# how to reconstruct the W massin -R mode

Hello,

I use -R mode to reconstruct the W transverse mass (The final state inculde W boson with leptonicly decay) with the code MT_MET(l) , but in my events there is other neutrinos also contributing to missing energy. So how can I reconstruct the W boson mass via the neutrino longitudinal momentum by enforcing MW^2=(pl+pnu)^ 2? How can I definite ET(miss)=pT(nu) in this mode?

Yao-Bei

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2018-12-05
2018-12-05
 Benjamin Fuks (fuks) said on 2018-12-04: #1

Hi Yao-Bei

The MT_MET calculation always considers the full missing (transverse) momentum. If this definition does not suit your need, it is up to you to define a new observable directly in the analysis code.

Regards

Benjamin

> On 2 Dec 2018, at 22:08 , lyb <email address hidden> wrote:
>
> New question #676533 on MadAnalysis 5:
>
> Hello,
>
> I use -R mode to reconstruct the W transverse mass (The final state inculde W boson with leptonicly decay) with the code MT_MET(l) , but in my events there is other neutrinos also contributing to missing energy. So how can I reconstruct the W boson mass via the neutrino longitudinal momentum by enforcing MW^2=(pl+pnu)^ 2? How can I definite ET(miss)=pT(nu) in this mode?
>
>
> Yao-Bei
>
> --

 lyb (liuyaobei) said on 2018-12-05: #2

Hi Benjamin,
How can I define a new observable directly in the analysis code in the -R mode? I cannot find the example to find it in arXiv:1206.1599 and answers in similar questions.
I need to reconstruct the W boson mass from its leptonic decay but in the event there is also other origins for the neutrinos.

Thank you very much if you can tell me how can I define the missing transverse momentum for W leoptonic decay. It is very important to me because this is a problem that I have to solve now.
Best,
Yao-Bei

----- 原始邮件 -----

Benjamin Fuks proposed the following answer:
Hi Yao-Bei
The MT_MET calculation always considers the full missing (transverse)
momentum. If this definition does not suit your need, it is up to you to
define a new observable directly in the analysis code.
Regards
Benjamin
> On 2 Dec 2018, at 22:08 , lyb <email address hidden> wrote:
>
> New question #676533 on MadAnalysis 5:
>
> Hello,
>
> I use -R mode to reconstruct the W transverse mass (The final state inculde W boson with leptonicly decay) with the code MT_MET(l) , but in my events there is other neutrinos also contributing to missing energy. So how can I reconstruct the W boson mass via the neutrino longitudinal momentum by enforcing MW^2=(pl+pnu)^ 2? How can I definite ET(miss)=pT(nu) in this mode?
>
>
> Yao-Bei
>
> --
--
know that it is solved:
If you still need help, you can reply to this email or go to the
following page to enter your feedback:

 Benjamin Fuks (fuks) said on 2018-12-05: #3

Hi Yao-Bei,

https://arxiv.org/abs/1808.00480 <https://arxiv.org/abs/1808.00480>
Many examples are given in there so that you can get inspiration on how to code your observable within the expert mode. In the expert mode, you don't really need to define any observable but instead code it directly. You can for instance code the solutions for the neutrino momentum.

Regards,

Benjamin

> On 5 Dec 2018, at 12:13 , lyb <email address hidden> wrote:
>
> Question #676533 on MadAnalysis 5 changed:
>
>
> lyb is still having a problem:
> Hi Benjamin,
> How can I define a new observable directly in the analysis code in the -R mode? I cannot find the example to find it in arXiv:1206.1599 and answers in similar questions.
> I need to reconstruct the W boson mass from its leptonic decay but in the event there is also other origins for the neutrinos.
>
> Thank you very much if you can tell me how can I define the missing transverse momentum for W leoptonic decay. It is very important to me because this is a problem that I have to solve now.
> Best,
> Yao-Bei
>
>
>
>
> ----- 原始邮件 -----
> 发件人：Benjamin Fuks <email address hidden>
> 主题：Re: [Question #676533]: how to reconstruct the W massin -R mode
> 日期：2018年12月05日 03点37分
>
>
> Benjamin Fuks proposed the following answer:
> Hi Yao-Bei
> The MT_MET calculation always considers the full missing (transverse)
> momentum. If this definition does not suit your need, it is up to you to
> define a new observable directly in the analysis code.
> Regards
> Benjamin
>> On 2 Dec 2018, at 22:08 , lyb <email address hidden> wrote:
>>
>> New question #676533 on MadAnalysis 5:
>>
>> Hello,
>>
>> I use -R mode to reconstruct the W transverse mass (The final state inculde W boson with leptonicly decay) with the code MT_MET(l) , but in my events there is other neutrinos also contributing to missing energy. So how can I reconstruct the W boson mass via the neutrino longitudinal momentum by enforcing MW^2=(pl+pnu)^ 2? How can I definite ET(miss)=pT(nu) in this mode?
>>
>>
>> Yao-Bei
>>
>> --
> --
> know that it is solved:
> If you still need help, you can reply to this email or go to the
> following page to enter your feedback: