STAR HardProbes PWG

["Ma, Rongrong" <marr AT bnl.gov>]

Hello Again

Jamie just mentioned that the 20 B MB events should correspond to about 3 
nb^-1. This corresponds to what a HT trigger with pre-scale of about 13 can 
sample. 

Best
Rongrong

> On Jun 21, 2023, at 12:41 PM, Ma, Rongrong via Star-hp-l 
> <star-hp-l AT lists.bnl.gov> wrote:
> 
> Hello Nihar, Lijuan
> 
> For the Upsilon paper we just published, a threshold of 18 (HT2) was used. 
> We also published Jpsi cross section in 500 GeV pp collisions using HT2, 
> which covers Jpsi down to 4 GeV/c. The MB sample (20 B) we aim to record 
> should be sufficient for covering low-pT Jpsi, and Upsilon even though 
> Upsilon can already be measured down to 0 pT with HT2 trigger. 
> 
> Furthermore, the 20 B MB events roughly correspond to 2 nb^-1 of 
> luminosity. So any HT trigger with a pre-scale larger than 20 will not be 
> very useful, which I think is the case for our current HT1 (threshold = 
> 11). So I think it only makes sense to raise the threshold to 15 if there 
> is physics program requiring it, such that the pre-scale can be smaller 
> than 20. Otherwise, we should probably drop the HT1 trigger. 
> 
> For the question of whether we can use threshold 15 for Upsilon, the answer 
> is yes, However, the issue is that we will not be able to sample the full 
> luminosity with this threshold, which effectively reduces the statistics. 
> So I do not see a strong motivation there. 
> 
> Best
> Rongrong
> 
>> On Jun 21, 2023, at 10:57 AM, Nihar Sahoo via Star-hp-l 
>> <star-hp-l AT lists.bnl.gov> wrote:
>> 
>> Dear Lijuan,
>> 
>> sorry, I could not join yesterday trigger board meeting.
>> 
>> As per BUR 23+25, we have mainly Jet substructure, gamma+jet, J/psi and 
>> Upsilon physics program in Au+Au.
>> 
>> 1) For Jet substructure measurement, HT1 and HT2 with 11 (~2.6 GeV) and 18 
>> (~4.2 GeV), respectively, would be OK.
>> 2) For gamma+jet: BHT3(+L2gamma) 25 (~5.9 GeV); I think this is same with 
>> previous runs; so it is OK.
>> 3) J/psi: probably Lower HT1 threshold 11 (~2.6 GeV)
>> 4)Upsilon: both HT1,2 with threshold 11 and 18 would be Ok.
>> But need to confirm from PAs (Others can comment) if it is Ok to use HT2 
>> as 15 (~3.5) for Upsilon analysis or not.
>> 
>> Thank you
>> Nihar
>> 
>> 
>>> For Run23, we have the following:
>>> BHT1-VPD100: the threshold is 11
>>> BHT2-VPD100: the threshold is 18
>>> BHT3: the threshold is 25
>> 
>> On 2023-06-21 18:54, ruanlj via Star-triggerboard-l wrote:
>>> Hi All,
>>> After yesterday's trigger board meeting, I went to check the BHT
>>> thresholds for Run 16.
>>> As mentioned by Rongrong, there was no BHT2 trigger for hard probes 
>>> physics.
>>> There were two triggers:
>>> BHT1-VPD10: the threshold was set to 16 and later was changed to 15
>>> BHT3: the threshold was 25
>>> For Run23, we have the following:
>>> BHT1-VPD100: the threshold is 11
>>> BHT2-VPD100: the threshold is 18
>>> BHT3: the threshold is 25
>>> My question to hard probes pwg/experts: is the current threshold
>>> setting for BHT triggers good for your physics program?
>>> Lijuan
>>> _______________________________________________
>>> Star-triggerboard-l mailing list
>>> Star-triggerboard-l AT lists.bnl.gov
>>> https://lists.bnl.gov/mailman/listinfo/star-triggerboard-l
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