Mon·Jun 13, 2022Monday·June 13, 2022

1. 01*

   Right-handed sneutrino and gravitino multicomponent dark matter in light of neutrino detectors

   Jong Soo Kim🇿🇦 · Daniel E. Lopez-Fogliani🇦🇷 · Andres D. Perez🇦🇷 · Roberto Ruiz de Austri🇪🇸

   We investigate the possibility that right-handed (RH) sneutrinos and gravitinos can coexist and explain the dark matter (DM) problem. We compare extensions of the minimal supersymmetric standard model (MSSM) and the next-to-MSSM (NMSSM) adding RH neutrinos superfields, with special emphasis on the latter. If the gravitino is the lightest supersymmetric particle (LSP) and the RH sneutrino the next-to-LSP (NLSP), the heavier particle decays to the former plus left-handed (LH) neutrinos through the mixing between the scalar partners of the LH and RH neutrinos. However, the interaction is suppressed by the Planck mass, and if the LH-RH sneutrino mixing parameter is small, $\ll O(10^{-2})$, a long-lived RH sneutrino NLSP is possible even surpassing the age of the Universe. As a byproduct, the NLSP to LSP decay produces monochromatic neutrinos in the ballpark of current and planned neutrino telescopes like Super-Kamiokande, IceCube and Antares that we use to set constraints and show prospects of detection. In the NMSSM+RHN, assuming a gluino mass parameter $M_3=3$ TeV we found the following lower limits for the gravitino mass $m_{3/2}\gtrsim 1-600$ GeV and the reheating temperature $T_R\gtrsim 10^5-3\times 10^7$ GeV, for $m_{{\tilde{\nu }}_R}\sim 10-800$ GeV. If we take $M_3=10$ TeV, then the limits on $T_R$ are relaxed by one order of magnitude.

   hep-phJCAP(2023)·2 citations
2. 02*

   Long lived inert Higgs in fast expanding universe and its imprint on cosmic microwave background

   Dilip Kumar Ghosh🇮🇳 · Sk Jeesun🇮🇳 · Dibyendu Nanda🇰🇷

   Presence of any extra radiation energy density at the time of cosmic microwave background formation can significantly impact the measurement of the effective relativistic neutrino degrees of freedom or $\mathrm{\Delta }{\mathrm{N}}_{\mathrm{eff}}$ which is very precisely measured by the Planck collaboration. Here, we propose a scenario where a long lived inert scalar, which is very weakly coupled to dark sector, decays to a fermion dark matter via freeze-in mechanism plus standard model neutrinos at very low temperature $(T<T_{\mathrm{BBN}})$. We explore this model in the fast expanding universe, where it is assumed that the early epoch $(T>T_{\mathrm{BBN}})$ of the universe is dominated by a non-standard species $\Phi$ instead of the standard radiation. In this non-standard cosmological picture, such late time decay of the inert scalar can inject some entropy to the neutrino sector after it decouples from the thermal bath and this will make substantial contribution to $\mathrm{\Delta }{\mathrm{N}}_{\mathrm{eff}}$. Besides, in this scenario, the new contribution to $\Delta N_{\mathrm{eff}}$ is highly correlated with the dark matter sector. Thus, one can explore such feebly interacting dark matter particles (FIMP) by the precise measurement of $\Delta N_{\mathrm{eff}}$ using the current (Planck2018) and forthcoming (CMB-S4 \& SPT3G) experiments.

