We report limits on the so-called neutrino charge radius squared. While the straight-forward definition of a neutrino charge radius has been proven to be gauge-dependent and, hence, unphysical (LEE 1977C), there have been recent attempts to define a physically observable neutrino charge radius (BERNABEU 2000, BERNABEU 2002). The issue is still controversial (FUJIKAWA 2003, BERNABEU 2003). A more general interpretation of the experimental results is that they are limits on certain nonstandard contributions to neutrino scattering.

S066CRD VALUE ($ 10^{-32} $ cm${}^{2}$) CL% DOCUMENT ID TECN  COMMENT $2.2$ ${}^{+2.4}_{-2.3}$ 1 ATZORI-CORONA 2025   FIT Global fit to ${{\mathit \nu}}$ES, CE${{\mathit \nu}}$NS data • • We do not use the following data for averages, fits, limits, etc. • • $-70.01\text{ to }28.52 $ 90 2 DEMIRCI 2025 A   Solar ${{\mathit \nu}}−{{\mathit e}}$ scattering $-54.36\text{ to }12.90 $ 90 3 DEMIRCI 2025 A   Solar ${{\mathit \nu}}−{{\mathit e}}$ scattering $-27.5\text{ to }3 $ 90 4 CADEDDU 2018   ${{\mathit \nu}_{{{\mu}}}}$ coherent scat. on ${}^{}\mathrm {CsI}$ $-2.1\text{ to }3.3 $ 90 5 DENIZ 2010   TEXO Reactor ${{\overline{\mathit \nu}}_{{{e}}}}{{\mathit e}}$ $-0.53\text{ to }0.68 $ 90 6 HIRSCH 2003   ${{\mathit \nu}_{{{\mu}}}}{{\mathit e}}$ scat. $-8.2\text{ to }9.9 $ 90 7 HIRSCH 2003   anomalous ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \nu}}{{\overline{\mathit \nu}}}{{\mathit \gamma}}$ $-2.97\text{ to }4.14 $ 90 8 AUERBACH 2001   LSND ${{\mathit \nu}_{{{e}}}}$ ${{\mathit e}}$ $\rightarrow$ ${{\mathit \nu}_{{{e}}}}{{\mathit e}}$ $-0.6\text{ to }0.6 $ 90 VILAIN 1995 B   CHM2 ${{\mathit \nu}_{{{\mu}}}}{{\mathit e}}$ elastic scat. $0.9$ $\pm2.7$ ALLEN 1993   CNTR LAMPF ${{\mathit \nu}}$ ${{\mathit e}}$ $\rightarrow$ ${{\mathit \nu}}{{\mathit e}}$ $<2.3$ 95 MOURAO 1992   ASTR HOME/KAM2 ${{\mathit \nu}}$ rates $<7.3$ 90 9 VIDYAKIN 1992   CNTR Reactor ${{\overline{\mathit \nu}}}$ ${{\mathit e}}$ $\rightarrow$ ${{\overline{\mathit \nu}}}{{\mathit e}}$ $1.1$ $\pm2.3$ ALLEN 1991   CNTR Repl. by ALLEN 1993 $-1.1$ $\pm1.0$ 10 AHRENS 1990   CNTR ${{\mathit \nu}_{{{\mu}}}}{{\mathit e}}$ elastic scat. $-0.3$ $\pm1.5$ 10 DORENBOSCH 1989   CHRM ${{\mathit \nu}_{{{\mu}}}}{{\mathit e}}$ elastic scat. 11 GRIFOLS 1989 B   ASTR SN 1987A 1  ATZORI-CORONA 2025 reports the limit of ${{\mathit \nu}_{{{e}}}}$ charge radius squared by performing a global fit to ${{\mathit \nu}}$ES and CE${{\mathit \nu}}$NS data from COHERENT, CONUS+, TEXONO, LSND, LAMPF, CHARM-II, BNL-E734, and CCFR. Limits for the ${{\mathit \nu}_{{{\mu}}}}$ and ${{\mathit \nu}_{{{\tau}}}}$ charge radii squared are also reported. 2  DEMIRCI 2025A analyzed 1540 kg$\cdot{}$y of ${}^{}\mathrm {Xe}$ exposure of the TPC-based PandaX-4T dark matter search. Elastic solar neutrino-electron scattering is used to derive a bound on the square of the charge radius of neutrinos. 3  DEMIRCI 2025A analyzed 1600 kg$\cdot{}$y of ${}^{}\mathrm {Xe}$ exposure of the TPC-based XENONnT dark matter search. Elastic solar neutrino-electron scattering is used to derive a bound on the square of the charge radius of neutrinos. 4  CADEDDU 2018 use the data of the COHERENT experiment, AKIMOV 2018. The limit is $\langle $r${}^{2}_{{{\mathit \nu}}}\rangle $ for ${{\mathit \nu}_{{{\mu}}}}$ obtained from the time-dependent data. Weaker limits were obtained for charge radii of ${{\mathit \nu}_{{{e}}}}$ and for transition charge radii. The published value was divided by 2 to conform to the convention of this table. 5  DENIZ 2010 observe reactor ${{\overline{\mathit \nu}}_{{{e}}}}{{\mathit e}}$ scattering with recoil kinetic energies $3 - 8$ MeV using CsI(Tl) detectors. The observed rate and spectral shape are consistent with the Standard Model prediction, leading to the reported constraint on ${{\overline{\mathit \nu}}_{{{e}}}}$ charge radius. 6  Based on analysis of CCFR 98 results. Limit is on $\langle $r${}^{2}_{V}\rangle $ + $\langle $r${}^{2}_{A}\rangle $. The CHARM II and E734 at BNL results are reanalyzed, and weaker bounds on the charge radius squared than previously published are obtained. The NuTeV result is discussed; when tentatively interpreted as ${{\mathit \nu}_{{{\mu}}}}$ charge radius it implies $\langle $r${}^{2}_{V}\rangle $ + $\langle $r${}^{2}_{A}\rangle $ = ($4.20$ $\pm1.64$) ${\times }$ 10 ${}^{-33}$ cm${}^{2}$. 7  Results of LEP-2 are interpreted as limits on the axial-vector charge radius squared of a Majorana ${{\mathit \nu}_{{{\tau}}}}$. Slightly weaker limits for both vector and axial-vector charge radius squared are obtained for the Dirac case, and somewhat weaker limits are obtained from the analysis of lower energy data (LEP-1.5 and TRISTAN). 8  AUERBACH 2001 measure ${{\mathit \nu}_{{{e}}}}{{\mathit e}}$ elastic scattering with LSND detector. The cross section agrees with the Standard Model expectation, including the charge and neutral current interference. The 90$\%$ CL applies to the range shown. 9  VIDYAKIN 1992 limit is from a ${{\mathit e}}{{\overline{\mathit \nu}}}$ elastic scattering experiment. No experimental details are given except for the cross section from which this limit is derived. Signal/noise was 1/10. The limit uses sin$^2\theta _{\mathit W}$ = $0.23$ as input. 10  Result is obtained from reanalysis given in ALLEN 1991, followed by our reduction to obtain 1$~\sigma $ errors. 11  GRIFOLS 1989B sets a limit of $\langle \mathit r{}^{2}\rangle $ $<~0.2 \times 10^{-32}~$cm${}^{2}$ for right-handed neutrinos.

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