Tue·May 9, 2023Tuesday·May 9, 2023

1. 01*

   New Horizons in the Holographic Conformal Phase Transition

   Cem Eröncel🇹🇷 · Jay Hubisz🇺🇸 · Seung. J. Lee🇰🇷 · Gabriele Rigo🇫🇷 · Bharath Sambasivam🇺🇸

   We describe cosmological solutions of the holographic dilaton with the aim of exploring alternatives to the commonly studied thermal Randall-Sundrum phase transition. It is well known that the thermal transition is typically strongly first order, with the requirement of a perturbative 5D gravity theory obstructing completion of the transition. This thermal transition corresponds to nucleation of an infrared brane through the surface of an AdS-Schwarzschild horizon. The approach we study instead invokes an early epoch in which the cosmology is fully 5-dimensional, with highly relativistic brane motion, and with Rindler horizons obscuring the infrared brane at early times. Our approach corresponds, via AdS/CFT, to a non-equilibrium approach to the conformal phase transition. We comment on a class of initial conditions that generically leads to completion of the phase transition without sacrificing perturbativity of the 5D theory.

   hep-phastro-ph.COhep-thEPJC(2024)·16 citations
2. 02*

   Exploring the viability of pseudo Nambu-Goldstone boson as ultralight dark matter in a mass range relevant for strong gravity applications

   António P. Morais🇨🇭 · Vinícius Oliveira🇧🇷 · António Onofre🇵🇹 · Roman Pasechnik🇸🇪 · Rui Santos🇵🇹

   We study a simple extension of the Standard Model featuring a dark sector with an ultralight pseudo Nambu-Goldstone boson as dark matter candidate. We focus on the mass range $\mathcal{O}(10^{-20}-10^{-10})$ eV, relevant for strong gravity applications, and explore its production and evolution in the early Universe. The model is formulated in such a way that dark matter does not couple directly to photons or other Standard Model particles avoiding some of the most stringent cosmological bounds related to axion-like particles. In this work, two different scenarios are considered depending on whether dark matter is produced in a pre-inflationary or post-inflationary regime. We also discuss the effect from emergent topological defects such as cosmic strings and domain walls, and estimate the spectrum of stochastic gravitational waves produced by their decay, enabling to test the model at current and future gravitational-wave experiments.

   hep-phastro-ph.HEgr-qchep-thPRD(2024)·3 citations
3. 03*

   NLO QCD predictions for off-shell $t\bar{t}W$ production in association with a light jet at the LHC

   Huan-Yu Bi🇨🇳 · Manfred Kraus🇲🇽 · Minos Reinartz🇩🇪 · Malgorzata Worek🇩🇪

   In view of the persisting tension between theoretical predictions and the LHC data for the $pp\to t\bar{t}{W}^{\pm }$ production process, we present the state-of-the-art full off-shell NLO QCD result for $pp\to t\bar{t}{W}^{+}j+X$. We concentrate on the multi-lepton decay channel at the LHC with $\sqrt{s}=13$ TeV. In our calculation off-shell top quarks and gauge bosons are described by Breit-Wigner propagators, furthermore, double-, single- as well as non-resonant top-quark contributions along with all interference effects are consistently incorporated at the matrix element level. We present results for both integrated and differential fiducial cross sections for various renormalisation and factorisation scale settings and different PDF sets. With a fairly inclusive choice of cuts and regardless of the scale and PDF choice, non-flat differential $\mathcal{K}$-factors are obtained for many observables that we have examined. Since from an experimental point of view, both processes $pp\to t\bar{t}{W}^{\pm }j+X$ and $pp\to t\bar{t}{W}^{\pm }+X$ consist of similar final states we investigate the effect of additional jet activity on the integrated and differential fiducial cross sections. For this purpose, the normalised differential distributions for $pp\to e^{+}{\nu }_e{\mu }^{-}{\bar{\nu }}_{\mu }{\tau }^{+}{\nu }_{\tau }b\bar{b}j+X$ and $pp\to e^{+}{\nu }_e{\mu }^{-}{\bar{\nu }}_{\mu }{\tau }^{+}{\nu }_{\tau }b\bar{b}+X$ are compared. The theoretical results for the latter process are also recalculated.

   hep-phhep-exJHEP(2023)·10 citations
4. 04*

   Strong-Field Physics in QED and QCD: From Fundamentals to Applications

   Koichi Hattori🇨🇳 · Kazunori Itakura🇯🇵 · Sho Ozaki🇯🇵

   We provide a pedagogical review article on fundamentals and applications of the quantum dynamics in strong electromagnetic fields in QED and QCD. The fundamentals include the basic picture of the Landau quantization and the resummation techniques applied to the class of higher-order diagrams that are enhanced by large magnitudes of the external fields. We then discuss observable effects of the vacuum fluctuations in the presence of the strong fields, which consist of the interdisciplinary research field of nonlinear QED. We also discuss extensions of the Heisenberg-Euler effective theory to finite temperature/density and to non-Abelian theories with some applications. Next, we proceed to the paradigm of the dimensional reduction emerging in the low-energy dynamics in the strong magnetic fields. The mechanisms of superconductivity, the magnetic catalysis of the chiral symmetry breaking, and the Kondo effect are addressed from a unified point of view in terms of the renormalization-group method. We provide an up-to-date summary of the lattice QCD simulations in magnetic fields for the chiral symmetry breaking and the related topics as of the end of 2022. Finally, we discuss novel transport phenomena induced by chiral anomaly and the axial-charge dynamics. Those discussions are supported by a number of appendices.

