Journal of Physics G最新文献

{"title":"Constrained neutrino mass matrix and Majorana phases","authors":"Pralay Chakraborty, Manash Dey, Subhankar Roy","doi":"10.1088/1361-6471/ad074c","DOIUrl":"https://doi.org/10.1088/1361-6471/ad074c","url":null,"abstract":"Abstract We endeavour to constrain the neutrino mass matrix on the phenomenological ground and procure model-independent textures by emphasizing on the simple linear relationships among the mass matrix elements. These simple textures predict the two Majorana phases. In this regard, two types of parametrization of neutrino mass matrix: general and exponential are employed. We obtain fifty-three predictive neutrino mass matrix textures, out of which twenty-eight are associated with the general parametrization, and the rest belong to the exponential one. Apart from Type-A/P textures, the rest deal with the prediction of a few other oscillation parameters as well. We try to realize the proposed textures in the light of $A_4$, $Delta,(27)$ and $T_7$ symmetry groups.","PeriodicalId":16770,"journal":{"name":"Journal of Physics G","volume":"21 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136376201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on muon MDM and lepton EDM in BLMSSM via the mass insertion approximation","authors":"Xi Wang, Xin-Xin Long, Yi-Tong Wang, Tong-Tong Wang, Hai-Bin Zhang, Tai-Fu Feng, Rong-Xiang Zhang, Shu-Min Zhao","doi":"10.1088/1361-6471/ad06c8","DOIUrl":"https://doi.org/10.1088/1361-6471/ad06c8","url":null,"abstract":"Abstract In the framework of the MSSM extension with local gauged baryon and lepton numbers (BLMSSM), we calculate the muon anomalous magnetic dipole moment (MDM) and lepton $(e, mu, tau)$ electric dipole moment (EDM), and discuss how the muon MDM and lepton EDM depend on the parameters within the mass insertion approximation. Among many parameters, $tan{beta}$,~$g_L$,~$m_L$ and $mu_H$ are more sensitive parameters for $a^{BL}_{mu}$. Considering the experimental limitations, our best numerical result of $a^{BL}_{mu}$ is around $2.5 times 10^{-9}$, which can well compensate the departure between the experiment data and standard model (SM) prediction. The CP violating phases in BLMSSM are more than those in the MSSM, including new parameters $theta_{mu_L}$ and $theta_{L}$. They can give large contributions, which play an important role in exploring the source of CP violation and probing new physics beyond SM.","PeriodicalId":16770,"journal":{"name":"Journal of Physics G","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134973484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electron scattering and neutrino physics","authors":"Ankowski, A. M., Ashkenazi, A., Bacca, S., Barrow, J. L., Betancourt, M., Bodek, A., Christy, M. E., Dytman, L. Doria. S., Friedland, A., Hen, O., Horowitz, C. J., Jachowicz, N., Ketchum, W., Lux, T., Mahn, K., Mariani, C., Newby, J., Pandey, V., Papadopoulou, A., Radicioni, E., Sánchez, F., Sfienti, C., Udías, J. M., Weinstein, L., Alvarez-Ruso, L., Amaro, J. E., Argüelles, C. A., Balantekin, A. B., Bolognesi, S., Brdar, V., Butti, P., Carey, S., Djurcic, Z., Dvornikov, O., Edayath, S., Gardiner, S., Isaacson, J., Jay, W., Klustová, A., McFarland, K. S., Nikolakopoulos, A., Norrick, A., Pastore, S., Paz, G., Reno, M. H., Simo, I. Ruiz, Sobczyk, J. E., Sousa, A., Toro, N., Tsai, Y. -D., Wagman, M., Walsh, J. G., Yang, G.","doi":"10.1088/1361-6471/acef42","DOIUrl":"https://doi.org/10.1088/1361-6471/acef42","url":null,"abstract":"A thorough understanding of neutrino-nucleus scattering physics is crucial for the successful execution of the entire US neutrino physics program. Neutrino-nucleus interaction constitutes one of the biggest systematic uncertainties in neutrino experiments - both at intermediate energies affecting long-baseline Deep Underground Neutrino Experiment (DUNE), as well as at low energies affecting coherent scattering neutrino program - and could well be the difference between achieving or missing discovery level precision. To this end, electron-nucleus scattering experiments provide vital information to test, assess and validate different nuclear models and event generators intended to be used in neutrino experiments. In this white paper, we highlight connections between electron- and neutrino-nucleus scattering physics at energies ranging from 10s of MeV to a few GeV, review the status of ongoing and planned electron scattering experiments, identify gaps, and layout a path forward that benefits the neutrino community. We also highlight the systemic