Strangeness-correlations on the pseudocritical line in ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow> <mml:mn>2</mml:mn> <mml:mo>+</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:math> )-flavor QCD
Dennis Bollweg, Heng-Tong Ding, Jishnu Goswami, F. Karsch, Swagato Mukherjee, Péter Petreczky, Christian Schmidt
Abstract
We present some lattice QCD results on first ( <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"> <a:mrow> <a:msubsup> <a:mrow> <a:mi>χ</a:mi> </a:mrow> <a:mrow> <a:mn>1</a:mn> </a:mrow> <a:mrow> <a:mi>i</a:mi> </a:mrow> </a:msubsup> </a:mrow> </a:math> ) and second ( <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"> <c:msubsup> <c:mi>χ</c:mi> <c:mn>2</c:mn> <c:mi>i</c:mi> </c:msubsup> </c:math> ) cumulants of and correlations ( <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"> <e:mrow> <e:msubsup> <e:mrow> <e:mi>χ</e:mi> </e:mrow> <e:mrow> <e:mn>11</e:mn> </e:mrow> <e:mrow> <e:mi>i</e:mi> <e:mi>j</e:mi> </e:mrow> </e:msubsup> </e:mrow> </e:math> ) among net baryon-number ( <g:math xmlns:g="http://www.w3.org/1998/Math/MathML" display="inline"> <g:mi>B</g:mi> </g:math> ), strangeness ( <i:math xmlns:i="http://www.w3.org/1998/Math/MathML" display="inline"> <i:mi>S</i:mi> </i:math> ) and electric charge ( <k:math xmlns:k="http://www.w3.org/1998/Math/MathML" display="inline"> <k:mi>Q</k:mi> </k:math> ) along the pseudocritical line [ <m:math xmlns:m="http://www.w3.org/1998/Math/MathML" display="inline"> <m:msub> <m:mi>T</m:mi> <m:mrow> <m:mi>p</m:mi> <m:mi>c</m:mi> </m:mrow> </m:msub> <m:mo stretchy="false">(</m:mo> <m:msub> <m:mi>μ</m:mi> <m:mi>B</m:mi> </m:msub> <m:mo stretchy="false">)</m:mo> </m:math> ] in the temperature ( <q:math xmlns:q="http://www.w3.org/1998/Math/MathML" display="inline"> <q:mi>T</q:mi> </q:math> )–baryon chemical potential ( <s:math xmlns:s="http://www.w3.org/1998/Math/MathML" display="inline"> <s:msub> <s:mi>μ</s:mi> <s:mi>B</s:mi> </s:msub> </s:math> ) phase diagram of ( <u:math xmlns:u="http://www.w3.org/1998/Math/MathML" display="inline"> <u:mrow> <u:mn>2</u:mn> <u:mo>+</u:mo> <u:mn>1</u:mn> </u:mrow> </u:math> )-flavor QCD. We point out that violations of sum rules among second order cumulants, which hold in the isospin symmetric limit of vanishing electric charge chemical potential, are small along the <w:math xmlns:w="http://www.w3.org/1998/Math/MathML" display="inline"> <w:msub> <w:mi>T</w:mi> <w:mrow> <w:mi>p</w:mi> <w:mi>c</w:mi> </w:mrow> </w:msub> <w:mo stretchy="false">(</w:mo> <w:msub> <w:mi>μ</w:mi> <w:mi>B</w:mi> </w:msub> <w:mo stretchy="false">)</w:mo> </w:math> for the entire range of <ab:math xmlns:ab="http://www.w3.org/1998/Math/MathML" display="inline"> <ab:msub> <ab:mi>μ</ab:mi> <ab:mi>B</ab:mi> </ab:msub> </ab:math> covered in the RHIC beam energy scan. For the strangeness neutral matter produced in heavy-ion collisions this leads to a close relation between <cb:math xmlns:cb="http://www.w3.org/1998/Math/MathML" display="inline"> <cb:msubsup> <cb:mi>χ</cb:mi> <cb:mn>11</cb:mn> <cb:mrow> <cb:mi>B</cb:mi> <cb:mi>S</cb:mi> </cb:mrow> </cb:msubsup> </cb:math> and <eb:math xmlns:eb="http://www.w3.org/1998/Math/MathML" display="inline"> <eb:msubsup> <eb:mi>χ</eb:mi> <eb:mn>11</eb:mn> <eb:mrow> <eb:mi>Q</eb:mi> <eb:mi>S</eb:mi> </eb:mrow> </eb:msubsup> </eb:math> . We compare lattice QCD results for <gb:math xmlns:gb="http://www.w3.org/1998/Math/MathML" display="inline"> <gb:msubsup> <gb:mi>χ</gb:mi> <gb:mn>11</gb:mn> <gb:mrow> <gb:mi>B</gb:mi> <gb:mi>S</gb:mi> </gb:mrow> </gb:msubsup> <gb:mo>/</gb:mo> <gb:msubsup> <gb:mi>χ</gb:mi> <gb:mn>2</gb:mn> <gb:mi>S</gb:mi> </gb:msubsup> </gb:math> along the <ib:math xmlns:ib="http://www.w3.org/1998/Math/MathML" display="inline"> <ib:msub> <ib:mi>T</ib:mi> <ib:mrow> <ib:mi>p</ib:mi> <ib:mi>c</ib:mi> </ib:mrow> </ib:msub> <ib:mo stretchy="false">(</ib:mo> <ib:msub> <ib:mi>μ</ib:mi> <ib:mi>B</ib:mi> </ib:msub> <ib:mo stretchy="false">)</ib:mo> </ib:math> line with preliminary experimental measurements of <mb:math xmlns:mb="http://www.w3.org/1998/Math/MathML" display="inline"> <mb:msubsup> <mb:mi>χ</mb:mi> <mb:mn>11</mb:mn> <mb:mrow> <mb:mi>B</mb:mi> <mb:mi>S</mb:mi> </mb:mrow> </mb:msubsup> <mb:mo>/</mb:mo> <mb:msubsup> <mb:mi>χ</mb:mi> <mb:mn>2</mb:mn> <mb:mi>S</mb:mi> </mb:msubsup> </mb:math> for collision energies <ob:math xmlns:ob="http://www.w3.org/1998/Math/MathML" display="inline"> <ob:mrow> <ob:mn>7.7</ob:mn> <ob:mtext> </ob:mtext> <ob:mtext> </ob:mtext> <ob:mi>GeV</ob:mi> <ob:mo>≤</ob:mo> <ob:msqrt> <ob:mrow> <ob:msub> <ob:mrow> <ob:mi>s</ob:mi> </ob:mrow> <ob:mrow> <ob:mi>N</ob:mi> <ob:mi>N</ob:mi> </ob:mrow> </ob:msub> </ob:mrow> </ob:msqrt> <ob:mo>≤</ob:mo> <ob:mn>62.4</ob:mn> <ob:mtext> </ob:mtext> <ob:mtext> </ob:mtext> <ob:mi>GeV</ob:mi> </ob:mrow> </ob:math> . While we find good agreements for <qb:math xmlns:qb="http://www.w3.org/1998/Math/MathML" display="inline"> <qb:msqrt> <qb:msub> <qb:mi>s</qb:mi> <qb:mrow> <qb:mi>N</qb:mi> <qb:mi>N</qb:mi> </qb:mrow> </qb:msub> </qb:msqrt> <qb:mo>≥</qb:mo> <qb:mn>39</qb:mn> <qb:mtext> </q