De Romeri, V., Majumdar, A., Papoulias, D. K., & Srivastava, R. (2024). XENONnT and LUX-ZEPLIN constraints on DSNB-boosted dark matter. J. Cosmol. Astropart. Phys., 03(3), 028–34pp.
Abstract: We consider a scenario in which dark matter particles are accelerated to semirelativistic velocities through their scattering with the Diffuse Supernova Neutrino Background. Such a subdominant, but more energetic dark matter component can be then detected via its scattering on the electrons and nucleons inside direct detection experiments. This opens up the possibility to probe the sub -GeV mass range, a region of parameter space that is usually not accessible at such facilities. We analyze current data from the XENONnT and LUX-ZEPLIN experiments and we obtain novel constraints on the scattering cross sections of sub -GeV boosted dark matter with both nucleons and electrons. We also highlight the importance of carefully taking into account Earth's attenuation effects as well as the finite nuclear size into the analysis. By comparing our results to other existing constraints, we show that these effects lead to improved and more robust constraints.
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Botella, F. J., Cornet-Gomez, F., Miro, C., & Nebot, M. (2024). New physics hints from τ scalar interactions and (g-2)e,μ. J. Phys. G, 51(2), 025001–20pp.
Abstract: We consider a flavour conserving two Higgs doublet model that consists of a type I (or X) quark sector and a generalized lepton sector where the Yukawa couplings of the charged leptons to the new scalars are not proportional to the lepton masses. The model, previously proposed to solve both muon and electron g – 2 anomalies simultaneously, is also capable to accommodate the ATLAS excess in pp -> S -> tau(+)tau(-) with gluon-gluon fusion production in the invariant mass range [0.2; 0.6] TeV, including all relevant low and high energy constraints. The excess is reproduced taking into account the new contributions from the scalar H, the pseudoscalar A, or both. In particular, detailed numerical analyses favoured the solution with a significant hierarchy among the vevs of the two Higgs doublets, t(beta)similar to 10, and light neutral scalars satisfying m(A) > m(H) with sizable couplings to tau leptons. In this region of the parameter space, the muon g – 2 anomaly receives one and two-loop (Barr Zee) contributions of similar size, while the electron anomaly is explained at two loops. An analogous ATLAS excess in b-associated production and the CMS excess in ditop production are also studied. Further New Physics prospects concerning the anomalous magnetic moment of the tau lepton and the implications of the CDF M-W measurement on the final results are discussed.
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Penalva, N., Flynn, J. M., Hernandez, E., & Nieves, J. (2024). Study of new physics effects in (B)over-bars → Ds(*) τ-(ν)over-bar τ semileptonic decays using lattice QCD form factors and heavy quark effective theory. J. High Energy Phys., 01(1), 163–33pp.
Abstract: We benefit from the lattice QCD determination by the HPQCD of the Standard Model (SM) form factors for the (B) over bar (s) -> D-s [Phys. Rev. D101(2020) 074513] and the SM and tensor ones for the (B) over bar (s) -> D-s* (arXiv:2304.03137[hep-lat]) semileptonic decays, and the heavy quark effective theory (HQET) relations for the analogous B -> D-(*()) decays obtained by F.U. Bernlochner et al. in Phys. Rev. D95(2017) 115008, to extract the leading and sub-leading Isgur-Wise functions for the (B) over bar (s) -> D-s(()*()) decays. Further use of the HQET relations allows us to evaluate the corresponding scalar, pseudoscalar and tensor form factors needed for a phenomenological study of new physics (NP) effects on the (B) over bar (s) -> D-s(()*()) semileptonic decay. At present, the experimental values for the ratios R-D(*) = Gamma[ (B) over bar -> D-(*())(tau- (nu) over bar tau)]/Gamma[(B) over bar -> D-(*())e(-)(mu(-)) (nu) over bar (e(mu))]are the best signal in favor of lepton flavor universality violation (LFUV) seen in charged current (CC) b -> c decays. In this work we conduct a study of NP effects on the (B) over bar (s) -> D-s(()*()) tau(-)(tau) semileptonic decays by comparing tau spin, angular and spin-angular asymmetry distributions obtained within the SM and three different NP scenarios. As expected from SU(3) light-flavor symmetry, we get results close to the ones found in a similar analysis of the (B) over bar -> D-(*()) case. The measurement of the (B) over bar (s) -> D-s(()*())(l (nu) over bar tau) semileptonic decays, which is within reach of present experiments, could then be of relevance in helping to establish or rule out LFUV in CC b -> c transitions.
