Fri·Aug 4, 2023Friday·August 4, 2023

1. 01*

   Lessons from LHC on the LFV Higgs decays $h\to {\ell }_a{\ell }_b$ in the Two-Higgs Doublet Models

   M. A. Arroyo-Ureña🇲🇽 · J. Lorenzo Díaz-Cruz🇲🇽 · O. Félix-Beltrán🇲🇽 · M. Zeleny-Mora🇲🇽

   The non-conservation of the lepton number has been explored at the LHC through the Lepton-Flavor Violating (LFV) Higgs decays $h\to {\ell }_a{\ell }_b$, with ${\ell }_{a,b}=e,\mu ,\tau$ $(a\ne b)$. Current limits on these decays are a source of valuable information on the structure of the Yukawa and Higgs sectors. The LFV Higgs couplings can arise within the general Two-Higgs Doublet Model (2HDM); the predicted rates for these decay modes depend on the specific Yukawa structure being considered, ranging from a vanishing branching ratio at tree-level for some versions (2HDM-I, II, X, Y), up to large and detectable ratios within the general 2HDM-III. An attractive scenario is given by the texturized version of the model (2HDM-Tx), with the Yukawa matrices having some texture zeros, such as the minimal version with the so-called Cheng-Sher ansazt. We study the constraints on the parameter space of the 2HDM provided by experimental and theoretical restrictions, and use them to study the detection of LFV Higgs modes at LHC. We find several encouraging scenarios to the search for the decay $h\to \tau \mu$ that could be achieved in the High-Luminosity LHC. On the other hand, LFV Higgs couplings can also be induced at one-loop level in the 2HDM with neutrino masses, with the loops being mediated by neutrino interactions; we find that the resulting branching ratios are of order $10^{-7}$ at best, which is out of the reach of current and future phases of the LHC.

   hep-phInt.J.Mod.Phys.A(2024)·7 citations
2. 02*

   Single inclusive particle production in pA collisions at forward rapidities: beyond the hybrid model

   Tolga Altinoluk🇵🇱 · Néstor Armesto🇪🇸 · Alexander Kovner🇺🇸 · Michael Lublinsky🇮🇱

   In this contribution we reconsider the calculation at next-to-leading order of forward inclusive single hadron production in $pA$ collisions within the hybrid approach. We conclude that the proper framework to compute this cross section beyond leading order is not collinear factorization as assumed so far, but the TMD factorized framework.

   hep-phnucl-th0 citations
3. 03*

   Second resonance of the Higgs field: motivations, experimental signals, unitarity constraints

   Maurizio Consoli🇮🇹 · George Rupp🇵🇹

   Perturbative calculations predict that the Standard Model (SM) effective potential should have a new minimum, well beyond the Planck scale, much deeper than the electroweak vacuum. As it is not obvious that gravitational effects can get so strong to stabilize the potential, most authors have accepted the metastability scenario in a cosmological perspective. This perspective is needed to explain why the theory remains trapped into our electroweak vacuum, but requires to control the properties of matter in the extreme conditions of the early universe. Alternatively, one can consider the completely different idea of a non-perturbative effective potential which, as at the beginning of the SM, is restricted to the pure ${\Phi }^4$ sector yet consistent with the now existing analytical and numerical studies. In this approach, where the electroweak vacuum is the lowest-energy state, besides the resonance of mass $m_h=125$ GeV defined by the quadratic shape of the potential at its minimum, the Higgs field should exhibit a second resonance with mass $690\pm 10(\mathrm{stat})\pm 20(\mathrm{sys})$ GeV associated with the zero-point energy determining the potential depth. Despite its large mass, this would couple to longitudinal $W$s with the same typical strength as the low-mass state at 125 GeV and represent a relatively narrow resonance of width ${\Gamma }_H=30÷38$ GeV, mainly produced at LHC by gluon-gluon fusion. So it is interesting that, in the LHC data, one can find various indications for a new resonance in the expected mass range with a non-negligible statistical significance. As this could become an important new discovery by just adding two missing samples of RUN2 data, we outline further refinements of the theoretical predictions that could be obtained by implementing unitarity constraints, in the presence of fermion and gauge fields, with coupled-channel calculations used for meson spectroscopy.

