Register to reply 
What kinds of particles can decay to Lambda hyperons? 
Share this thread: 
#1
Jun1014, 08:32 AM

P: 27

Such as ##\Sigma^0 \to \bar{\Lambda}\gamma\gamma##.
I want to make a complete collection of all these decay modes, i.e. ##X \to \Lambda / \bar{\Lambda} + \cdots##. At least some major channels. 


#2
Jun1014, 10:12 AM

P: 1,010

wouldn't the pdg help you?



#3
Jun1014, 07:59 PM

P: 27

If there isn't a readymade collection, I'll try to search one by one in PDG. Thanks all the same. 


#4
Jun1014, 08:55 PM

Emeritus
Sci Advisor
PF Gold
P: 16,458

What kinds of particles can decay to Lambda hyperons?
Any baryon weighing more than 1115 MeV.
Any other particle weighing more than 2230 MeV. 


#5
Jun1114, 01:24 AM

P: 27




#6
Jun1114, 01:35 PM

Mentor
P: 12,028

I guess you look for particles that frequently produce Lambdas? Then look for baryons with two light quarks (up/down) and one heavier quark (especially strange and charm, but also bottom). In addition, some Bmesons can decay to lambda+X. Z and W can produce lambdas as well, but those are quite rare. For very highenergetic lambdas, they might be relevant. Where/how do you want to use such a collection? 


#7
Jun1114, 08:11 PM

Emeritus
Sci Advisor
PF Gold
P: 16,458




#8
Jun1114, 08:21 PM

P: 27

##\frac{\sum Z \to {\Lambda}/\bar{\Lambda} + X}{\sum Z \to X}## = 40% ? 


#9
Jun1114, 09:06 PM

Emeritus
Sci Advisor
PF Gold
P: 16,458

No, I mean that in a sample of a million Z decays there are 400,000 Lambdas. It's a statistical statement, not event by event.



#10
Jun1214, 03:24 AM

PF Gold
P: 472

If you are looking for things beside shortdistance production and the Z production just look at any heavier baryonic resonance and see what can give you the most Lambdas. Your end goal is a [uds]. So you can have some
##[uds]^* \to [uds] + (f \bar{f},\pi \pi, \gamma)## Resonant decays ##[\Lambda^*]## ##[udc] \to [uds] + \left(f \bar{\nu}_f, \pi^{+}, \rho^{+}, etc\right) ## electroweak decays ##[\Lambda_c, \Sigma_c, \Xi_c]## ##[udb]> [uds] + f \bar{f}## (FCNC, highly suppressed) ##[\Lambda_b, \Sigma_b, \Xi_b]## 


#11
Jun1414, 11:42 AM

Mentor
P: 12,028

At the LHC, the crosssections are 100nb for the W and 30nb for the Z (ATLAS result at 7 TeV). I didn't find a proper crosssection measurement of the lambda at the LHC, but an approximate number of 100µb given here (note: those lines are "100 events"), and I think this is restricted to the LHCb acceptance  that means the total crosssection is significantly higher. For the total number of lambdas, W and Z contribute less than .1%. That number could be larger for large transverse momentum. For all other accelerators, the energy is lower, and the W/Z crosssection goes down faster than the other production modes, so there the contribution is even smaller (unless you run an electronpositron collider at the Z peak, of course). I found a master thesis with a collection of (predicted) mother particles for Lambdas at LHCb. 


Register to reply 
Related Discussions  
Interference between different kinds of particles  Quantum Physics  13  
Lambda > n + pi^0 decay  High Energy, Nuclear, Particle Physics  1  
Why do gamma rays accompany other kinds of decay?  High Energy, Nuclear, Particle Physics  3  
If particles always decay into particles of smaller mass, how are larger particles...  Quantum Physics  4  
Decay equations: Given A0 &amp;amp; At, find halflife, lambda and N0  Introductory Physics Homework  14 