   hep-phastro-ph.COPRD(2022)·20 citations
3. 03*

   Jets separated by a large pseudorapidity gap at the Tevatron and at the LHC

   C. Baldenegro🇫🇷 · P. Gonzalez Duran🇩🇪 · M. Klasen🇩🇪 · C. Royon🇺🇸 · J. Salomon🇩🇪

   We present a phenomenological analysis of events with two high transverse momentum ($p_T$) jets separated by a large (pseudo-)rapidity interval void of particle activity, also known as jet-gap-jet events. In the limit where the collision energy $\sqrt{s}$ is much larger than any other momentum scale, the jet-gap-jet process is described in terms of perturbative pomeron exchange between partons within the Balitsky--Fadin--Kuraev--Lipatov (BFKL) limit of perturbative quantum chromodynamics (QCD). The BFKL pomeron exchange amplitudes, with resummation at the next-to-leading logarithmic approximation, have been embedded in the PYTHIA8 Monte Carlo event generator. Standard QCD dijet events are simulated at next-to-leading order in ${\alpha }_s$ matched to parton showers with POWHEG+PYTHIA8. We compare our calculations to measurements by the CDF, D0, and CMS experiments at center-of-mass energies of 1.8, 7 and 13 TeV. The impact of the theoretical scales, the parton densities, final- and initial-state radiation effects, multiple parton interactions, and $p_T$ thresholds and multiplicities of the particles in the rapidity gap on the jet-gap-jet signature is studied in detail. With a strict gap definition (no particle allowed in the gap), the shapes of most distributions are well described except for the CMS azimuthal-angle distribution at 13 TeV. The survival probability is surprisingly well modelled by multiparton interactions in PYTHIA8. Without multiparton interactions, theoretical predictions based on two-channel eikonal models agree qualitatively with fits to the experimental data.

   hep-phhep-exJHEP(2022)·10 citations
4. 04*

   Axial-vector and pseudoscalar tetraquarks $[ud][\bar{c}\bar{s}]$

   H. Sundu🇹🇷 · S. S. Agaev🇦🇿 · K. Azizi🇮🇷

   Spectroscopic parameters and widths of the fully open-flavor axial-vector and pseudoscalar tetraquarks $X_{\mathrm{AV}}$ and $X_{\mathrm{PS}}$ with content $[ud][\overline{c}\overline{s}]$ are calculated by means of the QCD sum rule methods. Masses and current couplings of $X_{\mathrm{AV}}$ and $X_{\mathrm{PS}}$ are found using two-point sum rule computations performed by taking into account various vacuum condensates up to dimension $10$. The full width of the axial-vector state $X_{\mathrm{AV}}$ is evaluated by including into analysis $S$-wave decay modes $X_{\mathrm{AV}}\to D^{\ast }(2010{)}^{-}{K}^{+}$, ${\overline{D}}^{\ast }(2007{)}^0{K}^0$, $D^{-}{K}^{\ast }(892{)}^{+}$, and ${\overline{D}}^0{K}^{\ast }(892{)}^0$. In the case of $X_{\mathrm{PS}}$, we consider $S$-wave decay $X_{\mathrm{PS}}\to {\overline{D}}_0^{\ast }(2300{)}^0{K}^0$, and $P$-wave processes $X_{\mathrm{PS}}\to D^{-}{K}^{\ast }(892{)}^{+}$ and $X_{\mathrm{PS}}\to {\overline{D}}^0{K}^{\ast }(892{)}^0$. To determine partial widths of these decay modes, we employ the QCD light-cone sum rule method and soft-meson approximation, which are necessary to estimate strong couplings at tetraquark-meson-meson vertices $X_{\mathrm{AV}}{D}^{-}{D}^{\ast }(2010{)}^{-}{K}^{+}$, etc. Our predictions for the mass $m_{\mathrm{AV}}=(2800\pm 75)\mathrm{MeV}$ and width ${\Gamma }_{\mathrm{AV}}=(58\pm 10)\mathrm{MeV}$ of the tetraquark $X_{\mathrm{AV}}$, as well as results $m_{\mathrm{PS}}=(3000\pm 60)\mathrm{MeV}$ and ${\Gamma }_{\mathrm{PS}}=(65\pm 12)\mathrm{MeV}$ for the same parameters of $X_{\mathrm{PS}}$ may be useful in future experimental studies of multiquark hadrons.