   hep-phastro-ph.HEcond-mat.str-elhep-lat+1PPNP(2023)·67 citations
5. 05*

   Probing Lepton Flavor Violation at Circular Electron-Positron Colliders

   Wolfgang Altmannshofer🇺🇸 · Pankaj Munbodh🇺🇸 · Talise Oh🇺🇸

   Lepton flavor violation is one of the cleanest probes of physics beyond the standard model. In this work, we explore the sensitivity of the process $e^{+}{e}^{-}\to \tau \mu$ to new physics above the TeV scale at the proposed circular electron-positron colliders FCC-ee and CEPC. We compute the $e^{+}{e}^{-}\to \tau \mu$ cross-section in the Standard Model Effective Field Theory and assess the relevant backgrounds. We compare our sensitivity projections to existing and expected constraints from tau decays and $Z$ decays and find that the future electron-positron colliders provide competitive probes of new physics. We highlight the complementarity of searches for resonant $e^{+}{e}^{-}\to Z\to \tau \mu$ production on the $Z$ pole and searches for non-resonant $e^{+}{e}^{-}\to \tau \mu$ at higher center-of-mass energies.

   hep-phJHEP(2023)·26 citations
6. 06*

   On the relation between $K_s^0$ and charged kaon yields in proton-proton collisions

   Joanna Stepaniak🇵🇱 · Damian Pszczel🇵🇱

   A compilation of the experimental p+p data of neutral and charged kaon production has revealed a discrepancy between the observed $K_s^0$ yield and the average number of produced charged kaons $K_s^0=(K^{+}+K^{-})/2$. This widespread relation holds only for a colliding system that is an uniform population w.r. to the isospin (i.e. that consists of an equal number of all members of a given isospin multiplet). This is not the case for p+p collisions therefore one should not expect that it will describe the data accurately. A much better agreement is obtained with a model based on the quark structure of the participating hadrons.

   hep-phEPJC(2023)·6 citations
7. 07*

   $\varphi (2170)$ decaying to $\varphi \eta$ and $\varphi {\eta }^{\prime }$

   Brenda B. Malabarba🇧🇷 · K. P. Khemchandani🇧🇷 · A. Martinez Torres🇧🇷

   In this work we calculate the decay widths of $\varphi (2170)$ to $\varphi \eta$ and $\varphi {\eta }^{\prime }$ by considering $\varphi (2170)$ as a $\varphi K\bar{K}$ state, with $K\bar{K}$ clustering as $f_0(980)$. These decay widths have been recently determined by the BESIII, BaBar and Belle collaborations with the aim of unraveling the nature of $\varphi (2170)$. By analyzing the data on the cross sections of the process $e^{+}{e}^{-}\to \varphi \eta$, two solutions were found by the BESIII collaboration with the same ${\chi }^2/n.d.f$, mass and width for $\varphi (2170)$. However, different values for ${\mathcal{B}}_{\varphi \eta }^{\varphi (2170)}{\Gamma }_{e^{+}{e}^{-}}^{\varphi (2170)}$ were obtained: $0.24_{-0.07}^{+0.12}$ eV (solution I) and $10.11_{-3.13}^{+3.87}$ eV (solution II). In case of ${\mathcal{B}}_{\varphi {\eta }^{\prime }}^{\varphi (2170)}{\Gamma }_{e^{+}{e}^{-}}^{\varphi (2170)}$, a value of $7.1\pm 0.7\pm 0.7$ was determined by the BESIII collaboration from fits to the data on the cross section of $e^{+}{e}^{-}\to \varphi {\eta }^{\prime }$. The Belle collaboration has also determined ${\mathcal{B}}_{\varphi \eta }^{\varphi (2170)}{\Gamma }_{e^{+}{e}^{-}}^{\varphi (2170)}$ more recently, although the statistical significance related to the signal of $\varphi (2170)$ in the data is low. We calculate the decay widths of $\varphi (2170)$ to $\varphi \eta$ and $\varphi {\eta }^{\prime }$, and compare their ratio ${\Gamma }_{\varphi \eta }^{\varphi (2170)}/{\Gamma }_{\varphi {\eta }^{\prime }}^{\varphi (2170)}$ with the one determined by using the above mentioned experimental data. Considering the theoretical and experimental uncertainties, the lower limit of our theoretical result ($\simeq 2.6$) is close to the upper value obtained ($\simeq 2$) by using the solution II of BESIII for ${\mathcal{B}}_{\varphi \eta }^{\varphi (2170)}{\Gamma }_{e^{+}{e}^{-}}^{\varphi (2170)}$, as well as to the upper limit found ($\simeq 2.8$) when considering the solutions III and IV of the Belle collaboration for ${\mathcal{B}}_{\varphi \eta }^{\varphi (2170)}{\Gamma }_{e^{+}{e}^{-}}^{\varphi (2170)}$.

   hep-phnucl-thPRD(2023)·11 citations
8. 08*

   Generalized hybrid natural inflation

   Teruyuki Kitabayashi🇯🇵

   Although the hybrid natural inflation is a successful inflation model, the symmetry breaking scale in the model should be large for a negative value of the running of the scalar spectral index. This study proposed a generalized hybrid natural inflation model that can realize a low-scale inflation with a negative value of the running of the scalar spectral index.

   hep-phPRD(2023)·5 citations
9. 09*

   Can we discover lepton number violation with LHC far detectors?

