  New physics at the TeV scale can affect the dynamics of the electroweak phase
transition in many ways. In this note, we evaluate its impact on the rate of
baryon-number violation via sphaleron transitions. We parameterize the effect
of new physics with dimension-6 operators, and we use the Newton-Kantorovich
method to numerically solve the resulting equations of motion. Depending on the
sign of the coefficient of the dimension-6 operators, their presence can either
increase or decrease the sphaleron energy at the level of a few percent,
parametrically of order $m_W^2 / \Lambda^2$ where $\Lambda$ is the scale
suppressing the dimension-6 operator. The baryon-number washout condition,
typically written as $v_c / T_c > 1$, is directly proportional to the sphaleron
energy, and we discuss how the presence of dimension-6 operators can affect
electroweak baryogenesis.
