Centauric 1-jettiness in DIS and universal power corrections

A

bstract

We introduce the Centauric 1-jettiness ,

, a generalized event shape for Deep Inelastic Scattering (DIS) with adjustable beam and jet reference vectors and thus beam and jet regions. We demonstrate that a specific choice of weights allows this observable to exactly reproduce the geometric boundaries of the Centauro jet algorithm in the Breit frame. Within the framework of Soft-Collinear Effective Theory (SCET), we derive a factorized cross section in the small-

$$ {\tau}_1^C $$ τ 1 C

region in terms of known perturbative ingredients. This allows the resummation of large logarithms to N ³ LL accuracy, which we then match to fixed-order NLO QCD

$$ \left(\mathcal{O}\left({\alpha}_s^2\right)\right) $$ O α s 2

predictions from NLOJet++. We establish that the soft measurement reduces to a rescaled hemisphere measurement, placing Centauric 1-jettiness in the same universality class, for the leading non-perturbative corrections, as DIS thrust and jet mass. As a consequence, the leading non-perturbative shift depends on the same universal first-moment-shift parameter Ω ₁ and scales exactly as 1/ R with the jet radius, thanks to the boost invariance of the Centauro algorithm along the photon axis in the Breit frame, a scaling that we test using P simulations. These results open new strategies for determining the strong coupling from DIS event shapes, with R providing a handle to break the degeneracy between α _s and the universal non-perturbative shift parameter Ω ₁ .