   hep-phhep-exhep-latEPJC(2023)·6 citations
5. 05*

   Constraints on Light Leptophilic Dark Matter Mediators from Decay Experiments

   Gerrit Bickendorf🇩🇪 · Manuel Drees🇩🇪

   We study the influence of leptophilic dark matter interactions on decays of muons and ground state mesons in existing experiments. We consider a secluded dark sector exclusively interacting with leptons via either a (leptophilic) scalar or vector mediator. These interactions will therefore influence leptonic decays and deform the energy spectra. We first study the Michel decay of muons, ${\mu }^{+}\to e^{+}{\nu }_e{\bar{\nu }}_{\mu }$, which allow us to constrain the parameter space reasonably well. Secondly, the rare ${\pi }^{\pm }$, $K^{\pm }$, $D^{\pm }$ and $D_s^{\pm }$ decays to $e\nu$ will be considered. Scalar mediators would remove the Standard Model helicity suppression, so that strong constraints can be derived. The resulting bounds on the couplings of the light mediators to electrons and muons still turn out to be somewhat weaker than those from searches at low--energy $e^{+}{e}^{-}$ colliders and the magnetic moment of the muon, respectively. Finally, we show that kaon and pion decays basically exclude a ''Co--SIMP'' scenario where a scalar dark matter particle has a dimension--5 coupling to electrons.

   hep-phEPJC(2022)·16 citations
6. 06*

   Improved cosmological bounds for a fine-tuned see-saw mechanism of keV sterile neutrinos

   M. N. Dubinin🇷🇺 · D. M. Kazarkin🇷🇺

   Considering the gauge model SU(2)_L x U(1) with the extension of the lepton sector by right-handed sterile Majorana neutrinos, we distinguish a "minimal parametric mixing scenario" for a complete matrix of 6 x 6 light (active) and sterile neutrinos, which depends, in addition to experimentally measured physical parameters, only on the masses of sterile neutrinos. For such a scenario, improved cosmological bounds are provided, resulting from the lifetime of sterile neutrinos and the fraction of energy carried by sterile neutrino dark matter.

   hep-phastro-ph.CO2 citations
7. 07*

   Magnetic moments of the vector hidden-charmed tetraquark states

   U. Ozdem🇹🇷

   The magnetic moments of the vector hidden-charmed tetraquark states that have been observed and can be expected to be observed experimentally have been determined using the light-cone sum rules taking into account the diquark-antidiquark structure with the quantum numbers $J^{PC}=1^{--}$ and $J^{PC}=1^{-+}$. Since these states are considered to have different flavors of light quarks, they have nonzero magnetic moments. The results obtained in this study can be checked for consistency by various methods. The magnetic moments of hadrons encompass useful knowledge about the distribution of charge and magnetization inside hadrons, which helps us to understand their geometrical shapes.

   hep-phhep-exhep-latPRD(2022)·8 citations
8. 08*

   Anomalies, CPT and Leptogenesis

   Sarben Sarkar🇬🇧

   We bring together different puzzles in physics beyond the Standard Model of particle physics. Within our model baryogenesis, neutrino mass, strong CP and dark matter puzzles are related. The common ingredient in connecting these puzzles is the Kalb-Ramond field, a two form present in the gravitational multiplet in the theory of closed strings. Leptons are fermions which we need to couple to gravitational degrees of freedom using a vierbein formalism. The presence of torsion provided by a Kalb-Ramond background leads us to firstly an effective model involving the Einstein-Cartan formulation of gravity, a gauge theory, in which coupling to fermions is via a covariant derivative and secondly to a mechanism for CPT violation. This picture emerges from a low energy string effective action obtained from a closed bosonic string theory after compactification to four dimensions. The Kalb-Ramond field in four dimensions can be identified with a pseudoscalar gravitational axion. Because of the presence of an axial anomaly this axion can couple with the gluon field, and in this way allows a connection with the strong CP problem and axionic dark matter.

