Compatibility and combination of world W-boson mass measurements

Abstract

The compatibility of <jats:italic>W</jats:italic>-boson mass measurements performed by the ATLAS, LHCb, CDF, and D0 experiments is studied using a coherent framework with theory uncertainty correlations. The measurements are combined using a number of recent sets of parton distribution functions (PDF), and are further combined with the average value of measurements from the Large Electron–Positron collider. The considered PDF sets generally have a low compatibility with a suite of global rapidity-sensitive Drell–Yan measurements. The most compatible set is CT18 due to its larger uncertainties. A combination of all <jats:inline-formula><jats:alternatives><jats:tex-math>$$m_W$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>m</mml:mi> <mml:mi>W</mml:mi> </mml:msub> </mml:math></jats:alternatives></jats:inline-formula> measurements yields a value of <jats:inline-formula><jats:alternatives><jats:tex-math>$$m_W = 80{,}394.6 \pm 11.5$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>m</mml:mi> <mml:mi>W</mml:mi> </mml:msub> <mml:mo>=</mml:mo> <mml:mn>80</mml:mn> <mml:mo>,</mml:mo> <mml:mn>394.6</mml:mn> <mml:mo>±</mml:mo> <mml:mn>11.5</mml:mn> </mml:mrow> </mml:math></jats:alternatives></jats:inline-formula> MeV with the CT18 set, but has a probability of compatibility of 0.5% and is therefore disfavoured. Combinations are performed removing each measurement individually, and a 91% probability of compatibility is obtained when the CDF measurement is removed. The corresponding value of the <jats:italic>W</jats:italic> boson mass is <jats:inline-formula><jats:alternatives><jats:tex-math>$$80{,}369.2 \pm 13.3$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>80</mml:mn> <mml:mo>,</mml:mo> <mml:mn>369.2</mml:mn> <mml:mo>±</mml:mo> <mml:mn>13.3</mml:mn> </mml:mrow> </mml:math></jats:alternatives></jats:inline-formula> MeV, which differs by <jats:inline-formula><jats:alternatives><jats:tex-math>$$3.6\sigma $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>3.6</mml:mn> <mml:mi>σ</mml:mi> </mml:mrow> </mml:math></jats:alternatives></jats:inline-formula> from the CDF value determined using the same PDF set.