   hep-phhep-exEPJC(2024)·6 citations
4. 04*

   Production cross-sections and Radiative Decay widths of Heavy Quarkonia in magnetized matter

   Amruta Mishra🇮🇳 · Ankit Kumar🇮🇳 · S.P. Misra🇮🇳

   We study the production cross-sections and radiative decay widths of heavy quarkonia (charmonia and bottomonia) in magnetized nuclear matter. The production cross-sections of the $\psi (3770)$ and ${\rm Y}(4S)$, from the $D\bar{D}$ and $B\bar{B}$ scatterings respectively, are studied from the medium modifications of the masses and partial decay widths to open charm (bottom) mesons, of these heavy flavor mesons. Within a chiral effective model, the masses of the vector and pseudoscalar charmonium (bottomonium) states are calculated from the medium modification of a dilaton field, $\chi$, which mimics the gluon condensates of QCD. In the presence of a magnetic field, there is mixing of the pseudoscalar (P) meson and the longitudinal component of the vector (V) meson (PV mixing), which leads to appreciable modifications of their masses. The radiative decay widths of the vector (V) heavy quarkonia to the pseudoscalar (P) mesons ($J/\psi \to {\eta }_c(1S)\gamma$, $\psi (2S)\to {\eta }_c(2S)\gamma$ and $\psi (1D)\to {\eta }_c(2S)\gamma$ for the charm sector and ${\rm Y}(NS)\to {\eta }_b(NS)\gamma$, $N$=1,2,3,4, for the bottom sector) in the magnetized asymmetric nuclear matter are also investigated in the present work. The difference in the mass of the transverse component from the longitudinal component of the vector meson, arising due to PV mixing, is observed as a double peak structure in the invariant mass spectrum of the production cross-section of $\psi (3770)$. The modifications of the production cross-sections as well as the radiative decay widths of the heavy quarkonia in the magnetized matter should have observable consequences on the production of these heavy flavour mesons resulting from ultra-relativistic peripheral heavy ion collision experiments, where the created magnetic field can be extremely large.

   hep-phIJMPE(2023)·2 citations
5. 05*

   Longer-Lived Mediators from Charged Mesons and Photons at Neutrino Experiments

   Bhaskar Dutta🇺🇸 · Aparajitha Karthikeyan🇺🇸 · Doojin Kim🇺🇸

   Since many of the dark-sector particles interact with Standard Model (SM) particles in multiple ways, they can appear in experimental facilities where SM particles appear in abundance. In this study, we explore a particular class of longer-lived mediators that are produced from photons, charged mesons, neutral mesons, and $e^{\pm }$ that arise in proton-beam fixed-target-type neutrino experiments. This class of mediators encompasses light scalars that appear in theories like extended Higgs sectors, muon(electro)philic scalars, etc. We evaluate the sensitivities of these mediators at beam-based neutrino experiments such as the finished ArgoNeuT, ongoing MicroBooNE, SBND, ICARUS, and the upcoming DUNE experiment. We realize that scalars are more enhanced while produced from three-body decay of charged mesons, especially if they are muonphilic in nature. For scenarios that contain muonphilic scalars, these experiments can probe unexplored regions of parameter space that can explain the current discrepancy in the anomalous magnetic moment of muons. The sensitivity of electrophilic scalars at the DUNE Near Detector can explore new regions. We also show that Bethe-Heitler scattering processes can be used to probe flavor-specific lepton final states even for the mediator masses below twice the lepton mass.

   hep-phhep-exPRD(2024)·8 citations
6. 06*

   Light-by-light scattering in ultraperipheral collisions of heavy ions with future FoCal and ALICE 3 detectors

