sPHENIX MAPS tracker discussion

[Ming Liu <ming AT bnl.gov>]

Hi Sookhyun,

Thanks for your quick responses, now I do have better understanding of your nice plots.

 

You answers to slides #3 and #5 questions make me wonder what happens if you also require MBD hits?

For MB events happened within |Z|<10cm, what fraction of the events has track_multiplicty <2? On your slide #2, vertex tagging efficiency is very high, >95% with track_multiplity>=2.

 

Cheers,

Ming

 

-- 

Ming Xiong Liu

P-25, MS H846                     TEL: 505-667-7125 

Physics Division                            631-344-7821(BNL)

LANL                                               630-840-5708(FNAL)

Los Alamos, NM 87545      FAX:  505-665-7020

 

 

From: Sookhyun Lee <dr.sookhyun.lee AT gmail.com>
Date: Saturday, December 1, 2018 at 9:10 PM
To: "Ming Liu (BNL)" <ming AT bnl.gov>
Cc: sphenix-mvtx-l <sphenix-maps-l AT lists.bnl.gov>, <sphenix-intt-l AT lists.bnl.gov>
Subject: Re: [Sphenix-maps-l] Final plots for in-time vertexing with INTT

 

Hi Ming,

 

Thank you for your feedback. Please see answers below. 

Best regards,

Sookhyun

 

On Sat, Dec 1, 2018 at 9:51 PM Ming Liu <ming AT bnl.gov> wrote:

Hi Sookhyun,

 

Thanks for the nice work, I have a few detailed questions about your plots:

 

#1.  For the in-time events, I assume their collision  |Z_vtx| < 10cm, and the out-of-time events have sigma_z_vtx = 40cm, right?

 

That is correct.  I only consider in-time events with z-vertex within +-10cm window. 

 

#3, this is essentially the out-of-time vtx tagging efficiency, at a high  p+p collision rate ~10MHz, with ~10uS integration window of MVTX, we would expect about 100 collisions,  Does this mean you would like to have ~1 miss-identified crossing? Of course, if we can have much shorter integration time (say ~4uS), this miss-tagging rate would be smaller.

 

The performance plots are for integration time window of 4us, and the number of vertices that are reconstructible (related to your next question) will be smaller than 100 collisions at 10us time window. The performance might not be ideal for 10uS integration time window at this moment, but it can be improved by advancing rejection algorithm. This is the best performance so far with 1 INTT layer..  

 

#5, at 12MHz, and ~4uS integration time, I would expect ~12 x 4 = 48 collisions on average, but your plot shows the average # of event vtx ~ 10, do you require hits in both MB/BBC detectors?

 

Thanks for pointing this out, the number of vertices I quote is the ones that are reconstructible and will be used, meaning there has to be more than 1 track that has 3 hits on MVTX, |true vertex| <10cm, |eta|<1.0 and true pT>0.5 GeV/c.  I can make a plot for the number of collisions there are for crosscheck. 

 

 

Cheers,

Ming

 

 

-- 

Ming Xiong Liu

P-25, MS H846                     TEL: 505-667-7125 

Physics Division                            631-344-7821(BNL)

LANL                                               630-840-5708(FNAL)

Los Alamos, NM 87545      FAX:  505-665-7020

 

 

From: sPHENIX-MAPS-l <sphenix-maps-l-bounces AT lists.bnl.gov> on behalf of Sookhyun Lee <dr.sookhyun.lee AT gmail.com>
Date: Saturday, December 1, 2018 at 4:38 PM
To: sphenix-mvtx-l <sphenix-maps-l AT lists.bnl.gov>, <sphenix-intt-l AT lists.bnl.gov>
Subject: [Sphenix-maps-l] Final plots for in-time vertexing with INTT

 

Hi all, 

 

My sincere apologies for delayed posting for final plots for in-time vertexing with INTT. I had to modify codes to properly deal with hermetic INTT layers and the performance improved as a result.

 

Original plots are here if needed:

/gpfs/mnt/gpfs04/sphenix/user/shlee/ittf/plots/final

 

Best regards,

Sookhyun

_______________________________________________ sPHENIX-MAPS-l mailing list sPHENIX-MAPS-l AT lists.bnl.gov https://lists.bnl.gov/mailman/listinfo/sphenix-maps-l