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Roca, L., Song, J., & Oset, E. (2024). Molecular pentaquarks with hidden charm and double strangeness. Phys. Rev. D, 109(9), 094005–8pp.
Abstract: We analyze theoretically the coupled-channel meson-baryon interaction with global flavor c<overline>cssn and c<overline>csss, where mesons are pseudoscalars or vectors, and baryons have JP = 1/2+ or 3/2+. The aim is to explore whether the nonlinear dynamics inherent in the unitarization process within coupled channels can dynamically generate double- and triple-strange pentaquark-type states (Pcss and Pcsss, respectively), for which there is no experimental evidence to date. We evaluate the s-wave scattering matrix by implementing unitarity in coupled channels, using potential kernels obtained from t-channel vector meson exchange. The required PPV and VVV vertices are obtained from Lagrangians derived through appropriate extensions of the local hidden gauge symmetry approach to the charm sector, while capitalizing on the symmetry of the spin and flavor wave function to evaluate the BBV vertex. We find four different poles in the double strange sector, some of them degenerate in spin. For the triple-strange channel, we find the meson-baryon interaction insufficient to generate a bound or resonance state through the unitary coupled-channel dynamics.
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Montesinos, V., Albaladejo, M., Nieves, J., & Tolos, L. (2024). Charge-conjugation asymmetry and molecular content: The Ds0*(2317)± in matter. Phys. Lett. B, 853, 138656–10pp.
Abstract: We analyze the modifications that a dense nuclear medium induces in the D-s0*(2317)(+/-) and D-s1(2460)(+/-). In the vacuum, we consider them as isoscalar D-(*K-) and (D) over bar (()*())(K) over bar S-wave bound states, which are dynamically generated from effective interactions that lead to different Weinberg compositeness scenarios. Matter effects are incorporated through the two-meson loop functions, taking into account the self energies that the D-(*()), (D) over bar (()*()), K, and (K) over bar develop when embedded in a nuclear medium. Although particle-antiparticle [D-s0,s1(()*())(2317,2460)(+) versus D-s0,s1(()*())(2317,2460)(-)] lineshapes are the same in vacuum, we find extremely different density patterns in matter. This charge-conjugation asymmetry mainly stems from the very different kaon and antikaon interaction with the nucleons of the dense medium. We show that the in-medium lineshapes found for these resonances strongly depend on their D-(*()), K/(D) over bar (()*()), K molecular content, and discuss how this novel feature can be used to better determine/constrain the inner structure of these exotic states.
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Bhattacharya, S., Mondal, N., Roshan, R., & Vatsyayan, D. (2024). Leptogenesis, dark matter and gravitational waves from discrete symmetry breaking. J. Cosmol. Astropart. Phys., 06(6), 029–25pp.
Abstract: We analyse a model that connects the neutrino sector and the dark sector of the universe via a mediator 41., stabilised by a discrete Z4 symmetry that breaks to a remnant Z2 upon 41. acquiring a non -zero vacuum expectation value (v phi). The model accounts for the observed baryon asymmetry of the universe via additional contributions to the canonical Type -I leptogenesis. The Z4 symmetry breaking scale (v phi) in the model not only establishes a connection between the neutrino sector and the dark sector, but could also lead to gravitational wave signals that are within the reach of current and future experimental sensitivities.
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Nacher, E., Briz, J. A., Nerio, A. N., Perea, A., Tavora, V. G., Tengblad, O., et al. (2024). Characterization of a novel proton-CT scanner based on Silicon and LaBr3(Ce) detectors. Eur. Phys. J. Plus, 139(5), 404–9pp.
Abstract: Treatment planning systems at proton-therapy centres entirely use X-ray computed tomography (CT) as primary imaging technique to infer the proton treatment doses to tumour and healthy tissues. However, proton stopping powers in the body, as derived from X-ray images, suffer from important proton-range uncertainties. In order to reduce this uncertainty in range, one could use proton-CT images instead. The main goal of this work is to test the capabilities of a newly-developed proton-CT scanner, based on the use of a set of tracking detectors and a high energy resolution scintillator for the residual energy of the protons. Different custom-made phantoms were positioned at the field of view of the scanner and were irradiated with protons at the CCB proton-therapy center in Krakow. We measured with the phantoms at different angles and produced sinograms that were used to obtain reconstructed images by Filtered Back-Projection. The obtained images were used to determine the capabilities of our scanner in terms of spatial resolution and proton Relative Stopping Power (RSP) mapping and validate its use as proton-CT scanner. The results show that the scanner can produce medium-high quality images, with spatial resolution better than 2 mm in radiography, below 3 mm in tomography and resolving power in the RSP comparable to other state-of-the-art pCT scanners.
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Lerendegui-Marco, J., Babiano-Suarez, V., Balibrea-Correa, J., Caballero, L., Calvo, D., Ladarescu, I., et al. (2024). Simultaneous Gamma-Neutron Vision device: a portable and versatile tool for nuclear inspections. EPJ Tech. Instrum., 11(1), 2–17pp.
Abstract: This work presents GN-Vision, a novel dual gamma-ray and neutron imaging system, which aims at simultaneously obtaining information about the spatial origin of gamma-ray and neutron sources. The proposed device is based on two position sensitive detection planes and exploits the Compton imaging technique for the imaging of gamma-rays. In addition, spatial distributions of slow- and thermal-neutron sources (<100 eV) are reconstructed by using a passive neutron pin-hole collimator attached to the first detection plane. The proposed gamma-neutron imaging device could be of prime interest for nuclear safety and security applications. The two main advantages of this imaging system are its high efficiency and portability, making it well suited for nuclear applications were compactness and real-time imaging is important. This work presents the working principle and conceptual design of the GN-Vision system and explores, on the basis of Monte Carlo simulations, its simultaneous gamma-ray and neutron detection and imaging capabilities for a realistic scenario where a Cf-252 source is hidden in a neutron moderating container.
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Heidari, N., Hassanabadi, H., Araujo Filho, A. A., Kriz, J., Zare, S., & Porfirio, P. J. (2024). Gravitational signatures of a non-commutative stable black hole. Phys. Dark Universe, 43, 101382–13pp.
Abstract: This work investigates several key aspects of a non-commutative theory with mass deformation. We calculate thermodynamic properties of the system and compare our results with recent literature. We examine the quasinormal modes of massless scalar perturbations using two approaches: the WKB approximation and the Poschl-Teller fitting method. Our results indicate that stronger non-commutative parameters lead to slower damping oscillations of gravitational waves and higher partial absorption cross sections. Furthermore, we study the geodesics of massless and massive particles, highlighting that the non-commutative parameter (R) significantly impacts the paths of light and event horizons. Also, we calculate the shadows, which show that larger values of (R) correspond to larger shadow radii, and provide some constraints on (R) applying the observation of Sgr A* from the Event Horizon Telescope. Finally, we explore the deflection angle in this context.
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Araujo Filho, A. A. (2024). Analysis of a regular black hole in Verlinde's gravity. Class. Quantum Gravity, 41(1), 015003–30pp.
Abstract: This work focuses on the examination of a regular black hole within Verlinde's emergent gravity, specifically investigating the Hayward-like (modified) solution. The study reveals the existence of three horizons under certain conditions, i.e. an event horizon and two Cauchy horizons. Our results indicate regions which phase transitions occur based on the analysis of heat capacity and Hawking temperature. To compute the latter quantity, we utilize three distinct methods: the surface gravity approach, Hawking radiation, and the application of the first law of thermodynamics. In the case of the latter approach, it is imperative to introduce a correction to ensure the preservation of the Bekenstein-Hawking area law. Geodesic trajectories and critical orbits (photon spheres) are calculated, highlighting the presence of three light rings. Additionally, we investigate the black hole shadows. Furthermore, the quasinormal modes are explored using third- and sixth-order Wentzel-Kramers-Brillouin approximations. In particular, we observe stable and unstable oscillations for certain frequencies. Finally, in order to comprehend the phenomena of time-dependent scattering in this scenario, we provide an investigation of the time-domain solution.
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