challenges with respect to the divide between the nuclear and high-energy physics communities and funding that presents additional hurdle in mobilizing these connections to the benefit of neutrino programs.","PeriodicalId":16770,"journal":{"name":"Journal of Physics G","volume":"62 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134972399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fermion mass hierarchy and mixing in simplified grand gauge-Higgs unification","authors":"Nobuhito Maru, Haruki Takahashi, Yoshiki Yatagai","doi":"10.1088/1361-6471/ad05d9","DOIUrl":"https://doi.org/10.1088/1361-6471/ad05d9","url":null,"abstract":"Abstract Grand gauge-Higgs unification of five dimensional SU(6) gauge theory on an orbifold S 1 /Z 2 with localized gauge kinetic terms is discussed. The Standard model (SM) fermions on the boundaries and some massive bulk fermions coupling to the SM fermions are introduced. The number of the bulk fermions is reduced compared to the previous model, which reproduces the generation mixing of the SM fermions in addition to the SM fermion mass hierarchy by mild tuning the bulk masses and parameters of the localized gauge kinetic terms.","PeriodicalId":16770,"journal":{"name":"Journal of Physics G","volume":"15 9","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135365577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analyzing beam-gas interactions in an H₂ ⁺ cyclotron beam","authors":"Pedro Calvo, Daniel Winklehner, Concepción Oliver","doi":"10.1088/1361-6471/acfe8f","DOIUrl":"https://doi.org/10.1088/1361-6471/acfe8f","url":null,"abstract":"Abstract For the Isotope Decay At Rest (IsoDAR) experiment in neutrino physics (searching for sterile neutrinos), we have developed a novel compact isochronous cyclotron with direct injection through an axially embedded RFQ. For IsoDAR to be decisive within five years of running, 10 mA of protons, cw at 80% duty factor are needed on a neutrino production target. To alleviate space charge in the cyclotron driver, we accelerate 5 mA of <?CDATA ${{rm{H}}}_{2}^{+}$?> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" overflow=\"scroll\"> <mml:msubsup> <mml:mrow> <mml:mi mathvariant=\"normal\">H</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> </mml:mrow> </mml:msubsup> </mml:math> , to be broken up into 10 mA of protons after extraction from the cyclotron. An open question that we are answering with this paper is whether the beam losses from gas-stripping (the removal of electrons from <?CDATA ${{rm{H}}}_{2}^{+}$?> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" overflow=\"scroll\"> <mml:msubsup> <mml:mrow> <mml:mi mathvariant=\"normal\">H</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> </mml:mrow> </mml:msubsup> </mml:math> through the interaction of the beam ions with the residual gas in the accelerator) are going to be a significant challenge. Using a newly added feature to the well-established Object-Oriented Parallel Accelerator Library code, we calculate gas-stripping losses in the IsoDAR cyclotron using realistic beam distributions, magnetic fields, gas composition, and pressure. We show that to maintain losses due to dissociation below 1% over the entire acceleration region, a vacuum of at least 6 × 10 −7 mbar is required.","PeriodicalId":16770,"journal":{"name":"Journal of Physics G","volume":"42 6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135824173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spin dynamics of triaxial odd mass nuclei with quasiparticle alignments","authors":"Radu Budaca, Andreea Ioana Budaca","doi":"10.1088/1361-6471/acfcd0","DOIUrl":"https://doi.org/10.1088/1361-6471/acfcd0","url":null,"abstract":"Abstract The dynamics of medium odd-mass nuclei with triaxial cores and non-axial rigid quasiparticle alignments is investigated in a semiclassical approach. Quantum observables are computed with a Schrödinger equation, constructed from the classical picture, which has the total angular momentum projection as a continuous variable. The separation of potential energy as a function of the chosen variable allows the phenomenological interpretation of the spectra in terms of wobbling oscillations and tilted axis rotations. The experimental realization of the model is presented for the collective bands of 105 Pd, 133 La and 135 Pr nuclei. In particular, a novel transitional phase associated with a tilted axis wobbling was suggested for the 133 La nucleus.","PeriodicalId":16770,"journal":{"name":"Journal of Physics