Strangeness in the proton from <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow> <mml:mrow> <mml:mi>W</mml:mi> <mml:mo>+</mml:mo> </mml:mrow> <mml:mi>charm</mml:mi> </mml:mrow> </mml:math> production and SIDIS data

We perform a global QCD analysis of unpolarized parton distribution functions (PDFs) in the proton, including new <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"> <a:mrow> <a:mrow> <a:mi>W</a:mi> <a:mo>+</a:mo> </a:mrow> <a:mi>charm</a:mi> </a:mrow> </a:math> production data from <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"> <c:mi>p</c:mi> <c:mi>p</c:mi> </c:math> collisions at the LHC and semi-inclusive pion and kaon production data in lepton-nucleon deep-inelastic scattering, both of which have been suggested for constraining the strange quark PDF. Compared with a baseline global fit that does not include these datasets, the new analysis reduces the uncertainty on the strange quark distribution over the range <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"> <e:mn>0.01</e:mn> <e:mo>&lt;</e:mo> <e:mi>x</e:mi> <e:mo>&lt;</e:mo> <e:mn>0.3</e:mn> </e:math> , and provides a consistent description of processes sensitive to strangeness in the proton. Including the new datasets, the ratio of strange to nonstrange sea quark distributions is <g:math xmlns:g="http://www.w3.org/1998/Math/MathML" display="inline"> <g:msub> <g:mi>R</g:mi> <g:mi>s</g:mi> </g:msub> <g:mo>=</g:mo> <g:mo stretchy="false">(</g:mo> <g:mi>s</g:mi> <g:mo>+</g:mo> <g:mover accent="true"> <g:mi>s</g:mi> <g:mo stretchy="false">¯</g:mo> </g:mover> <g:mo stretchy="false">)</g:mo> <g:mo>/</g:mo> <g:mo stretchy="false">(</g:mo> <g:mover accent="true"> <g:mi>u</g:mi> <g:mo stretchy="false">¯</g:mo> </g:mover> <g:mo>+</g:mo> <g:mover accent="true"> <g:mi>d</g:mi> <g:mo stretchy="false">¯</g:mo> </g:mover> <g:mo stretchy="false">)</g:mo> <g:mo>=</g:mo> <g:mo stretchy="false">{</g:mo> <g:mn>0.7</g:mn> <g:msubsup> <g:mn>2</g:mn> <g:mrow> <g:mo>−</g:mo> <g:mn>0.34</g:mn> </g:mrow> <g:mrow> <g:mo>+</g:mo> <g:mn>0.52</g:mn> </g:mrow> </g:msubsup> <g:mo>,</g:mo> <g:mn>0.4</g:mn> <g:msubsup> <g:mn>6</g:mn> <g:mrow> <g:mo>−</g:mo> <g:mn>0.20</g:mn> </g:mrow> <g:mrow> <g:mo>+</g:mo> <g:mn>0.30</g:mn> </g:mrow> </g:msubsup> <g:mo>,</g:mo> <g:mn>0.3</g:mn> <g:msubsup> <g:mn>2</g:mn> <g:mrow> <g:mo>−</g:mo> <g:mn>0.15</g:mn> </g:mrow> <g:mrow> <g:mo>+</g:mo> <g:mn>0.23</g:mn> </g:mrow> </g:msubsup> <g:mo stretchy="false">}</g:mo> </g:math> for <u:math xmlns:u="http://www.w3.org/1998/Math/MathML" display="inline"> <u:mi>x</u:mi> <u:mo>=</u:mo> <u:mo stretchy="false">{</u:mo> <u:mn>0.01</u:mn> <u:mo>,</u:mo> <u:mn>0.04</u:mn> <u:mo>,</u:mo> <u:mn>0.1</u:mn> <u:mo stretchy="false">}</u:mo> </u:math> at <y:math xmlns:y="http://www.w3.org/1998/Math/MathML" display="inline"> <y:msup> <y:mi>Q</y:mi> <y:mn>2</y:mn> </y:msup> <y:mo>=</y:mo> <y:mn>4</y:mn> <y:mtext> </y:mtext> <y:mtext> </y:mtext> <y:msup> <y:mrow> <y:mi>GeV</y:mi> </y:mrow> <y:mrow> <y:mn>2</y:mn> </y:mrow> </y:msup> </y:math> . The data place more stringent constraints on the strange asymmetry <ab:math xmlns:ab="http://www.w3.org/1998/Math/MathML" display="inline"> <ab:mi>s</ab:mi> <ab:mo>−</ab:mo> <ab:mover accent="true"> <ab:mi>s</ab:mi> <ab:mo stretchy="false">¯</ab:mo> </ab:mover> </ab:math> , which is found to be consistent with zero in this range.