High Energy Physics - Lattice
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Showing new listings for Thursday, 14 November 2024
- [1] arXiv:2411.08044 [pdf, html, other]
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Title: A graphical user interface software for lattice QCD based on Python acceleration technologySubjects: High Energy Physics - Lattice (hep-lat)
A graphical user interface (GUI) software is provided for lattice QCD simulations, aimed at streamlining the process. The current version of the software employs the Metropolis algorithm with the Wilson gauge action. It is implemented in Python, utilizing Just-In-Time (JIT) compilation to enhance computational speed while preserving Python's simplicity and extensibility. Additionally, the program supports parallel computations to evaluate physical quantities at different inverse coupling \(\beta\) values, allowing users to specify the number of CPU cores. The software also enables the use of various initial conditions, as well as the specification of the save directory, file names, and background settings. Through this software, users can observe the configurations and behaviors of the plaquette under different \(\beta\) values.
- [2] arXiv:2411.08461 [pdf, html, other]
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Title: Use QUDA for lattice QCD calculation with PythonComments: 11 pages, 3 listingsSubjects: High Energy Physics - Lattice (hep-lat)
We developed PyQUDA, a Python wrapper for QUDA written in Cython, designed to facilitate lattice QCD calculations using the Python programming language. PyQUDA leverages the optimized linear algebra capabilities of NumPy/CuPy/PyTorch, along with the highly optimized lattice QCD operations provided by QUDA to accelerate research. This integration simplifies the process of writing calculation codes, enabling researchers to build more complex Python packages like EasyDistillation for specific physics objectives. PyQUDA supports a range of lattice QCD operations, including hybrid Monte Carlo (HMC) with N-flavor clover/HISQ fermions and inversion for the Wilson/clover/HISQ fermion action with the multigrid solver. It also includes utility functions for reading lattice QCD data stored in Chroma, MILC, and $\chi$QCD formats. Type hints are supported by stub files and multi-GPU support is provided through mpi4py.
- [3] arXiv:2411.08646 [pdf, html, other]
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Title: $T_{cc}^+$ via the plane wave approach and including diquark-antidiquark operatorsComments: 9 pages. Proceedings of the 41st International Symposium on Lattice Field Theory, LATTICE2024, 28th July -3rd August, 2024, University of Liverpool, UKSubjects: High Energy Physics - Lattice (hep-lat)
The determination of the $DD^{*}$ scattering amplitude from lattice QCD is complicated by long-range interactions. In particular, the Lüscher method is no longer applicable in the kinematical region close to the left-hand cut. We tackle this problem by adopting plane-wave and effective-field-theoretic methods, which also address partial wave mixing. In addition, we incorporate a diquark-antidiquark interpolator in the operator basis (along with the relevant scattering operators) in order to achieve a better resolution of the energy spectrum. Results show that inclusion of it already has some impact at physical charm quark mass, although it is more significant for larger heavy quark masses, in line with expectations.
- [4] arXiv:2411.08852 [pdf, html, other]
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Title: Strange and charm quark contributions to the muon anomalous magnetic moment in lattice QCD with twisted-mass fermionsC. Alexandrou, S. Bacchio, A. De Santis, A. Evangelista, J. Finkenrath, R. Frezzotti, G. Gagliardi, M. Garofalo, N. Kalntis, B. Kostrzewa, V. Lubicz, F. Pittler, S. Romiti, F. Sanfilippo, S. Simula, N. Tantalo, C. Urbach, U. WengerComments: 33 pages, 18 figures, 3 tablesSubjects: High Energy Physics - Lattice (hep-lat); High Energy Physics - Phenomenology (hep-ph)
We present a lattice calculation of the Hadronic Vacuum Polarization (HVP) contribution of the strange and charm quarks to the anomalous magnetic moment of the muon in isospin symmetric QCD. We employ the gauge configurations generated by the Extended Twisted Mass Collaboration (ETMC) with $N_f = 2 + 1 + 1$ flavors of Wilson-clover twisted-mass quarks at five lattice spacings and at values of the quark mass parameters that are close and/or include the isospin symmetric QCD point of interest. After computing the small corrections necessary to precisely match this point, and carrying out an extrapolation to the continuum limit based on the data at lattice spacings $a \simeq 0.049, 0.057, 0.068, 0.080$~fm and spatial lattice sizes up to $L \simeq 7.6$~fm, we obtain $a_\mu^{\rm HVP}(s) = (53.57 \pm 0.63) \times 10^{-10}$ and $a_\mu^{\rm HVP}(c) = (14.56 \pm 0.13) \times 10^{-10}$, for the quark-connected strange and charm contributions, respectively. Our findings agree well with the corresponding results by other lattice groups.
New submissions (showing 4 of 4 entries)
- [5] arXiv:2411.08098 (cross-list from hep-ph) [pdf, html, other]
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Title: A precision evaluation of the $\eta$- and $\eta'$-pole contributions to hadronic light-by-light scattering in the anomalous magnetic moment of the muonComments: 8 pages, 3 figuresSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex); High Energy Physics - Lattice (hep-lat); Nuclear Theory (nucl-th)
Next to the $\pi^0$ pole, $\eta$ and $\eta'$ intermediate states give rise to the leading singularities of the hadronic light-by-light tensor, resulting in sizable contributions to the anomalous magnetic moment of the muon $a_\mu$. The strength of the poles is determined by the respective transition form factors (TFFs) to two (virtual) photons. We present a calculation of these TFFs that implements a number of low- and high-energy constraints, including the $\eta^{(\prime)}\to\gamma\gamma$ decay widths, $\eta^{(\prime)}\to\pi^+\pi^-\gamma$ spectra, chiral symmetry for the $\eta^{(\prime)}\to2(\pi^+\pi^-)$ amplitudes, vector-meson couplings, and asymptotic limits. Crucially, we investigate the role of the leading left-hand singularity generated by the exchange of the $a_2$ tensor meson, yielding, for the first time, an estimate of the associated factorization-breaking corrections. Our final results, $a_\mu^{\eta\text{-pole}}=14.7(9)\times 10^{-11}$ and $a_\mu^{\eta'\text{-pole}}=13.5(7)\times 10^{-11}$, conclude a dedicated effort to evaluate the pseudoscalar-pole contributions to hadronic light-by-light scattering using dispersion relations, amounting to a combined $a_\mu^{\text{PS-poles}}=91.2^{+2.9}_{-2.4}\times 10^{-11}$.
