analysesanalyses.
bRUH
55 Matching Annotations
- Aug 2025
-
www.ep1.rub.de www.ep1.rub.de
-
-
www.ep1.rub.de www.ep1.rub.de
-
Scalar factors have been absorbed into a single complex-valued scalar factor
Explain why?
-
- May 2025
-
ep1.rub.de ep1.rub.de
-
BESIII Collaboration et al. (2024) generated
liesst sich irgenwie komisch
-
chi-square
Willst du das ausschreiben?
-
these
maybe the cuts mentioned before oder the aforementioned cutes? These ist immer so ...
-
least 50 MeV
an energy of?
-
o restriction is placed on the maximum number of detected photons.
You already mention this later when you decribe the selection constraints
-
(10 billion)
doppelt gemoppelt
-
was based
is based? Geht es da um das alte AmpForm?
-
as implemented in AmpForm (Fritsch et al., 2025).
Bzw willst du sagen dass es nen neues AmpForm gibt? Dann wuerde ich recent version oder so schreiben
-
De Boer et al. (2023).
Nice ;D
-
visualizations
Kings language or not?
-
Φ all remaining
being
-
Minuit2
Hast du KURZ irgendwo beschrieben was das ist?
-
(−1)L=+1 and (−1)L=−1,
Beschreibe was L ist
-
-
ep1.rub.de ep1.rub.de
-
to
the
-
are
is?
-
we see here a
where?
-
Vectorization
are u using american or british english? Oder ist das nen eigener name?
-
a
an?
-
implement
implemented
-
(call them scalar-based loops)
call them?
-
symbolic amplitude models.
vielleicht eher "how symbolic models support this"
-
- Jan 2025
-
www.ep1.rub.de www.ep1.rub.de
-
General scattering amplitude
I like this part maybe put this general explaintion of S matrix somewhere else? Because you also need this for the whole dynamics section and i also an explaination why you can factor out the mag. of the momentum in the whole spin state basis chapter you wrote before
-
:
In this equation what is D(R) specifically what is R in this case. Rotation but what Rotation?
-
introduces a rotation R∘ that rotations the quantisation axis z of the two-particle state over θ,ϕ into the p→1 direction. So if we define |00λ1λ2⟩ to be the rotated state, we can notate the equivalent of
Would explicly mention that the angles are picked to be zero here. You only mention indirectly in the equation/Bratket. Also maybe explain why you pich these angles to be zero. This is done as a trick to get a state which is an eigenstate of Jz and lambda1-lambda2=M. This helps you to define the the transformation D between the plane wave basis and the spherical basis with definite J. If i understood correctly.
-
To do This is simply a copy of Equation (4.11) in Suh-Urk Chung (2014), but it needs a better motivation/explanation.
I think you can factor out the absolute of p because you are in cm frame and the plane wave basis is an eigenstates of the total four Momentum. This is described in Richmann. You described this before with the cannonical basis.
-
The construction of two-particle states requires understanding of the tensor product of two spin
Would also mention why you exactly describe this. You do this because the two particle state is the tensor product of the one particle states you derived earlier
-
spatial rotation
Later you change to polar coordinated phi, theta, 0. I would mention this somewhere
-
to p
the
-
Tensor products
Keine Ahnung ob das so wichtig ist das im Main text zu beschreiben. Vielleicht ist das eher was für den Anhang. Damit wird ja eigenlich nur motiviert woher die Clebsch Gordan Koeffizienten kommen. Also wenn du das Tensorprodukt von zwei irreduzible Darstellung wie hier |JM> Basen machst, kommt ne reduzieble darstellung raus die dann mit den CG-Koeffizienten ausreduziert wird.
-
arbitrary direction
Why the switch from a, b, gamma the polar angles? Why do we do this why is it more suitable?
-
boosts in the same direction as p→.
in general helicity is NOT invariant under Lorentz boosts. They can change the sign. Only in the defined koordinate system it is. For rotations this is always the case not only if you boost into momentum direction.
-
pin projection the helicity
the spin projection on the QUANTISATION AXIS
-
Crucially, using the fact that the U operator is multiplicative,
The unitarity operator U. Frankly a bit confusing because you use U(R), U(L) and U
-
R˚ and then rotating back with R˚−1:
I your case: What is the difference between R and R° ?
-
infinitesimal generator operat
was bedeutet das?
-
Lorentz transformations, or “boosts”.
Lorentz Transformationen sind doch nicht nur Boosts oder? Also im deutsch ist Lorentz Trafo alles also Rotation, Spieglung und Boost. Nur boost alleine ist dann spezielle Lorentz Trafo.
-
operator U[L]. It rel
the R(Operator) convention: same as with the rotation stuff. Cant you just say that it a unitarity operator
-
unitary operator U[R] represents the effect of rotation R on the spin state |jm⟩. T
I don not get the difference or the need of distinguishing between R an U(R). The formulation of R here is not unitarity? Eigentlich is doch die Darstellung über die Wigner-D matrizen die anwendung auf der Drehung auf die |jm> basis. Das was du im folgenden als U(R) definierste is doch so ne allgemeine Darstellung des Operators?
-
(actively)
what does active mean compared to inactive? Why do we have an active rotation?
-
zyz convention.
? what is the zyz convention. Relation to Euler angels a, b, gamma. More description
-
This allows us to write the unitary operator for the zyz rotation as
the rotation operator in the three dim case is a 3X3 matrix or?
-
These matrices are the matrix elements of the Jy component of the angular momentum operator and of the unitary operator in the basis of spin states |jm⟩, that is
I do not get this sentence at all. Just say that the Wigner D matrices are 2j+1 dimanesional matrices.
-
where dm′mj and Dm′mj ar
What you list here in the formula is the definition of the matrix ELEMENTS? right?
-
Wigner d‑matrices and D‑matrices,
Aren't they called Wigner D and small Wigner d?
-
Constructing amplitudes with the helicity formalism requires a good understanding of the effect on Lorentz boosts and rotations on spin states.
I would mention here that the boosts and Rotations you define later are need to transform between the Cannonical and the Helicity system. Or derive the helicity system from the cannonical.
-
single, massive1
I saw the annotation. Is this relevant? As far as I understood the helicity is even better suited for massless particle because it is better defined in relativistic cases... or something like this Also as i remember somewhat described in the Jacob&Wick paper i send before.
-
ome quantisation axis (say, the z axis).
some arbitrary axis e.g. z-axis
-
elates to the scattering matrix.
-
-
www.ep1.rub.de www.ep1.rub.de
-
Crossing symmetry
I would put crossing symmetry and dispersion relation under analytic continuation as they are both (as far as I understood) a form of a.c. but for different cases right? C.s for negative s or whatever is on the x axis... and Dispersion for the whole branch cut negative complex plane stuff?
-
|ψin⟩.
Maybe define the wave functions as expansions in momentum space to describe that the S matrix elements parameterizes the probabillity expamnsion for the incoming state to become the outgoing state?
-
Constraints
Nice :)
-
and it is where the S matrix comes in.
Comes in? Unclear. More like: '' Is a way to express this condition'', right?
-
particles interact.
only interaction what is with what they are composed of? E.g- find tetraquark?
-