   hep-phPoS(2022)·4 citations
9. 09*

   Proton hot spots and exclusive vector meson production

   S. Demirci🇫🇮 · T. Lappi🇫🇮 · S. Schlichting🇩🇪

   We explore consequences of the existence of gluonic hot spots inside the proton for coherent and incoherent exclusive vector meson production cross sections in deep inelastic scattering. By working in the dilute limit of the Color Glass Condensate framework to compute the cross sections for Gaussian hot spots of fluctuating color charges and employing a non-relativistic vector meson wave function, we are able to perform large parts of the calculation analytically. We find that the coherent cross section is sensitive to both the size of the target and the structure of the probe. The incoherent cross section is dominated by color fluctuations at small transverse momentum transfer ($t$), by proton and hot spot sizes as well as the structure of the probe at medium $t$ and again by color fluctuations at large $t$. While the $t$-dependence of the cross section is well reproduced in our model, the relative normalization between the coherent and the incoherent cross sections points to the need for additional fluctuations in the proton.

   hep-phPRD(2022)·32 citations
10. 10*

    The vertex corrections due to the triangle singularity mechanism in the light axial vector meson couplings to $K^{\ast }\bar{K}+c.c.$

    Mengchuan Du🇨🇳 · Yin Cheng🇨🇳 · Qiang Zhao🇨🇳

    The light axial vector mesons can couple to $K^{\ast }\bar{K}+c.c.$ in an $S$ wave at the tree level. Due to the near-threshold $S$-wave interactions the couplings can be affected by the final state interactions. It is of peculiar interest that the pion exchange between $K^{\ast }\bar{K}+c.c.$ can go through a triangle diagram which is within the kinematics of the triangle singularity (TS). This mechanism will introduce energy dependence and a $D$-wave amplitude to the vertex couplings. Hence, it should be necessary to investigate the role played by the $K^{\ast }\bar{K}+c.c.$ threshold in order to have a better understanding of the light axial vector spectrum.

    hep-phPRD(2022)·13 citations
11. 11*

    The scalar garlands in the boson star

    G.A. Kozlov🇷🇺

    In the paper, we introduce the formalism to examine the impact of the hidden scalar sector to the conformal and the electroweak symmetries breaking. The novel approach to the scalar boson star (BS) naturalness is considered. The BS is presented by the local scalar field containing the Higgs boson field and the garland-like scalar dilaton fields of the conformal field theory. We show that taking into account the repulsive self-interactions and the flatness degree in the dark scalar sector prevents instability of the BS related to the black hole formation. We study in details how electroweak symmetry breaking affects the hidden sector by breaking its conformal symmetry and generating a mass gap to avoid the infra-red divergence. We apply our formalism to determine the modification of the Higgs quartic coupling away from its standard model (SM) value within the influence of the hidden sector. We have estimated the rate of the deviation from the SM with production of leptonic pairs due to decay of the dilaton and the dark photon. The latter is the subject of the dilaton decay first. The effect of new physics should be visible at the maximal energies of the LHC and the FCC.

    hep-ph0 citations
12. 12*

    Dark photon searches via Higgs boson production at the LHC and beyond

    Sanjoy Biswas🇮🇳 · Emidio Gabrielli🇮🇹 · Barbara Mele🇮🇹

    Many scenarios beyond the standard model, aiming to solve long-standing cosmological and particle physics problems, suggest that dark matter might experience long-distance interactions mediated by an unbroken dark $U(1)$ gauge symmetry, hence foreseeing the existence of a massless dark photon. Contrary to the massive dark photon, a massless dark photon can only couple to the standard model sector by means of effective higher dimensional operators. Massless dark-photon production at colliders will then in general be suppressed at low energy by a UV energy scale, which is of the order of the masses of portal (messenger) fields connecting the dark and the observable sectors. A violation of this expectation is provided by dark-photon production mediated by the Higgs boson, thanks to the non-decoupling Higgs properties. Higgs-boson production at colliders, followed by the Higgs decay into a photon and a dark photon, provides then a very promising production mechanism for the dark photon discovery, being insensitive in particular regimes to the UV scale of the new physics. This decay channel gives rise to a peculiar signature characterized by a monochromatic photon with energy half the Higgs mass (in the Higgs rest frame) plus missing energy. We show how such resonant photon-plus-missing-energy signature can uniquely be connected to a dark photon production. Higgs boson production and decay into a photon and a dark photon as a source of dark photons is reviewed at the Large Hadron Collider, in the light of the present bounds on the corresponding signature by the CMS and ATLAS collaborations. Perspectives for the dark-photon production in Higgs-mediated processes at future $e^{+}{e}^{-}$ colliders are also discussed.