   Ying-nan Mao🇨🇳 · Kechen Wang🇨🇳 · Zeren Simon Wang🇹🇼

   Two classes of far detectors have been proposed or are under operation at the LHC. The first class is a series of neutrino detectors that are sensitive to light active neutrinos via either charged-current or neutral-current interactions; exemplary ideas are FASER$\nu$, SND@LHC, and FLArE. Another type aims primarily at looking for displaced decays of long-lived particles (LLPs) into charged final-state particles, including ANUBIS and FASER. In this work, we propose searches for probing lepton number violation associated with a Majorana active/sterile neutrino, for the first time with these experiments, which, if discovered, would be a clear signature of new physics beyond the Standard Model. With Monte-Carlo simulation, we find that while the neutrino detectors, unfortunately, are estimated to have signal-event rates orders of magnitude below $\mathcal{O}(1)$, some LLP far detectors such as ANUBIS, if upgraded, would be most promising for discovering a Majorana sterile neutrino of mass $\mathcal{O}(\text{1})$ GeV in certain so-far unexcluded parameter space. In this exploratory work, we emphasize on the importance of leveraging the LHC far detectors for purposes beyond the planned ones, such as searching for lepton number violation.

   hep-phhep-exPRD(2023)·4 citations
10. 10*

    One-loop expressions for $h\to l\bar{l}\gamma$ in Higgs extensions of the Standard Model

    L. T. Hue (VLU)🇻🇳 · Dzung Tri Tran (DTU)🇻🇳 · Thanh Huy Nguyen (HCMUS)🇻🇳 · Khiem Hong Phan (DTU)🇻🇳

    A systematic study of one-loop contributions to the decay channels $h\to l\bar{l}\gamma$ with $l={\nu }_{e,\mu ,\tau },e,\mu$, performed in Higgs extended versions of the Standard Model, is presented in the 't Hooft-Veltman gauge. Analytic formulas for one-loop form factors are expressed in terms of the logarithm and di-logarithmic functions. As a result, these form factors can be reduced to those relating to the loop-induced decay processes $h\to \gamma \gamma ,Z\gamma$, confirming not only previous results using different approaches but also close relations between the three kinds of the loop-induced Higgs decay rates. For phenomenological study, we focus on the two observables, namely the enhancement factors defined as ratios of the decay rates calculated between the Higgs extended versions and the standard model, and the forward-backward asymmetries of fermions, which can be used to search for Higgs extensions of the SM. We show that direct effects of mixing between neutral Higgs bosons and indirect contributions of charged Higg boson exchanges can be probed at future colliders.

    hep-phPTEP(2023)·11 citations
11. 11*

    TMD parton showers for associated $\gamma$+jet production in electron-proton collisions at high energies

    A. V. Lipatov🇷🇺 · M. A. Malyshev🇷🇺

    An earlier developed $k_T$-factorization framework to calculate the associated prompt photon and hadronic jets production cross sections at high energies is extended now to the electron-proton deep inelastic scattering. The proposed method is based on joint usage of the PEGASUS and CASCADE Monte-Carlo event generators, which deal with the transverse momentum dependent (TMD) gluon and quark densities in a proton. First of them, PEGASUS, is applied to produce off-shell photon-gluon fusion events. Then, to properly simulate the kinematics of the produced jets, the TMD parton shower algorithm implemented into the CASCADE is used. We demonstrate basic features of the approach considering latest H1 and ZEUS data on prompt photon plus jet production at low $Q^2$ collected at HERA. We achieve a good description of the measurements and point out that a correct simulation of parton showers is essential for studying non-inclusive processes at high energies within the TMD-based approaches.

    hep-phPRD(2023)·11 citations
12. 12*

    One-loop formulas for off-shell decay $H^{\ast }\to W^{+}{W}^{-}$ in 't Hooft-Veltman gauge and its applications

    Khiem Hong Phan (DTU)🇻🇳 · Dzung Tri Tran (DTU)🇻🇳 · Anh Thu Nguyen (HCMUS)🇻🇳

    We present analytic results for one-loop radiative corrections to off-shell decay $H^{\ast }\to W^{+}{W}^{-}$ in 't Hooft-Veltman gauge within Standard Model framework. In numerical results, we show off-shell decay rate and its corrections with varying off-shell Higgs mass. The results show that the corrections are of $10\%$ contributions to total decay rates. Furthermore, we study the impacts of one-loop radiative corrections to off-shell decay $H^{\ast }\to W^{+}{W}^{-}$ in Higgs processes at future colliders. The signal processes such as $e^{-}{e}^{+}\to Z{H}^{\ast }\to Z(WW)$ with including the initial beam polarizations and $e^{-}{e}^{+}\to {\nu }_e{\bar{\nu }}_e{H}^{\ast }\to {\nu }_e{\bar{\nu }}_e(WW)$ and $e^{-}\gamma \to e^{-}{H}^{\ast }\to e^{-}WW$ are examined. We find that the effects are visible impacts and these should be taken into account at future colliders.

    hep-phCommun.in Phys.(2023)·3 citations
13. 13*

    Propagation of angular momentum in charged pion decay and related processes

    Bowen Wang🇨🇳

    There are confusions about angular momentum propagation in scattering or decay processes involving the transition between particle systems that appear to transform differently under Lorentz transformations. This paper provides an analysis of the transformation properties of the states and interactions for a few typical processes within the standard model of particle physics, and performs explicit calculations showing how angular momentum transfers in these processes. We shall show that angular momentum conservation is completely consistent with the calculation in quantum field theory.

    hep-phEur.Phys.J.Plus(2023)·0 citations
14. 14*

    Nonlinear terms from GLR-MQ evolution

    G.R.Boroun🇮🇷

    We show that the saturation exponent is more effective than the hard pomeron exponent in the nonlinear terms for the GLR-MQ evolution equations. For the gluon distribution the nonlinear terms are found to play an increasingly important role than the singlet distribution. The nonlinear corrections for the singlet and gluon distributions are important in a limited range of $Q^2$ and are independent of the upward and downward evolution. This allows us to single out the region where the nonlinear corrections may provide evidence for recombination. We numerically study the nonlinear terms for nuclear singlet and gluon distributions and quantify the impact of gluon recombination in a wide range of $Q^2$. This analysis indicates that the nonlinear effects are most pronounced for heavy nuclei and are sizable at $2\lesssim Q^2\lesssim 20{\mathrm{GeV}}^2$ for light and heavy nuclei.

