario of electroweak baryogenesis in the two Higgs doublet model with quark flavor mixing. In general, off-diagonal components of quark Yukawa interactions with additional Higgs bosons are strongly constrained by the data for flavor changing neutral currents. However, top-charm quark mixing is not the case, so that a large off-diagonal element can be taken, which can contribute to generating baryon asymmetry of the universe. It turns out that CP violating phases of the off-diagonal element in the source term in the Boltzmann equation are eliminated by the rephasing. This result is somewhat different from previous works on electroweak baryogenesis by flavor off-diagonal Yukawa couplings. Instead, we find that the absolute value of the top-charm off-diagonal element enhances CP violating phases in the Higgs potential, by which sufficient amount of the baryon number can be generated to explain the observed baryon asymmetry of the universe. We find that such a scenario is viable under the current experimental data. The model can be tested by the current and future measurements of various flavor experiments like Kaon rare decays, in addition to high energy collider experiments as well as gravitational wave observations. Characteristic predictions of our model would be deviations in Kaon rare decays. Branching ratios of $K^{+}\to {\pi }^{+}\nu \overline{\nu }$ and $K_L\to {\pi }^0\nu \overline{\nu }$ can deviate by the order of 10% and 1%, respectively, which may be tested at future Kaon experiments such as NA62 and KOTO step-2.

    hep-phJHEP(2023)·25 citations
23. 23*

    Bayesian inference for form-factor fits regulated by unitarity and analyticity

    J.M. Flynn🇬🇧 · A. Jüttner🇬🇧 · J.T. Tsang🇨🇭

    We propose a model-independent framework for fitting hadronic form-factor data, which is often only available at discrete kinematical points, using parameterisations based on to unitarity and analyticity. In this novel approach the latter two properties of quantum-field theory regulate the ill-posed fitting problem and allow model-independent predictions over the entire physical range. Kinematical constraints, for example for the vector and scalar form factors in semileptonic meson decays, can be imposed exactly. The core formulae are straight-forward to implement with standard math libraries. We take account of a generalisation of the original Boyd Grinstein Lebed (BGL) unitarity constraint for form factors and demonstrate our method for the exclusive semileptonic decay $B_s\to K\ell \nu$, for which we make a number of phenomenologically relevant predictions, including the CKM matrix element $|V_{ub}|$.

    hep-phhep-latJHEP(2023)·32 citations
24. 24*

    Absorption of Vector Dark Matter Beyond Kinetic Mixing

    Gordan Krnjaic🇺🇸 · Tanner Trickle🇺🇸

    Massive vector particles are minimal dark matter candidates that motivate a wide range of laboratory searches, primarily exploiting a postulated kinetic mixing with the photon. However, depending on the high energy field content, the dominant vector dark matter (VDM) coupling to visible particles may arise at higher operator dimension, motivating efforts to predict direct detection rates for more general interactions. Here we present the first calculation of VDM absorption through its coupling to electron electric (EDM) or magnetic (MDM) dipole moments, which can be realized in minimal extensions to the Standard Model and yield the observed abundance through a variety of mechanisms across the eV\,-\,MeV mass range. We compute the absorption rate of the MDM and EDM models for a general target, and then derive direct detection constraints from targets currently in use: Si and Ge crystals and Xe and Ar atoms. We find that current experiments are already sensitive to VDM parameter space corresponding to a cosmological freeze-in scenario, and future experiments will be able to completely exclude MDM and EDM freeze-in models with reheat temperatures below the electroweak scale. Additionally, we find that while constraints on the MDM interaction can be related to constraints on axion-like particles, the same is not true for the EDM model, so the latter absorption rate must be computed from first principles. To achieve this, we update the publicly available program EXCEED-DM to perform these new calculations.

    hep-phastro-ph.COPRD(2023)·12 citations
25. 25*

    Asymmetric di-Higgs signals of the next-to-minimal 2HDM with a $U(1)$ symmetry

    Sumit Banik🇨🇭 · Andreas Crivellin🇨🇭 · Syuhei Iguro🇩🇪 · Teppei Kitahara🇯🇵

    The two-Higgs-doublet model with a $U(1{)}_H$ gauge symmetry (N2HDM-$U(1)$) has several advantages compared to the ``standard'' $Z_2$ version (N2HDM-$Z_2$): It is purely based on gauge symmetries, involves only spontaneous symmetry breaking, and is more predictive because it contains one parameter less in the Higgs potential, which further ensures $CP$ conservation, i.e., avoiding the stringent bounds from electric dipole moments. After pointing out that a second, so far unknown version of the N2HDM-$U(1)$ exists, we examine the phenomenological consequences for the Large Hadron Collider (LHC) of the differences in the scalar potentials. In particular, we find that while the N2HDM-$Z_2$ predicts suppressed branching ratios for decays into different Higgs bosons for the case of the small scalar mixing (as suggested by Higgs coupling measurements), both versions of the N2HDM-$U(1)$ allow for sizable rates. This is particularly relevant in light of the CMS excess in resonant Higgs-pair production at around $650$GeV of a Standard Model Higgs boson subsequently decaying to photons and a new scalar with a mass of $\approx 90$GeV subsequently decaying to bottom quarks (i.e., compatible with the CMS and ATLAS $\gamma \gamma$ excesses at $95$GeV and $\approx 670$GeV). As we will show, this excess can be addressed within the N2HDM-$U(1)$ in case of a nonminimal Yukawa sector, predicting an interesting and unavoidable $Z+b\bar{b}$ signal and motivating further asymmetric di-Higgs searches at the LHC.

    hep-phhep-exPRD(2023)·41 citations
26. 26*

    Hunting for Neutral Leptons with Ultra-High-Energy Cosmic Rays

    Robert Heighton🇬🇧 · Lucien Heurtier🇬🇧 · Michael Spannowsky🇬🇧

    Next-generation large-volume detectors, such as GRAND, POEMMA, Trinity, TAROGE-M, TAMBO, or PUEO, have been designed to search for ultra-high-energy cosmic rays (UHECRs) with unprecedented sensitivity. We propose to use these detectors to search for new physics beyond the Standard Model (BSM). By considering the simple case of a right-handed neutrino that mixes exclusively with the active $\tau$ neutrino, we demonstrate that the existence of new physics can increase the probability for UHECRs to propagate through the Earth and produce extensive air showers that will be measurable soon. We compare the fluxes of such showers that would arise from various diffuse and transient sources of high-energy neutrinos, both in the Standard Model and in the presence of a right-handed neutrino. We show that detecting events with emergence angles $\gtrsim 10$ deg is promising to probe the existence of BSM physics, and we study the sensitivity of GRAND and POEMMA to do so. In particular, we show that the hypothesis of a right-handed neutrino with a mass of $\mathcal{O}(1-16)$ GeV may be probed in the future for mixing angles as small as $|U_{\tau N}{|}^2\gtrsim 10^{-7}$, thus competing with existing and projected experimental limits.

    hep-phastro-ph.HEPRD(2023)·5 citations
27. 27*

    Limits on Dark Matter Annihilation from the Shape of Radio Emission in M31

    Mitchell J. Weikert🇺🇸 · Matthew R. Buckley🇺🇸

    Well-motivated models of dark matter often result in a population of electrons and positrons within galaxies produced through dark matter annihilation -- usually in association with gamma rays. As they diffuse through galactic magnetic fields, these $e^{\pm }$ produce synchrotron radio emission. The intensity and morphology of this signal depends on the properties of the interstellar medium through which the $e^{\pm }$ propagate. Using observations of the Andromeda Galaxy (M31) to construct a model of the gas, magnetic fields, and starlight, we set constraints on dark matter annihilation to $b\bar{b}$ using the morphology of 3.6 cm radio emission. As the emission signal at the center of M31 is very sensitive to the diffusion coefficient and dark matter profile, we base our limits on the differential flux in the region between $0.9-6.9$ kpc from the center. We exclude annihilation cross sections $\gtrsim 3\times 10^{-25}$ cm${}^3$/s in the mass range $10-500$ GeV, with a maximum sensitivity of $7\times 10^{-26}$ cm${}^3$/s at $20-40$ GeV. Though these limits are weaker than those found in previous studies of M31, they are robust to variations of the diffusion coefficient.

    hep-phastro-ph.GAJHEP(2024)·3 citations
28. 28*

    The Universal One-Loop Effective Action with Gravity

    Rémy Larue🇫🇷 · Jérémie Quevillon🇫🇷

    We complete the so-called Universal One-Loop Effective Action (UOLEA) with effects of gravity and provide a systematic approach to incorporate higher dimensional operators in curved spacetime. The functional determinant stemming from the path integral is computed using the Covariant Derivative Expansion (CDE), in a momentum representation that does not rely on a specific choice of coordinate to be defined, as it often is. This very simple and efficient approach also manifests an interesting novelty as it allows to integrate out chiral fermions in curved spacetime in a direct manner. The presented method would very well fit in a code that performs CDE, offering the possibility to integrate out at one-loop fields on a curved spacetime background, including spin-2 fields, like the graviton. Eventually these results should provide an interesting way to study low energy effects of UV completions of gravity.

    ↳ hep-thgr-qchep-phJHEP(2023)·20 citations
29. 29*

    Three relativistic neutrons in a finite volume

    Zachary T. Draper🇺🇸 · Maxwell T. Hansen🇬🇧 · Fernando Romero-López🇺🇸 · Stephen R. Sharpe🇺🇸

    We generalize the relativistic field-theoretic (RFT) three-particle finite-volume formalism to systems of three identical, massive, spin-$1/2$ fermions, such as three neutrons. This allows, in principle, for the determination of the three-neutron interaction from the finite-volume spectrum of three-neutron states, which can be obtained from lattice QCD calculations.

    ↳ hep-lathep-phnucl-thJHEP(2023)·44 citations
30. 30*

    Uplift and towers of states in warped throat

    Min-Seok Seo🇰🇷

    We investigate the connection between the distance conjecture and the uplift potential. For this purpose, we consider the concrete model, the warped deformed conifold embedded into Type IIB flux compactifications, with the uplift potential produced by $\overline{D3}$-branes at the tip of the throat. Whereas the various mass scales associated with towers of states can be found, it turns out that the lightest tower mass scale satisfies the scaling behavior with respect to the uplift potential, which is meaningful provided the number of $\overline{D3}$-branes is nonzero. This indicates that the effective theory becomes invalid in the vanishing limit of the uplift potential by the descent of an infinite tower of states from UV, as predicted in the distance conjecture. Since too large uplift potential is also problematic due to the runaway behavior of the moduli potential as well as the sizeable backreaction of $\overline{D3}$-branes, the uplift potential is bounded from both above and below. In the simple model like the KKLT or the large volume scenario in which non-perturbative effect is dominatd by the single term, this bound can be rewritten as the bound on the size of the superpotential.

    ↳ hep-thhep-phJHEP(2023)·8 citations
31. 31*

    Exploring TeV candidates of Fermi blazars through machine learning

    J. T. Zhu🇨🇳 · C. Lin🇺🇸 · H. B. Xiao · J. H. Fan🇨🇳 · D. Bastieri🇨🇳 · G. G. Wang🇺🇸

    In this work, we make use of a supervised machine learning algorithm based on Logistic Regression (LR) to select TeV blazar candidates from the 4FGL-DR2 / 4LAC-DR2, 3FHL, 3HSP, and 2BIGB catalogs. LR constructs a hyperplane based on a selection of optimal parameters, named features, and hyper-parameters whose values control the learning process and determine the values of features that a learning algorithm ends up learning, to discriminate TeV blazars from non-TeV blazars. In addition, it gives the probability (or logistic) that a source may be considered as a TeV blazar candidate. Non-TeV blazars with logistics greater than 80% are considered high-confidence TeV candidates. Using this technique, we identify 40 high-confidence TeV candidates from the 4FGL-DR2 / 4LAC-DR2 blazars and we build the feature hyper-plane to distinguish TeV and non-TeV blazars. We also calculate the hyper-planes for the 3FHL, 3HSP, and 2BIGB. Finally, we construct the broadband spectral energy distributions (SED) for the 40 candidates, testing for their detectability with various instruments. We find that 7 of them are likely to be detected by existing or upcoming IACT observatories, while 1 could be observed with EAS particle detector arrays.

    ↳ astro-ph.HEhep-phApJ(2023)·7 citations
32. 32*

    Astrophysical and Cosmological Searches for Lorentz Invariance Violation

    Shantanu Desai🇮🇳

    Lorentz invariance is one of the fundamental tenets of Special Relativity, and has been extensively tested with laboratory and astrophysical observations. However, many quantum gravity models and theories beyond the Standard Model of Particle Physics predict a violation of Lorentz invariance at energies close to the Planck scale. This article reviews observational and experimental tests of Lorentz invariance violation (LIV) with photons, neutrinos and gravitational waves. Most astrophysical tests of LIV using photons are based on searching for a correlation of the spectral lag data with redshift and energy. These have been primarily carried out using compact objects such as pulsars, Active Galactic Nuclei (AGN), and Gamma-ray bursts (GRB). There have also been some claims for LIV from some of these spectral lag observations with GRBs, which however are in conflict with the most stringent limits obtained from other LIV searches. Searches have also been carried out using polarization measurements from GRBs and AGNs. For neutrinos, tests have been made using both astrophysical observations at MeV energies (from SN 1987A) as well as in the TeV-PeV energy range based on IceCube observations, atmospheric neutrinos, and long-baseline neutrino oscillation experiments. Cosmological tests of LIV entail looking for a constancy of the speed of light as a function of redshift using multiple observational probes, as well as looking for birefringence in Cosmic Microwave Background observations. This article will review all of these aforementioned observational tests of LIV, including results which are in conflict with each other.

    ↳ astro-ph.COastro-ph.HEgr-qchep-ph17 citations
33. 33*

    Quark mass dependence of $\pi \pi$ scattering in isospin 0, 1, and 2 from lattice QCD

    Arkaitz Rodas🇺🇸 · Jozef J. Dudek🇺🇸 · Robert G. Edwards🇺🇸

    Using lattice QCD we extract $\pi \pi$ scattering amplitudes with isospin--0,1,2 in low partial-waves at two values of the light quark mass corresponding to $m_{\pi }\sim 283$ and $330$ MeV. We confirm expectations of weak repulsion in isospin--2, and the presence of a narrow $\rho$ resonance in isospin--1, and study the pion mass dependence of these channels. In isospin--0 we find that the two pion masses considered straddle the point at which the $\sigma$ transitions from being a stable bound-state to being either a virtual bound-state or a subthreshold resonance. We discuss the ability of lattice calculations like these to precisely determine the $\sigma$ pole location when it is a resonance, and propose an approach in which the full complement of amplitudes computed in this paper can be used simultaneously to provide more constraint.

    ↳ hep-lathep-phPRD(2023)·49 citations
34. 34*

    Parity-Odd 3-Point Functions from CFT in Momentum Space and the Chiral Anomaly

    Claudio Corianò🇮🇹 · Stefano Lionetti🇮🇹 · Matteo Maria Maglio🇩🇪

    We illustrate how the Conformal Ward Identities (CWI) in momentum space for parity-odd correlators determine the structure of a chiral anomaly interaction, taking the example of the VVA (vector/vector/axial-vector) and AAA correlators in momentum space. Only the conservation and the anomalous WIs, together with the Bose symmetry, are imposed from the outset for the determination of the correlators. We use a longitudinal/transverse decomposition of tensor structures and form factors. The longitudinal (L) component is fixed by the anomaly content and the anomaly pole, while in the transverse (T) sector we define a new parameterization. We relate the latter both to the Rosenberg original representation of the VVA and to the longitudinal/transverse (L/T) one, first introduced in the analysis of $g-2$ of the muon in the investigation of the diagram in the chiral limit of QCD. The correlators are completely identified by the conformal constraints whose solutions are fixed only by the anomaly coefficient, the residue of the anomaly pole. In both cases, our CFT result matches the one-loop perturbative expression, as expected. The CWIs for correlators of mixed chirality $J_{L}J{J}_R$ generate solutions in agreement with the all-orders nonrenormalization theorems of perturbative QCD and in the chiral limit.

    ↳ hep-thhep-phEPJC(2023)·20 citations
35. 35*

    Primordial Gravitational Waves in non-Minimally Coupled Chromo-Natural Inflation

    Ema Dimastrogiovanni🇳🇱 · Matteo Fasiello🇪🇸 · Martino Michelotti🇳🇱 · Lucas Pinol🇪🇸

    We consider inflation driven by an axion-like particle coupled to an SU(2) gauge sector via a Chern-Simons term. Known as chromo-natural inflation, this scenario is in tension with CMB observations. In order to remedy this fact and preserve both the symmetries and the intriguing gravitational wave phenomenology exhibited by the model, we explore the non-minimal coupling of the axion-inflaton to the Einstein tensor. We identify regions of parameter space corresponding to a viable cosmology at CMB scales. We also highlight the possibility of a large and chiral gravitational wave signal at small scales. This is of particular interest for gravitational wave interferometers.

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2024)·32 citations
36. 36*

    Gradient-flowed order parameter for spontaneous gauge symmetry breaking

    Kengo Kikuchi🇯🇵 · Kenji Nishiwaki🇮🇳 · Kin-ya Oda🇯🇵

    The gauge-invariant two-point function of the Higgs field at the same spacetime point can make a natural gauge-invariant order parameter for spontaneous gauge symmetry breaking. However, this composite operator is ultraviolet divergent and is not well defined. We propose using a gradient flow to cure the divergence from putting the fields at the same spacetime point. As a first step, we compute it for the Abelian Higgs model with a positive mass squared at the one-loop order in the continuum theory using the saddle-point method to estimate the finite part. The order parameter consistently goes to zero in the infrared limit of the infinite flow time.

    ↳ hep-thhep-lathep-phEPJC(2023)·0 citations
37. 37*

    Statistical anisotropy in galaxy ellipticity correlations

    Maresuke Shiraishi🇯🇵 · Teppei Okumura🇹🇼 · Kazuyuki Akitsu🇺🇸

    As well as the galaxy number density and peculiar velocity, the galaxy intrinsic alignment can be used to test the cosmic isotropy. We study distinctive impacts of the isotropy breaking on the configuration-space two-point correlation functions (2PCFs) composed of the spin-2 galaxy ellipticity field. For this purpose, we build a formalism for general types of the isotropy-violating 2PCFs and a methodology to efficiently compute them by generalizing the polypolar spherical harmonic decomposition approach to the spin-weighted version. As a demonstration, we analyze the 2PCFs when the matter power spectrum has a well-known $g_{\ast }$-type isotropy-breaking term (induced by, e.g., dark vector fields). We then confirm that some anisotropic distortions indeed appear in the 2PCFs and their shapes rely on a preferred direction causing the isotropy violation, $\hat{d}$. Such a feature can be a distinctive indicator for testing the cosmic isotropy. Comparing the isotropy-violating 2PCFs computed with and without the plane parallel (PP) approximation, we find that, depending on $\hat{d}$, the PP approximation is no longer valid when an opening angle between the directions towards target galaxies is $\mathcal{O}(1^{\circ })$ for the density-ellipticity and velocity-ellipticity cross correlations and around $10^{\circ }$ for the ellipticity auto correlation. This suggests that an accurate test for the cosmic isotropy requires the formulation of the 2PCF without relying on the PP approximation.

    ↳ astro-ph.COgr-qchep-phJCAP(2023)·20 citations
38. 38*

    Taming Dyson-Schwinger equations with null states

    Wenliang Li🇨🇳

    In quantum field theory, the Dyson-Schwinger equations are an infinite set of coupled equations relating $n$-point Green's functions in a self-consistent manner. They have found important applications in non-perturbative studies, ranging from quantum chromodynamics and hadron physics to strongly correlated electron systems. However, they are notoriously formidable to solve. One of the main problems is that a finite truncation of the infinite system is underdetermined. Recently, Bender et al. [Phys. Rev. Lett. 130, 101602 (2023)] proposed to make use of the large-$n$ asymptotic behaviors and successfully obtained accurate results in $D=0$ spacetime. At higher $D$, it seems more difficult to deduce the large-$n$ behaviors. In this paper, we propose another avenue in light of the null bootstrap. The underdetermined system is solved by imposing the null state condition. This approach can be extended to $D>0$ more readily. As concrete examples, we show that the cases of $D=0$ and $D=1$ indeed converge to the exact results for several Hermitian and non-Hermitian theories of the $g{\varphi }^n$ type, including the complex solutions.

    ↳ hep-thhep-phmath-phmath.MP+2PRL(2023)·16 citations
39. 39*

    Quantum (in)stability of maximally symmetric space-times

    Jewel K. Ghosh🇧🇩 · Elias Kiritsis🇫🇷 · Francesco Nitti🇫🇷 · Valentin Nourry🇫🇷

    Classical gravity coupled to a CFT${}_4$ (matter) is considered. The effect of the quantum dynamics of matter on gravity is studied around maximally symmetric spaces (flat, de Sitter and Anti de Sitter). The structure of the graviton propagator is modified and non-trivial poles appear due to matter quantum effects. The position and residues of such poles are mapped as a function of the relevant parameters, the central charge of the CFT${}_4$, the two $R^2$ couplings of gravity as well as the curvature of the background space-time. The instabilities induced are determined. Such instabilities can be important in cosmology as they trigger the departure from de Sitter space and in some regions of parameters are more important than the well-known scalar instabilities. It is also determined when the presence of such instabilities is unreliable if the associated scales are larger than the ``species" cutoff of the gravitational theory.

    ↳ gr-qchep-phhep-thJHEP(2023)·11 citations
40. 40*

    Exclusive semileptonic $B_s\to K\ell \nu$ decays on the lattice

    Jonathan M. Flynn🇬🇧 · Ryan C. Hill🇬🇧 · Andreas Jüttner🇬🇧 · Amarjit Soni🇺🇸 · J. Tobias Tsang🇨🇭 · Oliver Witzel🇩🇪

    Semileptonic $B_s\to K\ell \nu$ decays provide an alternative $b$-decay channel to determine the CKM matrix element $|V_{ub}|$, and to obtain a $R$-ratio to investigate lepton-flavor-universality violations. Results for the CKM matrix element may also shed light on the discrepancies seen between analyses of inclusive or exclusive decays. We calculate the decay form factors using lattice QCD with domain-wall light quarks and a relativistic $b$-quark. We analyze data at three lattice spacings with unitary pion masses down to $268\mathrm{MeV}$. Our numerical results are interpolated/extrapolated to physical quark masses and to the continuum to obtain the vector and scalar form factors $f_{+}(q^2)$ and $f_0(q^2)$ with full error budgets at $q^2$ values spanning the range accessible in our simulations. We provide a possible explanation of tensions found between results for the form factor from different lattice collaborations. Model- and truncation-independent $z$-parameterization fits following a recently proposed Bayesian-inference approach extend our results to the entire allowed kinematic range. Our results can be combined with experimental measurements of $B_s\to D_s$ and $B_s\to K$ semileptonic decays to determine $|V_{ub}|=3.8(6)\times 10^{-3}$. The error is currently dominated by experiment. We compute differential branching fractions and two types of $R$ ratios, the one commonly used as well as a variant better suited to test lepton-flavor universality.

    ↳ hep-lathep-phPRD(2023)·51 citations
41. 41*

    Rethinking SO(3)-equivariance with Bilinear Tensor Networks

    Chase Shimmin🇺🇸 · Zhelun Li🇨🇦 · Ema Smith🇺🇸

    Many datasets in scientific and engineering applications are comprised of objects which have specific geometric structure. A common example is data which inhabits a representation of the group SO$(3)$ of 3D rotations: scalars, vectors, tensors, \textit{etc}. One way for a neural network to exploit prior knowledge of this structure is to enforce SO$(3)$-equivariance throughout its layers, and several such architectures have been proposed. While general methods for handling arbitrary SO$(3)$ representations exist, they computationally intensive and complicated to implement. We show that by judicious symmetry breaking, we can efficiently increase the expressiveness of a network operating only on vector and order-2 tensor representations of SO$(2)$. We demonstrate the method on an important problem from High Energy Physics known as \textit{b-tagging}, where particle jets originating from b-meson decays must be discriminated from an overwhelming QCD background. In this task, we find that augmenting a standard architecture with our method results in a \ensuremath{2.3\times} improvement in rejection score.

    ↳ cs.LGhep-exhep-ph2 citations
42. 42*

    Dixon-Rosenfeld Lines and the Standard Model

    David Chester🇺🇸 · Alessio Marrani🇪🇸 · Daniele Corradetti🇵🇹 · Raymond Aschheim🇺🇸 · Klee Irwin🇺🇸

    We present three new coset manifolds named Dixon-Rosenfeld lines that are similar to Rosenfeld projective lines except over the Dixon algebra $\mathbb{C}\otimes \mathbb{H}\otimes \mathbb{O}$. Three different Lie groups are found as isometry groups of these coset manifolds using Tits' formula. We demonstrate how Standard Model interactions with the Dixon algebra in recent work from Furey and Hughes can be uplifted to tensor products of division algebras and Jordan algebras for a single generation of fermions. The Freudenthal-Tits construction clarifies how the three Dixon-Rosenfeld projective lines are contained within $\mathbb{C}\otimes \mathbb{H}\otimes J_2(\mathbb{O})$, $\mathbb{O}\otimes J_2(\mathbb{C}\otimes \mathbb{H})$, and $\mathbb{C}\otimes \mathbb{O}\otimes J_2(\mathbb{H})$.

    ↳ hep-thhep-phmath-phmath.MPEPJC(2023)·6 citations
43. 43*

    Determining probability density functions with adiabatic quantum computing

    Matteo Robbiati🇮🇹 · Juan M. Cruz-Martinez🇨🇭 · Stefano Carrazza🇮🇹

    The two main approaches to quantum computing are gate-based computation and analog computation, which are polynomially equivalent in terms of complexity, and they are often seen as alternatives to each other. In this work, we present a method for fitting one-dimensional probability distributions as a practical example of how analog and gate-based computation can be used together to perform different tasks within a single algorithm. In particular, we propose a strategy for encoding data within an adiabatic evolution model, which accomodates the fitting of strictly monotonic functions, as it is the cumulative distribution function of a dataset. Subsequently, we use a Trotter-bounded procedure to translate the adiabatic evolution into a quantum circuit in which the evolution time t is identified with the parameters of the circuit. This facilitates computing the probability density as derivative of the cumulative function using parameter shift rules.

    ↳ quant-phhep-phQuantum Machine Intelligence(2025)·12 citations
44. 44*

    Bimetric-Affine Quadratic Gravity

    Ioannis D. Gialamas🇪🇪 · Kyriakos Tamvakis🇬🇷

    Bimetric gravity, is a theory of gravity that posits the existence of two interacting and dynamical metric tensors. The spectrum of bimetric gravity consists of a massless and a massive spin-2 particle. The form of the interactions between the two metrics $g_{\mu \nu }$ and $f_{\mu \nu }$ is constrained by requiring absence of the so called Boulware-Deser ghost. In this work we extend the original bimetric theory to its bimetric-affine counterpart, in which the two connections, associated with the Ricci scalars, are treated as independent variables. We examine in detail the case of an additional quadratic in the Ricci scalar curvature term ${\mathcal{R}}^2(g,\Gamma )$ and we find that this theory is free of ghosts for a wide range of the interaction parameters, not excluding the possibility of a Dark Matter interpretation of the massive spin-2 particle.

    ↳ gr-qcastro-ph.COhep-phhep-thPRD(2023)·25 citations
45. 45*

    Strongly interacting matter exhibits deconfined behavior in massive neutron stars

    Eemeli Annala🇫🇮 · Tyler Gorda🇩🇪 · Joonas Hirvonen🇫🇮 · Oleg Komoltsev🇳🇴 · Aleksi Kurkela🇳🇴 · Joonas Nättilä🇺🇸 · Aleksi Vuorinen🇫🇮

    Neutron-star cores contain matter at the highest densities in our Universe. This highly compressed matter may undergo a phase transition where nuclear matter melts into deconfined quark matter, liberating its constituent quarks and gluons. Quark matter exhibits an approximate conformal symmetry, predicting a specific form for its equation of state (EoS), but it is currently unknown whether the transition takes place inside at least some physical neutron stars. Here, we quantify this likelihood by combining information from astrophysical observations and theoretical calculations. Using Bayesian inference, we demonstrate that in the cores of maximally massive stars, the EoS is consistent with quark matter. We do this by establishing approximate conformal symmetry restoration with high credence at the highest densities probed and demonstrating that the number of active degrees of freedom is consistent with deconfined matter. The remaining likelihood is observed to correspond to EoSs exhibiting phase-transition-like behavior, treated as arbitrarily rapid crossovers in our framework.

    ↳ astro-ph.HEhep-phnucl-thNature Commun.(2023)·210 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.