   P. Jucha🇵🇱 · M. Klusek-Gawenda🇵🇱 · A. Szczurek🇵🇱

   We discuss possible future studies of photon-photon (light-by-light) scattering using a planned FoCal and ALICE 3 detectors. We include different mechanisms of $\gamma \gamma \to \gamma \gamma$ scattering, such as double-hadronic photon fluctuations, $t/u$-channel neutral pion exchange or resonance excitations ($\gamma \gamma \to R$) and deexcitation ($R\to \gamma \gamma$). The broad range of (pseudo)rapidities and lower cuts on transverse momenta open a necessity to consider not only dominant box contributions but also other subleading contributions. Here we include low mass resonant $R={\pi }^0$, $\eta$, ${\eta }^{\prime }$ contributions. The resonance contributions give intermediate photon transverse momenta. However, these contributions can be eliminated by imposing windows on di-photon invariant mass. We study and quantify individual box contributions (leptonic, quarkish). The electron/positron boxes dominate at low $M_{\gamma \gamma }<1$ GeV di-photon invariant masses. The PbPb$\to$PbPb$\gamma \gamma$ cross section is calculated within equivalent photon approximation in the impact parameter space. Several differential distributions are presented and discussed. We consider four different kinematic regions. We predict cross section in the (mb-b) range for typical ALICE 3 cuts, a few orders of magnitude larger than for the current ATLAS or CMS experiments. We also consider the two-${\pi }^0$ background which can, in principle, be eliminated at the new kinematical range for the ALICE 3 measurements by imposing dedicated cuts on di-photon transverse momentum and\or so-called vector asymmetry.

   hep-phPRD(2024)·15 citations
7. 07*

   New Constraint on Dark Photon at T2K Off-Axis Near Detector

   Takeshi Araki🇯🇵 · Kento Asai🇯🇵 · Tomoya Iizawa🇯🇵 · Hidetoshi Otono🇯🇵 · Takashi Shimomura🇯🇵 · Yosuke Takubo🇯🇵

   The T2K experiment is one of the most powerful long-baseline experiments to investigate neutrino oscillations. The off-axis near detector called ND280 is installed 280 m downstream from the neutrino production target to measure the neutrino energy spectrum. In this paper, we study the capability of the ND280 detector to search for the dark photon produced through the meson rare decay and proton bremsstrahlung processes at the proton beam dump. We find that the ten-year operation of T2K with the ND280 detector excludes the unexplored parameter region for the dark photon mass and kinetic mixing. We also show that a broader parameter region can be searched by the ND280 in the future T2K operation for dark photon as well as U(1)${}_{B-L}$ gauge boson.

   hep-phhep-exJHEP(2023)·11 citations
8. 08*

   Spectral properties of $\omega$, $\rho$ and $A_1$ mesons in hot magnetized matter: effects of (inverse) magnetic catalysis

   Pallabi Parui🇮🇳 · Amruta Mishra🇮🇳

   In-medium masses of the light vector $\omega$, $\rho$ and axial-vector $A_1$ mesons are studied in the magnetized hot nuclear matter, accounting for the effects of (inverse) magnetic catalysis. The in-medium partial decay widths for the $A_1\to \rho \pi$ channels are studied from the in-medium masses of the initial and the final state particles, by applying a phenomenological Lagrangian to account for the $A_1\rho \pi$ interaction vertices. The masses are calculated within the QCD sum rule framework, with the medium effects coming through the light quark ($\sim ⟨\bar{q}q⟩$) and the scalar gluon condensates ($\sim ⟨G^2⟩$), as well as the light four-quark condensate ($\sim ⟨\bar{q}q{⟩}^2$). The condensates are calculated within the chiral $SU(3)$ model in terms of the medium modified scalar fields: isoscalar $\sigma$, $\zeta$, isovector $\delta$ and the dilaton field $\chi$. The effects of magnetic fields are incorporated through the magnetized Dirac sea contribution as well as the Landau energy levels of protons. The incorporation of the magnetic field through the Dirac sea of nucleons lead to an enhancement (reduction) of the light quark condensates with magnetic field, give rise to the phenomenon of magnetic (inverse) catalysis. The effects of (inverse) magnetic catalysis at finite temperature nuclear matter are studied on the spectral functions and production cross-sections of the neutral $\rho$ and $A_1$ mesons. This may affect the production of the light vector and axial-vector mesons in the peripheral heavy-ion collision experiments, where estimated magnetic field is very large at the early stages of collisions with very high temperature.

