STAR HardProbes PWG

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

Hello

Yes, traditionally HT2 is the Upsilon trigger, and there is definitely interest in carrying out Upsilon measurements using Run23+25 data. Since we do not have JP triggers in HI running, I thought a HT trigger is also used for jet measurement, but I am not sure which one it is. 

The HT2 trigger is around 4.2 GeV, designed for Upsilon. Of course, lower threshold will probably help, but the rate will increase quickly, sampling less luminosity due to inevitable pre-scaling.  For example, the rate for HT1 is very high (5 kHz at high-lumi running), so it has to be heavily pre-scaled. As to what the pre-scale should be, more discussions and thoughts are probably needed. 

Nihar: we do have sub-structure measurements outlined in BUR for Au+Au. See Fig. 66, right panel: https://drupal.star.bnl.gov/STAR/system/files/STAR_BUR_Runs23_25_2022.pdf. 

Best

Rongrong

On Jun 19, 2023, at 1:35 PM, Leszek Kosarzewski <leszek.kosarzewski AT gmail.com> wrote:

Hello Nihar, Rongrong and Isaac

I can only quickly add that BHT1 will work for low-pT Upsilons, but depending on the prescales may not sample the whole integrated luminosity. The BHT2 (or BHT3) should sample the entire integrated luminosity (again depending on prescales/thresholds). This is my experience from past runs.

Best regards, Leszek

pon., 19 cze 2023 o 19:20 Nihar Sahoo via Star-hp-l <star-hp-l AT lists.bnl.gov> napisał(a):

Hello Rongrong,

If I am not wrong, I think the jet sub structure measurement in BUR was
for pp, not heavy ion. Is not that?
But one can still use BHT1 trigger for those measurements.

However, As Carl mentioned in his email, we have also plan for Upsilon
measurement. Then can’t we use lower threshold trigger for the Upsilon
measurement? Just asking to know being a non expert.


Nihar

On 2023-06-19 22:33, Ma, Rongrong wrote:
> Hello Nihar
>
> I think we have sub-subtructure measurements mentioned in the BUR.
> Even if not mentioned in the BUR, Run23+25 dataset still provide a
> great opportunity for jet measurements in general, which is why I
> asked what HT trigger do people usually use for such measurements.
>
> Best
> Rongrong
>
>> On Jun 19, 2023, at 1:00 PM, Nihar Sahoo <nihar AT rcf.rhic.bnl.gov>
>> wrote:
>>
>> Hello Rongrong,
>>
>> We do not have any hp physics proposal in the past BUR 23-25 documents
>> for AuAu runs for Jet measurements except gamma trigger.
>>
>> So I guess no one has plan also to analyze BHT2 trigger.
>>
>>> I am not sure who is interested in analyzing BHT1 trigger, but it
>>> could at least serve as the bridge between MB and BHT2 triggers for
>>> trigger bias evaluation
>> It is a good idea. If we need BHT with lower threshold , then BHT1 can
>> serve the purpose.
>>
>>
>> Nihar
>>
>>
>> On 2023-06-19 21:36, Ma, Rongrong via Star-hp-l wrote:
>>> Hello Isaac
>>> For the HP-related triggers, what matters is the sampled luminosity
>>> rather the number of events. Of course, the ideal case would be
>>> sampling full luminosity, but as you noted the rates for dimuon and
>>> BHT1 are too high. For BHT2 (Upsilon) and BHT3 (gamma+jet) triggers,
>>> we should allocate enough bandwidths such that they can sample the
>>> full luminosity.
>>> One question: is the BHT2 trigger used for jet measurements in
>>> general?
>>> For the dimuon trigger, our plan is to tighten the trigger time
>>> window
>>> cut and apply a pre-scale to reduce it to 1 kHz.
>>> I am not sure who is interested in analyzing BHT1 trigger, but it
>>> could at least serve as the bridge between MB and BHT2 triggers for
>>> trigger bias evaluation.
>>> Best
>>> Rongrong
>>>> On Jun 16, 2023, at 5:38 PM, Mooney, Isaac via Star-hp-l
>>>> <star-hp-l AT lists.bnl.gov> wrote:
>>>> Hi all,
>>>> As I mentioned in the PWG meeting on the 8th, we’ve been asked to
>>>> give input on the prescales for HardProbes-related triggers for the
>>>> upcoming high-luminosity data-taking period. Specifically, due to
>>>> high rates from the dimuon and BHT1 triggers, these may require a
>>>> high prescale to limit their bandwidth. Our request is for analyzers
>>>> planning to use Run 23 data with these triggers to provide a desired
>>>> overall number of events for each trigger in order to meet the
>>>> physics goals for the analysis. If we assume a given number of weeks
>>>> of running, this then gives a rough estimate of the prescale we
>>>> should apply.
>>>> I’m also linking my slides from last week
>>> (https://drupal.star.bnl.gov/STAR/system/files/TriggerRates100k_Run23.pdf)
>>>> with a few changes, including a rate table on the last slide
>>>> estimated by Akio, along with some back-of-the-envelope calculations
>>>> I added for the prescale of these two triggers.
>>>> Please let us know if you have any questions or input.
>>>> Thanks,
>>>> Isaac, Nihar, and Yi _______________________________________________
>>>> Star-hp-l mailing list
>>>> Star-hp-l AT lists.bnl.gov
>>>> https://lists.bnl.gov/mailman/listinfo/star-hp-l
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