Electromagnetic contribution to 
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-
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 mixing using lattice 
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>QCD</mml:mi><mml:mo>+</mml:mo><mml:mi>QED</mml:mi></mml:mrow></mml:math>

We utilize the experimentally known difference of the $$\varLambda $$ Λ separation energies of the mirror hypernuclei $${^4_\varLambda \mathrm{He}}$$ Λ 4 He and $${^4_\varLambda \mathrm{H}}$$ Λ 4 H to constrain the $$\varLambda $$ Λ -neutron interaction. We include the leading charge-symmetry breaking (CSB) interaction into our hyperon-nucleon interaction derived within chiral effective field theory at next-to-leading order. In particular, we determine the strength of the two arising CSB contact terms by a fit to the differences of the separation energies of these hypernuclei in the $$0^+$$ 0 + and $$1^+$$ 1 + states, respectively. By construction, the resulting interaction describes all low energy hyperon-nucleon scattering data, the hypertriton and the CSB in $${^4_\varLambda \mathrm{He}}$$ Λ 4 He -$${^4_\varLambda \mathrm{H}}$$ Λ 4 H accurately. This allows us to provide first predictions for the $$\varLambda $$ Λ n scattering lengths, based solely on available hypernuclear data.

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“…In this context, let us mention that there are also lattice QCD calculations of Λ − 0 mixing [30][31][32][33].…”

Section: Csb In Chiral Eftmentioning

confidence: 99%

Constraints on the $$\varLambda $$-Neutron Interaction from Charge Symmetry Breaking in the $$\mathbf {^4_\Lambda \mathrm{He}}$$ - $$\mathbf {^4_\Lambda \mathrm{H}}$$ Hypernuclei

2021

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“…This result was recently confirmed in a QCD+QED lattice calculation [9]. Appreciable ΛN charge symmetry breaking (CSB) is implied by this isospin impurity of the Λ hyperon.…”

mentioning

confidence: 58%

In-medium $Λ$ isospin impurity from charge symmetry breaking in the ${_Λ^4}{\rm H}-{_Λ^4}{\rm He}$ mirror hypernuclei

Schäfer,

Barnea,

Gal

2022

Preprint

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The Λ separation energies in the mirror hypernuclei 4 Λ H-4 Λ He exhibit large charge symmetry breaking (CSB). Analyzing this CSB within pionless effective field theory while using partially conserved baryon-baryon SU(3) flavor symmetry, we deduce a Λ − Σ 0 induced in-medium admixture amplitude AI=1 ≈ 1.5% in the dominantly isospin I = 0 Λ hyperon. Our results confirm the freespace value A (0) I=1 inferred directly within the SU(3) baryon octet by Dalitz and von-Hippel in 1964 and reaffirmed in a recent QCD+QED lattice calculation. Furthermore, exploring the consequences of SU(3) flavor symmetry on the Λ-nucleon interaction, we find that CSB is expected to impact the S = 1 and S = 0 spin channels in opposite directions, with the latter dominating by an order of magnitude. These observations explain a recent deduction of Λ-nucleon CSB strengths.

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“…We note that in this preliminary work we make no attempt to quantify the finite volume or lattice spacing effects in our results. We scale the parameters in our expansion that arise due to EM (note that β EM 0 doesn't contribute to the mixing) as was done in [2] to approximately correct our larger-than-physical EM coupling, and find With our relatively low level of precision at the physical point we cannot resolve much significant mixture of the π 0 with either the η or η , but we can see a small non-zero π 3 content in the η , although also too early to draw any physical conclusions. We also observe some non-trivial admixtures of the η 8 and η 1 occuring in the physical η and η , and since all four numbers are consistent with a parametrization by a single mixing angle, we present a determination of said angle as |θ ηη | = sin −1 (−0.26 ± 0.10) = (−15.1 +5.9…”

Section: Results and Analysismentioning

confidence: 99%

“…Understanding and quantifying this difference for the physical states is important for theoretical and phenomenological studies where interpolating operators are used to project onto the physical states. Furthermore, this type of mixing is directly tied to our understanding of the extent of quark-flavour symmetry breaking in nature, as can be seen explicitly from χPT [1] or flavour-breaking [2] expansions.…”

mentioning

confidence: 99%

State mixing and masses of the $π^0$, $η$ and $η^\prime$ mesons from $n_f=1+1+1$ lattice QCD+QED

Kordov,

Horsley,

Kamleh

et al. 2021

Preprint

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We present a lattice analysis of the light pseudoscalar mesons with consideration for the mixing between the flavour-neutral states π 0 , η and η . We extract the masses and flavour compositions of the pseudoscalar meson nonet in n f = 1 + 1 + 1 lattice QCD+QED around an SU(3)-flavour symmetric point, and observe flavour-symmetry features of the extracted data, along with preliminary extrapolation results for the flavour compositions at physical pion mass via a novel method. A key result of this work is the observed mass splitting between the π 0 and η on our ensembles, which is found to exhibit behaviour that is simply related to the corresponding flavour compositions.

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Electromagnetic contribution to Σ - Λ mixing using lattice QCD+QED

Cited by 14 publications

References 27 publications

Constraints on the $$\varLambda $$-Neutron Interaction from Charge Symmetry Breaking in the $$\mathbf {^4_\Lambda \mathrm{He}}$$ - $$\mathbf {^4_\Lambda \mathrm{H}}$$ Hypernuclei

Constraints on the $$\varLambda $$-Neutron Interaction from Charge Symmetry Breaking in the $$\mathbf {^4_\Lambda \mathrm{He}}$$ - $$\mathbf {^4_\Lambda \mathrm{H}}$$ Hypernuclei

In-medium $Λ$ isospin impurity from charge symmetry breaking in the ${_Λ^4}{\rm H}-{_Λ^4}{\rm He}$ mirror hypernuclei

State mixing and masses of the $π^0$, $η$ and $η^\prime$ mesons from $n_f=1+1+1$ lattice QCD+QED

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