Cross submissions (showing 1 of 1 entries)
- [6] arXiv:2404.14263 (replaced) [pdf, html, other]
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Title: Out-of-equilibrium Chiral Magnetic Effect from simulations on Euclidean latticesComments: 13 pages RevTeX, 7 figures, published versionJournal-ref: Phys.Rev.D 110 (2024) 094508Subjects: High Energy Physics - Lattice (hep-lat); Strongly Correlated Electrons (cond-mat.str-el); High Energy Physics - Theory (hep-th)
The status of the Chiral Magnetic Effect (CME) response in full Quantum Chromodynamics (QCD) has been controversial so far, with previous lattice QCD studies indicating either its strong suppression or vanishing in thermal equilibrium state. We introduce the Euclidean-time correlator of axial charge and electric current as an observable that can be used to study the finite out-of-equilibrium CME response in first-principle lattice QCD simulations with background magnetic field. This observable directly reflects the fact that in the background magnetic field, a state with nonzero axial charge features nonzero electric current. For free fermions, the axial-vector correlator only receives contributions from the Lowest Landau Level, and exhibits a linear dependence on both magnetic field and temperature with a universal coefficient. With an appropriate regularization, non-vanishing axial-vector correlator is compatible with the vanishing of the CME current in thermal equilibrium state with nonzero chiral chemical potential $\mu_5$. We demonstrate that the real-time counterpart of the Euclidean-time axial-vector correlator is intimately related to the real-time form of the axial anomaly equation, which strongly limits possible corrections in full QCD. We present numerical results for the Euclidean-time axial-vector correlator in $SU(2)$ lattice gauge theory with $N_f = 2$ light quark flavours, demonstrating reasonable agreement with free fermion result on both sides of the chiral crossover. The proposed methodology should help to answer the question whether the QCD corrections might be responsible for non-observation of CME in heavy-ion collision experiments such as the RHIC isobar run.
- [7] arXiv:2403.01727 (replaced) [pdf, html, other]
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Title: Identification of the $G(3900)$ as the P-wave $D\bar{D}^*/\bar{D}D^*$ resonanceComments: 8 pages, 4 figures. PRL(in press)Subjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex); High Energy Physics - Lattice (hep-lat); Nuclear Theory (nucl-th)
The BESIII Collaboration recently performed a precise measurement of the $e^+e^-\rightarrow D\bar{D}$ Born cross sections, and confirmed the $G(3900)$ structure reported by BaBar and Belle with high significance. We identify the $G(3900)$ as the first P-wave $\DDbar$ molecular resonance. The experimental and theoretical identification of the P-wave dimeson state holds paramount importance in enhancing our comprehension of the non-perturbative QCD and few-body physics. Its existence is firmly established in a unified meson-exchange model which simultaneously depicts the features of the $\chi_{c1}(3872)$, $Z_c(3900)$ and $T_{cc}(3875)$. This scenario can be directly examined in the $e^+e^-\rightarrow D\bar{D}^*/\bar{D}D^*$ cross section by seeing whether a resonance exists at the threshold. The credibility of the investigations is also ensured by the fact that the P-wave interaction dominantly arises from the well-known long-range pion exchange. Additionally, thanks to the centrifugal barrier, it is easier to form resonances in P-wave than in S-wave. We extensively calculate all systems up to P-wave with various quantum numbers and predict a dense population of the $\DDbar$ and $\DD$ states, where the S-wave $\DDbar$ state with $I^G (J^{PC})=0^- (1^{+-})$, P-wave $\DDbar$ state with $I^G(J^{PC})=0^+(0^{-+})$, and P-wave $\DD$ state with $I(J^P)=0(0^-)$ are more likely to be observed in experiments.
- [8] arXiv:2406.07617 (replaced) [pdf, html, other]
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Title: Chiral Separation Effect from Holographic QCDComments: 18 pages plus appendices, 3 figures, 2 tables. v2 added: referee's comments addressed, matches JHEP versionSubjects: High Energy Physics - Theory (hep-th); High Energy Physics - Lattice (hep-lat); High Energy Physics - Phenomenology (hep-ph)
We analyze the chiral separation effect (CSE) in QCD by using the gauge/gravity duality. In QCD, this effect arises from a combination of chiral anomalies and the axial $U(1)$ anomaly. Due to the axial gluon anomaly, the value of the CSE conductivity is not determined by the anomalies of QCD but receives radiative corrections, which leads to nontrivial dependence on temperature and density. To analyze this dependence, we use different variants of V-QCD, a complex holographic model, carefully fitted to QCD data. We find our results for the anomalous CSE conductivity at small chemical potential and nonzero temperature to be in good qualitative agreement with recent results from lattice QCD simulations. We furthermore give predictions for the behavior of the conductivity at finite (vectorial and axial) chemical potentials.