   hep-phPRD(2023)·6 citations
9. 09*

   Momentum spectrum of Schwinger pair production in four-dimensional e-dipole fields

   Gianluca Degli Esposti🇩🇪 · Greger Torgrimsson🇸🇪

   We calculate the momentum spectrum of electron-positron pairs created via the Schwinger mechanism by a class of four-dimensional electromagnetic fields called e-dipole fields. To the best of our knowledge, this is the first time the momentum spectrum has been calculated for 4D, exact solutions to Maxwell's equations. Moreover, these solutions give fields that are optimally focused, and are hence particularly relevant for future experiments. To achieve this we have developed a worldline instanton formalism where we separate the process into a formation and an acceleration region.

   hep-phhep-thPRD(2024)·15 citations
10. 10*

    Conversion of protons to positrons by a black hole

    A.D. Dolgov🇷🇺 · A.S. Rudenko🇷🇺

    The conversion of protons to positrons at the horizon of a black hole (BH) is considered. It is shown that the process may efficiently proceed for BHs with masses in the range $\sim 10^{18}$ -- $10^{21}$ g. It is argued that the electric charge of BH acquired by the proton accretion to BH could create electric field near BH horizon close to the critical Schwinger one. It leads to efficient electron-positron pair production, when electrons are back captured by the BH while positrons are emitted into outer space. Annihilation of these positrons with electrons in the interstellar medium may at least partially explain the origin of the observed 511 keV line.

    hep-phgr-qcPhys.Part.Nucl.Lett.(2024)·6 citations
11. 11*

    Multi-photon signatures as a probe of CP-violation in extended Higgs sectors

    Shinya Kanemura🇯🇵 · Kento Katayama🇯🇵 · Tanmoy Mondal🇯🇵 · Kei Yagyu🇯🇵

    We propose a novel signature with four-photon final states to probe CP-violating (CPV) extended Higgs sectors via $f\bar{f}\to Z^{\ast }\to H_1{H}_2\to 4\gamma$ processes with $H_{1,2}$ being additional neutral Higgs bosons. We focus on the nearly Higgs alignment scenario, in which the discovered Higgs boson almost corresponds to a neutral scalar state belonging to the isospin doublet field with the vacuum expectation value $v\simeq 246$ GeV. We show that the branching ratios of $H_{1,2}\to \gamma \gamma$ can simultaneously be sizable when CPV phases in the Higgs potential are of order one due to the enhancement of charged-Higgs boson loops. Such branching ratios can be especially significant when the fermiophobic scenario is taken into account. As a simple example, we consider the general two Higgs doublet model, and demonstrate that the cross section for the four-photon process can be 0.1 fb at LHC with the masses of $H_{1,2}$ to be a few 100 GeV in the Higgs alignment limit under the constraints from electric dipole moments (EDMs) and LHC Run-II data. We also illustrate that the searches for EDMs and di-photon resonances at high-luminosity LHC play complementary roles to explore CPV extended Higgs sectors.