    hep-phPramana(2025)·8 citations
15. 15*

    Decay properties of $D_{s0}^{\ast }(2317{)}^{+}$ as a conventional $c\bar{s}$ meson

    Meng Han🇨🇳 · Wei Li🇨🇳 · Su-Yan Pei🇨🇳 · Ting-Ting Liu🇨🇳 · Guo-Li Wang🇨🇳

    Taking $D_{s0}^{\ast }(2317{)}^{+}$ as a conventional $c\bar{s}$ meson, we calculate its dominant strong and electromagnetic decays in the framework of the Bethe-Salpeter method. Our results are $\Gamma (D_{s0}^{\ast +}\to D_s^{+}{\pi }^0)=7.83_{-1.55}^{+1.97}$ keV and $\Gamma (D_{s0}^{\ast +}\to D_s^{\ast +}\gamma )=2.55_{-0.45}^{+0.37}$ keV. The contributions of the different partial waves from the initial and final state wave functions to the decay width are also calculated, and we find that the relativistic corrections in both decay processes are very large.

    hep-phCPC(2023)·5 citations
16. 16*

    Double DVCS as a window to the complete mapping of GPDs

    K. Deja🇵🇱 · V. Martinez-Fernandez🇵🇱 · B. Pire🇫🇷 · P. Sznajder🇵🇱 · J. Wagner🇵🇱

    Double deeply virtual Compton scattering (DDVCS) is the process where an electron scatters off a nucleon and produces a lepton pair. The main advantage of this process in contrast with deeply virtual and timelike Compton scatterings (DVCS and TCS) is the possibility of directly measuring GPDs for $x\ne \pm \xi$ at leading order in ${\alpha }_s$ (LO). We present a new calculation of the DDVCS amplitude based on spinor techniques which produce expressions for amplitudes that are perfectly suited for their implementation in numerical simulations. Elements of impact studies, including predictions for experiments at JLab12, JLab20+ and the Electron-Ion Collider (EIC), are studied by means of the PARTONS software and the EpIC Monte Carlo event generator.

    hep-phhep-exnucl-exnucl-th2 citations
17. 17*

    Precise predictions for polarised weak bosons at the LHC

    Giovanni Pelliccioli🇩🇪

    Precise and accurate Standard Model predictions are needed for polarised weak bosons in LHC processes, in order to perform template fits of data and to enhance the sensitivity to possible new-physics effects. We have proposed a general strategy to compute polarised cross-sections including radiative QCD and electroweak corrections to the production and decay of bosons. The method relies on the pole approximation and the separation of polarisation states at amplitude level. After showing some details of the theoretical definition, we present results relevant for LHC di-boson polarisation analyses in semi-leptonic decay channels.

    hep-ph0 citations
18. 18*

    Searching for dark jets with displaced vertices using weakly supervised machine learning

    Debjyoti Bardhan🇮🇱 · Yevgeny Kats🇮🇱 · Noam Wunch🇮🇱

    If "dark quarks" from a confining hidden sector are produced at the LHC, they will shower and hadronize to dark sector hadrons, which may decay back to Standard Model particles within the detector, possibly resulting in a collimated spray of particles resembling a QCD jet. In this work we address scenarios in which dark hadrons decay with a measurable small displacement, such that the relevant background is dominated by heavy-flavor jets. Since dark sector parameters are largely unconstrained, and the precise properties of a dark QCD-like theory are difficult to compute or simulate reliably in any case, model-independent, data-based searches for such scenarios are desirable. We explore a search strategy employing weakly supervised machine learning to search for anomalous jets with displaced vertices. The method is tested on several toy signals, demonstrating the feasibility of such a search. Our approach has potential to outperform simple cut-based methods in some cases and has the advantage of being more model-independent.

    hep-phPRD(2023)·9 citations
19. 19*

    On Evaluation of Nonfactorizable Corrections to Higgs Boson Production via Vector Boson Fusion

    Logan Gates🇨🇦

    We present the fully analytical result for the next-to-next-to-leading nonfactorizable QCD corrections to Higgs boson production via vector boson fusion computed to the leading power in the ratio of the jet transverse momentum to the partonic center-of-mass energy.

    hep-phPLB(2023)·6 citations
20. 20*

    Threshold resummation for computing large-$x$ parton distribution through large-momentum effective theory

    Xiangdong Ji🇺🇸 · Yizhuang Liu🇵🇱 · Yushan Su🇺🇸

    Parton distribution functions (PDFs) at large $x$ are poorly constrained by high-energy experimental data, but extremely important for probing physics beyond standard model at colliders. We study the calculation of PDFs at large-$x$ through large-momentum $P^z$ expansion of the lattice quasi PDFs. Similar to deep-inelastic scattering, there are two distinct perturbative scales in the threshold limit where the matching coefficient can be factorized into a space-like jet function at scale $P^z|1-y|$ and a pair of heavy-light Sudakov form factors at scale $P^z$. The matching formula allows us to derive a full renormalization group resummation of large threshold logarithms, and the result is consistent with the known calculation to the next-to-next to leading order (NNLO). This paves the way for direct large-$x$ PDFs calculations in lattice QCD. As by-products, we find that the space-like jet function is related to a time-like version calculated previously through analytic continuation, and the heavy-light Sudakov form factor, calculated here to NNLO, is a universal object appearing as well in the large momentum expansion of quasi transverse-momentum-dependent PDFs and quasi wave-function amplitudes.

    hep-phhep-lathep-thnucl-thJHEP(2023)·40 citations
21. 21*

    The $X(6550),X(6900),X(7280)$ resonances as the $nS,cc\bar{c}\bar{c}$ states

    A. M. Badalian🇷🇺

    \date{\today} Within the diquark-antidiquark model the masses of the $0^{++},cc\bar{c}\bar{c}$ resonances are calculated, using the expansion of the four-quark wave function in the set of the hyperspherical functions. The interaction is defined via a universal pair-wise potential, which does not contain fitting parameters. The resulting masses $M_4(nS)$ are shown to be very sensitive to the value of $c-$quark mass, chosen in relativistic string Hamiltonian, and $m_c=1.24,1.30,1.43$ (in GeV) are considered. The choice of $m_c$, equal to the current mass, $m_c=1.245$ GeV, yields three $nS(n_r=0,1,2)$ states in a very good agreement with the masses of the $X(6550),X(6900),X(7287)$ resonances, if the gluon-exchange interaction is totally neglected. This fact indicates on a possible screening of the gluon-exchange interaction inhe $cc\bar{c}\bar{c}$ system. For $m_c=1.43$~GeV the ground state mass $M_4(1S)=6557$~MeV is obtained in agreement with experiment only if ${\alpha }_{\mathrm{V}}\cong 0.39(1)$ is used, however, in this case the masses of the $2S,3S$ radial excitations exceed the masses of $X(6900),X(7280)$ by $\sim 100$~MeV.

    hep-phhep-exhep-lat1 citation
22. 22*

    Explaining the Muon g-2 Anomaly in Deflected AMSB for NMSSM

    Li-Jun Jia🇨🇳 · Zhuang Li🇨🇳 · Fei Wang🇨🇳

    We propose to embed the General NMSSM (Next-to-Minimal Supersymmetric Standard Model) into the deflected AMSB (Anomaly Mediated Supersymmetry Breaking) mechanism with Yukawa/gauge deflection contributions. After integrating out the heavy messenger fields, the analytical expressions of the relevant soft SUSY breaking spectrum for General NMSSM at the messenger scale can be calculated. We find that successful EWSB (Electroweak Symmetry Breaking) and realistic low energy NMSSM spectrum can be obtained in some parameter regions. In addition, we find that the muon $g-2$ anomaly and electron $g-2$ anomaly (for positive central value electron $g-2$ experimental data) can be jointly explained to $1\sigma$ and $2\sigma$ range, respectively. The $Z_3$ invariant NMSSM, which corresponds to ${\xi }_F=0$ in our case, can also jointly explain the muon and electron anomaly to $1\sigma$ and $2\sigma$ range, respectively.

    hep-phUniverse(2023)·7 citations
23. 23*

    CURTAINs Flows For Flows: Constructing Unobserved Regions with Maximum Likelihood Estimation

    Debajyoti Sengupta🇨🇭 · Samuel Klein🇨🇭 · John Andrew Raine🇨🇭 · Tobias Golling🇨🇭

    Model independent techniques for constructing background data templates using generative models have shown great promise for use in searches for new physics processes at the LHC. We introduce a major improvement to the CURTAINs method by training the conditional normalizing flow between two side-band regions using maximum likelihood estimation instead of an optimal transport loss. The new training objective improves the robustness and fidelity of the transformed data and is much faster and easier to train. We compare the performance against the previous approach and the current state of the art using the LHC Olympics anomaly detection dataset, where we see a significant improvement in sensitivity over the original CURTAINs method. Furthermore, CURTAINsF4F requires substantially less computational resources to cover a large number of signal regions than other fully data driven approaches. When using an efficient configuration, an order of magnitude more models can be trained in the same time required for ten signal regions, without a significant drop in performance.

    hep-phcs.LGhep-exSciPost Phys.(2024)·52 citations
24. 24*

    Beyond the Standard Model physics in the far-forward region of the Large Hadron Collider

    Sebastian Trojanowski🇵🇱

    A new physics program has been initiated as part of the ongoing LHC physics run in the far-forward region, where dedicated FASER and SND@LHC experiments are currently taking data. We discuss the possible discovery prospects of this program in the search for signatures of beyond the Standard Model physics. We focus on both the present period and the proposed future Forward Physics Facility (FPF) that will operate in the high luminosity LHC era.

    hep-phActa Phys.Polon.Supp.(2023)·1 citation
25. 25*

    Phenomenology of a minimal extension of the standard model with a family-dependent gauge symmetry

    Duong Van Loi🇻🇳 · Cao H. Nam🇻🇳 · Phung Van Dong🇻🇳

    We consider a gauge symmetry extension of the standard model given by $SU(3{)}_C\otimes SU(2{)}_L\otimes U(1{)}_X\otimes U(1{)}_N\otimes Z_2$ with minimal particle content, where $X$ and $N$ are family dependent but determining the hypercharge as $Y=X+N$, while $Z_2$ is an exact discrete symmetry. In our scenario, $X$ (while $N$ is followed by $X-Y$) and $Z_2$ charge assignments are inspired by the number of fermion families and the stability of dark matter, as observed, respectively. We examine the mass spectra of fermions, scalars, and gauge bosons, as well as their interactions, in presence of a kinetic mixing term between $U(1{)}_{X,N}$ gauge fields. We discuss in detail the phenomenology of the new gauge boson and the right-handed neutrino dark matter stabilized by $Z_2$ conservation. We obtain parameter spaces simultaneously satisfying the recent CDF $W$-boson mass, electroweak precision measurements, particle colliders, as well as dark matter observables, if the kinetic mixing parameter is not necessarily small.

    hep-phPRD(2023)·6 citations
26. 26*

    Exploring light dark matter with the Migdal effect in hydrogen-doped liquid xenon

    Nicole F. Bell🇦🇺 · Peter Cox🇦🇺 · Matthew J. Dolan🇦🇺 · Jayden L. Newstead🇦🇺 · Alexander C. Ritter🇦🇺

    An ongoing challenge in dark matter direct detection is to improve the sensitivity to light dark matter in the MeV--GeV mass range. One proposal is to dope a liquid noble-element direct detection experiment with a lighter element such as hydrogen. This has the advantage of enabling larger recoil energies compared to scattering on a heavy target, while leveraging existing detector technologies. Direct detection experiments can also extend their reach to lower masses by exploiting the Migdal effect, where a nuclear recoil leads to electronic ionisation or excitation. In this work we combine these ideas to study the sensitivity of a hydrogen-doped LZ experiment (HydroX), and a future large-scale experiment such as XLZD. We find that HydroX could have sensitivity to dark matter masses as low as 5~MeV for both spin-independent and spin-dependent scattering, with XLZD extending that reach to lower cross sections. Notably, this technique substantially enhances the sensitivity of direct detection to spin-dependent proton scattering, well beyond the reach of any current experiments.

    hep-phhep-exPRD(2024)·18 citations
27. 27*

    Evolution and interpolation of double parton distributions using Chebyshev grids

    Markus Diehl🇩🇪 · Riccardo Nagar🇮🇹 · Peter Ploessl🇩🇪 · Frank J. Tackmann🇩🇪

    Double parton distributions are the nonperturbative ingredients needed for computing double parton scattering processes in hadron-hadron collisions. They describe a variety of correlations between two partons in a hadron and depend on a large number of variables, including two independent renormalization scales. This makes it challenging to compute their scale evolution with satisfactory numerical accuracy while keeping computational costs at a manageable level. We show that this problem can be solved using interpolation on Chebyshev grids, extending the methods we previously developed for ordinary single-parton distributions. Using an implementation of these methods in the C++ library ChiliPDF, we study for the first time the evolution of double parton distributions beyond leading order in perturbation theory.

    hep-phEPJC(2023)·9 citations
28. 28*

    Neutrino many-body correlations

    Lucas Johns🇺🇸

    This paper responds to suggestions that the standard approach to collective neutrino oscillations leaves out potentially important quantum many-body correlations. Arguments in favor of this idea have been based on calculations that, on close scrutiny, offer no evidence either way. Inadequacies of the usual quantum-kinetic formalism are not currently supported by the literature.

    hep-phastro-ph.HEInt.J.Mod.Phys.A(2024)·33 citations
29. 29*

    Primordial Black Holes from Supercooled Phase Transitions

    Yann Gouttenoire🇮🇱 · Tomer Volansky🇮🇱

    Cosmological first-order phase transitions (1stOPTs) are said to be strongly supercooled when the nucleation temperature is much smaller than the critical temperature. These are often encountered in theories that admit a nearly scale-invariant potential, for which the bounce action decreases only logarithmically with temperature. During supercooled 1stOPTs the equation of state of the universe undergoes a rapid and drastic change, transitioning from vacuum-domination to radiation-domination. The statistical variations in bubble nucleation histories imply that distinct causal patches percolate at slightly different times. Patches which percolate the latest undergo the longest vacuum-domination stage and as a consequence develop large over-densities triggering their collapse into primordial black holes (PBHs). We derive an analytical approximation for the probability of a patch to collapse into a PBH as a function of the 1stOPT duration, ${\beta }^{-1}$, and deduce the expected PBH abundance. We find that 1stOPTs which take more than $15\%$ of a Hubble time to complete ($\beta /H\lesssim 7$) produce observable PBHs. Their abundance is independent of the duration of the supercooling phase, in agreement with the de Sitter no hair conjecture.

    hep-phastro-ph.COPRD(2024)·152 citations
30. 30*

    Dark Matter Direct Detection on the Moon

    Andrea Gaspert🇺🇸 · Pietro Giampa🇨🇦 · Navin McGinnis🇨🇦 · David E. Morrissey🇨🇦

    Direct searches for dark matter with large-scale noble liquid detectors have become sensitive enough to detect the coherent scattering of local neutrinos. This will become a very challenging background to dark matter discovery in planned future detectors. For dark matter with mass above 10 GeV, the dominant neutrino backgrounds on the Earth are atmospheric neutrinos created by cosmic ray collisions with the atmosphere. In contrast, the Moon has almost no atmosphere and nearly all cosmic rays incident on the Moon first collide with the lunar surface, producing a very different neutrino spectrum. In this work we estimate the total flux and spectrum of neutrinos near the surface of the Moon. We then use this to show that a large-scale liquid xenon or argon detector located on the Moon could potentially have significantly greater sensitivity to dark matter compared to an equivalent detector on the Earth due to effectively reduced neutrino backgrounds.

    hep-phhep-exPRD(2023)·4 citations
31. 31*

    Gradient Boosting MUST taggers for highly-boosted jets

    J. A. Aguilar-Saavedra🇪🇸 · E. Arganda🇪🇸 · F. R. Joaquim🇵🇹 · R. M. Sandá Seoane🇪🇸 · J. F. Seabra🇪🇸

    The MUST (Mass Unspecific Supervised Tagging) method has proven to be successful in implementing generic jet taggers capable of discriminating various signals over a wide range of jet masses. We implement the MUST concept by using eXtreme Gradient Boosting (XGBoost) classifiers instead of neural networks (NNs) as previously done. We build both fully-generic and specific multi-pronged taggers, to identify 2, 3, and/or 4-pronged signals from SM QCD background. We show that XGBoost-based taggers are not only easier to optimize and much faster than those based in NNs, but also show quite similar performance, even when testing with signals not used in training. Therefore, they provide a quite efficient alternative machine-learning implementation for generic jet taggers.

    hep-phhep-exEur.Phys.J.Plus(2024)·10 citations
32. 32*

    Phenomenology of wavelike vector dark matter nonminimally coupled to gravity

    Hong-Yi Zhang🇺🇸 · Siyang Ling🇺🇸

    We study three astrophysical/cosmological consequences of nonminimal couplings to gravity in wavelike vector dark matter. In the nonrelativistic limit, the nonminimal coupling with the lowest mass dimension leads to effective self-interactions that affect the mass-radius relation of vector solitons, growth of linear perturbations during structure formation, and the speed of gravitational waves (GWs). Based on the success of cold dark matter on large-scale perturbations and the current limits on GW speed, we constrain the dark matter mass and nonminimal coupling strength to be within the range $|{\xi }_1|/m^2\ll 10^{50}\mathrm{e}{\mathrm{V}}^{-2}$ and $-3\times 10^{46}\mathrm{e}{\mathrm{V}}^{-2}\lesssim {\xi }_2/m^2\lesssim 8\times 10^{48}\mathrm{e}{\mathrm{V}}^{-2}$.

    ↳ astro-ph.COhep-phJCAP(2023)·15 citations
33. 33*

    Generalized Linear Models of T${}_{90}$-T${}_{50}$ relation to classify GRBs

    Sourav Dutta🇮🇳 · Sunanda🇮🇳 · Reetanjali Moharana🇮🇳 · Manish Kumar🇮🇳

    Gamma-ray bursts (GRBs) can be classified with their linearly dependent parameters alongside the standard $T_{90}$ distribution. The Generalized linear mixture model(GLM) identifies the number of linear dependencies in a two-parameter space. Classically, GRBs are classified into two classes by the presence of bimodality in the histogram of T${}_{90}$. However, additional classes and sub-classes of GRBs are fascinating topics to explore. In this work, we investigate the GRBs classes in the $T_{90}-T_{50}$ plane using the Generalized Linear Models(GLM) for Fermi GBM and BATSE catalogs. This study shows five linear features for the Fermi GBM catalog and four linear features for the BATSE catalog, directing towards the possibility of more than two GRB classes.

    ↳ astro-ph.HEhep-phMNRAS(2024)·2 citations
34. 34*

    Lattice calculation of the ${\pi }^0$, $\eta$ and ${\eta }^{\prime }$ transition form factors and the hadronic light-by-light contribution to the muon $g-2$

    Antoine Gérardin🇫🇷 · Willem E. A. Verplanke🇫🇷 · Gen Wang🇫🇷 · Zoltan Fodor🇩🇪 · Jana N. Guenther🇩🇪 · Laurent Lellouch🇫🇷 · Kalman K. Szabo🇩🇪 · Lukas Varnhorst🇩🇪

    In this paper we present a first ab-initio calculation of the ${\pi }^0$, $\eta$ and ${\eta }^{\prime }$ transition form factors performed with physical light-quark masses. We provide a complete parametrization of the form factors that includes both single and double-virtual kinematics. Our results are compared with experimental measurements of the form factors in the space-like region and with the measured two-photon decay widths. In a second step, our parametrizations of the transition form factors are used to compute the dominant pseudoscalar-pole contributions to the hadronic light-by-light scattering in the muon $g-2$. Our final result reads $a_{\mu }^{\mathrm{hlbl},\mathrm{ps}-\mathrm{pole}}=(85.1\pm 5.2)\times 10^{-11}$. Although the pion-pole is dominant, we confirm that, together, the $\eta$ and ${\eta }^{\prime }$ provide roughly half of its contribution.

    ↳ hep-lathep-phPRD(2025)·49 citations
35. 35*

    Fractal derivatives, fractional derivatives and $q$-deformed calculus

    Airton Deppman🇧🇷 · Eugenio Megias🇪🇸 · Roman Pasechnik🇸🇪

    This work presents an analysis of fractional derivatives and fractal derivatives, discussing their differences and similarities. The fractal derivative is closely connected to Haussdorff's concepts of fractional dimension geometry. The paper distinguishes between the derivative of a function on a fractal domain and the derivative of a fractal function, where the image is a fractal space. Different continuous approximations for the fractal derivative are discussed, and it is shown that the $q$-calculus derivative is a continuous approximation of the fractal derivative of a fractal function. A similar version can be obtained for the derivative of a function on a fractal space. Caputo's derivative is also proportional to a continuous approximation of the fractal derivative, and the corresponding approximation of the derivative of a fractional function leads to a Caputo-like derivative. This work has implications for studies of fractional differential equations, anomalous diffusion, information and epidemic spread in fractal systems, and fractal geometry.

    ↳ math-phhep-phmath.MPnlin.AO+2Entropy(2023)·10 citations
36. 36*

    Dense Baryonic Matter Predicted in "Pseudo-Conformal Model"

    Mannque Rho🇫🇷

    The World-Class University/Hanyang Project launched in Korea in 2007 led to what's now called ``pseudo-conformal model" that addresses dense compact-star matter and is confronted in this short note with the presently available astrophysical observables, with focus on those from gravity waves. The predictions made nearly free of parameters by the model involving ``topology change" remain more or less intact ``un-torpedoed" by the data.

    ↳ nucl-thhep-phSymmetry(2023)·9 citations
37. 37*

    Octet baryon isovector charges from $N_f=2+1$ lattice QCD

    Gunnar S. Bali🇩🇪 · Sara Collins🇩🇪 · Simon Heybrock🇸🇪 · Marius Löffler🇩🇪 · Rudolf Rödl🇩🇪 · Wolfgang Söldner🇩🇪 · Simon Weishäupl🇩🇪

    We determine the axial, scalar and tensor isovector charges of the nucleon, sigma and cascade baryons as well as the difference between the up and down quark masses, $m_u-m_d$. We employ gauge ensembles with $N_f=2+1$ non-perturbatively improved Wilson fermions at six values of the lattice spacing in the range $a\approx (0.039-0.098)$fm, generated by the Coordinated Lattice Simulations (CLS) effort. The pion mass $M_{\pi }$ ranges from around $430$MeV down to a near physical value of $130$MeV and the linear spatial lattice extent $L$ varies from $6.5M_{\pi }^{-1}$ to $3.0M_{\pi }^{-1}$, where $L{M}_{\pi }\ge 4$ for the majority of the ensembles. This allows us to perform a controlled interpolation/extrapolation of the charges to the physical mass point in the infinite volume and continuum limit. Investigating SU(3) flavour symmetry, we find moderate symmetry breaking effects for the axial charges at the physical quark mass point, while no significant effects are found for the other charges within current uncertainties.

    ↳ hep-lathep-phPRD(2023)·60 citations
38. 38*

    CaloClouds: Fast Geometry-Independent Highly-Granular Calorimeter Simulation

    Erik Buhmann🇩🇪 · Sascha Diefenbacher🇩🇪 · Engin Eren🇩🇪 · Frank Gaede🇩🇪 · Gregor Kasieczka🇩🇪 · Anatolii Korol🇩🇪 · William Korcari🇩🇪 · Katja Krüger🇩🇪 · Peter McKeown🇩🇪

    Simulating showers of particles in highly-granular detectors is a key frontier in the application of machine learning to particle physics. Achieving high accuracy and speed with generative machine learning models would enable them to augment traditional simulations and alleviate a major computing constraint. This work achieves a major breakthrough in this task by, for the first time, directly generating a point cloud of a few thousand space points with energy depositions in the detector in 3D space without relying on a fixed-grid structure. This is made possible by two key innovations: i) Using recent improvements in generative modeling we apply a diffusion model to generate photon showers as high-cardinality point clouds. ii) These point clouds of up to $6,000$ space points are largely geometry-independent as they are down-sampled from initial even higher-resolution point clouds of up to $40,000$ so-called Geant4 steps. We showcase the performance of this approach using the specific example of simulating photon showers in the planned electromagnetic calorimeter of the International Large Detector (ILD) and achieve overall good modeling of physically relevant distributions.

    ↳ physics.ins-detcs.LGhep-exhep-ph+1JINST(2023)·94 citations
39. 39*

    A review on Glueball hunting

    Davide Vadacchino🇬🇧

    One of the most direct predictions of QCD is the existence of color-singlet states called Glueballs, which emerge as a consequence of the gluon field self-interactions. Despite the outstanding success of QCD as a theory of the strong interaction and decades of experimental and theoretical efforts, all but the most basic properties of Glueballs are still being debated. In this talk, I will review efforts aimed to understanding Glueballs and the current status of Glueball searches, including recent experimental results and lattice calculations.

    ↳ hep-lathep-exhep-ph26 citations
40. 40*

    Primordial black holes from strong first-order phase transitions

    Marek Lewicki🇵🇱 · Piotr Toczek🇵🇱 · Ville Vaskonen🇪🇪

    We study the formation of primordial black holes (PBHs) in strongly supercooled first-order phase transitions. The mechanism is based on the presence of remnants dominated by the false vacuum that scale slower with the expansion of the Universe than their surroundings where this energy was already converted into radiation. We compute the PBH formation from these remnants including the contribution from the false vacuum and the bubble walls, by estimating the collapse using the hoop conjecture and by considering both regions collapsing immediately when entering the horizon and sub-horizon regions that collapse as their compactness grows. We show that for exponential bubble nucleation rate, $\Gamma \propto e^{\beta t}$, the primordial black hole formation implies $\beta /H\gtrsim 3.8$, where $H$ denotes the Hubble rate, if the potential energy of the false vacuum is $\Delta V\lesssim (10^{12}\mathrm{GeV}{)}^4$, as otherwise a too large abundance of long-lived PBHs forms. The observed dark matter abundance can be formed in asteroid mass PBHs if $\beta /H\simeq 3.8$ and $10^5\mathrm{GeV}\lesssim \Delta V^{1/4}\lesssim 10^8\mathrm{GeV}$. Finally, we consider also the effect of the second order correction to the exponential nucleation rate showing that the PBH abundance is mainly determined by the average radius of the true vacuum bubbles.

    ↳ astro-ph.COhep-phJHEP(2023)·136 citations
41. 41*

    Suggestions of decreasing dark energy from supernova and BAO data

    Mark Van Raamsdonk🇨🇦 · Chris Waddell🇨🇦

    The potential energy from a time-dependent scalar field provides a possible explanation for the observed cosmic acceleration. In this paper, we investigate how data from supernova and bary acoustic oscillation surveys constrain the possible evolution of a single scalar field over the period of time (roughly half the age of the universe) for which these data are available. Taking a linear approximation to the scalar potential $V(\varphi )=V_0+V_1\varphi$ around the present value, a likelihood analysis appears to significantly prefer models with a decreasing potential energy at present, with approximately $99.99\%$ of the $\exp (-{\chi }^2/2)$ distribution having $V_1>0$ in a convention where $\dot{\varphi }\le 0$ at present. The models favoured by the distribution typically have an order one decrease $⟨|\mathrm{Range}[V(\varphi (t))]/V(t_0)|⟩\approx 0.36$ in the scalar potential energy over the time frame corresponding to $z<2$. According to the likelihood analysis, the $\Lambda$CDM model with no variation in dark energy appears to be significantly disfavoured in the context of the linear potential model, but this should be interpreted cautiously since model selection criteria that make use of $\Delta {\chi }^2$ while ignoring parameter space volumes still favour $\Lambda$CDM. Working with a second order approximation to the potential, the supernova data can be fit well for a wide range of possible potentials, including models where the universe has already stopped accelerating.

    ↳ astro-ph.COhep-phhep-thJCAP(2024)·35 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.