Scalar quantities

The arguments I,J,K,L are ALPHA ``track'' numbers.

QCT (I)

cos (polar angle)

QPH (I)

PHi = azimuth (radians)

QPT (I)

Transverse momentum (with respect to the beam line)

QBETA (I)

beta (see 8.1.1 for mass assumption)

QGAMMA (I)

gamma

Note:

Returned masses are negative if (E² - p²) is negative.

QMSQ2 (I,J)

(invariant mass)² of particles I and J

QM2 (I,J)

invariant mass of particles I and J

QMSQ3 (I,J,K)

(invariant mass)² of particles I, J, and K

QM3 (I,J,K)

invariant mass of particles I, J, and K

QMSQ4 (I,J,K,L)

(invariant mass)² of particles I, J, K, and L

QM4 (I,J,K,L)

invariant mass of particles I, J, K, and L

QDMSQ (I,J)

mass² of the 4-momentum difference p(I) - p(J). In a decay I -> J + x, QDMSQ(I,J) gives the mass² of x.

QPPAR (I,J)

momentum component of particle I parallel to particle J

QPPER (I,J)

momentum component of particle I perpendicular to particle J

QDOT3 (I,J)

scalar product of momentum vectors I and J (3-vectors)

QDOT4 (I,J)

scalar product of 4-vectors I and J = QE(I) * QE(J) - QDOT3(I,J)

QCOSA (I,J)

cos (angle between tracks I and J) (lab frame)

QDECA2(I,J)

cos (decay angle): In a two-body decay x $\rightarrow$ I + J, the decay angle is the angle between particle x and particle I, measured in the rest frame of particle x (i.e., the angle between the boost direction and particle I).

QDECAN(I,J)

extension of QDECA2 for the n-body decay I $\rightarrow$ J + any. Note the different meaning of the first argument in QDECA2 and QDECAN.

QMDIFF(I,'part')

mass difference between I and particle table mass of `part'.

QMCHI2(I,'part')

$\chi^{2}_{}$ resulting from mass difference between I and particle table mass of `part'. This function is equivalent to

(QM(ITK) - QPMASS('part-name'))²/QSIGMM(ITK).

QMCHIF(I)

$\chi^{2}_{}$ of mass-constrained fit (KVFITM or KVFITA - see 9.3). QMCHIF(I)=-1 if track I was not the result of a fit.

QVDIF2(IV1,IV2)

distance between vertices IV1 and IV2 in r - $\phi$ (see 9.4).

QVDIF3(IV1,IV2)

distance between vertices IV1 and IV2 in 3 dimensions (see 9.4).

QVCHIF(IV)

$\chi^{2}_{}$/NDF of vertex fit for vertex IV (KVFITN or KVFITV - see 9.4).