G","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135824319","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Asymmetric particle-antiparticle Dirac equation: second quantization","authors":"Gustavo Rigolin","doi":"10.1088/1361-6471/ad0313","DOIUrl":"https://doi.org/10.1088/1361-6471/ad0313","url":null,"abstract":"Abstract We build the fully relativistic quantum field theory related to the asymmetric Dirac fields. These fields are solutions of the asymmetric Dirac equation, a Lorentz covariant Dirac-like equation whose positive and “negative” frequency plane wave solutions’ dispersion relations are no longer degenerate. At the second quantization level, we show that this implies that particles and antiparticles sharing the same wave number have different energies and momenta. In spite of that, we prove that by properly fixing the values of the relativistic invariants that define the asymmetric Dirac free field Lagrangian density, we can build a consistent, fully relativistic, and renormalizable quantum electrodynamics (QED) that is empirically equivalent to the standard QED. We discuss the reasons and implications of this non-trivial equivalence, exploring qualitatively other scenarios in which the asymmetric Dirac fields may lead to beyond the standard model predictions. We give a complete account of how the asymmetric Dirac fields and the corresponding annihilation and creation operators transform under improper Lorentz transformations (parity and time reversal operations) and under the charge conjugation operation. We also prove that the present theory respects the CPT theorem.present theory respects the CPT theorem.&amp;#xD;","PeriodicalId":16770,"journal":{"name":"Journal of Physics G","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135853741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative study of neural network and model averaging methods in nuclear β-decay half-life predictions","authors":"Weifeng Li, Xiaoyan Zhang, Y Niu, Zhongming Niu","doi":"10.1088/1361-6471/ad0314","DOIUrl":"https://doi.org/10.1088/1361-6471/ad0314","url":null,"abstract":"Abstract Nuclear $beta$-decay half-lives are investigated using the two-hidden-layer neural network and compared with the model averaging method. By carefully designing the input and hidden layers of the neural network, the neural network achieves better accuracy of nuclear $beta$-decay half-life predictions and well eliminates the too strong odd-even staggering predicted by the previous neural networks. For nuclei with half-lives less than $1$ second, the neural network can describe experimental half-lives within $1.6$ times. The half-life predictions of the neural network are further tested with the newly measured half-lives, demonstrating its reliable extrapolation ability not far from the training region. Compared to the model averaging method, the neural network has higher accuracy and smaller uncertainties of half-life predictions in the known region. When extrapolated to the unknown region, the half-life uncertainties of the neural network are still smaller than those of the model averaging method within about $5 - 10$ steps for nuclei with $35 lesssim Z lesssim 90$, while the model averaging method has smaller half-life uncertainties for nuclei near the drip line.","PeriodicalId":16770,"journal":{"name":"Journal of Physics G","volume":"87 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135853118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Asymmetric particle-antiparticle Dirac equation: first quantization","authors":"Gustavo Rigolin","doi":"10.1088/1361-6471/ad0312","DOIUrl":"https://doi.org/10.1088/1361-6471/ad0312","url":null,"abstract":"Abstract We derive a Dirac-like equation, the asymmetric Dirac equation, where particles and antiparticles sharing the same wave number have different energies and momenta. We show that this equation is Lorentz covariant under proper Lorentz transformations (boosts and spatial rotations) and also determine the corresponding transformation law for its wave function. We obtain a formal connection between the asymmetric Dirac equation and the standard Dirac equation and we show that by properly adjusting the free parameters of the present wave equation we can make it reproduce the predictions of the usual Dirac equation. We show that the rest mass of a particle in the theoretical framework of the asymmetric Dirac equation is a function of a set of four parameters, which are relativistic invariants under proper Lorentz transformations. These four parameters are the analog to the mass that appears in the standard Dirac