    hep-phhep-exPRD(2024)·2 citations
12. 12*

    Resonant Pseudo-Dirac Dark Matter as a Sub-GeV Thermal Target

    Nirmalya Brahma🇨🇦 · Saniya Heeba🇨🇦 · Katelin Schutz🇨🇦

    Dark matter (DM) could be a pseudo-Dirac thermal relic with a small mass splitting that is coupled off-diagonally to a kinetically mixed dark photon. This model, particularly in the sub-GeV mass range, is a key benchmark for accelerator searches and direct detection experiments. Typically, the presence of even a tiny fraction of pseudo-Dirac DM in the excited state around the time of recombination would be excluded by DM annihilation bounds from the cosmic microwave background (CMB); thus, viable thermal histories must typically feature an exponential suppression of the excited state. We revisit assumptions about the thermal history in the resonant regime, where the dark photon mass is slightly more than twice the DM mass (to within $\sim 10\%$), leading to an $s$-channel resonance in the annihilation cross section. This resonance substantially reduces the couplings required for achieving the observed relic abundance, implying that in much of the parameter space, the DM kinetically decouples from the Standard Model well before the final DM relic abundance is achieved. We find that the excited state is not thermally depopulated in this regime. In spite of this, we find that the presence of the excited state does $\text{not}$ violate CMB bounds, even for arbitrarily small mass splittings. The present-day abundance of the excited state opens up the possibility of signatures that are usually not relevant for pseudo-Dirac DM, including indirect detection, direct detection, and self-interacting DM signatures.

    hep-phastro-ph.COPRD(2024)·35 citations
13. 13*

    Creating kinks with quantum mediation

    Omer Albayrak🇺🇸 · Tanmay Vachaspati🇺🇸

    We consider the creation of kink-antikink pairs of a scalar field $\varphi$ by the scattering of classical wavepackets of a second scalar field, $\psi$, when there are no direct interactions between $\varphi$ and $\psi$. The creation becomes possible only due to a quantum field that interacts with both $\varphi$ and $\psi$. We scan parameter space and find it favorable for kink production when the initial wavepackets have large total energy and wide spatial extent but scatter at low velocities.

    hep-phhep-thPRD(2024)·8 citations
14. 14*

    Supernova Simulations Confront SN 1987A Neutrinos

    Damiano F. G. Fiorillo (1)🇩🇰 · Malte Heinlein (2 and 3)🇩🇪 · Hans-Thomas Janka (2)🇩🇪 · Georg Raffelt (4)🇩🇪 · Edoardo Vitagliano (5)🇮🇱 · Robert Bollig (2) ((1) Niels Bohr Institute, (2) MPI Astrophysik, (3) TUM Garching, (4) MPI Physik, (5) Racah Institute of Physics)🇩🇪

    We return to interpreting the historical SN~1987A neutrino data from a modern perspective. To this end, we construct a suite of spherically symmetric supernova models with the Prometheus-Vertex code, using four different equations of state and five choices of final baryonic neutron-star (NS) mass in the 1.36-1.93 M${}_{\odot }$ range. Our models include muons and proto-neutron star (PNS) convection by a mixing-length approximation. The time-integrated signals of our 1.44 M${}_{\odot }$ models agree reasonably well with the combined data of the four relevant experiments, IMB, Kam-II, BUST, and LSD, but the high-threshold IMB detector alone favors a NS mass of 1.7-1.8 M${}_{\odot }$, whereas Kam-II alone prefers a mass around 1.4 M${}_{\odot }$. The cumulative energy distributions in these two detectors are well matched by models for such NS masses, and the previous tension between predicted mean neutrino energies and the combined measurements is gone, with and without flavor swap. Generally, our predicted signals do not strongly depend on assumptions about flavor mixing, because the PNS flux spectra depend only weakly on antineutrino flavor. While our models show compatibility with the events detected during the first seconds, PNS convection and nucleon correlations in the neutrino opacities lead to short PNS cooling times of 5-9 s, in conflict with the late event bunches in Kam-II and BUST after 8-9 s, which are also difficult to explain by background. Speculative interpretations include the onset of fallback of transiently ejected material onto the NS, a late phase transition in the nuclear medium, e.g., from hadronic to quark matter, or other effects that add to the standard PNS cooling emission and either stretch the signal or provide a late source of energy. More research, including systematic 3D simulations, is needed to assess these open issues.