    hep-phastro-ph.HEhep-exSymmetry(2022)·14 citations
13. 13*

    The viability of ultralight bosonic dark matter in dwarf galaxies

    Isabelle S. Goldstein (Brown U.)🇺🇸 · Savvas M. Koushiappas (Brown U.)🇺🇸 · Matthew G. Walker (CMU)🇺🇸

    The dark matter distribution in dwarf galaxies holds a wealth of information on the fundamental properties and interactions of the dark matter particle. In this paper, we study whether ultralight bosonic dark matter is consistent with the gravitational potential extracted from stellar kinematics. We use velocity dispersion measurements to constrain models for halo mass and particle mass. The posterior likelihood is multimodal. Particle masses of order $m\sim 10^{-22}\mathrm{eV}$ require halos of mass in excess of $\sim 10^{10}{M}_{\odot }$, while particle mass of order $m\gtrsim 10^{-20}\mathrm{eV}$ are favored by halos of mass $\sim [10^8-10^9]M_{\odot }$, with a similar behavior to cold dark matter. Regardless of particle mass, the lower halo masses are allowed if stellar dynamics are influenced by the presence of a central black hole of mass at most $\sim 10^{-2}$ the host halo mass. We find no preference for models that contain a black hole over models that do not contain a black hole. Our main conclusion is that either the fuzzy dark matter particle mass must be $m\gtrsim 10^{-20}$ eV, or the Milky Way dwarfs must be unusually heavy given the expected hierarchical assembly of the Milky Way, or the Milky Way dwarfs must contain a central black hole. We find no evidence for either of the last two possibilities and consider them unlikely.

    ↳ astro-ph.GAhep-phPRD(2022)·22 citations
14. 14*

    Deep learning techniques for Imaging Air Cherenkov Telescopes

    Songshaptak De🇮🇳 · Writasree Maitra🇮🇳 · Vikram Rentala🇮🇳 · Arun M. Thalapillil🇮🇳

    Very High Energy (VHE) gamma rays and charged cosmic rays (CCRs) provide an observational window into the acceleration mechanisms of extreme astrophysical environments. One of the major challenges at Imaging Air Cherenkov Telescopes (IACTs) designed to look for VHE gamma rays, is the separation of air showers initiated by CCRs which form a background to gamma ray searches. Two other less well studied problems at IACTs are a) the classification of different primary nuclei among the CCR events and b) identification of anomalous events initiated by Beyond Standard Model particles that could give rise to shower signatures which differ from the standard images of either gamma rays or CCR showers. The problems of categorizing the primary particle that initiates a shower image, or the problem of tagging anomalous shower events in a model independent way, are problems that are well suited to a machine learning (ML) approach. Traditional studies that have explored gamma ray/CCR separation have used a multivariate analysis based on derived shower properties, which contains significantly reduced information about the shower. In our work, we address the problems outlined above by using ML architectures trained on full simulated shower images, as opposed to training on just a few derived shower properties. We illustrate the techniques of binary and multi-category classification using convolutional neural networks, and we also pioneer the use of autoencoders for anomaly detection at VHE gamma ray experiments. As a case study, we apply our techniques to the H.E.S.S. experiment. However, the real strength of the techniques that we broach here in the context of VHE gamma ray observatories, is that these methods can be applied broadly to any other IACT, such as the upcoming Cherenkov Telescope Array (CTA), or can even be suitably adapted to CCR experiments.

    ↳ astro-ph.IMastro-ph.HEhep-phPRD(2023)·13 citations
15. 15*

    Using Neutrino Oscillations to Measure $H_0$?

    Luis A. Anchordoqui🇺🇸

    Recently, the idea of using neutrino oscillations to measure the Hubble constant was introduced. We show that such a task is unfeasible because for typical energies of cosmic neutrinos, oscillations average out over cosmological distances and so the oscillation probability depends only on the mixing angles.

    ↳ astro-ph.COhep-phUniverse(2022)·0 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.