equation. We prove that in order to guarantee the covariance of the asymmetric Dirac equation under parity and time reversal operations (improper Lorentz transformations) as well as under the charge conjugation operation, these four parameters change sign in exactly the same way as the four components of a four-vector. The mass, though, being a function of the square of those parameters remains an invariant. We also extensively study the free particle plane wave solutions to the asymmetric Dirac equation and derive its energy, helicity, and spin projection operators as well as several Gordon’s identities. The hydrogen atom is solved in the present context after applying the minimal coupling prescription to the asymmetric Dirac equation, which also allows us to appropriately obtain its non-relativistic limit.&amp;#xD;","PeriodicalId":16770,"journal":{"name":"Journal of Physics G","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135853902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The top quark chromomagnetic dipole moment in the SM from the 4-body vertex function","authors":"Javier Montano, Fernando Ramı́rez-Zavaleta, E. S. Tututi, Everardo Urquiza-Trejo","doi":"10.1088/1361-6471/acfc26","DOIUrl":"https://doi.org/10.1088/1361-6471/acfc26","url":null,"abstract":"Abstract A new proposal to compute the anomalous chromomagnetic dipole moment of the top quark, <?CDATA ${hat{mu }}_{t}$?> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" overflow=\"scroll\"> <mml:msub> <mml:mrow> <mml:mover accent=\"true\"> <mml:mrow> <mml:mi>μ</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>ˆ</mml:mo> </mml:mrow> </mml:mover> </mml:mrow> <mml:mrow> <mml:mi>t</mml:mi> </mml:mrow> </mml:msub> </mml:math> , in the Standard Model is presented. On the basis of the five-dimensional effective Lagrangian operator that characterizes the quantum-loop induced chromodipolar vertices <?CDATA ${gt}bar{t}$?> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" overflow=\"scroll\"> <mml:mi mathvariant=\"italic\">gt</mml:mi> <mml:mover accent=\"true\"> <mml:mrow> <mml:mi>t</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>¯</mml:mo> </mml:mrow> </mml:mover> </mml:math> and <?CDATA ${ggt}bar{t}$?> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" overflow=\"scroll\"> <mml:mi mathvariant=\"italic\">ggt</mml:mi> <mml:mover accent=\"true\"> <mml:mrow> <mml:mi>t</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>¯</mml:mo> </mml:mrow> </mml:mover> </mml:math> , the <?CDATA ${hat{mu }}_{t}$?> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" overflow=\"scroll\"> <mml:msub> <mml:mrow> <mml:mover accent=\"true\"> <mml:mrow> <mml:mi>μ</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>ˆ</mml:mo> </mml:mrow> </mml:mover> </mml:mrow> <mml:mrow> <mml:mi>t</mml:mi> </mml:mrow> </mml:msub> </mml:math> anomaly is derived via radiative correction at the 1-loop level from the non-Abelian 4-body vertex function <?CDATA ${ggt}bar{t}$?> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" overflow=\"scroll\"> <mml:mi mathvariant=\"italic\">ggt</mml:mi> <mml:mover accent=\"true\"> <mml:mrow> <mml:mi>t</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>¯</mml:mo> </mml:mrow> </mml:mover> </mml:math> . We evaluate <?CDATA ${hat{mu }}_{t}(s)$?> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" overflow=\"scroll\"> <mml:msub> <mml:mrow> <mml:mover accent=\"true\"> <mml:mrow> <mml:mi>μ</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>ˆ</mml:mo> </mml:mrow> </mml:mover> </mml:mrow> <mml:mrow> <mml:mi>t</mml:mi> </mml:mrow> </mml:msub> <mml:mo stretchy=\"false\">(</mml:mo> <mml:mi>s</mml:mi> <mml:mo stretchy=\"false\">)</mml:mo> </mml:math> as a function of the energy scale s = ± E 2 , for E = [10, 1000] GeV, taking into account the running of the quark masses and alpha strong through the <?CDATA $overline{mathrm{MS}}$?> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" overflow=\"scroll\"> <mml:mover accent=\"true\"> <mml:mrow> <mml:mi>MS</mml:mi> </mml:mrow> <mml:mrow> <mml:mo stretchy=\"true\">¯</mml:mo> </mml:mrow> </mml:mover> </mml:math> scheme. In particular, we find that at the typical energy scale E = m Z for high-energy physics, similarly to <?CDATA ${alpha }_{s}({m}_{Z}^{2})$?> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" overflow=\"scroll\"> <mml:msub> <mml:mrow> <mml:mi>α</mml:mi> </mml:mrow> <mml:mrow>","PeriodicalId":16770,"journal":{"name":"Journal of Physics G","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135923592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}