    ↳ astro-ph.HEhep-phPRD(2023)·102 citations
15. 15*

    Search for Dark-Matter-Nucleon Interactions with a Dark Mediator in PandaX-4T

    Di Huang · Abdusalam Abdukerim · Zihao Bo · Wei Chen · Xun Chen · Yunhua Chen · Chen Cheng · Zhaokan Cheng · Xiangyi Cui · Yingjie Fan · Deqing Fang · Changbo Fu and 82 other authors

    We report results of a search for dark-matter-nucleon interactions via a dark mediator using optimized low-energy data from the PandaX-4T liquid xenon experiment. With the ionization-signal-only data and utilizing the Migdal effect, we set the most stringent limits on the cross section for dark matter masses ranging from 30~$MeV/{\mathrm{c}}^2$ to 2~$GeV/{\mathrm{c}}^2$. Under the assumption that the dark mediator is a dark photon that decays into scalar dark matter pairs in the early Universe, we rule out significant parameter space of such thermal relic dark-matter model.

    ↳ hep-exhep-phPRL(2023)·76 citations
16. 16*

    Probing Hadron-quark Transition Through Binary Neutron Star Merger

    Ling-Jun Guo🇨🇳 · Wen-Cong Yang🇨🇳 · Yong-Liang Ma🇨🇳 · Yue-Liang Wu🇨🇳

    The cores of massive neutron stars offer a unique environment for the nuclear matter at intermediate density in the universe. The global characteristics of a neutron star, as well as the gravitational waves emitted from the mergers of two neutron stars, offer valuable insights into dense nuclear matter. In this paper, we comprehensively investigate the effect of the potential hadron-quark transition on the properties of neutron stars and the signals of the gravitational waves stemming from the merger of binary neutron stars, including waveforms, frequency evolutions as well as the spectrum curves, utilizing the equations of state constructed from the Maxwell ansatz, Gibbs ansatz and, the crossover scenario. We explicitly construct the equations of state in such a way that they converge at low and high densities therefore the differences are only from the scenarios of the transitions and the locations -- or the parameters in the equation of state. Using such constructed equations of state, we simulate the signals of the gravitational wave (GW) and analyze their differences due to locations of the transition, the scenarios of the transition, and the masses of the component stars. We find that (1) in both the Maxwell ansatz and Gibbs ansatz, GW signals are sensitive to the location and the latent heat of the phase transition, (2) in the post-merger phase, the frequency of GW increases with the evolution in Maxwell type transition but is stable in the other two types of transitions and, (3) the amount of radiated energy is the biggest in Gibbs construction (GC) type transition and the smallest in the crossover construction (CC) type transition. By combining our findings with the expected detection of gravitational waves around $(2$-$4)$ kHz from binary neutron star mergers and their associated electromagnetic signals, we expect to uncover some key characteristics of dense nuclear matter.

    ↳ astro-ph.HEhep-phRes.Astron.Astrophys.(2025)·13 citations
17. 17*

    Parametrized uncertainties in the spectral function model of neutrino charged-current quasielastic interactions for oscillation analyses

    J. Chakrani🇫🇷 · S. Dolan🇨🇭 · M. Buizza Avanzini🇫🇷 · A. Ershova🇫🇷 · L. Koch🇩🇪 · K. McFarland🇺🇸 · G. D. Megias🇪🇸 · L. Munteanu🇨🇭 · L. Pickering🇬🇧 · K. Skwarczynski🇵🇱 · V. Q. Nguyen🇫🇷 · C. Wret🇬🇧

    A substantial fraction of systematic uncertainties in neutrino oscillation experiments stem from the lack of precision in modeling the nuclear target in neutrino-nucleus interactions. Whilst this has driven significant progress in the development of improved nuclear models for neutrino scattering, it is crucial that the models used in neutrino data analyses be accompanied by parameters and associated uncertainties that allow the coverage of plausible nuclear physics. Based on constraints from electron scattering data, we develop such a set of parameters, which can be applied to nuclear shell models, and test their application to the Benhar et al spectral function model. The parametrization is validated through a series of maximum likelihood fits to cross-section measurements made by the T2K and MINERvA experiments, which also permit an exploration of the power of near-detector data to provide constraints on the parameters in neutrino oscillation analyses.

    ↳ hep-exhep-phPRD(2024)·20 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.